JP2016037191A - Saddle-riding type vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow work accuracy and efficiency to be improved when assembling a sprocket cover or when maintaining a sprocket and a transmission member wound around the sprocket.SOLUTION: The saddle-riding type vehicle is equipped with an engine case 11, a sprocket, an endless loop-like transmission member 26, a guide member 28 and a sprocket cover 31. The sprocket is fixed rotatably to one end part of an output shaft protruding in a vehicle width direction from the engine case 11. The endless loop-like transmission member 26 engages with a tooth part 18a of the sprocket and rotated in interlock with the sprocket so as to drive a wheel 3. The guide member 28 opposes to a site at which the transmission member 26 engages with the sprocket from outward in a radial direction and is fixed to a side wall part 11b of the engine case 11. The sprocket cover 31 is detachably attached to the guide member 28 and covers the sprocket from outward in the vehicle width direction.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a saddle riding type vehicle.

  In a straddle-type vehicle such as a motorcycle, a chain drive mechanism may be applied as a mechanism for transmitting power from a transmission to drive wheels. In this case, a sprocket cover is attached to the side wall of the case that houses the transmission (see, for example, Patent Document 1).

JP 2013-256248 A

  In the configuration shown in Patent Document 1, since the chain guide is disposed together with the sprocket cover when the chain guide is covered with the sprocket cover, the chain guide is located between the portion that meshes with the sprocket and the chain guide. It was difficult to arrange the chain guide while visually checking the clearance. In some cases, a belt is used instead of a chain as an endless loop-shaped transmission member for transmitting power from the transmission to the drive wheels.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to improve the accuracy and efficiency of work when assembling a sprocket cover or during work such as maintenance of a sprocket and a transmission member wound around the sprocket cover.

  A straddle-type vehicle according to an aspect of the present invention is engaged with a prime mover case, a sprocket that is rotatably fixed to one end portion of an output shaft that protrudes in the vehicle width direction from the prime mover case, and a tooth portion of the sprocket, An endless loop transmission member that rotates in conjunction with the sprocket to drive the wheel, and a guide that is opposed to the portion of the transmission member that meshes with the sprocket from the outside in the radial direction and is fixed to the side wall portion of the prime mover case And a sprocket cover that is detachably attached to the guide member and covers the sprocket from the outside in the vehicle width direction.

  According to the said structure, a guide member can be fixed to a motor case, visually recognizing the clearance between the site | part which meshes with the sprocket of a transmission member, and a guide member in the state in which the sprocket cover is not attached. Further, since the sprocket can be accessed by removing the sprocket cover from the guide member without removing the guide member from the prime mover case, the sprocket can be maintained while visually recognizing the positional relationship with the guide member. Therefore, the accuracy and efficiency of the work can be improved when the sprocket cover is assembled or when the transmission member or the sprocket is maintained.

  In the above form, the guide member has a case fixing portion fixed to the side wall portion, and a cover fixing portion for fixing the sprocket cover at a portion different from the case fixing portion, You may space apart from the said side wall part in the said vehicle width direction.

  According to the above configuration, since the cover fixing portion of the guide member is spaced apart from the side wall portion of the prime mover case in the vehicle width direction at a position different from the case fixing portion, the sprocket cover is fixed to the cover fixing portion. It is not fixed directly to the case. Accordingly, it is not necessary to secure a boss or the like for fixing the sprocket cover to the prime mover case in the sprocket cover or the prime mover case, and it is possible to prevent the sprocket cover or the prime mover case from increasing in size in the vehicle width direction.

  In the above aspect, the guide member may have an arc shape centered on a central axis of the sprocket, and the cover fixing portion may be formed at both ends in the circumferential direction of the guide member.

  According to the above configuration, the cover fixing portions are formed at both ends in the circumferential direction of the arc-shaped guide member, so that the sprocket covers attached to the guide member are fixed at both ends at positions corresponding to the respective cover fixing portions. Therefore, the sprocket cover can be stably attached to the guide member as compared with the case where the sprocket cover is fixed by the cover fixing portion formed only at one end portion of the guide member.

  In the above-described embodiment, a plurality of the case fixing portions and the cover fixing portions are respectively formed on the guide member, and at least one of the plurality of cover fixing portions is more than the at least one case fixing portion. May also be separated radially outward from the sprocket teeth.

  In order to prevent interference with the transmission member that meshes with the sprocket, the prime mover case has a narrow width in the vehicle width direction in some areas, ensuring a wall thickness for the fastening member that fixes the sprocket cover to be inserted. It is difficult to provide a boss. According to the said structure, a sprocket cover can be fixed in the position which does not interfere with a transmission member because the cover fixing | fixed part of a guide member is separated in the radial direction outer side from the tooth | gear part of a sprocket rather than the case fixing | fixed part.

  The said form WHEREIN: You may further provide the rivet member which fixes the said sprocket cover to the said cover fixing | fixed part so that attachment or detachment is possible.

  According to the said structure, size reduction and weight reduction of components can be achieved compared with the case where fastening members, such as a screw and a volt | bolt, are fixed to a cover fixing | fixed part using a rivet member. Furthermore, by using a rivet member, it is possible to prevent the pinching force from becoming excessive, and the fixing operation of the sprocket cover is facilitated.

  The said form WHEREIN: The screw fastening member which fixes the said sprocket cover to the member different from the said guide member is further provided, The said sprocket cover may further have the screw insertion part by which the said screw fastening member is penetrated.

  According to the said structure, in addition to the part fixed to a guide member by a rivet member, a sprocket cover also has a screw insertion part fixed to a member different from a guide member by a screw fastening member, By using a rivet member The sprocket cover can be fixed more stably by the screw fastening member while realizing the weight reduction of the parts.

  The said form WHEREIN: The said sprocket cover may have the extension part extended toward the said side wall part rather than a guide member in the upper part.

  According to the above configuration, since the gap between the upper portion of the sprocket cover and the side wall portion of the prime mover case is covered by the extension portion, the oil that lubricates the transmission member splatters from the transmission member that drives the sprocket to the top of the sprocket cover. In addition, it can be prevented that the sprocket cover is scattered from the gap between the upper portion of the sprocket cover and the side wall portion of the prime mover case.

  In the above embodiment, a push rod that passes through the inside of the input shaft that protrudes in the vehicle width direction from the prime mover case, a hydraulic cylinder that forms a flow path that transmits hydraulic pressure to a piston that presses the push rod, and the hydraulic cylinder A metal holder that is supported and fixed to the prime mover case, and the sprocket cover is made of resin and may be disposed so as to overlap the holder.

  According to the above configuration, the holder that supports the hydraulic cylinder that forms the hydraulic flow path for pressing the push rod by the piston is compared with the case where the holder is manufactured integrally with the sprocket cover by die casting for pressure resistance. Since the sprocket cover is molded from a resin material different from that of the metal holder and is disposed so as to overlap the holder separately, the sprocket cover can be reduced in weight and the manufacturing cost can be reduced. Further, for example, it is possible to improve maintenance workability by adopting a configuration in which the sprocket cover can be removed while the holder is fixed to the prime mover case.

  In the above aspect, the sprocket cover may have a notch at a front portion thereof, and the holder may be disposed so as to close the notch of the sprocket cover.

  According to the said structure, since a holder also plays the role which covers a sprocket, a holder and a sprocket cover can be laid out efficiently.

  In the above form, the rotation trajectory of the transmission member is an oval shape having a pair of upper and lower linear portions and a pair of front and rear semicircular portions continuous before and after the pair of linear portions, Of the pair of straight portions, the transmission member is disposed in a region intersecting with a virtual extension line forward of the straight portion that advances forward, and a peripheral portion at a position that overlaps the virtual extension line in a side view of the holder, The sprocket cover may be overlapped from the outside on the peripheral edge of the notch.

  According to the said structure, the peripheral part of the holder in the downstream of the advancing direction of a transmission member is piled up from the outer periphery with respect to the peripheral part of the notch part of the sprocket cover in the upstream of the advancing direction of a transmission member. Therefore, even if oil that lubricates the transmission member scatters along the virtual extension line due to centrifugal force in the region where the transmission member rotates from the straight portion to the semicircular portion, the gap between the holder and the sprocket cover Oil can be prevented from leaking outside.

  According to the present invention, it is possible to improve the accuracy and efficiency of work when assembling the sprocket cover, or during work such as maintenance of the sprocket and the transmission member wound around the sprocket cover.

1 is a left side view of a motorcycle that is an example of a saddle riding type vehicle according to an embodiment. FIG. 2 is an enlarged view around the sprocket cover of FIG. 1. It is the figure which removed the hydraulic cylinder, holder, and sprocket cover of FIG. It is the IV-IV sectional view taken on the line of FIG. It is a disassembled perspective view explaining attachment to the motor case of the holder of FIG. 1, a guide member, and a sprocket cover. It is a schematic sectional drawing which shows the positional relationship of the holder of FIG. 1, and a sprocket cover.

  Hereinafter, embodiments will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or corresponding element through all the figures, and the detailed description which overlaps is abbreviate | omitted. The concept of direction in the following description is based on the direction seen by the driver riding the saddle riding type vehicle. The vehicle width direction corresponds to the left-right direction.

[Configuration of motorcycle]
FIG. 1 is a left side view of a motorcycle 1 which is an example of a saddle riding type vehicle according to an embodiment. FIG. 2 is an enlarged view around the sprocket cover 31 of FIG. FIG. 3 is a view in which the hydraulic cylinder 21, the holder 23, and the sprocket cover 31 of FIG. 1 are removed. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is an exploded perspective view illustrating attachment of the holder 23, the guide member 28, and the sprocket cover 31 of FIG. In the following, description will be made with reference to FIGS.

  As shown in FIG. 1, the motorcycle 1 includes a front wheel 2 that is a driven wheel, a rear wheel 3 that is a driving wheel, and a vehicle body frame 4 that is disposed between the front wheel 2 and the rear wheel 3. The front wheel 2 is rotatably supported by a lower end portion of a front fork 5 that extends substantially in the vertical direction. A handle 6 extending left and right is attached to the upper end of the front fork 5 via a steering shaft 7. The rear wheel 3 is supported on the vehicle body frame 4 via a swing arm 8. The swing arm 8 is swingably supported by the vehicle body frame 4 at the front end thereof, and rotatably supports the axle 3a of the rear wheel 3 at the rear end thereof.

[Motor]
In the motorcycle 1, an engine (prime mover) 9 is mounted between the front wheels 2 and the rear wheels 3 as an example of a power source that rotationally drives the drive wheels. The engine 9 includes a cylinder block 10 in which a piston is reciprocally accommodated, and a crankcase 11 (prime motor case) connected to a lower end portion of the cylinder block 10. The crankcase 11 rotatably supports a crankshaft 12 extending in the vehicle width direction. A piston is connected to the crankshaft 12 via a connecting rod, and the piston reciprocates inside the cylinder block 10. The crankshaft 12 changes the reciprocating motion of the piston into a rotational motion. The rotation of the crankshaft 12 is transmitted to the rear wheel 3 via a transmission 15 and a transmission member 26 described later.

  In the present embodiment, the motorcycle 1 includes a parallel multi-cylinder engine as an example of the engine 9. In the motorcycle 1 equipped with a parallel multi-cylinder engine, a plurality of cylinders are arranged in the vehicle width direction. The crankcase 11 is divided into upper and lower parts that are vertically divided by a mating surface 11a of the crankcase 11 with the crankshaft 12 as the center (see FIG. 3), and is fixed integrally with bolts on the mating surface 11a. Since the crankcase 11 is divided vertically, the mating surface 11a is formed on the side wall portion 11b of the crankcase 11 as shown in FIG. The crankcase 11 is manufactured, for example, by die casting in which a molten metal (such as an aluminum alloy) is pressed into a mold and cast. In addition, the crankcase 11 in this embodiment is manufactured integrally with a case that rotatably supports the crankshaft 12 and a case that houses a transmission 15 described later.

  The engine 9 is connected to a transmission 15 for shifting its power and transmitting it to the rear wheels 3. The transmission 15 is accommodated in the crankcase 11. The transmission 15 has an input shaft 16 to which the rotation of the crankshaft 12 is transmitted, and an output shaft 17 to which the rotation of the input shaft 16 is transmitted via a transmission gear. One end portions (for example, left end portions) of the input shaft 16 and the output shaft 17 protrude from the crankcase 11 in the vehicle width direction. A sprocket 18 is fixed to one end of the output shaft 17. Thereby, the rotation of the crankshaft 12 is changed by the transmission 15 and output to the sprocket 18. In the following description, the sprocket 18 fixed to one end of the output shaft 17 is referred to as a drive sprocket 18. A plurality of teeth 18a are formed on the outer periphery of the drive sprocket 18 (see FIG. 3).

[clutch]
Incidentally, a clutch (not shown) is disposed inside the crankcase 11 on the right side of the vehicle body of the motorcycle 1. The clutch connects or disconnects the rotation of the crankshaft 12 to the transmission 15. In a motorcycle, a multi-plate clutch is generally housed in a crankcase 11. The multi-plate clutch transmits power with a plurality of overlapping clutch plates (clutch plates and friction plates). Specifically, the clutch is provided with a clutch spring, and in normal times, the clutch uses a clutch plate coupled to the crankshaft 12 by the force of the spring, and a pressure coupled to the input shaft 16 of the transmission 15. Press against the plate. Thus, the clutch connects the rotation of the crankshaft 12 to the transmission 15. In order to disengage the clutch, it is necessary to push the pressure plate in the direction opposite to the direction pressed by the clutch spring.

  The motorcycle 1 of the present embodiment has a mechanism that disconnects the clutch by hydraulic pressure. A clutch lever (not shown) is provided at the left end of the handle 6 in front of a grip held by the driver's left hand. The clutch lever is provided with a master cylinder that generates hydraulic pressure. When the driver holds the clutch lever, the hydraulic pressure generated from the master cylinder is sent to the hydraulic cylinder 21 via the hydraulic hose. The hydraulic cylinder 21 is fixed to the holder 23 by a plurality of first screw fastening members 22 (see FIG. 2). The holder 23 is fixed to the crankcase 11.

  A piston 24 is disposed inside the hydraulic cylinder 21. The hydraulic cylinder 21 is formed with a flow path for transmitting hydraulic pressure to the piston 24. The holder 23 is a metal member manufactured by die casting because of its pressure resistance.

  The piston 24 is connected to the other end of the push rod 25 that passes through the input shaft 16 shown in FIG. The piston 24 is actuated by the hydraulic pressure sent to the hydraulic cylinder 21, and the push rod 25 is pushed to the right, whereby the clutch is released. Thereby, the rotation of the crankshaft 12 transmitted to the transmission 15 is cut off. The clutch may be a single-plate clutch instead of a multi-plate clutch.

  A push rod 25 passing through the inside of the input shaft 16 of the crankcase 11 and the inside of the hydraulic cylinder 21 faces the chain 26 in the front-rear direction (see FIG. 5). Further, the outer periphery of the push rod 25 is covered with a cylindrical sleeve body 40. The sleeve body 40 is disposed between the crankcase 11 and the hydraulic cylinder 21 on the same axis as the push rod 25 and in the vehicle width direction. The sleeve body 40 has flanges 40a and 40b at both ends in the vehicle width direction.

  The crankcase 11 is formed with a fitting portion 11d that fits with the flange 40a of the sleeve body 40, and the hydraulic cylinder 21 is formed with a fitting portion 21a that fits with the flange 40b. In the present embodiment, a concave portion recessed inward in the vehicle width direction is formed in the side wall portion 11b of the crankcase 11 as the fitting portion 11d of the crankcase 11, and the fitting portion 21a of the hydraulic cylinder 21 serves as the fitting portion 21a of the hydraulic cylinder 21. A convex portion that protrudes inward in the vehicle width direction is formed on the side surface in the vehicle width direction.

  The outer periphery of the push rod 25 is covered with the sleeve body 40, and the flanges 40 a and 40 b of the sleeve body 40 are fitted into the fitting portion 11 d of the crankcase 11 and the fitting portion 21 a of the hydraulic cylinder 21. Even if foreign matter such as dust or water droplets adhering to the chain 26 facing in the front-rear direction is scattered by centrifugal force, the outer periphery of the push rod 25, the gap between the push rod 25 and the input shaft 16, the push rod 25 and the hydraulic cylinder 21 Is covered by the sleeve body 40, and foreign matter is prevented from entering the inside of the crankcase 11 and the inside of the hydraulic cylinder 21.

[Transmission member]
Next, transmission of the rotation output from the transmission 15 to the rear wheel 3 will be described. An endless loop transmission member 26 is engaged with the drive sprocket 18. In the present embodiment, the transmission member 26 is a chain. The chain 26 meshes with the tooth portion 18a of the drive sprocket 18 (see FIG. 3). The chain 26 rotates in conjunction with the drive sprocket 18. A driven sprocket 27 is attached to the axle 3 a of the rear wheel 3. The rotation of the drive sprocket 18 that is the rotation output from the transmission 15 is transmitted to the rear wheel 3 through the chain 26 and the driven sprocket 27. Thus, the chain 26 is wound between the drive sprocket 18 and the driven sprocket 27.

  As shown in FIG. 1, the rotation trajectory 200 of the chain 26 has an oval shape having a pair of upper and lower straight portions 200 a and 200 b and a pair of front and rear semicircular portions 200 c that are continuous before and after the pair of straight portions. The chain 26 is lubricated with lubricating oil to prevent wear and the like.

[Guide material]
The chain 26 may be stretched during the use process. Further, the tooth portion 18a of the drive sprocket 18 may be worn. When the teeth 26a of the chain 26 or the drive sprocket 18 are worn in this way, the chain 26 does not properly mesh with the teeth 18a of the drive sprocket 18, and the chain 26 gets over the teeth 18a of the drive sprocket 18 and from the drive sprocket 18. A detachment phenomenon may occur. In order to prevent this phenomenon, the guide member 28 is disposed to face the portion of the chain 26 that meshes with the drive sprocket 18 from the outside in the radial direction (see FIG. 3). In the following description, the guide member 28 is called a chain guide. The chain guide 28 has a substantially arc shape centered on the central axis of the drive sprocket 18. In the present embodiment, the chain guide 28 is a metal member.

  As shown in FIG. 3, the chain guide 28 includes a plurality of case fixing portions 28a, 28b, 28c fixed to the side wall portion 11b, and a sprocket cover 31 described later at a portion different from the case fixing portions 28a, 28b, 28c. A plurality of cover fixing portions 28d and 28e to be fixed are provided. The case fixing portion includes a first case fixing portion 28 a located at the upper portion of the chain guide 28, a second case fixing portion 28 b located at the front portion of the chain guide 28, and a third case located at the lower portion of the chain guide 28. And a fixing portion 28c.

  In order to fix the chain guide 28 to the side wall portion 11b, a second screw fastening member 29 (see FIG. 2) is inserted into the first case fixing portion 28a and the second case fixing portion 28b, and the third case fixing portion 28c is inserted into the third case fixing portion 28c. The third screw fastening member 30 is inserted. For example, the third screw fastening member 30 inserted through the third case fixing portion 28c is inserted through the boss portion 11c protruding outward in the vehicle width direction from the side wall portion 11b (see FIG. 4). A screw groove for screwing the third screw fastening member 30 is provided on the inner periphery of the boss portion 11c. Similarly, the second screw fastening member 29 inserted through the first case fixing portion 28a and the second case fixing portion 28b is also inserted through the boss portion of the side wall portion 11b.

  The cover fixing portion includes a first cover fixing portion 28d and a second cover fixing portion 28e that are respectively formed at both circumferential ends 28f and 28g of the chain guide 28. The first cover fixing portion 28d and the second cover fixing portion 28e are separated from the side wall portion 11b of the crankcase 11 in the vehicle width direction (see FIG. 4). The first cover fixing portion 28d is farther radially outward from the tooth portion 18a of the drive sprocket 18 than the first case fixing portion 28a. Further, the first cover fixing portion 28d is disposed behind the first case fixing portion 28a. Furthermore, one end portion 28f in the circumferential direction of the chain guide 28 on which the first cover fixing portion 28d is formed is disposed at a position overlapping the mating surface 11a of the crankcase 11 when viewed from the vehicle width direction.

[Sprocket cover]
A sprocket cover 31 that covers the drive sprocket 18 from the outside in the vehicle width direction is detachably attached to the chain guide 28. The sprocket cover 31 is molded from a resin material. The resin material of the sprocket cover 31 may be a fiber reinforced resin such as GFRP (Glass Fiber Reinforced Plastic). The sprocket cover 31 is attached to the first cover fixing portion 28 d and the second cover fixing portion 28 e of the chain guide 28 fixed to the crankcase 11 by the rivet member 32. In this way, the sprocket cover 31 is attached separately from the chain guide 28 when the vehicle body is assembled.

  The sprocket cover 31 is fixed to the holder 23 by a fourth screw fastening member 34. In the vehicle width direction, a collar 35 is disposed between the holder 23 and a portion (screw insertion portion 31d) through which the fourth screw fastening member 34 of the sprocket cover 31 is inserted (see FIG. 5). A fourth screw fastening member 34 is inserted through the collar 35.

  As shown in FIGS. 2 and 5, the sprocket cover 31 is inserted with a main body portion 31 a covering the drive sprocket 18, rivet fixing portions 31 b and 31 c through which the rivet member 32 is inserted, and a fourth screw fastening member 34. It has a screw insertion part 31d, an extension part 31e, and a notch part 31f. Portions other than the extension portion 31e of the sprocket cover 31 (main body portion 31a, rivet fixing portions 31b and 31c, screw insertion portion 31d, and notch portion 31f) are disposed on the outer side in the vehicle width direction than the chain guide 28.

  The rivet fixing portion 31b is provided at a position corresponding to the first cover fixing portion 28d, and the rivet fixing portion 31c is provided at a position corresponding to the second cover fixing portion 28e. In the present embodiment, the rivet member 32 is a resin push rivet. As shown in FIG. 4, the inner end portion of the rivet member 32 in the vehicle width direction is separated from the side wall portion 11 b of the crankcase 11 in the vehicle width direction. In addition to attaching the sprocket cover 31 to the chain guide 28 using a push rivet, for example, nut members such as welding nuts, rubber nuts, pop nuts, and the like are attached to the cover fixing portions 28d and 28e of the chain guide 28, The sprocket cover 31 may be attached to the chain guide 28 by screwing a bolt into the nut member.

  The extension part 31e extends from the rivet fixing part 31b located at the upper part of the sprocket cover 31, that is, the upper part of the main body part 31a, toward the side wall part 11b rather than the chain guide 28. The extension part 31e is provided with a guide part 31g extending toward the side wall part 11b so as to face the extension part 31e. The linear member 19 is wired between the extension part 31e and the guide part 31g. The guide portion 31 g guides the linear member 19 by holding the linear member 19 so as not to contact the chain 26.

  The linear member 19 is at least one of a sensor cable and a hydraulic tube. The sensor cable is, for example, a gear position sensor cable for detecting the shift position of the transmission 15, a cable for a side stand sensor for detecting the position of the side stand, and a shift operator when the shift position is changed by a driver's operation. It is at least one of a cable of a sensor such as a load cell (load sensor) that detects an applied load and a cable of a speed sensor that detects the number of rear wheel rotations. The hydraulic tube is, for example, a hydraulic tube that guides pressure oil as brake power to the rear wheel brake.

  The notch 31 f is notched in the front part of the sprocket cover 31, that is, the front part of the main body part 31 a so that the end on the drive sprocket 18 side is away from the drive sprocket 18. The notch 31f is arranged in a region intersecting the virtual extension line VL forward of the straight line portion 200a in which the chain 26 of the rotation locus 200 of the chain 26 advances forward.

  Further, the opening 31h is formed in the main body 31a at a position where the tooth 18a at a position different from the rotation locus 200 of the chain 26 among the teeth 18a of the drive sprocket 18 can be seen from the outside in the vehicle width direction. ing.

[Fixing the holder, chain guide and sprocket cover]
As shown in FIG. 5, the holder 23, the chain guide 28, and the sprocket cover 31 are fixed from the outside of the side wall portion 11 b of the crankcase 11. First, after the chain guide 28 is positioned with respect to the portion of the chain 26 that meshes with the drive sprocket 18 while visually recognizing the clearance, the third case fixing portion 28c of the chain guide 28 is moved to the side wall portion by the third screw fastening member 30. 11b. Thereafter, the holder 23 to which the hydraulic cylinder 21 is fixed by the first screw fastening member 22 is fixed to the side wall portion 11 b by the second screw fastening member 29. At that time, the second screw fastening member 29 is also inserted into the first case fixing portion 28 a and the second case fixing portion 28 b of the chain guide 28. That is, the second screw fastening member 29 fastens the holder 23 and the chain guide 28 together.

  After the holder 23 and the chain guide 28 are fixed to the side wall 11b, the sprocket cover 31 is attached to the chain guide 28 by the rivet member 32. The rivet member 32 is inserted through the first cover fixing portion 28d and the second cover fixing portion 28e. The sprocket cover 31 is also fixed to a holder 23 which is a member different from the chain guide 28 by a fourth screw fastening member 34. As shown in FIG. 2, the holder 23 is disposed so as to close the notch 31 f of the sprocket cover 31. When removing the sprocket cover 31 from the crankcase 11, the sprocket cover 31 is removed by removing the rivet member 32 and the fourth screw fastening member 34 with the holder 23 and the chain guide 28 attached to the crankcase 11. Remove from the chain guide 28.

  FIG. 6 is a schematic cross-sectional view showing the positional relationship between the holder 23 and the sprocket cover 31. As shown in FIGS. 2 and 6, the peripheral edge 23 a (hereinafter referred to as the peripheral edge 23 a of the holder 23) at a position overlapping the virtual extension line VL in the side view of the holder 23 is the peripheral edge of the notch 31 f of the sprocket cover 31. A portion 31i (hereinafter referred to as a peripheral portion 31i of the sprocket cover 31) is overlaid from the outside. In FIG. 6, the peripheral edge 23 a of the holder 23 is arranged with a gap from the peripheral edge 31 i of the sprocket cover 31, but there may be no gap.

  As described above, the rotation locus 200 of the chain 26 has an oval shape. The lubricating oil injected into the chain 26 moves along the same rotation locus in conjunction with the rotation of the chain 26. Here, in the region where the chain 26 moves from the straight portion 200a to the semicircular portion 200c of the rotation locus 200, the movement direction is changed, so that the oil that has moved the straight portion 200a before moving to the semicircular portion 200c. May scatter along the virtual extension line VL due to centrifugal force. However, as shown in FIG. 6, when the peripheral edge portion 23 a of the holder 23 is disposed so as to overlap the peripheral edge portion 31 i of the sprocket cover 31 from the outside, the clearance between the holder 23 and the sprocket cover 31 moves outward. The connecting path is formed in a direction opposite to the direction in which the oil scatters along the virtual extension line VL. Thereby, it is possible to prevent the oil scattered along the virtual extension line VL from leaking to the outside.

[effect]
The motorcycle 1 as an example of the saddle riding type vehicle configured as described above has the following effects.

  The sprocket cover 31 is fixed separately from the chain guide 28 when the vehicle body is assembled. Thereby, after fixing the chain guide 28 to the crankcase 11, the sprocket cover 31 can be detachably attached to the chain guide 28.

  As described above, the sprocket cover 31 is detachably attached to the chain guide 28 fixed to the crankcase 11, so that the chain 26 is engaged with the drive sprocket 18 of the chain 26 when the sprocket cover 31 is not attached. The chain guide 28 can be fixed to the crankcase 11 while visually checking the clearance between the guide 28 and the guide 28.

  Further, since the sprocket cover 31 can be removed from the chain guide 28 without removing the chain guide 28 from the crankcase 11, the drive sprocket 18 can be accessed. Maintenance is also possible. Accordingly, the accuracy and efficiency of the work can be improved when the sprocket cover 31 is assembled or when the drive sprocket 18 or the chain 26 is maintained.

  Furthermore, after fixing the chain guide 28 to the crankcase 11 separately from the sprocket cover 31, the sprocket cover 31 is attached to the chain guide 28, so that the chain guide 28 is fixed to the sprocket cover 31. Compared with the configuration in which 31 is attached to the crankcase 11, even if the dimensional tolerance of each component is large, the vehicle can be assembled after positioning the chain guide 28 with high accuracy.

  The cover fixing portions 28d and 28e of the chain guide 28 are separated from the side wall portion 11b of the crankcase 11 in the vehicle width direction at positions different from the case fixing portions 28a, 28b and 28c, and the sprocket cover 31 is covered with the cover fixing portions 28d and 28d. It is fixed to 28e and is not fixed to the crankcase 11. This eliminates the need to provide a boss portion for fixing the sprocket cover 31 to the crankcase 11 in the sprocket cover 31 or the crankcase 11, and prevents the sprocket cover 31 or the crankcase 11 from increasing in size in the vehicle width direction. Can do. Moreover, since it is not necessary to provide the boss | hub part in the crankcase 11, in the crankcase 11 manufactured by casting (die casting), the fluidity | liquidity of the molten metal (the molten metal poured into the metal mold | die) at the time of casting falls. This can be suppressed.

  Further, since the cover fixing portions 28d and 28e of the chain guide 28 are separated from the side wall portion 11b in the vehicle width direction, it is not necessary to provide a boss portion for fixing the sprocket cover 31 to the crankcase 11, so that the sprocket Even when the shape of the cover 31 is changed and the attachment position to the chain guide 28 is changed, the shape of the crankcase 11 remains the same and the cover fixing portions 28d and 28e of the chain guide 28 are formed. You only need to change the position. Therefore, it is not necessary to design and manufacture the crankcase 11 every time the mounting position of the sprocket cover 31 is changed, so that the cost can be reduced.

  The first cover fixing portion 28d or the second cover fixing portion 28e is formed at both ends 28f and 28g in the circumferential direction of the substantially arc-shaped chain guide 28, so that the sprocket cover 31 is connected to the first cover fixing portion 28d and the first cover fixing portion 28d. Since both ends are fixed at positions corresponding to the respective second cover fixing portions 28e, the sprocket cover 31 is more stable with respect to the chain guide 28 than when the sprocket cover 31 is fixed only to one cover fixing portion. Can be attached to.

  In order to prevent interference with the chain 26, the crankcase 11 has a narrow width in the vehicle width direction in a partial region (particularly the rear portion) of the crankcase 11 facing the chain 26 in the vehicle width direction. Therefore, at the rear part of the crankcase 11, it is difficult to provide a boss part that protrudes outward in the vehicle width direction so as to secure a wall thickness through which the fastening member is inserted. The first cover fixing portion 28d of the chain guide 28 is farther radially outward from the tooth portion 18a of the drive sprocket 18 than the first case fixing portion 28a. Thus, the first cover fixing portion 28d is radially away from the chain 26 that meshes with the tooth portion 18a of the drive sprocket 18, and the sprocket cover 31 can be fixed at a position that does not interfere with the chain 26.

  The first cover fixing portion 28d is disposed rearward of the first case fixing portion 28a. That is, the first cover fixing portion 28d is disposed at a position corresponding to the rear portion of the crankcase 11, so that the crank 26 may interfere with the chain 26. The sprocket cover 31 can be attached to the chain guide 28 without providing a boss portion for fixing the sprocket cover 31 at the rear part of the case 11.

  Further, since the crankcase 11 is divided vertically, a mating surface 11a is formed on the side wall portion 11b. When the boss portion having a thread groove is provided on the mating surface 11a, the boss portion is also vertically divided in the crankcase 11 divided vertically, so that when the crankcase 11 is fixed by the mating surface 11a, the thread groove is also formed. It must be aligned accurately, and workability deteriorates. In the present embodiment, one end portion 28f in the circumferential direction of the chain guide 28 where the first cover fixing portion 28d of the chain guide 28 is formed is provided at a position that overlaps the mating surface 11a when viewed from the vehicle width direction. Accordingly, since it is not necessary to provide a boss portion on the mating surface 11a, the fixing position of the sprocket cover 31 can be efficiently laid out, and workability can be improved.

  Further, the sprocket cover 31 has an extension part 31e extending from the rivet fixing part 31b positioned at the upper part thereof toward the side wall part 11b from the chain guide 28, so that the extension part 31e is connected to the upper part of the sprocket cover 31 and the side wall part. Since it covers the gap with 11b, even if the oil that lubricates the chain 26 scatters above the sprocket cover 31, it can be prevented from leaking outside. Further, the sprocket cover 31 other than the extension portion 31e (the main body portion 31a, the rivet fixing portions 31b and 31c, and the screw insertion portion 31d) is located outside the chain guide 28 in the vehicle width direction. Thereby, it can suppress that the dimension of the vehicle width direction of parts other than the extension part 31e enlarges, preventing the scattering of the oil to the exterior effectively.

  Further, by forming the opening 31h in the main body 31a of the sprocket cover 31, the shape of the tooth portion 18a of the drive sprocket 18 can be confirmed from the outside of the sprocket cover 31 while reducing the weight of the sprocket cover 31 ( (See FIG. 2). Furthermore, with a sprocket cover that does not have an opening such as the opening 31h, vibration noise generated by high-speed rotation of the drive sprocket and the chain disposed inside the sprocket cover when the motorcycle is running is not released to the outside. For this reason, a booming noise is generated inside the sprocket cover. However, by providing the opening 31h in the sprocket cover 31, the vibration noise is released to the outside, so that it is possible to prevent the occurrence of a booming noise.

  In addition, by fixing the sprocket cover 31 to the cover fixing portions 28d and 28e using the rivet member 32, it is possible to reduce the size and weight of the component as compared with the case where fastening members such as screws and bolts are used. it can. Furthermore, by using the rivet member 32 to fix the sprocket cover 31 to the cover fixing portions 28d and 28e, it is possible to prevent the pinching force from becoming excessive, and the fixing operation of the sprocket cover 31 is facilitated. In this embodiment, since the rivet member 32 is a resin push rivet, the fixing operation of the sprocket cover 31 becomes easier and the weight of the parts can be reduced.

  Further, the sprocket cover 31 is fixed to the holder 23 by the fourth screw fastening member 34 in addition to the portion fixed to the chain guide 28 by the rivet member 32, thereby reducing the weight of parts by using the rivet member 32. The sprocket cover 31 can be more stably fixed by being fixed to the holder 23 by the fourth screw fastening member 34 while realizing the above.

  The push rod 25 passing through the inside of the input shaft 16 of the crankcase 11 and the inside of the hydraulic cylinder 21 faces the chain 26 in the front-rear direction. In addition, a cylindrical sleeve body 40 is disposed between the crankcase 11 and the hydraulic cylinder 21 in the vehicle width direction on the same axis as the push rod 25. The sleeve body 40 covers the outer periphery of the push rod 25, and flanges 40 a and 40 b formed at both ends of the sleeve body 40 in the vehicle width direction are the fitting portion 11 d of the crankcase 11 and the fitting portion of the hydraulic cylinder 21. 21a is fitted. As a result, even if foreign matter such as dust or water droplets adhering to the chain 26 is scattered due to centrifugal force, the outer periphery of the push rod 25, the gap between the push rod 25 and the input shaft 16, and the gap between the push rod 25 and the hydraulic cylinder 21. Is covered with the sleeve body 40, it is possible to prevent foreign matter from entering the inside of the crankcase 11 and the inside of the hydraulic cylinder 21.

  Further, since the sprocket cover 31 is formed of a resin material different from that of the metal holder 23, the sprocket cover is integrated with the sprocket cover and manufactured by die casting for pressure resistance. Since 31 is separated from the holder 23 and is disposed so as to overlap the holder 23, the sprocket cover 31 can be reduced in weight and the manufacturing cost can be reduced. Further, for example, as a configuration in which the sprocket cover 31 can be removed while the holder 23 is fixed to the crankcase 11, maintenance workability can be improved.

  Further, since the holder 23 is arranged so as to close the notch 31f of the sprocket cover 31, the holder 23 also serves to cover the drive sprocket 18, and therefore the holder 23 and the sprocket cover 31 are efficiently laid out. be able to.

  Further, the peripheral edge portion 23a of the holder 23 on the downstream side in the traveling direction of the chain 26 is overlapped from the outside on the peripheral edge portion 31i of the notch portion 31f of the sprocket cover 31 on the upstream side in the traveling direction of the chain 26. Therefore, even if oil that lubricates the chain 26 scatters along the virtual extension line VL due to centrifugal force in the region where the chain 26 moves from the straight line portion to the semicircular portion, the holder 23 and the sprocket cover 31 Oil can be prevented from leaking outside through the gaps between them.

  In addition, this invention is not limited to embodiment mentioned above, The structure can be changed, added or deleted in the range which does not deviate from the meaning of this invention. In the above-described embodiment, the motorcycle including the engine 9 as the prime mover has been described. However, the prime mover is not limited to the engine and may be an electric motor, and the vehicle is not limited to the motorcycle 1, for example, ATV (All Terrain Vehicle: rough terrain vehicle), a small transport vehicle, and the like. In the above-described embodiment, the drive sprocket is fixed to the output shaft of the transmission 15. However, in a straddle-type vehicle not equipped with a transmission, the output shaft of the engine or electric motor that is the drive source is used. The drive sprocket may be fixed. In the above-described embodiment, a hydraulic clutch release (release) mechanism is mounted. However, a mechanical clutch release (release) mechanism that transmits operating force from the clutch lever by a wire or a rod is mounted. It may be.

  In the above-described embodiment, the chain 26 is wound around the drive sprocket 18 and the driven sprocket 27 as the transmission member 26, but a belt may be wound instead of the chain 26.

  The straddle-type vehicle according to the present invention has an excellent effect of improving work accuracy and efficiency during work such as assembly of a sprocket cover or maintenance of a transmission member or a sprocket. It is useful when applied widely to straddle-type vehicles that can demonstrate their significance.

1 Motorcycle (saddle-ride type vehicle)
3 Rear wheels
11 Crankcase (motor case)
11b Side wall portion 17 Output shaft 23 Holder 23a Peripheral portion 24 Piston 25 Push rod 18 Drive sprocket (sprocket)
18a Teeth 26 Chain (Transmission member)
28 Chain guide (guide member)
28a, 28b, 28c Case fixing part 28d, 28e Cover fixing part 28f, 28g Both ends in the circumferential direction 31 Sprocket cover 31e Extension part 31h Notch part 31i Peripheral part 32 Rivet member 34 Fourth screw fastening member 200 Rotation of chain (transmission member) Trajectory 200a, 200b Straight line part 200c Semicircle part VL Virtual extension line

Claims (10)

Prime mover case,
A sprocket rotatably fixed to one end of an output shaft protruding in the vehicle width direction from the motor case;
An endless loop transmission member that meshes with the sprocket teeth and rotates in conjunction with the sprocket to drive the wheels;
A guide member that is opposed to a portion of the transmission member that meshes with the sprocket from the outside in the radial direction and is fixed to a side wall portion of the prime mover case;
A straddle-type vehicle comprising: a sprocket cover that is detachably attached to the guide member and covers the sprocket from the outside in the vehicle width direction. The guide member has a case fixing part fixed to the side wall part, and a cover fixing part for fixing the sprocket cover at a part different from the case fixing part,
The straddle-type vehicle according to claim 1, wherein the cover fixing portion is separated from the side wall portion in the vehicle width direction. The guide member has an arc shape centered on a central axis of the sprocket,
The straddle-type vehicle according to claim 2, wherein the cover fixing portion is formed at each of both ends in the circumferential direction of the guide member. The case fixing portion and the cover fixing portion are each formed in a plurality on the guide member,
4. The saddle-riding type according to claim 2, wherein at least one of the plurality of cover fixing portions is spaced radially outward from the tooth portion of the sprocket with respect to the case fixing portion closest to the at least one. vehicle.   The straddle-type vehicle according to any one of claims 2 to 4, further comprising a rivet member that detachably attaches the sprocket cover to the cover fixing portion. A screw fastening member for fixing the sprocket cover to a member different from the guide member;
The straddle-type vehicle according to claim 5, wherein the sprocket cover further includes a screw insertion portion through which the screw fastening member is inserted.   The straddle-type vehicle according to any one of claims 1 to 6, wherein the sprocket cover has an extension portion extending toward the side wall portion rather than the guide member at an upper portion thereof. A push rod passing through the inside of the input shaft protruding in the vehicle width direction from the prime mover case;
A hydraulic cylinder that forms a flow path for transmitting hydraulic pressure to a piston that presses the push rod;
A metal holder that supports the hydraulic cylinder and is fixed to the prime mover case;
The straddle-type vehicle according to any one of claims 1 to 7, wherein the sprocket cover is made of resin and is disposed so as to overlap the holder. The sprocket cover has a notch in its front part,
The straddle-type vehicle according to claim 8, wherein the holder is disposed so as to close the notch of the sprocket cover. The rotation trajectory of the transmission member is an oval shape having a pair of upper and lower linear portions and a pair of front and rear semicircular portions continuous before and after the pair of linear portions,
The notch portion is arranged in a region intersecting with a virtual extension line to the front of the straight portion in which the transmission member proceeds forward among the pair of straight portions,
The straddle-type vehicle according to claim 9, wherein a peripheral portion at a position overlapping the virtual extension line in a side view of the holder is overlapped with a peripheral portion of the cutout portion of the sprocket cover from the outside.

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