JP7112594B2 - clutch controller - Google Patents

Description

The present invention relates to a clutch control device.
This application claims priority based on Japanese Patent Application No. 2019-080303 filed in Japan on April 19, 2019, the content of which is incorporated herein.

2. Description of the Related Art In recent straddle-type vehicles, an automatic clutch system has been proposed in which the connection/disengagement operation of a clutch device is automatically performed by electrical control. Some of such systems control the clutch operation according to the behavior of the vehicle body.
For example, Patent Literature 1 describes changing the half-clutch time according to the roll angle of the vehicle body.

Japanese Patent No. 5004915

By the way, Cited Document 1 describes that by controlling the clutch operation according to the roll angle of the vehicle body, the running feeling of the motorcycle is improved when turning or cornering. However, there is no description of controlling the clutch actuation according to the pitch angle of the vehicle body. Engine output control by TBW (Throttle By Wire) is known as control according to the pitch angle of the vehicle body during sudden acceleration, but further improvement in responsiveness is desired.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a clutch control device capable of automatically controlling the clutch, capable of controlling the behavior of the vehicle body in the pitch direction during acceleration of the vehicle with good responsiveness.

As means for solving the above problems, aspects of the present invention have the following configurations.
(1) A clutch control device according to an aspect of the present invention includes an engine, a transmission, a clutch device for connecting and disconnecting power transmission between the engine and the transmission, and driving the clutch device to increase the clutch capacity. A clutch actuator to be changed, a control section for calculating a target value of a control parameter for the clutch capacity, and vehicle body behavior detection means for detecting acceleration of a vehicle body in a longitudinal direction of the vehicle, wherein the control section detects the vehicle body behavior. The clutch capacity is controlled so that the acceleration in the longitudinal direction of the vehicle detected by means does not exceed a predetermined upper limit value.

(2) In the clutch control device described in (1) above, the vehicle body behavior detection means may be an acceleration sensor that detects the acceleration.

(3) In the clutch control device described in (1) or (2) above, the vehicle body behavior detection means also functions as vehicle body posture detection means for detecting the pitch angle of the vehicle body, and the control unit detects the vehicle body pitch angle. The upper limit value of the acceleration may be lowered when the pitch angle of the vehicle body detected by the behavior detection means exceeds a predetermined specified value.

(4) In the clutch control device according to any one of (1) to (3) above, even if the upper limit value of the acceleration is set to an acceleration value at which the ground contact load of the front wheels is equal to or less than a predetermined lower limit value, good.

(5) In the clutch control device according to any one of (1) to (4) above, the upper limit value of the acceleration is determined by a line segment connecting the rear wheel ground contact position and the predetermined center of gravity of the vehicle, and the road surface. , may be calculated based on the angle formed by .

(6) The clutch control device according to any one of (1) to (5) above includes a front wheel speed sensor that detects the rotational speed of the front wheels, and a rear wheel speed sensor that detects the rotational speed of the rear wheels. , wherein the control unit detects a difference between the rotational speeds of the front wheels and the rear wheels detected by the front wheel speed sensor and the rear wheel speed sensor, respectively, when the difference is equal to or greater than a predetermined specified value. , the clutch capacity may be reduced.

According to the clutch control device described above in (1) of the present invention, by controlling the clutch capacity so that the acceleration in the longitudinal direction of the vehicle does not exceed a predetermined upper limit value, the range in which wheelie of the vehicle body is suppressed (the The maximum acceleration can be achieved within the range where the behavior in the pitch direction is suppressed. In addition, since the vehicle body acceleration is controlled by controlling the clutch capacity, it is possible to realize acceleration control with higher response than acceleration control by engine output control.

According to the clutch control device described in (2) above of the present invention, it is possible to obtain highly accurate acceleration information as compared with the case where acceleration is calculated from detection information such as a wheel speed sensor for detecting vehicle speed.

According to the clutch control device described in (3) above of the present invention, when the pitch angle of the vehicle body increases (in the case of a wheelie), the pitch angle of the vehicle body tends to increase, so the acceleration is limited to suppress the wheelie. becomes more severe. Therefore, by lowering the upper limit of acceleration in accordance with an increase in the vehicle body pitch angle, it is possible to increase the certainty of wheelie control. In addition, since the vehicle body behavior detection means serves both as an acceleration sensor and as a vehicle attitude sensor, it is possible to simplify the system configuration.

According to the clutch control device described in (4) above of the present invention, by setting the upper limit of acceleration to an acceleration at which the front wheel ground load is equal to or lower than the lower limit, it is possible to increase the certainty of wheelie control.

According to the clutch control device described in (5) above of the present invention, the upper limit value of acceleration in the traveling direction of the vehicle is calculated based on the angle formed by the road surface and the line segment connecting the rear wheel contact position and the center of gravity of the vehicle. By doing so, the maximum acceleration can be achieved within the range where the vehicle does not wheelie.

According to the clutch control device described in (6) above of the present invention, front wheel lift (wheelie) or the like can be detected from the difference in rotational speed between the front and rear wheels using the front and rear wheel speed sensors that detect the rotational speed of the front and rear wheels. and When the wheelie of the vehicle body is detected, the acceleration of the vehicle body is suppressed by controlling the clutch capacity. As a result, the maximum acceleration can be achieved within a range in which the vehicle does not wheelie, and acceleration control can be achieved with good responsiveness.

1 is a left side view of a motorcycle according to an embodiment of the present invention; FIG. FIG. 2 is a cross-sectional view of the transmission and change mechanism of the motorcycle; 1 is a schematic illustration of a clutch actuation system including a clutch actuator; FIG. 1 is a block diagram of a transmission system; FIG. 4 is a graph showing changes in hydraulic pressure supplied to a clutch actuator; 4 is a graph showing the correlation between the amount of clutch lever operation, sensor output voltage, and clutch capacity in the embodiment of the present invention; It is an explanatory view showing transition of clutch control mode in the embodiment of the present invention. FIG. 3 is an explanatory diagram showing a state of the vehicle body when the motorcycle is stationary; FIG. 4 is an explanatory diagram showing the state of the vehicle body during acceleration of the motorcycle; FIG. 4 is an explanatory diagram showing the state of the vehicle body during a wheelie of the motorcycle; 4 is a graph showing an overview of parameter changes during acceleration of the motorcycle.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. Unless otherwise specified, directions such as front, rear, left, and right in the following description are the same as directions in the vehicle described below. An arrow FR indicating the front of the vehicle, an arrow LH indicating the left of the vehicle, and an arrow UP indicating the upper side of the vehicle are shown at appropriate locations in the drawings used in the following description.

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

The vehicle body frame 5 includes a head pipe 6, a main tube 7 extending downward and rearward from the head pipe 6 at the center in the vehicle width direction (left and right direction), left and right pivot frames 8 continuing below the rear end of the main tube 7, and a main tube. A seat frame 9 connected to the rear of the tube 7 and the left and right pivot frames 8 is provided. A front end portion of a swing arm 11 is swingably pivoted to the left and right pivot frames 8 . A rear wheel 12 of the motorcycle 1 is supported at the rear end of the swing arm 11 .

A fuel tank 18 is supported above the left and right main tubes 7 . Behind the fuel tank 18 and above the seat frame 9, a front seat 19 and a rear seat cover 19a are supported side by side in the front-rear direction. The seat frame 9 is surrounded by a rear cowl 9a. A power unit PU, which is a prime mover of the motorcycle 1, is suspended below the left and right main tubes 7 . The power unit PU is linked to the rear wheel 12 via, for example, a chain transmission mechanism.

Power unit PU integrally has an engine (internal combustion engine, prime mover) 13 located on the front side and a transmission 21 located on the rear side. The engine 13 is, for example, a multi-cylinder engine in which the rotation axis of the crankshaft 14 extends in the left-right direction (vehicle width direction). The engine 13 has a cylinder 16 erected above the front portion of the crankcase 15 . A rear part of the crankcase 15 is a transmission case 17 that accommodates the transmission 21 .

<Transmission>
As shown in FIG. 2, the transmission 21 is a stepped transmission having a main shaft 22, a counter shaft 23, and a transmission gear group 24 extending over both shafts 22,23. The countershaft 23 constitutes the transmission 21 and also the output shaft of the power unit PU. The end of the countershaft 23 protrudes to the rear left side of the crankcase 15 and is connected to the rear wheel 12 via the chain type transmission mechanism.

The transmission gear group 24 has gears supported by both shafts 22 and 23 for the number of gears. The transmission 21 is of a constant mesh type in which corresponding gear pairs of a transmission gear group 24 are always meshed between both shafts 22 and 23 . A plurality of gears supported by both shafts 22 and 23 are classified into free gears rotatable with respect to the corresponding shafts and slide gears (shifters) spline-fitted with the corresponding shafts. One of the free gear and the slide gear is provided with an axially convex dog, and the other is provided with an axially concave slot for engaging the dog. That is, the transmission 21 is a so-called dog transmission.

A main shaft 22 and a counter shaft 23 of the transmission 21 are arranged side by side behind the crankshaft 14 in the front-rear direction. A clutch device 26 operated by a clutch actuator 50 (see FIG. 3) is coaxially arranged at the right end of the main shaft 22 . The clutch device 26 is, for example, a wet multi-plate clutch, a so-called normally open clutch. That is, the clutch device 26 is in a connected state in which power can be transmitted by the hydraulic pressure supplied from the clutch actuator 50, and returns to a disconnected state in which power cannot be transmitted when the hydraulic pressure from the clutch actuator 50 is no longer supplied.

Rotational power of the crankshaft 14 is transmitted to the main shaft 22 via the clutch device 26 and transmitted from the main shaft 22 to the counter shaft 23 via any gear pair of the transmission gear group 24 . A drive sprocket 27 of the chain transmission mechanism is attached to the left end portion of the countershaft 23 that protrudes to the rear left side of the crankcase 15 .

A change mechanism 25 for switching gear pairs of a transmission gear group 24 is accommodated in the upper rear portion of the transmission 21 . The change mechanism 25 rotates a hollow cylindrical shift drum 36 parallel to both shafts 22 and 23 to operate a plurality of shift forks 36a in accordance with the pattern of lead grooves formed on the outer circumference of the shift drum 36. The pair of gears used for power transmission between the shafts 22 and 23 in is switched.

The change mechanism 25 has a shift spindle 31 parallel to a shift drum 36 . When the shift spindle 31 rotates, the shift arm 31a fixed to the shift spindle 31 rotates the shift drum 36, moves the shift fork 36a in the axial direction according to the pattern of the lead grooves, and powers the transmission gear group 24. Switching a transmittable pair of gears (i.e. switching gears).

Referring also to FIG. 1 , the shift spindle 31 has a shaft outer portion 31 b protruding outward (to the left) of the crankcase 15 in the vehicle width direction so that the change mechanism 25 can be operated. A shift load sensor 42 (shift operation detection means) is coaxially attached to the shaft outer portion 31 b of the shift spindle 31 . A swing lever 33 is attached to the shaft outer portion 31b of the shift spindle 31 (or the rotation shaft of the shift load sensor 42). The rocking lever 33 extends rearward from a base end 33a clamped to the shift spindle 31 (or a rotating shaft), and has a top end 33b on which the upper end of the link rod 34 rocks via an upper ball joint 34a. movably connected. A lower end portion of the link rod 34 is pivotably connected to a shift pedal 32 operated by the foot of the driver via a lower ball joint (not shown).

As shown in FIG. 1, the shift pedal 32 is supported at its front end on the lower portion of the crankcase 15 via a shaft extending in the left-right direction so as to be vertically swingable. A rear end portion of the shift pedal 32 is provided with a pedal portion on which the foot of the driver placed on the step 32a is hooked.

As shown in FIG. 2 , a shift change device 35 for switching gears of the transmission 21 includes the shift pedal 32 , the link rod 34 and the change mechanism 25 . In the shift change device 35, an assembly (a shift drum 36, a shift fork 36a, etc.) for switching the gear stage of the transmission 21 in the transmission case 17 is shifted by a shift operation to the shift operation portion 35a and the shift pedal 32. An assembly (the shift spindle 31, the shift arm 31a, etc.) that rotates around the axis of the spindle 31 and transmits this rotation to the shift operation portion 35a is called a shift operation receiving portion 35b.

Here, in the motorcycle 1, only the shift operation of the transmission 21 (foot operation of the shift pedal 32) is performed by the driver, and the connection/disengagement operation of the clutch device 26 is automatically performed by electric control according to the operation of the shift pedal 32. A so-called semi-automatic transmission system (automatic clutch type transmission system) is adopted.

<Transmission system>
As shown in FIG. 4, the transmission system includes a clutch actuator 50, an ECU 60 (Electronic Control Unit), and various sensors 40-45.
The ECU 60 includes an acceleration sensor 40 (vehicle behavior detection means) that detects the behavior of the vehicle body, a gear position sensor 41 that detects the gear stage from the rotation angle of the shift drum 36, and a shift sensor that detects the operation torque input to the shift spindle 31. Detection information from a load sensor 42 (for example, a torque sensor), and various information from a throttle opening sensor 43 that detects throttle opening, a vehicle speed sensor 44 that detects vehicle speed, and an engine speed sensor 45 that detects engine speed. Based on vehicle state detection information and the like, the clutch actuator 50 is operated and controlled, and the ignition device 46 and the fuel injection device 47 are operated and controlled.

The acceleration sensor (gyro sensor) 40 is a 5-axis or 6-axis IMU (Inertial Measurement Unit), and detects acceleration components related to the 3 axes (roll axis, pitch axis, yaw axis) of the vehicle body. Output to the ECU 60 . The acceleration sensor 40 may be built in the ECU 60 .
The vehicle speed sensor 44 includes a front wheel speed sensor 44f that detects the rotational speed of the front wheels 2 and a rear wheel speed sensor 44r that detects the rotational speed of the rear wheels 12. As shown in FIG. Engine speed is controlled by a throttle by wire (TBW) including a throttle valve and accelerator grip.

The ECU 60 also receives detection information from oil pressure sensors 57 and 58 and a shift operation detection switch (shift neutral switch) 48, which will be described later.
The ECU 60 also includes a hydraulic control section (clutch control section) 61 and a behavior calculation section 62, the functions of which will be described later. Reference numeral 60A in the figure indicates the clutch control device of this embodiment.

Also referring to FIG. 3 , the clutch actuator 50 is controlled by the ECU 60 to control the hydraulic pressure that connects and disconnects 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 master cylinder 51 driven by the motor 52 . The clutch actuator 50 constitutes an integrated clutch control unit 50A together with a hydraulic circuit device 53 provided between the master cylinder 51 and the hydraulic pressure supply/discharge port 50p.
The ECU 60 calculates a target value (target hydraulic pressure) of the hydraulic pressure to be supplied to the slave cylinder 28 in order to connect and disconnect the clutch device 26 based on a preset calculation program, and calculates the slave cylinder pressure detected by the downstream hydraulic sensor 58. The clutch control unit 50A is controlled so that the oil pressure on the 28 side (slave oil pressure) approaches the target oil pressure.

The master cylinder 51 strokes the piston 51 b in the cylinder body 51 a by driving the motor 52 so that the working oil in the cylinder body 51 a can be supplied to and discharged from the slave cylinder 28 . In the drawing, reference numeral 55 denotes a conversion mechanism as a ball screw mechanism, reference numeral 54 denotes a transmission mechanism extending over the motor 52 and the conversion mechanism 55, and reference numeral 51e denotes a reservoir connected to the master cylinder 51, respectively.

The hydraulic circuit device 53 has a valve mechanism (solenoid valve 56) that opens or shuts off an intermediate portion of a main oil passage (hydraulic supply/discharge oil passage) 53m extending from the master cylinder 51 to the clutch device 26 side (slave cylinder 28 side). is doing. A main oil passage 53m of the hydraulic circuit device 53 is divided into an upstream oil passage 53a on the master cylinder 51 side of the solenoid valve 56 and a downstream oil passage 53b on the slave cylinder 28 side of the solenoid valve 56. . The hydraulic circuit device 53 further includes a bypass oil passage 53c that bypasses the solenoid valve 56 and communicates the upstream oil passage 53a and the downstream oil passage 53b.

The solenoid valve 56 is a so-called normally open valve. The bypass oil passage 53c is provided with a one-way valve 53c1 that allows hydraulic oil to flow only from the upstream side to the downstream side. An upstream oil pressure sensor 57 is provided on the upstream side of the solenoid valve 56 to detect the oil pressure of the upstream oil passage 53a. A downstream oil pressure sensor 58 is provided downstream of the solenoid valve 56 to detect the oil pressure of the downstream oil passage 53b.

As shown in FIG. 1, the clutch control unit 50A is accommodated, for example, in the rear cowl 9a. The slave cylinder 28 is attached to the rear left side of the crankcase 15 . The clutch control unit 50A and the slave cylinder 28 are connected via hydraulic piping 53e (see FIG. 3).

As shown in FIG. 2, the slave cylinder 28 is coaxially arranged to the left of the main shaft 22 . The slave cylinder 28 pushes a push rod 28a penetrating through the main shaft 22 to the right when hydraulic pressure is supplied from the clutch actuator 50 . The slave cylinder 28 presses the push rod 28a to the right to operate the clutch device 26 to the connected state via the push rod 28a. When the hydraulic pressure is no longer supplied, the slave cylinder 28 releases the push rod 28a and returns the clutch device 26 to the disengaged state.

In order to maintain the clutch device 26 in the connected state, it is necessary to continue supplying hydraulic pressure, which consumes electric power accordingly. Therefore, as shown in FIG. 3, a solenoid valve 56 is provided in the hydraulic circuit device 53 of the clutch control unit 50A, and the solenoid valve 56 is closed after hydraulic pressure is supplied to the clutch device 26 side. As a result, the hydraulic pressure supplied to the clutch device 26 side is maintained, and the hydraulic pressure is supplemented by the pressure drop (recharged by the leak amount), thereby suppressing energy consumption.

<Clutch control>
Next, the action of the clutch control system will be described with reference to the graph of FIG. In the graph of FIG. 5, the vertical axis indicates the supply oil pressure detected by the downstream side oil pressure sensor 58, and the horizontal axis indicates the elapsed time.
When the motorcycle 1 is stopped (idling), the solenoid valve 56 controlled by the ECU 60 is open. At this time, the slave cylinder 28 side (downstream side) is in a low pressure state lower than the touch point oil pressure TP, and the clutch device 26 is in a non-engaged state (disconnected state, released state). This state corresponds to region A in FIG.
When the vehicle is stopped in the in-gear state, electric power is supplied to the motor 52 to generate a slight hydraulic pressure. This is to immediately continue the clutch and start the vehicle.

When the motorcycle 1 is started, when the rotation speed of the engine 13 is increased, electric power is supplied only to the motor 52, and hydraulic pressure is supplied from the master cylinder 51 to the slave cylinder 28 via the open solenoid valve 56. When the oil pressure on the side of the slave cylinder 28 (downstream side) rises to the touch point oil pressure TP or higher, the clutch device 26 starts to be engaged, and the clutch device 26 enters a half-clutch state in which part of the power can be transmitted. This allows the motorcycle 1 to start smoothly. This state corresponds to region B in FIG.
Eventually, the difference between the input rotation and the output rotation of the clutch device 26 decreases, and when the oil pressure on the slave cylinder 28 side (downstream side) reaches the lower limit holding oil pressure LP, the engagement of the clutch device 26 shifts to the locked state, and the engine 13 are all transmitted to the transmission 21 . This state corresponds to region C in FIG. Areas A to C are assumed to be departure areas.

When hydraulic pressure is supplied from the master cylinder 51 side to the slave cylinder 28 side, the solenoid valve 56 is opened and the motor 52 is energized to rotate forward, thereby pressurizing the master cylinder 51 . As a result, the hydraulic pressure on the side of the slave cylinder 28 is adjusted to the clutch engagement hydraulic pressure. At this time, the driving of the clutch actuator 50 is feedback-controlled based on the hydraulic pressure detected by the downstream hydraulic sensor 58 .

When the hydraulic pressure on the side of the slave cylinder 28 (downstream side) reaches the upper limit holding hydraulic pressure HP, power is supplied to the solenoid valve 56 to close the solenoid valve 56, and the power supply to the motor 52 is stopped. to stop hydraulic pressure generation. That is, the hydraulic pressure is released on the upstream side to be in a low pressure state, while the downstream side is maintained in a high pressure state (upper limit holding hydraulic pressure HP). As a result, the clutch device 26 is maintained in the engaged state without the master cylinder 51 generating hydraulic pressure, enabling the motorcycle 1 to travel while reducing power consumption.

Here, depending on the shift operation, it is possible that the shift is performed immediately after the hydraulic pressure is applied to the clutch device 26 . In this case, before the solenoid valve 56 is closed and the upstream side is brought into a low pressure state, the motor 52 is reversely driven while the solenoid valve 56 remains open to reduce the pressure in the master cylinder 51 and communicate the reservoir 51e. , and the hydraulic pressure on the clutch device 26 side is relieved to the master cylinder 51 side. At this time, the drive of the clutch actuator 50 is feedback-controlled based on the hydraulic pressure detected by the upstream hydraulic pressure sensor 57 .

Even when the solenoid valve 56 is closed and the clutch device 26 is maintained in the engaged state, the hydraulic pressure on the downstream side gradually decreases (leaks) as shown in region D in FIG. That is, the hydraulic pressure on the downstream side gradually decreases due to factors such as hydraulic pressure leakage due to deformation of the seals of the solenoid valve 56 and the one-way valve 53c1 and temperature drop.

On the other hand, as shown in region E in FIG. 5, the downstream hydraulic pressure may rise due to temperature rise or the like. Minor hydraulic pressure fluctuations on the downstream side can be absorbed by an accumulator (not shown), and power consumption does not increase by operating the motor 52 and the solenoid valve 56 each time the hydraulic pressure fluctuates.
When the downstream hydraulic pressure rises to the upper limit holding hydraulic pressure HP as shown in region E in FIG. to the upstream side.

As in area F in FIG. 5, when the downstream hydraulic pressure drops to the lower limit holding hydraulic pressure LP, the solenoid valve 56 remains closed and power supply to the motor 52 is started to increase the upstream hydraulic pressure. When the upstream hydraulic pressure exceeds the downstream hydraulic pressure, this hydraulic pressure is supplied (recharged) to the downstream side via the bypass oil passage 53c and the one-way valve 53c1. When the downstream hydraulic pressure reaches the upper limit holding hydraulic pressure HP, power supply to the motor 52 is stopped to stop generation of hydraulic pressure. As a result, the downstream hydraulic pressure is maintained between the upper limit holding pressure HP and the lower limit holding pressure LP, and the clutch device 26 is maintained in the engaged state. Regions D to F are cruise regions.

When the transmission 21 is put into neutral while the motorcycle 1 is stopped, both power supply to the motor 52 and the solenoid valve 56 are stopped. As a result, the master cylinder 51 stops generating hydraulic pressure and stops supplying hydraulic pressure to the slave cylinder 28 . The solenoid valve 56 is opened, and the hydraulic pressure in the downstream oil passage 53b is returned to the reservoir 51e. As a result, the slave cylinder 28 side (downstream side) is in a low pressure state lower than the touch point oil pressure TP, and the clutch device 26 is in a non-engaged state. This state corresponds to regions G and H in FIG. Regions G and H are defined as stop regions.
When the transmission 21 is in the neutral state when the motorcycle 1 is stopped, power supply to the motor 52 is interrupted and the motorcycle 1 is stopped. Therefore, the hydraulic pressure becomes close to zero.

On the other hand, if the transmission 21 remains in gear when the motorcycle 1 is stopped, the slave cylinder 28 side is in a standby state in which the standby oil pressure WP is applied.
The standby oil pressure WP is an oil pressure that is slightly lower than the touch point oil pressure TP that initiates engagement of the clutch device 26, and is an oil pressure that does not engage the clutch device 26 (oil pressure applied in regions A and H in FIG. 5). By applying the standby oil pressure WP, it is possible to disable the clutch device 26 (cancellation of backlash and operation reaction force of each part, application of preload to the hydraulic path, etc.), and the operation response of the clutch device 26 when engaged is enhanced.

<Shift control>
Next, the shift control of the motorcycle 1 will be described.
In the motorcycle 1 of this embodiment, when the gear position of the transmission 21 is in the in-gear state of 1st gear and the vehicle speed is in the in-gear stop state of less than the set value corresponding to stopping, the shift pedal 32 shifts from 1st gear to neutral. When the shift operation is performed, control is performed to lower the standby oil pressure WP supplied to the slave cylinder 28 .

Here, when the motorcycle 1 is in a stopped state and the gear position of the transmission 21 is in any gear stage position other than neutral, that is, when the transmission 21 is in an in-gear stop state, the slave cylinder 28 is supplied with a preset standby oil pressure WP.

The standby hydraulic pressure WP is normally set to the first set value P1 (see FIG. 5), which is the standard standby hydraulic pressure (in the non-detection state in which the shift operation of the shift pedal 32 is not detected). As a result, the clutch device 26 is put into a standby state in which the clutch device 26 is disabled, and the responsiveness when the clutch is engaged is enhanced. That is, when the driver increases the throttle opening to increase the rotation speed of the engine 13, hydraulic pressure is supplied to the slave cylinder 28 to immediately start engaging the clutch device 26, and the motorcycle 1 can start and accelerate quickly. It becomes possible.

The motorcycle 1 includes a shift operation detection switch 48 in addition to the shift load sensor 42 in order to detect the shift operation of the shift pedal 32 by the driver.
When the shift operation detection switch 48 detects a shift operation from first speed to neutral in the in-gear stop state, the hydraulic control unit 61 sets the standby hydraulic pressure WP to the first set value P1 before the shift operation. is set to a lower second set value P2 (low standby oil pressure, see FIG. 5).

When the transmission 21 is in the in-gear state, the standard standby hydraulic pressure corresponding to the first set value P1 is normally supplied to the slave cylinder 28, so that the clutch device 26 slightly drags. At this time, the dogs and slots (dog holes) that mesh with each other in the dog clutch of the transmission 21 may press against each other in the rotational direction, causing resistance to disengagement and making the shift operation heavy. In such a case, if the standby hydraulic pressure WP supplied to the slave cylinder 28 is reduced to a low standby hydraulic pressure corresponding to the second set value P2, the engagement between the dog and the slot can be easily released, and the shift operation can be lightened. Become.

<Clutch control mode>
As shown in FIG. 7, the clutch control device 60A of this embodiment has three types of clutch control modes. The clutch control mode is an auto mode M1 for automatic control, a manual mode M2 for manual operation, and a manual intervention mode M3 for temporary manual operation. ) and the operation of the clutch lever 4b (see FIG. 1). A target including the manual mode M2 and the manual intervention mode M3 is referred to as a manual system M2A.

The auto mode M1 is a mode in which the clutch device 26 is controlled by calculating a clutch capacity suitable for the running state through automatic start/shift control. The manual mode M2 is a mode in which the clutch capacity is calculated and the clutch device 26 is controlled according to the clutch operation instruction from the passenger. The manual intervention mode M3 is a temporary manual operation mode in which a clutch operation instruction from the passenger is received during the auto mode M1, and the clutch capacity is calculated from the clutch operation instruction to control the clutch device 26. FIG. It should be noted that when the occupant stops operating (completely releases) the clutch lever 4b during the manual intervention mode M3, it is set to return to the auto mode M1.

The clutch control device 60A of this embodiment drives the clutch actuator 50 (see FIG. 3) to generate the clutch control hydraulic pressure. Therefore, the clutch control device 60A starts control from the clutch-off state (disengaged state) in the auto mode M1 when the system is started. Further, the clutch control device 60A is set so as to return to clutch off in the auto mode M1 because clutch operation is unnecessary when the engine 13 is stopped.

The automatic mode M1 basically performs clutch control automatically, and allows the motorcycle 1 to run without lever operation. In auto mode M1, the clutch capacity is controlled based on the throttle opening, engine speed, vehicle speed, and shift sensor output. As a result, the motorcycle 1 can be started without engine stall (engine stop or engine stall) only by operating the throttle, and can be shifted only by shifting. However, the clutch device 26 may be automatically disengaged at extremely low speeds equivalent to idling. Further, in the automatic mode M1, by gripping the clutch lever 4b, the manual intervention mode M3 is entered, and the clutch device 26 can be arbitrarily disengaged.

On the other hand, in the manual mode M2, the clutch capacity is controlled by lever operation by the passenger. The automatic mode M1 and the manual mode M2 can be switched by operating the clutch control mode changeover switch 59 (see FIG. 4) while the vehicle is stopped. Note that the clutch control device 60A may include an indicator that indicates that the lever operation is effective when transitioning to the manual system M2A (manual mode M2 or manual intervention mode M3).

In the manual mode M2, clutch control is basically performed manually, and the clutch hydraulic pressure can be controlled according to the operating angle of the clutch lever 4b. As a result, the connection and disconnection of the clutch device 26 can be controlled according to the passenger's intention, and the vehicle can be driven with the clutch device 26 connected even at extremely low speeds equivalent to idling. However, depending on the lever operation, the engine may stall, and automatic start by throttle operation alone is not possible. Even in the manual mode M2, the clutch control automatically intervenes during the shift operation.

In the auto mode M1, the clutch actuator 50 automatically engages and disengages the clutch device 26, but manual clutch operation is performed on the clutch lever 4b to temporarily intervene in the automatic control of the clutch device 26. (manual intervention mode M3).

As shown in FIG. 6, the operation amount (rotational angle) of the clutch lever 4b and the output value of the clutch lever operation amount sensor 4c are in a proportional relationship (correlation) with each other. The ECU 60 calculates the target hydraulic pressure of the clutch device 26 based on the output value of the clutch lever operation amount sensor 4c. The actual hydraulic pressure (slave hydraulic pressure) generated in the slave cylinder 28 follows the target hydraulic pressure with a delay corresponding to the pressure loss.

<Manual clutch operation>
As shown in FIG. 1, a clutch lever 4b as a manual clutch operator is attached to the base end side (inner side in the vehicle width direction) of the left grip of the steering handle 4a. The clutch lever 4 b is not mechanically connected to the clutch device 26 using a cable, hydraulic pressure, or the like, and functions as an operator that transmits a clutch actuation request signal to the ECU 60 . That is, the motorcycle 1 employs a clutch-by-wire system in which the clutch lever 4b and the clutch device 26 are electrically connected.

Also referring to FIG. 4, the clutch lever 4b is integrally provided with a clutch lever operation amount sensor 4c for detecting the operation amount (rotational angle) of the clutch lever 4b. The clutch lever operation amount sensor 4c converts the operation amount of the clutch lever 4b into an electric signal and outputs the electric signal. When the operation of the clutch lever 4b is effective (manual system M2A), the ECU 60 drives the clutch actuator 50 based on the output of the clutch lever operation amount sensor 4c. The clutch lever 4b and the clutch lever operation amount sensor 4c may be integrated with each other or may be separated from each other.

The motorcycle 1 includes a clutch control mode changeover switch 59 for switching the control mode of clutch operation. The clutch control mode changeover switch 59 arbitrarily switches between an automatic mode M1 in which clutch control is automatically performed under predetermined conditions and a manual mode M2 in which clutch control is manually performed according to the operation of the clutch lever 4b. make it possible. For example, the clutch control mode changeover switch 59 is provided on a handle switch attached to the steering handle 4a. This allows the occupant to easily operate during normal driving.

Also referring to FIG. 6, the clutch lever 4b is in a released state in which it is released and rotated to the clutch connection side without being gripped by the occupant, and is rotated to the grip side (clutch disengagement side) by being gripped by the occupant. and the abutting state in which it abuts against the grip. The clutch lever 4b is urged to return to the released state, which is the initial position, when released from the gripping operation by the passenger.

For example, the clutch lever operation amount sensor 4c sets the output voltage to zero when the clutch lever 4b is completely gripped (abutting state), and from this state, the release operation of the clutch lever 4b (operation to the clutch engagement side) is stopped. It is arranged to increase the output voltage depending on what is done. In this embodiment, of the output voltage of the clutch lever operation amount sensor 4c, there is a lever play that exists when the clutch lever 4b starts to be gripped, and a gap large enough for a finger to be inserted is secured between the lever that is gripped and the grip. The effective voltage range (the effective operation range of the clutch lever 4b) is set to the range excluding the collision margin.

Specifically, the effective voltage is applied between the operation amount S1 at which the clutch lever 4b is released by the amount of the abutment allowance from the abutting state of the clutch lever 4b and the operation amount S2 at which the clutch lever 4b is released until the lever play begins. is set so as to correspond to the range from the lower limit value E1 to the upper limit value E2 of . The range from the lower limit value E1 to the upper limit value E2 corresponds to the range from zero to MAX of the calculated value of the manually operated clutch capacity in a proportional relationship. As a result, it is possible to reduce the effects of mechanical backlash, sensor variation, and the like, and improve the reliability of the clutch driving amount required by manual operation. The effective voltage may be set to the upper limit value E2 when the clutch lever 4b is operated by S1, and may be set to be the lower limit value E1 when the operation amount is S2.

<Vehicle behavior control during sudden acceleration>
Next, clutch control for stabilizing the vehicle body behavior during rapid acceleration of the motorcycle 1 will be described.
For example, when the engine is rotated at a high speed (for example, 10,000 rpm or more) and the clutch device 26 is engaged and the motorcycle 1 is started with rapid acceleration, the motorcycle 1 may wheelie. When the motorcycle 1 is rapidly accelerated, the vehicle body may undergo excessive pitching in the backward rotation direction, causing the front wheels 2 to lift from the road surface (separate above the road surface). Since this vehicle body behavior causes loss in acceleration of the motorcycle 1, the following control is performed in this embodiment in order to prevent this. In this embodiment, when an acceleration state that causes the motorcycle 1 to roll backward (wheelie) is detected, control is performed to decrease the clutch capacity and slow down the acceleration.

The clutch control device 60A of this embodiment drives and controls the clutch actuator 50 so that the acceleration of the vehicle body in the longitudinal direction of the vehicle does not exceed a predetermined upper limit value. The clutch control device 60A controls the clutch capacity so that the acceleration of the vehicle body in the longitudinal direction of the vehicle does not exceed a predetermined upper limit value. The acceleration of the vehicle body is detected by an acceleration sensor (gyro unit, IMU) 40 mounted on the vehicle body. The acceleration sensor 40 of this embodiment also functions as an attitude detection sensor that detects the attitude of the vehicle body (especially the pitch angle). Detection information of the acceleration sensor 40 is output to the control device (ECU 60). Based on the information detected by the acceleration sensor 40, the ECU 60 controls the clutch actuator 50 to reduce the clutch capacity when the change in posture of the two-wheeled motor vehicle 1 as it moves upward forward exceeds a predetermined level.

Referring to FIG. 8, the predetermined upper limit of acceleration is calculated with respect to the inertial force acting on the vehicle body when motorcycle 1 accelerates. The upper limit value is calculated with respect to the acceleration (relative acceleration) a acting on the vehicle body relatively toward the rear of the vehicle when the motorcycle 1 is accelerated forward (in the direction of travel). The upper limit value corresponds to the acceleration when the ground load (also road surface reaction force) of the front wheels 2 drops below a predetermined value (for example, equivalent to 0N). The upper limit value is calculated based on the angle φ between a line segment r connecting the rear wheel contact point Prr and the center of gravity position G1, which will be described later, and a straight line (for example, a horizontal line) r0 along the road surface rm when viewed from the side of the vehicle. (Formula 2 below).

The ECU 60 estimates the wheelie situation of the motorcycle 1 using the IMU information. Specifically, the ECU 60 determines whether or not the vehicle is in a wheelie state in which the front wheels 2 are lifted (the front wheel ground load Ffr is equal to or less than a predetermined value). When the ECU 60 determines that the motorcycle 1 is in a wheelie state, the ECU 60 controls the clutch device 26 as follows. By reducing the clutch capacity, the ECU 60 adjusts the driving force (acceleration a) appropriately while maintaining the engine speed. At this time, the ECU 60 also controls the TBW as needed.

The ECU 60 can also estimate the wheelie state of the motorcycle 1 based on the detected information about the rotational speeds of the front and rear wheels 2 and 12 . The ECU 60 reduces the clutch capacity when the difference between the rotational speeds of the front and rear wheels 2, 12 detected by the front and rear wheel speed sensors 44f, 44r exceeds a predetermined value. This also allows adjustment to an appropriate driving force (acceleration a) while maintaining the engine speed.
That is, the ECU 60 can use at least one of the IMU information and the front and rear wheel speed difference to estimate the wheelie condition of the motorcycle 1 and control the clutch capacity.

In the case of acceleration control by engine output control using TBW, there is a problem in terms of responsiveness because the time lag required for increasing or decreasing the engine output is relatively large. In the case of acceleration control by clutch capacity control, since the time lag required for increasing or decreasing the clutch capacity is relatively small, it is possible to realize highly responsive acceleration control.

In the present embodiment, clutch capacity control is executed aiming at an upper limit acceleration at which the front wheel 2 does not lift off the road surface rm so that the maximum acceleration of the motorcycle 1 can be obtained.
FIG. 8 shows the stationary state of the motorcycle 1 . In the figure, G1 is the center of gravity position (predetermined imaginary center of gravity) of the mass M that is the sum of the vehicle weight and the rider weight, L is the wheel base of the front and rear wheels 2 and 12 in the longitudinal direction of the vehicle, and Lr is the rear wheel contact. The length of the line segment r connecting the point Prr and the center-of-gravity position G1 is shown. The mass M balances the sum of the front wheel road surface reaction force Ffr input to the front wheel grounding point Pfr at the lower end of the front wheel 2 and the rear wheel road surface reaction force Frr at the rear wheel grounding point Prr at the lower end of the rear wheel 12 . In the stationary state of the motorcycle 1, the straight line connecting the front wheel grounding point Pfr and the rear wheel grounding point Prr is a straight line (horizontal line) r0 along the road surface rm.

FIG. 9 shows the motorcycle 1 during acceleration in the traveling direction (forward). In the figure, the symbol a0 indicates the acceleration to the front of the vehicle generated in the vehicle body by driving the rear wheels 12, and the symbol a indicates the relative acceleration to the rear of the vehicle generated at the center of gravity position G1 due to the inertial force. The center of gravity position G1 located above the road surface rm tries to move (swing) rearward around the rear wheel contact point Prr by receiving the relative acceleration a. As a result, the front wheel road surface reaction force Ffr decreases and the rear wheel road surface reaction force Frr increases. The relationship between the moment at the center of the rear wheel contact point Prr at this time is shown in Equation 1 below.

r・M((sinφ)・a−(cosφ)・g)+L・Ffr=0 Equation 1

In Equation 1, the wheelie state occurs when the front wheel road surface reaction force Ffr becomes zero.
The behavior calculation unit 62 of the ECU 60 sets the upper limit value of the acceleration a so that the following formula 2 holds, for example. That is, the acceleration a is limited (in this embodiment, the clutch capacity is limited) so that the following formula 2 holds. As a result, the wheelie of the motorcycle 1 is suppressed. Formula 2 assumes the maximum possible front-down attitude before and after the wheelie (the attitude just before the front wheels 2 separate from the road surface rm).

r M ((sin φ) a-(cos φ) g) < 0 Equation 2

FIG. 10 shows a state in which the motorcycle 1 wheelies by a predetermined angle when the motorcycle 1 is accelerated in the direction of travel. In the drawing, the symbol θ indicates an upward angle (wheelie angle, pitch angle) of a straight line r2 corresponding to a tangent to the lower end positions of the front and rear wheels 2,12. At this time, the relationship between the moment at the center of the rear wheel ground contact point Prr is set so that the following formula 3 is established.

r M ((sin (φ + θ) a - (cos (φ + θ)) g) < 0 Equation 3

Formula 3 holds because, in the relationship between the moment at the center of the rear wheel ground contact point Prr, the backward turning moment due to the acceleration a acting on the center of gravity position G1 toward the rear of the vehicle is the forward turning moment due to the gravitational acceleration g acting on the center of gravity position G1. Indicates that it is less than the moment. If Expression 3 does not hold, the motorcycle 1 enters a wheelie state and the wheelie angle θ gradually increases. In this case, the limit value of the acceleration a (clutch capacity) is set more severely (lower). That is, the predetermined upper limit value of the acceleration a is set lower as the wheelie angle θ increases. Therefore, it is preferable in terms of obtaining the maximum acceleration of the motorcycle 1 to limit the acceleration a (clutch capacity) in the attitude just before the front wheel 2 lifts (that is, to satisfy the equation 2).

The ECU 60 temporarily sets the length Lr of the line segment r connecting the rear wheel ground contact point Prr and the center of gravity position G1 and the wheelie angle (pitch angle) θ to limit the acceleration a (clutch capacity).
The ECU 60 restricts the acceleration a more severely as the pitch angle θ increases.
The ECU 60 limits the acceleration a when the pitch angular acceleration exceeds a certain level.
The ECU 60 limits the acceleration a when the front and rear wheel speeds deviate greatly (when at least one of front wheel lift and rear wheel slip is detected).

Referring to FIG. 11, clutch control device 60A sets a clutch hydraulic pressure (target hydraulic pressure) Pt according to clutch operation, and drives and controls clutch actuator 50 according to this target hydraulic pressure Pt. As a result, the clutch control oil pressure (slave oil pressure) Ps is caused to reach the target oil pressure Pt. For convenience of illustration, in FIG. 11, the slave oil pressure Ps and the target oil pressure Pt are indicated by the same line.
When the motorcycle 1 starts suddenly, the target oil pressure Pt sharply rises in response to a quick release operation (clutch engagement operation) of the clutch lever 4b. The target oil pressure Pt eventually rises to the oil pressure p1 just before the clutch device 26 is fully engaged. At this time, the throttle opening Th is also increased by the throttle operation, and the engine speed ne is kept at a high speed.

If the front wheel 2 lifts when the motorcycle 1 suddenly starts, the ECU 60, for example, suppresses an increase in the throttle opening Th to reduce the acceleration a of the motorcycle 1 in order to suppress further lift. In this embodiment, at timing T1 when it is determined that the front wheel 2 lifts, the target hydraulic pressure Pt is set to a wheelie suppression hydraulic pressure p2 that is lower than the operation target hydraulic pressure p1 corresponding to the amount of operation of the clutch lever 4b. As a result, the clutch capacity is reduced to generate slippage (clutch differential rotation, clutch slip) in the clutch device 26, suppress the acceleration a of the motorcycle 1, and suppress an increase in vehicle body wheelie (pitch angle).

As described above, the clutch control device 60A in the above embodiment includes the engine 13, the transmission 21, the clutch device 26 for connecting and disconnecting power transmission between the engine 13 and the transmission 21, and the clutch device. 26 to change the clutch capacity, an ECU 60 that calculates a target value (target hydraulic pressure Pt) of the clutch capacity control parameter (slave hydraulic pressure Ps), and detects the acceleration a of the vehicle body in the longitudinal direction of the vehicle. The ECU 60 controls the clutch capacity so that the acceleration a in the longitudinal direction of the vehicle detected by the acceleration sensor 40 does not exceed a predetermined upper limit value.
According to this configuration, by controlling the clutch capacity so that the acceleration a in the longitudinal direction of the vehicle does not exceed a predetermined upper limit value, the wheelie of the vehicle body is suppressed (the range in which the behavior of the vehicle body in the pitch direction is suppressed). Maximum acceleration can be achieved. In addition, since the vehicle body acceleration is controlled by controlling the clutch capacity, it is possible to realize acceleration control with higher response than acceleration control by engine output control.

In the clutch control device 60A, the acceleration sensor 40 is an acceleration sensor 40 that detects the acceleration a.
According to this configuration, it is possible to obtain highly accurate acceleration information as compared with the case where the acceleration a is calculated from detection information such as a wheel speed sensor for vehicle speed detection.

In the clutch control device 60A, the acceleration sensor 40 also functions as vehicle body attitude detection means for detecting the pitch angle θ of the vehicle body, and the ECU 60 determines in advance the pitch angle θ of the vehicle body detected by the acceleration sensor 40. If it exceeds the specified value, the upper limit value of the acceleration a is lowered.
According to this configuration, when the vehicle body pitch angle θ increases (when the vehicle performs a wheelie), the vehicle body pitch angle θ tends to increase. Therefore, by lowering the upper limit value of the acceleration a as the vehicle body pitch angle increases, the certainty of the wheelie control can be enhanced. In addition, since the vehicle body behavior detection means serves both as an acceleration sensor and as a vehicle attitude sensor, it is possible to simplify the system configuration.

In the clutch control device 60A, the upper limit value of the acceleration a is set to an acceleration value at which the ground contact load Ffr of the front wheels 2 is equal to or lower than a predetermined lower limit value.
According to this configuration, by setting the upper limit of the acceleration a to an acceleration at which the front wheel ground load Ffr is equal to or lower than the lower limit, it is possible to increase the certainty of the wheelie control.

In the clutch control device 60A, the upper limit value of the acceleration a is calculated based on the angle φ between the line segment r connecting the rear wheel ground contact position Prr and the predetermined vehicle center of gravity position G1 and the road surface rm.
According to this configuration, the upper limit value of the acceleration a in the vehicle traveling direction is calculated based on the angle φ between the line segment r connecting the rear wheel ground contact position Prr and the vehicle center of gravity position G1 and the road surface rm. The maximum acceleration can be achieved within the range where the wheelie does not occur.

The clutch control device 60A includes a front wheel speed sensor 44f that detects the rotational speed of the front wheels 2 and a rear wheel speed sensor 44r that detects the rotational speed of the rear wheels 12. The ECU 60 controls the front wheel speed sensor 44f. When the difference between the rotational speeds of the front wheels 2 and the rear wheels 12 detected by the rear wheel speed sensor 44f and the rear wheel speed sensor 44r exceeds a predetermined value, the clutch capacity is reduced.
According to this configuration, by using the front and rear wheel speed sensors 44f and 44r for detecting the rotational speeds of the front and rear wheels 2 and 12, front wheel lift (wheelie) and the like can be detected from the difference in rotational speed between the front and rear wheels 2 and 12. . When the wheelie of the vehicle body is detected, the acceleration of the vehicle body is suppressed by controlling the clutch capacity. As a result, the maximum acceleration can be achieved within a range in which the vehicle does not wheelie, and acceleration control can be achieved with good responsiveness.

The present invention is not limited to the above embodiment, and for example, means for measuring the suspension load may be provided in at least one of the front suspension and the rear suspension, and the clutch capacity may be controlled according to the measurement information. For example, the clutch capacity is limited when at least one of the front suspension load is below a predetermined value and the rear suspension load is above a predetermined value. If at least one of the front and rear suspension loads are constantly measured, the limit just before the wheelie is always known and the clutch capacity can be controlled.
Although it is possible to perform wheelie suppression control by directly detecting pitch angular acceleration with an IMU, in the present embodiment, wheelie suppression control can be performed using an inexpensive acceleration sensor that detects acceleration in the longitudinal direction of the vehicle. . Further, wheelie suppression control can be performed by calculating acceleration using an existing wheel speed sensor.

Application is not limited to a configuration in which the clutch is engaged by increasing the hydraulic pressure and disengaged by decreasing the hydraulic pressure, but may be applied to a configuration in which the clutch is disengaged by increasing the hydraulic pressure and engaged by decreasing the hydraulic pressure.
The clutch operator is not limited to the clutch lever 4b, and may be a clutch pedal or other various operators.
It is not limited to application to a saddle type vehicle in which clutch operation is automated as in the above embodiment, but while maintaining manual clutch operation as a basis, gear shifting is performed by adjusting driving force without performing manual clutch operation under predetermined conditions. It can also be applied to a saddle type vehicle provided with a so-called clutch-less transmission.
The above saddle-riding type vehicle includes all vehicles in which the driver straddles the vehicle body, not only motorcycles (including motorized bicycles and scooter type vehicles), but also three-wheeled vehicles (one front wheel and two rear wheels). , including vehicles with two front wheels and one rear wheel) or four-wheel vehicles, and vehicles including an electric motor as a prime mover.
The configuration in the above embodiment is an example of the present invention, and various modifications, such as replacing the constituent elements of the embodiment with known constituent elements, are possible without departing from the gist of the present invention.

1 Motorcycle (saddle type vehicle)
2 front wheels 12 rear wheels 13 engine (motor)
21 transmission 26 clutch device 40 acceleration sensor 44f front wheel speed sensor 44r rear wheel speed sensor 50 clutch actuator 60 ECU (control unit)
60A Clutch control device a Acceleration Ffr Ground load G1 Vehicle center of gravity position Prr Rear wheel ground contact position Ps Slave oil pressure (control parameter)
Pt Target oil pressure (target value)
r line segment rm road surface θ pitch angle φ angle

Claims (6)

engine and
a gearbox;
a clutch device for connecting and disconnecting power transmission between the engine and the transmission;
a clutch actuator that drives the clutch device to change the clutch capacity;
a control unit that calculates a target value of a control parameter for the clutch capacity;
a vehicle body behavior detection means for detecting acceleration of the vehicle body in the longitudinal direction of the vehicle;
The control unit controls the clutch capacity so that the acceleration in the longitudinal direction of the vehicle detected by the vehicle body behavior detection means does not exceed a predetermined upper limit value,
The clutch control device, wherein the upper limit value of the acceleration is calculated based on an angle formed by a road surface and a line segment connecting a rear wheel ground contact position and a predetermined center of gravity of the vehicle. 2. A clutch control device according to claim 1, wherein said vehicle body behavior detecting means is an acceleration sensor for detecting said acceleration. The vehicle body behavior detection means also functions as vehicle body attitude detection means for detecting the pitch angle of the vehicle body,
2. The control unit reduces the upper limit value of the acceleration when the pitch angle of the vehicle body detected by the vehicle body behavior detection means becomes larger than a predetermined specified value. 2. The clutch control device according to 2. The clutch control device according to any one of claims 1 to 3, wherein the upper limit value of the acceleration is set to an acceleration value that makes the ground load of the front wheels equal to or lower than a predetermined lower limit value. (delete) a front wheel speed sensor that detects the rotational speed of the front wheels;
A rear wheel speed sensor that detects the rotation speed of the rear wheel,
The control unit adjusts the clutch capacity when the difference between the rotational speeds of the front wheels and the rear wheels detected by the front wheel speed sensor and the rear wheel speed sensor respectively becomes equal to or greater than a predetermined specified value. 5. A clutch control device according to any one of claims 1 to 4, characterized in that the clutch control device is reduced.

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