Transmission system

Abstract

To provide a transmission system capable of manually and automatically engaging / disengaging a clutch device.SOLUTION: A transmission system includes a clutch device (26), a clutch actuator (50), and a release mechanism (38). The release mechanism (38) includes a release shaft (53) for transmitting driving force of the clutch actuator (50) to the clutch device (26) side. The release shaft (53) is constituted by arranging a first release shaft (61), a second release shaft (62), and a third release shaft (63) linearly. The first release shaft (61) is rotated by input through manual operation of an occupant, and the rotation can rotate the third release shaft (63) independently of rotation of the second release shaft (62) by using the clutch actuator (50).SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present invention relates to a transmission system. This application claims priority based on Japanese Patent Application No. 2021-062193 filed in Japan on March 31, 2021, and incorporates its content herein by reference.

Background Art

[0002] In recent years, in saddle-riding type vehicles, an automatic clutch system has been proposed in which the disengagement and engagement operations of a clutch device are automatically performed by electric control (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present invention provides a transmission system capable of manually and automatically disengaging and engaging a clutch device.

Means for Solving the Problems

[0005] As a means for solving the above problems, one aspect of the present invention includes a clutch device (26) for disconnecting and connecting power transmission, a clutch actuator (50) for outputting a driving force for operating the clutch device (26), and a release mechanism (38) for operating the clutch device (26) by receiving the driving force of the clutch actuator (50). In a transmission system in which the release mechanism (38) includes a release shaft (53) for transmitting the driving force of the clutch actuator (50) to the clutch device (26) side, the release shaft (53) includes a first release shaft (61) that rotates by a manual operation of an occupant, a second release shaft (62) that is rotatable by the clutch actuator (50), and a third release shaft (63) that is rotated by the rotation of the first release shaft (61) and the second release shaft (62) and operates the clutch device (26). The first release shaft (61) is rotated by an input by a manual operation of an occupant, and the rotation can rotate the third release shaft (63) independently of the rotation of the second release shaft (62) by the clutch actuator (50).

[0006] In the above aspect, the clutch device (26) includes a cover (17a) that covers the clutch device (26) from the outside. The third release shaft (63) is rotatably supported by the cover (17a), and the first release shaft (61) and the second release shaft (62) may be rotatably supported by a gear case (59) disposed in the clutch actuator (50).

[0007] In the above aspect, the release mechanism (38) may dispose the first release shaft (61) at the upper part and the third release shaft (63) at the lower part, and the second release shaft (62) may be disposed between the first release shaft (61) and the third release shaft (63).

[0008] In the above aspect, the third release shaft (63) has a cylindrical shape, and an engaging portion between the lower end portion of the first release shaft (61) and the upper end portion of the second release shaft (62) can be inserted therethrough. Further, a driven gear (63a) is supported on the third release shaft (63) so as to be integrally rotatable, and a control operation side cam (63b) having a sector-shaped cross section and extending in the axial direction may be provided on the third release shaft (63).

[0009] In the above aspect, the coupling portion between the first release shaft (61) and the second release shaft (62) may be disposed inside the cylinder of the third release shaft (63).

[0010] In the above aspect, the third release shaft (63) has a cylindrical shape, and an engaging portion between the lower end portion of the first release shaft (61) and the upper end portion of the second release shaft (62) can be inserted therethrough. Further, a driven gear (63a) is supported on the third release shaft (63) so as to be integrally rotatable, and a control operation side cam (63b) having a sector-shaped cross section and extending in the axial direction may be provided on the third release shaft (63).

[0011] In the above aspect, the control operation side cam (63b) may be disposed so as to avoid the manual operation side cam (61b) of the first release shaft (61) in the axial direction or the radial direction.

Effect of the Invention

[0012] According to the present invention, it is possible to provide a transmission system capable of manually and automatically connecting and disconnecting a clutch device.

Brief Description of the Drawings

[0013]

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Mode for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, directions such as front, rear, left, and right are the same as those in the vehicle described below unless otherwise specified. Also, at appropriate positions in the drawings used in the following description, an arrow FR indicating the front of the vehicle, an arrow LH indicating the left side of the vehicle, and an arrow UP indicating the upper side of the vehicle are shown.

[0015] <Vehicle as a Whole> As shown in FIG. 1, this embodiment is applied to a motorcycle 1 as an example of a saddle-riding type vehicle. The front wheel 2 of the motorcycle 1 is supported at the lower ends of a pair of left and right front forks 3. The upper parts of the left and right front forks 3 are supported by a head pipe 6 at the front end of a vehicle body frame 5 via a steering stem 4. A bar-type steering handle 4a is attached on the top bridge of the steering stem 4.

[0016] The vehicle body frame 5 includes a head pipe 6, a main frame 7 extending downward and rearward from the head pipe 6 toward the center in the vehicle width direction (left - right direction), a pivot frame 8 provided below the rear end of the main frame 7, and a seat frame 9 connected to the rear of the main frame 7 and the pivot frame 8. The front end of a swing arm 11 is pivotally supported by the pivot frame 8 so as to be swingable. The rear wheel 12 of the motorcycle 1 is supported at the rear end of the swing arm 11.

[0017] A fuel tank 18 is supported above the left and right main frames 7. A front seat 19 and a rear seat 19a are supported above the seat frame 9 and behind the fuel tank 18. On both left and right sides of the rear part of the fuel tank 18, knee - grip portions 18a recessed inward in the vehicle width direction are formed. The left and right knee - grip portions 18a are formed to align with the following part: the inner sides around the left and right knees of the driver sitting on the front seat 19. Steps 18b are supported on both left and right sides below the front seat 19. The driver places the feet from the ankles forward on the steps 18b.

[0018] Below the main frame 7, a power unit PU including the engine of the motorcycle 1 is suspended. The power unit PU integrally has an engine (internal combustion engine, prime mover) 13 located on its front side and a transmission 21 located on its rear side. The engine 13 is, for example, a multi - cylinder engine with the rotation axis of a crankshaft 14 along the left - right direction (vehicle width direction).

[0019] The engine 13 has a cylinder 16 standing upright above the front part of a crankcase 15. The rear part of the crankcase 15 is a transmission case 17 that houses the transmission 21. On the right side part of the crankcase 15, a right cover 17a extending to the right side part of the transmission case 17 is attached. The right cover 17a is also a clutch cover that covers a clutch device 26. The power unit PU is linked to the rear wheel 12 via, for example, a chain - type transmission mechanism (not shown).

[0020] <Transmission> Referring also to FIG. 2, the transmission 21 is a stepped transmission. The transmission 21 has a main shaft 22, a countershaft 23, and a gearshift gear group 24 straddling both shafts 22 and 23. The countershaft 23 constitutes the output shaft of the transmission 21 and thus the power unit PU. The left end of the countershaft 23 protrudes to the left rear of the transmission case 17 and is connected to the rear wheel 12 via the chain drive mechanism.

[0021] The main shaft 22 and the countershaft 23 of the transmission 21 are arranged behind the crankshaft 14. A clutch device 26 is coaxially arranged at the right end of the main shaft 22. The clutch device 26 disconnects and connects the power transmission between the crankshaft 14 of the engine 13 and the main shaft 22 of the transmission 21. The clutch device 26 is disconnected and connected by at least one of an operation by an operator of a clutch operating element (for example, a clutch lever not shown) and an operation of a clutch actuator 50 described in detail later.

[0022] The clutch device 26 is, for example, a wet multi-plate clutch and is a so-called normal closed clutch. The rotational power of the crankshaft 14 is transmitted to the main shaft 22 via the clutch device 26 and then from the main shaft 22 to the countershaft 23 via an arbitrary gear pair of the gearshift gear group 24. A drive sprocket 27 of the chain drive mechanism is attached to the left end of the countershaft 23 protruding to the left rear of the crankcase 15.

[0023] In the vicinity of the transmission 21 within the transmission case 17, a change mechanism 25 for switching gear pairs of the transmission gear group 24 is accommodated. The change mechanism 25 has a hollow cylindrical shift drum 32 parallel to both shafts 22 and 23. By the rotation of this shift drum 32, the change mechanism 25 operates a plurality of shift forks 32a. This operation is performed according to the pattern of the lead grooves formed on the outer periphery of the shift drum 32. By this operation, the change mechanism 25 switches the gear pair used for power transmission between both shafts 22 and 23 in the transmission gear group 24.

[0024] Here, the motorcycle 1 has the driver perform only the shifting operation of the transmission 21 (foot operation of a shift pedal (not shown)), and the engagement / disengagement operation of the clutch device 26 is automatically performed by electric control according to the operation of the shift pedal. That is, the motorcycle 1 employs a so-called semi-automatic transmission system (automatic clutch type transmission system).

[0025] <Transmission system> As shown in FIG. 3, the above-described transmission system 30 includes a clutch actuator 50, a control unit 40, various sensors 41 to 46, 57d, 58d, and various devices 47, 48, 50. The control unit 40 controls the operation of the ignition device 47 and the fuel injection device 48, and also controls the operation of the clutch actuator 50. This control is based on the detection information from the acceleration sensor 41, the gear position sensor 42, and the shift load sensor 43 (for example, a torque sensor), as well as various vehicle state detection information such as the throttle opening sensor 44, the vehicle speed sensor 45, and the engine speed sensor 46. The acceleration sensor 41 detects the behavior of the vehicle body. The gear position sensor 42 detects the gear position from the rotation angle of the shift drum 32. The shift load sensor 43 detects the operating torque input to the shift spindle 31 (see FIG. 2) of the change mechanism 25. The throttle opening sensor 44 detects the throttle opening. The vehicle speed sensor 45 detects the vehicle speed. The engine speed sensor 46 detects the engine speed.

[0026] The control unit 40 includes a clutch control unit 40C and an engine control unit 40E that are independent of each other. The clutch control unit 40C mainly controls the drive of the clutch actuator 50. The engine control unit 40E mainly controls the drive of the engine 13. The clutch control unit 40C and the engine control unit 40E are configured as, for example, separate ECUs (Electronic Control Units). The clutch control unit 40C and the engine control unit 40E may be configured within an integrated ECU as long as they perform independent controls from each other.

[0027] Referring to FIGS. 5 and 6 together, the clutch actuator 50 controls the operating torque applied to the release shaft 53 in order to connect and disconnect the clutch device 26. The clutch actuator 50 includes an electric motor 52 (hereinafter simply referred to as the motor 52) as a drive source, and a speed reduction mechanism 51 that transmits the driving force of the motor 52 to the release shaft 53. The speed reduction mechanism 51 includes a first reduction shaft 57 and a second reduction shaft 58. A first rotation angle sensor 57d and a second rotation angle sensor 58d for detecting the rotation angle are provided on each of these shafts 57, 58.

[0028] The clutch control unit 40C calculates the following current values based on a preset arithmetic program. The current value is the value of the current supplied to the motor 52 in order to connect and disconnect the clutch device 26. The supply current to the motor 52 is obtained from the correlation with the torque output to the motor 52. The target torque of the motor 52 is proportional to the operating torque (the driven clutch lever torque described later) applied to the release shaft 53. The current value supplied to the motor 52 is detected by a current sensor 40b included in the clutch control unit 40C. The clutch actuator 50 is controlled to operate according to the change in this detected value. The clutch actuator 50 will be described in detail later.

[0029] <Clutch Device> As shown in FIGS. 2 and 11, the clutch device 26 of the embodiment is a multi-plate clutch in which a plurality of clutch plates 35 are stacked in the axial direction, and is a wet clutch disposed in an oil chamber within the right cover 17a. The clutch device 26 includes a clutch outer 33, a clutch center 34, and a plurality of clutch plates 35. Rotational power is constantly transmitted from the crankshaft 14 to drive the clutch outer 33. The clutch center 34 is disposed within the clutch outer 33 and is integrally rotatably supported by the main shaft 22. The plurality of clutch plates 35 are stacked between the clutch outer 33 and the clutch center 34 and frictionally engaged therewith.

[0030] A pressure plate 36 having substantially the same diameter as the clutch plates 35 is disposed on the right side (outer side in the vehicle width direction) of the stacked clutch plates 35. The pressure plate 36 is biased leftward by receiving the elastic load of the clutch spring 37, and presses (frictionally engages) the stacked clutch plates 35 against each other. Thereby, the clutch device 26 is in a connection state capable of power transmission. The clutch device 26 is a normally closed clutch that is in a connected state during normal times without external input.

[0031] The release of the pressing (frictional engagement) is achieved by the operation of a release mechanism 38 inside the right cover 17a. The operation of the release mechanism 38 is performed by at least one of an operation of a clutch lever (not shown) by the occupant and application of torque by the clutch actuator 50.

[0032] <Release mechanism> As shown in FIGS. 2 and 11, the release mechanism 38 includes a lifter shaft 39 and a release shaft 53. The lifter shaft 39 is held reciprocally movable in the axial direction within the right side portion of the main shaft 22. The release shaft 53 is disposed perpendicular to the axial direction of the lifter shaft 39 and is held rotatable about its axis at the outer side portion of the right cover 17a. In the figure, the line C3 indicates the central axis of the release shaft 53 that extends in the vertical direction. The release shaft 53 has its axial direction tilted backward such that, when viewed axially (from the side of the vehicle) of the main shaft 22, it is positioned more rearward on the upper side with respect to the vertical direction (see Fig. 1). The upper part of the release shaft 53 protrudes outside the right cover 17a, and a driven clutch lever 54 is integrally rotatably attached to the upper part of this release shaft 53. The driven clutch lever 54 is connected to the clutch lever via an operation cable (not shown).

[0033] At the lower part of the release shaft 53 located inside the right cover 17a, an eccentric cam portion 38a is provided. The eccentric cam portion 38a engages with the right end portion of the lifter shaft 39. By rotating around its axis, the release shaft 53 moves the lifter shaft 39 to the right due to the action of the eccentric cam portion 38a. The lifter shaft 39 is configured to be reciprocally movable integrally with the pressure plate 36 of the clutch device 26. Therefore, when the lifter shaft 39 moves to the right, the pressure plate 36 moves (lifts) to the right against the biasing force of the clutch spring 37. This releases the frictional engagement between the stacked clutch plates 35. As a result, the normally closed clutch device 26 enters a state where power transmission is impossible, i.e., a disengaged state.

[0034] Note that the release mechanism 38 is not limited to an eccentric cam mechanism and may be provided with a rack & pinion, a feed screw, or the like. The mechanism for connecting the clutch lever and the driven clutch lever 54 is not limited to an operation cable and may be provided with a rod, a link, or the like.

[0035] <Clutch Control Mode> As shown in FIG. 4, the clutch control device 40A of the present embodiment has three types of clutch control modes. The clutch control modes include an auto mode M1 for performing automatic control, a manual mode M2 for performing manual operation, and a manual intervention mode M3 for performing temporary manual operation. The clutch control mode appropriately transitions among the three modes according to the operation of a clutch control mode changeover switch 49 (see FIG. 3) and the operation of a clutch operator. Note that the target including the manual mode M2 and the manual intervention mode M3 is referred to as a manual system M2A.

[0036] The auto mode M1 is a mode in which, according to automatic start / shift control, a clutch capacity suitable for the running state is calculated to control the clutch device 26. The manual mode M2 is a mode in which, according to a clutch operation instruction from an occupant, a clutch capacity is calculated to control the clutch device 26. The manual intervention mode M3 is a mode in which, during the auto mode M1, a clutch operation instruction from an occupant is received, a clutch capacity is calculated from the clutch operation instruction, and the clutch device 26 is controlled, and it is a temporary manual operation mode. Note that during the manual intervention mode M3, for example, when a state where the occupant stops operating the clutch operator (fully released state) continues for a specified time, it may be set to return to the auto mode M1.

[0037] For example, when the system is started, the clutch control device 40A starts control from a clutch-on state (connected state) in the auto mode M1. Also, when the engine 13 stops (system off), the clutch control device 40A is set to return to clutch-on in the auto mode M1. In the normally closed clutch device 26, when the clutch is on, power supply to the motor 52 of the clutch actuator 50 is not required. On the other hand, power supply to the motor 52 is maintained in the clutch-off state (disconnected state) of the clutch device 26.

[0038] In the automatic mode M1, it is basic to automatically perform clutch control. The automatic mode M1 enables the motorcycle 1 to run with no lever operation. In the automatic mode M1, the clutch capacity is controlled based on the throttle opening, engine speed, vehicle speed, shift sensor output, etc. Thereby, the motorcycle 1 can start without stalling (meaning engine stop or engine stall) only by throttle operation. Also, the motorcycle 1 can be shifted only by shift operation. Further, in the automatic mode M1, when the occupant grips the clutch lever, it switches to the manual intervention mode M3. Thereby, the clutch device 26 can be arbitrarily disengaged.

[0039] On the other hand, in the manual mode M2, the clutch capacity can be controlled by the lever operation by the occupant (that is, the clutch device 26 can be connected and disconnected). The automatic mode M1 and the manual mode M2 can be switched mutually. This switching is made, for example, by operating the clutch control mode changeover switch 49 (see FIG. 3) while the motorcycle 1 is stopped and the transmission 21 is in neutral. Note that the clutch control device 40A may be provided with an indicator indicating that it is in the manual state when transitioning to the manual system M2A (manual mode M2 or manual intervention mode M3).

[0040] In the manual mode M2, it is basic to manually perform clutch control. The manual mode M2 can control the clutch capacity according to the operating angle of the clutch lever (and thus the operating angle of the driven clutch lever 54). Thereby, the connection and disconnection of the clutch device 26 can be controlled according to the intention of the occupant. Note that even in the manual mode M2, when a shift operation is performed without a clutch operation, clutch control can automatically intervene. Hereinafter, the operating angle of the driven clutch lever 54 is referred to as the driven clutch lever operating angle.

[0041] In the automatic mode M1, the clutch actuator 50 automatically engages and disengages the clutch device 26. At this time, by performing a manual clutch operation on the clutch lever, it is possible to temporarily intervene in the automatic control of the clutch device 26 with a manual operation (manual intervention mode M3).

[0042] <Manual clutch operation> In the motorcycle 1 shown in FIG. 1, a clutch lever (not shown) as a clutch manual operator is attached to the proximal end side (inner side in the vehicle width direction) of the left grip of the steering handle 4a. Referring also to FIG. 2, the clutch lever is connected to a driven clutch lever 54 attached to the release shaft 53 of the clutch device 26 via an operation cable (not shown). The driven clutch lever 54 is integrally rotatably attached to the upper end portion protruding above the right cover 17a on the release shaft 53.

[0043] Also, for example, a handle switch attached to the steering handle 4a is provided with the clutch control mode switching switch 49. Thereby, during normal driving, the rider can easily switch the clutch control mode.

[0044] <Clutch actuator> As shown in FIG. 1, a clutch actuator 50 is attached to the rear upper portion of the right cover 17a on the right side of the crankcase 15. Referring also to FIGS. 5 and 6, the clutch actuator 50 includes a motor 52 and a speed reduction mechanism 51. The motor 52 is, for example, a DC motor and is arranged, for example, parallel to the release shaft 53 in the axial direction. The motor 52 is arranged so that the drive shaft 55 protrudes upward. The speed reduction mechanism 51 transmits the driving force of the motor 52 to the release shaft 53.

[0045] In the embodiment, a single clutch actuator 50 is provided with a plurality (two) of motors 52. Hereinafter, the motor 52 located on the vehicle front side of the clutch actuator 50 is referred to as the first motor 521, and the motor 52 located on the vehicle rear side and inside the vehicle width direction with respect to the first motor 521 is referred to as the second motor 522. In the figure, the lines C01 and C02 indicate the central axes (drive axes) of the respective motors 521 and 522. For convenience of explanation, both motors 521 and 522 may be collectively referred to as the motor 52. Also, both axes C01 and C02 may be collectively referred to as the axis C0. The control of the plurality (two) of motors 52 will be described later.

[0046] The speed reduction mechanism 51 reduces the rotational power output from the motor 52 and transmits it to the release shaft 53. The speed reduction mechanism 51 includes, for example, a gear train parallel to the axial direction of the release shaft 53. The speed reduction mechanism 51 includes a drive gear 55a, a first reduction gear 57a, a first small-diameter gear 57b, a second reduction gear 58a, a second small-diameter gear 58b, a driven gear 63a, and a gear case 59. The drive gear 55a is integrally provided on the drive shaft 55 of each motor 521 and 522. The first reduction gear 57a meshes with each drive gear 55a. The first small-diameter gear 57b is provided coaxially with the first reduction gear 57a. The second reduction gear 58a meshes with the first small-diameter gear 57b. The second small-diameter gear 58b is provided coaxially with the second reduction gear 58a. The driven gear 63a meshes with the second small-diameter gear 58b. The gear case 59 houses each gear.

[0047] The first reduction gear 57a and the first small-diameter gear 57b are integrally rotatably supported by the first support shaft 57c. The first reduction gear 57a, the first small-diameter gear 57b, and the first support shaft 57c constitute the first reduction shaft 57. The second reduction gear 58a and the second small-diameter gear 58b are integrally rotatably supported by the second support shaft 58c. The second reduction gear 58a, the second small-diameter gear 58b, and the second support shaft 58c constitute the second reduction shaft 58. The first support shaft 57c and the second support shaft 58c are each rotatably supported by the gear case 59. The second reduction gear 58a is a sector gear centered on the second support shaft 58c. The second reduction gear 58a is provided so as to extend forward of the second support shaft 58c and outward in the vehicle width direction. In the figure, the line C1 indicates the central axis of the first reduction shaft 57, and the line C2 indicates the central axis of the second reduction shaft 58, respectively.

[0048] The driven gear 63a is integrally rotatably provided on the release shaft 53. The driven gear 63a is a sector gear centered on the release shaft 53. The driven gear 63a is provided so as to extend forward of the release shaft 53. The gears on the downstream side in the reduction mechanism 51 have a small rotation angle. Therefore, the second reduction gear 58a and the driven gear 63a can be sector gears with a small rotation angle.

[0049] As a result, the reduction mechanism 51 and thus the clutch actuator 50 can be downsized. That is, even when a large-diameter reduction gear is provided to obtain a reduction ratio, by cutting out the portion outside the meshing range of this reduction gear to form a sector shape, the following effects can be achieved. That is, it is possible to particularly suppress the protrusion of the reduction mechanism 51 outward in the vehicle width direction, and it is possible to reduce the weight of the reduction mechanism 51.

[0050] With such a configuration, the motor 52 and the release shaft 53 can be constantly interlocked via the reduction mechanism 51. Thereby, a system is configured to directly connect and disconnect the clutch device 26 with the clutch actuator 50.

[0051] Each gear is a flat spur gear with a reduced axial thickness, and the gear case 59 is also formed in a flat shape with a reduced axial thickness. As a result, the reduction mechanism 51 is less conspicuous when viewed from the side of the vehicle. On the upper surface side of the gear case 59, a first rotation angle sensor 57d and a second rotation angle sensor 58d are provided. The first rotation angle sensor 57d and the second rotation angle sensor 58d are connected to one end of each of the first reduction shaft 57 and the second reduction shaft 58 to detect their rotation angles.

[0052] The motor 52 is arranged so as to protrude downward from the front part of the gear case 59. As a result, the motor 52 can be arranged as follows. That is, it can be arranged avoiding the bulging part 17b that covers the clutch device 26 in the right cover 17a forward. For this reason, the protrusion of the clutch actuator 50 outward in the vehicle width direction is suppressed.

[0053] The driving force of the motor 52 is decelerated as follows and transmitted to the release shaft 53. That is, the driving force of the motor 52 is decelerated between the driving gear 55a and the first reduction gear 57a, and between the first small-diameter gear 57b and the second reduction gear 58a, and further decelerated between the second small-diameter gear 58b and the driven gear 63a.

[0054] In the embodiment, a stopper 59a is provided in front of the final stage of the gear train of the reduction mechanism 51 (between the second small-diameter gear 58b and the driven gear 63a). The stopper 59a defines the initial position of the release shaft 53 (the stop position in the return direction opposite to the clutch disengagement direction). The stopper 59a is integrally formed inside the gear case 59, for example. The stopper 59a defines the stop position of the second reduction gear 58a by abutting against the side of the fan-shaped second reduction gear 58a. By providing the stopper 59a at a stage where the torque is smaller than that of the final stage of the reduction mechanism 51, the following effects can be obtained. That is, while suppressing the strength of the gear case 59, the initial position of the release shaft 53 can be reliably defined. In addition, it is possible to prevent excessive load input to the final stage where the torque becomes the largest due to deceleration, and the gears can be made smaller and lighter.

[0055] <Arrangement of Clutch Actuator> As shown in FIGS. 15 to 17, the clutch actuator 50 is arranged vertically below the kneegrip portion 18a on the right side of the fuel tank 18 in a side view of the vehicle. The clutch actuator 50 is arranged to project outward in the vehicle width direction from the kneegrip portion 18a on the right side of the fuel tank 18 in a top view of the vehicle shown in FIG. 16. The center line L1 in the figure imagines the thigh portion of the driver's leg, the center line L2 imagines the lower leg portion below the knee, and the center line L3 imagines the foot portion beyond the ankle, respectively.

[0056] In a side view of the vehicle, the driver's leg extends the lower leg portion L2 obliquely rearward and downward from the kneegrip portion 18a and places the foot portion L3 on the step 18b. The clutch actuator 50 projects outward in the vehicle width direction from the kneegrip portion 18a. The clutch actuator 50 is arranged to avoid the lower leg portion L2 of the driver's leg forward in a side view of the vehicle. Thereby, the interference of the clutch actuator 50 with the arrangement space of the driver's leg is suppressed. Even when the driver extends the leg and lands the foot portion L3, the clutch actuator 50 is arranged to avoid the lower leg portion L2 of the driver's leg forward in a side view of the vehicle. Also in this respect, the interference of the clutch actuator 50 with the arrangement space of the driver's leg is suppressed.

[0057] Referring to FIG. 17, the right cover 17a has the following range as a bulging portion 17b bulging outward in the vehicle width direction. The said range is a circular range coaxial with the clutch device 26 in a side view of the vehicle. A cover recess 17c is formed at a portion facing rearward and upward in the bulging portion 17b. The cover recess 17c changes the outer surface inward in the vehicle width direction with respect to the remaining portion. The cover recess 17c has a semi-circular shape in a side view of the vehicle.

[0058] The semicircular chord portion of the cover recess 17c is formed in a straight line perpendicular to the axial direction of the release shaft 53 when viewed from the side of the vehicle. This chord portion forms a stepped portion 17d that changes the outer surface of the bulging portion 17b in a stepped manner. The stepped portion 17d is inclined downward to the rear when viewed from the side of the vehicle. The upper part of the release shaft 53 protrudes obliquely upward and rearward from the stepped portion 17d of the cover recess 17c. The release shaft 53 penetrates the stepped portion 17d of the cover recess 17c and protrudes outside the cover. The clutch actuator 50 is attached to the right cover 17a in a state of being arranged so as to enter the cover recess 17c.

[0059] <Release shaft> As shown in FIGS. 6 to 8, the release shaft 53 is divided into a plurality of elements in order to be rotatable by receiving inputs from the clutch actuator 50 and inputs by the operation of the occupant separately. The release shaft 53 includes an upper release shaft 61 that constitutes the upper part, a lower release shaft 62 that constitutes the lower part, and an intermediate release shaft 63. The intermediate release shaft 63 is arranged across the lower end of the upper release shaft 61 and the upper end of the lower release shaft 62.

[0060] The upper release shaft 61 has a cylindrical shape. The upper release shaft 61 is rotatably supported by the upper boss portion 59b of the gear case 59. The upper end of the upper release shaft 61 protrudes outside the gear case 59. A driven clutch lever 54 is integrally rotatably supported at the upper end of the upper release shaft 61. A return spring 54s is attached to the driven clutch lever 54. The return spring 54s applies a biasing force in the direction opposite to the rotation (rotation in the clutch disengagement direction) by the operation of the clutch operator to the driven clutch lever 54.

[0061] The lower release shaft 62 is cylindrical. The lower part of the lower release shaft 62 is rotatably supported inside the right cover 17a. The lower part of the lower release shaft 62 faces into the gear case 59. An eccentric cam portion 38a of the release mechanism 38 is formed at this lower part. A lower return spring 62s is attached to the lower end of the lower release shaft 62. The lower return spring 62s applies a biasing force to the lower release shaft 62 in a direction opposite to the rotation in the clutch disengagement direction.

[0062] A manually operated side cam 61b having a sector-shaped cross section and extending in the axial direction is provided at the lower end of the upper release shaft 61. A clutch side cam 62b having a sector-shaped cross section and extending in the axial direction is provided at the upper end of the lower release shaft 62. The clutch side cam 62b is provided in a range avoiding the manually operated side cam 61b in the circumferential direction or the axial direction.

[0063] The lower end (manually operated side cam 61b) of the upper release shaft 61 and the upper end (clutch side cam 62b) of the lower release shaft 62 overlap in the axial position while avoiding each other in the circumferential direction. Or, the manually operated side cam 61b and the clutch side cam 62b overlap in the circumferential position while avoiding each other in the axial direction. Thereby, it is possible to press the other circumferential side surface 62b2 of the clutch side cam 62b with one circumferential side surface 61b1 of the manually operated side cam 61b and rotate the lower release shaft 62 (see FIGS. 9B and 10B).

[0064] The other circumferential side surface 61b2 of the manually operated side cam 61b and the one circumferential side surface 62b1 of the clutch side cam 62b are separated from each other in the circumferential direction or the axial direction. Thereby, when there is an input from the clutch actuator 50 to the clutch side cam 62b, the lower release shaft 62 can rotate independently of the upper release shaft 61 (see FIGS. 9A and 10A).

[0065] The intermediate release shaft 63 is cylindrical. The intermediate release shaft 63 can pass through the engagement portion (upper and lower shaft engagement portion) between the lower end of the upper release shaft 61 and the upper end of the lower release shaft 62. A driven gear 63a is supported on the intermediate release shaft 63 so as to be integrally rotatable. The intermediate release shaft 63 is provided with a control operation side cam 63b having a sector-shaped cross section and extending in the axial direction.

[0066] The intermediate release shaft 63 and the driven gear 63a suppress contact with other components of the clutch actuator 50. Specifically, the intermediate release shaft 63 only contacts the inner peripheral portion at the following parts in addition to the bearing supported by the gear case 59. Those parts are the lower end of the upper release shaft 61 (manual operation side cam 61b) and the upper end of the lower release shaft 62 (clutch side cam 62b). The control operation side cam 63b of the intermediate release shaft 63 engages with the following parts with an axial clearance. Those parts are the manual operation side cam 61b of the upper release shaft 61 and the clutch side cam 62b of the lower release shaft 62. Also, the driven gear 63a only contacts the gear teeth of the second small diameter gear 58b. Thereby, the friction of the driven gear 63a which is a control gear is reduced as much as possible, and the control accuracy of the release shaft 53 is improved.

[0067] The control operation side cam 63b of the intermediate release shaft 63 and the clutch side cam 62b of the lower release shaft 62 wrap the axial positions while avoiding each other in the circumferential direction. Or, the control operation side cam 63b and the clutch side cam 62b wrap the circumferential positions while avoiding each other in the axial direction. Thereby, it is possible to press the other circumferential surface 62b2 of the clutch side cam 62b with one circumferential surface 63b1 of the control operation side cam 63b and rotate the lower release shaft 62.

[0068] Further, the control operation side cam 63b is arranged so as to avoid the manual operation side cam 61b of the upper release shaft 61 in the axial direction or the radial direction. Thereby, when transmitting the input from the clutch actuator 50 to the clutch side cam 62b, the lower release shaft 62 can rotate independently of the upper release shaft 61. Further, when there is a manual operation, the upper release shaft 61 can rotate independently of the intermediate release shaft 63 on the control side.

[0069] The other circumferential side surface 63b2 of the control operation side cam 63b and the one circumferential side surface 62b1 of the clutch side cam 62b are separated from each other in the circumferential direction. Thereby, when there is an input from the manual operation side cam 61b to the clutch side cam 62b, the lower release shaft 62 can rotate independently of the intermediate release shaft 63.

[0070] Referring to FIGS. 11 and 17, the clutch actuator 50 rotatably holds the upper release shaft 61 and the intermediate release shaft 63 in the gear case 59. The clutch actuator 50 includes the upper release shaft 61 and the intermediate release shaft 63 and constitutes an integral actuator unit 50A.

[0071] The lower release shaft 62 is rotatably held by the right cover 17a. An opening 17e is provided at a step portion 17d of the cover recess 17c of the right cover 17a, and a fastening portion 17f of the gear case 59 is provided. The upper end portion of the lower release shaft 62 protrudes from the opening 17e. An opening 59c is provided at a portion of the gear case 59 facing the step portion 17d of the cover recess 17c. The opening 59c allows the upper end portion of the lower release shaft 62 to face into the gear case 59.

[0072] In such a configuration, when the actuator unit 50A is attached to the right cover 17a, a linear release shaft 53 is formed. The release shaft 53 is formed by connecting the upper release shaft 61, the intermediate release shaft 63, and the lower release shaft 62 to each other.

[0073] The power unit PU of the embodiment can be configured as follows for a manual clutch type power unit that performs the engagement and disengagement operation of the clutch device 26 by the driver's operation instead of electric control. That is, the power unit PU can be configured by replacing the right cover 17a and the release shaft 53 and retrofitting the actuator unit 50A. Therefore, the actuator unit 50A can be attached to power units of different models. Therefore, the actuator unit 50A can be shared among multiple models, and a semi-automatic transmission system (automatic clutch type transmission system) can be easily configured.

[0074] <Clutch Control> Next, the clutch control of the embodiment will be described with reference to the graph of FIG. 12. The graph of FIG. 12 images the clutch characteristics in the automatic mode M1. In the graph of FIG. 12, the vertical axis represents the torque (Nm) applied to the driven clutch lever 54 and the clutch capacity (%), and the horizontal axis represents the operating angle (deg) of the driven clutch lever 54. The operating angle of the driven clutch lever 54 is the operating angle of the lower release shaft 62.

[0075] The torque of the driven clutch lever 54 is the generated torque of the lower release shaft 62. This torque corresponds to the torque value obtained by multiplying the following primary torque value by the reduction ratio of the reduction mechanism 51. The primary torque value is obtained based on the supply current value to the motor 52 from the correlation between the supply current to the motor 52 and the torque generated by the motor 52. Hereinafter, the torque of the driven clutch lever 54 is referred to as the driven clutch lever torque. The correlation between the driven clutch lever operating angle and the driven clutch lever torque is indicated by the graph center line L11. The correlation between the driven clutch lever operating angle and the clutch capacity is indicated by the graph center line L12. The line L11 is also a line indicating the output value (reference output value) of the clutch actuator 50 when engaging and disengaging the clutch device 26 without manual operation intervention.

[0076] In the auto mode M1 of the normal closed clutch, when the torque of the driven clutch lever (motor output) is "0", there is no operation input to the clutch device 26 (input to the disconnection side), and the clutch capacity becomes 100%. That is, the clutch device 26 maintains the connected state. This state corresponds to the region A on the horizontal axis in FIG. 12. Region A is the play region of the driven clutch lever 54. In region A, there is no motor output, and the torque of the driven clutch lever transitions to "0". In region A, the clutch device 26 does not operate, and the clutch capacity transitions to 100%.

[0077] Referring also to FIG. 8, in region A, one circumferential side surface 61b1 of the manual operation side cam 61b of the release shaft 53 does not press the other circumferential side surface 62b2 of the clutch side cam 62b. At this time, the manual operation side cam 61b is separated from the clutch side cam 62b by the biasing force of the return spring 54s (shown by the dashed line in FIG. 8). In region A, the driven clutch lever 54 is in a play state where the manual operation side cam 61b can approach and separate from the clutch side cam 62b by an angle A1 in the figure. For example, in region A, one circumferential side surface 63b1 of the control operation side cam 63b is in contact with the other circumferential side surface 62b2 of the clutch side cam 62b.

[0078] Referring to FIG. 12, when the operating angle of the driven clutch lever increases and passes through the play region A, the operating angle of the driven clutch lever transitions to the half-clutch region B. In the half-clutch region B, the torque of the driven clutch lever starts to increase due to the operation of the motor 52.

[0079] Referring also to Fig. 9A, in the semi-clutch region B, the control operation side cam 63b presses the clutch side cam 62b to rotate the lower release shaft 62. When the driven clutch lever torque increases, the release mechanism 38 lifts the clutch device 26 to reduce the clutch capacity. That is, the clutch device 26 enters a semi-clutch state allowing partial power transmission. In Fig. 12, the symbol SP indicates the start position (operation start position) of the operation switching from the play region A to the semi-clutch region B. In the semi-clutch region B, when a manual operation intervenes, the manual operation side cam 61b abuts against the clutch side cam 62b. At this time, the manual operation side cam 61b cooperates with the control operation side cam 63b to rotate the lower release shaft 62 (see Fig. 9B).

[0080] Referring to Fig. 12, in the semi-clutch region B, the driven clutch lever torque increases steeply as the driven clutch lever operating angle increases, and the clutch device 26 is actuated toward the disconnection side. For example, at the initial stage of the semi-clutch region B, there is an influence of the clutch judder spring reaction force (not shown). As a result, at the initial stage of the semi-clutch region B, a deceleration region B1 is set to moderate the increase in the driven clutch lever torque with respect to the increase in the driven clutch lever operating angle. In the semi-clutch region B, the clutch capacity decreases steeply as the driven clutch lever operating angle increases so as to be inversely proportional to the increase in the driven clutch lever torque. In the initial deceleration region B1 of the semi-clutch region B, the decrease in the clutch capacity is moderated as the increase in the driven clutch lever torque becomes moderate.

[0081] When the operating angle of the driven clutch lever exceeds the touch point TP which is the end point of the half-clutch region B, the increase in the torque of the driven clutch lever becomes gentler than that in the deceleration region B1. The region after the touch point TP at the operating angle of the driven clutch lever becomes, for example, a clutch disengagement region C where the clutch capacity remains equivalent to "0". The clutch disengagement region C is, for example, an operating margin region for the driven clutch lever 54 etc. to operate up to the mechanical operating limit position. In the clutch disengagement region C, the torque of the driven clutch lever slightly increases. This increase corresponds to the increase in the clutch spring load accompanying the movement of the lift parts of the clutch device 26. The symbol EP in Fig. 12 indicates the full lift position which is the end point of the clutch disengagement region C.

[0082] For example, a standby position DP is set in the middle of the clutch disengagement region C. At the standby position DP, the following torque of the driven clutch lever is applied. The torque of the driven clutch lever at this time is slightly higher than the torque at the touch point TP where the clutch device 26 starts connection. At the touch point TP, some torque transmission may occur due to operating errors. In contrast, by applying the torque of the driven clutch lever up to the torque at the standby position DP, the torque transmission of the clutch device 26 is completely blocked. Also, at the standby position DP, by applying a driven clutch lever torque slightly lower than that at the full lift position EP, it becomes possible to perform ineffective packing of the clutch device 26. That is, at the standby position DP, it becomes possible to cancel the play of each part and the operating reaction force in the clutch device 26, and the operating responsiveness at the time of connection of the clutch device 26 can be enhanced.

[0083] When the clutch device 26 operates from the connected state to the disconnection side, the operating start position SP and the touch point TP are determined as follows. That is, the point where the torque of the driven clutch lever rises (the start point of the half-clutch region B) is the operating start position SP. Also, the point where the clutch device 26 is completely disengaged (the end point of the half-clutch region B) is the touch point TP. Conversely, when the clutch device 26 operates from the disengaged state to the engaged side, the touch point TP and the operation start position SP are determined as follows. That is, the point at which the clutch device 26 starts to engage is the touch point TP. Also, the point at which the clutch device 26 is fully engaged is the operation start position SP.

[0084] Referring to FIG. 13, in the semi-clutch region B, the drive of the motor 52 is controlled based on the lift load. In such control, first, a clutch spring load is set in advance based on the elastic force of the clutch spring 37. Next, a lift load (an operating load against the clutch spring load) acting on the clutch device 26 is estimated according to the torque of the driven clutch lever. Then, the load obtained by subtracting the lift load from the clutch spring load is used as the clutch pressing load actually acting on the clutch device 26.

[0085] The clutch capacity is obtained by "clutch pressing load / clutch spring load". The power supplied to the motor 52 is controlled so that the clutch capacity becomes the target value, and the torque of the driven clutch lever and thus the lift load are controlled. The motor current value and the lever operating angle at each of the operation start position SP and the touch point TP are set to default values in advance. Alternatively, as will be described later, the motor current value and the lever operating angle are set by learning control when the power of the motorcycle 1 is turned on or off.

[0086] As an example of the sensing configuration, the following configuration can be mentioned. That is, a current sensor 40b is provided in the motor control device (clutch control unit 40C), and the detected value is converted into motor torque and further into the torque of the driven clutch lever (clutch operation torque).

[0087] As shown in FIG. 13, in the semi-clutch region B, when there is an intervention in the operation (manual operation) of the clutch lever, the following actions occur. That is, with respect to the correlation line L11 of the pre-set driven clutch lever torque, the measured value of the driven clutch lever torque decreases (see part F in the figure). At this time, if the decrease amount of the driven clutch lever torque exceeds a pre-determined threshold value d1, it is determined that there has been an intervention in the manual operation, and a shift is made to a pre-determined manual operation intervention control.

[0088] In the manual operation intervention control, for example, after detecting the manual operation intervention, the following control is performed until the increase amount of the driven clutch lever operating angle becomes equal to or greater than a pre-determined angle. That is, the motor 52 is feedback-controlled so as to maintain the torque d2 after the driven clutch lever torque has decreased by the threshold value d1. During the current control at this time, a current limit corresponding to the angle is provided after the touch point TP. For this reason, the motor output becomes almost zero during the current control. Since the load at that time is sufficiently low, it is determined that a manual intervention has occurred. Thereby, it is possible to suppress the sense of discomfort caused by the sudden disappearance of the torque from the motor 52 after the operation of the clutch lever. After the increase amount of the driven clutch lever operating angle becomes equal to or greater than the specified angle, the driven clutch lever torque is gradually decreased (see part G in the figure). Thereby, while suppressing the sense of discomfort, it is possible to suppress the power consumption caused by continuously driving the motor 52.

[0089] In the clutch disengagement region C, the drive of the motor 52 is controlled based on the lever position (angle). As described above, in the clutch disengagement region C, the increase in the driven clutch lever torque accompanying the lift of the clutch device 26 is small. For this reason, in the clutch disengagement region C, the power supplied to the motor 52 is controlled based on the driven clutch lever operating angle. Thereby, it becomes possible to more finely control the disengagement amount of the clutch device 26 after the touch point TP where the clutch device 26 starts to connect.

[0090] As an example of the sensing configuration, the following configuration can be mentioned. That is, a first rotation angle sensor 57d and a second rotation angle sensor 58d are provided on the first reduction shaft 57 and the second reduction shaft 58, respectively. And it can be mentioned that the detection values of these respective sensors are converted into the driven clutch lever operating angle (clutch operation angle). The first rotation angle sensor 57d and the second rotation angle sensor 58d are provided in a pair for fail-safe, but only one of them may be used.

[0091] As shown in FIG. 13, in the clutch disengagement region C, when there is an intervention in the operation (manual operation) of the clutch lever, the following actions occur. That is, the measured value of the driven clutch lever torque decreases with respect to the correlation line L11 of the preset driven clutch lever torque (see part H in the figure).

[0092] Referring also to FIG. 10A, for example, in the auto mode M1, the torque applied by the control operation side cam 63b to the clutch side cam 62b is limited to the torque until reaching the standby position DP. The torque until the clutch side cam 62b reaches the full lift position EP beyond the standby position DP is applied when a manual operation of squeezing the clutch lever intervenes. At this time, only the torque beyond the standby position DP is applied from the manual operation side cam 61b to the clutch side cam 62b (see FIG. 10B). At this time, the control operation side cam 63b separates from the clutch side cam 62b, and the motor output becomes substantially 0.

[0093] Even before reaching the standby position DP, if the driven clutch lever operating angle is in the clutch disengagement region C beyond the touch point TP, the following actions occur. That is, due to the intervention of the manual operation, the measured value of the driven clutch lever torque becomes substantially 0. Therefore, in the clutch disengagement region C, when the measured value of the driven clutch lever torque changes to a range where it becomes substantially 0, it is determined that there has been an intervention of the manual operation. And it shifts to the preset manual operation intervention control.

[0094] In the manual operation intervention control, for example, after detecting the manual operation intervention, the following control is performed until the increase in the operating angle of the driven clutch lever becomes equal to or greater than a predetermined angle. That is, the motor output is held so that the operating angle of the driven clutch lever maintains the touch point TP which is the substantial clutch disengagement position. This suppresses the occurrence of engine stalls even when the clutch lever is suddenly released after the manual operation intervenes.

[0095] In this way, by properly using the load (current) control and the position (angle) control according to the situation of the clutch device 26, it becomes possible to perform more detailed clutch control (optimal control according to the state and characteristics of the clutch device 26). In the embodiment, the operating angle of the driven clutch lever (the rotation angle of the gear shaft of the speed reduction mechanism 51) is detected and the following control is performed. That is, in the region (semi-clutch region B) up to the preset (or learned) touch point TP, the control is such that the reference of the current value is increased. In the region after the touch point TP (clutch disengagement region C), the control is such that the reference of the operating angle is increased.

[0096] FIG. 18 is a functional block diagram related to the switching control for switching between the semi-clutch region B and the clutch disengagement region C in the embodiment. In the block diagram at the lower part of the figure, the following is shown as the control for increasing the weighting of the motor current (clutch capacity, load) in the semi-clutch region B. That is, friction correction is added to the motor current corresponding to a predetermined target clutch capacity to obtain a target current value. From the relationship between this target current value and the current clutch position, the current limit for manual intervention determination is determined. And if the clutch position enters the disengagement region during the semi-clutch control, it is determined that there has been a manual intervention. Reference numeral 71 in the figure indicates a first information generation unit that generates information for manual intervention determination based on the clutch capacity (load) in the semi-clutch region B.

[0097] In the block diagram in the upper part of the figure, the following content is shown as control for increasing the weighting of the clutch operating angle (clutch position) in the clutch disengagement region C. That is, with respect to the difference between the target clutch position and the current clutch position, the clutch operating speed is further taken into account to obtain the "current value (torque) according to the speed / position deviation". In parallel with this, friction correction is added to the base current determined in advance according to the target clutch position to obtain the target current value. The target current value and the current value according to the deviation are added to determine the current limit during continuous holding. And when the load current becomes below a certain value during the clutch disengagement control, it is determined that there is manual intervention. Reference numeral 72 in the figure indicates a second information generation unit that generates information for manual intervention determination based on the clutch position in the clutch disengagement region C.

[0098] Also, in the embodiment, the change in the current value (converted to torque value) of the motor 52 with respect to the driven clutch lever operating angle is learned (updated) at a predetermined timing. Thereby, a target value (current value) according to the situation of the clutch device 26 is set. Based on this target value and the detection value of the current sensor 40b of the clutch control unit 40C, the drive of the motor 52 is feedback-controlled.

[0099] <Correction of control reference value> Next, the control for learning the current and angle at the touch point TP and the like in the embodiment will be described with reference to the graph in FIG. 14. The graph in FIG. 14 shows how the correlation line L11 showing the clutch characteristics shown in FIGS. 12 and 13 changes. This change occurs according to the wear of the clutch plate 35 and the temperature of the engine 13 (for example, coolant temperature). In FIG. 14, the vertical axis represents the torque (Nm) of the driven clutch lever, and the horizontal axis represents the operating angle (deg) of the driven clutch lever.

[0100] In an embodiment, for example, when the main switch (power supply) of the motorcycle 1 is turned on or off, the zero points (operation start position SP and touch point TP) during clutch capacity control are corrected. In the current control of the motor 52, temperature changes affect the motor torque. For this reason, the height of the correlation line L11 changes depending on the temperature (see J in the figure). Therefore, for example, zero point correction is performed in each of a plurality of temperature ranges such as whether the engine temperature is 80 degrees or higher (whether the engine has warmed up). The zero points at this time are stored in the memory and used for the next clutch capacity control.

[0101] An example of the procedure for setting (learning) the operation start position SP and the touch point TP will be described. First, for example, when the power supply of the clutch control unit 40C is turned on or off, the clutch actuator 50 is operated. At this time, the change in the current value until the clutch device 26 is disengaged is measured. Next, the slope (change rate) of the change in the current value when reaching from the play area A to the half-clutch area B is detected. Also, the slope (change rate) of the change in the current value when reaching from the half-clutch area B to the clutch disengagement area C is detected. The point at which the former slope becomes equal to or greater than the threshold value is set as the operation start position SP. The point at which the latter slope becomes equal to or less than the threshold value is set as the touch point TP. As an alternative, the following part may be learned as the operation start position SP. That part is the part where the current is increased linearly from the clutch play area and the angular velocity of the rotation angle sensor starts to decelerate from the point where it has accelerated (the part where the maximum speed is reached). Conversely, the following part may be learned as the touch point TP. That part is the part where the current is decreased linearly from the clutch disengaged state (held in the area) and the angular velocity of the rotation angle sensor starts to decelerate from the point where it has accelerated (the part where the maximum speed is reached).

[0102] Also, at the same timing as described above, it is determined whether a decrease of a specified value or more has occurred in the driven clutch lever operating angle. If the driven clutch lever operating angle has decreased significantly, there may be wear of the clutch plate 35.

[0103] That is, in a normal closed clutch, when the clutch plate 35 wears, the lifter shaft 39 moves to the side away from the release mechanism 38. As a result, when the clutch plate 35 wears, the play of the release mechanism 38 decreases. Thereby, the release shaft 53 operates the clutch device 26 to the disengaging side with a small operating angle. Thereby, at the operating start position SP where the switching from the play region A to the semi-engaged region B starts, the driven clutch lever operating angle decreases (see K in the figure). Therefore, when the driven clutch lever operating angle at the operating start position SP has decreased to a specified value or more, it is possible to predict that the clutch plate 35 is worn. When the wear of the clutch plate 35 is predicted (detected), a warning can be given to the user by using the indicator 40d (see FIG. 3) provided in the meter device or the like.

[0104] The motor current and the lever operating angle at the touch point TP and the like are learned every time the power of the motorcycle 1 is turned on or off. Thereby, it becomes possible to perform control using the touch point TP and the like with high accuracy. Also, it becomes possible to predict (detect) the wear of the clutch plate 35. Based on the relationship between the lever operating angle and the motor current, the motor current and the lever operating angle at the touch point TP where the clutch device 26 starts to connect are learned. Thereby, it becomes possible to perform clutch control in consideration of the effects of friction, wear, and temperature.

[0105] <2-Motor Control> In an embodiment, two motors 521 and 522 in the clutch actuator 50 may cooperate to drive the release shaft 53 (to engage and disengage the clutch device 26). In this case, by halving the load shared by the two motors 521 and 522, the size of each motor 521 and 522 can be reduced. As a result, the degree of freedom in the layout of the motor 52 increases compared to the case where a large single motor 52 is provided. For this reason, as shown in FIGS. 15 to 17, even when the clutch actuator 50 is arranged on the outer side of the power unit PU, it is easy to suppress the protrusion of the clutch actuator 50 outward in the vehicle width direction. Therefore, it is possible to substantially reduce the size of the clutch control device 40A.

[0106] When driving the two motors 52, if the resistance values are different from each other due to individual differences in each motor 52, the following possibilities exist. That is, even if the same DUTY is applied to each motor 52, the current flowing through only one of the two motors 52 may increase. That is, even if the same DUTY is applied to the two motors 52, the amount of current flowing through both of them may vary depending on solid variations, temperature conditions, and the like.

[0107] Referring to FIG. 19, in the embodiment, when controlling the release shaft 53 to a target angle, a configuration is adopted in which the current value is feedback-controlled in an inner loop. That is, in each motor 52, PID control is performed based on the difference between the target current and the current at present. In parallel with this control, a base DUTY set in advance according to the target current is obtained, and these are added to determine the DUTY of each motor 52. By making the control loop a cascade configuration and controlling the current, the influence of temperature can be resolved within the current feedback loop. Reference numeral 73 in the figure indicates a DUTY information generation unit that generates DUTY information of each motor 52 based on the target current and the current at present.

[0108] Also, by driving the two motors 52, it becomes possible to halve the load borne by each motor 52. Therefore, the variation in the calorific value of each motor 52 can be suppressed. As a result, the temperature influence of each motor 52 during the operation of the clutch actuator can be reduced.

[0109] In the clutch actuator 50, during normal operation (non-failure), one of the plurality (two) of motors 52 may be used as the drive source for the release shaft 53, and the remaining one may be used for other purposes. For example, the remaining one motor 52 may be kept inoperative for fail-safe or used as a current sensor.

[0110] When one motor 52 fails, the friction of the clutch actuator 50 when holding the clutch position increases. It also affects the response speed of the clutch drive. In the embodiment, even if one motor 52 fails on the system, within the one-fail range, the following countermeasures are taken. That is, by once releasing (turning OFF) the clutch, the influence on the vehicle body behavior is suppressed.

[0111] Referring to FIG. 20, each motor 52 is driven and controlled by a common clutch control unit 40C during normal operation (non-failure). The in-vehicle power supply battery BT is connected to the current supply line of one motor 52 via a fail-safe relay 40F. The engine control unit 40E is connected to the fail-safe relay 40F via a control line. In FIG. 20, the fail-safe relay 40F is connected only to one motor 52. Alternatively, a configuration in which the fail-safe relay 40F is connected to each of the two motors 52 may be adopted.

[0112] When a failure occurs in one of the motors 52, the following countermeasures are taken. That is, by driving the fail-safe relay 40F via the engine control unit 40E, the control of the motor 52 to which the fail-safe relay 40F is connected is temporarily taken over. As a result, it is possible to realize control that gradually connects from clutch disconnection. Also, similarly, when a failure occurs in the clutch control unit 40C, the motor 52 to which the fail-safe relay 40F is connected can be controlled by the engine control unit 40E. Note that when the engine control unit 40E and the fail-safe relay 40F fail, the driving of the motor 52 is continued by the clutch control unit 40C.

[0113] Referring to FIG. 21, when one of the two motors 521 and 522 becomes inoperable (during a single failure), the remaining motor is driven to disconnect the clutch device 26. In the embodiment, the clutch device 26 is driven to the standby position DP or the full lift position EP (point M in the figure). Thereafter, as control to gradually connect the clutch device 26 from the disconnected state, the control position (angle) of the clutch device 26 is returned to the capacity 0 line (corresponding to the touch point TP) (point N in the figure). Thereafter, the fail-safe relay 40F is intermittently driven to gradually connect the clutch device 26. In this control, the motor 52 can be emergently controlled from a route different from the normal control route (control by the clutch control unit 40C) (control by the engine control unit 40E). By intermittently driving the clutch device 26 in this way and gradually connecting it, the vehicle body behavior can be gently suppressed.

[0114] As described above, the clutch control device in the above embodiment includes a clutch device 26 that disconnects and connects the power transmission between the engine 13 and the transmission 21, a clutch actuator 50 that outputs a driving force for operating the clutch device 26, and a control unit 40 that drives and controls the clutch actuator 50. The clutch actuator 50 includes a plurality of motors 521 and 522 that output the driving force. According to this configuration, since the clutch actuator 50 includes a plurality of motors 521 and 522, the load on each motor 521 and 522 can be reduced, and the size can be reduced. Also, a fail-safe of the clutch drive system can be achieved by the plurality of motors 521 and 522.

[0115] Also, in the above clutch control device, the control unit 40 performs feedback control on the current supplied to each of the plurality of motors 521 and 522. According to this configuration, by performing feedback control on the supply current to each motor 521 and 522 toward the target value, the variation in load among the plurality of motors 521 and 522 can be suppressed.

[0116] Also, in the above clutch control device, the control unit 40 includes a clutch control unit 40C and an engine control unit 40E that are independent of each other. Each of the plurality of motors 521 and 522 can be independently controlled by either the clutch control unit 40C or the engine control unit 40E. According to this configuration, either the clutch control unit 40C or the engine control unit 40E can drive the normal ones among the plurality of motors 521 and 522. Therefore, the driving of the clutch actuator 50 can be continued. This effect can be obtained even if one of the plurality of motors 521 and 522 fails or one of the clutch control unit 40C and the engine control unit 40E malfunctions, rendering one of the plurality of motors 521 and 522 inoperable.

[0117] Also, in the above clutch control device, when one of the plurality of motors 521 and 522 becomes inoperable, the remaining ones of the plurality of motors 521 and 522 temporarily disconnect the clutch device 26, and then gradually connect the clutch device 26. According to this configuration, even when an abnormality occurs in the driving of one of the plurality of motors 521 and 522, it is possible to prevent the clutch device 26 from being maintained in the connected state. Further, after the clutch device 26 is disengaged, by gradually shifting to the connected state, it is possible to suppress a change in the behavior of the vehicle.

[0118] Also, in the above clutch control device, when one of the plurality of motors 521 and 522 becomes inoperable, the drive current when driving the remaining ones of the plurality of motors 521 and 522 is set to be larger than that during normal driving before the failure. Thereby, when one of the plurality of motors 521 and 522 fails, it is possible to prevent a shortage of power. On the other hand, the process of reconnecting the clutch device 26 after once disconnecting it has the following effect when configured to perform only one cycle. That is, the actuator is driven with a current value larger than the normal control amount, and is driven and stopped at the fail stop position in one cycle. Thereby, it is possible to shift to the fail mode while suppressing heat generation and the like with a minimum amount of operation.

[0119] Note that the present invention is not limited to the above embodiments. For example, the clutch operator is not limited to a clutch lever, and may be a clutch pedal or other various operators. The clutch device is not limited to being disposed between the engine and the transmission, and may be disposed between any output target other than the prime mover and the transmission. The prime mover is not limited to an internal combustion engine and may be an electric motor. The present invention is not limited to the application to a straddle-type vehicle in which the clutch operation is automated as in the above embodiment. For example, it is also applicable to a straddle-type vehicle that enables shifting by adjusting the driving force without performing a manual clutch operation under predetermined conditions while being based on a manual clutch operation (a straddle-type vehicle equipped with a so-called clutchless transmission). In addition, the straddle-type vehicle includes all vehicles in which the driver rides while straddling the vehicle body, including not only motorcycles (including motor bicycles and scooter-type vehicles), but also three-wheeled (including vehicles with one front wheel and two rear wheels, as well as vehicles with two front wheels and one rear wheel) or four-wheeled vehicles, and also includes vehicles having an electric motor as a prime mover. The configurations in the above embodiments are examples of the present invention, and various modifications can be made without departing from the gist of the present invention.

Explanation of Reference Numerals

[0120] 1 Motorcycle (straddle-type vehicle) 13 Engine (prime mover) 17a Right cover (cover) 21 Transmission (output target) 26 Clutch device 38 Release mechanism 50 Clutch actuator 53 Release shaft 59 Gear case (case) 61 Upper release shaft (first release shaft) 61b Manual operation side cam 62 Lower release shaft (second release shaft) 63 Intermediate release shaft (third release shaft) 63a Driven gear 63b Control operation side cam

Claims

1. A clutch device (26) for connecting and disconnecting the power transmission; a clutch actuator (50) that outputs a driving force for operating the clutch device (26); a release mechanism (38) that receives a driving force of the clutch actuator (50) and operates the clutch device (26); In the transmission system, the release mechanism (38) includes a release shaft (53) that transmits a driving force of the clutch actuator (50) to the clutch device (26), The release shaft (53) is configured by linearly arranging a first release shaft (61) which is rotated by manual operation by an occupant, a second release shaft (62) which is made rotatable by the clutch actuator (50), and a third release shaft (63) which is rotated by rotation of the first release shaft (61) and the second release shaft (62) and which actuates the clutch device (26), The first release shaft (61) is rotated by manual input from a passenger, and the rotation can rotate the third release shaft (63) independently of the rotation of the second release shaft (62) by the clutch actuator (50).

2. 2. The transmission system according to claim 1, wherein the clutch device (26) is provided with a cover (17a) that covers the clutch device (26) from the outside, the third release shaft (63) is rotatably supported by the cover (17a), and the first release shaft (61) and the second release shaft (62) are rotatably supported by a gear case (59) that is arranged in the clutch actuator (50).

3. 3. The transmission system according to claim 1 or 2, wherein the release mechanism (38) has the first release shaft (61) at an upper portion and the third release shaft (63) at a lower portion, and the second release shaft (62) is disposed between the first release shaft (61) and the third release shaft (63).

4. The third release shaft (63) is cylindrical, and an engagement portion between a lower end of the first release shaft (61) and an upper end of the second release shaft (62) can be inserted therethrough. The third release shaft (63) is supported so as to be integrally rotatable with a driven gear (63a), 4. The transmission system according to claim 1, wherein the third release shaft (63) is provided with a control operation side cam (63b) that has a sector-shaped cross section and extends in the axial direction.

5. 5. The transmission system according to claim 4, wherein a joint between the first release shaft (61) and the second release shaft (62) is disposed within a cylinder of the third release shaft (63).

6. The third release shaft (63) is cylindrical, and an engagement portion between a lower end of the first release shaft (61) and an upper end of the second release shaft (62) can be inserted therethrough. The third release shaft (63) is supported so as to be integrally rotatable with a driven gear (63a), 2. The transmission system according to claim 1, wherein the third release shaft (63) is provided with a control operation side cam (63b) extending in the axial direction and having a sector-shaped cross section.

7. 7. The transmission system according to claim 6, wherein the control operation side cam (63b) is arranged so as to avoid the manual operation side cam (61b) of the first release shaft (61) in the axial or radial direction.

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