JP2018167685A - Straddle-type vehicle - Google Patents

Abstract

To provide a straddle-type vehicle in which a power unit provided with an internal combustion engine and an air-cooling belt-type continuously variable transmission is arranged between a front wheel and a rear wheel and mounted on a vehicle body frame and which enables downsizing of the power unit by allowing the belt-type continuously variable transmission to be effectively cooled with the use of travel wind and increases maintainability of the belt-type continuously variable transmission.SOLUTION: A drive pulley 57 is provided at a front end portion of a crank shaft 27 extending in a vehicle front-to-back direction. A pulley shaft 60 on which a driven pulley 58 is provided includes an axis in parallel with the crank shaft 27, and the pulley shaft 60 is arranged at one side in a vehicle width direction of the crank shaft 27. A transmission case 21 in which a belt-type continuously variable transmission 48 is housed is continuously provided at an engine body 20 of an internal combustion engine E. A travel wind intake opening communicating with the transmission case 21 is opened to the front in the vehicle front-to-back direction to allow travel wind to be taken from the front in the vehicle front-to-back direction into the opening.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a vehicle body frame in which a power unit including an internal combustion engine and an air-cooled belt-type continuously variable transmission in which an endless belt is wound around a driving pulley and a driven pulley is disposed between a front wheel and a rear wheel. And a saddle-ride type vehicle in which the internal combustion engine is supported by the vehicle body frame with the axis of a crankshaft along the longitudinal direction of the vehicle.

  A large motorcycle in which a power unit including an internal combustion engine having an axis line of a crankshaft along the longitudinal direction of the vehicle and an oil-cooled belt-type continuously variable transmission is mounted on a body frame is known from Patent Document 1, Further, Patent Document 2 discloses a small motorcycle in which a power unit including an internal combustion engine having an axis line of a crankshaft along the vehicle width direction and an air-cooled belt type continuously variable transmission is mounted on a body frame.

Japanese Patent No. 4627059 JP 59-164226 A

  By the way, in the power unit disclosed in Patent Document 1, an oil-cooled belt-type continuously variable transmission is disposed below a crankshaft having an axis along the vehicle longitudinal direction. The structure of such a power unit is as follows. It is impossible to apply to a small motorcycle in which an air-cooled belt type continuously variable transmission is part of a power unit. On the other hand, in the one disclosed in Patent Document 2, the internal combustion engine is mounted on the vehicle body frame so that the axis of the crankshaft is along the vehicle width direction, and in the transmission case that houses the belt type continuously variable transmission, Since air from another air cleaner, which is a separate body from the air cleaner constituting a part of the intake system of the internal combustion engine, is introduced as cooling air, a power unit is required because a space for arranging the other air cleaner is required. Will become larger.

  The present invention has been made in view of such circumstances, and the belt-type continuously variable transmission can be miniaturized by effectively cooling the belt-type continuously variable transmission using traveling wind. The object is to provide a saddle-ride type vehicle with improved maintainability.

  In order to achieve the above object, the present invention provides a power unit comprising an internal combustion engine and an air-cooled belt type continuously variable transmission in which an endless belt is wound around a drive pulley and a driven pulley. In a saddle-ride type vehicle that is mounted on a vehicle body frame while being arranged between wheels, and the internal combustion engine is supported by the vehicle body frame with the axis of a crankshaft along the vehicle longitudinal direction, the drive pulley is arranged in the vehicle longitudinal direction. A pulley shaft provided at a front end portion of the crankshaft and provided with the driven pulley is disposed on one side in the vehicle width direction of the crankshaft while having an axis parallel to the crankshaft, and the belt type continuously variable transmission Is connected to the engine body of the internal combustion engine, and the running wind intake opening leading to the inside of the transmission case To be opened so as to face the front-rear direction front vehicle as possible to incorporate travel wind from direction forward to the first feature.

  In addition to the configuration of the first feature of the present invention, the engine body is mounted on the vehicle body frame in a posture in which a cylinder portion constituting a part thereof is inclined toward the driven pulley in the vehicle width direction, A second feature is that an air cleaner disposed above the cylinder portion and an intake pipe connected to the cylinder portion are connected in the vertical direction.

  According to the third aspect of the present invention, in addition to the configuration of the first or second feature, a cooling fin is provided on the outer surface of the cylinder portion, and the inside of the shroud covering the cylinder portion is communicated with the transmission case. It is characterized by.

  In addition to any of the configurations of the first to third features, the present invention provides a front portion of the transmission case along the vehicle front-rear direction at a portion located on the opposite side of the pulley shaft with respect to the crankshaft. A fourth feature is that a gear ratio control electric motor that can change a winding diameter of the belt around the drive pulley is provided.

  According to the present invention, in addition to any one of the first to fourth features, a lower end portion of the suction duct having the traveling wind intake opening portion at the upper end portion and extending in the vertical direction is connected to the transmission case. This is a fifth feature.

  In the present invention, in addition to any one of the first to fifth features, the power unit is interposed between an output shaft having an axis parallel to the pulley shaft, and the pulley shaft and the output shaft. A sixth feature is that a front end portion of a drive shaft that includes a gear mechanism and extends in the vehicle front-rear direction so as to transmit power to the rear wheel side is coupled to the output shaft.

  According to the present invention, in addition to any of the configurations of the first to sixth features, an exhaust pipe connected to one side wall of the cylinder portion in the vehicle width direction has a vehicle width in the vehicle front-rear direction rearward of the cylinder portion. A seventh feature is that the exhaust pipe is connected to an exhaust muffler disposed on the other side in the vehicle width direction of the rear wheel.

  According to the first feature of the present invention, a belt-type waste transmission is disposed at the front of a power unit having an internal combustion engine with a crankshaft along the vehicle longitudinal direction, and the running wind that opens toward the front in the vehicle longitudinal direction is opened. Since the intake opening communicates with the transmission case that houses the belt-type waste transmission, the belt-type continuously variable transmission is effectively cooled using the traveling wind to improve the life of the belt-type continuously variable transmission. It is possible to reduce the size of the power unit by eliminating the need for an air cleaner dedicated to the belt type continuously variable transmission, and the belt type continuously variable transmission is arranged at the front of the power unit. The maintenance of the transmission can be facilitated and the maintainability can be improved.

  Further, according to the second feature of the present invention, the cylinder portion of the engine body is inclined toward the driven pulley disposed on one side in the vehicle width direction of the crankshaft, and an air cleaner disposed above the cylinder portion, Since the intake pipe is connected in the vertical direction, it is not necessary to widen the vertical distance between the air cleaner and the engine body, and a space for arranging the intake pipe extending vertically can be secured.

  According to the third feature of the present invention, the cooling air can be guided from the transmission case side into the shroud covering the cylinder portion provided with the cooling fin on the outer surface, thereby effectively cooling the cylinder portion with air.

  According to the fourth aspect of the present invention, the speed ratio control electric motor is disposed at the front of the transmission case at a position opposite to the pulley shaft with respect to the crankshaft. It can be effectively cooled by the running wind.

  According to the fifth aspect of the present invention, since the running wind intake opening is formed at the upper end portion of the suction duct extending upward from the transmission case, dust, muddy water, etc. wound up by the front wheels enter the transmission case. Can be suppressed as much as possible.

  According to the sixth aspect of the present invention, the output shaft is coupled via the gear mechanism to the pulley shaft disposed on one side in the vehicle width direction of the crankshaft while having an axis parallel to the crankshaft, and the position of the output shaft Can be arranged at a relatively low position to contribute to the downsizing of the saddle-ride type vehicle.

  Further, according to the seventh feature of the present invention, the exhaust pipe is piped so that a part of the exhaust pipe extends in the vehicle width direction behind the cylinder portion of the engine body, thereby sufficiently taking measures against heat of the exhaust pipe. It is possible to improve the handling while performing.

1 is a left side view of a motorcycle. It is a 2 arrow front view of FIG. FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 2.

  Embodiments of the present invention will be described with reference to FIGS. In the following description, the top, bottom, left and right, and front and rear refer to directions as viewed from the occupant riding the motorcycle.

  First, in FIG. 1 and FIG. 2, a front fork 11 and a steering handle 12 that pivotally support a front wheel WF are supported on a front end portion of a body frame F of a motorcycle that is a saddle-ride type vehicle so that steering is possible. A power unit P that exerts power for driving the WR is mounted on the vehicle body frame F so as to be disposed between the front wheel WF and the rear wheel WR. The vehicle body frame F supports a fuel tank 13 disposed above the power unit P and a riding seat 14 disposed behind the fuel tank 13.

  The vehicle body frame F has a pair of left and right pivot frames 15 extending up and down behind the power unit P and in front of the rear wheel WR, and a swing arm 16 that pivotally supports the rear wheel WR at a rear end portion. A front end portion is supported on the pivot frame 15 via a support shaft 17 so as to be swingable up and down, and a rear cushion unit 18 is provided between the swing arm 16 and the vehicle body frame F.

  The swing arm 16 has a left arm 16a extending in the front-rear direction on the left side of the rear wheel WR, and the right side of the rear wheel WR in the front-rear direction while sandwiching the rear wheel WR between the left arm 16a. And a drive shaft 19 for transmitting the power from the power unit P to the rear wheel WR is accommodated in the left arm portion 16a.

  2 and 3 together, the power unit P includes an air-cooled internal combustion engine E and a transmission device M that transmits the output of the internal combustion engine E to the rear wheel WR. The internal combustion engine E is housed in a transmission case 21 connected to the engine body 20.

  The engine body 20 has a crankcase 22 that rotatably supports a crankshaft 27 having an axis extending in the vehicle longitudinal direction, and a cylinder bore 29 that slidably fits a piston 28, and is coupled to the crankcase 22. A cylinder body 23, a cylinder head 24 coupled to the cylinder body 23, and a head cover 25 coupled to the cylinder head 24.

  The cylinder body 23 and the cylinder head 24 constitute a cylinder portion 26 of the engine main body 20, and the engine main body 20 uses the cylinder axis C of the cylinder portion 26, that is, the axis of the cylinder bore 29 in the vehicle width direction. And mounted on the vehicle body frame F with the left side inclined.

  The piston 28 is connected to the crankshaft 27. A combustion chamber 30 that faces the top of the piston 28 is formed between the cylinder body 23 and the cylinder head 24.

  A generator 31 is connected to a rear end portion of the crankshaft 24 along the vehicle front-rear direction, and the generator 31 is coupled to the rear side wall of the crankcase 22. In addition, a valve operating mechanism 33 for opening and closing an intake valve and an exhaust valve disposed in the cylinder head 24 so as to be capable of opening and closing is accommodated between the cylinder head 24 and the head cover 25. A timing transmission mechanism 36 having a cam chain 35 is provided between a camshaft 34 constituting a part of the mechanism 33 and a rear portion of the crankshaft 27 along the vehicle front-rear direction.

  An air intake device 38 for supplying air to the combustion chamber 30 is disposed above the engine body 20 so as to be covered with the fuel tank 13 and is supported by the vehicle body frame F, and A throttle body 40 disposed between the air cleaner 39 and the engine body 20, a connecting tube 41 connecting the throttle body 40 and the air cleaner 39, a right side wall of the cylinder head 24 in the cylinder portion 26, and the throttle body 35 and an intake pipe 42 extending vertically. That is, the air cleaner 39 disposed above the cylinder portion 26 and the intake pipe 42 connected to the cylinder portion 26 are connected in the vertical direction.

  An exhaust device 43 for exhausting exhaust gas from the combustion chamber 30 is connected to the left side wall of the cylinder head 27, and the exhaust device 43 is connected to the left side wall of the cylinder head 24. And an exhaust muffler 45 disposed on the right side of the rear wheel WR so as to be connected to the downstream end of the exhaust pipe 44, and the exhaust pipe 44 is disposed on the rear side in the vehicle front-rear direction of the cylinder portion 26. It is piped so as to extend in the vehicle width direction. That is, the intermediate part 44a of the exhaust pipe 44 extends in the vehicle width direction behind the cylinder part 26 in the vehicle front-rear direction, and the exhaust pipe 44 is bent and formed so as to have such an intermediate part 44a. .

  The transmission device M housed in the transmission case 21 so as to transmit the rotational power of the crankshaft 27 to the rear wheel WR side is a belt type that continuously changes the rotational power transmitted from the crankshaft 27. A continuously variable transmission 48 and a gear mechanism 49 that decelerates and transmits the rotational power of the belt-type continuously variable transmission 48 to the drive shaft 19 are provided.

  The transmission case 21 is integrally connected to the left side wall of the crankcase 25 and covers the case main body 52 extending to the left side in the vehicle width direction and the belt type continuously variable transmission 48 from the front along the vehicle longitudinal direction. In this way, the case cover 53 is fastened to the case main body 52 and the gear cover 54 is fastened to the case main body 52 from the rear along the vehicle front-rear direction. A transmission chamber 55 for accommodating the belt type continuously variable transmission 48 is formed between the case main body 52 and the case cover 53, and the gear mechanism 49 is accommodated between the case main body 52 and the gear cover 54. A gear chamber 56 is formed.

  The belt type continuously variable transmission 48 is provided on a drive pulley 57 provided with a variable belt winding diameter at a front end portion of the crankshaft 24 along the vehicle longitudinal direction, and a pulley shaft 60 accommodated in the transmission case 21. A driven pulley 58 and an endless V-belt 59 wound around the driving pulley 57 and the driven pulley 58. The pulley shaft 60 provided with the driven pulley 58 is arranged on one side in the vehicle width direction of the crankshaft 27 while having an axis parallel to the crankshaft 27. In this embodiment, The pulley shaft 60 is disposed on the left side in the vehicle width direction of the crankshaft 27, and the engine body 20 is mounted on the vehicle body frame F with the cylinder portion 26 inclined to the driven pulley 58 side, that is, the left side in the vehicle width direction. Is done.

  The drive pulley 57 includes a fixed sheave 61 fixed to the crankshaft 27 and a movable sheave supported on the crankshaft 27 so as to be close to and away from the fixed sheave 61 in a direction along the axis of the crankshaft 27. 62. The movable sheave 62 is disposed closer to the crankcase 25 than the fixed sheave 61.

  The movable sheave 62 is a gear ratio variable means 64 operated by a gear ratio control electric motor 63, and changes the winding diameter of the V belt 59 around the drive pulley 57 in the axial direction of the crankshaft 27. Driven by.

  The gear ratio variable means 64 includes a cylindrical screw shaft 89 that is rotatably supported by the movable sheave 62 so as not to move in the axial direction, an output shaft 90 of the gear ratio control electric motor 63, and the screw shaft. And a reduction gear mechanism 91 interposed between the movable sheave 62 and the crankcase 22 so as to be accommodated in the transmission chamber 55.

  The transmission ratio control electric motor 63 is disposed at a front portion of the transmission case 21 along the vehicle front-rear direction at a portion located on the opposite side of the crankshaft 27 from the pulley shaft 60. As clearly shown in FIG. 2, the output shaft 90 that is directed backward in the vehicle front-rear direction on the opposite side of the pulley shaft 60 with respect to the vertical plane PL including the axis of the crankshaft 27, that is, on the right side of the vertical plane PL. The transmission case 21 is disposed on the upper front surface of the case cover 53 so as to enter the transmission chamber 55.

  The driven pulley 58 includes a fixed sheave 65 that is rotatably supported by the pulley shaft 60 and a movable sheave 66 that can move toward and away from the fixed sheave 65. The fixed sheave 65 and the movable sheave 66 A V-belt 59 is wound around. A torque cam mechanism 67 is provided between the fixed sheave 65 and the movable sheave 66. The movable sheave 66 is elastically biased toward the fixed sheave 65 by a coil spring 68, and between the fixed sheave 65 and the pulley shaft 60. A centrifugal clutch 69 is provided.

  The axial distance between the fixed sheave 65 and the movable sheave 66 in the driven pulley 58 is the axial force generated by the torque cam mechanism 67, the axial elastic force generated by the coil spring 68, the fixed sheave 65 and the movable sheave 66. As determined by the balance with the force from the V-belt 59 acting in the direction of the interval between them, the wrapping radius of the V-belt 59 around the driven pulley 58 increases as the wrapping radius of the V-belt 59 around the driving pulley 57 increases. Becomes smaller.

  Both end portions of the pulley shaft 60 penetrating the case main body 52 in a liquid-tight manner are rotatably supported by the case cover 53 and the gear cover 54. The output shaft 70 of the transmission device 21 has an axis parallel to the pulley shaft 60 and is rotatably supported by the case main body 52 and the gear cover 54 in the transmission case 21. It penetrates in a liquid-tight and rotatable manner and protrudes rearward from the transmission case 21 along the vehicle longitudinal direction.

  The gear mechanism 49 is interposed between the pulley shaft 60 and the output shaft 70, and includes a drive gear 71 provided integrally with the pulley shaft 60, and a final gear 72 provided on the output shaft 70. And first and second idle gears 73 and 74 disposed between the drive gear 71 and the final gear 72.

  A front end portion of the drive shaft 19 is connected via a universal joint 75 to a rear end portion of the output shaft 70 along the vehicle longitudinal direction. The rear end of the drive shaft 19 is connected to the axle 78 of the rear wheel WR via a universal joint 76 and a bevel gear mechanism 77 as shown in FIG.

  The internal combustion engine E is an air-cooled type, and a plurality of cooling fins 80 and 81 are provided on the outer surface of the cylinder portion 26 of the engine body 20, that is, on the outer surfaces of the cylinder body 23 and the cylinder head 24. In addition, the cylinder portion 26 is covered with a shroud 82 that communicates with the transmission chamber 55 in the transmission case 21, and an insertion hole 84 through which a spark plug 83 attached to the front portion of the cylinder head 24 is inserted. 82.

  The belt type continuously variable transmission 48 is also of an air cooling type, and a fan 86 for circulating air into the transmission chamber 55 that houses the belt type continuously variable transmission 48 is provided in the drive pulley 57. An opening 87 corresponding to the fan 86 is formed integrally with the fixed sheave 61, and is formed by a bottomed cylindrical tube portion 88 that protrudes from the outer surface of the case cover 53 and closes the outer end. .

  The opening 87 is adapted to receive a traveling wind accompanying the traveling of the motorcycle, and a traveling wind intake opening 89 that leads to the transmission chamber 55 of the transmission case 21 through the opening 87. The vehicle wind can be taken in from the front in the front-rear direction of the vehicle and is opened facing the front in the front-rear direction of the vehicle.

  The traveling wind intake opening 89 has a suction duct 90 extending in the vertical direction at the upper end, and the lower end of the suction duct 90 is an upper portion of the cylindrical portion 88 of the case cover 53 in the transmission case 21. Connected to.

  Next, the operation of this embodiment will be described. The internal combustion engine E is supported by the vehicle body frame F with the axis of the crankshaft 27 along the longitudinal direction of the vehicle, and the drive pulley 57 of the belt type continuously variable transmission 48 is secured to the longitudinal direction of the vehicle. The pulley shaft 60 provided at the front end portion of the crankshaft 27 in the direction and provided with the driven pulley 58 has one axis parallel to the crankshaft 27 and one side in the vehicle width direction of the crankshaft 27 (this embodiment The transmission case 21 that houses the belt type continuously variable transmission 48 is connected to the engine body 20 of the internal combustion engine E, and the running wind intake opening 89 communicates with the transmission case 21. However, it is possible to take in the traveling wind from the front of the vehicle in the front-rear direction and the front is opened in front of the front-rear direction of the vehicle. The continuously variable transmission 48 can be effectively cooled to improve the life of the belt-type continuously variable transmission 48, and the air cleaner dedicated to the belt-type continuously variable transmission 48 is not required, and the power unit P can be downsized. In addition, since the belt-type continuously variable transmission 48 is disposed at the front portion of the power unit P, the maintenance of the belt-type continuously variable transmission 48 can be facilitated and the maintainability can be improved.

  The engine body 20 is mounted on the vehicle body frame F in a posture in which a cylinder portion 26 constituting a part thereof is inclined toward the driven pulley 58 side (left side in this embodiment) in the vehicle width direction, and the cylinder portion 26 and the intake pipe 42 connected to the cylinder portion 26 are connected in the vertical direction, so that it is unnecessary to increase the vertical distance between the air cleaner 39 and the engine body 20 and extend up and down. An arrangement space for the intake pipe 42 can be secured.

  Further, cooling fins 80 and 81 are provided on the outer surface of the cylinder part 26, and the inside of the shroud 82 covering the cylinder part 26 is communicated with the transmission case 21, so that the cooling air is introduced into the shroud 82 from the transmission case 21 side. Thus, the cylinder portion 26 can be effectively air-cooled.

  In addition, the winding diameter of the V belt 59 around the drive pulley 57 is changed to the front portion of the transmission case 21 along the vehicle front-rear direction at a portion located on the opposite side of the crankshaft 27 from the pulley shaft 60. Since the gear ratio control electric motor 63 that is made possible is disposed, the gear ratio control electric motor 63 can be effectively cooled by the running wind.

  Further, since the lower end portion of the suction duct 90 having the running wind intake opening 89 at the upper end portion and extending in the vertical direction is connected to the transmission case 21, dust, muddy water or the like wound up by the front wheel WF is transmitted. It is possible to suppress the entry into 21 as much as possible.

  The power unit P includes an output shaft 70 having an axis parallel to the pulley shaft 60, and a gear mechanism 49 interposed between the pulley shaft 60 and the output shaft 70, and transmits power to the rear wheel WR side. Thus, since the front end portion of the drive shaft 19 extending in the vehicle longitudinal direction is connected to the output shaft 70 via the universal joint 75, the position of the output shaft 70 is arranged at a relatively low position to reduce the size of the motorcycle. It can contribute to the conversion.

  Furthermore, an exhaust pipe 44 connected to the side wall of the cylinder portion 26 in the vehicle width direction (left side in this embodiment) is piped so as to extend in the vehicle width direction behind the cylinder portion 26 in the vehicle front-rear direction. Since it is connected to the exhaust muffler 45 disposed on the other side in the vehicle width direction of the rear wheel WR (right side in this embodiment), it is possible to improve the handling performance while taking sufficient measures against heat of the exhaust pipe 44. .

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. Is possible.

  For example, the present invention is not limited to the motorcycle according to the above-described embodiment, but can be applied to other saddle-side vehicles such as a front two-wheeled motor tricycle and a rear two-wheeled motor tricycle.

DESCRIPTION OF SYMBOLS 19 ... Drive shaft 20 ... Engine main body 21 ... Transmission case 26 ... Cylinder part 27 ... Crankshaft 39 ... Air cleaner 42 ... Intake pipe 44 ... Exhaust pipe 45 ... Exhaust muffler 48 ... Belt type continuously variable transmission 49 ... Gear mechanism 57 ... Drive pulley 58 ... Driven pulley 59 ... Belt 60 ... Pulley shaft 63 ... For gear ratio control Electric motor 70 ... output shafts 80, 81 ... cooling fins 82 ... shroud 89 ... running wind intake opening 90 ... suction duct E ... internal combustion engine F ... body frame P ... Power unit WF ... Front wheel WR ... Rear wheel

Claims (7)

  A power unit (P) comprising an internal combustion engine (E) and an air-cooled belt-type continuously variable transmission (48) in which an endless belt (59) is wound around a drive pulley (57) and a driven pulley (58). ) Is mounted on the vehicle body frame (F) while being disposed between the front wheel (WF) and the rear wheel (WR), and the internal combustion engine (E) moves the axis of the crankshaft (27) along the longitudinal direction of the vehicle. In a saddle-ride type vehicle supported by a vehicle body frame (F), the drive pulley (57) is provided at a front end portion of the crankshaft (27) in the vehicle longitudinal direction, and the pulley shaft is provided with the driven pulley (58). (60) is disposed on one side in the vehicle width direction of the crankshaft (27) while having an axis parallel to the crankshaft (27), and accommodates the belt type continuously variable transmission (48). A transmission case (21) is connected to the engine body (20) of the internal combustion engine (E), and a traveling wind intake opening (89) communicating with the transmission case (21) is traveled from the front in the vehicle longitudinal direction. A saddle-ride type vehicle characterized by being able to take in wind and opening in front of the vehicle in the front-rear direction.   The engine body (20) is mounted on the body frame (F) in a posture in which a cylinder portion (26) constituting a part thereof is inclined toward the driven pulley (58) in the vehicle width direction, and the cylinder portion The saddle-ride type vehicle according to claim 1, wherein an air cleaner (39) disposed above (26) and an intake pipe (42) connected to the cylinder portion (26) are connected in the vertical direction. .   Cooling fins (80, 81) are provided on the outer surface of the cylinder part (26), and the inside of the shroud (82) covering the cylinder part (26) communicates with the transmission case (21). The saddle riding type vehicle according to claim 1 or 2.   The drive pulley (57) of the belt (59) is disposed at a front portion of the transmission case (21) along the vehicle front-rear direction at a portion located on the opposite side of the crankshaft (27) from the pulley shaft (60). The saddle-ride type vehicle according to any one of claims 1 to 3, further comprising a gear ratio control electric motor (63) capable of changing a winding diameter around.   The lower end part of the suction duct (90) having the opening part (89) for running wind intake at the upper end part and extending in the vertical direction is connected to the transmission case (21). 5. A saddle-ride type vehicle according to any one of 4 above.   The power unit (P) includes an output shaft (70) having an axis parallel to the pulley shaft (60), and a gear mechanism (49) interposed between the pulley shaft (60) and the output shaft (70). The front end of a drive shaft (19) extending in the vehicle front-rear direction so as to transmit power to the rear wheel (WR) side is connected to the output shaft (70). The saddle riding type vehicle according to any one of?   An exhaust pipe (44) connected to one side wall of the cylinder part (26) in the vehicle width direction is piped so as to extend in the vehicle width direction behind the cylinder part (26) in the vehicle width direction. The straddle-type vehicle according to any one of claims 1 to 6, wherein the saddle-ride type vehicle is connected to an exhaust muffler (45) disposed on the other side in the vehicle width direction of WR.