Title of Invention	AIR CLEANER STRUCTURE IN MOTORCYCLE
Abstract	[Subject] To improve the workability of a cleaning work in a sub chamber, improve the air cleaner assembling performance and increase the degree of design freedom. [Solution] An air cleaner case 81 has a combined structure comprising a case body 82 and an air cleaner cover 84 mating with the case body and is flat in a direction orthogonal to a mating surface 81A between the case body 82 and the air cleaner cover 84, a connecting tube 48 communicating with an engine side is connected to the case body 82 so as to direct itself to a plane 81B passing the mating surface 81A, a separator 101 for forming a sub chamber 106 is attached removably to the case body 82 so as to cover a connecting tube connection 105 and so as to confront an end portion 48b of the connecting tube 48, and an air cleaner element 103 is made cylindrical and is removably fitted in an element connecting hole 101b formed in the separator 101, [Selected Drawing] Fig. 3

Title of Invention

AIR CLEANER STRUCTURE IN MOTORCYCLE

Abstract

[Subject] To improve the workability of a cleaning work in a sub chamber, improve the air cleaner assembling performance and increase the degree of design freedom. [Solution] An air cleaner case 81 has a combined structure comprising a case body 82 and an air cleaner cover 84 mating with the case body and is flat in a direction orthogonal to a mating surface 81A between the case body 82 and the air cleaner cover 84, a connecting tube 48 communicating with an engine side is connected to the case body 82 so as to direct itself to a plane 81B passing the mating surface 81A, a separator 101 for forming a sub chamber 106 is attached removably to the case body 82 so as to cover a connecting tube connection 105 and so as to confront an end portion 48b of the connecting tube 48, and an air cleaner element 103 is made cylindrical and is removably fitted in an element connecting hole 101b formed in the separator 101, [Selected Drawing] Fig. 3

Full Text	[Name of Document] Specification [Title of the Invention] AIR CLEANER STRUCTURE IN MOTORCYCLE [Technical Field] [0001] The present invention relates to an improvement of an air cleaner structure in a motorcycle. [Background Art] [0002] As a conventional air cleaner structure in a motorcycle there is known an air cleaner structure wherein a sub chamber is provided within an air cleaner case (see, for example, Patent Document 1). [Patent Document 1] JP-A No. 2001-90623 [0003] Figs. 3, 4 and 6 in Patent Document 1 will be described below. The interior of an air cleaner case 42 is partitioned by a filter element 43 into an element front chamber 44 as a dirty side and an element rear chamber 4 5 as a clean side. A part of the space on the clean side is partitioned by a partition wall 46 to form a sub chamber 48 and a blowby hose 34 for the recycle of blowby gas from a crankcase of an engine is connected to the sub chamber 48. The sub chamber 48 is used as an oil catch tank and a resonator for attenuating an intake noise. [Disclosure of the Invention] [Problems to be Solved by the Invention] [0004] A chamber lid 64 is provided in the sub chamber 48 and it is fixed with machine screws 65 so as to permit opening and closing of the sub chamber 48. However, an opening closed with the chamber lid 64 is formed in a narrow side face of the sub chamber which is in a flat shape, so when cleaning the interior of the sub chamber, a worker' s hand is difficult to get into the interior and there is a possibility that it will become difficult to carry out the cleaning work. [0005] Moreover, in an air cleaner device 25 of a motorcycle it is preferable that some of parts in the air cleaner case 42, like other parts, be assembled into an assembly beforehand in order to improve the assembling performance on an assembly line. Further, in order to enhance the design freedom, it is preferable that the volume of the sub chamber 4 8 which exerts an influence on engine performance and intake noise, as well as the specification of the filter element 43, be changeable easily. It is an object of the present invention to improve the workability of works such as a cleaning work in the sub chamber, also improve the air cleaner assembling performance and enhance the design freedom. [Means for Solving the Problems] [0006] According to the invention defined in Claim 1 there is provided, in an air cleaner structure in a motorcycle wherein the interior of an air cleaner case is partitioned by an air cleaner element into a dirty side and a clean side and a sub chamber is formed on the clean side and is brought into communication with the interior of a crankcase of an engine through a blow-by hose, the improvement characterized in that the air cleaner case has a combined structure comprising a case body and an air cleaner cover mating with the case body and the air' cleaner case is flat in a direction orthogonal to a mating surface between the case body and the air cleaner cover, a connecting tube communicating with the engine side is connected to the case body so as to direct itself to a plane passing the mating surface, a separator for forming the sub chamber is attached removably to the case body so as to cover the connection of the connecting tube to the case body and so as to confront an end portion of the connecting tube, and the air cleaner element is cylindrical and is removably fitted in a hole formed in the separator. [0007] In connection with operation, since the separator is attached to the case body of the flat air cleaner case, it is possible to form a sub chamber which is flat in a direction orthogonal to the mating surface. By removing the air cleaner cover from the air cleaner case and removing the air cleaner element from the separator, further by removing the separator from the case body, an inner wall of the flat sub chamber is opened largely. [0008] The separator can constitute an assembly together with the air cleaner element which is fitted removably in the hole of the separator. Further, the volume of the sub chamiber and the specification of the air cleaner can be changed by changing the shape of the separator and the diameter of the hole formed in the separator. [0009] According to the invention defined in Claim 2, the air cleaner is disposed in a longitudinal direction of a vehicle body and sideways of a rear wheel so as to straddle a rear cushion unit for the rear wheel,, the mating surface between the case body and the air cleaner cover extends in the longitudinal direction of the vehicle body, the connecting tube is connected to the case body on a front side with respect to the rear cushion unit and from a transversely central side of the vehicle body, and the separator is disposed throughout the whole of the front side with respect to the rear cushion unit. [0010] In connection with operation, since the mating surface between the case body and the air cleaner cover directs itself in the longitudinal direction of the vehicle body, the cleaner does not overhang in the transverse direction of the vehicle body, and the volume of the air cleaner is increased by forming the air cleaner long in the longitudinal direction of the vehicle body. [0011] Besides, since the separator is disposed throughout the whole of the front side with respect to the rear cushion unit, it is possible to enlarge the area of the separator and the interior of the sub chamber is opened largely upon removal of the separator, [0012] According to the invention defined in Claim 3, the separator is formed so as to surround the connection of the connecting tube to the case body. In connection with operation, a dead space having unevenness and formed around the connecting tube connection inside the case body can be utilized effectively as the sub chamber. [0013] According to the invention defined in Claim 4, the separator is clamped to the case body with machine screws, the machine screws being.disposed at positioned not overlapping the air cleaner element when seen axially of the air cleaner element. In connection with operation, since the air cleaner element and the machine screws do not overlap each other when seen axially of the air cleaner element, the air cleaner element does not overhang in the transverse direction of the vehicle body. [0014] According to the invention defined in Claim 5, an L-shaped drain pipe comprising a vertical portion extending vertically and a horizontal portion extending horizontally is connected to the sub chamber, the horizontal portion being provided with an engaging portion to be engaged with and held by the case body. [0015] In connection with operation, force may act on the drain pipe during maintenance or upon vibration of the vehicle body, but since the engaging portion provided in the drain pipe is engaged with and held by the case body, there is no fear of excessive vibration even when force is exerted on the drain pipe. [0016] According to the invention defined in Claim 6, the engaging portion is a connecting portion for connection between an upstream portion and a downstream portion of the drain pipe. In connection with operation, since the drain pipe is divided into an upstream portion and a downstream portion, each part becomes shorter. Besides, separate materials may be selected for the upstream portion and the downstream portion respectively. [Effect of the Invention] [0017] In the invention of Claim 1, the air cleaner case has a combined structure comprising a case body and an air cleaner cover mating with the case body and the air cleaner case is flat in a direction orthogonal to a mating surface between the case body and the air cleaner cover, a connecting tube communicating with the engine side is connected to the case body so as to direct itself to a plane passing the mating surface^ a separator for forming the sub chamber is attached removably to the case body so as to cover the connection of the connecting tube to the case body and so as to confront an end portion of the connecting tube, and the air cleaner element is cylindrical and is removably fitted in a hole formed in the separator. Consequently, the sub chamOoer also becomes flat in the direction orthogonal to the mating surface. Besidesr by removing the air cleaner cover from the case body and removing the air cleaner element from the separator, further, by removing the separator from the case body, the inner wall of the sub chamber is opened largely, so that for example in a cleaning work it becomes easier for a worker' s hand to get into the whole of the interior of the sub chamber, whereby it is possible to improve the workability. [0018] The separator and the air cleaner element may be provided as an assembly. In this case, by subassembling the separator and the air cleaner element in advance, it is possible to decrease the number of assembling steps on an assembly line and hence possible to improve the productivity. Consequently, it is possible to reduce the cost of the air cleaner. [0019] For example, by adopting a separator shape which swells or is depressed with respect to a flat plate, it is possible to change the volume of the sub chamber and hence possible to change the clean side volume which exerts an influence on vehicular engine performance and drivability and the resonator volume which influences the intake noise. Further, the specification of the air cleaner element can be changed by only a change made to the separator, thus making it possible to increase the design freedom of the air cleaner. [0020] In the invention of Claim 2, the air cleaner is disposed long in a longitudinal direction of a vehicle body and sideways of a rear wheel so as to straddle a rear cushion unit for the rear wheel, the mating surface between the case body and the air cleaner cover extends in the longitudinal direction of the vehicle body, the connecting tube is connected to the case body on a front side with respect to the rear cushion unit and from a transversely central side of the vehicle body, and the separator is disposed throughout the whole of the front side with respect to the rear cushion unit. According to this construction, not only the volume of the air cleaner can be made large while suppressing the projection of the air cleaner in the transverse direction of the vehicle body, but also the area of the separator can be made large. Therefore, when the separator is removed, the interior of the sub chamber is opened largely, whereby not only the workability of for example a cleaning work for the sub chamber can be further improved, but also the degree of freedom on the shape of the sub chamber can be further increased. [0021] In the invention of Claim 3, the separator is formed so as to surround the connection of the connecting tube to the case body. Therefore, the volume of the sub chamber can be further enlarged by utilising a dead space formed in the connection of the connecting tube^ whereby it is possible to prevent an increase in size of the air cleaner. [0022] In the invention of Claim 4, the separator is clamped to the case body with machine screws, the machine screws being disposed at positions not overlapping the air cleaner element when seen axially of the air cleaner element. Thus, even with the machine screws, the air cleaner element does not overhang in the transverse direction of the vehicle body and it is possible to not only make the vehicle body compact but also make the vehicle width small. [0023] In the invention of Claim 5, an L-shaped drain pipe comprising a vertical portion extending vertically and a horizontal portion extending horizontally is connected to the sub chamber, the horizontal portion being provided with an engaging portion to be engaged with and held by the case body. According to this construction, even when force is exerted on the drain pipe during maintenance or upon vibration of the vehicle body, vibration of the drain pipe can be prevented by the engaging portion* [0024] In the invention of Claim 6, the engaging portion is a connecting portion for connection between an upstream portion and a downstream portion of the drain pipe. Since it is thus possible to divide the drain pipe into an upstream portion and a downstream portion, each part can be made short and hence the storage thereof in a factory and the transport thereof are easy. [0025] Moreover, it is possible to increase the degree of freedom in the selection of materials. For example, the upstream portion may be formed by resin molding and the downstream portion may be formed by a rubber hose. Further, even when force is exerted on the drain pipe during maintenance or upon vibration of the vehicle body, an excessive displacement of the upstream portion can be inhibited by the engaging portion. [Best Mode for Carrying Out the Invention] [0026] The best mode for carrying out the present invention will be described hereinunder with reference to the accompanying drawings. The drawings should be seen in the directions of reference numerals. Fig. 1 is a side view of a motorcycle adopting an air cleaner structure according to the present invention. In a motor cycle 10, which is a scooter type vehicle, a front fork 13 is attached steerably to a head pipe 12 which constitutes a front end of a body frame 11, a bar handlebar 16 is secured to a steering shaft 14 connected to the front fork 13, a front wheel 17 is secured to a lower end of the front fork 13, a power unit 22 is supported by an intermediate portion of a main frame 18 vertically swingably through a link 21, the main frame 18 constituting the body frame 11, a rear wheel is secured to a rear end of the power unit 22, and a rear cushion unit 24 is connected bridgewise to both the rear end of the power unit 22 and a rear portion of a main frame 18. [0027] The body frame 11 is made up of the head pipe 12, a down frame 26 extending downward from the head pipe 12, and the main frame 18 extending right and left backward from a lower portion of the down frame 26, further extending backward and obliquely upward at the rear portion thereof and with right and left rear ends connected together. The numeral 27 denotes a lower frame for supporting a main stand 28. [0028] A front portion of the main frame 18 supports a step floor 31 via a support member (not shown), and a support shaft 34 of a brake pedal 33 for actuating a rear wheel brake device 32 to brake the rear wheel 23 is disposed between the main frame 18 and the step floor 31. Numeral 35 denotes a brake cable for connection between the brake pedal 33 and the rear wheel brake device 32. Numeral 36 denotes a brake locking/unlocking mechanism for a so-called "parking brake" involving maintaining or releasing a depressed state of the brake pedal 33 to maintain or cancel a braked state of the rear wheel 23. Numeral 36a denotes an operating part provided in the brake locking/unlocking mechanism and numeral 36b denotes a brake locking/unlocking cable for connection between the operating part 36a and the rear wheel brake device 32. [0029] The power unit 22 is made up of an engine 38 which constitutes a front portion of the power unit and a continuously variable transmission 39 integral with a rear portion of the engine 38. The engine 38 is a drive source having an upper portion to which an intake device 41 is connected and a lower portion to which an exhaust device 42 is connected. [0030] The intake device 41 is made up of an intake pipe 4 6 connected to an upper portion of a cylinder head 44 of the engine 38, a throttle body 47 connected to the intake pipe 46, and an air cleaner 51 connected tO'the throttle body 47 via a connecting tube 48. The air cleaner 51 is attached to an upper portion of a rear portion of the power unit 22. [0031] The exhaust device 42 is made up of an exhaust pipe 54 connected to a lower portion of the cylinder head 44 and a muffler 55 connected to a rear end of the exhaust pipe 54. To the muffler 55 is connected a secondary air supply device 57 for the supply of air to exhaust gas present within the muffler 55 to burn unburned gas. [0032] In the figure, numeral 61 denotes a handlebar cover, numeral 62 denotes a front cover, 63 a license plate, 64 a leg shield, 66 a tandem seat, 67 a body cover, 68 an aperture formed in the body cover 67, 71 a tail lamp, and 72 a rear fender. [0033] Fig. 2 is a side view of the air cleaner according to the present invention (the arrow (FRONT) in the figure represents a vehicular front direction; this is true also in the following). The air cleaner 51 is provided with an air cleaner case 81. The air cleaner case 81 is made up of a case body 82 (not shown) disposed on the rear wheel 23 (see Fig. 1) side and an air cleaner cover 84, the air cleaner cover 84 being secured with plural machine screws 83 to the case body 82 at an outer side position of the vehicle body. [0034] A drain pipe 82c is integral with the case body 82, the drain pipe 82c projecting downward for discharging oil present within a sub chamber formed in the air cleaner case 81 to the exterior. A drain piping 8 6 is connected to the drain pie 82c. Numerals 82a and 82b denote mounting portions integral with the case body 82 for mounting the air cleaner 51 to the power unit 22 (see Fig. 1). [0035] The drain piping 86 is made up of an L-shaped pipe 87 connected to the drain pipe 82c and which is L-shaped in side view, a connecting pipe 88 connected to an end of the L-shaped pipe 87, a drain hose 91 connected to the connecting pipe 88, and a drain cap 92 which plugs up a free end of the drain hose 91. The connecting pipe 88 is engaged with a piping support portion 82A formed at a lower portion of the case body 82. Connecting portions of the drain pipe 82c, L-shaped pipe 87, connecting pipe 88, drain hose 91 and drain cap 92 are each clamped with a hose band 93. [0036] An intake duct 96 made of rubber for introducing the outside air into the air cleaner case 81 is attached to an upper portion of the air cleaner cover 84. The intake duct 96 is made up of a duct connecting portion 96a fitted in and connected to the air cleaner cover 84, an outer duct portion 96c extending to the vehicular front side from the duct connecting portion 96a and with an intake port 96b opening to the vehicular front side, and an inner duct portion 96e extending obliquely downward to the vehicular rear side within the air cleaner case 81 from the duct connecting portion 96a, the inner duct portion 96e having an exhaust port 96d. [0037] Fig. 3 is a sectional view (a partial plan view) of the air cleaner according to the present invention. The air cleaner 51 is made up of the air cleaner case 81, a separator 101 mounted within the case body 82, and an air cleaner element 103 supported at one end thereof by the separator 101 and secured at an opposite end thereof to the case body 82 with a machine screw 102. [0038] The interior of the air cleaner case 81 is partitioned into an upstream side in the flow of air of the air cleaner element 103, i.e., a dirty side 51D extending from the intake duct 96 (see Fig. 2) up to the air cleaner element 103, and a downstream side in the flow of air of the air cleaner element 103, i.e., a clean side 51C extending from the air cleaner element 103 up to the connecting tube 48. [0039] The case body 82 is integrally provided at a peripheral edge thereof with an annular recess 82B, while the air cleaner cover 84 is integrally provided at a peripheral edge thereof with an annular projection 84A. Thus, there is formed a combined, or mating, structure wherein the case body 82 and the air cleaner cover 84 are combined together, causing the annular recess 82B and the annular projection 84A to be fitted with each other. Numeral 81A denotes a mating surface between the case body 82 and the air cleaner cover 84, the mating surface 81A extending in the longitudinal direction of the vehicle. [0040] The separator 101 is a flat plate-like part disposed near a connecting tube connection hole 82d which is formed in the case body 82 for connection of the connecting tube 48. A fitting recess 101a is formed in a peripheral edge of the separator 101 and an annular projection 82e formed on the case body 82 is fitted in the fitting recess 101a. In this state the separator 101 is mounted to the case body 82 with plural machine screws 104. Numeral 48a denotes an annular recess formed in the connecting tube 48 so as to be fitted in the connecting tube connection hole 82d. [0041] The connecting tube connection hole 82d and the annular recess 48a are constituent portions of a connecting tube connection 105. The separator 101 is disposed in opposition to both the connecting tube connection 105 and an end 48b of the connecting tube 48. [0042] A flat space surrounded with the separator 101 and the case body 82 defines a sub chamber 106. A blow-by hose 107 communicating with the interior of a crankcase 38a (see Fig. 1) of the engine 38 is connected to the sub chamber 106 via a connecting port 82g. The sub chamber 106 functions as a catch tank which separates liquid oil from blow-by gas introduced from the interior of the crankcase 38a into the sub chamber 106 through the blow-by hose 107 and also functions as a resonator for diminishing an intake noise. [0043] An element connecting hole 101b for connection of the air cleaner element 103 is formed in the separator 101 and a sealing member 111 made of rubber is fitted in the element connecting hole 101b. Further, a small-diameter portion 103a of the air cleaner element 103 is removably fitted in the sealing member 111 along an inner periphery surface Ilia of the sealing member. [0044] The air cleaner element 103 is a part provided with frames 114 and 115 at both ends of a filter which has a generally elliptic outline. The frame 114 is formed with the small-diameter portion 103a and a bracket 116 attached to the frame 115 is secured with a machine screw 102 to a boss portion 82j which is integral with the case body 82. Numeral 118 denotes a nut member which is internally threaded for threaded engagement therein of the machine screw 102 and which is embedded in the boss portion 82j. [0045] Figs. 4 (a) to 4 (c) are explanatory diagrams of the drain piping and piping support portion according to the present invention. Fig. 4(a) is an exploded sectional view of the drain piping-86. The L-shaped pipe 87 is a part made of rubber and comprising a vertical portion 87a extending vertically and a horizontal portion 87b extending horizontally from a lower end of the vertical portion 87a, the vertical portion 87a and the horizontal portion 87b being integral with each other. [0046] The connecting pipe 88 includes a base portion 88a, a small-diameter pipe 88b and a large-diameter pipe 88c extending to both sides from the base portion 88a, and a flange portion 88e formed at an end of a neck portion 88d which is provided in the base portion 88a. [0047] The drain hose 91 is a part made of rubber and the drain cap 92 is made up of a plug portion 92a to be inserted into an end portion of the drain hose 91 and a large-diameter portion 92b formed at an end of the plug portion 92a and having a diameter larger than that of the plug portion 92a. The horizontal portion 87b, connecting pipe 88 and drain hoes 91 constitute a horizontal portion 86a of the drain piping 86. [0048] An end of the vertical portion 87a of the L-shaped pipe 87 is connected to the drain pipe 82c of the case body 82, the small-diameter portion 88b of the connecting pipe 88 is inserted into an end of the horizontal portion 87b of the drain pipe 82c, one end of the drain hose 91 is inserted into the large-diameter portion 88c of the connecting pipe 88, and the plug portion 92a of the drain cap 92 is inserted into an opposite end of the drain hose 91 to plug up the opposite end- Oil stored in the drain piping 86 is discharged upon removal of the drain cap 92. [0049] Fig. 4 (b) is a sectional view of the piping support portion 82A of the case body 82 which engages and holds the connecting pipe 88 (see Fig. 4(a)), taken along line 4-4 in Fig. 2. The piping support portion 82A is a portion projecting horizontally inwards of the vehicle body and having a slit 82rn and downwardly projecting lugs 82r and 82s. Fig. 4 (c) is a plan view of the piping support portion 82A. The piping support portion 82A has an expanded portion 82n within the slit 82m, [0050] Figs- 5(a) to 5(d) are explanatory diagrams showing the connecting pipe according to the present invention. Fig. 5(a) is a side view of the connecting pipe 88. The connecting pipe 88 includes, in the neck portion 88d thereof, a pair of plane portions 88g and 88h (only one reference numeral 88g is shown) formed opposedly to each other in the surface-back direction of the figure and a vertically long projecting portion 88j formed under one plane portion 88g and projecting to this side. Fig. 5(b) is a plan view of the connecting pipe 88. The plane portions 88g and 88h are formed in parallel with the extending direction of the small-diameter portion 88b and the large-diameter portion 88c. The projecting potion 88 j is formed so as to intersect the plane portions 88g and 88h perpendicularly. [0052] In Fig. 5(c), for engaging and holding the connecting pipe 88 with respect to the case body 82, the large-diameter portion 88c of the connecting pipe 88 is directed toward the slit 82m of the piping support portion 82A and the neck portion 88d is inserted into the slit 82m as indicated with an arrow. At this time, since the distance between the plane portions 88g and 88h is smaller than the width of the slit 82m, the neck portion 88d can be inserted smoothly into the slit 82m. [0053] For example, even when the small-diameter portion 88b is directed toward the slit 82m and an attempt is made to insert the neck portion 88d into the slit 82m, the projecting portion 88j of the connecting pipe 88 comes into abutment against the malassembly preventing lug 82r formed in the piping support portion 82A, thus obstructing the insertion, whereby a malassembly is prevented. [0054] In Fig. 5(d), the neck portion 88d causes the connecting pipe 88 inserted into the slit 82m to rotate 90° counterclockwise. As a result, since the plane portions 88g and 88h are each in a 90° turned position with respect to the slit 82m, the neck portion 88d becomes incapable of being disengaged from the expanded portion 82n. , The lug 82s functions as a stopper when the connecting pipe 88 is turned 90° or more. [0055] The operation of the air cleaner 51 constructed as above will be described below. Fig. 6 is a first operation diagram showing the operation of the air cleaner according to the present invention. Fig. 6 shows a state in which the air cleaner cover 84 (see Fig. 2) is removed from the air cleaner case 81 (see Fig. 2) and the air cleaner element 103 (see Fig. 3) is removed from the separator 101. The separator 101 is secured to the front side of the case body 82 with plural machine screws 104. [0056] Since the separator 101 is thus mounted substantially throughout the whole front portion of the case body 82, it is possible to enlarge the area of the separator 101 and hence possible to increase the volume of the sub chamber 106 (see Fig. 3) . [0057] Fig. 7 is a second operation diagram showing the operation of the air cleaner according to the present invention, in which the separator 101 (see Fig. 6) is removed from case body 82 in comparison with the state of Fig. 6. Numeral 82p appearing in plural positions denote a screw engaging hole formed in the case body 82 for engagement therein of machine screws 104 (see Fig. 6). By thus removing the separator 101 from the case body 82, an inner wall 106a of the sub chamber 106 is opened largely, so that for example a cleaning work for the interior of the sub chamber 106 can be done easily and it is possible to improve the workability. Fig. 8 is a perspective view showing a body cover of the motorcycle according to the present invention. A triangular recess 67a is formed in a front portion of the body cover indicated at 67. Further, in a rear wall 67b of the recess 67 is formed an elongated aperture 67A along one side of the triangle, the aperture 67A being inclined at an upper end thereof to a greater extent than a lower end thereof. [0059] The aperture 67A is formed centrally of the body cover 67 and above a rear end 31a of the step floor 31. Numeral 31b denotes a foot rest for a passenger sitting on a rear portion of the tandem seat 66 (see Fig. 1) and numeral 121 denotes a step under cover which covers the step floor 31 from below. [0060] Fig. 9 is a perspective view showing a principal portion on the back side of the body cover of the motorcycle according to the present invention. A cover member 123 is mounted to the back side of the body cover 31 so as to cover a lower half of the aperture 67A. Further, a trough member 124 having a J-shaped section is mounted to the back side of a lower end of the body cover 67 in such a manner that one end thereof covers the cover member 123 from below. [0061] The cover member 123 is formed with an inwards projecting wall 123a projecting inwards of the vehicle body. For example, when rain water enters the inside of the body cover 67 through the aperture 67A, the rain water is received by an inner groove of the trough member 124 and is discharged from between the trough member 124 and the inwards projecting wall 123a of the cover member 123, as indicated with an arrow. A pair of mounting portions formed on the cover member 123-for mounting the cover member to the body cover 67 are indicated at 123b. [0062] As shown in Fig. 3 referred to above, in an air cleaner structure in the motorcycle 10 (see Fig. 1) wherein the interior of the air cleaner case 81 is partitioned by the air cleaner element 103 into the dirty side 51D and the clean side 51C and the sub chamber 106 is formed on the clean side 51C and is brought into communication with the interior of the crankcase 38a (see Fig. 1) of the engine 38 (see Fig. 1) through the blow-by hose 107, the present invention is firstly characterized in that the air cleaner case 81 has a combined structure comprising the case body 82 and the air cleaner cover 84 mating with the case body 82 and the air cleaner case 81 is flat in a direction orthogonal to the mating surface between the case body 82 and the air cleaner cover 84, the connecting tube 48 communicating with the engine 38 side is connected to the case body 82 so as to direct itself to a plane 81B passing the mating surface 81A, the separator 101 for forming the sub chamber 106 is attached removably to the case body 82 so as to cover the connection (connecting tube connection 105) of the connecting tube 48 to the case body 82 and so as to confront the end 48b of the connecting tube 48, and the air cleaner element 103 is cylindrical and is removably fitted in the element connecting hole 101b formed in the separator 101. [0063] According to this construction, the sub chamber 106 also becomes flat in the direction orthogonal to the mating surface 81A, and by removing the air cleaner cover 84 from the case body 82 and the air cleaner element 103 from the separator 101, further, by removing the separator 101 from the case body 82, the inner wall 106a of the sub chamber 106 is opened largely, so that for example in a cleaning work it becomes easy for a worker's hand to enter the whole interior of the sub chamber 106, thus permitting improvement of the workability. [0064] If the separator 101 and the air cleaner element 103 are provided as an assembly, then by subassembling the separator 101 and the air cleaner element 103 in advance, it is possible to decrease the number of assembling steps on an assembly line and hence possible to improve the productivity. Consequently, it is possible to reduce cost of the air cleaner. [0065] For example, by adopting such a shape of the separator 101 as swelled or depressed with respect to a flat plate, it is possible to change the volume of the sub chamber 106 and hence possible to change the clean side volume which exerts an influence on vehicular engine performance and drivability and the resonator volume which influences the intake noise. Moreover, the specification of the air cleaner element 103 can be changed by only a change made to the separator 101, thus making it possible to increase the design freedom of the air cleaner 51. [0066] The present invention is secondly characterized in that the air cleaner 51 is disposed long in the longitudinal direction of the vehicle body and sideways of the rear wheel 23 (see Fig. 1) so as to straddle the rear cushion unit 24 for the rear wheel, the mating surface 81A between the case body 82 and the air cleaner cover 84 is extended in the longitudinal direction of the vehicle body, the connecting tube 48 is connected to the case body 82 on the front side with respect to the rear cushion unit 24 and from the transversely central side of the vehicle body, and the separator 101 is disposed throughout the whole of the front side with respect to the rear cushion unit 24. [0067] Thus, the air cleaner 51 is disposed sideways of the rear wheel 23 and long in the longitudinal direction of the vehicle body so as to straddle the rear cushion unit 24 for the rear wheel, the mating surface 81A between the case body 82 and the air cleaner cover 84 is extended in the longitudinal direction of the vehicle body, the connecting tube 48 is connected to the case body 82 on the front side with respect to the rear cushion unit 24 and from the transversely central side of the vehicle body, and the separator 101 is disposed throughout the whole of the front side. Therefore, not only the volume of the air cleaner 51 can be made large while suppressing the projection of the air cleaner 51 in the transverse direction of the vehicle body, but also the area of the separator 101 can be made large. Consequently, when the separator 101 is removed, the interior of the sub chamber 106 is opened largely, whereby not only the workability of for example a cleaning work for the sub chamber 106 can be further improved, but also the degree of freedom on the shape of the sub chamber 106 can be further increased. [0068] The present invention is thirdly characterized in that the separator 101 is formed so as to surround the connecting tube connection 105 to the case body 82. Therefore, the volume of the sub chamber 106 can be further enlarged by utilizing a dead space formed in the connecting tube connection 105, whereby it is possible to prevent an increase in size of the air cleaner 51. [0069] The present invention is fourthly characterized in that the separator 101 is clamped to the case body 82 with plural machine screws 104, the machine screws 104 being disposed at positions not overlapping the air cleaner element 103 when seen axially of the air cleaner element. Thus, even with the machine screws 104, the air cleaner element 103 does not overhang in the transverse direction of the vehicle body and it is possible to not only make the vehicle body compact but also make the vehicle width small. [0070] The present invention is fifthly characterized in that the L-shaped drain piping 86 comprising the vertical portion 87a extending vertically and the horizontal portion 86a extending horizontally is connected to the sub chamber 106, the horizontal portion 86a being provided with the connecting pipe 88 as an engaging portion to be engaged with and held by the case body 82. Therefore, even when force is exerted on the drain piping 86 during maintenance or upon vibration of the vehicle body, vibration of the drain piping 86 can be prevented by the connecting pipe 88. [0071] The present invention is sixthly characterized in that, as shown in Figs. 2 and 4(a), the engaging portion is the connecting pipe 88 which serves as a connecting portion for connection between the L-shaped pipe 87 as an upstream portion of the drain piping 86 and r the drrain hose 91 as a downstream portion. Since it is thus possible to divide the drain piping 86 into the L-shape pipe 87 and the drain hose 91, each part can be made short and hence the storage thereof in a factory and the transport thereof are easy. [0072] Although in this embodiment the connecting pipe 88 as a connecting portion is provided separately from the L-shaped pipe 87 as an upstream portion and the drain hose 91 as a downstream portion, this constitutes no limitation. The connecting pipe 88 may be formed integrally with the L-shaped pipe 87 or the drain hose 91. [Industrial Applicability] [0073] The air cleaner structure of the present invention is suitable for a motorcycle. [Brief Description of the Drawings] [0074] Fig. 1 is a side view of a motorcycle adopting an air cleaner structure according to the present invention. Fig. 2 is a side view of an air cleaner according to the present invention. Fig. 3 is a sectional view of the air cleaner according to the present invention. Fig. 4 is an explanatory diagram of a drain piping and a piping support portion according, to the present invention. Fig. 5 is an explanatory diagram showing a connecting pipe according to the present invention. Fig. 6 is a first operation diagram showing the operation of the air cleaner according to the present invention. Fig. 7 is a second operation diagram showing the operation of the air cleaner according to the present invention. Fig. 8 is a perspective view showing a body cover of a motorcycle according to the present invention. Fig. 9 is a perspective view showing a principal portion of a back side of the body cover of the motorcycle according to the present invention. [Explanation of Reference Numerals] [0075] 10 ... motorcycle. 24 ... rear cushion unit, 38 ... engine, 38a ... crankcase, 48 ... connecting tube, 51C ... clean side, 51D ... dirty side, 81 ... air cleaner case, 81A ... mating surface, 81B ... plane, 82 ... case body, 84 ... air cleaner cover, 86 ... drain pipe (drain piping), 86a ... horizontal portion, 87 ... upstream portion (L-shaped pipe) , 87a ... vertical portion, 88 ... engaging portion (connecting pipe) , 91 ... downstream portion (drain hose) , 101 ..,. separator, 101b ... hole (element connecting hole), 103 ... air cleaner element, 104 ... machine screw, 105 ... connecting tube connection, 106 ... sub chamber, 107 ... blow-by hose. [Name, of Document] Scope of Claims [Claim 1] An air cleaner structure in a motorcycle in which the interior of an air cleaner case is partitioned by an air cleaner element into a dirty side and a clean side and a sub chamber is formed on the clean side and is brought into communication with the interior of a crankcase of an engine through a blow-by hose, wherein: the air cleaner case has a combined structure including a case body and an air cleaner cover mating with the case body and the air cleaner case is flat in a direction orthogonal to a mating surface between the case body and the air cleaner cover; a connecting tube communicating with the engine side is connected to the case body so as to direct itself to a plane passing the mating surface; a separator for forming the sub chamber is attached removably to the case body so as to cover the connection of the connecting tube to the case body and so as to confront an end portion of the connecting tube; and the air cleaner element is cylindrical and is removably fitted in a hole formed in the separator. [Claim 2] The air cleaner structure in a motorcycle according to Claim 1. wherein: the air cleaner is disposed long in a longitudinal direction of a vehicle body and sideways of a rear wheel so as to straddle a rear cushion unit for the rear wheel; the mating surface between the case body and the air cleaner cover extends in the longitudinal direction of the vehicle body; . the connecting tube is connected to the case body on a front side with respect to the rear cushion unit and from a transversely central side of the vehicle body; and the separator is disposed throughout the whole of the front side with respect to the rear cushion unit. [Claim 3] The air cleaner structure in a motorcycle according to Claim 1 or Claim 2, wherein the separator is formed so as to surround the connection of the connecting tube to the case body. [Claim 4] The air cleaner structure in a motorcycle according to any of Claims 1 to 3, wherein the separator is clamped to the case body with machine screws, the machine screws being disposed at positions not overlapping the air cleaner element when seen axially of the air cleaner element. [Claim 5] The air cleaner structure in a motorcycle according to any of Claims 1 to 4, wherein an L-shaped drain pipe comprising a vertical portion extending vertically and a horizontal portion extending horizontally is connected to the sub chamber, the horizontal portion being provided with an engaging portion to be engaged with and held by the case body. [Claim 6] f

Full Text

[Name of Document] Specification [Title of the Invention]
AIR CLEANER STRUCTURE IN MOTORCYCLE [Technical Field] [0001]
The present invention relates to an improvement of an air cleaner structure in a motorcycle. [Background Art] [0002]
As a conventional air cleaner structure in a motorcycle there is known an air cleaner structure wherein a sub chamber is provided within an air cleaner case (see, for example, Patent Document 1).
[Patent Document 1] JP-A No. 2001-90623 [0003]
Figs. 3, 4 and 6 in Patent Document 1 will be described below.
The interior of an air cleaner case 42 is partitioned by a filter element 43 into an element front chamber 44 as a dirty side and an element rear chamber 4 5 as a clean side. A part of the space on the clean side is partitioned by a partition wall 46 to form a sub chamber 48 and a blowby hose 34 for the recycle of blowby gas from a crankcase of an engine is connected to the sub chamber 48. The sub chamber 48 is used as an oil catch tank and a resonator for attenuating an intake noise.
[Disclosure of the Invention] [Problems to be Solved by the Invention] [0004]
A chamber lid 64 is provided in the sub chamber 48 and it is fixed with machine screws 65 so as to permit opening and closing of

the sub chamber 48. However, an opening closed with the chamber lid 64 is formed in a narrow side face of the sub chamber which is in a flat shape, so when cleaning the interior of the sub chamber, a worker' s hand is difficult to get into the interior and there is a possibility that it will become difficult to carry out the cleaning work. [0005]
Moreover, in an air cleaner device 25 of a motorcycle it is preferable that some of parts in the air cleaner case 42, like other parts, be assembled into an assembly beforehand in order to improve the assembling performance on an assembly line. Further, in order to enhance the design freedom, it is preferable that the volume of the sub chamber 4 8 which exerts an influence on engine performance and intake noise, as well as the specification of the filter element 43, be changeable easily.
It is an object of the present invention to improve the workability of works such as a cleaning work in the sub chamber, also improve the air cleaner assembling performance and enhance the design freedom.
[Means for Solving the Problems] [0006]
According to the invention defined in Claim 1 there is provided, in an air cleaner structure in a motorcycle wherein the interior of an air cleaner case is partitioned by an air cleaner element into a dirty side and a clean side and a sub chamber is formed on the clean side and is brought into communication with the interior of a crankcase of an engine through a blow-by hose, the improvement characterized in that the air cleaner case has a combined structure comprising a case body and an air cleaner cover mating with the case body and the

air' cleaner case is flat in a direction orthogonal to a mating surface between the case body and the air cleaner cover, a connecting tube communicating with the engine side is connected to the case body so as to direct itself to a plane passing the mating surface, a separator for forming the sub chamber is attached removably to the case body so as to cover the connection of the connecting tube to the case body and so as to confront an end portion of the connecting tube, and the air cleaner element is cylindrical and is removably fitted in a hole formed in the separator. [0007]
In connection with operation, since the separator is attached to the case body of the flat air cleaner case, it is possible to form a sub chamber which is flat in a direction orthogonal to the mating surface.
By removing the air cleaner cover from the air cleaner case and removing the air cleaner element from the separator, further by removing the separator from the case body, an inner wall of the flat sub chamber is opened largely. [0008]
The separator can constitute an assembly together with the air cleaner element which is fitted removably in the hole of the separator.
Further, the volume of the sub chamiber and the specification of the air cleaner can be changed by changing the shape of the separator and the diameter of the hole formed in the separator. [0009]
According to the invention defined in Claim 2, the air cleaner is disposed in a longitudinal direction of a vehicle body and sideways of a rear wheel so as to straddle a rear cushion unit for the rear

wheel,, the mating surface between the case body and the air cleaner cover extends in the longitudinal direction of the vehicle body, the connecting tube is connected to the case body on a front side with respect to the rear cushion unit and from a transversely central side of the vehicle body, and the separator is disposed throughout the whole of the front side with respect to the rear cushion unit. [0010]
In connection with operation, since the mating surface between the case body and the air cleaner cover directs itself in the longitudinal direction of the vehicle body, the cleaner does not overhang in the transverse direction of the vehicle body, and the volume of the air cleaner is increased by forming the air cleaner long in the longitudinal direction of the vehicle body. [0011]
Besides, since the separator is disposed throughout the whole of the front side with respect to the rear cushion unit, it is possible to enlarge the area of the separator and the interior of the sub chamber is opened largely upon removal of the separator, [0012]
According to the invention defined in Claim 3, the separator is formed so as to surround the connection of the connecting tube to the case body.
In connection with operation, a dead space having unevenness and formed around the connecting tube connection inside the case body can be utilized effectively as the sub chamber. [0013]
According to the invention defined in Claim 4, the separator is clamped to the case body with machine screws, the machine screws

being.disposed at positioned not overlapping the air cleaner element when seen axially of the air cleaner element.
In connection with operation, since the air cleaner element and the machine screws do not overlap each other when seen axially of the air cleaner element, the air cleaner element does not overhang in the transverse direction of the vehicle body. [0014]
According to the invention defined in Claim 5, an L-shaped drain pipe comprising a vertical portion extending vertically and a horizontal portion extending horizontally is connected to the sub chamber, the horizontal portion being provided with an engaging portion to be engaged with and held by the case body. [0015]
In connection with operation, force may act on the drain pipe during maintenance or upon vibration of the vehicle body, but since the engaging portion provided in the drain pipe is engaged with and held by the case body, there is no fear of excessive vibration even when force is exerted on the drain pipe. [0016]
According to the invention defined in Claim 6, the engaging portion is a connecting portion for connection between an upstream portion and a downstream portion of the drain pipe.
In connection with operation, since the drain pipe is divided into an upstream portion and a downstream portion, each part becomes shorter. Besides, separate materials may be selected for the upstream portion and the downstream portion respectively. [Effect of the Invention] [0017]

In the invention of Claim 1, the air cleaner case has a combined structure comprising a case body and an air cleaner cover mating with the case body and the air cleaner case is flat in a direction orthogonal to a mating surface between the case body and the air cleaner cover, a connecting tube communicating with the engine side is connected to the case body so as to direct itself to a plane passing the mating surface^ a separator for forming the sub chamber is attached removably to the case body so as to cover the connection of the connecting tube to the case body and so as to confront an end portion of the connecting tube, and the air cleaner element is cylindrical and is removably fitted in a hole formed in the separator. Consequently, the sub chamOoer also becomes flat in the direction orthogonal to the mating surface. Besidesr by removing the air cleaner cover from the case body and removing the air cleaner element from the separator, further, by removing the separator from the case body, the inner wall of the sub chamber is opened largely, so that for example in a cleaning work it becomes easier for a worker' s hand to get into the whole of the interior of the sub chamber, whereby it is possible to improve the workability. [0018]
The separator and the air cleaner element may be provided as an assembly. In this case, by subassembling the separator and the air cleaner element in advance, it is possible to decrease the number of assembling steps on an assembly line and hence possible to improve the productivity. Consequently, it is possible to reduce the cost of the air cleaner. [0019]
For example, by adopting a separator shape which swells or is depressed with respect to a flat plate, it is possible to change the

volume of the sub chamber and hence possible to change the clean side volume which exerts an influence on vehicular engine performance and drivability and the resonator volume which influences the intake noise. Further, the specification of the air cleaner element can be changed by only a change made to the separator, thus making it possible to increase the design freedom of the air cleaner. [0020]
In the invention of Claim 2, the air cleaner is disposed long in a longitudinal direction of a vehicle body and sideways of a rear wheel so as to straddle a rear cushion unit for the rear wheel, the mating surface between the case body and the air cleaner cover extends in the longitudinal direction of the vehicle body, the connecting tube is connected to the case body on a front side with respect to the rear cushion unit and from a transversely central side of the vehicle body, and the separator is disposed throughout the whole of the front side with respect to the rear cushion unit. According to this construction, not only the volume of the air cleaner can be made large while suppressing the projection of the air cleaner in the transverse direction of the vehicle body, but also the area of the separator can be made large. Therefore, when the separator is removed, the interior of the sub chamber is opened largely, whereby not only the workability of for example a cleaning work for the sub chamber can be further improved, but also the degree of freedom on the shape of the sub chamber can be further increased. [0021]
In the invention of Claim 3, the separator is formed so as to surround the connection of the connecting tube to the case body. Therefore, the volume of the sub chamber can be further enlarged by

utilising a dead space formed in the connection of the connecting tube^ whereby it is possible to prevent an increase in size of the air cleaner.
[0022]
In the invention of Claim 4, the separator is clamped to the case body with machine screws, the machine screws being disposed at positions not overlapping the air cleaner element when seen axially of the air cleaner element. Thus, even with the machine screws, the air cleaner element does not overhang in the transverse direction of the vehicle body and it is possible to not only make the vehicle body compact but also make the vehicle width small. [0023]
In the invention of Claim 5, an L-shaped drain pipe comprising a vertical portion extending vertically and a horizontal portion extending horizontally is connected to the sub chamber, the horizontal portion being provided with an engaging portion to be engaged with and held by the case body. According to this construction, even when force is exerted on the drain pipe during maintenance or upon vibration of the vehicle body, vibration of the drain pipe can be prevented by the engaging portion* [0024]
In the invention of Claim 6, the engaging portion is a connecting portion for connection between an upstream portion and a downstream portion of the drain pipe. Since it is thus possible to divide the drain pipe into an upstream portion and a downstream portion, each part can be made short and hence the storage thereof in a factory and the transport thereof are easy. [0025]
Moreover, it is possible to increase the degree of freedom in

the selection of materials. For example, the upstream portion may be formed by resin molding and the downstream portion may be formed by
a rubber hose.
Further, even when force is exerted on the drain pipe during maintenance or upon vibration of the vehicle body, an excessive displacement of the upstream portion can be inhibited by the engaging portion.
[Best Mode for Carrying Out the Invention] [0026]
The best mode for carrying out the present invention will be described hereinunder with reference to the accompanying drawings. The drawings should be seen in the directions of reference numerals.
Fig. 1 is a side view of a motorcycle adopting an air cleaner structure according to the present invention. In a motor cycle 10, which is a scooter type vehicle, a front fork 13 is attached steerably to a head pipe 12 which constitutes a front end of a body frame 11, a bar handlebar 16 is secured to a steering shaft 14 connected to the front fork 13, a front wheel 17 is secured to a lower end of the front fork 13, a power unit 22 is supported by an intermediate portion of a main frame 18 vertically swingably through a link 21, the main frame 18 constituting the body frame 11, a rear wheel is secured to a rear end of the power unit 22, and a rear cushion unit 24 is connected bridgewise to both the rear end of the power unit 22 and a rear portion of a main frame 18. [0027]
The body frame 11 is made up of the head pipe 12, a down frame 26 extending downward from the head pipe 12, and the main frame 18 extending right and left backward from a lower portion of the down

frame 26, further extending backward and obliquely upward at the rear portion thereof and with right and left rear ends connected together. The numeral 27 denotes a lower frame for supporting a main stand 28. [0028]
A front portion of the main frame 18 supports a step floor 31 via a support member (not shown), and a support shaft 34 of a brake pedal 33 for actuating a rear wheel brake device 32 to brake the rear wheel 23 is disposed between the main frame 18 and the step floor 31. Numeral 35 denotes a brake cable for connection between the brake pedal 33 and the rear wheel brake device 32. Numeral 36 denotes a brake locking/unlocking mechanism for a so-called "parking brake" involving maintaining or releasing a depressed state of the brake pedal 33 to maintain or cancel a braked state of the rear wheel 23. Numeral 36a denotes an operating part provided in the brake locking/unlocking mechanism and numeral 36b denotes a brake locking/unlocking cable for connection between the operating part 36a and the rear wheel brake device 32. [0029]
The power unit 22 is made up of an engine 38 which constitutes a front portion of the power unit and a continuously variable transmission 39 integral with a rear portion of the engine 38. The engine 38 is a drive source having an upper portion to which an intake device 41 is connected and a lower portion to which an exhaust device 42 is connected. [0030]
The intake device 41 is made up of an intake pipe 4 6 connected to an upper portion of a cylinder head 44 of the engine 38, a throttle body 47 connected to the intake pipe 46, and an air cleaner 51 connected

tO'the throttle body 47 via a connecting tube 48. The air cleaner 51 is attached to an upper portion of a rear portion of the power unit
22. [0031]
The exhaust device 42 is made up of an exhaust pipe 54 connected to a lower portion of the cylinder head 44 and a muffler 55 connected to a rear end of the exhaust pipe 54. To the muffler 55 is connected a secondary air supply device 57 for the supply of air to exhaust gas present within the muffler 55 to burn unburned gas. [0032]
In the figure, numeral 61 denotes a handlebar cover, numeral 62 denotes a front cover, 63 a license plate, 64 a leg shield, 66 a tandem seat, 67 a body cover, 68 an aperture formed in the body cover 67, 71 a tail lamp, and 72 a rear fender. [0033]
Fig. 2 is a side view of the air cleaner according to the present invention (the arrow (FRONT) in the figure represents a vehicular front direction; this is true also in the following). The air cleaner 51 is provided with an air cleaner case 81. The air cleaner case 81 is made up of a case body 82 (not shown) disposed on the rear wheel 23 (see Fig. 1) side and an air cleaner cover 84, the air cleaner cover 84 being secured with plural machine screws 83 to the case body 82 at an outer side position of the vehicle body. [0034]
A drain pipe 82c is integral with the case body 82, the drain pipe 82c projecting downward for discharging oil present within a sub chamber formed in the air cleaner case 81 to the exterior. A drain piping 8 6 is connected to the drain pie 82c. Numerals 82a and 82b denote

mounting portions integral with the case body 82 for mounting the air
cleaner 51 to the power unit 22 (see Fig. 1).
[0035]
The drain piping 86 is made up of an L-shaped pipe 87 connected to the drain pipe 82c and which is L-shaped in side view, a connecting pipe 88 connected to an end of the L-shaped pipe 87, a drain hose 91 connected to the connecting pipe 88, and a drain cap 92 which plugs up a free end of the drain hose 91. The connecting pipe 88 is engaged with a piping support portion 82A formed at a lower portion of the case body 82. Connecting portions of the drain pipe 82c, L-shaped pipe 87, connecting pipe 88, drain hose 91 and drain cap 92 are each clamped with a hose band 93. [0036]
An intake duct 96 made of rubber for introducing the outside air into the air cleaner case 81 is attached to an upper portion of the air cleaner cover 84. The intake duct 96 is made up of a duct connecting portion 96a fitted in and connected to the air cleaner cover 84, an outer duct portion 96c extending to the vehicular front side from the duct connecting portion 96a and with an intake port 96b opening to the vehicular front side, and an inner duct portion 96e extending obliquely downward to the vehicular rear side within the air cleaner case 81 from the duct connecting portion 96a, the inner duct portion 96e having an exhaust port 96d. [0037]
Fig. 3 is a sectional view (a partial plan view) of the air cleaner according to the present invention. The air cleaner 51 is made up of the air cleaner case 81, a separator 101 mounted within the case body 82, and an air cleaner element 103 supported at one end thereof by

the separator 101 and secured at an opposite end thereof to the case body 82 with a machine screw 102. [0038]
The interior of the air cleaner case 81 is partitioned into an upstream side in the flow of air of the air cleaner element 103, i.e., a dirty side 51D extending from the intake duct 96 (see Fig. 2) up to the air cleaner element 103, and a downstream side in the flow of air of the air cleaner element 103, i.e., a clean side 51C extending from the air cleaner element 103 up to the connecting tube 48. [0039]
The case body 82 is integrally provided at a peripheral edge thereof with an annular recess 82B, while the air cleaner cover 84 is integrally provided at a peripheral edge thereof with an annular projection 84A. Thus, there is formed a combined, or mating, structure wherein the case body 82 and the air cleaner cover 84 are combined together, causing the annular recess 82B and the annular projection 84A to be fitted with each other. Numeral 81A denotes a mating surface between the case body 82 and the air cleaner cover 84, the mating surface 81A extending in the longitudinal direction of the vehicle. [0040]
The separator 101 is a flat plate-like part disposed near a connecting tube connection hole 82d which is formed in the case body 82 for connection of the connecting tube 48. A fitting recess 101a is formed in a peripheral edge of the separator 101 and an annular projection 82e formed on the case body 82 is fitted in the fitting recess 101a. In this state the separator 101 is mounted to the case body 82 with plural machine screws 104. Numeral 48a denotes an annular recess formed in the connecting tube 48 so as to be fitted in the

connecting tube connection hole 82d. [0041]
The connecting tube connection hole 82d and the annular recess 48a are constituent portions of a connecting tube connection 105. The separator 101 is disposed in opposition to both the connecting tube connection 105 and an end 48b of the connecting tube 48. [0042]
A flat space surrounded with the separator 101 and the case body 82 defines a sub chamber 106. A blow-by hose 107 communicating with the interior of a crankcase 38a (see Fig. 1) of the engine 38 is connected to the sub chamber 106 via a connecting port 82g. The sub chamber 106 functions as a catch tank which separates liquid oil from blow-by gas introduced from the interior of the crankcase 38a into the sub chamber 106 through the blow-by hose 107 and also functions as a resonator for diminishing an intake noise. [0043]
An element connecting hole 101b for connection of the air cleaner element 103 is formed in the separator 101 and a sealing member 111 made of rubber is fitted in the element connecting hole 101b. Further, a small-diameter portion 103a of the air cleaner element 103 is removably fitted in the sealing member 111 along an inner periphery surface Ilia of the sealing member. [0044]
The air cleaner element 103 is a part provided with frames 114 and 115 at both ends of a filter which has a generally elliptic outline. The frame 114 is formed with the small-diameter portion 103a and a bracket 116 attached to the frame 115 is secured with a machine screw 102 to a boss portion 82j which is integral with the case body 82.

Numeral 118 denotes a nut member which is internally threaded for threaded engagement therein of the machine screw 102 and which is embedded in the boss portion 82j. [0045]
Figs. 4 (a) to 4 (c) are explanatory diagrams of the drain piping and piping support portion according to the present invention.
Fig. 4(a) is an exploded sectional view of the drain piping-86. The L-shaped pipe 87 is a part made of rubber and comprising a vertical portion 87a extending vertically and a horizontal portion 87b extending horizontally from a lower end of the vertical portion 87a, the vertical portion 87a and the horizontal portion 87b being integral with each other. [0046]
The connecting pipe 88 includes a base portion 88a, a small-diameter pipe 88b and a large-diameter pipe 88c extending to both sides from the base portion 88a, and a flange portion 88e formed at an end of a neck portion 88d which is provided in the base portion 88a. [0047]
The drain hose 91 is a part made of rubber and the drain cap 92 is made up of a plug portion 92a to be inserted into an end portion of the drain hose 91 and a large-diameter portion 92b formed at an end of the plug portion 92a and having a diameter larger than that of the plug portion 92a.
The horizontal portion 87b, connecting pipe 88 and drain hoes 91 constitute a horizontal portion 86a of the drain piping 86. [0048]
An end of the vertical portion 87a of the L-shaped pipe 87 is

connected to the drain pipe 82c of the case body 82, the small-diameter portion 88b of the connecting pipe 88 is inserted into an end of the horizontal portion 87b of the drain pipe 82c, one end of the drain hose 91 is inserted into the large-diameter portion 88c of the connecting pipe 88, and the plug portion 92a of the drain cap 92 is inserted into an opposite end of the drain hose 91 to plug up the opposite end-
Oil stored in the drain piping 86 is discharged upon removal of the drain cap 92. [0049]
Fig. 4 (b) is a sectional view of the piping support portion 82A of the case body 82 which engages and holds the connecting pipe 88 (see Fig. 4(a)), taken along line 4-4 in Fig. 2.
The piping support portion 82A is a portion projecting horizontally inwards of the vehicle body and having a slit 82rn and downwardly projecting lugs 82r and 82s.
Fig. 4 (c) is a plan view of the piping support portion 82A. The piping support portion 82A has an expanded portion 82n within the slit 82m, [0050]
Figs- 5(a) to 5(d) are explanatory diagrams showing the connecting pipe according to the present invention.
Fig. 5(a) is a side view of the connecting pipe 88. The
connecting pipe 88 includes, in the neck portion 88d thereof, a pair of plane portions 88g and 88h (only one reference numeral 88g is shown) formed opposedly to each other in the surface-back direction of the figure and a vertically long projecting portion 88j formed under one plane portion 88g and projecting to this side.

Fig. 5(b) is a plan view of the connecting pipe 88. The plane portions 88g and 88h are formed in parallel with the extending direction of the small-diameter portion 88b and the large-diameter portion 88c. The projecting potion 88 j is formed so as to intersect the plane portions 88g and 88h perpendicularly. [0052]
In Fig. 5(c), for engaging and holding the connecting pipe 88 with respect to the case body 82, the large-diameter portion 88c of the connecting pipe 88 is directed toward the slit 82m of the piping support portion 82A and the neck portion 88d is inserted into the slit 82m as indicated with an arrow. At this time, since the distance between the plane portions 88g and 88h is smaller than the width of the slit 82m, the neck portion 88d can be inserted smoothly into the slit 82m. [0053]
For example, even when the small-diameter portion 88b is directed toward the slit 82m and an attempt is made to insert the neck portion 88d into the slit 82m, the projecting portion 88j of the connecting pipe 88 comes into abutment against the malassembly preventing lug 82r formed in the piping support portion 82A, thus obstructing the insertion, whereby a malassembly is prevented. [0054]
In Fig. 5(d), the neck portion 88d causes the connecting pipe 88 inserted into the slit 82m to rotate 90° counterclockwise. As a result, since the plane portions 88g and 88h are each in a 90° turned position with respect to the slit 82m, the neck portion 88d becomes incapable of being disengaged from the expanded portion 82n.

, The lug 82s functions as a stopper when the connecting pipe 88 is turned 90° or more. [0055]
The operation of the air cleaner 51 constructed as above will be described below.
Fig. 6 is a first operation diagram showing the operation of the air cleaner according to the present invention. Fig. 6 shows a state in which the air cleaner cover 84 (see Fig. 2) is removed from the air cleaner case 81 (see Fig. 2) and the air cleaner element 103 (see Fig. 3) is removed from the separator 101.
The separator 101 is secured to the front side of the case body 82 with plural machine screws 104. [0056]
Since the separator 101 is thus mounted substantially throughout the whole front portion of the case body 82, it is possible to enlarge the area of the separator 101 and hence possible to increase the volume of the sub chamber 106 (see Fig. 3) . [0057]
Fig. 7 is a second operation diagram showing the operation of the air cleaner according to the present invention, in which the separator 101 (see Fig. 6) is removed from case body 82 in comparison with the state of Fig. 6. Numeral 82p appearing in plural positions denote a screw engaging hole formed in the case body 82 for engagement therein of machine screws 104 (see Fig. 6).
By thus removing the separator 101 from the case body 82, an inner wall 106a of the sub chamber 106 is opened largely, so that for example a cleaning work for the interior of the sub chamber 106 can be done easily and it is possible to improve the workability.

Fig. 8 is a perspective view showing a body cover of the motorcycle according to the present invention. A triangular recess 67a is formed in a front portion of the body cover indicated at 67. Further, in a rear wall 67b of the recess 67 is formed an elongated aperture 67A along one side of the triangle, the aperture 67A being inclined at an upper end thereof to a greater extent than a lower end thereof. [0059]
The aperture 67A is formed centrally of the body cover 67 and above a rear end 31a of the step floor 31. Numeral 31b denotes a foot rest for a passenger sitting on a rear portion of the tandem seat 66 (see Fig. 1) and numeral 121 denotes a step under cover which covers the step floor 31 from below. [0060]
Fig. 9 is a perspective view showing a principal portion on the back side of the body cover of the motorcycle according to the present invention. A cover member 123 is mounted to the back side of the body cover 31 so as to cover a lower half of the aperture 67A. Further, a trough member 124 having a J-shaped section is mounted to the back side of a lower end of the body cover 67 in such a manner that one end thereof covers the cover member 123 from below. [0061]
The cover member 123 is formed with an inwards projecting wall 123a projecting inwards of the vehicle body.
For example, when rain water enters the inside of the body cover 67 through the aperture 67A, the rain water is received by an inner groove of the trough member 124 and is discharged from between the

trough member 124 and the inwards projecting wall 123a of the cover member 123, as indicated with an arrow. A pair of mounting portions formed on the cover member 123-for mounting the cover member to the body cover 67 are indicated at 123b. [0062]
As shown in Fig. 3 referred to above, in an air cleaner structure in the motorcycle 10 (see Fig. 1) wherein the interior of the air cleaner case 81 is partitioned by the air cleaner element 103 into the dirty side 51D and the clean side 51C and the sub chamber 106 is formed on the clean side 51C and is brought into communication with the interior of the crankcase 38a (see Fig. 1) of the engine 38 (see Fig. 1) through the blow-by hose 107, the present invention is firstly characterized in that the air cleaner case 81 has a combined structure comprising the case body 82 and the air cleaner cover 84 mating with the case body 82 and the air cleaner case 81 is flat in a direction orthogonal to the mating surface between the case body 82 and the air cleaner cover 84, the connecting tube 48 communicating with the engine 38 side is connected to the case body 82 so as to direct itself to a plane 81B passing the mating surface 81A, the separator 101 for forming the sub chamber 106 is attached removably to the case body 82 so as to cover the connection (connecting tube connection 105) of the connecting tube 48 to the case body 82 and so as to confront the end 48b of the connecting tube 48, and the air cleaner element 103 is cylindrical and is removably fitted in the element connecting hole 101b formed in the separator 101. [0063]
According to this construction, the sub chamber 106 also becomes flat in the direction orthogonal to the mating surface 81A, and by

removing the air cleaner cover 84 from the case body 82 and the air cleaner element 103 from the separator 101, further, by removing the separator 101 from the case body 82, the inner wall 106a of the sub chamber 106 is opened largely, so that for example in a cleaning work it becomes easy for a worker's hand to enter the whole interior of the sub chamber 106, thus permitting improvement of the workability. [0064]
If the separator 101 and the air cleaner element 103 are provided as an assembly, then by subassembling the separator 101 and the air cleaner element 103 in advance, it is possible to decrease the number of assembling steps on an assembly line and hence possible to improve the productivity. Consequently, it is possible to reduce cost of the air cleaner. [0065]
For example, by adopting such a shape of the separator 101 as swelled or depressed with respect to a flat plate, it is possible to change the volume of the sub chamber 106 and hence possible to change the clean side volume which exerts an influence on vehicular engine performance and drivability and the resonator volume which influences the intake noise. Moreover, the specification of the air cleaner element 103 can be changed by only a change made to the separator 101, thus making it possible to increase the design freedom of the air cleaner 51. [0066]
The present invention is secondly characterized in that the air cleaner 51 is disposed long in the longitudinal direction of the vehicle body and sideways of the rear wheel 23 (see Fig. 1) so as to straddle the rear cushion unit 24 for the rear wheel, the mating surface 81A

between the case body 82 and the air cleaner cover 84 is extended in the longitudinal direction of the vehicle body, the connecting tube 48 is connected to the case body 82 on the front side with respect to the rear cushion unit 24 and from the transversely central side of the vehicle body, and the separator 101 is disposed throughout the whole of the front side with respect to the rear cushion unit 24. [0067]
Thus, the air cleaner 51 is disposed sideways of the rear wheel 23 and long in the longitudinal direction of the vehicle body so as to straddle the rear cushion unit 24 for the rear wheel, the mating surface 81A between the case body 82 and the air cleaner cover 84 is extended in the longitudinal direction of the vehicle body, the connecting tube 48 is connected to the case body 82 on the front side with respect to the rear cushion unit 24 and from the transversely central side of the vehicle body, and the separator 101 is disposed throughout the whole of the front side. Therefore, not only the volume of the air cleaner 51 can be made large while suppressing the projection of the air cleaner 51 in the transverse direction of the vehicle body, but also the area of the separator 101 can be made large. Consequently, when the separator 101 is removed, the interior of the sub chamber 106 is opened largely, whereby not only the workability of for example a cleaning work for the sub chamber 106 can be further improved, but also the degree of freedom on the shape of the sub chamber 106 can be further increased. [0068]
The present invention is thirdly characterized in that the separator 101 is formed so as to surround the connecting tube connection 105 to the case body 82.

Therefore, the volume of the sub chamber 106 can be further enlarged by utilizing a dead space formed in the connecting tube connection 105, whereby it is possible to prevent an increase in size of the air cleaner 51. [0069]
The present invention is fourthly characterized in that the separator 101 is clamped to the case body 82 with plural machine screws 104, the machine screws 104 being disposed at positions not overlapping the air cleaner element 103 when seen axially of the air cleaner element.
Thus, even with the machine screws 104, the air cleaner element 103 does not overhang in the transverse direction of the vehicle body and it is possible to not only make the vehicle body compact but also make the vehicle width small. [0070]
The present invention is fifthly characterized in that the L-shaped drain piping 86 comprising the vertical portion 87a extending vertically and the horizontal portion 86a extending horizontally is connected to the sub chamber 106, the horizontal portion 86a being provided with the connecting pipe 88 as an engaging portion to be engaged with and held by the case body 82.
Therefore, even when force is exerted on the drain piping 86 during maintenance or upon vibration of the vehicle body, vibration of the drain piping 86 can be prevented by the connecting pipe 88. [0071]
The present invention is sixthly characterized in that, as shown in Figs. 2 and 4(a), the engaging portion is the connecting pipe 88 which serves as a connecting portion for connection between the L-shaped pipe 87 as an upstream portion of the drain piping 86 and

r
the drrain hose 91 as a downstream portion.
Since it is thus possible to divide the drain piping 86 into the L-shape pipe 87 and the drain hose 91, each part can be made short and hence the storage thereof in a factory and the transport thereof are easy. [0072]
Although in this embodiment the connecting pipe 88 as a connecting portion is provided separately from the L-shaped pipe 87 as an upstream portion and the drain hose 91 as a downstream portion, this constitutes no limitation. The connecting pipe 88 may be formed integrally with the L-shaped pipe 87 or the drain hose 91. [Industrial Applicability] [0073]
The air cleaner structure of the present invention is suitable for a motorcycle.
[Brief Description of the Drawings] [0074]
Fig. 1 is a side view of a motorcycle adopting an air cleaner structure according to the present invention.
Fig. 2 is a side view of an air cleaner according to the present invention.
Fig. 3 is a sectional view of the air cleaner according to the present invention.
Fig. 4 is an explanatory diagram of a drain piping and a piping support portion according, to the present invention.
Fig. 5 is an explanatory diagram showing a connecting pipe according to the present invention.
Fig. 6 is a first operation diagram showing the operation of

the air cleaner according to the present invention.
Fig. 7 is a second operation diagram showing the operation of the air cleaner according to the present invention.
Fig. 8 is a perspective view showing a body cover of a motorcycle according to the present invention.
Fig. 9 is a perspective view showing a principal portion of a back side of the body cover of the motorcycle according to the present invention.
[Explanation of Reference Numerals] [0075]
10 ... motorcycle. 24 ... rear cushion unit, 38 ... engine, 38a ... crankcase, 48 ... connecting tube, 51C ... clean side, 51D ... dirty side,
81 ... air cleaner case, 81A ... mating surface, 81B ... plane,
82 ... case body,
84 ... air cleaner cover,
86 ... drain pipe (drain piping), 86a ... horizontal portion,
87 ... upstream portion (L-shaped pipe) , 87a ... vertical portion,
88 ... engaging portion (connecting pipe) , 91 ... downstream portion (drain hose) ,

101 ..,. separator,
101b ... hole (element connecting hole),
103 ... air cleaner element,
104 ... machine screw,
105 ... connecting tube connection,
106 ... sub chamber,
107 ... blow-by hose.

[Name, of Document] Scope of Claims [Claim 1]
An air cleaner structure in a motorcycle in which the interior of an air cleaner case is partitioned by an air cleaner element into a dirty side and a clean side and a sub chamber is formed on the clean side and is brought into communication with the interior of a crankcase of an engine through a blow-by hose,
wherein: the air cleaner case has a combined structure including a case body and an air cleaner cover mating with the case body and the air cleaner case is flat in a direction orthogonal to a mating surface between the case body and the air cleaner cover;
a connecting tube communicating with the engine side is connected to the case body so as to direct itself to a plane passing the mating surface;
a separator for forming the sub chamber is attached removably to the case body so as to cover the connection of the connecting tube to the case body and so as to confront an end portion of the connecting tube; and
the air cleaner element is cylindrical and is removably fitted in a hole formed in the separator. [Claim 2]
The air cleaner structure in a motorcycle according to Claim
1.
wherein: the air cleaner is disposed long in a longitudinal direction of a vehicle body and sideways of a rear wheel so as to straddle
a rear cushion unit for the rear wheel;
the mating surface between the case body and the air cleaner cover extends in the longitudinal direction of the vehicle body;

. the connecting tube is connected to the case body on a front side with respect to the rear cushion unit and from a transversely central side of the vehicle body; and
the separator is disposed throughout the whole of the front side with respect to the rear cushion unit. [Claim 3]
The air cleaner structure in a motorcycle according to Claim
1 or Claim 2,
wherein the separator is formed so as to surround the connection of the connecting tube to the case body. [Claim 4]
The air cleaner structure in a motorcycle according to any of Claims 1 to 3,
wherein the separator is clamped to the case body with machine screws, the machine screws being disposed at positions not overlapping the air cleaner element when seen axially of the air cleaner element. [Claim 5]
The air cleaner structure in a motorcycle according to any of Claims 1 to 4,
wherein an L-shaped drain pipe comprising a vertical portion
extending vertically and a horizontal portion extending horizontally
is connected to the sub chamber, the horizontal portion being provided
with an engaging portion to be engaged with and held by the case body.
[Claim 6]
f

Documents:

221-CHE-2008 AMENDED CLAIMS 11-04-2012.pdf

221-CHE-2008 EXAMINATION REPORT REPLY RECEIVED 11-04-2012.pdf

221-CHE-2008 FORM-3 11-04-2012.pdf

221-CHE-2008 OTHER PATENT DOCUMENT 11-04-2012.pdf

221-che-2008-abstract.pdf

221-che-2008-claims.pdf

221-che-2008-correspondnece-others.pdf

221-che-2008-description(complete).pdf

221-che-2008-drawings.pdf

221-che-2008-form 1.pdf

221-che-2008-form 18.pdf

221-che-2008-form 26.pdf

221-che-2008-form 3.pdf

221-che-2008-form 5.pdf

abs-221-che-2008.jpg

« Previous Patent

Next Patent »

Patent Number

252703

Indian Patent Application Number

221/CHE/2008

PG Journal Number

22/2012

Publication Date

01-Jun-2012

Grant Date

28-May-2012

Date of Filing

28-Jan-2008

Name of Patentee

HONDA MOTOR CO., LTD.

Applicant Address

1-1, MINAMIAOYAMA 2-CHOME MINATO-KU, TOKYO

Inventors:

#	Inventor's Name	Inventor's Address
1	TOZAWA, HIDEAKI	C/O HONDA R&D CO LTD 4-1, CHUO 1-CHOME WAKO-SHI, SAITAMA 351-0193
2	MATSUZAKI, MASANOBU	C/O HONDA R&D CO LTD 4-1, CHUO 1-CHOME WAKO-SHI, SAITAMA 351-0193
3	MURAOKA, YUKI	C/O HONDA R&D CO LTD 4-1, CHUO 1-CHOME WAKO-SHI, SAITAMA 351-0193
4	NAKANO, JUNICHI	C/O HONDA R&D CO LTD 4-1, CHUO 1-CHOME WAKO-SHI, SAITAMA 351-0193

PCT International Classification Number

F02M35/16

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	2007-022129	2007-01-31	Japan