JP2009190486A - Power unit for small vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the intrusion of dust into the meshing part of a drive gear and an idle gear in a speed reduction gear mechanism for shifting gears with a configuration to avoid increase in the number of components. <P>SOLUTION: In a power unit for a small vehicle in which the speed reduction gear mechanism for shifting gears stored in a transmission case, while including the drive gear fixed to a motor shaft of an electric motor for shifting gears and the idle gear engaging with the drive gear, is interposed between the electric motor for shifting gears mounted on an outer surface of the transmission case stored with a V-belt type continuously variable transmission, and a movable pulley half body composing a part of a drive pulley, and a gear case supporting the speed reduction gear mechanism for shifting gears is mounted on the case member together with a case member composing a part of the transmission case, a protrusion 56a surrounding the engaging part of the drive gear 106 and the idle gear 114 and abutting on the gear case 113 is integrally provided to the case member 56 of the transmission case 54 so as to project into the gear case 113 side. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a V-belt type in which an endless V-belt is wound around a drive pulley mounted on a rotating shaft that outputs rotational power of an engine and a driven pulley capable of transmitting rotational power to drive wheels. A continuously variable transmission is housed in a transmission case connected to an engine body mounted on a vehicle body frame, and constitutes a part of the drive pulley, and an electric motor for transmission mounted on the outer surface of the transmission case. A speed reduction gear mechanism housed in the transmission case is interposed between the movable pulley half and a drive gear fixed to the motor shaft of the speed change electric motor and an idle gear meshing with the drive gear. A power unit for a small vehicle in which a gear case that supports the speed reduction gear mechanism together with a case member that constitutes a part of the transmission case is attached to the case member. On.

By the way, in such a power unit, it is necessary to avoid as much as possible wear caused by dust entering the gear meshing portion of the speed reduction gear mechanism, and in particular, a drive gear provided on the motor shaft of the speed change electric motor, Since the meshing portion with the idle gear that meshes with the drive gear has a large number of meshes, it is necessary to prevent the dust from entering, and the drive gear and the idle gear are stored separately from other parts in the transmission case. Patent Document 1 discloses that a cover member that forms a reduction gear chamber that is formed between a reduction gear chamber and a transmission case is attached to the transmission case.
JP 2006-22928 A

  However, the one disclosed in Patent Document 1 requires a cover member separate from the transmission case in order to prevent dust from entering the meshing portions of the drive gear and the idle gear, and increases the number of parts. .

  The present invention has been made in view of such circumstances, and can prevent dust from entering the meshing portions of the drive gear and the idle gear in the speed reduction gear mechanism with a configuration that avoids an increase in the number of parts. It aims at providing the power unit for small vehicles.

  In order to achieve the above object, an invention according to claim 1 is characterized in that an endless shape is provided between a drive pulley attached to a rotary shaft that outputs rotational power of an engine and a driven pulley capable of transmitting rotational power to drive wheels. A V-belt continuously variable transmission formed by winding a V-belt is accommodated in a transmission case connected to an engine body mounted on a vehicle body frame, and is mounted on the outer surface of the transmission case. The transmission includes a driving gear fixed to a motor shaft of the electric motor for shifting and an idle gear meshing with the driving gear between a motor and a movable pulley half constituting a part of the drive pulley. A speed reduction gear mechanism housed in the case is interposed, and a gear case supporting the speed reduction gear mechanism together with a case member forming a part of the transmission case is the case portion. In the small vehicle power unit mounted on the case, the case member includes a protrusion that surrounds the meshing portion of the drive gear and the idle gear and that abuts against the gear case so as to protrude integrally with the gear case. To do.

  According to a second aspect of the invention, in addition to the configuration of the first aspect of the invention, the gear case is disposed outside the case member along the width direction of the body frame and is accommodated in the transmission case. It is characterized by that.

  According to a third aspect of the present invention, in addition to the configuration of the second aspect of the invention, the rotational position of the rotating member constituting a part of the speed reduction gear mechanism is detected to detect the axial position of the movable pulley half. A pulley position sensor for detecting the above is housed in the transmission case and attached to the gear case.

  According to a fourth aspect of the invention, in addition to the configuration of the first aspect of the invention, the idler integrally includes a first large diameter gear meshing with the drive gear and a first small diameter gear coaxial with the first large diameter gear. A gear, a second large-diameter gear that meshes with the first small-diameter gear, and a second small-diameter gear that is coaxial with the second large-diameter gear are integrally formed, and together with the idle gear constitute a part of the reduction gear mechanism for transmission. The second idle gear is arranged such that the first and second large diameter gears are positioned closer to the center in the width direction of the body frame than the first and second small diameter gears.

  Furthermore, in the invention of claim 5, in addition to the configuration of the invention of claim 4, the protrusion has a substantially C-shape opening a part where a part of the second large-diameter gear is arranged. It is characterized in that both ends in the circumferential direction are opposed to the outer periphery of the second large-diameter gear with a slight gap.

  The crankshaft 28 of the embodiment corresponds to the rotating shaft of the present invention, the inner case 56 of the embodiment corresponds to the case member of the present invention, and the first idle gear 114 of the embodiment corresponds to the idle gear of the present invention. The idle rotation shaft 118 of the embodiment corresponds to the rotation member of the present invention.

  According to the first aspect of the present invention, the gear case that supports the speed reduction gear mechanism is attached to the case member together with the case member that constitutes a part of the transmission case, and the meshing portion of the drive gear and the idle gear is provided. Since the projecting portion that surrounds and contacts the gear case protrudes toward the gear case side and is provided integrally with the case member, dust can be prevented from entering the meshing portion of the drive gear and idle gear simply by attaching the gear case to the case member. In addition, since a dedicated cover member for preventing dust intrusion is not required, an increase in the number of parts can be avoided.

  According to the second aspect of the invention, since the gear case is disposed outside the case member along the width direction of the vehicle body frame and is accommodated in the transmission case, the support structure of the speed reduction gear mechanism can be simplified. The speed reduction gear mechanism can be easily accommodated in the transmission case.

  According to the invention of claim 3, since the pulley position sensor for detecting the axial position of the movable pulley half is housed in the transmission case and attached to the gear case, the pulley position sensor can be easily protected, The appearance can be enhanced by preventing the pulley position sensor from being seen from the outside of the transmission case.

  According to the fourth aspect of the present invention, the idle gear having the first large-diameter gear that meshes with the drive gear of the motor shaft, the second large-diameter gear that meshes with the first small-diameter gear of the idle gear, and the second large-diameter gear. A second idle gear having a second small-diameter gear that rotates together with the gear is disposed so that the first and second large-diameter gears are positioned closer to the center in the width direction of the body frame than the first and second small-diameter gears. Therefore, the drive gear and the first large-diameter gear are disposed closer to the center of the body frame in the width direction than the second large-diameter gear, and the center of gravity of the transmission electric motor is closer to the center of the body frame in the width direction. It is possible to optimize the left and right weight balance of the power unit.

  According to a fifth aspect of the present invention, both ends in the circumferential direction of the protrusion formed in a substantially C-shape opening a portion where a part of the second large-diameter gear is disposed are the outer periphery of the second large-diameter gear. A sufficient dust intrusion preventing effect can be obtained while simplifying the structure for preventing dust from entering the meshing portions of the drive gear and the idle gear by facing each other with a slight gap therebetween.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

  1 to 8 show an embodiment of the present invention. FIG. 1 is a partially cutaway side view of a scooter type motorcycle, FIG. 2 is a sectional view taken along line 2-2 of FIG. 1, and FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 3, FIG. 5 is an enlarged view of a main part of FIG. 2, FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. 7 is a sectional view taken along line 7-7, and FIG. 8 is a sectional view taken along line 8-8 in FIG.

  First, in FIG. 1, a vehicle body frame F of a scooter type motorcycle includes a front fork 11 that pivotally supports a front wheel WF, a head pipe 13 that supports a steering handle 12 connected to the front fork 11 so as to be steerable, A main frame 14 extending rearward and downward from the head pipe 13, a pair of left and right pivot plates 15 connected to the rear portion of the main frame 14 and extending downward, and a pair of left and right shafts extending rearward and upward from the rear portion of the main frame 14. And a rear frame 17 connecting the intermediate portion of the pivot plate 15 and the rear portion of the seat rail 16. The engine hanger 18 protrudes downward from the intermediate portion of the main frame 14. Is provided.

  A front end portion of the swing arm 19 is supported on the middle portion of the pivot plate 15 so as to be able to swing up and down. A rear wheel WR is pivotally supported on the rear portion of the swing arm 19, and the rear portion of the swing arm 19 and the seat rail 16 A rear cushion unit 20 is provided between the rear portions.

  A power unit P is mounted on the body frame F. A storage box 21 disposed above the power unit P and a fuel tank 22 disposed behind the storage box 21 and above the rear wheel WR are supported by the seat rails 16, and the storage box 21 and the fuel tank 22 are supported. Is placed so as to cover the vehicle from above. Further, a synthetic resin vehicle body cover 24 covering the vehicle body frame F, the front portion of the power unit P, the storage box 21 and the fuel tank 22 is attached to the vehicle body frame F.

  In FIG. 2, the power unit P includes an engine E in which the cylinder axis C is inclined forward until it is substantially horizontal, and a V-belt type continuously variable transmission that continuously transmits the output of the engine E to the rear wheel WR. A transmission M is provided.

  The engine body 27 of the engine E includes a crankcase 29 that rotatably supports a crankshaft 28 having an axis parallel to the rotation axis of the rear wheel WR, a cylinder block 30 coupled to the crankcase 29, A cylinder head 31 coupled to the cylinder block 30 on the opposite side and a head cover 32 coupled to the cylinder head 31 on the opposite side to the cylinder block 30 are configured as a single cylinder. It consists of a pair of left and right case halves 29a and 29b that are coupled to each other at a coupling surface along a plane orthogonal to the axis of the shaft 28.

  The cylinder block 30 is coupled to the crankcase 29 such that the cylinder axis C slightly rises forward along the front-rear direction of the motorcycle and becomes substantially horizontal, and the piston 33 is slidably fitted to the cylinder block 30. Is connected to the crankshaft 28 via a connecting rod 34.

  As shown in FIG. 3, a bracket 35 is provided on the upper front side of the crankcase 29, and the bracket 35 is fastened to the engine hanger 18 of the vehicle body frame F so that the engine body 27 is suspended. Supported by an engine hanger 18. Further, as shown in FIG. 1, a pair of brackets 36 and 37 are provided at the rear portion of the crankcase 29 with a space therebetween in the vertical direction, and these brackets 36 and 37 are fastened to the pivot plate 15 of the vehicle body frame F. . Accordingly, the engine body 27, that is, the power unit P is mounted on the vehicle body frame F so as to be positioned below the vehicle body frame F between the front wheels WF and the rear wheels WR.

  An intake device 38 is connected to the upper side surface of the cylinder head 31 in the engine body 27, and the intake device 38 is supported by the main frame 14 of the vehicle body frame F above the head cover 32 in the engine body 27. A throttle body 40 connected to the air cleaner 39, and an intake pipe 41 having an upstream end connected to the throttle body 40 and a downstream end connected to the upper side surface of the cylinder head 31. A fuel injection valve 42 is attached.

  An exhaust pipe 43 is connected to the lower surface of the cylinder head 31. The exhaust pipe 43 extends rearward from the lower surface of the cylinder head 31 and is connected to an exhaust muffler 44 disposed on the right side of the rear wheel WR. Connected.

  Referring again to FIG. 2, an outer rotor 46 is fixed to the left end portion of the crankshaft 28 in a state where the motorcycle is directed forward, and an inner stator that constitutes the generator 45 in cooperation with the outer rotor 46. 47 is fixed to a generator cover 48 coupled to the crankcase 29 so as to surround the generator 45.

  Further, a gear 49 is supported on the crankshaft 28 inward of the generator 45 so as to be relatively rotatable, and power transmission from the gear 49 to the crankshaft 28 is allowed between the gear 49 and the crankshaft 28. In this way, the one-way clutch 50 is interposed.

  Thus, the gear 49 includes a starting electric motor 51 (see FIG. 1) for applying starting power to the crankshaft 28 and a part of the starting reduction gear mechanism 52 provided between the crankshafts 28. The starting electric motor 51 has a rotation axis parallel to the crankshaft 28 and is attached to the upper part of the crankcase 29 in the engine body 27 in front of the engine hanger 18.

  In FIG. 4, a mounting portion 129 for mounting the starter electric motor 51 from the right side is integrally provided on the left upper portion of the left case half 29a in the crankcase 29 of the engine body 27 so as to rise upward. The starting electric motor 51 is fastened to the mounting portion 129 so that the motor shaft 51a is inserted between the left case half 29a and the generator cover 48.

  Thus, the starting reduction gear mechanism 52 includes a drive gear 130 provided integrally with the motor shaft 51a of the starter electric motor 51, a large-diameter idle gear 131 that meshes with the drive gear 130, and a large-diameter idle gear. A small-diameter idle gear 132 that rotates together with the small-diameter idle gear 132 and the gear 49 that meshes with the small-diameter idle gear 132 are arranged on the left side of the cylinder axis C in a state of facing forward in the traveling direction of the motorcycle. . The small-diameter idle gear 132 is rotatably supported by a shaft 133 supported at both ends by the crankcase 29 and the generator cover 48, and the large-diameter idle gear 131 is fixed to the small-diameter idle gear 132 coaxially.

  In FIG. 2 again, the V-belt type continuously variable transmission M is accommodated in the transmission accommodation chamber 55 of the transmission case 54. The transmission case 54 is composed of a plurality of case members that are separate members from the engine body 27. In this embodiment, an inner case 56 coupled to the right case half 29b of the crankcase 29, The outer case 57 covers the inner case 56 from the outside, and is partly connected to the engine main body 27 so as to cover a part of the engine main body 27 from the right side with the motorcycle facing forward.

  The V-belt type continuously variable transmission M includes a drive pulley 58 mounted on the right end of the crankshaft 28 that enters the transmission chamber 55 from the crankcase 29, and a transmission rotation having an axis parallel to the crankshaft 28. A driven pulley 59 mounted on the shaft 61 and an endless V-belt 60 that transmits power from the drive pulley 58 to the driven pulley 59 are provided. The transmission rotating shaft 61 is an inner case of the transmission case 54. 56 and the right case half 29b of the crankcase 29 are rotatably supported.

  The drive pulley 58 includes a fixed pulley half 62 fixed to the crankshaft 28 and a movable pulley half 63 that can be moved toward and away from the fixed pulley half 62 so that the V-belt 60 is wound around the drive pulley 58. The width, that is, the winding radius of the belt groove 64 formed between the fixed pulley half 62 and the movable pulley half 63 changes depending on the approach and separation of the movable pulley half 63 to the fixed pulley half 62.

  Further, the driven pulley 59 is slidably fitted to the inner cylinder 65 that coaxially surrounds the transmission rotation shaft 61 so as to allow relative rotation, and to enable relative rotation around the axis and relative movement in the axial direction. An outer cylinder 66 to be fastened, a fixed pulley half 67 fixed to the inner cylinder 65, a movable pulley half 68 fixed to the outer cylinder 66 opposite to the fixed pulley half 67, and the movable pulley half 68 A torque cam mechanism 69 provided between the inner cylinder 65 and the outer cylinder 66 so that an axial component force acts between the pulley halves 67 and 68 in accordance with the relative rotational phase difference between the fixed pulley halves 67; A spring receiving member 70 fixed to the inner cylinder 65 at a position sandwiching the movable pulley half 68 between the fixed pulley half 67 and the movable pulley half 68 and the spring receiving member 70 surrounding the outer cylinder 66 Carp to be reduced to And a spring 71, V belt 60 is wound around the belt groove 72 formed between the fixed pulley half 67 and the movable pulley half 68.

  Thus, the distance between the fixed pulley half 67 and the movable pulley half 68 in the driven pulley 59 is such that the axial force generated by the torque cam mechanism 66, the axial elastic force generated by the coil spring 71, and the fixed pulley half. By determining the balance with the force from the V-belt 60 acting in the direction of separating the space between the body 67 and the movable pulley half 68, the movable pulley half 63 is brought close to the fixed pulley half 62 in the drive pulley 58. When the winding radius of the V belt 60 around the drive pulley 58 increases, the winding radius of the V belt 60 around the driven pulley 59 decreases.

  A clutch chamber 75 is formed between the inner case 56 in the transmission case 54 and the right case half 29 b in the crankcase 29, and a centrifugal clutch 76 is accommodated in the clutch chamber 75. The centrifugal clutch 76 is provided between the transmission rotation shaft 61 and a gear shaft 77 that is supported coaxially and relatively rotatably by the transmission transmission rotation shaft 61, and the engine speed is set to the set rotation speed. , The rotational power of the transmission rotating shaft 61 is transmitted to the gear shaft 77 via the centrifugal clutch 76.

  On the other hand, an idle rotation shaft 74 and an output shaft 78 parallel to the transmission rotation shaft 61 are rotatably supported on the crankcase 29, and one end portion of the idle rotation shaft 74 is inserted into the clutch chamber 75. . Thus, a reduction gear mechanism 79 is provided between the gear shaft 77 and the output shaft 78 so that rotational power is transmitted from the gear shaft 77 to the output shaft 78 via the idle rotation shaft 74. A drive sprocket 80 is fixed to the projecting end of the output shaft 78 from the left case half 29a of the crankcase 29. On the other hand, a driven sprocket 81 (see FIG. 1) is coaxially fixed to the rear wheel WR, and an endless chain 82 is wound around the drive sprocket 80 and the driven sprocket 81.

  Referring also to FIG. 5, an annular stepped portion 28a is formed on the crankshaft 28 at the portion protruding from the right case half 26b of the crankcase 26. Between the nut 84 screwed into the end portion of the crankshaft 28 and the annular step portion 28a, the crankshaft 28 has a cylindrical first sleeve 85, a ball bearing in order from the annular step portion 28a side. 86, an inner ring 86, a cylindrical second sleeve 87, a cylindrical connecting tube portion 88, a cylindrical third sleeve 89, a fixed pulley half 62 and a washer 90 are mounted, and a fixed pulley by tightening a nut 84 The half body 62 is fixed to the crankshaft 28, and the inner periphery of the connecting cylinder portion 88 is splined to the outer periphery of the crankshaft 28. The first sleeve 85 passes through the inner case 56 of the transmission case 54 in a rotatable manner, and an annular seal member 91 is interposed between the first sleeve 85 and the inner case 56.

  The movable pulley half 63 of the drive pulley 58 has a cylindrical portion 63 a integrally surrounding the second sleeve 87, the connecting cylindrical portion 88 and the second sleeve 89 and spline-coupled to the outer periphery of the connecting cylindrical portion 88. Thus, the movable pulley half 63 is mounted on the crankshaft 28 so as not to allow relative rotation around the axis and to allow movement in the axial direction.

  In order to drive the movable pulley half 63 of the drive pulley 58 in the axial direction, an axially fixed side cylinder member 93 is supported on the crankshaft 28 so as not to move in the axial direction and is coaxially and relatively rotatable. An axially movable side tubular member 94 disposed coaxially with the fixed side tubular member 93 is held by the movable pulley half 63 so as not to rotate around its axis, and the axially fixed side tubular member 93 and the axially movable side are disposed. A screw feed mechanism 95 is provided between the cylindrical members 94, and rotational power is transmitted to the axially fixed side cylindrical member 93 from a transmission electric motor 96 attached to the transmission case 54 via a transmission reduction gear mechanism 97. Is done.

  The ball bearing 86 is interposed between the axially fixed side cylinder member 93 and the crankshaft 28 at the end opposite to the movable pulley half 63, so that the crankshaft 28 is relatively rotatable. In addition, the outer periphery of a ring-shaped support member 98 that is supported so as not to move in the axial direction is fixed, and the cylindrical member 93 on the axially fixed side is supported on the crankshaft 28 so that it cannot move in the axial direction. Will be.

  The axially movable side cylindrical member 94 is formed in a cylindrical shape so as to be coaxially inserted into the axially fixed side cylindrical member 93, and the screw feed mechanism 95 is an axially fixed side cylindrical member. 93 is provided between the inner periphery of 93 and the outer periphery of the axially movable side cylinder member 94. Moreover, the axially movable side cylindrical member 94 is held by the movable pulley half 63 via the ball bearing 99, and the movable pulley half 63 moves in the axial direction together with the axially movable side cylindrical member 94.

  A cylindrical member 100 surrounding the axially fixed side cylindrical member 93 is fixed to the axially movable side cylindrical member 94, and the outer periphery of the axially fixed side cylindrical member 93 is in sliding contact with the inner periphery of the cylindrical member 100. An annular seal member 101 is attached. Thus, the cylindrical member 100 is engaged with the transmission case 54 so that the cylinder member 100 can move in the direction along the axis of the crankshaft 28, but is prevented from rotating around the axis of the crankshaft 28. Thus, the axially movable side cylinder member 94 is allowed to move in the axial direction of the crankshaft 28, but is prevented from rotating around the axis of the crankshaft 28.

  An inner case 56 and an outer case 57 constituting a part of the transmission case 54 are formed so that a part thereof protrudes above the cylinder block 30 from the crankcase 29 in a side view of the engine body 27. A through hole 102 having an axis parallel to the crankshaft 28 is provided in a portion of the inner case 56 that protrudes above the cylinder block 30.

  Further, on the outer surface of the inner case 56, a mounting plate 103 having a cylindrical portion 103a fitted in the through hole 102 in an airtight manner is fastened by a plurality of bolts 104, and a motor shaft 105 having an axis parallel to the crankshaft 28 is secured. A transmission electric motor 96 having the above is fixed to the mounting plate 103, and the motor shaft 105 penetrates the cylindrical portion 103 a and enters the transmission case 54.

  As shown in FIG. 3, the transmission electric motor 96 is surrounded by the intake device 38 connected to the upper side wall of the cylinder head 31 in the engine body 27, the main frame 14 in the body frame F, and the engine body 27. The engine block 27 is disposed in front of the engine hanger 18 provided in the middle portion of the main frame 14 to suspend the engine body 27, and in particular, the cylinder block 30 constituting a part of the engine body 27. Above the starting electric motor 51 and the intake device 38. Thus, the starting electric motor 51 is attached to the attaching portion 129 of the case half 29a in the crankcase 29 from the right in the left-right direction of the body frame F, whereas the speed changing electric motor 96 is used for the body frame. F is attached to the inner case 56 of the transmission case 54 from the left side in the left-right direction.

  By the way, the fuel injection valve 42 is attached to the throttle body 40 of the intake device 38 so that the axis CF thereof is substantially along the vertical direction. The fuel injection valve 42 is attached to a portion facing the motor 51 side. The speed change electric motor 96 is arranged below a straight line L connecting the upper end of the fuel injection valve 42 and the rotation axis of the starter electric motor 51 in a side view. In addition, the starting electric motor 51 and the shifting electric motor 96 having a rotation axis parallel to the axis of the crankshaft 28 are centered in the axial direction at the center of the engine body 27 in the direction along the axis of the crankshaft 28. In this embodiment in which the engine body 27 is configured as a single cylinder, the axially central portions of the starting electric motor 51 and the shifting electric motor 96 are located near the cylinder axis C as shown in FIG. Be placed.

  Referring also to FIG. 6, the speed reduction gear mechanism 97 includes a first large diameter gear 107 that meshes with a drive gear 106 fixed to the motor shaft 105 of the speed change electric motor 96, and a first large diameter. First small-diameter gear 108 that rotates together with gear 107, second large-diameter gear 109 that meshes with first small-diameter gear 108, second small-diameter gear 110 that rotates together with second large-diameter gear 109, and second small-diameter gear 110 It is comprised with the driven gear 111 integrally provided in the axial direction fixed side cylinder member 93 so that it may mesh | engage, and is arrange | positioned on the right side rather than the cylinder axis C in the state which faced the front of the advancing direction of the motorcycle. . That is, the starting reduction gear mechanism 52 and the transmission reduction gear mechanism 97 are arranged on opposite sides of the cylinder axis C in the direction along the axis of the crankshaft 28.

  The speed reduction gear mechanism 97 is disposed on the outer side of the inner case 56 in the width direction of the vehicle body frame F, that is, in the left-right direction of the motorcycle, and constitutes a part of the transmission case 54. 56 is accommodated in a transmission case 56 so as to be supported by a gear case 113 fastened by a plurality of bolts 112.

  The first large-diameter gear 107 and the first small-diameter gear 108 are integrally formed to constitute the first idle gear 114. The shaft portion 114a that the first idle gear 114 has integrally includes the inner case 56 and the first idle gear 114. The gear case 113 is rotatably supported via ball bearings 115 and 116. The second large-diameter gear 109 and the second small-diameter gear 110 are integrally formed to constitute the second idle gear 117. The second idle gear 117 is provided with a ball bearing 119 on the inner case 56 and the gear case 113. , 120 is fixed to an idle rotation shaft 118 rotatably supported.

  In addition, the first and second idle gears 114 and 117 are arranged so that the first and second large diameter gears 107 and 109 are located in the width direction center side of the vehicle body frame F, that is, the engine main body 27 side than the first and second small diameter gears 108 and 110. And is supported by the inner case 56 and the gear case 113.

  In the inner case 56, a protrusion 56 a that protrudes toward the gear case 113 so as to contact the gear case 113 surrounds the meshing portion of the drive gear 106 and the first large-diameter gear 107 of the first idle gear 114. The gear case 113 is integrally provided with a protrusion 113 a that contacts the protrusion 56 a of the inner case 56.

  By the way, the first small-diameter gear 108 of the first idle gear 114 meshes with the second large-diameter gear 109 of the second idle gear 117, so that the projections 56a and 113a are formed on the drive gear 106 and the first idle gear 117 as a whole. Rather than encircling, the second idle gear 117 is formed to avoid interference with the second large diameter gear 109 and the second small diameter gear 110. That is, as shown in FIG. 7, the protrusion 56a of the inner case 56 is substantially C-shaped with a portion where the part of the second large-diameter gear 109 is disposed, and both ends in the circumferential direction are second large. The shape is formed as close as possible to the outer periphery of the radial gear 109. Further, as shown in FIG. 8, the protrusion 113 a of the gear case 113 has a substantially C-shape with an opening where a part of the second small-diameter gear 110 is disposed, and both ends in the circumferential direction of the second small-diameter gear 110. It is formed in the shape which extended the circumferential direction both ends to the circumferential direction rather than the protrusion 56a of the inner side case 56 so that it may be brought close to the outer periphery as much as possible.

  Paying attention to FIG. 6, a pulley position sensor that detects the amount of rotation of the idle rotation shaft 118 that forms part of the speed reduction gear mechanism 97 and detects the axial position of the movable pulley half 63 in the drive pulley 58. 121 is accommodated in the transmission case 54 and attached to the gear case 113.

  The gear case 113 is integrally provided with a support protrusion 113b that allows one end of the idle rotation shaft 118 to enter, and an intermediate portion of the idle rotation shaft 118 is interposed between the support protrusion and the ball bearing 120. 113b is rotatably supported.

  A worm 122 is provided at one end of the idle rotation shaft 118 in the support protrusion 113b, and the pulley position sensor 121 has a detection shaft 123 extending in a direction orthogonal to the idle rotation shaft 118. A worm wheel 124 that is attached to the support protrusion 113 b and meshes with the worm 122 is provided on the detection shaft 123.

  Next, the operation of this embodiment will be described. A V-belt type continuously variable transmission M is accommodated in a transmission case 54 connected to the engine body 27, and a part of a drive pulley 58 in the continuously variable transmission M is described. A speed reduction gear mechanism 97 is interposed between the movable pulley half 63 and the speed change electric motor 96, and is arranged on the upper side wall of the cylinder head 31 constituting a part of the engine body 27. A speed change electric motor 96 is disposed in front of the engine hanger 18 in a region surrounded by the intake device 38 to be connected, the main frame 14 provided with the engine hanger 18 in the body frame F, and the engine body 27. Therefore, it is possible to effectively arrange the speed change electric motor 96 in an empty space where no other parts are arranged to reduce the degree of freedom in arrangement of the parts around the power unit P. The shifting electric motor 96 can be arranged close to the center in the width direction of the vehicle body frame F to optimize the weight balance of the power unit P, and the shifting electric motor 96 overlaps the engine hanger 18 in a side view. Therefore, the maintenance work of the transmission electric motor 96 is facilitated.

  A starter electric motor 51 capable of applying starter power to the crankshaft 28 is attached to the upper part of the crankcase 29 in the engine body 27 in front of the engine hanger 18, and the speed change electric motor 96 is connected to the engine body 27. Is disposed between the starting electric motor 51 and the intake device 38 above the cylinder block 30 which is a part of the vehicle body frame F, so that the starting electric motor 51 which is a heavy object is also brought closer to the center of the body frame F in the width direction. It is possible to effectively arrange the power unit P in the empty space and further optimize the weight balance of the power unit P.

  Further, since the fuel injection valve 42 is attached to a portion of the intake device 38 facing the shift electric motor 96 and the start electric motor 51 side, the shift electric motor 96, the start electric motor 51 and the fuel injection valve 42 are electrically connected. Therefore, it is possible to consolidate the wirings connected to each other and facilitate the wiring.

  In addition, the transmission electric motor 96 and the starter electric motor 51 are attached to the engine body 27 so that the rotation axis is along the width direction of the vehicle body frame F, and the transmission reduction gear mechanism 97 and the starter motor 51 are started. Since the starter reduction gear mechanism 52 provided between the electric motor 51 and the crankshaft 28 is disposed on the opposite side along the axis of the crankshaft 28 so as to sandwich the cylinder axis C therebetween, the power unit P The right and left weight balance can be further optimized and the power unit P can be made compact.

  Further, since the shifting electric motor 96 is disposed below the straight line L connecting the upper end of the fuel injection valve 42 and the rotation axis of the starting electric motor 51 in a side view, the fuel injection valve 42 and the starting electric motor 51 The speed change electric motor 96 can be effectively disposed in the formed recess.

  Further, the central portion along the rotation axis of the electric motor for shifting 96 and the electric motor for starting 51 in which the rotation axis is along the width direction of the vehicle body frame F is arranged along the axis of the crankshaft 28. Since the power unit P is disposed substantially at the center, it is possible to further optimize the right and left weight balance of the power unit P and further reduce the size of the power unit P.

  A gear case 113 that supports a speed reduction gear mechanism 97 together with an inner case member 56 that constitutes a part of the transmission case 54 is attached to the inner case 56 and fixed to the motor shaft 105 of the speed change electric motor 96. A projection 56 a that surrounds the meshing portion of the drive gear 106 and the first large-diameter gear 107 in the first idle gear 114 and contacts the gear case 113 protrudes toward the gear case 113 and is provided integrally with the inner case 56. Therefore, it is possible to prevent dust from entering the meshing portion of the drive gear 106 and the first idle gear 114 simply by attaching the gear case 113 to the inner case 56, and a dedicated cover member for preventing dust intrusion is unnecessary. As a result, an increase in the number of parts can be avoided.

  Moreover, the protrusion 56a is substantially C-shaped with an opening in the second idle gear 117 where a part of the second large-diameter gear 109 is disposed, and both ends in the circumferential direction are the outer periphery of the second large-diameter gear 109. Therefore, both ends of the protrusion 56a in the circumferential direction are opposed to the outer periphery of the second large-diameter gear 109 with a slight gap therebetween, so that the drive gear It is possible to obtain a sufficient dust intrusion preventing effect while simplifying the structure for preventing dust from entering the meshing portion between the first idle gear 114 and the first large-diameter gear 107 of the first idle gear 114.

  Further, the gear case 113 is disposed outside the inner case member 56 along the width direction of the vehicle body frame F and is accommodated in the transmission case 54, so that the support structure of the speed reduction gear mechanism 97 is simplified. The speed reduction gear mechanism 97 can be easily accommodated in the transmission case 54.

  A pulley position sensor 121 that detects the amount of rotation of the idle rotation shaft 118 that constitutes a part of the speed reduction gear mechanism 97 and detects the axial position of the movable pulley half 63 is housed in the transmission case 54. Since it is attached to the gear case 113, the pulley position sensor 121 can be easily protected, and the appearance can be enhanced by preventing the pulley position sensor 121 from being seen from the outside of the transmission case 54.

  The transmission reduction gear mechanism 97 includes a first idler gear 114 integrally having a first large-diameter gear 107 meshed with the drive gear 106, a first small-diameter gear 108 coaxial with the first large-diameter gear 107, and a first idle gear 114. The second large-diameter gear 109 meshed with the small-diameter gear 108 and the second large-diameter gear 109 and the second idle gear 117 integrally having the second small-diameter gear 110 coaxial with the second large-diameter gear 109 are included. Since the two idle gears 114 and 117 are arranged so that the first and second large diameter gears 107 and 109 are positioned closer to the center in the width direction of the vehicle body frame F than the first and second small diameter gears 108 and 110, The drive gear 106 and the first large diameter gear 107 are disposed closer to the center in the width direction of the vehicle body frame F than the second large diameter gear 109. By placing the heart in a position closer to the widthwise center of the vehicle body frame F, it is possible to optimize the weight balance between the left and right of the power unit P.

  Moreover, since the speed reduction gear mechanism 97 and the start speed reduction gear mechanism 52 are disposed on opposite sides of the cylinder shaft C along the axis of the crankshaft 28, the left and right weight balance of the power unit P is determined. This can contribute to the optimization of the power unit P and also to the compactness of the power unit P.

  The transmission case 54 includes inner and outer cases 56 and 57 that are independent from the engine main body 27, and the transmission electric motor 96 is attached to the outer surface of the transmission case 54, so that the structure of the engine main body 27 is complicated. It becomes easy to arrange the center of gravity of the transmission electric motor 96 close to the center in the width direction of the vehicle body frame F without making it change, and the vibration of the engine body 27 is transmitted to the transmission case 54 and the transmission electric motor 96. Since it becomes difficult, the slide operability of the movable pulley half 63 in the drive pulley 58 can be enhanced.

  Further, since the speed reduction gear mechanism 97 is housed in the transmission case 54 and supported by the transmission case 54, the engine main body can be applied to a power unit that does not use the speed change electric motor 96 and the speed reduction speed gear mechanism 97. 27 can be shared.

  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. It is.

  For example, the motorcycle has been described in the above embodiment, but the present invention is widely applicable to small vehicles such as motorcycles and motorcycles.

1 is a partially cutaway side view of a scooter type motorcycle. FIG. 2 is a sectional view taken along line 2-2 of FIG. It is a principal part enlarged view of FIG. FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. FIG. 3 is an enlarged view of a main part of FIG. 2. FIG. 6 is a sectional view taken along line 6-6 of FIG. FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. 5. FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 5.

Explanation of symbols

27 ... Engine body 28 ... Crankshaft 54 as a rotating shaft ... Transmission case 56 ... Inner case 56a as a case member ... Projection 58 ... Drive pulley 59 ... Driven Pulley 60 ... V belt 63 ... movable pulley half 97 ... speed reduction gear mechanism 96 ... speed change electric motor 105 ... motor shaft 106 ... drive gear 107 ... first Large diameter gear 108 ... first small diameter gear 109 ... second large diameter gear 110 ... second small diameter gear 113 ... gear case 114 ... first idle gear 117 as an idle gear ... first 2 idle gear 118 ... idle rotation shaft 121 which is a rotating member ... pulley position sensor E ... engine F ... body frame M ... continuously variable transmission P ... power unit WR ... drive The rear wheel is a wheel

Claims (5)

  An endless V is connected to a drive pulley (58) mounted on a rotary shaft (28) that outputs rotational power of the engine (E) and a driven pulley (59) that can transmit rotational power to the drive wheels (WR). A V-belt type continuously variable transmission (M) around which a belt (60) is wound is accommodated in a transmission case (54) connected to an engine body (27) mounted on a vehicle body frame (F). Between the transmission electric motor (96) attached to the outer surface of the transmission case (54) and the movable pulley half (63) constituting a part of the drive pulley (58). A shift gear housed in the transmission case (54) including a drive gear (106) fixed to the motor shaft (105) of the electric motor (96) and an idle gear (114) meshing with the drive gear (106). Reduction gear mechanism (9 ) And a gear case (113) supporting the speed reduction gear mechanism (97) together with a case member (56) constituting a part of the transmission case (54) is attached to the case member (56). In the small vehicle power unit, the case member (56) has a protrusion (56a) surrounding the meshing portion of the drive gear (106) and the idle gear (114) and contacting the gear case (113). A power unit for a small vehicle, characterized in that it protrudes toward the gear case (113) and is provided integrally therewith.   The gear case (113) is disposed outside the case member (56) along the width direction of the body frame (F) and is accommodated in the transmission case (54). The power unit for small vehicles as described.   A pulley position sensor (121) for detecting a rotation amount of a rotating member (118) constituting a part of the speed reduction gear mechanism (97) and detecting an axial position of the movable pulley half (63); The power unit for a small vehicle according to claim 2, wherein the power unit is mounted in the transmission case (54) and attached to the gear case (113).   A first large-diameter gear (107) meshing with the drive gear (106), and the idle gear (114) integrally including a first small-diameter gear (108) coaxial with the first large-diameter gear (107); The second large-diameter gear (109) meshed with the small-diameter gear (108) and the second large-diameter gear (109) and the second small-diameter gear (110) coaxial with the second large-diameter gear (109) are integrated with the idle gear (114) and the speed change. The second idle gear (117) constituting a part of the reduction gear mechanism (97) for the first and second larger diameter gears (107, 109) than the first and second small diameter gears (108, 110) 2. The power unit for small vehicles according to claim 1, wherein the power unit is disposed so as to be positioned on the center side in the width direction of the vehicle body frame (F).   The protrusion (56a) is substantially C-shaped with an opening where a part of the second large-diameter gear (109) is disposed, and both circumferential ends thereof are on the outer periphery of the second large-diameter gear (109). 5. The power unit for a small vehicle according to claim 4, wherein the power unit is formed to face each other with a slight gap.

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