JP2009079691A - Power unit - Google Patents

Abstract

A power unit having a pulley groove width adjusting mechanism for adjusting a groove width of a pulley in a V belt type continuously variable transmission that transmits engine driving force from a driving pulley to a driven pulley via a V belt. In order to reduce the weight of a continuously variable transmission and to reduce noise, a power unit including technical means instead of a conventionally used centrifugal clutch is provided.
A drive pulley groove width is set large during idle operation so that the driving force of the engine is not transmitted to the driven pulley, and a driving pulley groove width is set small at the start of traveling to reduce the drive force applied to the driven pulley. A power unit including a V-belt type continuously variable transmission that performs transmission.
[Selection] Figure 6

Description

  The present invention relates to a power unit including a V-belt type continuously variable transmission.

In a V-belt type continuously variable transmission, transmission of driving force to a rear wheel is generally performed via a centrifugal clutch. However, since the centrifugal clutch includes a clutch outer, a clutch weight, and the like as components, there is a problem that it is desired to reduce the weight because the weight increases. Further, when the clutch is engaged, noise is generated because the clutch shoe intermittently contacts the clutch outer, so there is a problem of reducing noise. (For example, refer to Patent Document 1.)
JP-A-2005-133929.

  The present invention seeks to provide a power unit having technical means instead of a centrifugal clutch in order to reduce the weight and noise of a V-belt type continuously variable transmission.

The present invention solves the above problems, and the invention according to claim 1
In a power unit having a pulley groove width adjusting mechanism for adjusting a groove width of a pulley in a V belt type continuously variable transmission that transmits engine driving force from a driving pulley to a driven pulley via a V belt,
The present invention relates to a power unit that switches between connection and disconnection of engine driving force to a rear axle by adjusting a groove width of a pulley of a V-belt type continuously variable transmission.

The invention described in claim 2
In a power unit including an electric motor for adjusting a groove width of a driving pulley in a V-belt continuously variable transmission that transmits engine driving force from a driving pulley to a driven pulley via a V-belt,
During idle operation, the groove width of the drive pulley is set large so that the driving force of the engine is not transmitted to the driven pulley.
The present invention relates to a power unit including a V-belt continuously variable transmission that starts transmission of driving force to a driven pulley by setting a groove width of a driving pulley to be small at the start of traveling.

The invention according to claim 3 is the power unit according to claim 1 or 2,
A reduction gear mechanism for decelerating and transmitting the driving force transmitted to the driven shaft supporting the driven pulley of the V-belt type continuously variable transmission to the rear wheels;
The driving force transmitted to the driven pulley is directly transmitted to the driven shaft.

In the invention of claim 1,
Since a centrifugal clutch is not required, the power unit can be reduced in weight and noise during clutch-in can be reduced.

In the invention of claim 2,
Since a centrifugal clutch is not required, the power unit can be reduced in weight and noise during clutch-in can be reduced.
Further, since the space for arranging the centrifugal clutch becomes unnecessary, the V-belt type continuously variable transmission can be reduced in size.
Furthermore, since the half clutch state can be finely controlled by the electric motor, the driving force of the engine can be transmitted smoothly.

In the invention of claim 3,
Since the driving force transmitted to the driven pulley is directly transmitted to the driven shaft by a spline or the like without passing through the centrifugal clutch, the structure around the driven shaft is simplified.

  FIG. 1 is a side view of a motorcycle 1 equipped with a power unit P according to an embodiment of the present invention, and FIG. 2 is an enlarged view of a rear portion of the motorcycle 1. In FIG. 1, the body frame Fr of the motorcycle 1 includes a head pipe 3 that rotatably supports a front fork 2, a main frame 4 that extends rearwardly downward from the head pipe 3, and one end that is intermediate between the main frame 4. A pair of left and right rear frames 5 that are connected to each other and extend rearward, a downward frame that extends downward from the head pipe 3 and bends backward, and is connected to the lower end of the main frame 4, and the lower end of the main frame 4 and the rear frame The middle frame 7 is connected to the intermediate portion 5. A front wheel WF is pivotally supported at the lower end of the front fork 2, a steering handle 8 is connected to the upper portion of the front fork 2, and a front fender 9 covering the upper portion of the front wheel is supported by the front fork 2. A fuel tank 10 is provided between the main frame 4 and the down frame 6.

  Referring also to FIG. 2, pivot plates 150 are fixed to both side surfaces of the rear frame 5 and the middle frame 7. The power unit P swings with the cylinder axis slightly raised forward via the suspension link 152 held on the pivot plate 150 via the pivot shaft 151, the engine hanger 39 integrated with the power unit P, and the support shaft 153. Suspended as possible. A rear cushion 154 is provided between the rear end bracket 40 of the power unit P and the rear frame 5. A rear wheel WR is attached to the rear axle 27 protruding rightward from the rear portion of the power unit P, and is driven by the power unit P. A storage box 156 for storing the helmet 155 and the like is provided above the power unit P, and a riding seat 157 is disposed above the storage box 156. An air cleaner 158 is provided on the upper right side of the power unit P, and is connected to the throttle body 23 connected to the inlet pipe 30 via a connecting pipe 160. In FIG. 1, a vehicle body cover 161 including a plurality of synthetic resin members is attached to the vehicle body frame Fr to cover the power unit P and other devices. A rear fender 162 is provided at the rear of the vehicle. A muffler 164 connected to the exhaust pipe 163 of the engine is provided on the right side of the vehicle.

  FIG. 3 is a top view of the power unit P suspended on the rear part of the motorcycle. Arrow F points to the front of the vehicle. Rear frames 5 and 5 are provided on the left and right sides of the vehicle, and are connected to each other via connecting frames 165 and 166. A rear wheel WR is provided along the center line CC of the vehicle. A transmission case 32B and a transmission case cover 34 are provided on the left side of the vehicle. The front part of the transmission case is a left crankcase 32A. The left crankcase 32A and the right crankcase 33 constitute a crankcase 17. An air cleaner 158 is provided on the right side of the vehicle, and is connected to the throttle body 23 via a connecting pipe 160. A starter motor 60 and a drive pulley control electric motor 28 are provided above the crankcase 17. The starter motor 60 is attached to the right crankcase 33, and the drive pulley control electric motor 28 is attached to the left crankcase 32A. A muffler 164 is provided below the right side of the air cleaner 158.

  FIG. 4 is a side view of the power unit P. As shown in FIG. It is drawn with a part of the internal structure visible. An engine 11 is formed in the front part of the power unit P. A V-belt type continuously variable transmission comprising a drive pulley 12, a driven pulley 13 and an endless V-belt 14 wound around these from the engine 11 to the rear. A machine 15 is provided, and a power system reduction gear mechanism 16 is provided at the rear thereof.

  The engine 11 is a four-stroke cycle engine. In the front part of the power unit P, the cylinder block 18, the cylinder head 19, and the cylinder head cover 20 are stacked in order from the front end surface of the crankcase 17 to the front, until the state is almost horizontal. The posture is greatly inclined forward. A fuel injection valve 22 is attached to an inlet pipe 30 attached to the intake port 21 on the upper side of the cylinder head 19, and a throttle body 23 and an air cleaner 158 (FIGS. 1 to 3) are further connected to the rear. From the lower exhaust port 24 of the cylinder head 19, an exhaust pipe 163 (FIGS. 1 and 2) extends downward, bends backward, and is connected to the muffler 164 (FIGS. 1 and 3). An oil filter 31 is provided below the crankcase 17.

  In the V-belt continuously variable transmission 15, the drive shaft of the drive pulley 12 is a crankshaft 25. The rotation shaft of the driven pulley 13, that is, the driven shaft 26 is an input shaft of the power system reduction gear mechanism 16. The output shaft of the power system reduction gear mechanism 16 is a rear axle 27 to which a rear wheel WR (FIG. 1) is attached. A drive pulley control electric motor 28 and a drive pulley control unit reduction gear mechanism 29 are disposed above the crankshaft 25.

  5 is a cross-sectional view taken along the line AA in FIG. In the power unit P, the shells supporting the plurality of rotation shafts provided in the left and right directions are the left crankcase 32A, the transmission case 32B integrally connected to the rear of the left crankcase 32A, the right crankcase 33, the transmission case cover 34, It comprises a control unit gear cover 35 (FIG. 6) and a rear gear cover 36. The transmission case 32B and the transmission case cover 34 have long front and rear lengths. The control unit gear cover 35 is connected to the upper part of the transmission case cover 34. A front side cover 71 and a rear side cover 72 are provided on the left side of the transmission case cover 34, and a cooling air suction port 73 is formed between the two covers.

  The left crankcase 32A and the right crankcase 33 constitute a crankcase 17, and the transmission case 32B, the transmission case cover 34, the control unit gear cover 35 (FIG. 6), and the rear gear cover 36 constitute a transmission case 37. . The portion of the transmission case 37 sandwiched between the transmission case 32B and the transmission case cover 34 is divided into a transmission chamber 38 for housing the V-belt type continuously variable transmission 15, the left crankcase 32A and the control unit gear cover 35. The sandwiched portion is a housing portion of the drive pulley control unit reduction gear mechanism 29 (FIG. 6), and the portion sandwiched between the transmission case 32B and the rear gear cover 36 is a housing portion of the power system reduction gear mechanism 16. A cylinder block 18, a cylinder head 19, and a cylinder head cover 20 are stacked in order from the front end of the crankcase 17 in the forward direction.

  5, the crankshaft 25 is rotatably supported via journal bearings 42A and 42B of the left crankcase 32A and the right crankcase 33, and the left end of the crankshaft 25 is further connected to the transmission case cover 34 via a ball bearing 43. And is rotatably supported. A piston 45 is slidably fitted in a cylinder hole 44 formed in the cylinder block 18. Both ends of the connecting rod 46 are pivotally supported by the crankshaft 25 and the piston 45 via the crankpin 47 and the piston pin 48, respectively. When the piston 45 reciprocates, the crankshaft 25 rotates accordingly. A combustion chamber 49 is formed on the bottom surface of the cylinder head 19 facing the upper end surface of the piston 45, and a spark plug 50 is mounted from the side of the cylinder head 19, and the tip thereof faces the combustion chamber 49.

  A camshaft 51 is supported between the cylinder head 19 and the cylinder head cover 20 in parallel with the crankshaft 25, and the intake valves and exhaust valves are opened and closed by cams 51a and 51b provided on the camshaft 51. The camshaft 51 is rotationally driven by the crankshaft 25 by a cam chain 54 wound between a drive sprocket 52 provided at the right portion of the crankshaft 25 and a driven sprocket 53 provided at the right end of the camshaft 51. The

  A right crankcase cover 55 is provided on the right outer side of the right crankcase 33, and a stator 56 fixed to the inner surface of the right crankcase cover 55 and a rotor 57 fixed to the crankshaft 25 and surrounding the stator 56, A generator 58 is configured. A starter driven gear 59 is provided adjacent to the generator 58. This is a gear for the crankshaft 25 to receive rotational driving from the starter motor 60 (FIGS. 3 and 4).

  A balancer drive gear 62 is provided adjacent to the right crank web 61B of FIG. This is for driving the balancer 63 (FIG. 6) that rotates above the space between the left and right crank webs 61A, 61B.

  In FIG. 5, the transmission chamber 38 that houses the V-belt type continuously variable transmission 15 is provided between the transmission case 32 </ b> B and the transmission case cover 34. The drive shaft of the V-belt type continuously variable transmission 15 is the crankshaft 25 itself, and the left end portion of the crankshaft 25 protrudes from the left crankcase 32A into the left transmission chamber 38, and this projecting portion has a V-belt type. A drive pulley 12 for the continuously variable transmission 15 is provided. The drive pulley 12 includes a drive pulley fixed half 66 and a drive pulley movable half 67.

  The driven shaft 26 of the V-belt type continuously variable transmission 15 is rotatably supported by the transmission case cover 34, the transmission case 32B, and the rear gear cover 36 via ball bearings 70A, 70B, and 70C, respectively. The driven pulley 13 of the V-belt type continuously variable transmission 15 is attached to the driven shaft 26 so as to rotate integrally. The driven pulley 13 includes a driven pulley fixed half 74 and a driven pulley movable half 75.

  When the endless V-belt 14 is laid over the drive pulley 12 and the driven pulley 13 and the drive pulley 12 rotates, the rotation is transmitted to the driven pulley 13 and the driven shaft 26 that rotates integrally with the driven pulley 13 immediately rotates. start. The rotational torque of the driven shaft 26 is decelerated via the power system reduction gear mechanism 16, transmitted to the rear axle 27, and provided for the rotation of the rear wheel WR that is integrally fixed to the rear axle 27.

  The driving pulley 12 has a large groove width, that is, a gap between the opposing pulleys, when the engine is stopped and idling, so that a gap G is formed between the V belt 14 and the driving pulley 12. That is, the engine driving force is not transmitted to the V-belt 14 when the engine is stopped and idling. At the start of traveling, the driving force is transmitted to the V-belt 14 by reducing the groove width of the driving pulley 12.

  6 is a cross-sectional view taken along the line BB in FIG. A balancer 63 supported by ball bearings 65, 65 is provided above the space between the left and right crank webs 61A, 61B. The balancer 63 is rotationally driven through a balancer drive gear 62 provided on the crankshaft 25 adjacent to the right crank web 61B and a balancer driven gear 64 fixed to the balancer shaft.

  The drive pulley 12 provided on the crankshaft 25 protruding into the transmission chamber 38 is composed of a drive pulley fixed half 66 and a drive pulley movable half 67. A projecting portion of the crankshaft 25 into the transmission chamber 38 includes a first small-diameter portion 25A divided by a step 25a and a step 25b, a step 25b, and a shaft end 25c from the side near the center of the crankshaft 25. A partitioned second small diameter portion 25B is formed. Splines are provided on the shaft end side half of the first small diameter portion 25A and the shaft end side half of the second small diameter portion 25B, respectively. In order to prevent erroneous assembly, the first small diameter portion 25A has a larger diameter than the second small diameter portion 25B.

  An inner ring of a ball bearing 76, a first support sleeve 77, and a guide sleeve 78 are fitted into the first small diameter portion 25A, and a second support sleeve 79 and a driving pulley fixing half are inserted into the second small diameter portion 25B. 66 and collar 80 are fitted. The sleeves 77, 78, 79 and the collar 80 are made of steel, and the drive pulley fixing half 66 is an aluminum alloy member in which a hub portion 66A and an umbrella-like portion 66B are integrated. Each of the above members is fastened with a bolt 82 screwed into a screw hole at an end of the crankshaft 25 via a washer 81, and is fixed so as not to move in the direction of the crankshaft 25. Of the above members, the guide sleeve 78 is fitted into the spline of the first small diameter portion 25A of the crankshaft 25 via a spline formed on the inner surface thereof. The driving pulley fixing half 66 is fitted to the spline of the second small diameter portion 25B via a spline inside the center hole of the hub portion 66A. Therefore, the guide sleeve 78 and the driving pulley fixing half 66 are fixed so as not to rotate relative to the crankshaft 25 and rotate together with the crankshaft 25. The left end of the crankshaft 25 is supported by the transmission case cover 34 via the collar 80 and the ball bearing 43. The collar 80 is provided with grease grooves 80a for preventing fretting wear, and O-rings 80b are mounted in O-ring grooves provided on both sides thereof.

  The driving pulley movable half 67 includes a central steel movable half hub 67A and an aluminum alloy umbrella 67B. In this case, an umbrella-shaped portion 67B is integrally formed by casting at an end portion of a movable half-body hub portion 67A manufactured in advance.

  A projecting spline 67i projecting inward is formed on the inner periphery of the driving pulley movable half-body hub portion 67A, and is fitted to an outer periphery spline 78e formed on the outer periphery of the guide sleeve 78. Since the outer peripheral spline 78e of the guide sleeve 78 is a long spline in the axial direction, the protruding spline 67i is slidable in the axial direction in the groove of the outer peripheral spline 78e. Therefore, the drive pulley movable half 67 cannot be rotated relative to the crankshaft 25 but is held so as to be movable in the axial direction. Grease is applied to the groove of the outer peripheral spline 78e of the guide sleeve 78 to smooth the sliding of the protruding spline 67i of the movable half-body hub portion 67A. Seals 83 are provided at both ends of the movable half-body hub portion 67A to prevent the leakage of the grease and the intrusion of dust.

  7 is an enlarged cross-sectional view taken along the line VII-VII in FIG. The outer peripheral spline 25e of the crankshaft 25 and the inner peripheral spline 78i of the guide sleeve 78 mesh with each other. The outer peripheral spline 78e of the guide sleeve 78 and the projecting spline 67i of the movable half-body hub portion 67A are also engaged with each other. A gap 84 is provided between the outer peripheral surface of the guide sleeve 78 and the inner peripheral surface of the movable half body hub portion 67A in order to enable movement of air and grease accompanying the movement of the protruding spline 67i. The drive pulley movable half 67 receives torque from the crankshaft 25 and rotates together with the crankshaft 25 by the splines 25e, 78i, 78e, 67i.

  In FIG. 6, an inner ring of a ball bearing 76 is mounted on the crankshaft 25 so as not to move in the axial direction. The ball bearing outer ring holding member 85 holds the outer ring of the ball bearing 76 so that the ball bearing outer ring holding member 85 itself cannot move in the axial direction. A female thread cylindrical member 86 is integrated with a bolt 87 on the outer peripheral flange portion of the ball bearing outer ring holding member 85. A large-diameter gear 88 is formed on the outer periphery of the flange portion of the female screw cylindrical member 86. The ball bearing outer ring holding member 85, the female screw cylindrical member 86, the bolt 87, and the large-diameter gear 88 are integrated to form a fixed position rotating screw member 89. The fixed position rotation screw member 89 is a fixed position in the axial direction of the crankshaft 25 and can rotate independently of the crankshaft 25. The large-diameter gear 88 of the fixed-position rotating screw member 89 is rotationally driven by the driving pulley control electric motor 28 and the driving pulley control unit reduction gear mechanism 29.

  An inner ring of a ball bearing 91 is mounted on the outer periphery of the movable half-body hub portion 67A of the drive pulley 12 so as not to be relatively movable in the axial direction, and a male screw cylindrical member 92 integrally holds the outer ring of the ball bearing 91. . A male screw portion on the outer periphery of the male screw cylindrical member 92 is engaged with a female screw portion on the inner periphery of the female screw cylindrical member 86.

  An annular member 93 is fixed to the flange portion 92 a of the male screw cylindrical member 92 via a bolt 94. A part of the circumference of the annular member 93 extends rearward, and a rearward extension portion 93a extends to the right around the outer side of the large-diameter gear 88 of the fixed-position rotating screw member 89 at the outer end portion. 93b. The male screw cylindrical member 92 and the annular member 93 are integrated by a bolt 94 to form an axially moving screw member 95. The anti-rotation portion 93b is sandwiched between a pair of guide pieces 96, 96 (see also FIG. 8) that protrude from the inner surface of the transmission case 32B into the transmission chamber 38, and the rotation is restricted and the direction of the crankshaft 25 Guided to move. As a result, when the fixed-position rotating screw member 89 rotates, the axially moving screw member 95 connected to the anti-rotation portion 93b is guided to move in the crankshaft direction in a state where the rotation is restricted, and the crankshaft 25 Move in the axial direction. The fixed position rotating screw member 89 and the axially moving screw member 95 constitute a screw type feed mechanism for driving the driving pulley movable half.

  The annular member 93 is integrally formed with a left stopper 93c near the base of the rearward extension 93a. This is for detecting the limit of the rightward movement of the axially moving screw member 95. A right stopper 97 is attached by a bolt 98 to the tip of the rotation preventing portion 93b extending from the annular member 93. This is for detecting the limit of the leftward movement of the axially moving screw member 95.

  The fixed position rotation screw member 89 is rotationally driven by the drive pulley control electric motor 28 and the drive pulley control unit reduction gear mechanism 29. The rotation of the electric motor 28 is automatically controlled according to the vehicle speed, throttle opening, and engine speed. A control unit gear cover 35 is attached to the left side of the left crankcase 32A, and a control unit gear chamber 101 is formed in a portion sandwiched between the case 32 and the cover 35. The electric motor 28 is attached to the right outer surface of the left crankcase 32A via the attachment plate 102, and the motor case 103 covers the electric motor 28. A pinion 105 engraved on the rotating shaft 104 of the electric motor 28 enters the control unit gear chamber 101. Since the electric motor 28 is mounted outside the left crankcase 32A, maintenance of the electric motor 28 is ensured.

  A first intermediate gear 108 in which a large-diameter gear 106 meshing with the pinion 105 and a small-diameter gear 107 adjacent to the pinion 105 are integrally formed is connected to the left crankcase 32A and the control unit gear cover 35 via ball bearings 109 and 109. It is rotatably supported. A second intermediate gear 113 in which a large-diameter gear 110 that meshes with the small-diameter gear 107 and a small-diameter gear 111 that is integrally adjacent to the large-diameter gear 107 are inserted into and integrated with the rotary shaft 112 is controlled with the left crankcase 32A. The part gear cover 35 is rotatably supported via ball bearings 114 and 114. The small-diameter gear 111 meshes with the large-diameter gear 88 of the fixed-position rotating screw member 89 described above. FIG. 4 shows the rotation center 105 c of the pinion 105, the rotation center 108 c of the first intermediate gear 108, and the rotation center 113 c of the second intermediate gear 113.

  A worm 115 is formed at the left end of the rotation shaft 112 of the second intermediate gear 113 so as to mesh with a worm wheel at the tip of a movable half body position sensor (not shown). The position sensor mounting portion 116 is provided in the vicinity of the worm 115 of the control unit gear cover 35. The movable half body position sensor is a device that detects the amount of rotation of the second intermediate gear 113 by the meshing of the worm gear, and detects the movement position of the drive pulley movable half body 67 based on this.

  FIG. 8 is a side view of the drive pulley movable half body drive mechanism. The driving pulley movable half body driving mechanism is a mechanism including an electric motor 28, a control unit reduction gear mechanism 29, a fixed position rotating screw member 89, and an axially moving screw member 95. In the figure, in addition to the electric motor 28 and the control unit reduction gear mechanism 29, a large-diameter gear 88 as a constituent member of the fixed position rotating screw member 89, a male screw cylindrical member 92 as a constituent member of the axially moving screw member 95, A flange portion 92a and a rear extension portion 93a of the annular member 93 are shown. An annular portion of the annular member 93 is attached to the other side of the flange portion 92a of the male threaded cylindrical member 92, but since it overlaps, it cannot be directly seen in the figure.

  The outer peripheral portion of the flange portion 92a of the male screw cylindrical member 92 and the outer peripheral portion of the annular member 93 are in a position where they interfere with the large-diameter gear 110 of the second intermediate gear 113 when the normal circular outer peripheral shape is maintained. . Since the rearward extending portion 93a of the annular member 93 functions as a detent for the male screw cylindrical member 92, the outer peripheral portion of the flange portion 92a and the outer peripheral portion of the annular member 93 do not rotate. Accordingly, the portions of the outer peripheral portion of the flange portion 92a and the outer peripheral portion of the annular member 93 that interfere with the large-diameter gear 110 of the second intermediate gear 113 are not cut off because no particular functional inconvenience occurs. It is possible.

  FIG. 8 shows the flange portion 92a of the male screw cylindrical member 92 in which the notch 92x is formed along the tooth tip of the large diameter gear 110 of the second intermediate gear 113 as described above. A notch 93x is also provided on the outer periphery of the annular member 93 that overlaps the opposite side of the flange portion 92a of the male screw cylindrical member 92 and is not directly visible in the drawing. As a result, the distance between the crankshaft 25 and the rotating shaft 112 of the second intermediate gear 113 can be shortened, and the large-diameter gear 88 of the fixed-position rotating screw member 89 can be downsized. The body drive mechanism can be downsized and the power unit P can be downsized.

  FIG. 9 is a perspective view of the male threaded cylindrical member 92 assembled to the drive pulley movable half 67. The male screw portion 92b of the male screw cylindrical member 92 is visible. FIG. 10 is a perspective view of the annular member 93. The rear extension part 93a and the rotation stopper part 93b are visible. In these drawings, the notch 92x of the male screw cylindrical member 92 and the notch 93x of the annular member 93 are visible. By these notches, the drive pulley movable half body drive mechanism can be reduced in size.

  In FIG. 10, a rear extension portion 93 a and a rotation stop portion 93 b protrude from a part of the outer periphery of the annular member 93. A left stopper 93c for detecting the limit of the rightward movement of the axially moving screw member 95 is integrally formed near the base of the rearward extending portion 93a. Resin shoes 99 are attached to both side portions of the rotation preventing portion 93b. By the resin shoe 99, the axial direction slide of the rotation preventing portion 93b becomes smooth, whereby the axial movement of the axial movement screw member 95 can be made smooth. Further, it is possible to suppress noise generated between the rotation preventing portion 93b and a pair of guide pieces 96 and 96 (FIG. 8) formed in the transmission chamber 38 from the inner surface of the transmission case 32B. The screw hole 93d of the right stopper 97 (FIG. 6) mounting bolt can be seen at the tip of the rotation preventing portion 93b.

  The groove width of the drive pulley 12 in FIG. 6 indicates the groove width when the engine is stopped or idling. The groove width is the distance between the fixed half 66 and the movable half 67. In this state, the V-belt 14 is between the inner surface of the fixed half 66 of the drive pulley 12, the inner surface of the umbrella-shaped portion 67B of the movable half 67, and the outer peripheral surface of the hub portion 67A of the movable half 67. There is a slight gap G, and the V belt 14 is not gripped by the drive pulley 12. During engine idling, the crankshaft 25 and the drive pulley 12 rotate, but the V-belt 14 remains stationary. That is, the driving force of the engine is not transmitted to the V belt 14 and the driven pulley 13. Therefore, the driving force of the engine is not transmitted to the driven shaft 26 and the rear axle 27. This brings about the same result as the clutch OFF in the continuously variable transmission with the conventional centrifugal clutch.

  In FIG. 6, after the engine is started, when the electric motor 28 in a stopped state starts to rotate in the positive direction according to the control command, it passes through the pinion 105, the first intermediate gear 108, and the second intermediate gear 113. Power is transmitted, the fixed-position rotating screw member 89 rotates, and the screw portion of the axially moving screw member 95 that meshes with the screw portion of the fixed-position rotating screw member 89 is separated from the screw portion of the fixed-position rotating screw member 89. The axial movement screw member 95 moves in the axial direction of the crankshaft 25 because it receives thrust in the crankshaft direction. The thrust received by the axially moving screw member 95 is transmitted to the driving pulley movable half hub portion 67A via the ball bearing 91, and the driving pulley movable half 67 moves in the axial direction of the crankshaft 25, thereby driving the groove of the driving pulley. The width narrows. When the umbrella-like portions 66B and 67B of both halves 66 and 67 of the drive pulley come into contact with the V-belt 14, gripping of the V-belt 14 by the drive pulley 12 starts. When the groove width of the driving pulley 12 is gradually narrowed, the driving pulley 12 starts to grip the V-belt 14, but the driving pulley 12 rotates while sliding with respect to the V-belt 14 because the gripping force is weak. The driving force of the engine is transmitted to the V-belt 14 gradually in a half-clutch state by adjusting the groove width of the driving pulley. When the electric motor 28 is further rotated, the groove width of the drive pulley 12 is further narrowed, and the drive pulley 12 firmly holds the V-belt 14 so that the clutch is completely connected and the driving force of the engine is completely It is transmitted to the V belt 14. As the electric motor 28 rotates, the V-belt 14 moves in the outer peripheral direction of the drive pulley 12 and functions as a continuously variable transmission in which the gear ratio changes.

  When the electric motor 28 rotates in the reverse direction in response to the control command, the interval between the drive pulley fixed half 66 and the drive pulley movable half 67 is widened by the reverse process, and the V-belt 14 moves in the center direction. To do. When the engine speed becomes a predetermined value or less, the electric motor 28 is rotated until the gap G is generated between the V belt 14 and the drive pulley 12, and the engine driving force is applied to the rear axle. Cut the transmission path. That is, without using a centrifugal clutch, the electric motor 28 can finely control the groove width of the drive pulley 12 to smoothly transmit the engine driving force to the rear axle, thus reducing noise and vibration smoothly and automatically. The two-wheeled vehicle can be started.

  FIG. 11 is an enlarged cross-sectional view of the driven pulley 13 and the power system reduction gear mechanism 16 and its peripheral portion. The driven pulley 13 corresponding to the drive pulley 12 of the V-belt type continuously variable transmission 15 includes a driven pulley fixed half body 74 and a driven pulley movable half body 75 that are opposed to each other and supported by the driven shaft 26. Yes. The driven pulley fixed half 74 and the driven pulley movable half 75 are made of rivets 74C and 75C with aluminum alloy umbrella-shaped portions 74B and 75B at the ends of a steel fixed half hub 74A and a movable half hub 75A, respectively. It is attached and integrated with.

  The driven shaft 26 is rotatably supported by the transmission case cover 34, the transmission case 32B, and the rear gear cover 36 via ball bearings 70A, 70B, and 70C, respectively. A small-diameter portion 26A is formed on the left side portion of the driven shaft 26, and a fixed half-body hub portion 74A and a collar 122 are fitted to the small-diameter portion 26A in this order, and a nut 123 is screwed to the end portion so as to be integrated. It is concluded to. Since the fixed half-hub portion 74A is fitted to the driven shaft 26 via the spline 124, the fixed half-hub portion 74A rotates integrally with the driven shaft 26. The ball bearing 70 </ b> A is interposed between the transmission case cover 34 and the collar 122.

  On the outer periphery of the fixed half-hub portion 74A, a movable half-hub portion 75A that supports the driven pulley movable half 75 is provided slidably in the axial direction. A guide hole 75a is formed in the movable half hub portion 75A in the axial direction, and a guide pin 128 protruding from the fixed half hub portion 74A is slidably engaged with the guide hole 75a. Accordingly, the movable half hub portion 75A is regulated in relative rotation with the fixed half hub portion 74A by the guide pins 128, and is guided by the guide pins 128 and the guide holes 75a so as to pivot on the fixed half hub portion 74A. Can slide in the direction. A coil spring 129 is interposed between a support plate 126 attached to the left end of the fixed half-hub portion 74A and fixed by a nut 127 and the movable half-hub portion 75A. 75A is urged to the right, that is, in a direction in which the movable half umbrella-shaped portion 75B approaches the fixed half umbrella-shaped portion 74B.

  Since the driven pulley 13 is configured as described above, the movable half umbrella-shaped portion 75B rotates together with the fixed half-umbrella-shaped portion 74B and is slidable in the axial direction so as to be coil spring 129. Is biased in a direction approaching the fixed half umbrella-shaped portion 74B. The V-belt 14 is wound between the opposed umbrella-shaped portions 74B and 75B of the driven pulley fixed half 74 and the driven pulley movable half 75, and the driven pulley 13 according to the winding diameter on the drive pulley 12 side. The wrapping diameter of the belt changes and a continuously variable transmission is performed.

  When the driving pulley 12 rotates and the rotational driving force is transmitted to the driven pulley 13 via the V-belt 14, and the driven pulley 13 rotates, the rotational driving force of the driven pulley 13 is transmitted via the guide pin 128 and the spline 124. It is directly transmitted to the driven shaft 26 and input to the power system reduction gear mechanism 16.

  The power system reduction gear mechanism 16 from the driven shaft 26 to the rear axle 27 is constituted by a gear group provided on three rotating shafts. The first shaft is the right half of the driven shaft 26 of the V-belt type continuously variable transmission 15, and a small-diameter gear 130 is formed on the shaft 26. The second shaft is an intermediate shaft 132 rotatably supported by the transmission case 32B and the rear gear cover 36 via needle bearings 131, 131. The intermediate shaft 132 meshes with the small-diameter gear 130 of the driven shaft 26. A matching large-diameter gear 133 is integrally fitted, and a small-diameter gear 134 is engraved on the intermediate shaft 132 itself. The third shaft is a rear axle 27 that is rotatably supported by the transmission case 32B and the rear gear cover 36 via ball bearings 135, 135. The rear axle 27 includes a small-diameter gear 134 of the intermediate shaft 132. A large-diameter gear 136 that meshes with is fitted. With this configuration, the torque of the driven shaft 26 is decelerated via the power system reduction gear mechanism 16 and transmitted to the rear axle 27. A rear wheel WR (FIG. 1) is integrally fixed to the rear axle 27, and is rotated by a driving force generated by the engine and transmitted through the transmission.

As described above in detail, this embodiment provides the following effects.
(1) When the engine is stopped or idling, the groove width of the drive pulley 12 is so wide that the V belt 14 cannot be gripped. At this time, a gap G is generated between the V belt 14 and the drive pulley 12. Yes. During idling, the crankshaft 25 and the drive pulley 12 rotate, but the V-belt 14 remains stationary. When the electric motor 28 starts to rotate in the forward direction, the groove width of the driving pulley is narrowed, and the gripping of the V belt 14 by the driving pulley 12 starts. When the drive pulley 12 grips the V-belt 14, the rotation of the crankshaft 25 is transmitted to the driven pulley via the V-belt 14, and the rotation of the driven pulley starts. The rotation of the driven pulley 13 is directly transmitted to the driven shaft 26 via the guide pin 128 and the spline 124, and is input to the power system reduction gear mechanism 16, so that the rear wheel WR is rotationally driven. Therefore, since a centrifugal clutch is not required, the power unit can be reduced in weight, and noise at the time of clutch-in can be reduced.
(2) Since the conventional arrangement space for the centrifugal clutch is not required, the V-belt type continuously variable transmission can be reduced in size. Further, since the half clutch state can be finely controlled, the driving force of the engine can be transmitted smoothly.
(3) Since the driving force transmitted to the driven pulley is directly transmitted to the driven shaft by a spline or the like without passing through the centrifugal clutch, the structure around the driven shaft is simplified.

1 is a side view of a motorcycle 1 equipped with a power unit P according to an embodiment of the present invention. Fig. 2 is an enlarged view of a rear portion of the motorcycle 1. It is a top view of the power unit P suspended on the rear part of the motorcycle. It is a side view of the power unit P. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is a VII-VII cross-sectional enlarged view of FIG. It is a side view of a drive pulley movable half body drive mechanism. 7 is a perspective view of a male screw cylindrical member 92 assembled to a drive pulley movable half 67. FIG. 3 is a perspective view of an annular member 93. FIG. FIG. 3 is an enlarged cross-sectional view of a driven pulley 13 and a power system reduction gear mechanism 16 and the periphery thereof.

Explanation of symbols

  P: Power unit, 12: Drive pulley, 13: Driven pulley, 14 ... V belt, 15 ... V belt type continuously variable transmission, 28 ... Electric motor, 29 ... Control unit reduction gear mechanism, 32A ... Left crankcase, 32B ... Transmission case, 33 ... Right crankcase, 34 ... Transmission case cover, 35 ... Control unit gear cover, 37 ... Transmission case, 38 ... Transmission chamber, 66 ... Drive pulley fixed half, 67 ... Drive pulley movable half, 67A ... movable half-hub part, 67B ... umbrella-like part, 86 ... female screw cylindrical member, 88 ... large-diameter gear, 89 ... fixed position rotating screw member, 92 ... male screw cylindrical member, 95 ... axial moving screw member, 96 ... guide piece, 99 ... resin shoe, 124 ... spline, 128 ... guide pin.

Claims (3)

In a power unit having a pulley groove width adjusting mechanism for adjusting a groove width of a pulley in a V belt type continuously variable transmission that transmits engine driving force from a driving pulley to a driven pulley via a V belt,
A power unit that switches between connection and disconnection of engine driving force to the rear axle by adjusting a groove width of a pulley of a V-belt type continuously variable transmission. In a power unit including an electric motor for adjusting a groove width of a driving pulley in a V-belt continuously variable transmission that transmits engine driving force from a driving pulley to a driven pulley via a V-belt,
During idle operation, the groove width of the drive pulley is set large so that the driving force of the engine is not transmitted to the driven pulley.
A power unit comprising a V-belt type continuously variable transmission that starts transmission of driving force to a driven pulley by setting a groove width of the driving pulley to be small at the start of traveling. A reduction gear mechanism for decelerating and transmitting the driving force transmitted to the driven shaft supporting the driven pulley of the V-belt type continuously variable transmission to the rear wheels;
The power unit according to claim 1 or 2, wherein the driving force transmitted to the driven pulley is directly transmitted to the driven shaft.

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