Vehicle

Abstract

A vehicle (1) is provided. The vehicle (1) is provided with a control unit that switches between a constant speed running mode in which a vehicle speed (V) is kept constant and an inertia running mode in which a prime mover is stopped or idling, and a clutch device that disconnects or connects power transmission between the prime mover and an output target, wherein the control unit controls the clutch device to decrease a clutch capacity (Cap) to shift to the inertia running mode when it is detected that the vehicle is running on a downhill, and controls the clutch device to increase the clutch capacity (Cap) to shift to the constant speed running mode when it is detected that the downhill has ended.

Description

[0001] This application claims priority based on Japanese Patent Application No. 2021-160711, filed on September 30, 2021, the contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to vehicles. Background Technology

[0003] Previously, in hybrid vehicles, there were known technologies that improved fuel efficiency by stopping the engine while driving (see, for example, Japanese Patent Application Publication No. 2006-74931). Summary of the Invention

[0004] Summary of the invention

[0005] The problem that the invention aims to solve

[0006] However, in recent years, as a technology to improve fuel efficiency by stopping the engine while driving, there is a technology that can implement a coasting mode that allows the vehicle to coast without engine braking by disengaging the clutch when going downhill.

[0007] In coasting mode, the vehicle speed varies depending on the distance and gradient of the downhill slope, so this needs to be considered when combined with cruise mode, which maintains a constant speed.

[0008] In the process of researching a clutch control device that controls the disengagement of a clutch assembly, the applicant gained insights into the combination of coasting mode and cruise mode.

[0009] That is, the solution of the present invention can efficiently combine coasting mode and cruise mode in a vehicle that controls the disengagement of the clutch device.

[0010] (1): A vehicle according to one aspect of the present invention includes a control unit 40 and a clutch device 26. The control unit 40 switches between a constant speed driving mode that keeps the vehicle speed V constant and an inertial driving mode that puts the prime mover 13 into a stopped or idling state. The clutch device 26 disconnects or connects the power transmission between the prime mover 13 and the output object 21. In the constant speed driving mode, when the control unit 40 detects that it is driving downhill, it controls the clutch device 26 to decrease the clutch capacity Cap and switch to the inertial driving mode. When the downhill is detected to have ended, it controls the clutch device 26 to increase the clutch capacity Cap and switch back to the constant speed driving mode.

[0011] According to the structure of the above (1) scheme, when a vehicle equipped with this clutch control device is going downhill in constant speed driving mode, the clutch capacity decreases (becoming a clutch disengaged state) and it switches to inertial driving mode. When the downhill driving ends, the inertial driving mode ends and it returns to constant speed driving mode. In this way, by appropriately switching between inertial driving mode and constant speed driving mode, fuel efficiency can be improved while suppressing discomfort.

[0012] (2): Based on the above (1) scheme, when the control unit 40 detects that the vehicle speed V increases and becomes above the threshold V2 in the inertial driving mode, it increases the clutch capacity Cap to generate engine braking.

[0013] According to the structure of the above (2) scheme, when the vehicle speed increases to above a certain level due to downhill driving in inertial driving mode, the clutch capacity is increased to generate engine braking, thereby allowing for easy speed adjustment through clutch control. Engine braking can be adjusted by changing the working number of the ports in the internal combustion engine (variable valve, cylinder deactivation, etc.) or by the exhaust valve located in the exhaust passage.

[0014] (3): Based on the above (1) scheme, when the control unit 40 detects that the braking device is working in the inertial driving mode, it increases the clutch capacity Cap according to the operation amount of the braking device to generate engine braking.

[0015] According to the structure of the above (3) scheme, when the braking device is activated by the driver's operation in the inertial driving mode, the clutch capacity is increased in response to the operation of the braking device to generate engine braking, thereby enabling efficient braking assistance through clutch control.

[0016] (4): Based on any of the above (1) to (3), when the downhill driving ends and the inertial driving mode ends and the vehicle returns to the constant speed driving mode, the control unit 40 controls the clutch capacity Cap so that the current vehicle speed V is consistent with the target vehicle speed V1 of the constant speed driving mode.

[0017] According to the structure of the above scheme (4), when the inertial driving mode ends and the vehicle returns to the constant speed driving mode at the same time as the downhill end, the clutch capacity is controlled by comparing the current vehicle speed with the target vehicle speed of the constant speed driving mode. As a result, the current vehicle speed can be quickly converged to the target vehicle speed of the constant speed driving mode after the inertial driving mode, and the constant speed driving mode can be efficiently restored while suppressing discomfort.

[0018] (5): Based on the above (4) scheme, when the downhill driving ends and the inertial driving mode ends and returns to the constant speed driving mode, the control unit 40 calculates the required engine speed according to the set gear ratio and vehicle speed V, and increases the clutch capacity Cap when the engine speed reaches or exceeds the required engine speed.

[0019] According to the structure of the above scheme (5), the clutch capacity is increased when the required engine speed is reached, thus suppressing the discomfort when returning to constant speed driving mode. The increase in the required engine speed is achieved by adjusting the throttle opening and fuel injection quantity using the control unit.

[0020] According to the present invention, in a vehicle that controls the disengagement of the clutch device, it is possible to efficiently combine coasting mode and cruise mode. Attached Figure Description

[0021] Figure 1 This is a right-side view of the motorized two-wheeled vehicle according to this embodiment.

[0022] Figure 2 This is a cross-sectional view of the transmission and shifting mechanism of the aforementioned motorized two-wheeled vehicle.

[0023] Figure 3 This is a block diagram of the transmission system of the aforementioned motorized two-wheeled vehicle.

[0024] Figure 4 This is an explanatory diagram showing the change in clutch control mode of the aforementioned motorized two-wheeled vehicle.

[0025] Figure 5 yes Figure 1 The V-direction view represents the axial view of the clutch actuator.

[0026] Figure 6 This is a cross-sectional view of the aforementioned clutch actuator along its axial direction.

[0027] Figure 7 This is a three-dimensional view of the release shaft that enables the clutch mechanism to operate.

[0028] Figure 8 yes Figure 7 Sectional view of VIII-VIII.

[0029] Figure 9A This represents the function of the aforementioned split shaft in the semi-engaged region. Figure 8 A corresponding sectional view showing the drive via the clutch actuator.

[0030] Figure 9BThis represents the function of the aforementioned split shaft in the semi-engaged region. Figure 8 A comparable sectional view, indicating manual intervention.

[0031] Figure 10A This indicates the function of the aforementioned separation shaft in its standby position. Figure 8 A corresponding sectional view showing the drive via the clutch actuator.

[0032] Figure 10B This indicates the function of the aforementioned separation shaft in its standby position. Figure 8 A comparable sectional view, indicating manual intervention.

[0033] Figure 11 This refers to the state where the aforementioned clutch actuator is installed on the right cover. Figure 6 A comparable sectional view.

[0034] Figure 12 It is a line graph representing the characteristics of clutch control. The vertical axis represents the output value of the clutch actuator, and the horizontal axis represents the workload of the disengagement mechanism.

[0035] Figure 13 Is with Figure 12 A corresponding line diagram illustrates the function of the implementation method.

[0036] Figure 14 It is a time graph showing the various states of a motorized two-wheeled vehicle when it travels from flat ground downhill and back to flat ground while in cruise mode.

[0037] Figure 15 It means Figure 14 The time graph of the variant example represents an example of a motorized two-wheeled vehicle exceeding a threshold speed while traveling in coasting mode.

[0038] Figure 16 It means Figure 14 Another variation of the time diagram shows an example of a motorized two-wheeled vehicle braking while traveling in coasting mode.

[0039] Figure 17 This is a flowchart illustrating the process of switching between coasting mode and cruise mode. Detailed Implementation

[0040] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the orientations of front, back, left, and right in the following description are the same as those in the vehicle described below. Furthermore, arrows indicating the front of the vehicle (FR), the left side of the vehicle (LH), and the top of the vehicle (UP) are shown in appropriate locations in the accompanying drawings used in the following description.

[0041] <Vehicle as a whole>

[0042] like Figure 1 As shown, this embodiment applies to a motorized two-wheeled vehicle 1, which is an example of a straddle-type vehicle. The front wheel 2 of the motorized two-wheeled vehicle 1 is supported on 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 on the head tube 6 at the front end of the frame 5 via a steering rod 4. A rod-type handlebar 4a is mounted on the top bridge of the steering rod 4.

[0043] The frame 5 includes a head tube 6, a main frame 7 extending rearward and downward from the center of the head tube 6 in the width direction (left-right direction), a pivot frame 8 disposed 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 the swing arm 11 is pivotally supported on the pivot frame 8. The rear wheel 12 of the motorized two-wheeled vehicle 1 is supported at the rear end of the swing arm 11.

[0044] 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 behind the fuel tank 18 and above the seat frame 9. Knee grip portions 18a are formed on the left and right sides of the rear portion of the fuel tank 18, recessed inwards in the vehicle width direction. The left and right knee grip portions 18a are formed to mate with the inner sides of the left and right knees of the driver seated in the front seat 19. Footrests 18b for the driver to place their ankles and toes are supported on the left and right sides below the front seat 19.

[0045] Below the main frame 7, there is a power unit PU that includes the prime mover of the motorized two-wheeled vehicle 1. The power unit PU has an engine (internal combustion engine, prime mover) 13 located at its front and a transmission (output device) 21 located at its rear. The engine 13 is, for example, a multi-cylinder engine that rotates the crankshaft 14 in the left-right direction (vehicle width direction).

[0046] Engine 13 causes cylinder 16 to stand upright above the front of crankcase 15. The rear of crankcase 15 houses transmission housing 17. A right cover 17a, extending across the right side of transmission housing 17, is mounted on the right side of crankcase 15. Right cover 17a also serves as a clutch cover over clutch assembly 26. Power unit PU operates in conjunction with rear wheel 12, for example, via a chain drive mechanism (not shown).

[0047] <Transmission>

[0048] Refer to together Figure 2 The transmission 21 is a stepped transmission having a main shaft 22, an intermediate shaft 23, and a gear set 24 spanning the two shafts 22 and 23. The intermediate shaft 23 constitutes the output shaft of the transmission 21 and even the power unit PU. The left end of the intermediate shaft 23 protrudes to the rear left side of the transmission housing 17 and is connected to the rear wheel 12 via the chain drive mechanism.

[0049] The main shaft 22 and intermediate shaft 23 of the transmission 21 are located behind the crankshaft 14. A clutch device 26 is coaxially disposed at the right end of the main shaft 22. The clutch device 26 disconnects or 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 engaged or disengaged by at least one of the following: operation of the clutch operating element by the occupant, and operation of the clutch actuator 50, which will be detailed later. For example, the clutch operating element is the clutch release lever 4b.

[0050] The clutch device 26 is, for example, a wet multi-plate clutch, a so-called normally closed clutch. The rotational power of the crankshaft 14 is transmitted to the main shaft 22 via the clutch device 26, and from the main shaft 22 to the intermediate shaft 23 via any gear pair of the transmission gear set 24. The drive sprocket 27 of the chain drive mechanism is mounted on the left end of the intermediate shaft 23, which protrudes to the rear left side of the crankcase 15.

[0051] Within the transmission housing 17, near the transmission 21, is a shift mechanism 25 that switches the gear pairs of the transmission gear set 24. The shift mechanism 25 causes multiple shift forks 32a to operate according to the pattern of guide grooves formed on the outer periphery of the shift drum 32 by rotating a hollow cylindrical shift drum 32 parallel to the two shafts 22 and 23, thereby switching the gear pairs used for power transmission between the two shafts 22 and 23 in the transmission gear set 24.

[0052] Here, the motorized two-wheeled vehicle 1 employs a so-called semi-automatic transmission system (automatic clutch transmission system) in which the driver only performs the gear shifting operation of the transmission 21 (foot operation of the shift pedal (not shown)) and the disengagement operation of the clutch device 26 is automatically performed by electronic control according to the operation of the shift pedal.

[0053] <Transmission System>

[0054] like Figure 3 As shown, the aforementioned transmission system 30 includes a clutch actuator 50, an ECU 40 (Electronic Control Unit), various sensors 41a to 41f, and various devices 47, 48, and 50.

[0055] ECU 40 detects the gear position of the transmission stage based on the acceleration sensor 41a that detects the behavior of the vehicle body, the gear position sensor 41b that detects the rotation angle of the shift drum 32, and the shift shaft 31 (see reference) of the shift mechanism 25. Figure 2The system uses various vehicle status detection information, such as the shift load sensor 41c (e.g., torque sensor) for input operating torque, the throttle opening sensor 41d for detecting throttle opening, the vehicle speed sensor 41e for detecting vehicle speed, and the engine speed sensor 41f for detecting engine speed, to control the operation of the ignition device 47 and the fuel injection device 48, and to control the operation of the clutch actuator 50. The vehicle speed sensor 41e can be a wheel speed sensor or a rotation speed sensor of the output shaft of the power unit PU.

[0056] The motorized two-wheeled vehicle 1 is equipped with a drive-by-wire engine control system (throttle-by-wire) that electrically coordinates the operation of engine auxiliary components such as the throttle zone with the operating components such as the throttle control lever operated by the driver.

[0057] Refer to together Figure 5 , Figure 6 The clutch actuator 50 controls the operating torque applied to the release shaft 53 to disengage or engage the clutch device 26. The clutch actuator 50 includes an electric motor 52 (hereinafter simply referred to as motor 52) as a drive source and a reduction mechanism 51 that transmits the driving force of the motor 52 to the release shaft 53. The reduction mechanism 51 includes a first reduction shaft 57 and a second reduction shaft 58, and a first rotation angle sensor 57d and a second rotation angle sensor 58d are provided on each of the shafts 57 and 58 to detect the rotation angle.

[0058] The ECU 40 calculates the current value supplied to the motor 52 to disengage or engage the clutch device 26 based on a pre-set calculation program. The supply current to the motor 52 is determined in relation to the torque output by the motor 52. The target torque of the motor 52 is proportional to the operating torque applied to the release shaft 53 (the release shaft torque described later). The current value supplied to the motor 52 is detected by a current sensor 40b included in the ECU 40. The clutch actuator 50 is controlled based on changes in this detected value. The clutch actuator 50 will be described in detail later.

[0059] Clutch mechanism

[0060] like Figure 2 , Figure 11As shown, the clutch device 26 of the embodiment is a multi-plate clutch formed by stacking multiple clutch plates 35 in the axial direction, and is a wet clutch disposed in the oil chamber within the right cover 17a. The clutch device 26 includes: a clutch outer ring 33, which is always driven by transmitting rotational power from the crankshaft 14; a clutch center ring 34, which is disposed within the clutch outer ring 33 and supported on the main shaft 22 in a manner that allows it to rotate integrally; and multiple clutch plates 35, which are stacked between the clutch outer ring 33 and the clutch center ring 34 and are frictionally engaged.

[0061] A pressure plate 36, approximately the same diameter as the clutch plates 35, is positioned to the right (outer side in the vehicle width direction) of the stacked clutch plates 35. The pressure plate 36 is subjected to an elastic load from the clutch spring 37 and is forced to the left, causing the stacked clutch plates 35 to press against each other (friction engagement). This puts the clutch assembly 26 into an engaged state capable of transmitting power. The clutch assembly 26 is a normally closed clutch that is engaged when there is no external input.

[0062] The release of the press-fit (friction engagement) is achieved by the operation of the release mechanism 38 inside the right cover 17a. The operation of the release mechanism 38 is achieved by at least one of the occupant's operation of the clutch release lever 4b and the application of torque based on the clutch actuator 50.

[0063] <Separation Mechanism>

[0064] like Figure 2 , Figure 11 As shown, the separation mechanism 38 includes: a clutch shaft 39 held within the right side portion of the main shaft 22, capable of axial reciprocating movement; and a separation shaft 53, axially orthogonal to the clutch shaft 39 and held within the outer side portion of the right cover 17a, capable of rotating about its axis. Line C3 in the figure represents the central axis of the separation shaft 53 extending in the vertical direction. In axial view (side view of the vehicle) of the main shaft 22, the separation shaft 53 is axially tilted rearward relative to the vertical direction, moving towards the uppermost and rearmost side (see reference). Figure 1 The upper part of the release shaft 53 protrudes outward from the right cover 17a, and the driven clutch release lever 54 is mounted on the upper part of the release shaft 53 in a manner that allows it to rotate integrally. The driven clutch release lever 54 is connected to the clutch release lever 4b via an operating cable 54c.

[0065] An eccentric cam portion 38a is provided on the lower part of the release shaft 53, located inside the right cover 17a. The eccentric cam portion 38a engages with the right end of the clutch shaft 39. The release shaft 53 rotates about its axis, thereby causing the clutch shaft 39 to move to the right under the action of the eccentric cam portion 38a. The clutch shaft 39 is configured to reciprocate integrally with the pressure plate 36 of the clutch device 26. Therefore, when the clutch shaft 39 moves to the right, the pressure plate 36 moves to the right (lifts) against the force of the clutch spring 37, disengaging the frictional engagement of the stacked clutch plates 35. As a result, the normally closed clutch device 26 is in an open state where it cannot transmit power.

[0066] It should be noted that the separation mechanism 38 is not limited to an eccentric cam mechanism, but can also be a mechanism with rack and pinion, feed screw, etc. The mechanism connecting the clutch release lever 4b and the driven clutch release lever 54 is not limited to the operating cable 54c, but can also be a mechanism with rod, connecting rod, etc.

[0067] <Clutch Control Mode>

[0068] like Figure 4 As shown, the clutch control device 40A of this embodiment has three clutch control modes. The clutch control mode is selected based on the clutch control mode switching switch 49 and the clutch disengagement lever 4b (both refer to...). Figure 3 The system can switch appropriately between three modes: automatic mode M1 for automatic control, manual mode M2 ​​for manual operation, and manual intervention mode M3 for temporary manual operation. It should be noted that the object including both manual mode M2 ​​and manual intervention mode M3 is referred to as the manual system M2A.

[0069] Automatic mode M1 is a mode that controls the clutch device 26 by calculating the appropriate clutch capacity for the driving state through automatic start / transmission control. Manual mode M2 ​​is a mode that controls the clutch device 26 by calculating the clutch capacity based on the clutch operation instruction given by the passenger. Manual intervention mode M3 is a temporary manual operation mode that receives the clutch operation instruction from the passenger in automatic mode M1 and controls the clutch device 26 by calculating the clutch capacity based on the clutch operation instruction. It should be noted that it can also be set so that, in manual intervention mode M3, for example, if the state of the passenger stopping the operation of the clutch release lever 4b (fully released state) continues for a specified time, the system returns to automatic mode M1.

[0070] For example, when the system starts, the clutch control device 40A starts control from the clutch engaged state (engaged state) via automatic mode M1. Furthermore, the clutch control device 40A is set to return to the clutch engaged state via automatic mode M1 when the engine 13 stops (when the system is off). In the normally closed clutch device 26, when the clutch is engaged, the power supply to the motor 52 of the clutch actuator 50 may be absent. On the other hand, when the clutch device 26 is in the clutch disengaged state (disengaged state), the power supply to the motor 52 is maintained.

[0071] The automatic mode M1 is based on automatic clutch control, enabling the motorized two-wheeler 1 to move without lever operation. In automatic mode M1, the clutch capacity is controlled based on throttle opening, engine speed, vehicle speed, and shift sensor output. This allows the motorized two-wheeler 1 to start without engine stalling when only the throttle is operated, and to shift gears only when shifting gears. Furthermore, in automatic mode M1, by having the occupant hold the clutch release lever 4b, the clutch mechanism 26 can be disengaged at will by switching to manual intervention mode M3.

[0072] On the other hand, in manual mode M2, the clutch capacity can be controlled by lever operation performed by the occupant (i.e., the clutch device 26 can be disengaged or engaged). Automatic mode M1 and manual mode M2 ​​can be achieved, for example, when the motorized two-wheeled vehicle 1 is parked and the transmission 21 is in neutral, by operating the clutch control mode switch 49 (see reference). Figure 3 The clutch control device 40A can be switched between these modes. It should be noted that the clutch control device 40A may also have an indicator that shows the manual mode when switching to the manual system M2A (manual mode M2 ​​or manual intervention mode M3).

[0073] The basis of manual mode M2 ​​lies in the ability to control the clutch capacity manually, based on the operating angle of the clutch release lever 4b (and even the operating angle of the release shaft 53). This allows for control of the clutch mechanism 26's engagement or disengagement while ensuring the occupant's intentions are met. It should be noted that even in manual mode M2, clutch control automatically engages when a gear shift is performed without clutch operation. Hereinafter, the operating angle of the release shaft 53 will be referred to as the release shaft operating angle.

[0074] In automatic mode M1, the clutch device 26 is automatically disengaged by the clutch actuator 50, but by performing manual clutch operation on the clutch release lever 4b, manual operation can be temporarily intervened in the automatic control of the clutch device 26 (manual intervention mode M3).

[0075] Refer to together Figure 2 The clutch release lever 4b is connected to the driven clutch release lever 54 mounted on the release shaft 53 of the clutch assembly 26 via an operating cable 54c. The driven clutch release lever 54 is mounted on the upper end of the right-facing cover 17a in the release shaft 53 in a manner that allows it to rotatably as a single unit.

[0076] Additionally, for example, the clutch control mode switching switch 49 is provided on the handlebar switch mounted on the steering handlebar 4a (see reference). Figure 3 Therefore, passengers can easily switch clutch control modes during normal driving.

[0077] Clutch Actuator

[0078] like Figure 1 As shown, a clutch actuator 50 is installed on the upper rear part of the right cover 17a on the right side of the crankcase 15.

[0079] Refer to together Figure 5 , Figure 6 The clutch actuator 50 includes a motor 52 and a reduction mechanism 51 that transmits the driving force of the motor 52 to the release shaft 53.

[0080] Motor 52 is, for example, a DC motor, and is configured such that its axis is parallel to the separation shaft 53. Motor 52 is configured such that the drive shaft 55 protrudes upward.

[0081] In this embodiment, a single clutch actuator 50 may include multiple (two) motors 52. Hereinafter, the motor 52 located at the front of the clutch actuator 50 will be referred to as the first motor 521, and the motor 52 located at the rear of the vehicle and inside the vehicle width direction relative to the first motor 521 will be referred to as the second motor 522. In the figures, lines C01 and C02 represent the central axes (drive axes) of each motor 521 and 522, respectively. For ease of explanation, the two motors 521 and 522 are sometimes collectively referred to as motor 52. Additionally, the two axes C01 and C02 are sometimes collectively referred to as axis C0.

[0082] The reduction mechanism 51 reduces the rotational power output from the motor 52 and transmits it to the separation shaft 53. The reduction mechanism 51 has, for example, a gear train axially parallel to the separation shaft 53. The reduction mechanism 51 includes a drive gear 55a integrally mounted on the drive shaft 55 of each motor 521, 522, a first reduction gear 57a meshing with each drive gear 55a, a first minor diameter gear 57b coaxial with the first reduction gear 57a, a second reduction gear 58a meshing with the first minor diameter gear 57b, a second minor diameter gear 58b coaxial with the second reduction gear 58a, a driven gear 63a meshing with the second minor diameter gear 58b, and a gearbox 59 housing each gear.

[0083] The first reduction gear 57a and the first minor diameter gear 57b are rotatably supported on the first support shaft 57c, forming the first reduction shaft 57. The second reduction gear 58a and the second minor diameter gear 58b are rotatably supported on the second support shaft 58c, forming the second reduction shaft 58. The first support shaft 57c and the second support shaft 58c are rotatably supported on the gearbox 59. The second reduction gear 58a is a sector gear at the center of the second support shaft 58c, extending outwards in the front of the second support shaft 58c and in the vehicle width direction. In the figure, line C1 represents the central axis of the first reduction shaft 57, and line C2 represents the central axis of the second reduction shaft 58.

[0084] The driven gear 63a is supported on the separation shaft 53 in a manner that allows it to rotate integrally. The driven gear 63a is a sector gear at the center of the separation shaft 53, and is arranged to extend forward from the separation shaft 53. The rotation angle of the gear on the downstream side of the reduction mechanism 51 is small, which allows the second reduction gear 58a and the driven gear 63a to be sector gears with small rotation angles.

[0085] As a result, miniaturization of the reduction mechanism 51 and even the clutch actuator 50 can be achieved. That is, when a large-diameter reduction gear is provided in order to obtain a reduction ratio, by cutting off the part of the reduction gear outside the meshing range to make it fan-shaped, it is possible to suppress the extension of the reduction mechanism 51, in particular, outward in the vehicle width direction, and to achieve weight reduction of the reduction mechanism 51.

[0086] According to the above structure, the motor 52 and the release shaft 53 can be continuously linked via the reduction mechanism 51. Thus, a system is formed in which the clutch device 26 is directly disengaged or engaged via the clutch actuator 50.

[0087] Each gear is a flat spur gear with reduced axial thickness, and the gearbox 59 is also formed in a flat shape with reduced axial thickness. As a result, the reduction mechanism 51 is not easily visible when viewed from the side of the vehicle. A first rotation angle sensor 57d and a second rotation angle sensor 58d are provided on the upper surface of the gearbox 59, which are connected to one end of the first reduction shaft 57 and the second reduction shaft 58, respectively, to detect their rotation angle.

[0088] The motor 52 is configured to protrude downward from the front of the gearbox 59. As a result, the motor 52 can be configured to avoid the bulge 17b covering the clutch device 26 in the right cover 17a, and the extension of the clutch actuator 50 outward in the vehicle width direction can be suppressed.

[0089] Reference Figure 1 , Figure 11The right cover 17a, when viewed from the side of the vehicle, has a circular area coaxial with the clutch device 26, which bulges outward in the vehicle width direction. A cover recess 17c is formed in the rear-upward portion of the bulge 17b, where the outer side faces inward in the vehicle width direction relative to the remaining portion. The lower end of the cover recess 17c is a stepped portion 17d, which causes the outer surface of the bulge 17b to change in a stepped shape. The upper part of the release shaft 53 protrudes obliquely upward and rearward from the stepped portion 17d.

[0090] The driving force of the motor 52 is reduced between the drive gear 55a and the first reduction gear 57a, and further reduced between the first minor diameter gear 57b and the second reduction gear 58a, and then reduced between the second minor diameter gear 58b and the driven gear 63a before being transmitted to the separation shaft 53.

[0091] <Separation Shaft>

[0092] like Figures 6-8 As shown, the separation shaft 53 is divided into multiple elements so that it can rotate to receive inputs from the clutch actuator 50 and inputs based on the occupant's operation.

[0093] The separation shaft 53 includes an upper separation shaft 61 constituting the upper part, a lower separation shaft 62 constituting the lower part, and an intermediate separation shaft 63 arranged across the lower end of the upper separation shaft 61 and the upper end of the lower separation shaft 62.

[0094] The upper part of the separation shaft 61 is cylindrical and rotatably supported on the upper boss 59b of the gearbox 59. The upper end of the upper part of the separation shaft 61 protrudes outward from the gearbox 59, and the driven clutch release lever 54 is supported on the upper end in a manner that allows it to rotate integrally. A return spring 54s is installed on the driven clutch release lever 54, which applies a force to the driven clutch release lever 54 in the opposite direction to the rotation (rotation in the clutch disengagement direction) generated by the operation of the clutch release lever 4b.

[0095] The lower separation shaft 62 is cylindrical and rotatably supported on the inside of the right cover 17a. An eccentric cam portion 38a for the separation mechanism 38 is formed in the lower part of the lower separation shaft 62 facing the gearbox 59. A lower return spring 62s is installed at the lower end of the lower separation shaft 62, which applies a force to the lower separation shaft 62 in the opposite direction to the clutch disengagement direction of rotation.

[0096] A manually operated side cam 61b with a fan-shaped cross-section and extending axially is provided at the lower end of the upper part of the shaft 61.

[0097] At the upper end of the lower part of the shaft 62, a clutch-side cam 62b with a fan-shaped cross section and extending axially is provided within a range that avoids the manual operation side cam 61b in the circumferential or axial direction.

[0098] The lower end of the upper part of the off-axis 61 (manual operation side cam 61b) and the upper end of the lower part of the off-axis 62 (clutch side cam 62b) are circumferentially separated from each other and axially overlapped (or axially separated from each other and circumferentially overlapped). Therefore, the lower part of the off-axis 62 can be rotated by pressing the circumferential side 61b1 of the manual operation side cam 61b against the circumferential side 62b2 of the clutch side cam 62b (see reference). Figure 9B , Figure 10B ).

[0099] The other circumferential side 61b2 of the manual operation side cam 61b and the circumferential side 62b1 of the clutch side cam 62b are separated from each other circumferentially or axially. Therefore, when there is input from the clutch actuator 50 on the clutch side cam 62b, the lower off-axis 62 can rotate independently from the upper off-axis 61 (see reference). Figure 9A , Figure 10A ).

[0100] The intermediate split shaft 63 is cylindrical in shape, allowing the lower end of the upper split shaft 61 and the upper end of the lower split shaft 62 (upper and lower shaft engagement portion) to pass through. The driven gear 63a is supported on the intermediate split shaft 63 in a manner that allows it to rotate integrally. The intermediate split shaft 63 is provided with a control operation side cam 63b with a fan-shaped cross-section that extends axially.

[0101] The control operation side cam 63b of the intermediate separation shaft 63 and the clutch side cam 62b of the lower separation shaft 62 are circumferentially separated from each other and overlap in axial position (or axially separated from each other and overlap in circumferential position). Thus, the lower separation shaft 62 can be rotated by pressing the other circumferential side 62b2 of the clutch side cam 62b with the circumferential side 63b1 of the control operation side cam 63b.

[0102] Furthermore, the control operation side cam 63b is configured to axially or radially avoid the manual operation side cam 61b of the upper part of the separation shaft 61. Therefore, when input from the clutch actuator 50 is transmitted to the clutch side cam 62b, the lower part of the separation shaft 62 can rotate independently from the upper part of the separation shaft 61. Additionally, in the presence of manual operation, the upper part of the separation shaft 61 can rotate independently from the intermediate separation shaft 63 on the control side.

[0103] The other circumferential side 63b2 of the control operation side cam 63b and the circumferential side 62b1 of the clutch side cam 62b are separated from each other in the circumferential direction. Thus, when there is input from the manual operation side cam 63b on the clutch side cam 62b, the lower part of the off-shaft 62 can rotate independently from the intermediate off-shaft 63.

[0104] Reference Figure 11 The clutch actuator 50 keeps the upper release shaft 61 and the intermediate release shaft 63 rotatable via the gearbox 59. The clutch actuator 50 includes the upper release shaft 61 and the intermediate release shaft 63 as an integral actuator unit 50A.

[0105] The lower part of the shaft 62 is rotatably held in the right cover 17a. The stepped portion 17d of the recess 17c in the right cover 17a has an opening 17e for the upper end of the lower part of the shaft 62 to protrude, and also provides a fastening connection portion 17f for the gearbox 59. The opposing portion in the gearbox 59, opposite the stepped portion 17d of the recess 17c, has an opening 59c that allows the upper end of the lower part of the shaft 62 to face into the gearbox 59.

[0106] In the above structure, when the actuator unit 50A is installed on the right cover 17a, the upper separation shaft 61, the middle separation shaft 63 and the lower separation shaft 62 are connected to each other to form a straight separation shaft 53.

[0107] The power unit PU of the embodiment can be configured as follows: for a manual clutch-type power unit where the clutch device 26 is disengaged or engaged by the driver rather than through electrical control, the right cover 17a and release shaft 53 are replaced, and an actuator unit 50A is added. Therefore, the actuator unit 50A can be installed even for power units of different models, and the actuator unit 50A can be shared among multiple models, making it easy to construct a semi-automatic transmission system (automatic clutch-type transmission system).

[0108] Clutch Control

[0109] Next, refer to Figure 12 The line diagram is used to illustrate the clutch control implementation method. Figure 12 The line graph visualizes the clutch characteristics in the automatic mode M1. Figure 12 In the line graph, the vertical axis represents the torque (Nm) applied to the release shaft 53 and the clutch capacity (%), and the horizontal axis represents the working angle (deg) of the release shaft 53.

[0110] The torque generated on the release shaft 53 is equivalent to the following torque value, which is calculated by multiplying the torque value obtained based on the supply current value supplied to the motor 52 (which is related to the torque generated by the motor 52) by the reduction ratio of the reduction mechanism 51. Hereinafter, the torque of the release shaft 53 will be referred to as the release shaft torque. The relationship between the release shaft operating angle and the release shaft torque is represented by line L11 in the line graph. The relationship between the release shaft operating angle and the clutch capacity is represented by line L12 in the line graph. Line L11 also represents the output value (reference output value) of the clutch actuator 50 when the clutch device 26 is disengaged or engaged in a state where manual operation is not involved.

[0111] In the automatic mode M1 of the normally closed clutch, when the release shaft torque (motor output) is "0", there is no operational input (input to the disengagement side) to the clutch device 26, and the clutch capacity becomes 100%. That is, the clutch device 26 remains engaged. This state is equivalent to... Figure 12 Region A of the transverse shaft. Region A is the clearance region of the driven clutch release lever 54. In region A, there is no motor output, and the release shaft torque is shifted at "0". In region A, the clutch assembly 26 is not engaged, and the clutch capacity is shifted at 100%.

[0112] Refer to together Figure 8 In region A, the circumferential side 61b1 of the manual operation side cam 61b of the release shaft 53 does not press against the other circumferential side 62b2 of the clutch side cam 62b, but instead separates from the clutch side cam 62b under the force of the return spring 54s. Figure 8 (As shown by the dashed line). In region A, the driven clutch release lever 54 is in a clearance state that allows the manual operation side cam 61b to approach or move away from the clutch side cam 62b at an angle A1 as shown in the figure. For example, in region A, one circumferential side 63b1 of the control operation side cam 63b is in contact with the other circumferential side 62b2 of the clutch side cam 62b.

[0113] Reference Figure 12 When the working angle of the release shaft increases and exceeds the clearance region A, the working angle of the release shaft changes towards the semi-engaged region B.

[0114] Refer to together Figure 9A In the semi-engaged region B, the control operation side cam 63b presses against the clutch side cam 62b, causing the lower part of the off-shaft 62 to rotate. When the release shaft torque increases, the release mechanism 38 causes the clutch device 26 to engage to reduce the clutch capacity. That is, the clutch device 26 is in a semi-engaged state capable of partial power transmission. Figure 12The symbol SP indicates the starting position (operation start position) for switching from the clearance region A to the semi-clutch region B. In the semi-clutch region B, if manual operation is engaged, the manual operation side cam 61b abuts against the clutch side cam 62b and, in cooperation with the control operation side cam 63b, rotates the lower part of the off-axis 62 (see reference). Figure 9B ).

[0115] When the release shaft operating angle exceeds the contact point TP, which is the end of the half-clutch region B, the increase in release shaft torque becomes gradual compared to region B. The region after the contact point TP in the release shaft operating angle becomes the clutch disengagement region C, where the clutch capacity is maintained at a state equivalent to "0". The clutch disengagement region C is, for example, a working margin region for operating the release shaft 53, etc., to its mechanical working limit position. In the clutch disengagement region C, the release shaft torque increases slightly. The amount of this increase corresponds to the increase in clutch spring load associated with the movement of the disengagement component of the clutch device 26. Figure 12 The symbol EP in the middle indicates the fully disengaged position, which is the end of the clutch disengagement zone C.

[0116] For example, a standby position DP is set in the middle of the clutch disengagement region C. At the standby position DP, a slightly higher release shaft torque than the contact point TP at which the clutch device 26 begins to engage is applied. At the contact point TP, there may be slight torque transmission due to operational errors, but by applying the release shaft torque until the standby position DP, the torque transmission of the clutch device 26 can be completely cut off. Furthermore, at the standby position DP, by applying a slightly lower release shaft torque than the fully disengaged position EP, ineffectiveness of the clutch device 26 can be eliminated. That is, at the standby position DP, loosening of various parts of the clutch device 26 or elimination of working reaction forces can be achieved, thereby improving the operational responsiveness of the clutch device 26 during engagement.

[0117] It should be noted that when the clutch device 26 is working from the engaged state to the disengaged state, the point where the torque of the release shaft increases (the starting point of the half-clutch area B) is the working start position SP, and the point where the clutch device 26 is completely disengaged (the ending point of the half-clutch area B) is the contact point TP.

[0118] Conversely, when the clutch device 26 operates from the disengaged state to the engaged state, the point at which the clutch device 26 begins to engage is the contact point TP, and the point at which the clutch device 26 is fully engaged is the working start position SP.

[0119] Reference Figure 13 In the semi-clutch region B, the drive of motor 52 is controlled based on the lift-off load.

[0120] In the above control process, firstly, the clutch spring load is preset based on the elastic force of the clutch spring 37. Next, the disengagement load (operating load resisting the clutch spring load) acting on the clutch assembly 26 is estimated based on the release shaft torque. Then, the load obtained by subtracting the disengagement load from the clutch spring load is taken as the actual clutch clamping load acting on the clutch assembly 26.

[0121] The clutch capacity is determined based on "clutch clamping load / clutch spring load". The power supplied to the motor 52 is controlled in a way that makes the clutch capacity a target value, thereby controlling the release shaft torque and even lifting the load. The motor current value and lever operating angle at the working start position SP and contact point TP are preset to predetermined values, or set through learning control when the power to the motorized two-wheeled vehicle 1 is turned on or off, as described later.

[0122] As an example of a sensing structure, there is a structure in which a current sensor 40b is installed in the motor control unit (ECU40), and its detected value is converted into motor torque, and then into release shaft torque (clutch operating torque).

[0123] like Figure 13 As shown, in the semi-clutch region B, if there is intervention of the clutch release lever 4b (manual operation), the measured value of the release shaft torque will decrease relative to the preset correlation line L11 of the release shaft torque (see part F in the figure). At this time, if the decrease in the release shaft torque exceeds the preset threshold d1, it is determined that there is intervention of manual operation, and the control switches to the preset manual operation intervention.

[0124] In manual operation intervention control, for example, from the detection of manual operation intervention until the increase in the release shaft operating angle reaches a predetermined angle or more, feedback control is performed on the motor 52 to maintain the release shaft torque at a reduced threshold d1 and torque d2. In current control at this time, a current limit corresponding to the angle is set after the contact point TP, and the motor output is approximately 0 in the middle. Since the load is very low at this time, it is determined that manual intervention has been performed. This suppresses the discomfort caused by the sudden disappearance of torque from the motor 52 after operating the clutch release lever 4b. After the increase in the release shaft operating angle reaches a predetermined angle or more, the release shaft torque is gradually reduced (see part G in the diagram), thereby suppressing the aforementioned discomfort while also suppressing power consumption caused by continuous drive of the motor 52.

[0125] In the clutch disengagement region C, the drive of motor 52 is controlled based on the lever position (angle).

[0126] As mentioned earlier, in the clutch disengagement region C, the increase in release shaft torque associated with the disengagement of clutch device 26 is minimal. Therefore, in the clutch disengagement region C, the power supplied to motor 52 is controlled based on the release shaft operating angle. Consequently, the amount of disengagement of clutch device 26 can be controlled more precisely after the contact point TP where clutch device 26 begins to engage.

[0127] As an example of a sensing structure, the following structure is provided: a first rotation angle sensor 57d and a second rotation angle sensor 58d are respectively provided on the first reduction shaft 57 and the second reduction shaft 58, and their detection values ​​are converted into the working angle of the release shaft (clutch operating angle). The first rotation angle sensor 57d and the second rotation angle sensor 58d are provided as a pair to prevent failure, but it is also possible to have only one of them.

[0128] like Figure 13 As shown, in the clutch disengagement region C, if the clutch release lever 4b is operated (manually), the measured value of the release shaft torque will decrease relative to the preset release shaft torque correlation line L11 (see part H in the figure).

[0129] Refer to together Figure 10A For example, in automatic mode M1, the torque applied by the control operation side cam 63b to the clutch side cam 62b is capped at the torque until the idle position DP is reached. The torque of the clutch side cam 62b over the idle position DP until the fully disengaged position EP is as follows: due to the manual operation intervention of engaging the clutch disengagement lever 4b, the torque over the idle position DP is applied from the manual operation side cam 61b to the clutch side cam 62b (see reference). Figure 10B At this point, the control operation side cam 63b disengages from the clutch side cam 62b, and the motor output is essentially zero.

[0130] Even when approaching the standby position DP, if the clutch disengagement zone C, where the working angle of the release shaft has crossed the contact point TP, is within the clutch disengagement zone C, the measured value of the release shaft torque will be practically zero due to manual intervention. Therefore, within the clutch disengagement zone C, if the measured value of the release shaft torque changes to a practically zero range, it is determined that manual intervention has occurred, and the system switches to the pre-defined manual intervention control.

[0131] In manual operation intervention control, for example, from the moment manual operation intervention is detected until the increase in the release shaft operating angle reaches a predetermined angle or higher, the motor output is maintained by keeping the release shaft operating angle in a substantially disengaged clutch position, i.e., contact point TP. Therefore, even if the clutch release lever 4b is suddenly released after manual operation intervention, engine stalling can be prevented.

[0132] In this way, load (current) control and position (angle) control are used separately according to the condition of the clutch device 26, thereby enabling more precise clutch control (optimal control corresponding to the condition and characteristics of the clutch device 26).

[0133] In the implementation, the working angle of the release shaft (the rotation angle of the gear shaft of the reduction mechanism 51) is detected. In the region up to the preset (or learned) contact point TP (the half-clutch region B), the control becomes the weight of increasing the current value. In the region after the contact point TP (the clutch disengagement region C), the control becomes the weight of increasing the working angle.

[0134] Furthermore, in this embodiment, the change in the current value (converted to torque value) of the motor 52 relative to the working angle of the release shaft is learned (updated) at predetermined times, and a target value corresponding to the condition of the clutch device 26 is set. Feedback control of the motor 52's drive is then performed based on this target value and the detection value of the current sensor 40b of the ECU 40.

[0135] <Changes in driving mode>

[0136] Figure 14 The timeline shows the process of a motorized two-wheeled vehicle 1 traveling on flat ground in cruise mode (cruise mode, constant speed driving mode) and then returning to flat ground after going downhill.

[0137] During the time range t0 prior to timing t1 in the diagram, the motorized two-wheeled vehicle 1 travels on flat ground on a slope. In this implementation, "flat ground" refers to a location where the road surface inclination is less than the specified angle θr described later. At this time, under specified driving conditions (e.g., a vehicle speed V1 above a specified speed), the driver activates the cruise control switch 45 (see reference t0). Figure 3 By operating the throttle, the motorized two-wheeled vehicle 1 switches to cruise mode. In cruise mode, the engine and auxiliary equipment are controlled to maintain a constant vehicle speed V1 at the time of the switch operation. In cruise mode, the vehicle speed V1 can be maintained without driver intervention. In cruise mode, the vehicle speed V1 can be increased or decreased by operating the speed adjustment switch (not shown). In cruise mode, even if the driver takes their hand off the throttle control lever, the vehicle can continue to travel at a constant speed of V1.

[0138] In cruise mode, unless there is a major reason that particularly hinders the constant speed driving of the motorized two-wheeled vehicle 1, the engine speed Ne, throttle control handle opening Gθth, throttle zone (valve) opening Bθth, and clutch capacity Cap will be constantly shifted.

[0139] In cruise mode, for example based on acceleration sensor 41a (reference) Figure 3When the ECU 40 detects that the motorized two-wheeled vehicle 1 has reached a downhill slope (time t1 in the figure), the motorized two-wheeled vehicle 1 switches to coasting mode (inertial travel mode). The switch to coasting mode occurs, for example, when the acceleration sensor 41a detects a descent angle θr or greater (e.g., 10 degrees or greater). The switch can also be implemented, for example, when the acceleration sensor 41a continuously detects a descent angle θr or greater for a specified period of time. In coasting mode, the clutch device 26 is disengaged, creating an idle state (inertial travel state) where engine braking is ineffective. In coasting mode, for example, the engine 13 is brought to a stop, eliminating fuel consumption during inertial travel and improving fuel efficiency. The engine 13 can also be brought to idle in coasting mode. A switch that allows selection of whether to switch to coasting mode may also be provided.

[0140] In coasting mode, the clutch capacity Cap is reduced from the capacity Cap1 in cruise mode (e.g., 100% when clutch device 26 is engaged). In coasting mode, the clutch capacity Cap is reduced to the capacity Cap2 used in coasting mode (e.g., 0% when clutch device 26 is disengaged).

[0141] In coasting mode, the throttle opening Bθth is reduced from the cruising opening Bθ1, corresponding to the change in clutch capacity Cap. In coasting mode, the throttle opening Bθth is reduced to the coasting mode opening Bθ2 (for example, to the angle of full throttle closure).

[0142] Therefore, in coasting mode, the engine speed Ne is reduced from the cruising speed Ne1. In coasting mode, the engine speed Ne is reduced to the coasting speed Ne2 (e.g., 0 rpm). That is, in coasting mode, the engine 13 stops.

[0143] It should be noted that in coasting mode, the throttle opening Gθth can remain unchanged if you only switch to coasting mode.

[0144] In addition, in coasting mode, the clutch device 26 is disengaged from the cruise mode at a constant speed V1, and the vehicle continues to travel downhill due to inertia, thereby the vehicle speed V increases slowly within a range less than the threshold V2.

[0145] In coasting mode, for example, when the ECU 40 detects, based on the detection information from the acceleration sensor 41a, that the inclination of the current downhill slope has decreased (becoming less than the specified angle θr) (timing t2 in the figure), the motorized two-wheeled vehicle 1 ends the coasting mode. That is, the engine 13 restarts and the clutch device 26 re-engages. At this time, immediately after timing t2, within the time range t23 between timing t2 and t3 in the figure, the first matching control is performed. Before fully engaging the clutch device 26, the first matching control makes the engine speed Ne consistent with the cruising speed Ne1. The first matching control converges the engine speed Ne to the cruising speed Ne1, and simultaneously engages the clutch device 26 within the semi-clutch range.

[0146] Following the first matching control, a second matching control is performed within the time range t34 between timings t3 and t4 in the diagram. The second matching control is a control that, after the engine speed Ne converges to the speed Ne1, matches the transmission capacity transmitted to the transmission 21 side (so that the vehicle speed V smoothly converges to the target vehicle speed V1 during cruising).

[0147] In the second matching control, as the slope of the downhill becomes gentler, the clutch capacity Cap gradually increases. At the end of the downhill detection, the clutch device 26 becomes the capacity Cap1 that is engaged.

[0148] The second matching control provides feedback control of the clutch capacity Cap to make the current vehicle speed V match the set vehicle speed V1 during cruising, thereby causing the clutch device 26 to transition to the engaged state. The time range t34 of the second matching control is set longer than the time range t23 of the first matching control.

[0149] The above steps complete the transition from coasting mode to engine driving mode (cruise mode).

[0150] Figure 15 The time graph represents relative to Figure 14 The implementation method includes a variation of the response to the situation where the vehicle speed V between the timings t11 and t12 in the coasting mode becomes above the threshold V2.

[0151] exist Figure 15 When the vehicle speed V increases to a level exceeding the threshold V2, the ECU 40 temporarily increases the clutch capacity Cap to control engine braking. Specifically, the clutch device 26 is temporarily engaged, increasing the engine speed Ne via input from the rear wheel 12. This generates engine braking, reducing the vehicle speed. The target increase in clutch capacity Cap can be the fully engaged capacity Cap1 of the clutch device 26, but it can be any value sufficient to achieve engine braking, or even lower than Cap1.

[0152] Figure 16 The time graph represents relative to Figure 14 The implementation includes a variation of the response to a situation where the driver performs a braking operation between timings t13 and t14 in the coasting mode.

[0153] exist Figure 16 In the middle, when the driver performs the braking operation (when the brake switch is on), and Figure 15 Similarly, ECU40 temporarily increases the clutch capacity Cap to control engine braking. That is, it temporarily engages the clutch mechanism 26, increasing the engine speed Ne through input from the rear wheel 12. This generates engine braking, which, in conjunction with driver-operated brake activation, reduces vehicle speed. It should be noted that the braking system of the motorized two-wheeled vehicle 1 can be a drive-by-wire system that electrically coordinates the brake actuators and brake devices, providing automatic brake assist. Alternatively, brake control and clutch control can be appropriately coordinated.

[0154] The following is for reference Figure 17 The flowchart illustrates the process of switching between coasting and cruise modes. This process is repeated at a predetermined cycle when the power is on (the main switch of the motorized two-wheeler 1 is on).

[0155] First, in step S1, it is determined whether the cruise control switch (cruise control switch 45) is turned on. If the result is yes in step S1 (cruise control switch is on), proceed to step S2. If the result is no in step S1 (cruise control switch is off), the process is temporarily terminated.

[0156] In step S2, it is determined whether the motorized two-wheeled vehicle 1 is traveling downhill on a slope with a gradient greater than a specified value. This determination is made, for example, by checking whether the detection value of the acceleration sensor 41a is greater than or equal to a predetermined threshold (the specified angle θr). If the result is yes (greater than the threshold) in step S2, the process proceeds to step S3. If the result is no (less than the threshold) in step S2, the process proceeds to step S8.

[0157] In step S3, the clutch capacity Cap is reduced to Cap2 (e.g., the clutch is disengaged). Additionally, in step S4, the engine speed Ne is reduced to Ne2 (e.g., the engine is stopped).

[0158] Then, in step S5, it is determined whether the current vehicle speed V has reached or exceeded a set value (the threshold V2). If it is yes (above the set value) in step S5, proceed to step S6. If it is no (below the set value) in step S5, the process is temporarily terminated.

[0159] In step S6, speed limit control is performed. This speed limit control includes not only control that increases the clutch capacity Cap, but also brake activation based on driver operation. Following step S6, in step S7, it is determined whether the vehicle speed V has become less than a set value. If yes (less than the set value) in step S7, the process temporarily ends. If no (exceeds the set value) in step S7, steps S6 and S7 are repeated until the speed falls below the set value.

[0160] If the result is no in step S1 (cruise control switch off) and no in step S2 (less than the threshold), proceed to step S8 to determine whether engine 13 is stopped. If the result is no in step S8 (engine not stopped), temporarily end the process. If the result is yes in step S8 (engine stopped), proceed to step S9 to start the engine, and proceed to step S10 to control the increase of clutch capacity, and temporarily end the process.

[0161] As described above, the clutch control device 40A in the above embodiment includes: a clutch device 26 that disconnects or 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 an ECU 40 that performs drive control on the clutch actuator 50. The motorized two-wheeled vehicle 1 equipped with the clutch control device 40A can implement a cruise mode that maintains a constant vehicle speed V. In the cruise mode, when it is detected that the vehicle is driving downhill, it can implement a coasting mode that reduces the clutch capacity Cap and puts the engine 13 into a stopped or idling state. When the motorized two-wheeled vehicle 1 detects that the downhill has ended in the coasting mode, it ends the coasting mode and returns to the cruise mode.

[0162] According to this structure, when the motorized two-wheeled vehicle 1 equipped with the clutch control device 40A reaches a downhill slope in cruise mode, the clutch capacity Cap decreases (becoming a clutch disengaged state) and switches to coasting mode. Upon completion of the downhill journey, the coasting mode ends and cruise mode resumes. Thus, by appropriately switching between coasting and cruise modes, fuel efficiency can be effectively improved while minimizing discomfort.

[0163] Furthermore, in the aforementioned clutch control device 40A, when the motorized two-wheeled vehicle 1 detects an increase in vehicle speed V in the coasting mode, which exceeds a threshold V2, the clutch capacity Cap is increased to generate engine braking.

[0164] According to this structure, when the vehicle speed V increases to a specified level due to a downhill slope in coasting mode, the clutch capacity Cap increases, thereby generating engine braking. Thus, speed adjustment can be easily performed through clutch control.

[0165] Furthermore, in the aforementioned clutch control device 40A, when the motorized two-wheeled vehicle 1 detects that the braking device is activated in the coasting mode, it increases the clutch capacity Cap to generate engine braking.

[0166] According to this structure, when the braking device is activated in coasting mode by the driver's operation, the clutch capacity Cap is increased in response to the operation of the braking device, thereby generating engine braking. Thus, braking assistance can be performed efficiently through clutch control.

[0167] In addition, in the aforementioned clutch control device 40A, when the motorized two-wheeled vehicle 1 finishes its downhill journey and ends the coasting mode to return to the cruise mode, it controls the clutch capacity Cap to make the current vehicle speed V consistent with the target vehicle speed of the cruise mode.

[0168] According to this structure, when the coasting mode ends and the vehicle returns to cruise mode at the end of the downhill slope, the current vehicle speed V is compared with the target speed of the cruise mode, and the clutch capacity Cap is controlled to quickly converge the current vehicle speed V to the target speed of the cruise mode. This allows for an efficient and smooth return to cruise mode while minimizing discomfort.

[0169] It should be noted that the present invention is not limited to the above embodiments. For example, the clutch operating component is not limited to the clutch release lever 4b, but can also be a clutch pedal or other various operating components. The clutch device is not limited to being configured between the engine and the transmission, but can also be configured between any output object other than the prime mover and the transmission. The prime mover is not limited to an internal combustion engine, but can also be an electric motor.

[0170] It is not limited to the above-described embodiments for use with automated clutch operation in motorcycles, but can also be used with motorcycles equipped with a so-called clutchless transmission. Although the so-called clutchless transmission is based on manual clutch operation, it can change gears by adjusting the driving force without manual clutch operation under specified conditions.

[0171] In addition, the term "straddle-type vehicle" includes all vehicles in which the driver straddles the vehicle body, including not only motorized two-wheeled vehicles (including bicycles and small motorcycles with prime movers), but also three-wheeled (including vehicles with two front wheels and one rear wheel in addition to vehicles with one front wheel and two rear wheels) or four-wheeled vehicles, and also vehicles in which the prime mover includes an electric motor.

[0172] Furthermore, the structure described above is an example of the present invention, and various modifications can be made without departing from the spirit of the present invention.

Claims

1. A vehicle (1) comprising a control unit (40) and a clutch device (26), the control unit (40) switching between a constant speed driving mode, which maintains a constant vehicle speed (V), and an inertial driving mode, which brings the prime mover (13) to a stop or idle state, the clutch device (26) disconnecting or connecting the power transmission between the prime mover (13) and the output object (21). The vehicle is characterized in that... When the control unit (40) detects that it is driving downhill in the constant speed driving mode, it controls the clutch device (26) to decrease the clutch capacity (Cap) and switch to the inertial driving mode. When the control unit (40) detects that the inclination of the downhill slope becomes less than a specified angle (θr) in the inertial driving mode, it performs a first matching control and a second matching control to end the inertial driving mode and controls the clutch device (26) to increase the clutch capacity (Cap) and switch back to the constant speed driving mode. After the first matching control is performed, the second matching control is performed. The first matching control is as follows: In the constant speed driving mode, the engine speed (Ne) of the prime mover (13) is converged to the speed (Ne1) during cruising, and at the same time, the clutch device (26) is engaged within the half-clutch range, so that the engine speed (Ne) of the prime mover (13) is consistent with the speed (Ne1) during cruising before the clutch device (26) is fully engaged in the constant speed driving mode. In the second matching control, as the downhill slope becomes gentler, the clutch capacity (Cap) is increased, and feedback control is performed to fully engage the clutch device (26) so that the current vehicle speed (V) matches the target vehicle speed (V1) of the constant speed driving mode. The time range of the second matching control is set to be longer than that of the first matching control.

2. The vehicle according to claim 1, characterized in that, When the control unit (40) detects that the vehicle speed (V) has increased to a threshold (V2) or higher in the inertial driving mode, it increases the clutch capacity (Cap) to generate engine braking.

3. The vehicle according to claim 1, characterized in that, When the control unit (40) detects that the braking device is working in the inertial driving mode, it increases the clutch capacity (Cap) according to the amount of operation of the braking device to generate engine braking.

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