JP6487887B2 - Power transmission device - Google Patents

Description

  The present invention is a clutch outer connected to the power input side and holding a friction plate, a clutch hub which is supported rotatably relative to the clutch outer and holds a clutch plate which can be frictionally joined to the friction plate, An active gear connected to the clutch hub and having a first engagement portion and a coaxial engagement with the active gear so as to be displaceable in the axial direction, and the first engagement when moved from the axial reference position to the operating position in the axial direction The present invention relates to a power transmission device including a driven gear having a second engaging portion engaged with the portion and a shift drum having a cam profile for driving an active gear in the axial direction.

  Patent Document 1 discloses a dog clutch type transmission. In the dog clutch type transmission, the first engagement portion of the active gear meshes with the second engagement portion of the driven gear in transmitting power. Thus, the power of the input shaft is transmitted from the active gear to the driven gear of the output shaft via the driven gear. In Patent Document 1, even when the first engagement portion hits the second engagement portion and the axial movement of the active gear is prevented, the electric actuator causes relative rotation between the active gear and the driven gear. The first engaging portion can surely enter the adjacent space of the second engaging portion.

JP 2014-035064 A

  In Patent Document 1, although the coupling state is smoothly established between the first engaging portion and the second engaging portion as described above, the structure is complicated because the electric actuator is used to generate the relative rotation. At the same time, procurement costs and manufacturing costs also increase.

  An object of the present invention is to provide a power transmission device having a simple structure and capable of smoothly establishing a coupling state between a first engaging portion of an active gear and a second engaging portion of a driven gear. To do.

  According to the first aspect of the present invention, a clutch outer that is connected to the power input side and holds the friction plate, and a clutch that is rotatably supported relative to the clutch outer and can be frictionally joined to the friction plate. A clutch hub for holding a plate, an active gear coupled to the clutch hub and having a first engagement portion, and supported coaxially by the active gear so as to be axially displaceable, axially from an axial reference position A driven gear having a second engaging portion that engages with the first engaging portion when moved to the operating position, and a plurality of transmission gears that are changed by a combination of the active gear and the driven gear. In the power transmission device including a shift drum for operating a gear, the shift drum is formed with a plurality of cam grooves, and a sliding surface configured to contact the outer clutch. A member engages with the clutch hub, and an arm member that drives the sliding member is coupled to the cam groove. The arm member drives the sliding member and moves the clutch in accordance with the operation of the shift drum. A power transmission device that contacts the outer is provided.

  According to the second aspect, in addition to the configuration of the first side surface, the arm member is configured on the shift drum when the shift drum is in a neutral position where the active gear and the driven gear are not engaged. It is operated by the cam groove.

  According to the third aspect, in addition to the configuration of the first or second side surface, the shift drum is engaged with a first shift drum for operating the transmission gear and an end portion of the first shift drum. A cam groove configured to operate the arm member on the second shift drum, and a crankcase that supports the shift drum is interposed between the first shift drum and the second shift drum. Be placed.

  According to the fourth aspect, in addition to the configuration of the third side surface, the first shift drum is engaged with a shift fork that operates a transmission gear, and a fork shaft that supports the shift fork is disposed in the crankcase. The fork shaft passes through the crankcase and supports the arm member on the second shift drum side of the crankcase in the left-right direction.

  According to the fifth aspect, in addition to the configuration of any one of the first to fourth side surfaces, an elastic member is disposed on the sliding member, and the arm member is sandwiched between the elastic member and the sliding member. ing.

  According to the sixth aspect, in addition to the configuration of the fifth side face, a return spring is disposed on the clutch hub, and the return spring applies an urging force in a direction away from the outer clutch to the sliding member.

  According to the seventh aspect, in addition to the configuration of the second aspect, the power transmission device includes a first shaft that supports a drive gear or a driven gear including the active gear and the driven gear, and the drive gear or the In a multi-stage transmission including a driven gear that can mesh with the driven gear or a second shaft that supports the driving gear, a neutral state is established that cuts off transmission of power between the first shaft and the second shaft, When friction welding is established between the friction plate and the clutch plate, the friction circuit is connected again to the control circuit for stopping the combustion operation of the engine and the crankshaft of the engine and is released again in the neutral state. A starter motor for automatically starting a crankshaft in response to a command signal from the control circuit.

  According to the first aspect, when the shift drum moves to a specific position, the arm member operates the sliding member to contact the outer clutch. As a result, it is possible to create a situation in which part of the power is transmitted and the accompanying movement is likely to occur. Therefore, the active gear rotates by receiving power from the clutch hub. A relative rotation is thus caused between the active gear and the driven gear. When the active gear moves from the axial reference position to the operating position, even if the first engagement portion hits the second engagement portion and the axial movement of the active gear is prevented, the first engagement portion is It is possible to enter the adjacent space of the second engaging portion. Thus, a coupling state can be smoothly established between the first engagement portion and the second engagement portion.

  According to the second aspect, when the shift drum is in the neutral position, the active gear and the driven gear are not engaged, and in this state, when the connection between the friction plate and the clutch plate is released, the clutch The hub and the active gear are not engaged with the power source or the output destination. Even in such a case, according to the present structure, a part of the power can be transmitted to the clutch hub, so that the first engagement portion and the second engagement portion can be coupled. Thereafter, the operation of the arm member and the sliding member can be canceled by operating the shift drum.

  According to the third aspect, the intermediate portion between the first shift drum and the second shift drum is supported by dividing the shift drum into the first shift drum and the second shift drum and disposing the crankcase therebetween. Therefore, the shift drum can be firmly supported. Since the shift drum is arranged on one side and the clutch mechanism is arranged on the other side of the crankcase, the structure of the arm member is simplified by arranging the second shift drum in the vicinity of the clutch mechanism of the crankcase. And the crankcase can be configured simply.

  According to the fourth aspect, the number of parts can be reduced by sharing the shaft, and the shaft can be firmly supported by penetrating the crankcase.

  According to the fifth aspect, by sandwiching the arm member between the elastic member and the sliding member, the arm member can be operated relative to the sliding member, and even if the sliding member vibrates due to vibration or the like from the outside, the vibration is generated. It is difficult to transmit to the arm member. In addition, the friction load on the sliding member can be reduced.

  According to the sixth aspect, it is possible to reduce the contact between the sliding member and the clutch outer during non-operation due to vehicle body vibration or the like.

  According to the seventh aspect, after the friction clutch including the friction plate and the clutch plate is disconnected and the neutral state is established in the multi-stage transmission, when the friction clutch shifts to the connected state again, the engine performs an idle stop, The engine combustion operation stops. At this time, since the driving force is not input to the input shaft that supports the driving gear, the rotation of the driving gear stops. At the time of idling stop, since the driving force is not input to the output shaft that supports the driven gear, the rotation of the driven gear is also stopped. Thereafter, when the frictional connection is released again and the friction clutch is disconnected, the starter motor drives the crankshaft, and then the outer clutch rotates. Since the sliding member is in contact with the outer clutch because it is in the neutral state, relative rotation is caused between the active gear and the driven gear, so the first engaging portion is adjacent to the second engaging portion. Can enter. Thus, a coupling state can be smoothly established between the first engagement portion and the second engagement portion.

1 is a side view of a motorcycle. FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. It is an expanded partial sectional view showing the composition of a multi-stage transmission in detail. FIG. 3 is an enlarged partial cross-sectional view schematically showing a configuration of a shift mechanism and a clutch of a multi-stage transmission. It is a side view of the multistage transmission which shows the shape of an arm member.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Here, the top, bottom, front, back, left and right of the vehicle body are defined based on the eyes of the occupant riding the motorcycle.

  FIG. 1 schematically shows the overall configuration of a motorcycle according to an embodiment of the present invention. The motorcycle 11 includes a body frame 12. A front fork 14 is supported by the head pipe 13 at the front end of the body frame 12 so as to be steerable. A front wheel WF is supported on the front fork 14 so as to be rotatable around the axle 15. A swing arm 17 is supported on the pivot frame 16 at the rear end of the body frame 12 so as to be swingable about a support shaft 18 extending horizontally in the vehicle width direction. A rear wheel WR is supported at the rear end of the swing arm 17 so as to be rotatable around the axle 19.

  A handle bar 21 is coupled to the front fork 14 above the head pipe 13. A grip 22 is attached to the left and right ends of the handle bar 21. When traveling, the driver of the motorcycle 11 holds the grip 22 with the left and right hands. A clutch lever 23 is combined with the left grip 22. The driver can operate the clutch lever 23 with the left hand.

  An engine 25 is mounted on the body frame 12 between the front wheel WF and the rear wheel WR. The engine 25 includes a crankcase 26, a cylinder block 27 coupled to the crankcase 26, a cylinder head 28 coupled to the cylinder block 27, and a head cover 29 coupled to the cylinder head 28. The crankcase 26 accommodates a crankshaft 31 that rotates about an axis extending parallel to the axle 19 of the rear wheel WR. The crankshaft 31 rotates according to the axial movement of a piston (not shown) that is slidably fitted to the cylinder bore of the cylinder block 27. The rotational motion of the crankshaft 31 is transmitted to the drive sprocket 32 through a power transmission device described later. The rotational motion of the drive sprocket 32 is transmitted to the driven sprocket 34 fixed to the rear wheel WR via the drive chain 33.

  A fuel tank 35 is mounted on the body frame 12 above the engine 25. A passenger seat 36 is mounted on the vehicle body frame 12 behind the fuel tank 35. Fuel is supplied from the fuel tank 35 to the fuel injection device of the engine 25. When driving the motorcycle 11, the occupant straddles the occupant seat 36.

  As shown in FIG. 2, the crankcase 26 includes a first case half 26a and a second case half 26b. The crankshaft 31 is rotatably supported by the first case half 26a and the second case half 26b by bearings 37 fitted into the first case half 26a and the second case half 26b, respectively. A connecting rod 38 is connected to the crankshaft 31 crank in the crankcase 26. The connecting rod 38 converts the axial movement of the piston into the rotational movement of the crankshaft 31.

  A dog clutch type multi-stage transmission (power transmission device) 39 is incorporated in the engine 25. The multi-stage transmission 39 includes an input shaft 41 and an output shaft 42 having an axis parallel to the axis of the crankshaft 31. The input shaft 41 and the output shaft 42 are rotatably supported by the first case half 26a and the second case half 26b by bearings 43 and 44 that are fitted into the first case half 26a and the second case half 26b, respectively. The The input shaft 41 is connected to the crankshaft 31 through the primary reduction mechanism 45. The primary reduction mechanism 45 includes a drive gear 45a fixed to the crankshaft 31 and a driven gear 45b supported on the output shaft 42 so as to be relatively rotatable. The driven gear 45b meshes with the driving gear 45a. A drive sprocket 32 is coupled to the output shaft 42.

  Four drive gears are arranged on the input shaft 41. The drive gear includes a low drive gear 46, a fourth speed drive gear 47, a third speed drive gear 48, and a second speed drive gear 49 in order. Similarly, four driven gears are arranged on the output shaft 42 in order. The driven gear includes a low driven gear 51, a fourth speed driven gear 52, a third speed driven gear 53 and a second speed driven gear 54. In the multi-stage transmission 39, the coupling state is selectively switched between the neutral state, the first speed coupling state, the second speed coupling state, the third speed coupling state, and the fourth speed coupling state. Details of the multi-stage transmission 39 will be described later.

  A friction clutch 55 is incorporated in the engine 25. The friction clutch 55 includes a clutch outer 56 and a clutch hub 57. The driven gear 45 b of the primary reduction mechanism 45 is connected to the clutch outer 56. In accordance with the operation of the clutch lever 23, the friction clutch 55 is switched between connection and disconnection between the clutch outer 56 and the clutch hub 57. Details of the friction clutch 55 will be described later.

  An ACG (alternator) starter 58 is incorporated in the engine 25. The ACG starter 58 includes a rotor 59 and a stator 61. The rotor 59 is coupled to the crankshaft 31 protruding from the first case half 26a of the crankcase 26. The rotor 59 has a plurality of magnets arranged in the circumferential direction. The rotor 59 surrounds the outer periphery of the stator 61. A plurality of coils arranged in the circumferential direction are wound around the stator 61. The coil follows a path that faces the path of the magnet when the rotor 59 rotates. A generator cover 62 is coupled to the first case half 26 a of the crankcase 26. The stator 61 is supported by the generator cover 62. The rotor 59 and the stator 61 are accommodated in a space defined by the generator cover 62 and the first case half 26a. The ACG starter 58 functions as a starter motor that automatically starts the crankshaft 31 when the engine 25 is started. When the start of the engine 25 is confirmed, the ACG starter 58 functions as an AC generator.

  A control circuit is connected to the ACG starter 58. The control circuit is composed of, for example, an ECU (electronic control unit). The control circuit can execute idle stop control according to a control program (software) stored in a built-in storage device, for example. In executing the idle stop control, the control circuit establishes a neutral state in which the transmission of power is cut between the input shaft 41 and the output shaft 42, and when frictional connection is established between the friction plate and the clutch plate, Outputs a signal to stop the combustion operation. Thereafter, when the friction welding is released again in the neutral state, the control circuit supplies a command signal for instructing the operation of the starter motor to the ACG starter 58.

  As shown in FIG. 3, in the multi-stage transmission 39, the low drive gear 46 is carved on the input shaft 41. The 4-speed drive gear 47 is supported by the input shaft 41 so as to be rotatable relative to the input shaft 41 and not axially displaceable. The third speed drive gear 48 is integrated with the first shifter 64. The first shifter 64 is fitted into a spline 65 carved in the input shaft 41 and is supported on the spline 65 so as not to be relatively rotatable and to be axially displaceable. The second-speed drive gear 49 is supported by the input shaft 41 so as to be rotatable relative to the input shaft 41 but not axially displaceable.

  A first fitting mechanism 66 is configured between the fourth speed drive gear 47 and the third speed drive gear 48. The first fitting mechanism 66 includes a plurality of driving protrusions 67 formed on the first shifter 64 and a plurality of driven protrusions 68 formed on the fourth speed driving gear 47. When the first shifter 64 is positioned at the axial reference position on the spline 65, the trajectory of the driving projection 67 is separated from the trajectory of the driven projection 68. At this time, relative rotation between the fourth speed drive gear 47 and the first shifter 64 is allowed around the axis of the input shaft 41. When the first shifter 64 is displaced from the axial reference position toward the fourth speed drive gear 47 by the first distance and moved to the first operation position, the drive protrusion 67 is adjacent to the circumferential direction on the fourth speed drive gear 47. It enters between the driven protrusions 68. The driving protrusion 67 is in surface contact with the driven protrusion 68 in the rotation direction of the input shaft 41. The driving protrusion 67 and the driven protrusion 68 each have a contact surface that extends in a virtual plane including the axis of the input shaft 41. Thus, the driven protrusion 68 and the driving protrusion 67 mesh with each other around the axis of the input shaft 41. At the time of meshing, the 4-speed drive gear 47 is coupled to the input shaft 41 through the first shifter 64 so as not to be relatively rotatable.

  A second fitting mechanism 69 is configured between the third speed drive gear 48 and the second speed drive gear 49. The second fitting mechanism 69 includes a plurality of driving protrusions 71 formed on the first shifter 64 and a plurality of driven protrusions 72 formed on the second speed driving gear 49. When the first shifter 64 is positioned at the axial reference position on the spline 65, the trajectory of the driving protrusion 71 is separated from the trajectory of the driven protrusion 72. At this time, relative rotation between the first shifter 64 and the second speed drive gear 49 is allowed around the axis of the input shaft 41. When the first shifter 64 is displaced from the axial reference position toward the second speed drive gear 49 by the second distance and moved to the second operation position, the drive protrusion 71 is adjacent on the second speed drive gear 49 in the circumferential direction. It enters between the driven protrusions 72. The driving protrusion 71 is in surface contact with the driven protrusion 72 in the rotation direction of the input shaft 41. The driving protrusion 71 and the driven protrusion 72 each have a contact surface that extends in a virtual plane including the axis of the input shaft 41. Thus, the driving protrusion 71 and the driven protrusion 72 mesh with each other around the axis of the input shaft 41. When engaged, the second-speed drive gear 49 is coupled to the input shaft 41 through the first shifter 64 so as not to be relatively rotatable.

  The low driven gear 51 is supported by the output shaft 42 so as to be relatively rotatable and not axially displaceable. The low driven gear 51 meshes with the low driving gear 46 on the input shaft 41. The 4-speed driven gear 52 is integrated with the second shifter 73. The second shifter 73 is fitted into a spline 74 carved in the output shaft 42 and is supported on the spline 74 so as not to be relatively rotatable and to be axially displaceable. The third-speed driven gear 53 is supported by the output shaft 42 so as to be rotatable relative to the output shaft 42 but not axially displaceable. The second-speed driven gear 54 is fitted into a spline carved in the output shaft 42 and is supported on the spline so as not to be relatively rotatable and to be axially displaceable. The second speed driven gear 54 meshes with the second speed drive gear 49 on the input shaft 41.

  A third fitting mechanism 75 is configured between the low driven gear 51 and the fourth speed driven gear 52. The third fitting mechanism 75 includes a plurality of driving protrusions 76 formed on the second shifter 73 and a plurality of driven protrusions 77 formed on the low driven gear 51. When the second shifter 73 is positioned at the axial reference position on the spline 74, the trajectory of the driving projection 76 is separated from the trajectory of the driven projection 77. At this time, relative rotation between the second shifter 73 and the low driven gear 51 is allowed around the axis of the output shaft 42. When the second shifter 73 is displaced from the axial reference position toward the low driven gear 51 by the third distance and moved to the third operating position, the drive protrusion 76 is adjacent to the circumferential direction on the low driven gear 51. It enters between the driven protrusions 77. The driving protrusion 76 is in surface contact with the driven protrusion 77 in the rotation direction of the output shaft 42. Each of the driving protrusion 76 and the driven protrusion 77 is partitioned with a contact surface that extends in a virtual plane including the axis of the output shaft 42. Thus, the driving protrusion 76 and the driven protrusion 77 mesh with each other around the axis of the output shaft 42. At the time of meshing, the low driven gear 51 is coupled to the output shaft 42 through the second shifter 73 so as not to be relatively rotatable.

  A fourth fitting mechanism 78 is configured between the 4-speed driven gear 52 and the 3-speed driven gear 53. The fourth fitting mechanism 78 includes a plurality of driving protrusions 78 formed on the second shifter 73 and a plurality of driven protrusions 79 formed on the third speed driven gear 53. When the second shifter 73 is positioned at the axial reference position on the spline 74, the trajectory of the driving projection 78 is separated from the trajectory of the driven projection 79. At this time, relative rotation between the second shifter 73 and the third-speed driven gear 53 is allowed around the axis of the output shaft 42. When the second shifter 73 is displaced from the axial reference position toward the third-speed driven gear 53 by the fourth distance and moved to the fourth operating position, the drive protrusion 78 is circumferentially moved on the third-speed driven gear 53. It enters between adjacent driven protrusions 79. The driving protrusion 78 is in surface contact with the driven protrusion 79 in the rotation direction of the output shaft 42. The driving protrusion 78 and the driven protrusion 79 each have a contact surface that extends in a virtual plane including the axis of the output shaft 42. Thus, the driving protrusion 78 and the driven protrusion 79 mesh with each other around the axis of the output shaft 42. At the time of meshing, the third speed driven gear 53 is coupled to the output shaft 42 through the second shifter 73 so as not to be relatively rotatable.

  In the embodiment, the first engagement portion is formed on the side surface of the active gear 51 and is a plurality of engagement holes (or recesses) 77 arranged in the circumferential direction, and the second engagement portion is an engagement configured on the driven gear 52. The same number of engagement protrusions 76 as the holes 77 are formed. Between each engagement hole 77, the 1st engagement part extended in the radial direction of the active gear 51 is comprised, and the 2nd engagement part, ie, the engagement protrusion 76, and the 2nd engagement part contact | abut in the circumferential direction. To transmit power. However, as described above, in the present embodiment, when the engagement protrusion 76 does not engage with the engagement hole 77, the engagement protrusion 76 may contact the first engagement portion in the axial direction and the axial movement may be prevented. is there. The active gear 51 may be provided with an engagement protrusion, and the driven gear 52 may be provided with an engagement hole. The same applies to the configuration of the transmission gear, which will be described later, and it is described as a protrusion for convenience.

  When the first shifter 64, that is, the third speed drive gear 48 is positioned at the axial reference position on the input shaft 41, and the second shifter 73, that is, the fourth speed driven gear 52 is positioned at the axial reference position on the output shaft 42, the input The 4-speed drive gear 47 on the shaft 41 meshes with the 4-speed driven gear 52 on the output shaft 42, and the 3-speed drive gear 48 on the input shaft 41 meshes with the 3-speed driven gear 53 on the output shaft 42. The 4-speed drive gear 47 and the 2-speed drive gear 49 rotate relative to the input shaft 41. The low driven gear 51 and the third speed driven gear 53 rotate relative to the output shaft 42. In this state, no rotational force is transmitted from the input shaft 41 to the output shaft 42. In the multi-stage transmission 39, a neutral state is established.

  When the second shifter 73, that is, the fourth speed driven gear 52 moves from the axial reference position to the third operating position on the output shaft 42 from the neutral state, the driving protrusion 76 of the second shifter 73 is moved by the third fitting mechanism 75. It meshes with the driven projection 77 of the low driven gear 51. The low driven gear 51 is coupled to the output shaft 42. At this time, the 4-speed driven gear 52 is disengaged from the 4-speed drive gear 47 of the input shaft 41 as the second shifter 73 moves. The meshing between the 4-speed drive gear 47 and the 4-speed driven gear 52 is eliminated. The rotational force of the input shaft 41 transmitted to the low driven gear 51 drives the output shaft 42. Thus, the first speed is established in the multi-stage transmission 39.

  When the first shifter 64, that is, the third speed drive gear 48 moves from the axial reference position to the second operation position on the input shaft 41 from the neutral state, the drive protrusion 71 of the first shifter 64 is set to 2 by the second fitting mechanism 69. It meshes with the driven projection 72 of the fast drive gear 49. The second speed drive gear 49 is coupled to the input shaft 41. At this time, the third speed drive gear 48 is disengaged from the third speed driven gear 53 of the output shaft 42 with the movement of the first shifter 64. The meshing of the third speed driving gear 48 and the third speed driven gear 53 is eliminated. The rotational force of the input shaft 41 is transmitted to the second speed drive gear 49. Since the second speed drive gear 49 of the input shaft 41 meshes with the second speed driven gear 54 of the output shaft 42, the rotational force of the input shaft 41 drives the output shaft 42. Thus, the second speed is established in the multi-stage transmission 39.

  When the second shifter 73, that is, the fourth speed driven gear 52 moves from the axial reference position to the fourth operating position on the output shaft 41 from the neutral state, the driving protrusion 78 of the second shifter 73 is moved by the fourth fitting mechanism 78. It meshes with the driven projection 79 of the third speed driven gear 53. The third speed driven gear 53 is coupled to the output shaft 42. At this time, the 4-speed driven gear 52 is disengaged from the 4-speed drive gear 47 of the input shaft 41 as the second shifter 73 moves. The meshing between the 4-speed drive gear 47 and the 4-speed driven gear 52 is eliminated. The rotational force of the input shaft 41 transmitted to the third speed driven gear 53 drives the output shaft 42. In this manner, the third speed is established in the multi-stage transmission 39.

  When the first shifter 64, that is, the third speed drive gear 48 moves from the axial reference position to the first operating position on the input shaft 41 from the neutral state, the drive protrusion 67 of the first shifter 64 is 4 by the first fitting mechanism 66. It meshes with the driven projection 68 of the fast drive gear 47. The fourth speed drive gear 47 is coupled to the input shaft 41. At this time, the third speed drive gear 48 is disengaged from the third speed driven gear 53 of the output shaft 42 as the first shifter 64 moves. The meshing of the third speed driving gear 48 and the third speed driven gear 53 is eliminated. The rotational force of the input shaft 41 is transmitted to the fourth speed drive gear 47. Since the 4-speed drive gear 47 of the input shaft 41 meshes with the 4-speed driven gear 52 of the output shaft 42, the rotational force of the input shaft 41 drives the output shaft 42. Thus, the fourth speed is established in the multi-stage transmission 39.

  As shown in FIG. 4, a shift mechanism 81 is incorporated in the multi-stage transmission 39. The shift mechanism 81 includes a fork shaft 82 that extends parallel to the axis of the input shaft 41. A shift fork 83 is supported on the fork shaft 82 so as to be displaceable in the axial direction. The shift fork 83 extends in a direction perpendicular to the axial center of the fork shaft 82 and is connected to the first shifter 64 on the input shaft 41.

  The shift mechanism 81 includes a shift drum 84. The shift drum 84 is supported so as to be rotatable about an axis 85 extending parallel to the axis of the fork shaft 82. The shift drum 84 includes a first shift drum 84a that operates a transmission gear configured by a combination of the drive gears 46, 47, 48, and 49 and the driven gears 51, 52, 53, and 54, and an end of the first shift drum 84a. And a second shift drum 84b engaged with the portion. A shaft body 87 that is slidably supported by a slide bearing 86 formed in the second half 26b of the crankcase 26 is defined at the end of the first shift drum 84a. The second shift drum 84 b is coaxially stacked on the end surface of the shaft body 87 and fastened to the shaft body 87 with a screw 88. A detent pin 89 that crosses the boundary surface between the end face of the shaft body 87 and the second shift drum 84b is inserted. The anti-rotation pin 89 prevents relative rotation between the first shift drum 84a and the second shift drum 84b around the axis 85. In this manner, the crankcase 26 that supports the shift drum 84 is disposed between the first shift drum 84a and the second shift drum 84b. The diameter of the shaft body 87 and the sliding bearing 86 is made smaller than the reference surface of the first shift drum 84a and the reference surface of the second shift drum 84b. it can.

  A first cam groove 91 is formed on the outer peripheral surface of the first shift drum 84a. The first cam groove 91 is displaced in the direction of the axis 85 of the shift drum 84 according to the rotation angle. A pin 92 protruding from the shift fork 83 in a direction orthogonal to the axial center of the fork shaft 82 is inserted into the first cam groove 91. Thus, the shift fork 83 moves along the fork shaft 82 according to the rotation of the shift drum 84. The movement of the shift fork 83 causes the movement of the first shifter 64 on the input shaft 41. Thus, the first shift drum 84 a is connected to the first shifter 64, and generates a displacement of the first shifter 64 in the axial direction of the input shaft 41. A similar shift mechanism is also associated with the second shifter 73 on the output shaft 42.

  A second cam groove 93 is cut in the outer peripheral surface of the second shift drum 84b. The second cam groove 93 is displaced away from the first shift drum 84a in the direction of the axis 85 of the shift drum 84 corresponding to the rotational angle position when the neutral state of the first cam groove 91 is established.

  The clutch outer 56 includes a clutch gear 94 that holds the driven gear 45 b described above on the outer periphery, and a holding member 95 that is supported by the clutch gear 94 so that the relative angle can be changed around the axis of the input shaft 41. The clutch gear 94 is supported by the clutch hub 57 so as to be relatively rotatable about the axis of the input shaft 41 of the multi-stage transmission 39. The clutch gear 94 meshes with the drive gear 45a on the crankshaft 31. The drive gear 45a is coupled to the crankshaft 31 protruding from the second case half 26b of the crankcase 26 so as not to be relatively rotatable. Thus, the rotation of the crankshaft 31 is transmitted to the clutch gear 94 at a specified reduction ratio.

  The holding member 95 holds a plurality of friction plates 96. The friction plate 96 is supported by the holding member 95 so as to be displaceable in the axial direction of the input shaft 41. The friction plate 96 rotates with the holding member 95. Between the holding member 95 and the clutch gear 94, a coiled spring 97 and a damper 98 that absorb an impact in the circumferential direction are arranged. The power of the crankshaft 31 is transmitted to the holding member 95 around the axis of the input shaft 41 via the clutch gear 94.

  The clutch hub 57 is supported by the input shaft 41 so as not to be relatively rotatable. The clutch hub 57 includes a guide tube 99 that is mounted on the input shaft 41 so as not to rotate relative to the input shaft 41, and a holding member 102 that is pressed against the guide tube 99 from the axial direction via a washer 101. The clutch gear 94 is supported by the guide cylinder 99 so as to be relatively rotatable. The outer periphery of the holding member 102 is surrounded by the holding member 95 of the clutch outer 56. The holding member 102 holds a plurality of clutch plates 103. The clutch plate 103 is supported by the holding member 102 so as to be relatively displaceable in the axial direction of the input shaft 41. The clutch plate 103 is sandwiched between the friction plates 96.

  The friction clutch 55 includes a pressure plate 104 and a clutch lifter 105. The pressure plate 104 is attached to the clutch hub 57 so as to be displaceable in the axial direction of the input shaft 41. The pressure plate 107 sandwiches the friction plate 96 and the clutch plate 103 between the flange 57 a of the clutch hub 57. The lifter plate 106 of the clutch lifter 105 is fastened to the pressure plate 104. A clutch spring 107 is sandwiched between the lifter plate 106 and the clutch hub 57. The clutch spring 107 exerts an elastic force that presses the pressure plate 104 against the flange 57 a of the clutch hub 57. The friction plate 96 and the clutch plate 103 are frictionally joined by the action of the clutch spring 107. The clutch outer 56 is coupled to the clutch hub 57 based on such friction joining.

  A lifter rod 108 is connected to the lifter plate 106. The relative rotation of the lifter plate 106 around the axis of the input shaft 41 with respect to the lifter rod 108 is ensured. When the lifter rod 108 is pushed against the elastic force of the clutch spring 107 in conjunction with the operation of the clutch lever 23, the adhesion between the friction plate 96 and the clutch plate 103 is eliminated. The friction clutch 55 is disconnected.

  A sliding member 109 is attached to the guide cylinder 99 of the clutch hub 57. The sliding member 109 engages with the clutch hub 57 so as not to rotate relative to the input shaft 41. The sliding member 109 is supported by the guide tube 99 so as to be axially displaceable between a first position furthest away from the clutch gear 94 and a second position contacting the clutch gear 94 on the surface.

  The sliding member 109 surrounds the guide cylinder 99 and is engaged with the guide cylinder 99 around the axis of the input shaft 41 so as not to be relatively rotatable. A cylindrical body 112 that accommodates the boss 94a and a flange body 113 that extends radially outward from the cylindrical body 112 are partitioned. The annular body 111 is defined with a contact surface 114 that faces the boss 94 a of the clutch gear 94 and contacts the end surface of the boss 94 a at the second position of the sliding member 109. Here, the contact surface 114 and the end surface of the boss 94 a are orthogonal to the axis of the input shaft 41.

  A return spring 115 is disposed on the guide cylinder 99 of the clutch hub 57. The return spring 115 is constituted by a disc spring surrounding the guide cylinder 99, for example. The return spring 115 is sandwiched between the guide tube 99 and the sliding member 109 and applies an urging force to the sliding member 109 in a direction away from the clutch outer 56. Thus, the return spring 115 serves to maintain the sliding member 109 in the first position.

  An arm member 116 is attached to the sliding member 109 so as to be rotatable relative to the sliding member 109 around the axis of the input shaft 41. The arm member 116 is received by the flange body 113 of the sliding member 109 in the axial direction of the input shaft 41 and extends along the outer periphery of the cylindrical body 112. The arm member 116 has a cylindrical body 116a that is supported by the fork shaft 82 so as to be relatively rotatable. The cylindrical body 116a is supported by the fork shaft 82 so as to be capable of relative displacement in the axial direction. The fork shaft 82 penetrates through the second case half 26b of the crankcase 26 and supports the arm member 116 on the second shift drum 84b side of the crankcase 26 in the left-right direction.

  The arm member 116 has a pin 117 that is fixed to the cylindrical body 116a and extends in a direction perpendicular to the axial center of the fork shaft 82 and enters the second cam groove 93 of the second shift drum 84b. The movement of the pin 117 is guided by the second cam groove 93 during the rotation of the second shift drum 84b. When the second shift drum 84 b rotates about the axis 85, the arm member 116 is displaced in the axial direction of the fork shaft 82 based on the cam profile of the second cam groove 93.

  An elastic member 118 is attached to the sliding member 109. The elastic member 118 is constituted by a disc spring surrounding the cylindrical body 112 of the sliding member 109, for example. The arm member 116 is sandwiched between the flange body 113 and the elastic member 118 of the sliding member 109. The arm member 116 is pressed against the flange body 113 on the sliding member 109 by the action of the elastic member 118. When the arm member 116 is displaced away from the second case half 26b of the crankcase 26 based on the cam profile of the second cam groove 93, the sliding member 109 is moved from the first position to the second position via the elastic member 118. A propulsive force acts on the sliding member 109, and the contact surface 114 of the sliding member 109 contacts the boss 94 a (clutch outer 56) of the clutch gear 94.

  As shown in FIG. 5 (a), the arm member 116 is formed in a semi-annular shape following the outer periphery of the cylindrical body 112. The arm member 116 is in contact with the outer periphery of the cylindrical body 112 with an arc surface. In addition, as shown in FIG. 5B, the arm member 116 may be formed in an annular shape surrounding the outer periphery of the cylindrical body 112 without interruption. The arm member 116 is in contact with the outer periphery of the cylindrical body 112 on the inner cylindrical surface.

  During traveling, the friction plate 55 and the clutch plate 103 are frictionally joined in the friction clutch 55. The clutch hub 57 is connected to the clutch outer 56. In the multi-stage transmission 39, one of the first speed, the second speed, the third speed, and the fourth speed is established. The power of the crankshaft 31 is transmitted to the rear wheel WR at a reduction ratio determined through the friction clutch 55 and the multi-stage transmission 39.

  If the neutral state is established in the multi-stage transmission 39 during the stop, the driver can release the clutch lever 23 and connect the friction clutch 55. Prior to the connection of the friction clutch 55, the driver disconnects the friction clutch 55 once and establishes the neutral state with the multi-stage transmission 39. When the driver releases the clutch lever 23 again, the friction clutch 55 shifts to the connected state again, and the control circuit detects the neutral state of the multi-stage transmission 39 and the reconnection of the friction clutch 55. The control circuit performs idle stop at the engine 25. For example, a signal is supplied from the control circuit to the throttle valve, and the combustion operation of the engine 25 is stopped. The rotation of the crankshaft 31 stops. At this time, since no driving force is input to the input shaft 41 of the multi-stage transmission 39, the rotation of the drive gears 46 to 49 stops. At the time of idling stop, since the motorcycle 11 is in a stationary state, no driving force is input to the output shaft 42 of the multi-stage transmission 39. The rotation of the driven gears 51 to 54 is also stopped.

  Prior to resumption of traveling, the driver establishes, for example, the first speed with the multi-stage transmission 39 based on the shift operation. Prior to the shift operation, the driver operates the clutch lever 23. When the friction welding is released again and the friction clutch 55 is disconnected, the control circuit supplies a command signal to the ACG starter 58. The ACG starter 58 receives the command signal and drives the crankshaft 31. The clutch outer 56 is rotated by the action of the primary reduction mechanism 45.

  At this time, when the first shift drum 84a is in the neutral state, the arm member 116 drives the sliding member 109 and causes the sliding member 109 to abut the clutch outer 56 in accordance with the operation of the second shift drum 84b. The arm member 116 presses the sliding member 109 against the clutch outer 56 in the axial direction according to the cam profile defined by the second shift drum 84b. Thereby, a part of power is transmitted from the clutch outer 56 to the clutch hub 57, and it is possible to create a situation in which revolving between the clutch outer 56 and the clutch hub 57 is likely to occur. The low drive gear 46 rotates, and the low driven gear 51 (active gear) that meshes with the low drive gear 46 rotates. Since the output shaft 42 is stationary, relative rotation is caused between the second shifter 64 having a driven gear and the low driven gear 51. When the second shifter 73 (driven gear) moves from the axial reference position to the third operating position, the driven protrusion (first engaging protrusion) 77 of the low driven gear 51 is driven by the second shifter 73. Even when the second shifter 73 is prevented from moving in the axial direction by hitting the portion (second engagement protrusion) 76, the driven protrusion (first engagement protrusion) 77 of the low driven gear 51 becomes the second shifter by relative rotation. It is possible to enter the space adjacent to the 73 drive protrusions (second engagement protrusions) 76. In this way, a coupling state can be smoothly established between the drive protrusion (second engagement protrusion) 76 and the driven protrusion (first engagement protrusion) 77.

  In the present embodiment, when the first shift drum 84a is moved to a specific position around the rotation axis 85, the drive protrusions 67 and 71 of the first shifter 64 are driven by the driven protrusion 68 and the second speed drive of the fourth speed drive gear 47. The drive projections 76 and 78 of the second shifter 73 are separated from the driven projection 72 of the gear 49, respectively, and the driven projection 77 of the low driven gear 51 and the driven projection 79 of the third speed driven gear 53. Each will leave. A neutral state is established in the transmission gear that is changed by a combination of the driving protrusions 67, 71, 76, 78 and the driven protrusions 68, 72, 77, 79. When the first shift drum 84a is in such a neutral position, the first shifter 64 and the second shifter 73 having so-called active gears are driven gears (fourth speed drive gear 47, second speed drive gear 49, low driven gear 51 and The clutch hub 57 and the first and second shifters 64 and 73 are not engaged with the third-speed driven gear 53) and the friction plate 96 and the clutch plate 103 are disconnected in that state. Will not engage with the power source or output destination. Even in such a case, according to the present structure, a part of the power can be transmitted to the clutch hub 57, and the arm member 116 and the sliding member 109 according to the operation of the first shift drum 84a to a specific position. The operation with can be canceled.

  The shift drum 84 is divided into a first shift drum 84a and a second shift drum 84b. The first shift drum 84a operates a transmission gear that is changed by a combination of the driving protrusions 67, 71, 76, 78 and the driven protrusions 68, 72, 77, 79. A second cam groove 93 that drives the arm member 116 is formed in the second shift drum 84b. A second case half 26b of the crankcase 26 is disposed between the first shift drum 84a and the second shift drum 84b. Since the first shift drum 84a is supported at both ends, the operation of the first shift drum 84a is stabilized. The shift drum 84 is firmly supported. Further, the first shift drum 84a is disposed inside the crankcase 26, and the friction clutch 55 is disposed outside the crankcase 26, that is, on the other side where the first shift drum 84a is disposed. By arranging the second shift drum 84b on the outer side, that is, on the same side as the friction clutch 55, the structure of the arm member 116 can be simplified, and the structure of the crankcase 26 can also be simplified. Can do.

  A shift fork 83 for operating the transmission gear is engaged with the first shift drum 84a. A fork shaft 82 that supports the shift fork 83 is disposed in the crankcase 26. The fork shaft 82 penetrates the crankcase 26 and supports the arm member 116 outside the crankcase 26. The fork shaft 82 is shared by the shift fork 83 and the arm member 116. In arranging the arm member 116, an increase in the number of parts is suppressed. Since the shift fork 82 is firmly supported by the crankcase 26, the operation of the arm member 116 is stabilized.

  In the present embodiment, an elastic member 118 is disposed on the sliding member 109, and the arm member 116 is sandwiched between the elastic member 118 and the sliding member 109. When the sliding member 109 is maintained at the second position, the pressing force of the arm member 116 is not directly transmitted to the sliding member 109 but is transmitted via the elastic member 118. Thus, the frictional load on the arm member 116 can be reduced.

A return spring 115 is attached to the guide cylinder 99 of the clutch hub 57. The return spring 115 imparts an elastic force to the sliding member 109 in a direction away from the clutch outer 56. The return spring 115 holds the sliding member 109 in the first position. At this time, the action of the return spring 115 can reduce the contact between the sliding member 109 and the clutch outer 56 due to vehicle body vibration or the like.

  25 ... Engine, 26 ... Crankcase, 26b ... Second case half, 31 ... Crankshaft, 39 ... Power transmission device (multi-stage transmission), 41 ... Second shaft (input shaft), 42 ... First shaft (output) Shaft), 51 ... Active gear (low driven gear), 52 ... Driven gear (4-speed driven gear), 56 ... Clutch outer, 57 ... Clutch hub, 58 ... Starter motor (ACG starter), 76 ... Second engagement Joint protrusion (drive protrusion), 77... First engagement protrusion (driven protrusion), 82. Fork shaft, 83. Shift fork, 84. Shift drum, 84 a. First shift drum, 84 b. 91 ... Cam groove (first cam groove), 93 ... Cam groove (second cam groove), 96 ... Friction plate, 103 ... Clutch plate, 109 ... Sliding member, 114 ... Contact surface, 115 ... Return spring , 116 ... arm member, 118 ... elastic member.

Claims (7)

A clutch outer (56) connected to the power input side and holding the friction plate (96);
A clutch hub (57) that holds a clutch plate (103) that is rotatably supported relative to the clutch outer (56) and that can be frictionally joined to the friction plate (96);
An active gear (51) coupled to the clutch hub (57) and having a first engagement portion (77);
A second engagement portion (which is supported coaxially by the active gear (51) so as to be displaceable in the axial direction and engages with the first engagement portion (77) when moved from the axial reference position to the operating position in the axial direction. 76) a driven gear (52) having
A plurality of transmission gears (46, 47, 51, 52) that are changed by a combination of the active gear (51) and the driven gear (52);
In the power transmission device (39) including a shift drum (84) for operating the transmission gear (46, 47, 51, 52),
A plurality of cam grooves (91, 93) are formed in the shift drum (84),
A sliding member (109) having a contact surface (114) that contacts the clutch outer (56) engages with the clutch hub (57),
An arm member (116) for driving the sliding member (109) is connected to the cam groove (93),
The arm member (116) causes the sliding member (109) to contact the clutch outer (56) by driving the sliding member (109) in accordance with the operation of the shift drum (84). A power transmission device characterized by that.   The power transmission device according to claim 1, wherein the arm member (116) is in a neutral position where the shift drum (84) is not engaged with the active gear (51) and the driven gear (52). The power transmission device is operated by the cam groove (93) formed in the shift drum (84).   The power transmission device according to claim 1 or 2, wherein the shift drum (84) includes a first shift drum (84a) for operating the transmission gear (46, 47, 51, 52), and the first shift drum. A cam groove (93) that includes a second shift drum (84b) engaged with an end of (84a), and moves the arm member (116) to the second shift drum (84b). The power transmission device, wherein a crankcase (26) that supports the shift drum (84) is disposed between the first shift drum (84a) and the second shift drum (84b).   The power transmission device according to claim 3, wherein a shift fork (83) for operating a transmission gear (46, 47, 51, 52) is engaged with the first shift drum (84a), and the shift fork (83 ) Is disposed in the crankcase (26), and the fork shaft (82) penetrates the crankcase (26) and the first of the crankcase (26) in the left-right direction. The power transmission device, wherein the arm member (116) is supported on the two shift drum (84b) side.   The power transmission device according to any one of claims 1 to 4, wherein an elastic member (118) is disposed on the sliding member (109), and the arm member (116) is connected to the elastic member (118). A power transmission device, wherein the power transmission device is sandwiched between the sliding member (109).   The power transmission device according to claim 5, wherein a return spring (115) is disposed on the clutch hub (57), and the return spring (115) is connected to the sliding member (109) and the clutch outer (56). A power transmission device characterized by applying an urging force in a direction away from the power supply. The power transmission device according to claim 2,
A first shaft (42) for supporting a drive gear or driven gear (51, 52, 53, 54) including the active gear (51) and the driven gear (52), and the driving gear or the driven gear A multi-stage transmission including a second shaft (41) that supports a driven gear or a drive gear (46, 47, 48, 49) that can mesh with the first shaft (42) and the second shaft (41). When the neutral state that cuts off the transmission of power between the friction plate (96) and the clutch plate (103) is established, control for stopping the combustion operation of the engine (25) is established. Circuit,
A starter motor connected to the crankshaft (31) of the engine (25) and automatically starting the crankshaft (31) in response to a command signal from the control circuit when the frictional connection is released again in the neutral state. (58). The power transmission device characterized by the above-mentioned.

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