Title of Invention	AN EXHAUST VALVE DEVICE
Abstract	The present invention relates to an exhaust valve device comprising a pipe defining a passage therein for passage there through of exhaust gases emitted from the internal combustion engine; a shaft Rota ably extending transversely through said pipe perpendicularly to the axis of the pipe and having at least one end portion projecting from said pipe; an exhaust valve fixedly mounted on said shaft in said pipe for selectively opening and closing said passage; and a junction box for branching a throttle cable.

Title of Invention

AN EXHAUST VALVE DEVICE

Abstract

The present invention relates to an exhaust valve device comprising a pipe defining a passage therein for passage there through of exhaust gases emitted from the internal combustion engine; a shaft Rota ably extending transversely through said pipe perpendicularly to the axis of the pipe and having at least one end portion projecting from said pipe; an exhaust valve fixedly mounted on said shaft in said pipe for selectively opening and closing said passage; and a junction box for branching a throttle cable.

Full Text	GOVERNMENT OF INDIA, THE PATENT OFFICE 2nd M.S.O. BUILDING, 234/4, ACHARYA JAGADISH CHANDRA BOSE ROAD KOLKATTA - 700 020. COMPLETE SPECIFICATION NO. 1912229 DATED: 18-Sep-OO APPLIATION NO. 778 MAS 00 DATED: 18-Sep-OO Divisional to Patent Application No: 1172/MAS/94 Ante-dated to 25th Nov, 1994 ACCEPTANCE OF THE COMPLETE SPECIFICATION ADVERTISED ON 11.10.2003 INDEX AT ACCEPTANCE 107 E , K INTERNATIONAL CLASSIFICATION"—— F 02 D 13/00 TITLE : "AN EXHAUST VALVE DEVICE" APPLICANT : HONDA GIKEN KOGYO KABUSHIKI KAISHA 1-1, MINAMI-A0YAMA2-CH0ME MINATO-KU, TOKYO JAPAN INVENTORS 1.M1TSU0 KUSA; 2. MAS AS HI YOKOYAMA; 3. KAORU HAYASHI; 4. MIKIO SAGARA. THE FOLLOWING SPECIFICATION PARTICULARLY DESCIRBES AND ASCERTAINS THE NATURE OF THIS INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED: - The present invention relates to a mechanism for actuating a device in an internal combustion engine, and more particularly to a mechanism for actuating an exhaust valve, a carburetor valve, or an oil pump in an internal combustion engine such as a two-cycle engine to completely burn an air-fuel mixture in a combustion chamber while preventing blow-by_ when the engine is operating under a low load, for example. Heretofore, it has been customary to employ an electric motor for independently controlling the degree of opening of an exhaust valve or an exhaust throttle valve in a two-cycle engine to completely burn an air-fuel mixture in a combustion chamber while preventing blow-by when the engine is operating under a low load. It has been known to give an exhaust valve predetermined valve opening characteristics with an actuator unit which is disposed in a throttle housing (see Japanese laid-open utility model publication No. 50-153306, for example). This publication discloses a motorcycle having a carburetor valve or a carburetor throttle valve and an exhaust valve. The carburetor valve is actuated by a first wire reel through a wire, and the exhaust valve is actuated by a second wire reel through a wire. These first and second wire reels are housed in a case positioned adjacent to a throttle grip, and can be turned when the throttle grip is turned by the rider of the motorcycle. The case which houses the first and second wire reels is generally referred to as a throttle housing . According to the above publication, since the second wire reel is moved in unison with the first wire reel that is ganged with the carburetor valve, the first wire reel is subject to the load from the second wire reel at all times. Therefore^ when the first wire reel,is quickly returned, the second wire reel is also rotated in unison with the first wire reel. Depending on the exhaust pressure acting on the exhaust valve, the second wire reel may adversely affect the returning motion of the first wire reel, i.e., the quick movement of the carburetor valve to its closed position . In the above publication, the throttle housing is associated with the right-hand grip of the steering handle. The first and second wire reels are positioned as larger- and smaller-diameter reels in the throttle housing, which also houses springs and pins. Consequently, the throttle housing houses a highly complex mechanism. This is because the carburetor valve and the exhaust valve are opened and closed according to different specifications. Motorcycles, particularly small-size scooters, have small-size steering handles. Because various switches are installed on the steering handles near the throttle grip, it is quite difficult to attach a complex, large-size throttle housing, which accommodates first and second wire reels, to the steering handles. The conventional arrangement which employs the electric motor for controlling the exhaust valve is complex in structure and highly costly because it requires various extra mechanical and electrical components. According to the structure shown in the above publication, since various components need to be housed in the throttle housing, there is no layout freedom available for the mechanisms in the throttle housing, On scooters, certain limitations are imposed on the layout of components because the throttle housing should be placed in a steering handle cover. It is therefore an object of the present invent ion to provide a mechanism for actuating a device in an internal combustion engine smoothly with desired characteristics through a simple mechanical arrangement with respect to a throttle opening in response to movement of a throttle cable which is caused by angular movement of a throttle grip, for example, as an accelerator actuating element, According to the present invention, there is provided a mechanism for actuating a device in an internal combustion engine having a throttle cable, comprising a rotor angularly movable in response to movement of the throttle for actuating the device, and lost-motion means for making the rotor idle in a partial stroke of angular movement thereof in actuating the device. The device in the internal combustion engine may comprise an exhaust valve device, which comprises a pipe defining a passage therein for passage therethrough of exhaust gases emitted from the internal combustion engine, a shaft rotatably extending transversely through the pipe perpendicularly to the axis of the pipe and having at least one end portion projecting from the pipe, and an exhaust valve fixedly mounted on the shaft in the pipe for selectively opening and closing the passage. The rotor comprises a drum rotatably fitted over said one end portion of the shaft projecting from the pipe, the throttle cable having an end wound around the drum, the lost-motion means being interposed between the drum and the shaft. The lost-motion means comprises a bracket fixed to said one end portion of the shaft projecting from the pipe, and a spring disposed under compression between the bracket and the drum. The lost-motion means further comprises stopper means for keeping the exhaust valve fully' open after the exhaust valve has been angularly moved from a fully closed position to a fully open position in response to angular movement of the drum. The stopper means comprises a stopper pin mounted on the shaft perpendicularly to the axis thereof for abutment against the pipe in an angular position of the shaft in which the exhaust valve is in the fully open position . The exhaust valve device further comprises return means for returning the shaft to angularly move the exhaust valve from the fully open position to the fully closed position . The device in the internal combustion engine may comprise a junction cable in which the throttle cable is branched. The junction box comprises a case, a shaft disposed in the case and having opposite ends supported by the case, the rotor being rotatably mounted as a first drum on the shafts the throttle cable having an end joined to the first drum, second and third drums rotatably mounted on the shaft successively adjacent to the first .drum, a first branched cable branched from the throttle cable and connected to the first drum under a tension tending to angularly move the first drum in one direction about the shaf, a second branched cable branched from the throttle cable and connected to the second drum under a tension tending to angularly move the second drum in said one direction abour the shaft, and a third branched cable branched from the thrcttle cable and connected to "che third drum under a tension cending to angularly move the third drum in said one directicn abcur the shafT: . The losr-moticn means comprises a first pin mounted on a side of the firsu drum, a first arcuate groove defined in the second drum, the first pin slidably engaging in the first arcuate groove, a second pin mounted en a side of the second drum, and a second arcuate groove defined" in the third drum, the second pin slidably engaging in the second arcuate groove. When the first drumi is .angularly moved in a direction opposite to said one direction by the throttle cable, the-first and second pins engage respective ends of the second and third arcuate grooves, respectively, to allow the second and third drums to angularly move in the direction opposite to said one direction, and when the throttle cable is loosened, the first drum is pulled by the first branched cable and turned "in said one direction, and the first and second pins move toward respective opposite ends of the second and third arcuate grooves, respectively, and thereafter engage the respect'ive opposite ends thereof for allowing the second and third drums to angularly move in said one direc-tion. Accordingly the present invention provides an exhaust valve device comprising a pipe defining a passage therein for passage therethrough of exhaust gases emitted from the internal combustion engine; a shaft rotatably extending transversely through said pipe perpendicularly to the axis of the pipe and having at least one end portion projecting from said pipe; an exhaust valve fixedly mounted on said shaft in said pipe for selectively opening and closing said passage; and a junction box for branching a throttle cable. The parent application No. 1172/MAS/94 describes and claims a mechanism for actuating a device in an internal combustion engine having a throttle cable. The invention will now be described in more detail with reference to embodiments shown in the accompanying drawings, in which; Fig. 1 is a side elevational view of a motorcycle which incorporates the principles of the present invention; FIG. 2 is a side elevational view showing how a junction box and related devices are interconnected in the motorcycle shown in FIG. 2; FIG. 3 is a graph showing opening characteristics of an exhaust valve as required by engine output power; FIG. 4 is a cross-sectional view of an exhaust valve device incorporating a mechanism for actuating a device in an internal combustion engine according to a first embodiment of the present invention; FIG. 5 is a side elevational view of the exhaust valve device shown in FIG. 4; FIG. 6 is a cross-sectional view of the exhaust valve device shown in FIG. 4; FIG. 7(a) is a partly cross- sectional view showing the manner in which an exhaust valve is fully closed when a throttle cable is loosened in the exhaust valve device shown in FIG. 4; FIG. 7(b) is a partly cross-sectional view showing the manner in which the exhaust valve is fully opened when the throttle cable is pulled in the exhaust valve device shown in FIG. 4; FIG. 7(c) is a partly cross-sectional view showing the manner in which the exhaust valve is fully opened, with the throttle cable being shown as further pulled entering a lost-motion condition; FIG. 8(a) is a fragmentary side elevational view of an exhaust valve device incorporating a mechanism for actuating a device in an internal combustion engine according to a second embodiment of the present invention, the view showing the manner in which an exhaust valve is fully closed; FIG. 8(b) is a fragmentary side elevational view of the exhaust valve device shown in Fig. 8(a), showing the manner in which the exhaust valve is fully opened when a throt-tie cable is pulled, the throttle cable being shown as further pulled entering a lost-motion condition; FIG. 9 is a fragmentary side elevational vief, of an exhaust valve device incorporating a mechanism for actuating a device in an internal combustion engine according to a third embodiment of the present invention; FIG. 10 is a fragmentary side elevational view of an exhaust valve device incorporating a mechanism for actuating a device in an internal combustion engine according to a fourth embodiment of the present invention; FIG. 11(a) is a fragmentary plan view of an exhaust valve device incorporating a mechanism for actuating a device in an internal combustion engine according to a fifth embodiment of the present invention, the view showing the manner in which an exhaust valve is fully opened; FIG. 11(b) is a fragmentary plan view of the exhaust valve device shown in FIG. 11 (a), showing the manner in which the exhaust valve is fully opened when a throttle cable is pulled, the throttle cable being shown as further pulled entering a lost-motion condition; FIG. 12(a) is a fragmentary side elevational view of an exhaust valve device incorporating a mechanism for actuating a device in an internal combustion engine according to a sixth embodiment of the present invention, the view showing the manner in which an exhaust valve is fully closed; FIG. 12(b) is a fragmentary side elevational view of the exhaust valve device shown in FIG. 12(a), shov;ing the manner in which the exhaust valve is fully opened; FIG. 13 is a fragmentary cross-sectional view of a junction box incorporating a mechanism for actuating a device in an internal combustion engine according to a seventh embodiment of the present invention; FIG. 14 is an exploded perspective view of a plurality of adjacent drums disposed in the junction box shown in FIG. 13; FIG. 15(a) is a view of the junction box shown in FIG. 13 as viewed in the direction indicated by the arrow "a" when in a fully closed position; FIG. 15(b) is a view of the junction box shown in FIG. 13 as viewed in the direction indicated by the arrow "b" when in a fully closed position; FIG. 15(c) is a view of the junction box shown in FIG. 13 as viewed in the direction indicated by the arrow "c" when in a fully closed position; FIG. 15(d) is a view of the junction box shown in FIG. 13 as viewed in the direction indicated by the arrow "d" when in a fully closed position; FIG. 16(a) is a view of the junction box shown in FIG. 13 as viewed in the direction indicated by the arrow "a" when in a fully opened position; FIG. 16(b) is a view of the junction box shown in FIG. 13 as viewed in the direction indicated by the arrow "b" when in a fully opened position; FIG. 16(c) is a view of the junction box shown in FIG. 13 as viewed in the direction indicated by the arrow "c" when in a fully opened position; FIG. 16(d) is a view of the junction box shown in FIG. 13 as viewed in the direction indicated by the arrow "d" when in a fully opened position; FIG. 17 a graph showing opening characteristics of carburetor and exhaust valves operatively connected to the junction box shown in FIG. 13; FIG, 18 is a fragmentary cross-sectional view of a modification of the junction box shown in FIG. 13; and FIG. 19 is a rear elevational view of a steering handle and related parts of a scooter which has the junction box shown in FIG. 13 or 18. Preferred embodiments of a mechanism for actuating a device in an internal combustion engine will be described in detail below. FIG, 1 shows a motorcycle 1 which incorporates the principles of the present invention. As shown in FIG. 1, the motorcycle 1 has a front wheel 2, a front fork 4, a steering handle 5, a head pipe 6, a cowling 1, a body frame (not shown) disposed in the cowling 7, a rider's seat 8, a swing arm 9, and a rear wheel 10. An internal combustion engine 11 is mounted on the body frame substantially centrally in the motorcycle. The engine 11 has a forwardly inclined cylinder block 12 (see also FIG. 2) from which an exhaust pipe 13 extends rearward. The exhaust pipe 13 has a read end connected through an exhaust throttle valve device or exhaust valve device 15 to an expanded exhaust pipe 14 which is positioned on the right-hand side of the motorcycle and has a rear end connected to a muffler 3. The engine also includes an intake passage having a carburetor throttle valve device or carburetor valve device 17, and an oil pump 18 is positioned near the carburetor valve device 17. A junction box 30 is attached to the body frame directly or through a bracket (not shown). FIG, 2 shows how the junction box 30 and related devices are interconnected. A throttle cable 23 extends from a throttle housing 22 that is positioned adjacent to a throttle grip 21 (accelerator actuating element) to the junction box 30 in which the throttle cable 23 is branched into three cables. These three cables, which extend from the junction box 30, include a cable 24 for the carburetor valve device 17, a cable 25 for the oil pump 18, and a cable 26 for the exhaust valve device 15. The cable 24 is led to the carburetor valve device 17, the cable 25 to the oil pump 18, and the cable 2 6 to the exhaust valve device 15 for actuating these devices. These cables 24, 25, 26 are actually covered with sheaths, and cannot actually be seen. However, these cables 24, 25, 26 and the sheaths will collectively be referred to as cables . The exhaust valve device 15 has an exhaust valve which is required to have such opening characteristics (i.e., the relationship between the angular displacement of the throttle grip and the opening of the exhaust valve) that, as shown in FIG, 3, the exhaust valve increases its opening substantially linearly until it is fully opened when the throt- the grip 21 is turned θa θa = 30 - 50 % of the full angular displacement of the throttle grip 21), and the exhaust valve subsequently remains fully open until the throttle grip 21 is fully angularly moved (a lost-motion condition), Mechanisms for actuating a device in an internal combustion engine according to first through sixth embodiments of the present invention, which will be described below, have a lost-motion mechanism for achieving such opening characteristics. FIGS. 4 and 5 show an exhaust valve device 15 incorporating an actuating mechanism according to a first embodiment of the present invention. The exhaust valve device 15 has a pipe 120 defining a passage therein for passage therethrough of exhaust gases emitted from the engine 11, a shaft 121 rotatably extending transversely through the pipe 120 and having opposite end portions projecting from the pipe 120 perpendicularly to the axis of the pipe 120, an exhaust valve 122 fixedly mounted on the shaft 121 in the pipe 120, and a drum or rotor 123 rotatably fitted over one of the projecting end portions of the shaft 121. The shaft 121 is rotatably supported through bearings 124 in brackets 125, 126 which have ends fitted in the pipe 120. The exhaust valve 122 is a plate valve having a size which is substantially equal to an oblique cross-sectional area of the pipe 120 at an angle θb of 30 degrees, for example, to the axis of the pipe 120, as shown in FIG. 6. The exhaust valve 122 is fixed to the shaft 121 such that it lies at the angle θb to the axis of the pipe 120 when the exhaust valve 122 is fully closed, and cannot be turned in the closing direction, Over one of the end portions of the shaft 121, there are successively fitted a drum 123 through a bearing 127, and a bracket 128. One end of the branched throttle cable 2 6 is wound around the drum 123. The bracket 128 is fixed to the shaft 121 by a threaded nut 129. A spring 130 for pressing the drum 123 is disposed under compression be- tween the drum 123 and the bracket 128. Over the other end portion of the shaft 121, there is fitted a pair of spaced spring holders 132a, 132b which support a return spring 131 therebetween around the shaft 121 as returning means for returning the exhaust valve 122 into a fully closed condition. The return spring 131 has an end en gaging a spring hook 133 that is fixed to the bracket 126, and the other end engaging a hook (not shown) on the spring holder 132a. The spring holders 132a, 132b are fixed to the shaft 121 by a threaded nut 134. The spring holder 132b is held against the bracket 12 6, A stopper pin 135 is fixed to the shaft 121 perpendicular to the axis thereof. When the shaft 121 is turned, the stopper pin 135 can abut against a first edge portion of the bracket 125 (see FIG. 7(a)) or a second edge portion of the bracket 125 (see FIG. 7(b)). When the stopper pin 135 abuts against the first or second edge portion of the bracket 125 in an angular position of the shaft 121 in which the exhaust valve 122 is fully closed or opened, the exhaust valve 223 is held in the fully closed or open position. A washer 136 fitted over the shaft 121 is held against the bracket 125 and retained in place by an E-ring 137 fitted over the shaft 121. Operation of the actuating mechanism according to the first embodiment will be described below with reference to FIGS, 7(a) through 7(d). FIG. 7(a) shows the manner in which the exhaust valve 122 is fully closed with the throttle grip 21 is not operated. In this condition, the spring holder 132a fixed to the shaft 121 is turned in the direction indicated by the arrow A under the bias of the return spring 131. The shaft 121 is therefore rotated until the stopper pin 135 fixed to the shaft 131 abuts against the first edge portion of the bracket 125 whereupon the exhaust valve 122 secured to the shaft 121 is fully closed. Even though the exhaust valve 122 is in the fully closed position, there is a slight gap or clearance left between the inner circumferential surface of the pipe 120 and the outer circumferential edge of the exhaust valve 122. FIG. 7(b) shows the manner in which the exhaust valve 122 is fully opened when the throttle grip 21 is turned a certain angular displacement (ranging from 30 to 50 % of the full angular displacement), i.e., when the throttle grip 21 is turned θa in FIG. 3. Specifically, the throttle grip 21 is turned a certain angular displacement (ranging from 30 to 5 0 % of the full angular displacement) from the position shown in FIG, 7 (a), pulling the throttle cable 26 in the direction indicated by the arrow B (FIG, 7(b)) against the bias of the return spring 131. Although the drum 123 is rotatably fitted over the shaft 121 through the bearing 127, the drum 123 and the shaft 121 are angularly moved together in a direction opposite to the direction A under the forces of the spring 130. The shaft 121 is angularly moved θb until the stopper pin 135 abuts against the second edge portion of the bracket 125, whereupon the exhaust valve 122 has been turned from the fully closed position to the fully open position, FIG. 7 (c) shows the manner in which the exhaust valve 122 remains fully open even when the throttle grip 21 is turned the full angular displacement. Specifically, the throttle grip 21 is turned the full angular displacement from the position shown in FIG. 7(b), further pulling the throttle cable 26 in the direction B. The drum 123 then rotates around the shaft 121 against the forces of the spring 130. During this time, though the throttle cable 26 is further pulled, the throttle valve 122 remains in a lost-motion condition in which it is not operated (the throttle grip 21 is turned from the angular displacement θa to the full angular displacement in FIG. 3) . Therefore, the throttle valve 122 is maintained in the fully open position. Stated otherwise, the angular movement of the drum 123 during this time is idling movement, not affecting the exhaust valve 122, When the throttle grip 21 is fully returned, the shaft 121 is turned back under the bias of the return spring 131 to angularly move the exhaust valve 122 from the open position to the closed position. The exhaust valve 122 is not fully closed as shown in FIG. 7(a). FIGS. 8(a) and 8(b) are fragmentary side eleva-tional views of an exhaust valve device 140 incorporating a mechanism for actuating a device in an internal combustion engine according to a second embodiment of the present invention. As shown in FIGS. 8(a) and 8(b), the exhaust valve device 140 comprises a pipe 141 defining a passage therein for passage therethrough of exhaust gases emitted from the engine 11, a shaft 142 rotatably extending transversely through the pipe 141 and having opposite end portions projecting from the pipe 141 perpendicularly to the axis of the pipe 141, an exhaust valve 143 fixedly mounted on the shaft 142 in the pipe 141, and a link mechanism 144 engaging one of the projecting ends of the shaft 142, The link mechanism 144 comprises an arm 145 having one end fixed to the shaft 142 and supporting a pin 146 mounted on the other end thereof, and a guide wing or rotor 148 having a guide slot 247 defined in an end portion thereof and guiding the pin 14 6 and an opposite end portion connected to an end of the throttle cable 26. The guide wing 148 is angularly movably mounted on an outer surface of the pipe 141 by a shaft 149 which is fixed to the pipe 141 and has an end extending through a substantially central portion of the guide wing 148. The end of the throttle cable 26 is connected to the guide wing 148 by a joint 150 that is coupled to the end of the throttle cable 2 6 and angularly movably fitted over a shaft 151 which is fixed to the opposite end portion of the guide wing 148. Operation of the actuating mechanism shown in FIGS. 8(a) and 8(b) will be described below. FIG. 8(a) shov.'s the manner in which the exhaust valve 143 is fully closed;, i.e., lies at an angle G^ to the axis of the pipe 141. When the throttle grip 21 is then turned to pull the throttle cable 2 6 in the direction indicated by the arrow C, the guide wing 148 is turned about the shaft 14 9 in the direction indicated by the arrow D against the bias of a return spring (not shown) having one end engaging the pipe 141 and the other end engaging the guide wing 148, Since the pin 146 on the arm 145 fixed to the shaft 142 slidably rides in the guide slot 147 in the guide wing 148, the pin 14 6 moves along the guide slot 147 from an end 147a thereof toward an opposite end 147b thereof, during which time the arm 145 is turned. The shaft 142 is also turned in unison with the arm 145 until the pin 146 reaches a corner 147c of the guide slot 147 between its ends 147a, 147b, whereupon the exhaust valve 143 is fully opened. At this time, the throttle grip 21 has been turned θa in FIG. 3. When the throttle grip 21 is further turned the full angular displacement, pulling the throttle cable 26 in the direction C, the arm 145 is not turned because the portion of the guide slot 147 extending between the corner 147c and the end 147b is arcuate around the shaft 14 9 and moves loosely around the pin 146. Consequently, the exhaust valve 143 remains fully open regardless of the additional pulling of the throttle cable 26. Specifically, the guide slot 147 includes a first slot section extending from the end 147a to the corner 147c and spaced progressively farther from the center of the shaft 149, and a second slot section extending contiguously from the corner 147c to the end 147b and spaced a constant distance from the center of the shaft 14 9, FIG- 8(b) shows the manner in which the exhaust valve 143 is in a lost-motion condition while the throttle grip 21 is being turned from the angular displacement θa to the full angular displacement. When the throttle grip 21 is turned the full angular displacement, the guide wing 148 is fully nurned in the direction D about the shaft 14 9, with the end 147b of the guide slot 147 being positioned closely to the pin 14 6. When the throttle grip 21 is fully returned, the exhaust valve 143 is returned to the fully closed position shown in FIG- 8(a) under the resiliency of the non-illus-trated return spring. Since the link mechanism 144 serves as a lost-mo-tion mechanism, desired opening characteristics of the exhaust valve 143 can be achieved simply by the configuration of the guide slot 147. The non-illustrated return spring in the exhaust valve device 140 may comprise a return spring similar to the return spring 131 in the exhaust valve device 15 according to the first embodiment, the return spring being mounted on the end of the shaft 142 opposite to the end thereof which is connected to the arm 145 associated with the guide wing 148. FIG. 9 shows an exhaust valve device 160 incorporating a mechanism for actuating a device in an internal combustion engine according to a third embodiment of the present invention. The exhaust valve device 160 comprises a pipe 161 defining a passage therein for passage therethrough of exhaust gases emitted from the engine 11, a shaft 162 rotatably extending transversely through the pipe 161 and having opposite end portions projecting from the pipe 161 perpendicularly to the axis of the pipe 161, an exhaust valve 163 fixedly mounted on the shaft 162 in the pipe 161, and an arm 164 fixed at its center to one of the projecting ends of the shaft 162. The arm 164 supports on one end thereof a fixed pin 165 over which there is fitted one end of an attachment 166 connected at the other end thereof to the throttle cable 26. The other end of the arm 164 can be held in abutment against a stop 167 mounted on the pipe 161 when the arm 164 is turned to a certain angular position in which the exhaust valve 163 is fully open. A spring 168 is connected in the throttle ca- ble 26 in series therewith near the attachment 166. The actuating mechanism according to the third embodiment operates as follows: FIG. 9 shows the manner in which the exhaust valve 163 is fully closed with the throttle grip 21 not turned. When the throttle grip 21 is turned to pull the throttle cable 26 in the direction indicated by the arrow E, the arm 164 is turned about the shaft 162 in the direction indicated by the arrow F against the bias of a return spring (not shown) which has one end joined to the pipe 161 and the other end to the arm 164, and the shaft 162 is also turned in- unison with the arm 164. When the other end of the arm 164 abuts against the stop 167, the exhaust valve 163 is fully opened. At this time, the throttle grip 21 is turned θa in FIG. 3, When the throttle grip 21 is further turned the full angular displacement to pull the throttle cable 26 in the direction E, the spring 168 is resiliently stretched. The stretched length of the spring 168 absorbs the stroke of the throttle cable 2 6 after the exhaust valve 163 has been fully opened. The exhaust valve 163 is now in a lost-motion condition in which it is not operated (the throttle grip 21 is turned from the angular displacement θa to the full angular displacement in FIG. 3) regardless of the further pulling of the throttle cable 26. Therefore, the exhaust valve 163 is maintained in the fully open position. When the throttle grip 21 is fully returned, the exhaust valve 163 is returned to the fully closed position shown in FIG. 9 under the resiliency of the non-illustrated return spring. The return spring 168 connected in the throttle cable 26 in series therewith serves as a lost-motion mechanism for the exhaust valve 163. The non-illustrated return spring in the exhaust valve device 160 may be arranged in the sanae manner as the return spring 131 in the exhaust valve device 15 according to the first embodiment. FIG. 10 shows an exhaust valve device 170 incorporating a mechanism for actuating a device in an internal combustion engine according to a fourth embodiment of the present invention. The exhaust valve device 170 comprises a pipe 171 defining a passage therein for passage therethrough of exhaust gases emitted from the engine 11, a shaft 172 rotatably extending transversely through the pipe 171 and having opposite end portions projecting from the pipe 171 perpendicularly to the axis of the pipe 171, an exhaust valve 173 fixedly mounted on the shaft 172 in the pipe 171, and an arm 174 fixed at a portion near an end 174a thereof to one of the projecting ends of the shaft 172. The end 174a of the arm 174 can be brought into abutment against a stop 171 mounted on the pipe 171. The arm 174 has an opposite end portion 174b with a guide slot 176 defined therein. An attachment 178 is connected at one end thereof to the end of the throttle cable 26 and supports on its other end a fixed pin 177 which is slidably fitted in the guide slot 176. Operation of the actuating mechanism according to the fourth embodiment will be described below. FIG. 10 shows the manner in which the exhaust valve 173 is fully closed with the throttle grip 21 not turned. When the throttle grip 21 is turned to pull the throttle cable 26 in the direction indicated by the arrow G, the arm 174 is turned about the shaft 172 in the direction indicated by the arrow H against the bias of a return spring (not shown) which has one end joined to the pipe 171 and the other end to the arm 174, and the shaft 172 is also turned in unison with the arm 174. When the end 174a of the arm 174 abuts against the stop 175, the exhaust valve 173 is fully opened. At this time, the throttle grip 21 is turned 8a in FIG. 3. When the throttle grip 21 is further turned the full angular displacement to pull the throttle cable 26 in the direction G, the pin 177 moves in and along the guide slot 176 toward an outer end 176a thereof. This movement of the pin 177 absorbs the stroke of the throttle cable 26 after the exhaust valve 163 has been fully opened. The exhaust valve 173 is now in a lost-motion condition in which it is not operated (the throttle grip 21 is turned from the angular displacement θa to the full angular displacement in FIG. 3) regardless of the further pulling of the throttle cable 26. Therefore, the exhaust valve 173 is maintained in the fully open position. When the throttle grip 21 is fully returned, the exhaust valve 173 is returned to the fully closed position shown in FIG. 10 under the resiliency of the non-illustrated return spring. The guide slot 176 and the pin 177 jointly serve as a lost-motion mechanism for the exhaust valve 173. The non-illustrated return spring in the exhaust valve device 170 may be arranged in the same manner as the return spring 131 in the exhaust valve device 15 according to the first embodiment. FIGS. 11(a) and 11(b) show an exhaust valve device 180 incorporating a mechanism for actuating a device in an internal combustion engine according to a fifth embodiment of the present invention. The exhaust valve device 180 comprises a pipe 181 defining a passage therein for passage therethrough of exhaust gases emitted from the engine 11, a shaft 182 rotatably extending transversely through the pipe 181 and having opposite end portions projecting from the pipe 181 perpendicularly to the axis of the pipe 181 through respective attachment brackets 182a, 182b mounted on the pipe 181, an exhaust valve 183 fixedly mounted on the shaft 182 in the pipe 181, a drum 185 fitted over one of the end portions projecting from the pipe 181, with one end of the throttle cable 26 being wound around the drum 185, and a spring 186 disposed around the shaft 183 under compression between the attachment bracket 182a and the drum 185. The spring 186 has opposite ends coupled to the attachment bracket 182a and the drum 185, respectively. The drum 185 engages the shaft 183 such that the drum 185 axially slides in the direction indicated by the arrow J against the bias of the spring 186 when the throttle cable 26 is subject to a tension greater than a predetermined level in the direction indicated by the arrow I. The actuating mechanism according to the fifth embodiment operates as follows: FIG. 11(a) shows the manner in which the exhaust valve 184 abuts against a stop (not shown) and is fully open when the throttle grip 21 is turned θa in FIG. 3. When the throttle grip 21 is turned to pull the throttle cable 2 6 in the direction indicated by the arrow I to fully open the exhaust valve 184, the drum 185 is moved in the direction indicated by the arrow J against the bias of the spring 18 6. This movement of the drum 185 absorbs the stroke of the throttle cable 26 after the exhaust valve 184 has been fully opened. The exhaust valve 184 is now in a lost-motion condition in which it is not operated (the throttle grip 21 is turned from the angular displacement θa to the full angular displacement in FIG. 3) regardless of the further pulling of the throttle cable 26. Therefore, the exhaust valve 184 is maintained in the fully open position. When the throttle grip 21 is fully returned, the exhaust valve 184 is returned to the fully closed position shown in FIG. 10 under the resiliency of the spring 186. The drum 185 which slides axially when the throttle cable 26 is subject to a tension greater than a predetermined level serves as a lost-motion mechanism for the exhaust valve 184. FIGS. 12(a) and 12(b) show an exhaust valve device 190 incorporating a mechanism for actuating a device in an internal combustion engine according to a sixth embodiment of the present invention. The exhaust valve device 190 comprises a pipe 191 defining a passage therein for passage therethrough of ex- haust gases emitted from the engine 11/ a shaft 192 rotatably extending transversely through the pipe 191 and having opposite end portions projecting from the pipe 191 perpendicularly to the axis of the pipe 191, an exhaust valve 193 fixedly mounted on the shaft 192 in the pipe 191, and a drum 194 fixedly mounted on one of the end portions projecting from the pipe 191. The drum 194 has a portion around which an end of the throttle cable 26 is wound, and that portion of the drum 194 has a radius, or a radial dimension from the axis of the shaft 192, progressively greater in a direction to fully open the throttle valve 193. The actuating mechanism according to the sixth embodiment operates as follows: FIG, 12(a) shows the manner in which the exhaust valve 193 is fully closed with the throttle grip 21 not turned. When the throttle grip 21 is turned to pull the throttle cable 26 in the direction indicated by the arrow K, the drum 194 is turned about the shaft 192 in the direction indicated by the arrow L against the bias of a return spring (not shown) having one end engaging the pipe 191 and the other end engaging the drum 194, and the shaft 192 is also turned in unison with the drum 194. When the drum 194 abuts against a stop (not shown), the exhaust valve 193 is fully opened as shown in FIG. 12(b) with the throttle grip 21 turned θa in FIG. 3, The drum 194 may be replaced with the drum 123 according to the first embodiment or the drum 185 according to the fifth embodiment so as to provide a lost-motion mechanism for absorbing the stroke of the throttle cable 26 after the exhaust valve 193 has been fully opened. When the throttle grip 21 is fully returned, the exhaust valve 193 is returned to the fully closed position shown in FIG. 12(a) under the resiliency of the non-illustrated return spring. The load on the throttle grip 21 may be reduced by positioning the center of the portion of the drum 194 which winds the throttle cable 2 6 therearound and the center of rotation of the drum 194 eccentrically with respect to each other. The non-illustrated return spring in the exhaust valve device 190 may be arranged in the same manner as the return spring 131 in the exhaust valve device 15 according to the first embodiment. In each of the above embodiments, it is necessary to vary the relationship (opening characteristics) between the angular displacement of the throttle grip and the degree of opening of the exhaust'valve depending on the engine type and the engine output power, and such a requirement can be met by a relatively simple and inexpensive actuating mechanism. Since the actuating mechanism is incorporated in and around the exhaust valve in each of the above embodiments, it is possible to employ existing parts including the throttle cable 26, the throttle housing 22, etc. in combination with the actuating mechanism. A mechanism for actuating a device in an internal combustion engine according to a seventh embodiment of the present invention, and a modification thereof will be described below. In the first through sixth embodiments described above, the actuating mechanism is primarily combined directly with the exhaust valve mechanism. In the seventh embodiment, however, the actuating mechanism can be combined with the carburetor valve device and the oil pump as well as the exhaust valve mechanism, and is incorporated in the junction box from which the branched throttle cables extend, as shown in FIGS. 1 and 2. FIG. 13 shows in cross section a junction box 230 incorporating a mechanism for actuating a device in an inter nal combustion engine according to a seventh embodiment of the present invention. The junction box 230 comprises a case 231, a shaft 232 disposed in the case 231 and having opposite ends supported respectively by side walls of the case 231, ' and a plurality of adjacent drums 234, 235, 236 rotatably mounted on the shaft 232 through journal or roller bearings 233, the drums 234, 235, 236 being coupled respectively to a carburetor valve cable 224, an oil pump cable 225, and an exhaust valve cable 226. The drums 234, 235, 236 on the shaft 232 are separate from each other. Pins 237, 238 are mounted on respective sides of the drums 234, 235, and slidably housed in arcuate cam grooves 239, 241, respectively, which are defined in sides of the drums 235, 236. A spring 242 is disposed under compression between one of the side wall of the- case 231 and the drum 236 for normally urging the drums 234, 235, 236 axially in one direction to eliminate unwanted axial play between the drums 234, 235, 236. FIG. 14 illustrates the drums 234, 235, 236 in exploded perspective. The carburetor valve cable 224 is attached at one end thereof to the drum 234 on one axial side thereof, and the throttle cable 23 is attached at one end thereof to the drum 234 on the other axial side thereof. The oil pump cable 225 and the exhaust valve cable 22 6 are attached respectively to the drums 235, 236. The cables 224, 225, 226 are longitudinally tensioned to turn the respective drums 234, 235, 236 about the shaft 232 in the directions indicated by the arrows in FIG. 14. A lost-motion spring 243 (described later on) is connected in the exhaust valve cable 226 in series therewith. The cam grooves 239, 241 are in the form of arcuate grooves, and cooperate with the pins 237, 238 in providing lost-motion mechanisms in the seventh embodiment of the present invention, Operation of the drums 234, 235, 236 housed in the junction box 230 will be described below. The carburetor valve device 17, the oil pump 18, and the exhaust valve device 15 shown in FIG. 2 have mechanisms (such as torsion springs), combined directly or indirectly therewith, for closing or decelerating the carburetor valve device 17, the oil pump 18, and the exhaust valve device 15 when the corre- spending cables 224, 225, 226 are loosened. FIGS. 15(a) through 15(d) show the junction box' ' shown in FIG. 13 as viewed in the directions indicated by the arrow "a", "b", "c", "d", respectively, when in a fully closed position. In FIG. 15(b), the throttle cable 23 is fully loosened, and an opening reference line L2 for the drum 234 with respect to the throttle cable 23 is angularly spaced 62 clockwise from a Y-axis which is a vertical axis. In FIG. 15(c), the pin 237 mounted on the drum 234 is positioned at a left-hand end (as seen in FIG, 15(c)) of the cam groove 239 in the drum 235, and an opening reference line L3 for the drum 235 is angularly spaced G3 clockwise from the Y-axis. In FIG. 15(d), the pin 238 mounted on the drum 235 is positioned at a left-hand end (as seen in FIG. 15(d)) of the cam groove 241 in the drum 236, and an opening reference line L4 for the drum 236 is angularly spaced 64 clockwise from the Y-axis. At this time, the lost-motion spring 243 is contracted. In FIG. 15(a), the drum 234 is in the same position as shown in FIG, 15(b), and an opening reference line LI for the drum 234 with respect to the carburetor valve cable 224 is angularly spaced θ1 (= G2) clockwise from the Y-axis. FIGS. 16(a) through 16(d) show the junction box shown in FIG, 13 as viewed in the directions indicated by the arrow "a", "b", "c", "d", respectively, when in a fully opened position. In FIG. 16(b), the drum 234 is pulled by the throttle cable 23 and turned 0 clockwise from the opening reference line L2. In FIG. 16(a), the carburetor valve cable 224 connected to the drum 234 is also pulled, opening the carburetor valve. In FIG. 16(c), the drum 235 is turned 0 clockwise from the opening reference line L3 by the pin 237 mounted on the drum 234, pulling the oil pump cable 225 thereby to accelerate the oil pump. In FIG, 16(d), the drum 236 is turned 8 (= 641 + 642) clockwise from the opening reference line L4 by the pin 238 mounted on the drum 235, pulling the exhaust valve cable 22 6 thereby to open the exhaust valve, FIG. 17 shows opening characteristics of the carburetor and exhaust valves operatively connected to the junction box shown in FIG, 13. The graph shown in FIG. 17 has a horizontal axis representing the angular displacement of the drums, and a vertical axis representing the degree of valve opening. The carburetor valve is opened in substantial proportion to the angular displacement of the drum 224. However, the exhaust valve is required to be restricted when the engine is to rotate at low speeds for low output powers, and to remain open when the engine is to rotate at high speeds for high output powers. The exhaust valve is fully opened when the drum 236 is turned 641 {= 30°, for example) , and remains fully open when the drum 236 is turned from 841 t 842. As shown in FIG. 16(d), the exhaust valve is fully opened when the drum 236 is turned 841, and remains fully oper when the drum 236 is turned from 641 to 642 because the lost-motion spring 243 is extended. To return the carburetor valve, the oil pump, and the exhaust valve from the fully open condition shown in FIGS. 16(a) ~ 16(d) to the fully closed condition shown in FIGS. 15(a) - 15(d), the throttle cable 23 shown in FIG. 16(b) is loosened to the position shown in FIG, 15(b). The pins 237, 238 and the cam grooves 239, 241, which serve as lost-motion mechanisms, will be described below , It is assumed that the drum 235 connected to the oil pump cable 225 is held in the position shown in FIG. 16 (c) for some reason. When the throttle cable 23 shown in FIG. 16(b) is loosened at this time, the pin 237 mounted on the drum 234 connected to the carburetor valve cable 224 moves in the cam groove 239 from the left-hand end toward the right-hand end thereof shown in FIG. 16(c). As a result, only the drum 234 returns to the position shown in FIGS. 15(a) and 15(b), without affecting the drum 235. If the drum 236 connected to the exhaust valve cable 226 is held in the position shown in FIG. 16(d), then only the drums 234, 235 return to the positions shown in FIGS. 15(a) - 15(c) when the throttle cable 23 is loosened. Therefore, even if the drum 235 and/or the drum 236 is fixed to the turned position, the valve of the carburetor valve device 17 can be fully closed by the throttle grip 21 for reducing the output power of the engine 11. FIG. 18 shows a modification of the actuating mechanism according to the seventh embodiment described above. According to the modification shown in FIG. 18, a junction box 230' has a case 231 which houses drums 234, 235, 236 ro-tatably mounted on a shaft 232, A long pin 235 is mounted on the drum 234, and the drums 235, 236 have respective arcuate through cam grooves of identical shapes defined therein in which the long pin 235 is slidably received. Since the drums 235, 236 are identical in shape to each other, they can be used in common, and the number of different parts of the actuating mechanism is reduced, FIG. 19 is a rear elevational view of a steering handle and related parts of a scooter which has the junction box 230 shown in FIG. 13 or the junction box 230' shown in FIG. 18. As shown in FIG. 19, a throttle housing 322 disposed adjacent to a throttle grip 321 is accommodated in a handle cover 301, which supports a direction indicator switch 302 and a starter switch 303 near the throttle housing 322, With the junction box 230 in the seventh embodiment being incorporated in the scooter shown in FIG. 19,* since the junction box 230 and the throttle housing 322 can be separated • from each other, the throttle housing 322 can be greatly reduced in size, allowing the direction indicator switch 302 and the starter switch 303 to be positioned in a layout which can easily be designed. In the seventh embodiment, when the throttle grip is returned to loosen the throttle cable for thereby rotating back the drum connected to the carburetor valve cable, the carburetor valve can be restricted irrespective of how the drum connected to the oil pump cable and the drum connected to the exhaust valve cable are operated. Therefore, the carburetor valve can be operated reliably for safety. Since the three drums are separately housed in the junction box, they can independently be replaced or modified in dimensions, and the cost thereof can be reduced. The junction box which houses the three drums for actuating the carburetor valve device, the oil pump, and the exhaust valve device through the respective cables can be positioned remotely from the throttle grip. Consequently, the throttle housing normally disposed adjacent to the throttle grip can be reduced in size, and various switches can be positioned near the throttle housing in a free layout. WE CLAIM: 1. An exhaust valve device comprising a pipe defining a passage therein for passage therethrough of exhaust gases emitted from the internal combustion engine; a shaft rotatably extending transversely through said pipe perpendicularly to the axis of the pipe and having at least one end portion projecting from said pipe; an exhaust valve fixedly mounted on said shaft in said pipe for selectively opening and closing said passage; and a junction box for branching a throttle cable. 2. The device according to claim 1 wherein return means are provided for returning said shaft to angularly move said exhaust valve from the fully open position to the fully closed position. 3. The device according to claim 1, wherein said junction box comprises a case which supports the opposite ends of said shaft disposed therein; a rotor rotatably mounted as a first drum on said shaft, said throttle cable having an end joined to said first drum; second and third drums rotatably mounted on said shaft successively adjacent to said first drum; a first branched cable branched from said throttle cable and connected to said first drum under a tension tending to angularly move said first drum in one direction about said shaft; a second branched cable branched from said throttle cable and connected to said second drum under a tension tending to angularly move said second drum in said one direction about said shaft and a third branched cable branched from said throttle cable and connected to said third drum under a tension tending to angularly move said third drum in said one direction about said shaft; and lost-motion means comprising at least one pin mounted on a side of said first drum: and arcuate through grooves of identical shape defined respectively in said second and third drums, said pin slidably engaging in said arcuate through grooves. 4. The device according to claim 3 wherein the said fost-motion means comprises a first pin mounted on a side of said first drum; a first arcuate groove defined in said second drum, said first pin slidably engaging in said first arcuate groove; a second pin mounted on a side of said drum; and a second arcuate groove defined in said third drum, said second pin slidably engaging in said second arcuate groove. 5. Ail exhaust valve device, substantially as herein described with reference to the accompanying drawings.

Full Text

GOVERNMENT OF INDIA, THE PATENT OFFICE
2nd M.S.O. BUILDING,
234/4, ACHARYA JAGADISH CHANDRA BOSE ROAD
KOLKATTA - 700 020.
COMPLETE SPECIFICATION NO. 1912229 DATED: 18-Sep-OO
APPLIATION NO. 778 MAS 00 DATED: 18-Sep-OO
Divisional to Patent Application No: 1172/MAS/94 Ante-dated to 25th Nov, 1994
ACCEPTANCE OF THE COMPLETE SPECIFICATION ADVERTISED ON 11.10.2003
INDEX AT ACCEPTANCE 107 E , K
INTERNATIONAL CLASSIFICATION"—— F 02 D 13/00
TITLE : "AN EXHAUST VALVE DEVICE"
APPLICANT : HONDA GIKEN KOGYO KABUSHIKI
KAISHA
1-1, MINAMI-A0YAMA2-CH0ME MINATO-KU, TOKYO JAPAN
INVENTORS 1.M1TSU0 KUSA;
2. MAS AS HI YOKOYAMA;
3. KAORU HAYASHI;
4. MIKIO SAGARA.
THE FOLLOWING SPECIFICATION PARTICULARLY DESCIRBES AND ASCERTAINS THE NATURE OF THIS INVENTION AND THE MANNER IN
WHICH IT IS TO BE PERFORMED: -

The present invention relates to a mechanism for actuating a device in an internal combustion engine, and more particularly to a mechanism for actuating an exhaust valve, a carburetor valve, or an oil pump in an internal combustion engine such as a two-cycle engine to completely burn an air-fuel mixture in a combustion chamber while preventing blow-by_ when the engine is operating under a low load, for example.
Heretofore, it has been customary to employ an electric motor for independently controlling the degree of opening of an exhaust valve or an exhaust throttle valve in a two-cycle engine to completely burn an air-fuel mixture in a combustion chamber while preventing blow-by when the engine is operating under a low load.
It has been known to give an exhaust valve predetermined valve opening characteristics with an actuator unit which is disposed in a throttle housing (see Japanese laid-open utility model publication No. 50-153306, for example). This publication discloses a motorcycle having a carburetor valve or a carburetor throttle valve and an exhaust valve. The carburetor valve is actuated by a first wire reel through a wire, and the exhaust valve is actuated by a second wire reel through a wire. These first and second wire reels are housed in a case positioned adjacent to a throttle grip, and can be turned when the throttle grip is turned by the rider of the motorcycle. The case which houses the first and second wire reels is generally referred to as a throttle housing .
According to the above publication, since the second wire reel is moved in unison with the first wire reel that is ganged with the carburetor valve, the first wire reel is subject to the load from the second wire reel at all times. Therefore^ when the first wire reel,is quickly returned, the second wire reel is also rotated in unison with

the first wire reel. Depending on the exhaust pressure acting on the exhaust valve, the second wire reel may adversely affect the returning motion of the first wire reel, i.e., the quick movement of the carburetor valve to its closed position .
In the above publication, the throttle housing is associated with the right-hand grip of the steering handle. The first and second wire reels are positioned as larger- and smaller-diameter reels in the throttle housing, which also houses springs and pins. Consequently, the throttle housing houses a highly complex mechanism. This is because the carburetor valve and the exhaust valve are opened and closed according to different specifications.
Motorcycles, particularly small-size scooters, have small-size steering handles. Because various switches are installed on the steering handles near the throttle grip, it is quite difficult to attach a complex, large-size throttle housing, which accommodates first and second wire reels, to the steering handles.
The conventional arrangement which employs the electric motor for controlling the exhaust valve is complex in structure and highly costly because it requires various extra mechanical and electrical components. According to the structure shown in the above publication, since various components need to be housed in the throttle housing, there is no layout freedom available for the mechanisms in the throttle housing, On scooters, certain limitations are imposed on the layout of components because the throttle housing should be placed in a steering handle cover.
It is therefore an object of the present invent ion to provide a mechanism for actuating a device in an internal combustion engine smoothly with desired characteristics through a simple mechanical arrangement with respect to a throttle opening in response to movement of a throttle cable which is caused by angular movement of a throttle grip, for example, as an accelerator actuating element,

According to the present invention, there is provided a mechanism for actuating a device in an internal combustion engine having a throttle cable, comprising a rotor angularly movable in response to movement of the throttle for actuating the device, and lost-motion means for making the rotor idle in a partial stroke of angular movement thereof in actuating the device.
The device in the internal combustion engine may comprise an exhaust valve device, which comprises a pipe defining a passage therein for passage therethrough of exhaust gases emitted from the internal combustion engine, a shaft rotatably extending transversely through the pipe perpendicularly to the axis of the pipe and having at least one end portion projecting from the pipe, and an exhaust valve fixedly mounted on the shaft in the pipe for selectively opening and closing the passage.
The rotor comprises a drum rotatably fitted over said one end portion of the shaft projecting from the pipe, the throttle cable having an end wound around the drum, the lost-motion means being interposed between the drum and the shaft. The lost-motion means comprises a bracket fixed to said one end portion of the shaft projecting from the pipe, and a spring disposed under compression between the bracket and the drum. The lost-motion means further comprises stopper means for keeping the exhaust valve fully' open after the exhaust valve has been angularly moved from a fully closed position to a fully open position in response to angular movement of the drum. The stopper means comprises a stopper pin mounted on the shaft perpendicularly to the axis thereof for abutment against the pipe in an angular position of the shaft in which the exhaust valve is in the fully open position . The exhaust valve device further comprises return means for returning the shaft to angularly move the exhaust valve from the fully open position to the fully closed position .
The device in the internal combustion engine may

comprise a junction cable in which the throttle cable is branched. The junction box comprises a case, a shaft disposed in the case and having opposite ends supported by the case, the rotor being rotatably mounted as a first drum on the shafts the throttle cable having an end joined to the first drum, second and third drums rotatably mounted on the shaft successively adjacent to the first .drum, a first branched cable branched from the throttle cable and connected to the first drum under a tension tending to angularly move the first drum in one direction about the shaf, a second branched cable branched from the throttle cable and connected to the second drum under a tension tending to angularly move the second drum in said one direction abour the shaft, and a third branched cable branched from the thrcttle cable and connected to "che third drum under a tension cending to angularly move the third drum in said one directicn abcur the shafT: . The losr-moticn means comprises a first pin mounted on a side of the firsu drum, a first arcuate groove defined in the second drum, the first pin slidably engaging in the first arcuate groove, a second pin mounted en a side of the second drum, and a second arcuate groove defined" in the third drum, the second pin slidably engaging in the second arcuate groove. When the first drumi is .angularly moved in a direction opposite to said one direction by the throttle cable, the-first and second pins engage respective ends of the second and third arcuate grooves, respectively, to allow the second and third drums to angularly move in the direction opposite to said one direction, and when the throttle cable is loosened, the first drum is pulled by the first branched cable and turned "in said one direction, and the first and second pins move toward respective opposite ends of the second and third arcuate grooves, respectively, and thereafter engage the respect'ive opposite ends thereof for allowing the second and third drums to angularly move in said one direc-tion.

Accordingly the present invention provides an exhaust valve device comprising a pipe defining a passage therein for passage therethrough of exhaust gases emitted from the internal combustion engine; a shaft rotatably extending transversely through said pipe perpendicularly to the axis of the pipe and having at least one end portion projecting from said pipe; an exhaust valve fixedly mounted on said shaft in said pipe for selectively opening and closing said passage; and a junction box for branching a throttle cable.
The parent application No. 1172/MAS/94 describes and claims a mechanism for actuating a device in an internal combustion engine having a throttle cable.
The invention will now be described in more detail with reference to embodiments shown in the accompanying drawings, in which;
Fig. 1 is a side elevational view of a motorcycle

which incorporates the principles of the present invention;
FIG. 2 is a side elevational view showing how a junction box and related devices are interconnected in the motorcycle shown in FIG. 2;
FIG. 3 is a graph showing opening characteristics of an exhaust valve as required by engine output power;
FIG. 4 is a cross-sectional view of an exhaust valve device incorporating a mechanism for actuating a device in an internal combustion engine according to a first embodiment of the present invention;
FIG. 5 is a side elevational view of the exhaust valve device shown in FIG. 4;
FIG. 6 is a cross-sectional view of the exhaust valve device shown in FIG. 4;
FIG. 7(a) is a partly cross- sectional view showing the manner in which an exhaust valve is fully closed when a throttle cable is loosened in the exhaust valve device shown in FIG. 4;
FIG. 7(b) is a partly cross-sectional view showing the manner in which the exhaust valve is fully opened when the throttle cable is pulled in the exhaust valve device shown in FIG. 4;
FIG. 7(c) is a partly cross-sectional view showing the manner in which the exhaust valve is fully opened, with the throttle cable being shown as further pulled entering a lost-motion condition;
FIG. 8(a) is a fragmentary side elevational view of an exhaust valve device incorporating a mechanism for actuating a device in an internal combustion engine according to a second embodiment of the present invention, the view showing the manner in which an exhaust valve is fully closed;
FIG. 8(b) is a fragmentary side elevational view of the exhaust valve device shown in Fig. 8(a), showing the manner in which the exhaust valve is fully opened when a throt-tie cable is pulled, the throttle cable being shown as further pulled entering a lost-motion condition;

FIG. 9 is a fragmentary side elevational vief, of an exhaust valve device incorporating a mechanism for actuating a device in an internal combustion engine according to a third embodiment of the present invention;
FIG. 10 is a fragmentary side elevational view of an exhaust valve device incorporating a mechanism for actuating a device in an internal combustion engine according to a fourth embodiment of the present invention;
FIG. 11(a) is a fragmentary plan view of an exhaust valve device incorporating a mechanism for actuating a device in an internal combustion engine according to a fifth embodiment of the present invention, the view showing the manner in which an exhaust valve is fully opened;
FIG. 11(b) is a fragmentary plan view of the exhaust valve device shown in FIG. 11 (a), showing the manner in which the exhaust valve is fully opened when a throttle cable is pulled, the throttle cable being shown as further pulled entering a lost-motion condition;
FIG. 12(a) is a fragmentary side elevational view of an exhaust valve device incorporating a mechanism for actuating a device in an internal combustion engine according to a sixth embodiment of the present invention, the view showing the manner in which an exhaust valve is fully closed;
FIG. 12(b) is a fragmentary side elevational view of the exhaust valve device shown in FIG. 12(a), shov;ing the manner in which the exhaust valve is fully opened;
FIG. 13 is a fragmentary cross-sectional view of a junction box incorporating a mechanism for actuating a device in an internal combustion engine according to a seventh embodiment of the present invention;
FIG. 14 is an exploded perspective view of a plurality of adjacent drums disposed in the junction box shown in FIG. 13;
FIG. 15(a) is a view of the junction box shown in FIG. 13 as viewed in the direction indicated by the arrow "a" when in a fully closed position;

FIG. 15(b) is a view of the junction box shown in FIG. 13 as viewed in the direction indicated by the arrow "b" when in a fully closed position;
FIG. 15(c) is a view of the junction box shown in FIG. 13 as viewed in the direction indicated by the arrow "c" when in a fully closed position;
FIG. 15(d) is a view of the junction box shown in FIG. 13 as viewed in the direction indicated by the arrow "d" when in a fully closed position;
FIG. 16(a) is a view of the junction box shown in FIG. 13 as viewed in the direction indicated by the arrow "a" when in a fully opened position;
FIG. 16(b) is a view of the junction box shown in FIG. 13 as viewed in the direction indicated by the arrow "b" when in a fully opened position;
FIG. 16(c) is a view of the junction box shown in FIG. 13 as viewed in the direction indicated by the arrow "c" when in a fully opened position;
FIG. 16(d) is a view of the junction box shown in FIG. 13 as viewed in the direction indicated by the arrow "d" when in a fully opened position;
FIG. 17 a graph showing opening characteristics of carburetor and exhaust valves operatively connected to the junction box shown in FIG. 13;
FIG, 18 is a fragmentary cross-sectional view of a modification of the junction box shown in FIG. 13; and
FIG. 19 is a rear elevational view of a steering handle and related parts of a scooter which has the junction box shown in FIG. 13 or 18.
Preferred embodiments of a mechanism for actuating a device in an internal combustion engine will be described in detail below.
FIG, 1 shows a motorcycle 1 which incorporates the principles of the present invention. As shown in FIG. 1, the motorcycle 1 has a front wheel 2, a front fork 4, a steering handle 5, a head pipe 6, a cowling 1, a body frame (not

shown) disposed in the cowling 7, a rider's seat 8, a swing arm 9, and a rear wheel 10. An internal combustion engine 11 is mounted on the body frame substantially centrally in the motorcycle. The engine 11 has a forwardly inclined cylinder block 12 (see also FIG. 2) from which an exhaust pipe 13 extends rearward. The exhaust pipe 13 has a read end connected through an exhaust throttle valve device or exhaust valve device 15 to an expanded exhaust pipe 14 which is positioned on the right-hand side of the motorcycle and has a rear end connected to a muffler 3. The engine also includes an intake passage having a carburetor throttle valve device or carburetor valve device 17, and an oil pump 18 is positioned near the carburetor valve device 17. A junction box 30 is attached to the body frame directly or through a bracket (not shown).
FIG, 2 shows how the junction box 30 and related devices are interconnected. A throttle cable 23 extends from a throttle housing 22 that is positioned adjacent to a throttle grip 21 (accelerator actuating element) to the junction box 30 in which the throttle cable 23 is branched into three cables. These three cables, which extend from the junction box 30, include a cable 24 for the carburetor valve device 17, a cable 25 for the oil pump 18, and a cable 26 for the exhaust valve device 15. The cable 24 is led to the carburetor valve device 17, the cable 25 to the oil pump 18, and the cable 2 6 to the exhaust valve device 15 for actuating these devices. These cables 24, 25, 26 are actually covered with sheaths, and cannot actually be seen. However, these cables 24, 25, 26 and the sheaths will collectively be referred to as cables .
The exhaust valve device 15 has an exhaust valve which is required to have such opening characteristics (i.e., the relationship between the angular displacement of the throttle grip and the opening of the exhaust valve) that, as shown in FIG, 3, the exhaust valve increases its opening substantially linearly until it is fully opened when the throt-

the grip 21 is turned θa θa = 30 - 50 % of the full angular displacement of the throttle grip 21), and the exhaust valve subsequently remains fully open until the throttle grip 21 is fully angularly moved (a lost-motion condition),
Mechanisms for actuating a device in an internal combustion engine according to first through sixth embodiments of the present invention, which will be described below, have a lost-motion mechanism for achieving such opening characteristics.
FIGS. 4 and 5 show an exhaust valve device 15 incorporating an actuating mechanism according to a first embodiment of the present invention. The exhaust valve device 15 has a pipe 120 defining a passage therein for passage therethrough of exhaust gases emitted from the engine 11, a shaft 121 rotatably extending transversely through the pipe 120 and having opposite end portions projecting from the pipe 120 perpendicularly to the axis of the pipe 120, an exhaust valve 122 fixedly mounted on the shaft 121 in the pipe 120, and a drum or rotor 123 rotatably fitted over one of the projecting end portions of the shaft 121.
The shaft 121 is rotatably supported through bearings 124 in brackets 125, 126 which have ends fitted in the pipe 120. The exhaust valve 122 is a plate valve having a size which is substantially equal to an oblique cross-sectional area of the pipe 120 at an angle θb of 30 degrees, for example, to the axis of the pipe 120, as shown in FIG. 6. The exhaust valve 122 is fixed to the shaft 121 such that it lies at the angle θb to the axis of the pipe 120 when the exhaust valve 122 is fully closed, and cannot be turned in the closing direction,
Over one of the end portions of the shaft 121, there are successively fitted a drum 123 through a bearing 127, and a bracket 128. One end of the branched throttle cable 2 6 is wound around the drum 123. The bracket 128 is fixed to the shaft 121 by a threaded nut 129. A spring 130 for pressing the drum 123 is disposed under compression be-

tween the drum 123 and the bracket 128.
Over the other end portion of the shaft 121, there
is fitted a pair of spaced spring holders 132a, 132b which
support a return spring 131 therebetween around the shaft 121
as returning means for returning the exhaust valve 122 into a
fully closed condition. The return spring 131 has an end en
gaging a spring hook 133 that is fixed to the bracket 126,
and the other end engaging a hook (not shown) on the spring
holder 132a. The spring holders 132a, 132b are fixed to the
shaft 121 by a threaded nut 134. The spring holder 132b is
held against the bracket 12 6,
A stopper pin 135 is fixed to the shaft 121 perpendicular to the axis thereof. When the shaft 121 is turned, the stopper pin 135 can abut against a first edge portion of the bracket 125 (see FIG. 7(a)) or a second edge portion of the bracket 125 (see FIG. 7(b)). When the stopper pin 135 abuts against the first or second edge portion of the bracket 125 in an angular position of the shaft 121 in which the exhaust valve 122 is fully closed or opened, the exhaust valve 223 is held in the fully closed or open position. A washer 136 fitted over the shaft 121 is held against the bracket 125 and retained in place by an E-ring 137 fitted over the shaft 121.
Operation of the actuating mechanism according to the first embodiment will be described below with reference to FIGS, 7(a) through 7(d).
FIG. 7(a) shows the manner in which the exhaust valve 122 is fully closed with the throttle grip 21 is not operated. In this condition, the spring holder 132a fixed to the shaft 121 is turned in the direction indicated by the arrow A under the bias of the return spring 131. The shaft 121 is therefore rotated until the stopper pin 135 fixed to the shaft 131 abuts against the first edge portion of the bracket 125 whereupon the exhaust valve 122 secured to the shaft 121 is fully closed. Even though the exhaust valve 122 is in the fully closed position, there is a slight gap or clearance

left between the inner circumferential surface of the pipe 120 and the outer circumferential edge of the exhaust valve 122.
FIG. 7(b) shows the manner in which the exhaust valve 122 is fully opened when the throttle grip 21 is turned a certain angular displacement (ranging from 30 to 50 % of the full angular displacement), i.e., when the throttle grip 21 is turned θa in FIG. 3. Specifically, the throttle grip 21 is turned a certain angular displacement (ranging from 30 to 5 0 % of the full angular displacement) from the position shown in FIG, 7 (a), pulling the throttle cable 26 in the direction indicated by the arrow B (FIG, 7(b)) against the bias of the return spring 131. Although the drum 123 is rotatably fitted over the shaft 121 through the bearing 127, the drum 123 and the shaft 121 are angularly moved together in a direction opposite to the direction A under the forces of the spring 130. The shaft 121 is angularly moved θb until the stopper pin 135 abuts against the second edge portion of the bracket 125, whereupon the exhaust valve 122 has been turned from the fully closed position to the fully open position,
FIG. 7 (c) shows the manner in which the exhaust valve 122 remains fully open even when the throttle grip 21 is turned the full angular displacement. Specifically, the throttle grip 21 is turned the full angular displacement from the position shown in FIG. 7(b), further pulling the throttle cable 26 in the direction B. The drum 123 then rotates around the shaft 121 against the forces of the spring 130.
During this time, though the throttle cable 26 is further pulled, the throttle valve 122 remains in a lost-motion condition in which it is not operated (the throttle grip 21 is turned from the angular displacement θa to the full angular displacement in FIG. 3) . Therefore, the throttle valve 122 is maintained in the fully open position. Stated otherwise, the angular movement of the drum 123 during this time is idling movement, not affecting the exhaust valve 122,
When the throttle grip 21 is fully returned, the

shaft 121 is turned back under the bias of the return spring 131 to angularly move the exhaust valve 122 from the open position to the closed position. The exhaust valve 122 is not fully closed as shown in FIG. 7(a).
FIGS. 8(a) and 8(b) are fragmentary side eleva-tional views of an exhaust valve device 140 incorporating a mechanism for actuating a device in an internal combustion engine according to a second embodiment of the present invention.
As shown in FIGS. 8(a) and 8(b), the exhaust valve device 140 comprises a pipe 141 defining a passage therein for passage therethrough of exhaust gases emitted from the engine 11, a shaft 142 rotatably extending transversely through the pipe 141 and having opposite end portions projecting from the pipe 141 perpendicularly to the axis of the pipe 141, an exhaust valve 143 fixedly mounted on the shaft 142 in the pipe 141, and a link mechanism 144 engaging one of the projecting ends of the shaft 142,
The link mechanism 144 comprises an arm 145 having one end fixed to the shaft 142 and supporting a pin 146 mounted on the other end thereof, and a guide wing or rotor 148 having a guide slot 247 defined in an end portion thereof and guiding the pin 14 6 and an opposite end portion connected to an end of the throttle cable 26.
The guide wing 148 is angularly movably mounted on an outer surface of the pipe 141 by a shaft 149 which is fixed to the pipe 141 and has an end extending through a substantially central portion of the guide wing 148. The end of the throttle cable 26 is connected to the guide wing 148 by a joint 150 that is coupled to the end of the throttle cable 2 6 and angularly movably fitted over a shaft 151 which is fixed to the opposite end portion of the guide wing 148.
Operation of the actuating mechanism shown in FIGS. 8(a) and 8(b) will be described below.
FIG. 8(a) shov.'s the manner in which the exhaust valve 143 is fully closed;, i.e., lies at an angle G^ to the

axis of the pipe 141. When the throttle grip 21 is then turned to pull the throttle cable 2 6 in the direction indicated by the arrow C, the guide wing 148 is turned about the shaft 14 9 in the direction indicated by the arrow D against the bias of a return spring (not shown) having one end engaging the pipe 141 and the other end engaging the guide wing 148,
Since the pin 146 on the arm 145 fixed to the shaft 142 slidably rides in the guide slot 147 in the guide wing 148, the pin 14 6 moves along the guide slot 147 from an end 147a thereof toward an opposite end 147b thereof, during which time the arm 145 is turned. The shaft 142 is also turned in unison with the arm 145 until the pin 146 reaches a corner 147c of the guide slot 147 between its ends 147a, 147b, whereupon the exhaust valve 143 is fully opened. At this time, the throttle grip 21 has been turned θa in FIG. 3.
When the throttle grip 21 is further turned the full angular displacement, pulling the throttle cable 26 in the direction C, the arm 145 is not turned because the portion of the guide slot 147 extending between the corner 147c and the end 147b is arcuate around the shaft 14 9 and moves loosely around the pin 146. Consequently, the exhaust valve 143 remains fully open regardless of the additional pulling of the throttle cable 26.
Specifically, the guide slot 147 includes a first slot section extending from the end 147a to the corner 147c and spaced progressively farther from the center of the shaft 149, and a second slot section extending contiguously from the corner 147c to the end 147b and spaced a constant distance from the center of the shaft 14 9,
FIG- 8(b) shows the manner in which the exhaust valve 143 is in a lost-motion condition while the throttle grip 21 is being turned from the angular displacement θa to the full angular displacement.
When the throttle grip 21 is turned the full angular displacement, the guide wing 148 is fully nurned in the

direction D about the shaft 14 9, with the end 147b of the guide slot 147 being positioned closely to the pin 14 6.
When the throttle grip 21 is fully returned, the exhaust valve 143 is returned to the fully closed position shown in FIG- 8(a) under the resiliency of the non-illus-trated return spring.
Since the link mechanism 144 serves as a lost-mo-tion mechanism, desired opening characteristics of the exhaust valve 143 can be achieved simply by the configuration of the guide slot 147.
The non-illustrated return spring in the exhaust valve device 140 may comprise a return spring similar to the return spring 131 in the exhaust valve device 15 according to the first embodiment, the return spring being mounted on the end of the shaft 142 opposite to the end thereof which is connected to the arm 145 associated with the guide wing 148.
FIG. 9 shows an exhaust valve device 160 incorporating a mechanism for actuating a device in an internal combustion engine according to a third embodiment of the present invention.
The exhaust valve device 160 comprises a pipe 161 defining a passage therein for passage therethrough of exhaust gases emitted from the engine 11, a shaft 162 rotatably extending transversely through the pipe 161 and having opposite end portions projecting from the pipe 161 perpendicularly to the axis of the pipe 161, an exhaust valve 163 fixedly mounted on the shaft 162 in the pipe 161, and an arm
164 fixed at its center to one of the projecting ends of the
shaft 162.
The arm 164 supports on one end thereof a fixed pin
165 over which there is fitted one end of an attachment 166
connected at the other end thereof to the throttle cable 26.
The other end of the arm 164 can be held in abutment against
a stop 167 mounted on the pipe 161 when the arm 164 is turned
to a certain angular position in which the exhaust valve 163
is fully open. A spring 168 is connected in the throttle ca-

ble 26 in series therewith near the attachment 166.
The actuating mechanism according to the third embodiment operates as follows: FIG. 9 shows the manner in which the exhaust valve 163 is fully closed with the throttle grip 21 not turned. When the throttle grip 21 is turned to pull the throttle cable 26 in the direction indicated by the arrow E, the arm 164 is turned about the shaft 162 in the direction indicated by the arrow F against the bias of a return spring (not shown) which has one end joined to the pipe 161 and the other end to the arm 164, and the shaft 162 is also turned in- unison with the arm 164.
When the other end of the arm 164 abuts against the stop 167, the exhaust valve 163 is fully opened. At this time, the throttle grip 21 is turned θa in FIG. 3, When the throttle grip 21 is further turned the full angular displacement to pull the throttle cable 26 in the direction E, the spring 168 is resiliently stretched. The stretched length of the spring 168 absorbs the stroke of the throttle cable 2 6 after the exhaust valve 163 has been fully opened. The exhaust valve 163 is now in a lost-motion condition in which it is not operated (the throttle grip 21 is turned from the angular displacement θa to the full angular displacement in FIG. 3) regardless of the further pulling of the throttle cable 26. Therefore, the exhaust valve 163 is maintained in the fully open position.
When the throttle grip 21 is fully returned, the exhaust valve 163 is returned to the fully closed position shown in FIG. 9 under the resiliency of the non-illustrated return spring.
The return spring 168 connected in the throttle cable 26 in series therewith serves as a lost-motion mechanism for the exhaust valve 163.
The non-illustrated return spring in the exhaust valve device 160 may be arranged in the sanae manner as the return spring 131 in the exhaust valve device 15 according to the first embodiment.

FIG. 10 shows an exhaust valve device 170 incorporating a mechanism for actuating a device in an internal combustion engine according to a fourth embodiment of the present invention.
The exhaust valve device 170 comprises a pipe 171 defining a passage therein for passage therethrough of exhaust gases emitted from the engine 11, a shaft 172 rotatably extending transversely through the pipe 171 and having opposite end portions projecting from the pipe 171 perpendicularly to the axis of the pipe 171, an exhaust valve 173 fixedly mounted on the shaft 172 in the pipe 171, and an arm 174 fixed at a portion near an end 174a thereof to one of the projecting ends of the shaft 172.
The end 174a of the arm 174 can be brought into abutment against a stop 171 mounted on the pipe 171. The arm 174 has an opposite end portion 174b with a guide slot 176 defined therein. An attachment 178 is connected at one end thereof to the end of the throttle cable 26 and supports on its other end a fixed pin 177 which is slidably fitted in the guide slot 176.
Operation of the actuating mechanism according to the fourth embodiment will be described below. FIG. 10 shows the manner in which the exhaust valve 173 is fully closed with the throttle grip 21 not turned. When the throttle grip 21 is turned to pull the throttle cable 26 in the direction indicated by the arrow G, the arm 174 is turned about the shaft 172 in the direction indicated by the arrow H against the bias of a return spring (not shown) which has one end joined to the pipe 171 and the other end to the arm 174, and the shaft 172 is also turned in unison with the arm 174.
When the end 174a of the arm 174 abuts against the stop 175, the exhaust valve 173 is fully opened. At this time, the throttle grip 21 is turned 8a in FIG. 3.
When the throttle grip 21 is further turned the full angular displacement to pull the throttle cable 26 in the direction G, the pin 177 moves in and along the guide

slot 176 toward an outer end 176a thereof. This movement of the pin 177 absorbs the stroke of the throttle cable 26 after the exhaust valve 163 has been fully opened. The exhaust valve 173 is now in a lost-motion condition in which it is not operated (the throttle grip 21 is turned from the angular displacement θa to the full angular displacement in FIG. 3) regardless of the further pulling of the throttle cable 26. Therefore, the exhaust valve 173 is maintained in the fully open position.
When the throttle grip 21 is fully returned, the exhaust valve 173 is returned to the fully closed position shown in FIG. 10 under the resiliency of the non-illustrated return spring.
The guide slot 176 and the pin 177 jointly serve as a lost-motion mechanism for the exhaust valve 173.
The non-illustrated return spring in the exhaust valve device 170 may be arranged in the same manner as the return spring 131 in the exhaust valve device 15 according to the first embodiment.
FIGS. 11(a) and 11(b) show an exhaust valve device 180 incorporating a mechanism for actuating a device in an internal combustion engine according to a fifth embodiment of the present invention.
The exhaust valve device 180 comprises a pipe 181 defining a passage therein for passage therethrough of exhaust gases emitted from the engine 11, a shaft 182 rotatably extending transversely through the pipe 181 and having opposite end portions projecting from the pipe 181 perpendicularly to the axis of the pipe 181 through respective attachment brackets 182a, 182b mounted on the pipe 181, an exhaust valve 183 fixedly mounted on the shaft 182 in the pipe 181, a drum 185 fitted over one of the end portions projecting from the pipe 181, with one end of the throttle cable 26 being wound around the drum 185, and a spring 186 disposed around the shaft 183 under compression between the attachment bracket 182a and the drum 185. The spring 186 has opposite

ends coupled to the attachment bracket 182a and the drum 185, respectively.
The drum 185 engages the shaft 183 such that the drum 185 axially slides in the direction indicated by the arrow J against the bias of the spring 186 when the throttle cable 26 is subject to a tension greater than a predetermined level in the direction indicated by the arrow I.
The actuating mechanism according to the fifth embodiment operates as follows: FIG. 11(a) shows the manner in which the exhaust valve 184 abuts against a stop (not shown) and is fully open when the throttle grip 21 is turned θa in FIG. 3. When the throttle grip 21 is turned to pull the throttle cable 2 6 in the direction indicated by the arrow I to fully open the exhaust valve 184, the drum 185 is moved in the direction indicated by the arrow J against the bias of the spring 18 6. This movement of the drum 185 absorbs the stroke of the throttle cable 26 after the exhaust valve 184 has been fully opened. The exhaust valve 184 is now in a lost-motion condition in which it is not operated (the throttle grip 21 is turned from the angular displacement θa to the full angular displacement in FIG. 3) regardless of the further pulling of the throttle cable 26. Therefore, the exhaust valve 184 is maintained in the fully open position.
When the throttle grip 21 is fully returned, the exhaust valve 184 is returned to the fully closed position shown in FIG. 10 under the resiliency of the spring 186.
The drum 185 which slides axially when the throttle cable 26 is subject to a tension greater than a predetermined level serves as a lost-motion mechanism for the exhaust valve 184.
FIGS. 12(a) and 12(b) show an exhaust valve device 190 incorporating a mechanism for actuating a device in an internal combustion engine according to a sixth embodiment of the present invention.
The exhaust valve device 190 comprises a pipe 191 defining a passage therein for passage therethrough of ex-

haust gases emitted from the engine 11/ a shaft 192 rotatably extending transversely through the pipe 191 and having opposite end portions projecting from the pipe 191 perpendicularly to the axis of the pipe 191, an exhaust valve 193 fixedly mounted on the shaft 192 in the pipe 191, and a drum 194 fixedly mounted on one of the end portions projecting from the pipe 191.
The drum 194 has a portion around which an end of the throttle cable 26 is wound, and that portion of the drum 194 has a radius, or a radial dimension from the axis of the shaft 192, progressively greater in a direction to fully open the throttle valve 193.
The actuating mechanism according to the sixth embodiment operates as follows: FIG, 12(a) shows the manner in which the exhaust valve 193 is fully closed with the throttle grip 21 not turned. When the throttle grip 21 is turned to pull the throttle cable 26 in the direction indicated by the arrow K, the drum 194 is turned about the shaft 192 in the direction indicated by the arrow L against the bias of a return spring (not shown) having one end engaging the pipe 191 and the other end engaging the drum 194, and the shaft 192 is also turned in unison with the drum 194. When the drum 194 abuts against a stop (not shown), the exhaust valve 193 is fully opened as shown in FIG. 12(b) with the throttle grip 21 turned θa in FIG. 3,
The drum 194 may be replaced with the drum 123 according to the first embodiment or the drum 185 according to the fifth embodiment so as to provide a lost-motion mechanism for absorbing the stroke of the throttle cable 26 after the exhaust valve 193 has been fully opened.
When the throttle grip 21 is fully returned, the exhaust valve 193 is returned to the fully closed position shown in FIG. 12(a) under the resiliency of the non-illustrated return spring.
The load on the throttle grip 21 may be reduced by positioning the center of the portion of the drum 194 which

winds the throttle cable 2 6 therearound and the center of rotation of the drum 194 eccentrically with respect to each other.
The non-illustrated return spring in the exhaust valve device 190 may be arranged in the same manner as the return spring 131 in the exhaust valve device 15 according to the first embodiment.
In each of the above embodiments, it is necessary to vary the relationship (opening characteristics) between the angular displacement of the throttle grip and the degree of opening of the exhaust'valve depending on the engine type and the engine output power, and such a requirement can be met by a relatively simple and inexpensive actuating mechanism.
Since the actuating mechanism is incorporated in and around the exhaust valve in each of the above embodiments, it is possible to employ existing parts including the throttle cable 26, the throttle housing 22, etc. in combination with the actuating mechanism.
A mechanism for actuating a device in an internal combustion engine according to a seventh embodiment of the present invention, and a modification thereof will be described below. In the first through sixth embodiments described above, the actuating mechanism is primarily combined directly with the exhaust valve mechanism. In the seventh embodiment, however, the actuating mechanism can be combined with the carburetor valve device and the oil pump as well as the exhaust valve mechanism, and is incorporated in the junction box from which the branched throttle cables extend, as shown in FIGS. 1 and 2.
FIG. 13 shows in cross section a junction box 230 incorporating a mechanism for actuating a device in an inter nal combustion engine according to a seventh embodiment of the present invention. The junction box 230 comprises a case 231, a shaft 232 disposed in the case 231 and having opposite ends supported respectively by side walls of the case 231,

' and a plurality of adjacent drums 234, 235, 236 rotatably mounted on the shaft 232 through journal or roller bearings
233, the drums 234, 235, 236 being coupled respectively to a carburetor valve cable 224, an oil pump cable 225, and an exhaust valve cable 226. The drums 234, 235, 236 on the shaft 232 are separate from each other. Pins 237, 238 are mounted on respective sides of the drums 234, 235, and slidably housed in arcuate cam grooves 239, 241, respectively, which are defined in sides of the drums 235, 236. A spring 242 is disposed under compression between one of the side wall of the- case 231 and the drum 236 for normally urging the drums
234, 235, 236 axially in one direction to eliminate unwanted axial play between the drums 234, 235, 236.
FIG. 14 illustrates the drums 234, 235, 236 in exploded perspective. The carburetor valve cable 224 is attached at one end thereof to the drum 234 on one axial side thereof, and the throttle cable 23 is attached at one end thereof to the drum 234 on the other axial side thereof. The oil pump cable 225 and the exhaust valve cable 22 6 are attached respectively to the drums 235, 236. The cables 224, 225, 226 are longitudinally tensioned to turn the respective drums 234, 235, 236 about the shaft 232 in the directions indicated by the arrows in FIG. 14. A lost-motion spring 243 (described later on) is connected in the exhaust valve cable 226 in series therewith.
The cam grooves 239, 241 are in the form of arcuate grooves, and cooperate with the pins 237, 238 in providing lost-motion mechanisms in the seventh embodiment of the present invention,
Operation of the drums 234, 235, 236 housed in the junction box 230 will be described below. The carburetor valve device 17, the oil pump 18, and the exhaust valve device 15 shown in FIG. 2 have mechanisms (such as torsion springs), combined directly or indirectly therewith, for closing or decelerating the carburetor valve device 17, the oil pump 18, and the exhaust valve device 15 when the corre-

spending cables 224, 225, 226 are loosened.
FIGS. 15(a) through 15(d) show the junction box' ' shown in FIG. 13 as viewed in the directions indicated by the arrow "a", "b", "c", "d", respectively, when in a fully closed position.
In FIG. 15(b), the throttle cable 23 is fully loosened, and an opening reference line L2 for the drum 234 with respect to the throttle cable 23 is angularly spaced 62 clockwise from a Y-axis which is a vertical axis.
In FIG. 15(c), the pin 237 mounted on the drum 234 is positioned at a left-hand end (as seen in FIG, 15(c)) of the cam groove 239 in the drum 235, and an opening reference line L3 for the drum 235 is angularly spaced G3 clockwise from the Y-axis.
In FIG. 15(d), the pin 238 mounted on the drum 235 is positioned at a left-hand end (as seen in FIG. 15(d)) of the cam groove 241 in the drum 236, and an opening reference line L4 for the drum 236 is angularly spaced 64 clockwise from the Y-axis. At this time, the lost-motion spring 243 is contracted.
In FIG. 15(a), the drum 234 is in the same position as shown in FIG, 15(b), and an opening reference line LI for the drum 234 with respect to the carburetor valve cable 224 is angularly spaced θ1 (= G2) clockwise from the Y-axis.
FIGS. 16(a) through 16(d) show the junction box shown in FIG, 13 as viewed in the directions indicated by the arrow "a", "b", "c", "d", respectively, when in a fully opened position.
In FIG. 16(b), the drum 234 is pulled by the throttle cable 23 and turned 0 clockwise from the opening reference line L2.
In FIG. 16(a), the carburetor valve cable 224 connected to the drum 234 is also pulled, opening the carburetor valve.
In FIG. 16(c), the drum 235 is turned 0 clockwise from the opening reference line L3 by the pin 237 mounted on

the drum 234, pulling the oil pump cable 225 thereby to accelerate the oil pump.
In FIG, 16(d), the drum 236 is turned 8 (= 641 + 642) clockwise from the opening reference line L4 by the pin 238 mounted on the drum 235, pulling the exhaust valve cable 22 6 thereby to open the exhaust valve,
FIG. 17 shows opening characteristics of the carburetor and exhaust valves operatively connected to the junction box shown in FIG, 13. The graph shown in FIG. 17 has a horizontal axis representing the angular displacement of the drums, and a vertical axis representing the degree of valve opening.
The carburetor valve is opened in substantial proportion to the angular displacement of the drum 224. However, the exhaust valve is required to be restricted when the engine is to rotate at low speeds for low output powers, and to remain open when the engine is to rotate at high speeds for high output powers. The exhaust valve is fully opened when the drum 236 is turned 641 {= 30°, for example) , and remains fully open when the drum 236 is turned from 841 t 842.
As shown in FIG. 16(d), the exhaust valve is fully opened when the drum 236 is turned 841, and remains fully oper when the drum 236 is turned from 641 to 642 because the lost-motion spring 243 is extended.
To return the carburetor valve, the oil pump, and the exhaust valve from the fully open condition shown in FIGS. 16(a) ~ 16(d) to the fully closed condition shown in FIGS. 15(a) - 15(d), the throttle cable 23 shown in FIG. 16(b) is loosened to the position shown in FIG, 15(b).
The pins 237, 238 and the cam grooves 239, 241, which serve as lost-motion mechanisms, will be described below ,
It is assumed that the drum 235 connected to the oil pump cable 225 is held in the position shown in FIG. 16 (c) for some reason.

When the throttle cable 23 shown in FIG. 16(b) is loosened at this time, the pin 237 mounted on the drum 234 connected to the carburetor valve cable 224 moves in the cam groove 239 from the left-hand end toward the right-hand end thereof shown in FIG. 16(c). As a result, only the drum 234 returns to the position shown in FIGS. 15(a) and 15(b), without affecting the drum 235.
If the drum 236 connected to the exhaust valve cable 226 is held in the position shown in FIG. 16(d), then only the drums 234, 235 return to the positions shown in FIGS. 15(a) - 15(c) when the throttle cable 23 is loosened.
Therefore, even if the drum 235 and/or the drum 236 is fixed to the turned position, the valve of the carburetor valve device 17 can be fully closed by the throttle grip 21 for reducing the output power of the engine 11.
FIG. 18 shows a modification of the actuating mechanism according to the seventh embodiment described above. According to the modification shown in FIG. 18, a junction box 230' has a case 231 which houses drums 234, 235, 236 ro-tatably mounted on a shaft 232, A long pin 235 is mounted on the drum 234, and the drums 235, 236 have respective arcuate through cam grooves of identical shapes defined therein in which the long pin 235 is slidably received. Since the drums 235, 236 are identical in shape to each other, they can be used in common, and the number of different parts of the actuating mechanism is reduced,
FIG. 19 is a rear elevational view of a steering handle and related parts of a scooter which has the junction box 230 shown in FIG. 13 or the junction box 230' shown in FIG. 18. As shown in FIG. 19, a throttle housing 322 disposed adjacent to a throttle grip 321 is accommodated in a handle cover 301, which supports a direction indicator switch 302 and a starter switch 303 near the throttle housing 322, With the junction box 230 in the seventh embodiment being incorporated in the scooter shown in FIG. 19,* since the junction box 230 and the throttle housing 322 can be separated

• from each other, the throttle housing 322 can be greatly reduced in size, allowing the direction indicator switch 302 and the starter switch 303 to be positioned in a layout which can easily be designed.
In the seventh embodiment, when the throttle grip is returned to loosen the throttle cable for thereby rotating back the drum connected to the carburetor valve cable, the carburetor valve can be restricted irrespective of how the drum connected to the oil pump cable and the drum connected to the exhaust valve cable are operated. Therefore, the carburetor valve can be operated reliably for safety. Since the three drums are separately housed in the junction box, they can independently be replaced or modified in dimensions, and the cost thereof can be reduced.
The junction box which houses the three drums for actuating the carburetor valve device, the oil pump, and the exhaust valve device through the respective cables can be positioned remotely from the throttle grip. Consequently, the throttle housing normally disposed adjacent to the throttle grip can be reduced in size, and various switches can be positioned near the throttle housing in a free layout.

WE CLAIM:
1. An exhaust valve device comprising a pipe defining a passage therein for passage therethrough of exhaust gases emitted from the internal combustion engine; a shaft rotatably extending transversely through said pipe perpendicularly to the axis of the pipe and having at least one end portion projecting from said pipe; an exhaust valve fixedly mounted on said shaft in said pipe for selectively opening and closing said passage; and a junction box for branching a throttle cable.
2. The device according to claim 1 wherein return means are provided for returning said shaft to angularly move said exhaust valve from the fully open position to the fully closed position.
3. The device according to claim 1, wherein said junction box comprises a case which supports the opposite ends of said shaft disposed therein; a rotor rotatably mounted as a first drum on said shaft, said throttle cable having an end joined to said first drum; second and third drums rotatably mounted on said shaft successively adjacent to said first drum; a first branched cable branched from said throttle cable and connected to said first drum under a tension tending to angularly move said first drum in one direction about said shaft; a second branched cable branched from said throttle cable and connected to said second drum under a tension tending to angularly move said second drum in said one direction about said shaft and a

third branched cable branched from said throttle cable and connected to said third drum under a tension tending to angularly move said third drum in said one direction about said shaft; and lost-motion means comprising at least one pin mounted on a side of said first drum: and arcuate through grooves of identical shape defined respectively in said second and third drums, said pin slidably engaging in said arcuate through grooves.
4. The device according to claim 3 wherein the said fost-motion
means comprises a first pin mounted on a side of said first drum; a first
arcuate groove defined in said second drum, said first pin slidably engaging
in said first arcuate groove; a second pin mounted on a side of said drum;
and a second arcuate groove defined in said third drum, said second pin
slidably engaging in said second arcuate groove.
5. Ail exhaust valve device, substantially as herein described with
reference to the accompanying drawings.

Documents:

778-mas-2000-abstract.pdf

778-mas-2000-claims filed.pdf

778-mas-2000-claims granted.pdf

778-mas-2000-correspondnece-others.pdf

778-mas-2000-correspondnece-po.pdf

778-mas-2000-description(complete) filed.pdf

778-mas-2000-description(complete) granted.pdf

778-mas-2000-drawings.pdf

778-mas-2000-form 1.pdf

778-mas-2000-form 26.pdf

778-mas-2000-form 3.pdf

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Patent Number

191229

Indian Patent Application Number

778/MAS/2000

PG Journal Number

36/2010

Publication Date

03-Sep-2010

Grant Date

Date of Filing

18-Sep-2000

Name of Patentee

HONDA GIKEN KOGYO KABUSHIKI KAISHA

Applicant Address

1-1, MINAMI-AOYAMA 2-CHOME MINATO-KU, TOKYO

Inventors:

#	Inventor's Name	Inventor's Address
1	MITSUO KUSA	HONDA R&D CO LTD 4-1, CHUO 1-CHOME WAKO-SHI, SAITAMA
2	MASASHI YOKOYAMA	HONDA R&D CO LTD 4-1, CHUO 1-CHOME WAKO-SHI, SAITAMA
3	KAORU HAYASHI	HONDA R&D CO LTD 4-1, CHUO 1-CHOME WAKO-SHI, SAITAMA
4	MIKIO SAGARA	HONDA R&D CO LTD 4-1, CHUO 1-CHOME WAKO-SHI, SAITAMA

PCT International Classification Number

F02D 13/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA