Title of Invention

"MOTORCYCLE"

Abstract A motorcycle comprising a radiator (162) and a thermostat (175) that are arranged on one side of an engine body (30) having a cooling water jacket (158) and mounted to a body frame (21), the thermostat (175) controlling a flow rate at which cooling water discharged from the cooling water jacket (158) flows into the radiator (162), wherein the thermostat is arranged along the body frame (21) at the middle of the radiator core (165) as viewed in the front-rear direction of the motorcycle, and the radiator (162) and thermostat (175) are covered by a common radiator cover (168) from an outer side.
Full Text [Document Name] Specification [Title of the Invention] Motorcycle [Technical Field] [0001]
The present invention relates to a motorcycle having a radiator and a thermostat that are arranged on one side of the engine body having a cooling water jacket and mounted to the body frame, the thermostat controlling the flow rate at which cooling water discharged from the cooling water jacket flows into the radiator. [Background Art] [0002]
A motorcycle of this type is already known, as disclosed in Patent Document 1, for example. [Patent Document 1] JP-A No. 2003-170792 [Disclosure of the Invention] [Problem to be Solved by the Invention] [0003]
However, in the motorcycle disclosed in Patent Document 1 mentioned above, the radiator is covered by a radiator cover from the outer side, and the thermostat is covered by a thermostat cover from the outer side, thus leading to an increase in the number of parts as well as the number of assembly man-hours. [0004]
The present invention has been made in view of the above-mentioned problem, and accordingly it is an object of the present invention to provide a motorcycle in which a radiator and a thermostat are covered from the outer side while enabling a

reduction in the number of parts and the number of assembly man-hours .
[Means for Solving the Problem] [0005]
In order to achieve the above-mentioned object, according to an aspect of the invention in Claim I, there is provided a motorcycle including a radiator and a thermostat that are arranged on one side of an engine body having a cooling water jacket and mounted to a body frame, the thermostat controlling a flow rate at which cooling water discharged from the cooling water jacket flows into the radiator, wherein the radiator and the thermostat, which is arranged along a width direction of the body frame at substantially the same position as a radiator core equipped to the radiator, are covered by a common radiator cover from an outer side. [0006]
According to an aspect of the invention in Claim 2, in addition to the aspect of the invention in Claim 1, an exhaust pipe connected to a cylinder head of the engine body is extended rearward while passing below the engine body, and an exhaust pipe cover portion covering at least a part of the exhaust pipe from an outer side is integrally provided to the radiator cover. [0007]
According to an aspect of the invention in Claim 3, in addition to the aspect of the invention in Claim 1 or 2, the thermostat is attached to a pump housing of a cooling water pump that is attached to the engine body. [Effect of the Invention]

[0008]
According to the aspect of the invention in Claim 1, the radiator core of the radiator and the thermostat are arranged at the same position along the width direction of the body frame, and the radiator and the thermostat are covered by the common radiator cover from the outer side, whereby the number of parts and the number of assembly man-hours can be reduced in covering the radiator and the thermostat from the outer side. [0009]
According to the aspect of the invention in Claim 2, in addition to the radiator and the thermostat, at least a part of the exhaust pipe below the engine body is covered by the radiator cover, whereby a further reduction can be achieved in the number of parts. [0010]
According to the aspect of the invention in Claim 3, the cooling water pump is attached to the engine body, and the thermostat is attached to the pump housing of the cooling water pump. Accordingly, the cooling water pump can be arranged while effectively using the space between the thermostat, which is located at substantially the same position as the radiator core along the width direction of the body frame, and the engine body, thereby making it possible to realize compact construction around the engine.
[Best Mode for Carrying Out the Invention] [0011]
An embodiment mode of the present invention will be described below by way of an embodiment of the present invention

shown in the accompanying drawings.
[0012]
[Brief Description of the Drawings]
[0068]
[Fig. 1] is a side view of a scooter type vehicle.
[Fig. 2] is an enlarged main-portion view of Fig. 1.
[Fig. 3] is a sectional view taken along the line 3-3 of Fig. 2.
[Fig. 4] is an enlarged main-portion view of Fig. 2.
[Fig. 5] is a side view corresponding to Fig. 4, showing a state with a radiator cover detached.
[Fig. 6] is a perspective view of an exhaust emission purifier.
[Fig. 7] is a view as seen from the arrow 7 of Fig. 4.
[Fig. 8] is an enlarged cross-sectional view showing the vicinity of a driven pulley of a continuously variable transmission.
[Fig. 9] is an enlarged left side view of an air cleaner.
[Fig. 10] is a view as seen from the arrow 10 of Fig. 9.
[Fig. 11] is an enlarged sectional view taken along the line 11-11 of Fig. 9.
[Fig. 12] is a sectional view taken along the line 12-12 of Fig. 11.
[Fig. 13] is a sectional view taken along the line 13-13 of Fig. 4.
[Fig. 14] is a sectional view of an engine body taken along the line 14-14 of Fig. 5, depicting a radiator in an upright

position to illustrate a water circulation path.
[Fig. 15] is a partial cutaway side view of a fan cover as seen in the direction of the arrow line 15-15 of Fig. 13.
[Fig. 16] is a view as seen from the arrow 16 of Fig. 15. [0012]
Figs. 1 to 16 show an embodiment of the present invention. Fig. 1 is a side view of a scooter type vehicle, Fig. 2 is an enlarged main-portion view of Fig. 1, Fig. 3 is a sectional view taken along the line 3-3 of Fig. 2, Fig. 4 is an enlarged main-portion view of Fig. 2, Fig. 5 is a side view corresponding to Fig. 4, showing a state with a radiator cover detached, Fig. 6 is a perspective view of an exhaust emission purifier, Fig. 7 is a view as seen from the arrow 7 of Fig. 4, Fig. 8 is an enlarged cross-sectional view showing the vicinity of a driven pulley of a continuously variable transmission, Fig. 9 is an enlarged left side view of an air cleaner, Fig. 10 is a view as seen from the arrow 10 of Fig. 9, Fig. 11 is an enlarged sectional view taken along the line 11-11 of Fig. 9, Fig. 12 is a sectional view taken along the line 12-12 of Fig. 11, Fig. 13 is a sectional view taken along the line 13-13 of Fig. 4, Fig. 14 is a sectional view of an engine body taken along the line 14-14 of Fig. 5, depicting a radiator in an upright position to illustrate a water circulation path, Fig. 15 is a partial cutaway side view of a fan cover as seen in the direction of the arrow line 15-15 of Fig. 13, and Fig. 16 is a view as seen from the arrow 16 of Fig. 15. [0013]
It should be noted that in the following description, the terms "front/rear" and "left/right" are defined with reference to the travel direction of the scooter type vehicle. [0014]
First, in Fig. 1, a body frame 21 of the scooter type


vehicle that is a motorcycle includes a front frame 22 supporting a step floor 26 and extending downwardly forward from a head pipe 25, which steerably supports a front fork 24 journalling a front wheel WF, and a rear frame 23 extending upwardly rearward from a rear portion of the front frame 22 and supporting an occupant seat 27. A power unit P, which journalls a rear wheel WR and drives the rear wheel WR, is suspended from the body frame 21 via a suspension link 28 so as to be vertically rockable. A rear cushion 29 that provides cushioning against the vertical rocking motion of the power unit P is provided between the rear frame 23 and the power unit P. [0015]
In Figs. 2 and 3, an engine body 30 of an engine E of the power unit P includes a crankcase 31, a cylinder block 32 joined to the front end of the crankcase 31 in a forward tilting position, and a cylinder head 33 joined to the front end of the cylinder block 32. [0016]
A crankshaft 35 having a laterally extending axis is rotatably supported on the crankcase 31. A piston 37, which is slidably fit in a cylinder bore 36 provided in the cylinder block 32, is connected to the crankshaft 35 via a connecting rod 38 and a crankpin 39. An ignition plug 40 is attached to the cylinder head 33, and a valve system 41 equipped with a camshaft 65 with decompression means 34 attached thereto is disposed, with a head cover 42 covering the valve system 41 being joined to the front end of the cylinder head 33. [0017]

The crankcase 31 is formed by joining together left-side and right-side case halves 31L, 31R that are split to the left and right along a vertical plane including the axis of the cylinder bore 36. The crankshaft 35 rotatably penetrates the left-side and right-side case halves 31L, 31R, and ball bearings 43, 44 are interposed between the two case halves 31L, 31R and the crankshaft 35, respectively. [0018]
Referring also to Figs. 4 and 5, an air cleaner 45 is arranged above the power unit P. The air cleaner 45 is connected via a carburetor 47 and an intake pipe 48 to an intake port 46 (see Fig. 14) provided in an upper side surface of the cylinder head 33. Further, an exhaust port 49 is provided in a lower side surface of the cylinder head 33. An exhaust pipe 50 whose upstream end is connected to the exhaust port 49 extends downward from the cylinder head 33 and is extended rearward while passing below the front portion of the power unit P. The downstream end of the exhaust pipe 50 is connected to an exhaust muffler 51 arranged to the right side of the rear wheel WR. [0019]
Referring also to Fig. 6, the exhaust gas discharged from the exhaust port 49 is purified by an exhaust emission purifier 54 for introducing secondary air into exhaust gas. The exhaust emission purifier 54 includes a resonator 56 having a forwardly open suction pipe 55 and supported on the rear frame 23, a secondary-air cleaner 58 that is connected to a midway position of the suction pipe 55 via a duct 57, a secondary-air control valve 59 connected to the secondary-air cleaner 58 so as to

control the air flow rate in accordance with the intake negative pressure, a reed valve 60 connected to the secondary-air control valve 59 so as to permit passage of flow only from the secondary-air control valve 59 side, and a hose 61 made of rubber whose upstream end is connected to the reed valve 60 so as to introduce air from the reed valve 60, and a connecting pipe 62 made of metal whose upstream end is connected to the hose 61. The intake pipe 48 is connected to a negative pressure extraction duct 63 for introducing intake negative pressure to the secondary-air control valve 59. [0020]
In Fig. 7, the downstream end of the connecting pipe 62 is connected to the cylinder head 33 so as to communicate with a passage 69 that is provided in the cylinder head 33 so as to communicate with the exhaust port 49. Furthermore, a U-shaped portion 62a that is bent in a substantially U-shaped configuration is formed in a part of the connecting pipe 62. As seen in side view, the U-shaped portion 62a is arranged between a lower side surface of the cylinder head 33 and the exhaust pipe 50. Furthermore, as illustrated in Fig. 7, the U-shaped portion 62a is arranged so that a part of the U-shaped portion 62a is located between the lower side surface of the cylinder head 33 and the exhaust pipe 50. [0021]
Referring to Fig. 3 again, on the outside of the ball bearing 43 interposed between the left-side case half 31L and the crankshaft 35 in the crankcase 31, a drive sprocket 64 is fixed onto the crankshaft 35. A driven sprocket 66 is fixed onto the

camshaft 65 equipped to the valve system 41, and an endless timing chain 67 is wound around the drive sprocket 64 and the driven sprocket 66. A chain passage 68 for allowing the travel of the timing chain 67 is provided in the left-side case half 31L, the cylinder block 32, and the cylinder head 33. [0022]
Further, a power transmission case 71 accommodating a power transmission system T that constitutes the power unit P in cooperation with the engine E is connected to the left-side case half 31L so as to be extended to the left side of the rear wheel WR. [0023]
The power transmission case 71 is composed of an inner case 72, an outer case 73, and a reduction gear case 74. The inner case 72 is provided integrally with the left-side case half 31L of the crankcase 31 so as to overhang from the outer surface of the cylinder block 32 along the axis of the crankshaft 35 and extend rearward. The outer case 73 is joined to the inner case 72 from the left side, and the reduction gear case 74 is joined to the right-side rear portion of the inner case 72. A transmission chamber 75 as a dry space is formed between the inner case 72 and the outer case 73. A speed reducer chamber 76 separated apart from the transmission chamber 75 is formed between the inner case 72 and the reduction gear case 74 so as to store oil therein. An axle 77 of the rear wheel WR is rotatably supported on the rear portion of the inner case 72 and the reduction gear case 74 in the power transmission case 71. [0024]

The power transmission system T includes a V-belt type continuously variable transmission 78 accommodated in the transmission chamber 75, and a gear reducer mechanism 79 provided between the continuously variable transmission 78 and the axle 77 and accommodated in the speed reducer chamber 76. [0025]
On the outside of the drive sprocket 64, the crankshaft 35 penetrates the left-side case half 31L in a fluid-tight and rotatable manner and projects into the transmission chamber 75. The continuously variable transmission 78 includes a drive pulley 80 mounted to one end portion of the crankshaft 35 inside the transmission chamber 75, a driven pulley 83 mounted to a driven shaft 81, which has an axis parallel to the crankshaft 35 and is rotatably supported on the power transmission case 71, via a centrifugal clutch 82, and an endless V-belt 84 that is wound around the drive pulley 80 and the driven pulley 83. [0026]
The drive pulley 80 is composed of a stationary pulley half 85 fixed to one end side of the crankshaft 35, and a movable pulley half 86 located axially inward with respect to the stationary pulley half 85 and mounted to the crankshaft 35 in an axially slidable manner. The V-belt 84 is wound on a V-shaped annular groove 87 formed between the two pulley halves 85, 86. Further, on the back surface side of the movable pulley half 86, a ramp plate 88 is secured onto the crankshaft 35, with a plurality of weight rollers 89 being received in a floating fashion between the movable pulley half 86 and the ramp plate 88. As the rotational speed of the crankshaft 35 increases, the

weight rollers 89 on which the centrifugal force acts move outward in the radial direction of the crankshaft 35, thus bringing the movable pulley half 86 closer to the stationary pulley half 85. This increases the radius of contact of the two pulley halves 85, 86 with the V-belt 84. [0027]
The driven shaft 81 penetrates the inner case 72 in a fluid-tight and rotatable manner. One end portion of the driven shaft 81 is rotatably supported on the outer case 73 via a ball bearing 90, the other end portion of the driven shaft 81 is rotatably supported on the reduction gear case 74 via a ball bearing 91, and the intermediate portion of the driven shaft 81 is rotatably supported on the inner case 72 via a ball bearing 92. [0028]
In Fig. 8, a cylindrical bush 93 is mounted to one end portion of the driven shaft 81. The bush 93 is formed of porous sintered metal and impregnated with oil. Further, the bush 93 is press-fitted into an inner race 90a of the ball bearing 90, and an outer race 90b of the ball bearing 90 is fitted and fixed onto a bearing housing 73a provided in the outer case 73. [0029]
On the other hand, the driven pulley 83 includes an inner cylinder 96 that coaxially surrounds the driven shaft 81 so as to allow relative rotation, an outer cylinder 97 in which the inner cylinder 96 is fitted so as to allow relative pivotal movement about the axis and relative movement in the axial direction, a stationary pulley half 98 fixed to the inner cylinder 96, a movable pulley half 99 fixed to the outer cylinder 97 so as to be

opposed to the stationary pulley half 98, a torque cam mechanism 100 provided between the inner cylinder 96 and the outer cylinder 97 so that an axial component force acts between the two pulley halves 98, 99 in accordance with the difference in relative rotation phase between the movable pulley half 99 and the stationary pulley half 98, and a coil spring 101 for elastically urging the movable pulley half 99 toward the stationary pulley half 98 side. The V-belt 84 is wound on a V-shaped annular groove 102 formed between the stationary pulley half 98 and the movable pulley half 99. Further, the centrifugal clutch 84, which is brought into the power transmission state as the engine rotational speed exceeds a set rotational speed, is provided between the inner cylinder 96 and the driven shaft 81.
[0030]
The distance between the stationary pulley half 98 and the movable pulley half 99 in the driven pulley 83 is determined by the balance between the axial component force generated by the torque cam mechanism 100, the axial elastic force generated by the coil spring 101, and the force from the V-belt 84 acting in the direction for moving the stationary pulley half 98 and the movable pulley half 99 away from each other. As the winding radius of the V-belt 84 on the drive pulley 80 increases by bringing the movable pulley half 86 closer to the stationary pulley half 85 in the drive pulley 80, the winding radius of the V-belt 84 on the driven pulley 83 decreases.
r nrm i

driven shaft 81, a second gear 104 that is in meshing engagement with the first gear 103 and provided to an intermediate shaft 107, which is rotatably supported on the inner case 72 and the reduction gear case 74 so as to be in parallel to the driven shaft 81 and the axle 77, a third gear 105 provided to the intermediate shaft 107, and a fourth gear 106 that is in meshing engagement with the third gear 105 and provided to the axle 77. [0032]
A kick shaft 108 is rotatably supported on the outer case 73 in the power transmission case 71, with a kick pedal (not shown) being provided at the outer end of the kick shaft 108. Further, provided on the inner surface side of the outer case 73 and between the kick shaft 108 and the crankshaft 35 is a kick type starter 109 that enables transmission of the power of the kick shaft 108 to the crankshaft 35 in accordance with the stepping operation on the kick pedal. [0033]
A plurality of radially arranged fins 110 project from the outer surface of the stationary pulley half 85 in the drive pulley 80, so the stationary pulley half 85 also functions as an air blower fan. On the other hand, a connecting pipe portion 111 is provided in the front portion of the outer case 73. A duct (not shown) connected to the connecting pipe portion 111 is extended upward from the connecting pipe portion 111. Thus, as the stationary pulley half 85 functioning as the air blower fan rotates, air in the transmission chamber 75 is discharged to the outside via the connecting pipe portion 111 and the duct. [0034]

Oil in which the first to fourth gears 103 to 106 constituting the gear reducer mechanism 79 are partially immersed to effect lubrication is stored in a lower portion of the speed reducer chamber 76 formed in the power transmission case 71 and accommodating the gear reducer mechanism 79. A delivery pipe portion 113, which is communicated with an upper portion in the speed reducer chamber 76 so as to allow breather gas to be discharged to the outside during thermal expansion of gas in the speed reducer chamber 76 due to an increase in oil temperature, is provided to an upper portion of the gear reducer case 74 in the power transmission case 71, and one end of a breather tube 114 is connected to the delivery pipe portion 113. That is, one end of the breather tube 114 is communicated with an upper portion in the speed reducer chamber 76 and connected to the gear reducer case 74 . [0035]
The breather tube 114 is extended toward the front side of the body frame 21 while being slightly tilted forwardly upward along an upper portion of the power transmission case 71. A clamp member 115 for retaining the intermediate portion of the breather tube 114 is attached to the upper portion of the power transmission case 71. Further, the other end of the breather tube 114 rises upward at the portion corresponding to the air cleaner 45 so as to be upwardly open. [0036]
In Figs. 9 and 10, a cleaner case 116 of the air cleaner 45 is composed of a front case member 117 and a rear case member 118, which are joined to each other so that their joining surface lies

along the width direction of the body frame 21, and a cover member 119 joined to the right side of each of the front and rear case members 117, 118. An element supporting frame 121 retaining a cleaner element 120, which separates the interior of the cleaner case 116 into a purified chamber and an unpurified chamber, is sandwiched between the front and rear case members 117, 118. [0037]
Further, a suction chamber 122 is formed between the front and rear case members 117, 118 and the cover member 119. The front end of the suction chamber 122 serves as a suction port 122a that is forwardly open. Further, a duct 123 that communicates the rear portion of the suction chamber 122 with the unpurified chamber is attached to the side wall of the rear case member 118 on the cover member 119 side. The upstream end of a connecting pipe 124, which is connected to the carburetor 47, projects into the purified chamber. [0038]
Referring also to Figs. 11 and 12, the cover member 119 in the cleaner case 116 has a breather outlet cover 119a integrally provided therein so as to surround the other end portion of the breather tube 114 form the outer side. The other end portion of the breather tube 114 is retained on the breather outlet cover 119a. [0039]
That is, a retention tube portion 125 having a rectangular cross-sectional shape and whose upper end is closed is integrally provided on the inner surface of the breather outlet cover 119a

so as to extend vertically. The other end portion of the breather tube 114 is inserted into the retention tube portion 125. Further, the inner surface of the retention tube portion 125 is provided with four protrusions 126 that are brought into elastic contact with four locations on the outer surface of the breather tube 114 which are circumferentially spaced apart at equal intervals. By inserting the other end portion of the breather tube 114 into the retention tube portion 125, the other end portion of the breather tube 114 is elastically retained in place. Further, a support wall portion 128 connected to the retention tube portion 125 is provided with a substantially U-shaped retention groove 127 through which the breather tube 114 is inserted for retention at a portion upstream from the portion where the breather tube 114 is inserted into the retention tube portion 125. The other end portion of the breather tube 114 retained in the retention groove 127 is inserted and retained in the retention tube portion 125 while being bent in a substantially L-shaped configuration. [0040]
Referring also to Fig. 13, a support tube portion 129 surrounding the crankshaft 35 in an endless fashion integrally protrudes from the right-side case half 31R of the crankcase 31. A right cover 131 that defines a power transmission chamber 130 between it and the right-side case half 31R is joined to the outer end of the support tube portion 129. The crankshaft 35 penetrates the right cover 131 in a fluid-tight and rotatable manner. [0041]
A generator 134 is disposed on the outer side with respect

to the right cover 131. The generator 134 includes a stator 132 fixed to the right cover 131, and an outer rotor 133 fixed to the crankshaft 35 so as to surround the stator 132. A fan 135 is fixed to the crankshaft 35 on the outer side with respect to the generator 134. The fan 135 has a plurality of vanes 135b integrally provided in the outer peripheral portion of a base portion 135a that is fastened onto the outer rotor 133 of the generator 134 by means of a plurality of bolts 156. [0042]
Referring also to Fig. 14, an oil pump 112 is attached to the right-side case half 31R inside the power transmission chamber 130. A pump housing 136 of the oil pump 112 is composed of an end plate 137 that abuts on the right-side case half 31R, and a pump cover 138 fastened onto the right-side case half 31R while sandwiching the end plate 137 between the pump cover 138 and the right-side case half 31R. An inner rotor 139 and an outer rotor 140 are accommodated in the pump housing 136. Further, a pump shaft 141, which is coupled to the inner rotor 139 in a manner that does not allow relative rotation, is rotatably supported by the pump 138 and the right cover 131. [0043]
A driven gear 142 is mounted to the pump shaft 141 via a pin 143 in a manner not allowing relative rotation. A drive gear
144 in meshing engagement with the driven gear 142 is secured to
the crankshaft 35 by press-fitting or the like. Further, a drive
sprocket 145 is secured to the pump shaft 141 by press-fitting or
the like. An endless chain 147 is wound around the drive sprocket
145 and a driven sprocket 146 that is mounted by means of a pin

150 to a pump shaft 149 of a cooling water pump 148 in a manner
that does not allow relative rotation.
[0044]
A pump housing 151 of the cooling water pump 148 is composed of a housing main portion 152 formed integrally with the right cover 131, and a pump cover 153 fastened onto the housing main portion 152. An impeller 154 arranged within a pump chamber 155 formed by the pump housing 151 is fixed to the pump shaft 141 supported in a fluid-tight and rotatable manner by the housing main portion 152. [0045]
Incidentally, a cooling water jacket 158 is formed in the cylinder block 32 and cylinder head 33 of the engine body 30. A discharge port 159 provided in the housing main portion 152 of the pump housing 151 is connected to an inlet 158a of the cooling water jacket 158 provided in the cylinder block 32 via a connecting pipe 160. Accordingly, one end portion of the connecting pipe 160 is brought into fitting engagement with the inlet 158a of the cooling water jacket 158 in a fluid-tight manner; upon fastening the right cover 131 having the housing main portion 152 integrally provided therewith onto the right-side case half 31R of the crankcase 31, the other end portion of the connecting pipe 160 is brought into fitting engagement with the discharge port 159 in a fluid-tight manner. [0046]
As shown in Fig. 13, the fan 135 fixed to the crankshaft 35 is surrounded by a fan cover 161 that is fastened to the right-side case half 31R of the crankcase 31. A radiator 162, which is

arranged on the outer side of the fan 135 so as to be cooled by the cooling air sucked in by the fan 135, is attached to the fan cover 161 by means of a plurality of bolts 163. [0047]
The radiator 162 is formed by coupling an upper tank 164 and a lower tank 165, which are arranged in parallel in the horizontal direction, to each other by a radiator core 166. A radiator cover 168, which has a circular louver 167 substantially corresponding to the rotational trajectory of the outer end of the fan 135 and surrounds the radiator 162 from the outer side, is attached to the fan cover 161 with the louver 167 being opposed to the radiator core 166. [0048]
An exhaust pipe cover portion 168a is provided integrally with a lower portion of the radiator cover 168. The exhaust pipe cover portion 168a covers at least a part of the exhaust pipe 50, which extends downward from the cylinder head 33 and passes below the engine body 30 in the power unit P to be extended rearward; in this embodiment, the exhaust pipe cover portion 168a covers the upper half portion of the exhaust pipe 50. [0049]
Incidentally, the air sucked in through the louver 167 and the radiator core 166 due to the rotation of the fan 135 forms a scroll flow within the fan cover 161. As shown in Fig. 15, an air-exhaust port 170 arranged on the plane orthogonal to the scroll flow indicated by the arrow 169 is formed in a lower portion of the fan cover 161 so as to open obliquely downward to the front. Due to the formation of the air-exhaust port 170 as

described above, the scroll flow inside the fan cover 161 is rectified without being disturbed, thereby making it possible to suppress wind noise that is generated as the air flows through the louver 167. [0050]
Further, a force directed upward along the outer periphery of the fan cover 161 is exerted on the air flow discharged from the air-exhaust port 170. In this regard, the air cleaner 45 is arranged above the fan cover 161, and the air cleaner 45 has the suction port 122a that is forwardly open. Therefore, there is a possibility that the air that has been heated by passing through the radiator core 166 may be sucked in by the air cleaner 45. In view of this, as shown in Fig. 16, in order to prevent the air that has ascended along the outer periphery of the fan cover 161 from the air-exhaust port 170 from flowing toward the air cleaner 45 side, for example, two vertically spaced blocking walls 171, 172 are provided above the air-exhaust port 170 so as to protrude from an upper portion of the fan cover 161. It should be noted that in Fig. 16, the blocking walls 171, 172 are shaded to clearly indicate the blocking walls 171, 172. [0051]
The blocking walls 171, 172 as described above allow the air cleaner 45 to suck in fresh unheated air without sucking in the heated air discharged from the fan cover 161. [0052]
A thermostat 175 for controlling the flow rate at which the cooling water discharged from the cooling water jacket 158 flows into the radiator 162 is arranged by the side of the cylinder

block 32 in the engine body 30. The thermostat 175 is attached to the pump cover 153 of the pump housing 151 in the cooling water pump 148 so as to communicate with a suction port 176 provided in the pump cover 153. [0053]
Furthermore, the thermostat 175 is arranged in front of the radiator 162 so as to be at substantially the same position as the radiator core 166 of the radiator 162 along the width direction of the body frame 21. The thermostat 175 is covered, together with the radiator 162, by the radiator cover 168 from the outer side. [0054]
As shown in Fig. 14, a connecting pipe 177 communicating with an outlet 158b of the cooling water jacket 158 is provided near the intake port 46 and in the right side surface of the cylinder head 33. The upstream end of a cooling water hose 178 is connected to the connecting pipe 177. Further, a T-shaped joint 179 is connected to the downstream end of the cooling water hose 178. A cooling water hose 180, whose upstream end is connected to the joint 179, is connected to the upper tank 164 of the radiator 162. Further, the joint 179 and the thermostat 175 are connected to each other by a bypass cooling-water hose 181 for introducing the cooling water from the cooling water jacket 158 to the thermostat 175 side. The lower tank 165 of the radiator 162 and the thermostat 175 are connected to each other by a cooling water hose 182. [0055]
Next, the operation according to this embodiment will be

described. One end portion of the driven shaft 81, which is a component of the power transmission system T constituting the power unit P together with the engine E, is rotatably supported on the outer case 73 facing the transmission chamber 75 as a dry space, via the ball bearing 90 and the cylindrical bush 93, which is formed of porous sintered metal and mounted to the driven shaft 81 while being impregnated with oil. The bush 93 is press-fitted into the inner race 90a of the ball bearing 90. [0056]
Therefore, it is unnecessary to perform complicated machining on the bush 93 to effect lubrication, and also the lubricity at the portion supporting one end of the driven shaft 81 is improved, whereby a long-life and low-cost supporting structure can be realized without using a special bearing material or lubricating oil. Further, due to the provision of the bush 93 between the ball bearing 90 and the driven shaft 81, as compared with the case where the driven shaft 81 is directly brought into fitting engagement with the ball bearing 90, the wear of the driven shaft 81 due to friction can be reduced, and the bush 93 can be readily replaced if the bush 93 is worn out. Low cost is achieved in this respect as well. [0057]
Further, the outer race 90b of the ball bearing 90 is fitted and fixed onto the bearing housing 73a of the outer case 73. Due to the provision of the bush 93 between the ball bearing 90 and the driven shaft 81, the outer diameter of the ball bearing 90 can be made relatively large, which makes it possible to reduce the contact pressure exerted on the outer case 73 onto

, which the ball bearing 90 is fitted and fixed. [0058]
Incidentally, the power transmission system T constituting the power unit P together with the engine E is composed of the continuously variable transmission 78 for varying the output speed of the engine E, and the gear reducer mechanism 79 for reducing the output speed of the continuously variable transmission 78 and transmitting it to the rear wheel WR. The transmission chamber 75 accommodating the continuously variable transmission 78, and the speed reducer chamber 76 accommodating the gear reducer mechanism 79 and storing oil in a lower portion thereof are formed inside the power transmission case 71 that is connected to the engine body 30 and provided so as to extend by the side of the rear wheel WR. The breather tube 114 whose one end is connected to the delivery pipe portion 113, which is provided to an upper portion of the gear reducer case 74 in the power transmission case 71 so as to communicate with an upper portion in the speed reducer chamber 76, is extended forward along an upper portion of the power transmission case 71. The other end of the breather 114 is upwardly open. [0059]
Therefore, it is possible to reliably prevent muddy water thrown up by the running scooter type vehicle from entering the breather tube 114. Further, by extending the breather tube 114 forward along the power transmission case 71, the length of the passage inside the breather tube 114 can be increased to facilitate gravity separation of oil, thereby making it possible

other end of the breather tube 114. [0060]
Further, the air cleaner 45 is arranged above the power unit P, and the other end portion of the breather tube 114 is retained by the breather outlet cover 119a, which is provided to the cleaner case 116 of the air cleaner 45, so as to be covered by the breather outlet cover 119a from the outer side. Accordingly, since it is unnecessary to provide a dedicated member for retaining the other end portion of the breather tube 114, the number of parts can be reduced. Further, since the other end portion of the breather tube 114 is covered from the outer side, it is also possible to achieve an improvement in terms of outward appearance. [0061]
Further, the exhaust port 49 is provided in the lower side surface of the cylinder head 33 equipped to the engine E, the exhaust pipe 50 whose upstream end is connected to the exhaust port 49 extends downward to the rear from the cylinder head 33 while passing through the portion below the engine body 30, and the hose 61 for introducing secondary air for purifying the exhaust gas is connected to the exhaust port 49 via the connecting pipe 62 made of metal. The U-shaped portion 62a that is bent in a substantially U-shaped configuration is formed in a part of the connecting pipe 62, and as seen in side view, the U-shaped portion 62a is arranged between the lower side surface of the cylinder head 33 and the exhaust pipe 50. [0062]
Accordingly, the formation of the U-shaped portion 62a

makes it possible to adjust the length of the connecting pipe 62, whereby an elongated connecting pipe 62 can be arranged through effective use of the free space between the lower side surface of the cylinder head 33 and the exhaust pipe 50. Furthermore, the U-shaped portion 62a is arranged below the cylinder head 33. Accordingly, even when the air cleaner 45 is arranged above the power unit P as in this embodiment, the heat radiated from the U-shaped portion 62a can be blocked by the cylinder head 33 so that the heat exerts no influence on the air cleaner 45 side, thereby making it possible to prevent the air cleaner 45 from sucking in heated air. [0063]
Further, since a part of the U-shaped portion 62a is arranged between the cylinder head 33 and the exhaust pipe 50, by setting the length of the U-shaped portion 62a of the connecting pipe 62 sufficiently large to thereby sufficiently lower the temperature at the upstream end of the connecting pipe 62, and by heating a part of the U-shaped portion 62a with the heat radiated from the exhaust pipe 50, heated secondary air can be supplied to the exhaust port 49 to achieve enhanced exhaust-gas purification performance. [0064]
Further, the radiator 162, and the thermostat 175 for controlling the flow rate at which the cooling water discharged from the cooling water jacket 158 flows into the radiator 162 are arranged on the right side of the engine body 30 having the cooling water jacket 158. Since the radiator 162 and the thermostat 175, which is arranged along the width direction of

the body frame 21 at. substantially the same position as the radiator core 165 of the radiator 162, are covered by the common radiator cover 168 from the outer side, the number of parts and the number of assembly man-hours can be reduced in covering the radiator 162 and the thermostat 175 from the outer side. [0065]
Further, the exhaust pipe 50 connected to the cylinder head 33 is extended rearward while passing through the portion below the engine body 30, and the exhaust pipe cover portion 168a, which covers at least a part of the exhaust pipe 50 from the outer side, is provided integrally with the radiator cover 168. Accordingly, in addition to the radiator 162 and the thermostat 175, at least a part of the exhaust pipe 50 below the engine body 30 is covered by the radiator cover 168, whereby a further reduction can be achieved in the number of parts. [0066]
Further, the cooling water pump 148 is attached to the engine body 30, and the thermostat 175 is attached to the pump cover 153 in the pump housing 151 of the cooling water pump 148. Accordingly, the cooling water pump 148 can be arranged while effectively using the space between the thermostat 175, which is located at substantially the same position as the radiator core 166 along the width direction of the body frame 21, and the engine body 30, thereby making it possible to realize compact construction around the engine E. [0067]
While an embodiment of the present invention has been described above, the present invention is not limited to the

^m) >o [Description of Reference Numerals]
[0069]
21...Vehicle body frame
30...Enqine body
33...CyJi nder head
50. . .Exhaust pipe
148...Cooling water pump
151...Pump housing
158...Cooling water jacket
1. 62 . . . Radiator
165...Radiator core
1 68 . . . Radiator cover
168a... Exhaust pipe cover portion
175 ... Thermostat





We claim:
1. A motorcycle comprising a radiator (162) and a thermostat (175) that are arranged on one side of an engine body (30) having a cooling water jacket (158) and mounted to a body frame (21), the thermostat (175) controlling a flow rate at which cooling water discharged from the cooling water jacket (158) flows into the radiator (162), wherein the thermostat is arranged along the body frame (21) at the middle of the radiator core (165) as viewed in the front-rear direction of the motorcycle, and the radiator (162) and thermostat (175) are covered by a common radiator cover (168) from an outer side.
2. The motorcycle as claimed in claim I, wherein and exhaust pipe (50) connected to a cylinder head (33) of the engine body (30) is extended rearward while passing below the engine body (30), and an exhaust pipe cover portion (168a) covering at least a part of the exhaust pipe (50) from an outer side is integrally provided to the radiator cover (168).
3. The motorcycle as claimed in claim 1 or 2, wherein the thermostat (175) is attached to a pump housing (151) of a cooling water pump (148) that is attached to the engine body (30).

Documents:

2120-DEL-2006-Abstract-(13-08-2009).pdf

2120-del-2006-abstract.pdf

2120-DEL-2006-Claims-(13-08-2009).pdf

2120-del-2006-claims.pdf

2120-DEL-2006-Correspondence-Others (18-01-2010).pdf

2120-DEL-2006-Correspondence-Others-(09-12-2009).pdf

2120-DEL-2006-Correspondence-Others-(13-08-2009).pdf

2120-del-2006-correspondence-others.pdf

2120-DEL-2006-Description (Complete)-(13-08-2009).pdf

2120-del-2006-description (complete).pdf

2120-DEL-2006-Drawings-(13-08-2009).pdf

2120-del-2006-drawings.pdf

2120-DEL-2006-Form-1-(13-08-2009).pdf

2120-del-2006-form-1.pdf

2120-del-2006-form-18.pdf

2120-DEL-2006-Form-2-(13-08-2009).pdf

2120-del-2006-form-2.pdf

2120-DEL-2006-Form-3 (18-01-2010).pdf

2120-DEL-2006-Form-3-(13-08-2009).pdf

2120-del-2006-form-3.pdf

2120-del-2006-form-5.pdf

2120-DEL-2006-GPA-(13-08-2009).pdf

2120-del-2006-gpa.pdf

2120-DEL-2006-Petition-137-(13-08-2009).pdf

2120-DEL-2006-Petition-138-(13-08-2009).pdf

abstract.jpg


Patent Number 240545
Indian Patent Application Number 2120/DEL/2006
PG Journal Number 22/2010
Publication Date 28-May-2010
Grant Date 17-May-2010
Date of Filing 26-Sep-2006
Name of Patentee HONDA MOTOR CO., LTD
Applicant Address 1-1, Minami-Aoyama 2-chome, Minato-ku, Tokyo 107-8556, Japan.
Inventors:
# Inventor's Name Inventor's Address
1 TSUGIO IKEDA C/O Honda R&D Co., Ltd., of 4-1, Chuo 1-chome, Wako-shi, Saitama 351-0193, Japan,
2 KAYOKO YAMAZAKI C/O Honda R&D Co., Ltd., of 4-1, Chuo 1 chome, Wako-shi, Saitama 351-0193, Japan,
3 KAYOKO YAMAZAKI C/O Honda R&D Co., Ltd., of 4-1, Chuo 1 chome, Wako-shi Saitama 351-0193, Japan,
PCT International Classification Number B62J17/00
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 2005-325193 2005-11-09 Japan