JP4959480B2 - Power unit - Google Patents

Description

  The present invention relates to a power unit that includes a belt-type continuously variable transmission together with an internal combustion engine, and more particularly to a power unit that continuously shifts a belt-type continuously variable transmission using an electric motor for shifting.

There is a type of power unit that detects a shift state by including a pulley position sensor in a shift drive mechanism that shifts a belt type continuously variable transmission.
For example, Patent Document 1, Patent Document 2, and the like include an example provided with a pulley position sensor.

JP 2007-8405 A JP 2007-10103 A

In the present specification, the front, rear, left and right are determined based on the vehicle body with the forward direction of the vehicle on which the power unit is mounted as the front.
In the power units disclosed in Patent Document 1 and Patent Document 2, a single-cylinder four-cycle internal combustion engine is provided at the front part with the cylinder greatly tilted forward, and a belt type continuously variable transmission on the left side with respect to the body of the power unit. A machine is provided extending rearward.

In a belt type continuously variable transmission, a movable pulley half of a drive pulley supported by a crankshaft is moved in the axial direction by a speed change drive mechanism to change the winding diameter of the transmission belt and perform speed change. The mechanism is configured diagonally above the front of the drive pulley.
The speed change drive mechanism is a mechanism that moves the movable pulley half in the axial direction by decelerating the rotation of the speed change electric motor via a reduction gear or the like. From the position of the movable pulley half ahead of the speed change drive mechanism. A pulley position sensor for detecting a shift state is arranged.

The pulley position sensor is operated via a gear separately engaged with one speed reduction gear of the speed change drive mechanism, and is substantially the same as the speed reduction gear in the left-right direction as disclosed in Patent Document 2. It protrudes to the left of the part reduction gear.
Moreover, although the balancer is disclosed by patent document 1, the balancer exists in the same position as the cylinder of the left-right center position of an internal combustion engine.

Therefore, the pulley position sensor is not located between the reduction gear of the speed change drive mechanism on the left side of the cylinder in the left-right direction and the balancer at the left-right center position, and is located at the same position on the left and right to avoid mutual interference. It is located greatly forward.
Therefore, the crankcase bulges forward, the internal combustion engine becomes larger and the weight increases.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a power unit capable of reducing the size and weight of an internal combustion engine by arranging a pulley position sensor using a balancer layout space or the like. There is in point to offer.

In order to achieve the above object, an invention according to claim 1 is a power unit (20) pivotally supported on a front portion of a vehicle body so as to be swingable up and down, comprising a crank chamber (40C) of an internal combustion engine (30). ) Forming a crankcase (22, 23a) and a transmission case (23) extending rearward from either the left or right side of the crankcase (22, 23a) as a reference, and a unit case (21) And a balancer (76) that is rotatably supported by a crankcase (22, 23a) of the unit case (21) and absorbs vibration, and a transmission case (23) of the unit case (21). A belt-type continuously variable transmission (50) for shifting the driving force of the internal combustion engine (30) and transmitting it to the drive wheels (19), and a drive of the speed change electric motor (61) for reducing gears (63a, 63b, 65a , 65b) and the movable pulley half (51d) of the drive pulley (51) around which the transmission belt (58) of the belt type continuously variable transmission (50) is wound. A pulley position sensor for detecting a moving position of the movable pulley half (51d) by the speed change drive mechanism (60) in a power unit having a speed change drive mechanism (60) that moves and changes a winding diameter (75) is arranged between the reduction gears (63a, 63b, 65a, 65b) and the balancer (76) in the left-right direction, and the pulley position sensor (75) The power unit overlapped with the motor (61) .

The invention according to claim 2 is a power unit (20) pivotally supported on the front part of the vehicle body so as to be swingable up and down, and a crankcase (22C) forming a crank chamber (40C) of the internal combustion engine (30). 23a) and a transmission case (23) extending rearward from one of the left and right sides of the crankcase (22, 23a) as a reference, and the unit case (21) A balancer (76) that is rotatably supported by a crankcase (22, 23a) and absorbs vibration, and is housed in a transmission case (23) of the unit case (21) to drive the internal combustion engine (30). The belt-type continuously variable transmission (50) that shifts the force and transmits it to the drive wheels (19) and the drive of the transmission electric motor (61) are decelerated via the reduction gears (63a, 63b, 65a, 65b). Moving the movable pulley half (51d) of the drive pulley (51) around which the transmission belt (58) of the belt type continuously variable transmission (50) is wound to change the winding diameter. In a power unit including a speed change drive mechanism (60), a pulley position sensor (75) for detecting a moving position of the movable pulley half (51d) by the speed change drive mechanism (60) is The balancer (76) is disposed between the gears (63a, 63b, 65a, 65b) and the balancer (76), and the balancer (76) is connected to the pulley position sensor (75) and the reduction gears (63a, 63b, 65a, 65b) and the a power unit, characterized in that overlapping with transmission electric motor (61).

The invention according to claim 3 is a power unit (20) pivotally supported on the front portion of the vehicle body so as to be swingable up and down, and a crankcase (22C) forming a crank chamber (40C) of the internal combustion engine (30). 23a) and a transmission case (23) extending rearward from one of the left and right sides of the crankcase (22, 23a) as a reference, and the unit case (21) A balancer (76) that is rotatably supported by a crankcase (22, 23a) and absorbs vibration, and is housed in a transmission case (23) of the unit case (21) to drive the internal combustion engine (30). The belt-type continuously variable transmission (50) that shifts the force and transmits it to the drive wheels (19) and the drive of the transmission electric motor (61) are decelerated via the reduction gears (63a, 63b, 65a, 65b). Moving the movable pulley half (51d) of the drive pulley (51) around which the transmission belt (58) of the belt type continuously variable transmission (50) is wound to change the winding diameter. In a power unit including a speed change drive mechanism (60), a pulley position sensor (75) for detecting a moving position of the movable pulley half (51d) by the speed change drive mechanism (60) is A drive shaft (61a) of the speed change electric motor (61) and the reduction gears (63a, 63b, 65a, 65b) are disposed between the gears (63a, 63b, 65a, 65b) and the balancer (76). ) Reduction gear shafts (63s, 65s) are power units arranged so as to lean on both sides of the rotational operation shaft (75a) of the pulley position sensor (75) in a side view.

  According to the power unit of the first aspect, since the pulley position sensor is disposed between the reduction gear of the speed change drive mechanism and the balancer in the left-right direction, the pulley position sensor is used as the reduction gear using the balancer layout space. Because it is not necessary to position the pulley position sensor back and forth or up and down while avoiding interference with the reduction gear and balancer, the internal combustion engine can be kept compact without causing the crankcase to bulge out. .

Since the pulley position sensor (75) overlaps with the speed change electric motor (61) in a side view, the pulley position sensor (75) and the speed change electric motor (61) are arranged in an intensive manner to The engine (30) can be made compact.

According to the power unit of claim 2 , the balancer (76) is configured to overlap the pulley position sensor (75), the reduction gears (63a, 63b, 65a, 65b), and the transmission electric motor (61) in a side view. Therefore, using the layout space of the balancer (76), the electric motor for shifting (61), the reduction gears (63a, 63b, 65a, 65b), and the pulley position sensor (75) can be arranged, making the internal combustion engine compact. Can be

According to the power unit of the third aspect, the drive shaft (61a) of the speed change electric motor (61) and the reduction gear shaft (63s, 65s) of the reduction gear (63a, 63b, 65a, 65b) are in the side view. Since the pulley position sensor (75) is arranged so as to be close to both sides of the rotation operating shaft (75a), the transmission electric motor (61), the reduction gear (63a, 63b, 65a, 65b) and the pulley position sensor (75) Can be arranged more collectively, and the internal combustion engine (30) can be made more compact.

Hereinafter, an embodiment according to the present invention will be described with reference to FIGS.
FIG. 1 is a side view of a motorcycle 1 according to an embodiment to which the present invention is applied.
The body frame of the motorcycle 1 is bifurcated from the upper part of the head pipe 2 at the front of the vehicle body to the back, and a pair of left and right main frames 3 extend obliquely downward. The frame 4 is bifurcated downward and extends, bends backward at the lower end and extends horizontally, and is connected to the rear end of the main frame 3.

Each of the seat rails 5 extends rearward and obliquely upward from a portion closer to the rear than the center of the pair of main frames 3, and the inclination gradually decreases to reach the rear end.
A middle frame 6 is interposed between the central portion of the seat rail 5 and the rear end of the main frame 3, and a rail stay 7 is interposed between the middle frame 6 and the rear end of the seat rail 5. Has been.

A front and rear long storage box 8 is installed between the pair of left and right seat rails 5 and 5 of the body frame as described above, and a front seat 9f and a rear seat 9r cover the storage box 8 in an openable and closable manner.
The front portion of the storage box 8 covered by the front seat 9f is a helmet box 8hf, and the rear portion covered by the rear seat 9r is another helmet box 8hr.

A handle 11 is provided above and supported by the head pipe 2 at the front of the vehicle body, and a front fork 12 extends downward and a front wheel 13 is supported at the lower end thereof.
A pivot plate 14 is installed at the corner where the seat rail 5 and the middle frame 6 are connected in the center of the vehicle body, and the power unit 20 swings through a suspension link 16 pivotally supported by the pivot shaft 15 of the pivot plate 14. It is connected and supported freely.

  The power unit 20 includes an internal combustion engine 30 at a front portion of a unit case 21, a belt-type continuously variable transmission 50 is disposed from the internal combustion engine 30 to the rear, and a reduction gear mechanism 110 is integrally provided at a rear portion thereof. The rear wheel 19 is attached to the output shaft 114 of the reduction gear mechanism 110 (see FIG. 1).

  Referring to FIGS. 1 and 2, the power unit 20 has a pair of left and right power unit hangers 21h and 21h projecting forward at the front upper portion of the front portion of the unit case 21, and a supporting shaft 17 at the lower end of the suspension link 16. The power unit hangers 21h and 21h are connected to each other, and on the other hand, a rear cushion 18 is provided between the rear end bracket 27 of the unit case 21 (transmission case 23) and the rear end of the seat rail 5 at the swingable rear portion. It is intervened.

  The internal combustion engine 30 is a single-cylinder four-cycle internal combustion engine, and protrudes from the front surface of the unit case 21 in a posture in which the cylinder block 31, the cylinder head 32, and the cylinder head cover 33 are superposed to a substantially horizontal state. Yes.

  A throttle body 35 is connected to an intake pipe 34 that extends upward from the upper intake port of the cylinder head 32 and bends backward, and a connecting pipe 36 that extends rearward from the throttle body 35 extends along the right side of the rear wheel 19. It is connected to the arranged air cleaner 37.

  The throttle body 35 is located in the vicinity of the support shaft 17 that pivotally supports the unit case 21. Therefore, the throttle body 35 is disposed in a place where the amplitude when the power unit 20 swings is relatively small. The throttle operation can be executed with high accuracy.

An exhaust pipe 38 extending downward from the lower exhaust port of the cylinder head 32 and bent rearward is biased to the right and extends rearward to be connected to the right muffler 39 of the rear wheel 19.
A fuel tank 10 is disposed between the pair of left and right main frames 3 and the down frame 4.
The vehicle body frame is entirely covered with a vehicle body cover C in which synthetic resin cover members divided into respective parts are connected.

  2 is a left side view of the power unit 20, FIG. 3 is a right side view of the front portion of the power unit 20, and FIG. 4 shows the power unit 20 generally along the lines IV-IV and IV′-IV in FIGS. It is sectional drawing cut | disconnected and expanded along line | wire.

The unit case 21 is divided into left and right parts, and the left unit case extends rearward with respect to the right unit case 22 to constitute a transmission case 23.
The transmission case 23 includes a left crankcase portion 23a formed on the front right side, a transmission case portion 23b formed on the left side from the front portion to the rear portion, and a reduction gear case portion 23c formed on the rear right side. The left crankcase portion 23a is combined with the right unit case 22 to form a crank chamber 40C that accommodates the crankshaft 40, and the transmission case portion 23b is covered with the transmission case cover 24 from the left side so as to be a belt type continuously variable transmission 50. Is formed, and the reduction gear case 23c at the rear is covered with the reduction gear cover 111 to form a reduction gear chamber in which the reduction gear mechanism 110 is accommodated (see FIG. 1).

  In the crank chamber 40C, the crankshaft 40 is rotatably supported by the left and right bearing circular holes of the unit case 21 via main bearings 41 and 41, and a pair of left and right crank webs 40w and 40w are accommodated in the left and right horizontal directions. An AC generator 42 is provided in the right extension portion of the extended portion, and a drive pulley 51 of the belt type continuously variable transmission 50 is provided in the left extension portion together with the speed change drive mechanism 60.

The drive pulley 51 includes a fixed pulley half 51s and a movable pulley half 51d.
The bearing 52, the guide sleeve 53, and the fixed pulley half 51s are fitted in this order from the right to the left extending portion from the step portion 40a that is reduced in diameter to the small diameter of the crankshaft 40, and a washer 55 is attached to the left end surface of the crankshaft 40. The inner ring of the bearing 52, the guide sleeve 53, and the base of the fixed pulley half 51 s are tightened to be integrated with the crankshaft 40.

  Accordingly, the fixed pulley half 51 s is sandwiched between the guide sleeve 53 and the washer 55 and fixed integrally with the crankshaft 40, and rotates together with the crankshaft 40.

  On the other hand, the movable pulley half 51d facing the fixed pulley half 51s on the right side is rotated simultaneously with the crankshaft 40 while the cylindrical movable pulley hub 51dh, which is the base thereof, is partially spline-fitted to the guide sleeve 53. It is slidable in the direction.

Thus, the right movable pulley half 51d facing the left fixed pulley half 51s rotates together with the crankshaft 40 and slides in the axial direction so as to approach and separate from the fixed pulley half 51s. The V belt 58 is sandwiched and wound between the tapered surfaces of the pulley halves 51s and 51d facing each other.
A driven pulley 81 corresponding to the drive pulley 51 is supported by a rear driven shaft 82, and a V-belt 58 is bridged between the drive pulley 51 and the driven pulley 81 (see FIG. 1).

  In the crank chamber 40C formed by the left crankcase portion 23a and the right crankcase 22, the balancer 76 is pivoted slightly through the bearings 77 and 77 at both ends of the balancer shaft 76s slightly rearward above the crankshaft 40. The balancer weight 76w is located between the pair of crank webs 40w, 40w and overlapped in a side view.

In the crank chamber 40C, a balancer driven gear 78b is fitted to the balancer shaft 76s adjacent to the right bearing 77, and the balancer driven gear 78b is fitted to the crankshaft 40 adjacent to the right crank web 40w. It meshes with the worn balancer drive gear 78a.
The balancer driving gear 78a and the balancer driven gear 78b have the same diameter.
Accordingly, the balancer 76 rotates in the reverse direction at the same speed as the crankshaft 40 and reduces the primary vibration of the internal combustion engine 30.

An AC generator 42 is provided at the right end of the crankshaft 40, and a right case cover 28 covers the AC generator 42 from the right side so as to cover the AC generator 42.
The front part of the transmission case 23 and the transmission case cover 24 constituting the transmission chamber 50C bulges above the drive pulley 51, and the speed change drive mechanism 60 is provided in the bulged parts 23e, 24e.

Referring to FIGS. 2 and 4, support substrate 25 is attached from the left side with a space to the side wall of bulging portion 23 e of transmission case 23.
The speed change electric motor 61 of the speed change drive mechanism 60 is attached to the support substrate 25 from the left side via the motor attachment 26.

  The speed change electric motor 61 protruding from the left side of the support substrate 25 by the motor fixture 26 passes through the side surface of the bulging portion 23e of the transmission case cover 24 and comes out to the outside. A seal member 29 is interposed between the opening and the outer peripheral surface of the speed change electric motor 61 (see FIG. 4).

As shown in FIG. 4, a first reduction gear shaft 63s is rotatably supported between the support substrate 25 and the side wall surface of the transmission case 23 via bearings 62, 62. A large-diameter gear 63a fitted to the left end of the 63s through the support substrate 25 meshes with a drive gear 61a formed on a drive shaft 61s protruding to the right of the transmission electric motor 61.
Similarly, a second reduction gear shaft 65s is rotatably supported between the support substrate 26 and the side wall of the transmission case 23 via bearings 64, 64, and is integrated with the second reduction gear shaft 65s. A diameter gear 65a meshes with a small diameter gear 63b integral with the reduction gear shaft 63s.

On the other hand, a female screw member 67 is fixed to a disc boss member 66 supported at the base end by an outer ring of a bearing 52 fitted to the crankshaft 40 with a bolt 68, and a large diameter is provided to a flange portion of the female screw member 67. A gear 67a is formed, and the large diameter gear 67a meshes with a small diameter gear 65b integral with the second reduction gear shaft 65s.
A female screw (screw screw) is formed on the inner peripheral surface of the cylindrical portion 67 s of the female screw member 67.

A male screw member 70 is supported via a bearing 69 that is supported on the outer periphery of a movable pulley hub 51dh that supports the movable pulley half 51d and is slidable in the axial direction. Inside the cylindrical portion 67s of the member 67, a male screw formed on the outer peripheral surface of the cylindrical portion 70s is screwed with a female screw on the inner peripheral surface of the cylindrical portion 67s.
In the male screw member 70, the left end of the cylindrical portion 70s is exposed to the left from the left opening end of the cylindrical portion 67s of the female screw member 67, and the flange portion 70a extends in the centrifugal direction along the back surface of the movable pulley half 51d from the left end. It extends to.

  An annular member 71 is fixed to the outer peripheral portion of the flange portion 70a of the male screw member 70, and the rear portion of the annular member 71 extends rearward and extends rightward in the axial direction so as to wrap around the outside of the large-diameter gear 67a of the female screw member 67. The pair of upper and lower guide pieces 72, 72 projecting into the transmission chamber 50C of the transmission case 23 regulates the rotation of the extension portion 71a and guides the movement in the axial direction. (See FIG. 4).

  Therefore, the male screw member 70 supported by the movable pulley hub 51dh integral with the movable pulley half 51d via the bearing 69 is restricted in rotation by the guide pieces 72, 72 and can slide only in the axial direction.

  The speed change drive mechanism 60 is configured as described above, and when the speed change electric motor 61 is driven and the drive gear 61a formed on the drive shaft 61s rotates, the first reduction gear shaft 63s meshes with the drive gear 61a. The large-diameter gear 63a rotates at a reduced speed together with the small-diameter gear 63b, and the large-diameter gear 65a of the second reduction gear shaft 65s that meshes with the small-diameter gear 63b further rotates at a reduced speed together with the small-diameter gear 65b. The large-diameter gear 67a of the member 67 further rotates at a reduced speed, and the female screw member 67 rotates.

When the female screw member 67 rotates, the male screw member 70 screwed with the female screw member 67 is restricted from rotating, so that it moves in the axial direction by the screw mechanism.
The male screw member 70 is moved in the axial direction by moving the movable pulley hub 51dh in the axial direction integrally with the movable pulley half 51d via the bearing 69, and moving the movable pulley half 51d toward and away from the fixed pulley half 51s. Can do.

  The movable pulley half 51d is moved in the axial direction while rotating together with the crankshaft 40 because the movable pulley hub 51dh that integrally supports the movable pulley half 51d is spline-fitted to the guide sleeve 53 integral with the crankshaft 40. become.

  In this way, the movable pulley half 51d approaches and separates from the fixed pulley half 51s by forward / reverse driving of the speed change electric motor 61, so that the pulleys 51s and 51d are wound between the opposing tapered surfaces. The winding diameter of the V-belt 58 is changed to perform continuously variable transmission.

  As shown in FIGS. 2 and 3, the speed change drive mechanism 60 has a first reduction gear shaft 63s (large diameter gear 63a, small diameter gear) obliquely below the drive shaft 61s (drive gear 61a) of the electric motor 61 for speed change. 63b) is located, the second reduction gear shaft 65s (large diameter gear 65a, small diameter gear 65b) is located below the first reduction gear shaft 63s, and the crankshaft is diagonally forward and downward from the second reduction gear shaft 65s. The arrangement structure is such that 40 (large-diameter gear 67a) is positioned.

The second reduction gear shaft 65 s has a worm gear 65 w formed at the right end portion that extends further to the right than the right bearing 64.
A sensor insertion tube portion 23s is formed on the upper wall on the right side of the bulging portion 23e in the transmission case 23 so as to be inclined obliquely in the vertical direction (slightly tilted forward), and rotates to the sensor insertion tube portion 23s. A pulley position sensor 75, which is a type potentiometer, is attached so as to insert the rotational operation shaft 75a from above (see FIG. 3).

  As shown by a two-dot chain line in FIG. 4, the position where the pulley position sensor 75 is arranged is between the balancer 76 and the speed change drive mechanism 60, and the pulley position sensor 75 is arranged using the layout space of the balancer 76. As shown, a sensor insertion cylinder portion 23s is formed in the left crankcase portion 23a.

  The rotation operating shaft 75a of the pulley position sensor 75 inserted into the sensor insertion cylinder portion 23s has a worm gear mechanism in which a worm wheel 75w fitted at the tip portion meshes with a worm gear 65w at the right end portion of the second reduction gear shaft 64. Is configured.

  Therefore, when the speed change electric motor 61 is driven to rotate the second reduction gear shaft 64 through the engagement of the reduction gear of the speed change drive mechanism 60, the rotation operating shaft 75a is rotated via the worm gear mechanism. A pulley position sensor 75 detects the amount of rotation.

The amount of rotation detected by the pulley position sensor 75 is the amount of movement of the movable pulley half 51d in the axial direction, that is, the amount of fluctuation of the winding diameter of the V belt 58 around the drive pulley 51.
Therefore, the pulley position sensor 75 detects the shift state of the belt type continuously variable transmission 50 from the axial position of the movable pulley half 51d.

  The rotational operation shaft 75a of the pulley position sensor 75 inserted obliquely into the sensor insertion cylinder 23s of the transmission case 23 is located on the right side of the speed change drive mechanism 60 and on the left side of the balancer 76 (balancer weight 76w) ( 4 and the side view shown in FIGS. 2 and 3, the rotation operating shaft 75a includes the transmission electric motor 61 of the transmission drive mechanism 60, the large-diameter gear 63a on the first reduction gear shaft 63s, and the small-diameter gear. 63b overlaps with the large diameter gear 65a and the small diameter gear 65b on the second reduction gear shaft 65s, and also overlaps with the balancer weight 76w of the balancer 76 (see FIGS. 2 and 3).

  2 and 3, the drive shaft 61s of the speed change electric motor 61 approaches the rotational operation shaft 75a of the pulley position sensor 75 from the front side, and below the first reduction gear shaft 63s from the rear side. The second reduction gear shaft 65s is approaching from the front side and further downward, and the worm gear 65w at the tip thereof is screwed to the worm wheel 75w fitted near the lower end of the rotation operation shaft 75a.

  That is, in side view, the speed change electric motor 61 of the speed change drive mechanism 60, the large diameter gear 63a, the small diameter gear 63b on the first reduction gear shaft 63s, the large diameter gear 65a and the small diameter gear 65b on the second reduction gear shaft 65s. However, they are gathered so as to be close to the rotational operation shaft 75a of the pulley position sensor 75.

In this power unit 20, a starter motor 120 is attached to the right crankcase 22 from the left side, slightly behind the power unit hanger 21h on the front side of the upper mating surface of the right crankcase 22 and the left crankcase portion 23a. (See FIGS. 2, 3, and 4).
The starter motor 120 is attached from the left side to the left side surface of the bulging portion 22e that bulges somewhat upward on the right side of the right crankcase 22 with the drive shaft 120s protruding rightward (see FIG. 3).
Note that a mounting bracket 120b formed to protrude from the left side surface of the starter motor 120 is screwed and fixed to a boss portion of the left crankcase portion 23a (see FIGS. 2 and 4).

  A reduction gear shaft 121 is provided between the right crankcase 22 and the right case cover 28 between the drive shaft 120s of the starter motor 120 and the crankshaft 40, and is freely rotatable on the reduction gear shaft 121s. The shaft-supported large-diameter gear 122a meshes with the drive gear 120a formed on the drive shaft 120s (see FIG. 4).

On the other hand, a driven gear 123 is fitted and supported on a rotating boss 124 rotatably supported on the crankshaft 40 adjacent to an AC generator 42 provided at the right end of the crankshaft 40 (see FIG. 4). A driven gear 123 meshes with a small diameter gear 122b that is integral with the large diameter gear 122a.
A one-way clutch 125 is interposed between the outer rotor 42r integral with the crankshaft 40 of the AC generator 42 and the rotating boss 124.

  Accordingly, when the starter motor 120 is driven and the drive gear 120a formed on the drive shaft 120s rotates, the large-diameter gear 122a that meshes with the drive gear 120a rotates at a reduced speed together with the small-diameter gear 122b, and the driven gear that meshes with the small-diameter gear 122b. The gear 123 further rotates at a reduced speed together with the rotating boss 124, and the rotation of the rotating boss 124 rotates the outer rotor 42r of the AC generator 42 together with the crankshaft 40 via the one-way clutch 125, so that the internal combustion engine 30 can be started. .

  As described above, in the power unit 20, the pulley position sensor 75 has the reduction gears (the first reduction large diameter gear 63a, the first reduction small diameter gear 63b, the second reduction large diameter gear 65a, Since the second reduction small-diameter gear 65b) and the balancer 76 (balancer weight 76w) are arranged, the pulley position sensor 75 is placed inside the reduction gears 63a, 63b, 65a, 65b using the layout space of the balancer 76. (Right side) (see Fig. 4), and it is not necessary to position the pulley position sensor 75 back and forth or vertically away from the reduction gears 63a, 63b, 65a, 65b and the balancer 76, so the crankcase The internal combustion engine 30 can be kept compact without causing the bulges 22 and 23a to be reduced in size and weight.

  In the case of this power unit 20, the balancer 76 overlaps with the pulley position sensor 75 and the reduction gears 63a, 63b, 65a, 65b and also with the speed change electric motor 61 in the side view shown in FIGS. By utilizing the layout space of the balancer 76, the transmission electric motor 61, the reduction gear, and the pulley position sensors 63a, 63b, 65a, 65b can be arranged, and the internal combustion engine 30 can be further downsized.

  2 and 3, the drive shaft 61s partially overlaps from the front side in order from the top to the bottom with respect to the rotational operation shaft 75a oriented in the diagonally up and down direction of the pulley position sensor 75, and the first reduction gear. The shafts 63s are partially arranged from the rear side, and the second reduction gear shafts 65s are arranged in a staggered manner with respect to the rotational operation shaft 75a so as to approach from the front side.

  In this way, the drive shaft 61s of the speed change electric motor 61 and the reduction gear shafts 63s, 65s of the reduction gears 63a, 63b, 65a, 65b are arranged so as to lean on both sides of the rotational operation shaft 75a of the pulley position sensor 75 in a side view. Therefore, the speed change electric motor 61, the reduction gears 63a, 63b, 65a, 65b, and the pulley position sensor 75 can be arranged more collectively, and the internal combustion engine can be made more compact to promote reduction in size and weight. Can do.

  Since the transmission electric motor 61 and the starter motor 120 are arranged above the front portion of the unit case 21, the transmission electric motor 61 and the starter motor 120 are reliably protected from water and mud to improve durability. In addition, the transmission electric motor 61 and the starter motor 120 can be attached from above the unit case 21, and the assembling work can be easily and reliably performed.

1 is an overall side view of a motorcycle according to an embodiment of the present invention. It is the left view which removed the transmission case cover of the front part of a power unit. It is a right view of the front part of a power unit. FIG. 4 is a cross-sectional view of the power unit cut and developed substantially along the lines IV-IV and IV′-IV ′ of FIGS. 2 and 3.

Explanation of symbols

20 ... Power unit, 21 ... Unit case, 22 ... Right unit case, 23 ... Transmission case, 23a ... Left crankcase part,
30 ... Internal combustion engine, 40 ... Crankshaft, 50 ... Belt-type continuously variable transmission, 51 ... Drive pulley, 51d ... Movable pulley half, 51s ... Fixed pulley half, 58 ... V belt,
60 ... transmission drive mechanism, 61 ... electric motor for transmission, 61s ... first reduction gear shaft, 61a ... first reduction large diameter gear, 61b ... first reduction small diameter gear, 65s ... second reduction gear shaft, 65a ... second Reduction large-diameter gear, 65b ... second reduction small-diameter gear, 67 ... female screw member, 70 ... male screw member,
75 ... pulley position sensor, 76 ... balancer, 76s ... balancer shaft, 76w ... balancer diet, 78b ... balancer driven gear, 120 ... starter motor.

Claims (3)

A power unit (20) that is pivotally supported by a front part of a vehicle body and is swingable up and down.
A crankcase (22, 23a) forming the crank chamber (40C) of the internal combustion engine (30) and a transmission case extending rearward from either the left or right side of the crankcase (22, 23a) as a reference A unit case (21) consisting of
A balancer (76) that is rotatably supported by the crankcase (22, 23a) of the unit case (21) and absorbs vibration;
A belt-type continuously variable transmission (50) housed in the transmission case (23) of the unit case (21) to shift the driving force of the internal combustion engine (30) and transmit it to the drive wheels (19);
A drive pulley on which the transmission belt (58) of the belt-type continuously variable transmission (50) is wound by decelerating the drive of the transmission electric motor (61) via the reduction gears (63a, 63b, 65a, 65b) In a power unit including a shift drive mechanism (60) that moves the movable pulley half (51d) of 51) to change the winding diameter and change the speed,
A pulley position sensor (75) for detecting the moving position of the movable pulley half (51d) by the speed change drive mechanism (60) is provided with the reduction gears (63a, 63b, 65a, 65b) and the balancer (76 )
The power unit, wherein the pulley position sensor (75) overlaps the electric motor (61) for shifting in a side view. A power unit (20) that is pivotally supported by a front part of a vehicle body and is swingable up and down.
A crankcase (22, 23a) forming the crank chamber (40C) of the internal combustion engine (30) and a transmission case extending rearward from either the left or right side of the crankcase (22, 23a) as a reference A unit case (21) consisting of
A balancer (76) that is rotatably supported by the crankcase (22, 23a) of the unit case (21) and absorbs vibration;
A belt-type continuously variable transmission (50) housed in the transmission case (23) of the unit case (21) to shift the driving force of the internal combustion engine (30) and transmit it to the drive wheels (19);
A drive pulley on which the transmission belt (58) of the belt-type continuously variable transmission (50) is wound by decelerating the drive of the transmission electric motor (61) via the reduction gears (63a, 63b, 65a, 65b) In a power unit including a shift drive mechanism (60) that moves the movable pulley half (51d) of 51) to change the winding diameter and change the speed,
A pulley position sensor (75) for detecting the moving position of the movable pulley half (51d) by the speed change drive mechanism (60) is provided with the reduction gears (63a, 63b, 65a, 65b) and the balancer (76 )
The power unit, wherein the balancer (76) overlaps the pulley position sensor (75), the reduction gears (63a, 63b, 65a, 65b), and the transmission electric motor (61) in a side view. A power unit (20) that is pivotally supported by a front part of a vehicle body and is swingable up and down.
A crankcase (22, 23a) forming the crank chamber (40C) of the internal combustion engine (30) and a transmission case extending rearward from either the left or right side of the crankcase (22, 23a) as a reference A unit case (21) consisting of
A balancer (76) that is rotatably supported by the crankcase (22, 23a) of the unit case (21) and absorbs vibration;
A belt-type continuously variable transmission (50) housed in the transmission case (23) of the unit case (21) to shift the driving force of the internal combustion engine (30) and transmit it to the drive wheels (19);
A drive pulley on which the transmission belt (58) of the belt-type continuously variable transmission (50) is wound by decelerating the drive of the transmission electric motor (61) via the reduction gears (63a, 63b, 65a, 65b) In a power unit including a shift drive mechanism (60) that moves the movable pulley half (51d) of 51) to change the winding diameter and change the speed,
A pulley position sensor (75) for detecting the moving position of the movable pulley half (51d) by the speed change drive mechanism (60) is provided with the reduction gears (63a, 63b, 65a, 65b) and the balancer (76 )
The drive shaft (61a) of the speed change electric motor (61) and the reduction gear shafts (63s, 65s) of the reduction gears (63a, 63b, 65a, 65b) rotate the pulley position sensor (75) in a side view. A power unit characterized by being arranged so as to be close to both sides of the operating shaft (75a).

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