JP7075996B2 - Clutch control device for saddle-riding vehicles - Google Patents

Description

The present invention relates to a clutch control device for a saddle-riding vehicle.
This application claims priority under Japanese Patent Application No. 2018-123814 filed in Japan on June 29, 2018 and Japanese Patent Application No. 2018-204514 filed in Japan on October 30, 2018. , The contents are used here.

In a saddle-mounted vehicle such as a motorcycle, a back torque limiter may be provided in a clutch device for connecting and disconnecting power transmission between a prime mover and a drive wheel. The back torque limiter is a mechanism for limiting the engine brake (including the regenerative brake when the prime mover includes an electric motor) acting on the drive wheels due to the resistance of the prime mover. The back torque limiter mechanically reduces the clutch capacity when a back torque exceeding a specified value acts on the cam mechanism provided in the clutch device. The back torque is the torque at which the engine is rotated by the driving force from the driving wheels when the vehicle is decelerated.
The clutch device releases the back torque by operating the back torque limiter and prevents excessive engine braking from being applied to the drive wheels. On the other hand, in order to secure an appropriate engine brake, the back torque is set to be more than the specified value. The back torque may be greater than or equal to the above specification in a state where the drive wheels are in contact with the ground and are sufficiently gripped (a state in which the drive wheels have a sufficient ground load).
In particular, in a situation where sudden braking is performed from a running state, such as when entering a cornering in a race, the ground contact load of the rear wheels, which are the driving wheels, becomes excessive, and the rear wheels may float from the road surface. If the grip of the rear wheels is lost, the rear wheels will suddenly decelerate when the engine brake is applied. When this suddenly decelerated rear wheel re-grounds with a speed difference with respect to the road surface, a phenomenon (hopping) in which the rear wheel is flipped up in small steps occurs, or a phenomenon in which the rear wheel with a speed difference slips and the vehicle body swings to the left or right. (Snaking) occurs.
The vehicle body behavior due to the deterioration of the ground contact property (rear wheel ground contact property) of the rear wheels, such as hopping and snaking, is likely to occur when the saddle-riding vehicle enters a corner. In this case, since the rider focuses on controlling the vehicle body behavior (restoring the ground contact property of the rear wheels), the acceleration at the start of the corner is affected. Especially in race driving, there are many opportunities to enter corners and the ratio of time required for deceleration is high, so the stability of the vehicle body during deceleration is an important issue.

By the way, in recent saddle-riding vehicles, an automatic clutch system has been proposed in which the clutch device is automatically engaged and disconnected by electric control.
As a method for ensuring the rear wheel contact property at the time of sudden braking in such a system, for example, Patent Document 1 states that the throttle valve is in the fully closed position and the front wheel brake hydraulic pressure is within a certain range. A technique for reducing the clutch capacity and preventing the engine brake from becoming excessive is disclosed. As a result, it is possible to suppress deterioration of the rear wheel contact property due to engine braking during sudden braking.

Japanese Patent Application Laid-Open No. 2003-294062

However, in the above-mentioned conventional technique, it is not determined whether or not the rear wheel is floating (whether or not the ground contact load of the rear wheel is reduced) to reduce the clutch capacity, so that the engine brake is inadvertently lowered. There is a possibility that it will be done.

An object of the present invention is to provide a clutch control device for a saddle-riding vehicle, which can ensure the rear wheel contact property while ensuring an appropriate engine brake even when the contact load of the rear wheels decreases. ..

As a means for solving the above problems, the aspect of the present invention has the following configuration.
(1) The clutch control device for a saddle-riding vehicle according to an aspect of the present invention is between the rear wheels, which are driving wheels, the front wheels, which are driven wheels, the prime mover for traveling, and the prime mover and the rear wheels. A clutch device for connecting and disconnecting power transmission, a clutch actuator for driving the clutch device to change the clutch capacity, and a control unit for calculating a control target value of the clutch capacity are provided, and the control unit is a saddle-riding type. When it is detected that the rear wheels are in a predetermined contact load reduction state when the vehicle is decelerating, slipper control for reducing the clutch capacity is performed.

(2) In the clutch control device for the saddle-riding vehicle according to (1) above, in the control unit, the rear wheel speed, which is the rotation speed of the rear wheels, is compared with the front wheel speed, which is the rotation speed of the front wheels. Then, it may be determined that the rear wheel is in the ground contact load reduced state based on the fact that the difference exceeds a predetermined difference.

(3) In the clutch control device for the saddle-riding vehicle according to (2) above, the control unit corrects the front wheel speed as the rear wheel speed to be compared with the front wheel speed. Wheel speed may be used.

(4) In the clutch control device for the saddle-riding vehicle according to (3) above, the corrected wheel speed is the amount of change of the rear wheel speed at the same time as the front wheel speed at the time of wheel speed correction. It may be obtained by adding.

(5) In the clutch control device for the saddle-riding vehicle according to (3) or (4) above, the saddle-riding vehicle is in an upright posture, and the difference between the front and rear wheel speeds is less than a predetermined value. , The wheel speed correction may be started from a specific time point when the throttle of the prime mover is closed.

(6) In the clutch control device for the saddle-riding vehicle according to any one of (3) to (5) above, the value obtained by dividing the front wheel speed by the corrected wheel speed is used as the first parameter. The value obtained by subtracting the corrected wheel speed from the front wheel speed may be set as the second parameter, and the slipper control may be intervened according to at least one of the first parameter and the second parameter.

(7) In the clutch control device for the saddle-riding vehicle according to (6) above, when the vehicle speed is equal to or higher than the first vehicle speed, the slipper control is intervened according to the first parameter, and the vehicle speed is the first. When the speed is less than one vehicle speed and equal to or higher than the second vehicle speed, the slipper control may be intervened according to the second parameter.

(8) In the clutch control device for the saddle-riding vehicle according to (7) above, when the vehicle speed is lower than the second vehicle speed, the slipper control may be non-intervention.

(9) In the clutch control device for the saddle-mounted vehicle according to any one of (1) to (8) above, the control unit opens the throttle of the prime mover with the slipper control intervening. The intervention of the slipper control may be canceled depending on at least one of the above and the elimination of the ground contact load reduction state of the rear wheel.

(10) In the clutch control device for the saddle-riding vehicle according to (1) above, when the bank angle of the vehicle body is larger than the predetermined value and the deceleration of the vehicle speed is larger than the predetermined value, the clutch capacity is described. The slipper control may be performed to reduce the speed.

According to the clutch control device for the saddle-riding vehicle according to the above (1) of the present invention, the clutch capacity is reduced when it is detected that the ground contact load is lowered to the extent that the rear wheels float during deceleration of the saddle-riding vehicle. It becomes possible to perform slipper control. As a result, it is possible to secure an appropriate engine brake during normal driving in which the ground contact load of the rear wheels is secured, and to shift to slipper control during sudden deceleration such that the rear wheels float. Since the engine brake of the rear wheels is weakened by this slipper control, it is possible to suppress the occurrence of hopping and snakes due to the engine brake when the ground contact load of the rear wheels is released. Therefore, it is possible to ensure the ground contact with the rear wheels when the saddle-riding vehicle decelerates. For example, in the racing use of a saddle-riding vehicle, when entering a corner while suddenly decelerating, the rider can easily concentrate on cornering, which can contribute to the transition to smooth acceleration at the start of the corner. Further, the clutch capacity can be made variable as compared with the mechanical back torque limiter.

According to the clutch control device for the saddle-riding vehicle according to the above (2) of the present invention, the ground contact load of the rear wheels is released because the rear wheel speed is lower than the front wheel speed. Can be determined easily and reliably.

According to the clutch control device for the saddle-riding vehicle according to the above (3) of the present invention, the actual front and rear wheel speeds are affected not only by the difference in the tire outer diameters of the front and rear wheels but also by the change in the tire circumference. .. The change in the circumference of the tire is caused by, for example, the brand of the tire, wear, expansion due to centrifugal force, and the like. Therefore, even if the front and rear wheels rotate without slipping on the road surface, the front and rear wheel speeds may differ as the tire circumference changes.
On the other hand, by calculating the corrected wheel speed for comparison based on the front wheel speed and comparing the corrected wheel speed with the front wheel speed, the rear wheel speed is not affected by the change in the tire circumference. It is possible to accurately detect a decrease in wheel speed and prevent an inadvertent decrease in clutch capacity (engine brake decrease).

According to the clutch control device for the saddle-riding vehicle according to the above (4) of the present invention, the wheel speed is corrected by adding the amount of change in the rear wheel speed to the front wheel speed, so that the correction control is simplified and the system is simplified. The load can be suppressed.

According to the clutch control device for the saddle-riding vehicle according to the above (5) of the present invention, the saddle-riding vehicle is in an upright posture, the throttle of the prime mover is closed, and the difference in front and rear wheel speeds is the rear wheel. Wheel speed correction can be performed accurately by using a state in which the value is less than a predetermined value as a value without slip as a starting reference for wheel speed correction.

According to the clutch control device for the saddle-riding vehicle according to the above (6) of the present invention, an appropriate value is selected from two types of parameters to determine intervention in slipper control (determination that the rear wheels are slipping). In other words, slipper control can be performed with the minimum required frequency by performing slip determination).

According to the clutch control device for a saddle-riding vehicle according to the above (7) of the present invention, it is possible to select an appropriate parameter according to the vehicle speed and perform slip determination.

According to the clutch control device for a saddle-riding vehicle according to the above (8) of the present invention, the system load can be suppressed by non-intervening the slipper control when the vehicle speed is low.

According to the clutch control device for the saddle-riding vehicle according to the above (9) of the present invention, at least one of the fact that the saddle-riding vehicle has shifted to acceleration and that the decrease in the ground contact load of the rear wheels has been eliminated. Correspondingly (in other words, depending on the stability of the vehicle condition), by releasing the slipper control, the clutch capacity can be quickly restored from the reduced state to the connected state.

According to the clutch control device for the saddle-riding vehicle according to the above (10) of the present invention, an accurate wheel speed difference is obtained because the patterns of the tread surfaces of the front and rear wheels are different in the region where the bank angle of the vehicle body is large. When the bank angle of the vehicle body is equal to or greater than a predetermined value, the slipper control of the clutch is performed regardless of the wheel speed difference. As a result, it is possible to appropriately shift to slipper control even when the vehicle body is banked.

It is a left side view of the motorcycle in embodiment of this invention. It is sectional drawing of the transmission and change mechanism of the above-mentioned motorcycle. It is a schematic explanatory drawing of the clutch actuation system including a clutch actuator. It is a block diagram of a speed change system. It is explanatory drawing which shows the transition of a clutch control mode. It is a graph which shows the outline of the slipper control at the time of deceleration of the motorcycle. It is a graph which shows the time change of the control parameter of the slipper control at the time of deceleration. It is a graph which shows the time change of the control parameter of the slipper control at the time of deceleration. It is explanatory drawing which shows the vehicle body condition at the time of deceleration of the said motorcycle. It is a graph which shows the outline of the wheel speed correction of the slipper control at the time of deceleration. It is an operation explanatory view of the 2nd Embodiment, and is the cross-sectional view which shows the change between the ground contact angle of a front wheel, and a ground contact point. It is an operation explanatory view of the 2nd Embodiment, and is the cross-sectional view which shows the change between the ground contact angle of a rear wheel, and a ground contact point. It is an operation explanatory diagram of the 2nd Embodiment, and is a graph which shows the correlation between the circumference change rate ratio of the front and rear wheels, and a bank angle. It is an operation explanatory diagram of the 2nd Embodiment, and is the explanatory diagram which shows the control intervention pattern at the time of sudden deceleration from the vehicle body upright state. It is an operation explanatory diagram of the 2nd Embodiment, and is the explanatory diagram which shows the control intervention pattern at the time of sudden deceleration from the vehicle body bank state. It is a timing chart of the slipper control at the time of deceleration of the vehicle body bank state in the second embodiment. It is a timing chart which shows the wheel speed correction condition of the slipper control at the time of deceleration of the vehicle body bank state in the 2nd Embodiment. It is a timing chart which shows the intervention condition of the slipper control at the time of deceleration of the vehicle body bank state in the 2nd Embodiment. It is a graph which shows the intervention area of the slipper control at the time of deceleration of the vehicle body bank state in the 2nd Embodiment, and is the graph which the vertical axis is deceleration, and the horizontal axis is a bank angle. It is a flowchart which shows the process performed by the ECU at the time of determining whether or not to shift to the wheel speed correction in the 1st and 2nd embodiments. It is a flowchart which shows the process performed by the ECU at the time of determining whether or not to execute the slipper control in the 1st and 2nd embodiments. It is a flowchart which shows the process performed by the ECU at the time of determining whether or not the slipper control in the 1st and 2nd embodiments is terminated.

Hereinafter, the first embodiment of the present invention will be described with reference to the drawings. The orientations of the front, rear, left, right, etc. in the following description are the same as the orientations in the vehicle described below unless otherwise specified. Further, in the appropriate place in the figure used in the following description, an arrow FR indicating the front of the vehicle, an arrow LH indicating the left side of the vehicle, and an arrow UP indicating the upper part of the vehicle are shown.

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

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

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, the front seat 19 and the rear seat cover 19a are supported side by side in the front-rear direction. The periphery of the seat frame 9 is covered with a rear cowl 9a. Below the left and right main tubes 7, a power unit PU, which is the prime mover of the motorcycle 1, is suspended. The power unit PU is linked to the rear wheel 12 via, for example, a chain type transmission mechanism.

The power unit PU integrally has an engine (internal combustion engine, prime mover) 13 located on the front side thereof and a transmission 21 located on the rear side thereof. The engine 13 is, for example, a multi-cylinder engine in which the rotation axis of the crankshaft 14 is aligned in the left-right direction (vehicle width direction). The engine 13 has a cylinder 16 standing above the front portion of the crankcase 15. The rear portion of the crankcase 15 is a transmission case 17 that houses 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 straddling both shafts 22, 23. The counter shaft 23 constitutes the output shaft of the transmission 21 and thus the power unit PU. The end portion of the counter shaft 23 projects to the left side of the rear portion 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 corresponding to the number of gears supported by both shafts 22 and 23, respectively. The transmission 21 is of a constant meshing type in which the corresponding gear pairs of the transmission gear group 24 are always meshed between the shafts 22 and 23. The plurality of gears supported by the shafts 22 and 23 are classified into a free gear that can rotate with respect to the corresponding shaft and a slide gear (shifter) that is spline-fitted to the corresponding shaft. One of the free gear and the slide gear is provided with a dog that is convex in the axial direction, and the other is provided with a slot that is concave in the axial direction so as to engage the dog. That is, the transmission 21 is a so-called dog mission.

The main shaft 22 and the counter shaft 23 of the transmission 21 are arranged side by side behind the crankshaft 14. 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, which is a so-called normal open clutch. That is, the clutch device 26 is in a connected state in which power can be transmitted by supplying hydraulic pressure from the clutch actuator 50, and returns to a disconnected state in which power cannot be transmitted when the hydraulic pressure supply from the clutch actuator 50 is exhausted.

The rotational power of the crankshaft 14 is transmitted to the main shaft 22 via the clutch device 26, and is transmitted from the main shaft 22 to the counter shaft 23 via any gear pair of the transmission gear group 24. The drive sprocket 27 of the chain type transmission mechanism is attached to the left end portion of the counter shaft 23 that protrudes to the left side of the rear portion of the crankcase 15.
The clutch device 26 includes a back torque limiter (not shown). The back torque limiter mechanically reduces the clutch capacity when a back torque exceeding a specified value acts on the cam mechanism provided in the clutch device 26.

A change mechanism 25 for switching gear pairs of the transmission gear group 24 is housed above the rear of the transmission 21. The change mechanism 25 operates a plurality of shift forks 36a according to the pattern of the lead groove formed on the outer periphery thereof by the rotation of the hollow cylindrical shift drum 36 parallel to both the shafts 22 and 23, and the transmission gear group 24 The gear pair used for power transmission between the shafts 22 and 23 in the above is switched.

The change mechanism 25 has a shift spindle 31 parallel to the shift drum 36. When the shift spindle 31 is rotated, the shift arm 31a fixed to the shift spindle 31 rotates the shift drum 36, and the shift fork 36a is axially moved according to the pattern of the lead groove to move the power in the shift gear group 24. Switch transmissible gear pairs (ie, switch gears).

With reference to FIG. 1, the shift spindle 31 projects the shaft outer portion 31b to the outside (left side) 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 detecting means) is coaxially attached to the shaft outer portion 31b of the shift spindle 31. A swing lever 33 is attached to the shaft outer portion 31b (or the rotation shaft of the shift load sensor 42) of the shift spindle 31. The swing lever 33 extends rearward from the base end portion 33a clamped and fixed to the shift spindle 31 (or the rotating shaft), and the upper end portion of the link rod 34 swings at the tip end portion 33b via the upper ball joint 34a. It is connected freely. The lower end of the link rod 34 is swingably connected to the shift pedal 32 operated by the driver via a lower ball joint (not shown).

As shown in FIG. 1, the front end portion of the shift pedal 32 is supported on the lower portion of the crankcase 15 so as to be swingable up and down via a shaft along the left-right direction. A pedal portion for hanging the toes of the driver mounted on the step 32a is provided at the rear end portion of the shift pedal 32, and a lower end portion of the link rod 34 is connected to the front-rear middle portion of the shift pedal 32.

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

<Speed change system>
As shown in FIG. 4, the speed change system includes a clutch actuator 50, an ECU 60 (Electronic Control Unit), and various sensors 41 to 45.
The ECU 60 has detection information from a gear position sensor 41 that detects a shift stage from the rotation angle of the shift drum 36, a shift load sensor 42 (for example, a torque sensor) that detects an operation torque input to the shift spindle 31, and throttle opening. Based on various vehicle state detection information from the degree sensor 43, the vehicle speed sensor 44, the engine rotation speed sensor 45, etc., the operation of the clutch actuator 50 is controlled, and the operation of the ignition device 46 and the fuel injection device 47 is controlled.
The vehicle speed sensor 44 includes a front wheel speed sensor 44f that detects the rotation speed of the front wheels 2, and a rear wheel speed sensor 44r that detects the rotation speed of the rear wheels 12. The engine speed is controlled by a throttle by wire (TBW) including a throttle valve and an accelerator grip.

Detection information from the hydraulic sensors 57 and 58, which will be described later, the shift operation detection switch (shift neutral switch) 48, and the gyro sensor 49 that detects the condition (movement) of the vehicle body is also input to the ECU 60. The gyro sensor 49 is an IMU (inertial measurement unit), and outputs a signal corresponding to an acceleration component in the detection direction to the ECU 60. The gyro sensor 49 may be built in the ECU 60.
Further, the ECU 60 includes a hydraulic pressure control unit 61 and a wheel speed difference determination unit (rear lift detection unit) 62. The hydraulic control unit 61 includes a slipper control unit 61a. The wheel speed difference determination unit 62 includes a wheel speed correction unit 62a. Reference numeral 60A in the figure indicates the clutch control device of the first embodiment.

With reference to FIG. 3, the clutch actuator 50 can control the hydraulic pressure for connecting and disconnecting the clutch device 26 by controlling the operation by the ECU 60. The clutch actuator 50 includes an electric motor 52 as a drive source (hereinafter, simply referred to as a motor 52) 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 supply / discharge port 50p.
The ECU 60 calculates a target value (target hydraulic pressure) of the hydraulic pressure supplied to the slave cylinder 28 for engaging and disengaging the clutch device 26 based on a preset calculation program, and the slave cylinder detected by the downstream hydraulic sensor 58. The clutch control unit 50A is controlled so that the hydraulic pressure on the 28 side (slave hydraulic pressure) approaches the target hydraulic pressure.

The master cylinder 51 strokes the piston 51b in the cylinder body 51a by driving the motor 52 so that the hydraulic oil in the cylinder body 51a can be supplied and discharged to the slave cylinder 28. In the figure, reference numeral 55 indicates a conversion mechanism as a ball screw mechanism, reference numeral 54 indicates a transmission mechanism straddling the motor 52 and the conversion mechanism 55, and reference numeral 51e indicates a reservoir connected to the master cylinder 51.

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 oil supply / exhaust passage) 53 m extending from the master cylinder 51 to the clutch device 26 side (slave cylinder 28 side). is doing. The 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 in the direction from the upstream side to the downstream side. On the upstream side of the solenoid valve 56, an upstream oil pressure sensor 57 for detecting the oil pressure of the upstream oil passage 53a is provided. On the downstream side of the solenoid valve 56, a downstream hydraulic pressure sensor 58 for detecting the hydraulic pressure of the downstream oil pressure passage 53b is provided.

As shown in FIG. 1, the clutch control unit 50A is housed in, for example, 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 a hydraulic pipe 53e (see FIG. 3).

As shown in FIG. 2, the slave cylinder 28 is coaxially arranged on the left side of the main shaft 22. The slave cylinder 28 presses the push rod 28a penetrating the inside of the main shaft 22 to the right when the hydraulic pressure is supplied from the clutch actuator 50. By pressing the push rod 28a to the right, the slave cylinder 28 operates the clutch device 26 to the connected state via the push rod 28a. When the hydraulic pressure supply is exhausted, the slave cylinder 28 releases the pressure of 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 the hydraulic pressure supply, but the electric power is consumed by that amount. 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 the 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 (recharges by the leak), and energy consumption is suppressed.

<Clutch control mode>
As shown in FIG. 5, the clutch control device 60A of the first embodiment has three types of clutch control modes. The clutch control mode is a clutch control mode changeover switch 59 (FIG. 4) between three modes: an auto mode M1 for automatic control, a manual mode M2 for manual operation, and a manual intervention mode M3 for temporary manual operation. (See) and the clutch lever 4b (see FIG. 1) are operated to make appropriate transitions. The target including the manual mode M2 and the manual intervention mode M3 is referred to as a manual M2A. The clutch control device 60A also functions as a clutch-by-wire system in which the clutch lever 4b and the clutch device 26 are electrically connected.

The auto mode M1 is a mode in which the clutch device 26 is controlled by calculating the clutch capacity suitable for the traveling state by 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 in response to a clutch operation instruction by the occupant. The manual intervention mode M3 is a temporary manual operation mode in which the clutch operation instruction from the occupant is received during the auto mode M1, the clutch capacity is calculated from the clutch operation instruction, and the clutch device 26 is controlled. It is set to return to the auto mode M1 when the occupant stops (completely releases) the operation of the clutch lever 4b during the manual intervention mode M3.

The clutch control device 60A of the first embodiment drives an oil pump (not shown) by the rotational driving force of the engine 13 to generate clutch control hydraulic pressure. Therefore, when the system is started, the clutch control device 60A starts control from the clutch off state (disengagement state) in the auto mode M1. Further, since the clutch control device 60A does not require a clutch operation when the engine 13 is stopped, it is set to return to the clutch off in the auto mode M1.

The auto mode M1 basically automatically controls the clutch, and enables the motorcycle 1 to travel without lever operation. In the auto mode M1, the clutch capacity is controlled by the throttle opening, the engine speed, the vehicle speed, and the shift sensor output. As a result, the motorcycle 1 can be started without stalling only by the throttle operation, and the speed can be changed only by the shift operation. However, the clutch device 26 may be automatically disengaged at an extremely low speed equivalent to idling. Further, in the auto mode M1, the manual intervention mode M3 is set by grasping the clutch lever 4b, and the clutch device 26 can be arbitrarily disengaged.

On the other hand, in the manual mode M2, the clutch capacity is controlled by the lever operation by the occupant. The auto 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. The clutch control device 60A may include an indicator indicating that the lever operation is effective at the time of transition to the manual system M2A (manual mode M2 or manual intervention mode M3).

In the manual mode M2, the clutch is basically controlled manually, and the clutch hydraulic pressure can be controlled according to the operating angle of the clutch lever 4b. As a result, the engagement and disengagement of the clutch device 26 can be controlled at the will of the occupant, and the clutch device 26 can be connected and traveled even at an extremely low speed equivalent to idling. However, depending on the lever operation, the engine may stall, and automatic starting by only throttle operation 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 by manually operating the clutch lever 4b, the manual operation is temporarily intervened in the automatic control of the clutch device 26. It is possible (manual intervention mode M3).

<Slipper control during deceleration>
Next, the slipper control during deceleration of the motorcycle 1 will be described.
With reference to FIG. 6, in the motorcycle 1, during sudden deceleration such as when entering a corner in a race, the rear contact load Mg2 (rear wheel contact load) is released (becomes too small) between the front and rear wheels 2 and 12. A wheel speed difference D occurs.

Also referring to FIG. 8, at the time of sudden deceleration of the motorcycle 1, the front ground contact load Mg1 (front wheel ground contact load) increases, and the front grip force Mg3 becomes the main deceleration. That is, when the inertial force Fb1 due to deceleration acts on the center of gravity G of the vehicle body, the component force Fb2 of this inertial force Fb1 acts toward the front and upper side with reference to the front contact position Pg1, and the front contact position Pg1 is used as a reference for the vehicle body. Generate a moment. As a result, the rear ground contact load Mg2 is released (decreased), and the rear grip force Mg4 is reduced. Depending on the magnitude of the vehicle body deceleration, the rear ground contact load Mg2 becomes zero, and the rear wheel 12 floats from the road surface (rear grip force Mg4 becomes zero).

If the rear wheel 12 floats during deceleration, the rotational speed of the rear wheel 12 suddenly decelerates due to the influence of the engine brake. Even if the rear wheel 12 does not float, the rear ground contact load Mg2 becomes diluted, the rear grip force Mg4 decreases, and the rear wheel 12 slips due to the engine brake. As a result, the rotation speed of the rear wheels 12 (rear wheel speed Vr) is lower than the rotation speed of the front wheels 2 (front wheel speed Vf). Hereinafter, the rear lift state includes a state in which the rear wheel 12 floats from the road surface and a state in which the rear contact load Mg2 is lowered to the extent that a wheel speed difference D between the front and rear wheels 2 and 12 occurs.

Depending on the rear lift state, vehicle body behavior such as hopping and snakes that accompanies a decrease in the ground contact property (rear wheel ground contact property) of the rear wheel 12 occurs. In the rear lift state, the back torque exceeding the specified value does not act on the clutch device 26. Therefore, the back torque limiter of the clutch device 26 does not operate, and the vehicle body behavior due to the deterioration of the rear wheel ground contact cannot be eliminated. On the other hand, there is a problem in responsiveness and controllability in engine brake control by fuel injection of the engine 13 and opening / closing of the throttle valve.

In the first embodiment, it is determined whether or not the rear lift state is reached at the time of sudden deceleration corresponding to the braking of the race. Then, based on this determination, the clutch capacity is reduced by controlling the automatic clutch system (slipper control during deceleration). As a result, the occurrence of hopping and snakes is suppressed, and the rear wheel ground contact property is ensured. Since it is determined whether or not the rear wheel 12 is floating and the clutch capacity is reduced, it is possible to prevent the engine brake from being inadvertently lowered as compared with the conventional technique, and to secure an appropriate engine brake. Further, the responsiveness and controllability at the time of control are better than those of engine brake control by engine control.

The determination of whether or not the vehicle is in the rear lift state (determination of whether or not the rear contact load Mg2 is too small) is made by the wheel speed difference determination unit 62 of the ECU 60. When the difference between the front and rear wheel speeds Vf and Vr (front and rear wheel speed difference D) becomes equal to or greater than the specified value when the brake is turned on, the wheel speed difference determination unit 62 determines that the rear lift state is due to sudden deceleration. In other words, the wheel speed difference determination unit 62 detects that the rear lift state is due to sudden deceleration based on the detection signal of the brake switch and the detection signals of the front and rear wheel speed sensors 44f and 44r.

When the wheel speed difference determination unit 62 detects (determines) that the wheel speed difference determination unit 62 is in the rear lift state, the slipper control unit 61a of the hydraulic pressure control unit 61 of the ECU 60 controls the clutch device 26 with slippers. The slipper control unit 61a calculates a target value (target hydraulic pressure) of the hydraulic pressure supplied to the slave cylinder 28 based on a preset calculation program, and controls the clutch control unit 50A. The slipper control is a control for lowering the clutch capacity of the clutch device 26 (control for reducing the target hydraulic pressure).

The slipper control causes the clutch device 26 to slip, similar to the back torque limiter. The slipper control causes the clutch device 26 to generate a clutch differential rotation (clutch slip). The slipper control releases the back torque acting on the clutch device 26 and suppresses the engine brake acting on the rear wheels 12. The slipper control suppresses vehicle body behavior such as hopping and snaking that accompanies a decrease in the ground contact property (rear wheel ground contact property) of the rear wheel 12.

With reference to FIG. 6, in the motorcycle 1, when the two wheels 2 and 12 are in contact with each other and the rear wheels 12 are suddenly decelerated to the extent that the rear wheels 12 are lifted, the rear wheel speed Vr is greatly tilted with respect to the front wheel speed Vf. Decreases with. That is, when the vehicle is decelerated to such an extent that the rear wheels 12 float, the rear wheel speed Vr is lower than the front wheel speed Vf. The slope of the line indicating the front and rear wheel speeds Vf and Vr in the graph of FIG. 6 is defined as the deceleration Af and Ar of each of the front and rear wheels 2 and 12, and the difference between the front and rear wheel speeds Vf and Vr at the same timing is defined as the front and rear wheel speed difference D. do. The clutch device 26 is in a engaged state in which the clutch capacity is maintained at the maximum value until the timing tm1 at which the front-rear wheel speed difference D becomes the predetermined first specified value K1 (difference). At this time, the clutch device 26 changes while the clutch differential rotation is substantially zero. The rear wheel 12 is lifted in the middle of this sudden deceleration.

The clutch device 26 starts deceleration control (slipper control) at the timing tm1 at which the front-rear wheel speed difference D becomes the first specified value K1. The clutch device 26 is in a state where the clutch capacity is reduced after the timing tm1. That is, the clutch device 26 is in a half-clutch state after the timing tm1 and generates a clutch difference rotation (clutch slip) when there is no slipper control (line Dc'in the figure) (line Dc in the figure). Then, the decrease (deceleration Ar) of the rear wheel speed Vr with slipper control becomes gradual with respect to the rear wheel speed Vr'without slipper control.
When the rear wheel 12 touches the ground (timing tm2), the rear wheel speed Vr'without slipper control is greatly disturbed, whereas the rear wheel speed Vr with slipper control is less disturbed because clutch slip is allowed. Will be. Further, while the clutch differential rotation Dc'without slipper control is disturbed, the clutch differential rotation Dc with slipper control is allowed to increase, so that the disturbance is suppressed.
Eventually, the rear wheel speed Vr approaches the front wheel speed Vf. When the rear wheel speed Vr approaches the front wheel speed Vf, the speed difference between the rear wheels 12 and the road surface becomes small, and hopping and snakes when the rear wheels 12 touch the ground are suppressed. Further, since the clutch capacity is reduced, the input of the back torque from the rear wheel 12 becomes small even if there is a speed difference with the road surface. As a result, the vehicle body behavior due to the deterioration of the ground contact property (rear wheel ground contact property) of the rear wheel 12 is suppressed.

In the slipper control, the front-rear wheel speed difference D is reduced to less than the predetermined second specified value K2, and the vehicle speed deceleration (based on the deceleration Af of the front wheel 2) is reduced to less than the predetermined third specified value K3. Continue until the timing tm3. The second specified value K2 is a value at which the front-rear wheel speed difference D is expected to converge to zero. The third specified value K3 is a value that is expected to eliminate the rear lift state. In FIG. 6, the timing tm1 is reached after the rear wheel lift is generated, and the timing tm3 is reached after the rear wheel 12 is regrounded.

At the timing tm3 when the deceleration of the vehicle speed decreases and the difference between the front and rear wheel speeds Vf and Vr is about to converge to 0, the slipper control ends and the clutch device 26 is reconnected (normal control in the above-mentioned engaged state). Will be done. By reconnecting the clutch device 26, the clutch differential rotation is absorbed and converges to zero. That is, the clutch device 26 returns to the normal connection state.

The rear wheel speed Vr'when the slipper control is not performed has a larger front / rear wheel speed difference D than the rear wheel speed Vr when the slipper control is performed after the timing tm1 has passed. If the floating rear wheel 12 touches the road surface with a speed difference while the front-rear wheel speed difference D is large, vehicle body behavior such as hopping is likely to occur (region R1 in the figure), and re-acceleration after deceleration. Will affect.

In the first embodiment, since the rear wheel ground contact property is improved by slipper control even during sudden deceleration, the vehicle body stability during deceleration is improved and the vehicle body controllability is improved.
Compared to a mechanical back torque limiter, it is possible to generate clutch slip even with a small back torque. Therefore, even when the ground contact load of the rear wheel 12 is low, the rear wheel ground contact property is improved and the occurrence of hopping and the like is suppressed. For example, in racing use, the behavior of the vehicle body is stabilized even when entering a corner while decelerating suddenly, so it is easy to open the throttle even during cornering after deceleration, which contributes to improved acceleration at the start of a corner.

With reference to FIG. 7A, when the motorcycle 1 is decelerated, the TH opening degree and the C-axis (crankshaft 14) torque are first reduced by throttle off. After that, when the brake switch is turned on (brake operation), the vehicle body deceleration is increased and the front and rear wheel speeds Vf and Vr are different from each other by a specified value or more, so that the slipper control is started (region R2). By slipper control, the target value (target hydraulic pressure) of the hydraulic pressure supplied to the slave cylinder 28 and the actual slave hydraulic pressure (control hydraulic pressure) are reduced to the equivalent of a half-clutch. As a result, the occurrence of hopping and the like during deceleration is suppressed (region R3), and since the vehicle body behavior is stable even during cornering after deceleration, the throttle can be opened early (region R4) and the vehicle speed is also increased. In the figure, "Ne" indicates the engine speed.

In the comparative example in the case where the slipper control is not performed with reference to FIG. 7B, hopping or the like occurs (region R5) as can be seen from the disturbance of the C-axis torque during deceleration. Due to this effect, the throttle cannot be opened during cornering after deceleration (region R6), and the increase in vehicle speed is reduced as compared with the case where slipper control is performed.

Frequent slipper control intervention is not preferred in terms of engine braking utilization, system load reduction, and rider discomfort. In order to use the engine brake as much as possible and reduce the rider's discomfort, we want to reduce the frequency of slipper control intervention. That is, it is preferable that the slipper control is intervened after the wheel speed difference actually occurs.
In the first embodiment, the specification is such that the vehicle body posture, front and rear wheel speeds Vf, Vr, and vehicle body acceleration (deceleration) are detected, and the clutch capacity is controlled based on these detection information.

For example, as the intervention conditions for slipper control during deceleration, all of the following conditions are satisfied.
First, it is a condition that the vehicle body deceleration (absolute value) is the third specified value K3 or more (for example, the vehicle speed fluctuation per unit time is set to be 1% or more of the current vehicle speed). As a result, it is detected that the rear wheel 12 is in a sudden deceleration such as floating. On the other hand, the bank state and the mere rear lock state are excluded.
Secondly, it is a condition that the front-rear slip ratio (front wheel speed Vf / rear wheel speed Vr) is equal to or higher than a predetermined fourth specified value.
Thirdly, it is a condition that the front-rear slip amount (front wheel speed Vf-rear wheel speed Vr) is equal to or more than the first specified value K1.
That is, in addition to the front-rear slip amount (front-rear wheel speed difference D) being the first specified value K1 or more, it was also added that the front-rear slip ratio was the fourth specified value or more. By making an intervention judgment of slipper control (judgment that the rear wheel 12 is slipping, in other words, slip judgment) using these two types of parameters, it is possible to more accurately judge that the rear wheel 12 has floated. ..

The slip determination may be performed according to one of the front-rear slip ratio and the front-rear slip amount. That is, the slip determination may be performed according to at least one of the front-rear slip ratio and the front-rear slip amount. Hereinafter, the front-back slip ratio may be referred to as the first parameter Pa1, and the front-back slip amount may be referred to as the second parameter Pa2.

As a result of diligent examination by the applicant as to which of the front-rear slip ratio and the front-rear slip amount is suitable for slip determination, the front-rear slip ratio is high when the vehicle speed (vehicle speed) is high, and the front-rear slip ratio is low when the vehicle speed (vehicle speed) is low. It was found that the amount of slip before and after is suitable for the intervention judgment of slipper control.
For example, when the vehicle speed is equal to or higher than the first vehicle speed (for example, 70 km / h), the slipper control is configured to intervene according to the front-rear slip rate. Further, when the vehicle speed is less than the first vehicle speed and more than the second vehicle speed (for example, 50 km / h), the slipper control is configured to intervene according to the front-rear slip amount.

For example, the slip determination condition when the vehicle speed is high (at a high speed of 70 km / h or more) is that all of the following conditions are satisfied.
First, it is a condition that the vehicle body deceleration (absolute value) is the third specified value K3 or more.
The second condition is that the front-rear slip ratio (front wheel speed Vf / rear wheel speed Vr) is equal to or higher than the fourth specified value (for example, the front wheel speed Vf is set to increase by 3% of the rear wheel speed Vr). do.

Further, when the vehicle speed is not as high as that at the high speed (at a semi-high speed of 50 km / h or more), all of the following conditions are satisfied.
First, it is a condition that the vehicle body deceleration (absolute value) is the third specified value K3 or more.
Secondly, it is a condition that the front-rear slip amount (front-rear wheel speed difference D) is equal to or higher than the first specified value K1 (for example, the front wheel speed Vf is set to increase by 5 km / h of the rear wheel speed Vr).

After the slip determination, for example, when the front-rear slip ratio becomes less than the fourth specified value or the front-rear slip amount becomes less than the first specified value K1, the intervention of the slipper control is terminated. That is, the intervention of the slipper control is terminated when the delay of the rear wheel speed Vr (and thus the rear lift state) is resolved. Further, the slipper control intervention is terminated even when the throttle of the engine 13 opens (there is a request for acceleration of the motorcycle 1) or the vehicle speed drops below 50 km / h, which is the semi-high speed.

<Wheel speed correction control>
Next, the wheel speed correction control in the motorcycle 1 will be described.
One of the problems of the slip determination is to reflect (follow) the change in the circumference of the tire in the control parameter. The circumference of the front and rear wheels 2 and 12 changes individually due to the brand, air pressure, wear, etc., and the influence of centrifugal force. Therefore, even if the front and rear wheels 2 and 12 rotate without slipping on the road surface, the front and rear wheel speed difference D may be detected as the tire circumference changes. Since it is difficult to measure (monitor) the circumference of the tire, the front and rear wheel speeds Vf and Vr during traveling are corrected (learned).

In the first embodiment, when the slipper control is performed, the wheel speed correction unit 62a of the wheel speed difference determination unit 62 of the ECU 60 corrects the wheel speed. The wheel speed correction unit 62a corrects the wheel speed based on a preset calculation program. Slipper control for the clutch device 26 is performed based on the wheel speed obtained by this correction.

In the wheel speed correction method of the first embodiment, the wheel speed change rate (rear wheel speed change rate Vrc, which will be described later) in which the change amount of the wheel speed is made dimensionless is utilized. This makes it possible to detect the wheel speed difference D ignoring the difference in the circumference of the front and rear tires.
Specifically, as shown in FIG. 9, first, a point (specific time point) at which the true front / rear wheel speeds Vf and Vr are considered to be the same is defined as the initial point IP. "The true front and rear wheel speeds Vf and Vr are the same" means that the front wheel speed Vf, which is the basis of the vehicle speed (vehicle speed), and the rear wheel speed Vr, which is corrected later, are the same.

When the peripheral lengths of the front and rear tires are different from each other, the front and rear wheel speeds Vf and Vr that actually correspond to the same vehicle speed are apparently different front and rear wheel speeds Vf and Vr. If the true front and rear wheel speeds Vf and Vr are the same in consideration of the difference in the circumference of the front and rear tires, it is considered that the rate of change in the wheel speeds is also the same. Therefore, by adding a correction to the front wheel speed Vf, the corrected wheel speed Vrh that can match the front wheel speed Vf is obtained, and the difference between the corrected wheel speed Vrh and the front wheel speed Vf is used for the slip determination.

The rear wheel speed change rate Vrc (t) for each wheel speed measurement time point is calculated by the following equation 1.
Rear wheel speed change rate Vrc (t) = (Vr (t-α) -Vr (t)) / Vr (t) ... Equation 1 (Vr (t) is the rear wheel speed Vr at each measurement time point)

Time α is the measurement cycle. As the initial point IP, the timing tm4 at the moment when the vehicle is in the decelerated state and the tire rotations of the front and rear wheels 2 and 12 are stable is used. This timing tm4 is, for example, the timing at which a time α of about 80 to 100 msec has elapsed after the throttle valve is turned off (fully closed). The calculation of the corrected wheel speed Vrh is started from this timing tm4 (wheel speed correction start permission).

The initial point IP includes the condition that the vehicle body is upright in the roll direction. The upright state includes not only an upright position in which the left and right center surfaces of the vehicle body stand vertically, but also a range in which the change in tire circumference during determination is small (a range in which the change in tire curvature is small). For example, it includes a range in which the vehicle body is within a bank angle of ± 20 deg from the upright position. Under this condition, the initial point IP is detected as a state in which the motorcycle 1 is stably traveling. It should be noted that the circumference of the tire contact point changes during the banking of the vehicle body, and the inner ring difference also occurs during cornering, so that it is not suitable for determining the front-rear wheel speed difference D.

Based on the front wheel speed Vf (0) at the moment of the initial point IP (t = 0), the corrected wheel speed (front wheel conversion rear wheel speed) Vrh (t) is calculated (the following equations 2 and 3). reference).
Corrected wheel speed Vrh (t1) = Vf (0) x Vrc (0) + Vf (0) ... Equation 2 Corrected wheel speed Vrh (t2) = Vf (t1) x Vrc (t1) + Vf (t1).・ ・ Equation 3 (same below)

Then, the ratio between the front wheel speed Vf and the corrected rear wheel speed Vrh is calculated as the front / rear wheel speed ratio corrected for the difference in the peripheral lengths of the front and rear tires (formula 4 below), and this is used as a determination value for slipper control.
Front / rear wheel speed ratio = Vf (t) / corrected wheel speed Vrh (t) ... Equation 4
Hereinafter, the "front-rear wheel speed ratio" may be simply referred to as the "wheel speed ratio".

The initial condition (condition for starting the wheel speed correction calculation) corresponds to the state in which the motorcycle 1 is in the above-mentioned upright state, the front and rear wheels 2 and 12 are in the non-slip state, and the throttle is in the closed state. ..
Specifically, all of the following conditions are satisfied.
1. 1. Bank angle <20 °
2. 2. Body deceleration <Third specified value K3
3.0.93 <Front wheel speed Vf / Rear wheel speed Vr <1.07
4. Throttle valve opening <1 °
5. Vehicle speed> 50km / h
"Front wheel speed Vf / rear wheel speed Vr <1" corresponds to "front wheel speed Vf = rear wheel speed Vr". Instead of this condition, "front wheel speed Vf-rear wheel speed Vr <initial specified value" may be a condition. The "initial specified value" is a predetermined threshold value, and the standard is 0 (front wheel speed Vf = rear wheel speed Vr).

After the start of the wheel speed correction calculation, the condition for permitting (starting) slipper control (half-clutch control) during deceleration is that the motorcycle 1 is in a sudden deceleration state, and during this sudden deceleration (rear grip force) <(engine brake). Therefore, a difference is generated between the front and rear wheel speeds Vf and Vr.
Specifically, all of the following conditions are satisfied.
1. 1. Body deceleration> Third specified value K3 (the greater the deceleration, the suddener the deceleration)
2. 2. Front wheel speed Vf / corrected wheel speed Vrh (front-rear slip rate)> Fourth specified value (standard is 1 (front wheel speed Vf = corrected wheel speed Vrh), the larger the front-rear slip rate, the larger the rear wheel slip)
3. 3. | Front wheel speed Vf-Corrected wheel speed Vrh | (Front and rear slip amount)> First specified value K1 (Standard is 0 (Front wheel speed Vf = Corrected wheel speed Vrh), The larger the front and rear slip amount, the larger the rear wheel slip)

The front-rear slip ratio can be greater than or equal to the fourth specified value when (rear grip force) <(engine brake) and a front-rear wheel speed difference D occurs. When the front-back slip ratio is equal to or higher than the fourth specified value, slipper control intervention may be required. By considering not only the front-back slip ratio but also the front-back slip amount, it is possible to more accurately determine the situation in which slipper control intervention is required.

After the vehicle body deceleration increases from the 0 level to the third specified value K3, when at least one of the front-rear slip ratio of the fourth specified value or more and the front-rear slip amount of the first specified value K1 or more is satisfied, the timer count in the ECU 60. To start. When this count exceeds the specified time, slipper control during deceleration is started. By setting the condition that the control condition continues for a specified time, momentary slip and the like are excluded.

The condition for completing the slipper control during deceleration is that the rear wheel slip is small and the clutch differential rotation is less than the predetermined fifth specified value.
Specifically, all of the following conditions are satisfied.
1. 1. Front-rear slip rate <fourth specified value, or front-rear slip amount <first specified value K1 (both correspond to front wheel speed Vf = corrected wheel speed Vrh)
2. 2. ｜ Clutch differential rotation ｜ ＜ Fifth specified value (equivalent to 0, to prevent shock when clutch is engaged)
When these conditions are satisfied, the slipper control during deceleration ends, the clutch engagement starts, and the wheel speed correction calculation ends.

As described above, the clutch control device 60A of the motorcycle 1 according to the first embodiment includes the rear wheel 12 which is a driving wheel, the front wheel 2 which is a driven wheel, the engine 13 for traveling, and the engine 13. The clutch device 26 for disconnecting and connecting the power transmission to and from the rear wheel 12, the clutch actuator 50 for driving the clutch device 26 to change the clutch capacity, and the control target value (target hydraulic pressure) for the clutch capacity are calculated. The ECU 60 is provided with a slipper control that reduces the clutch capacity when it detects that the rear wheel 12 is in a predetermined contact load reduction state (rear lift state) when the motorcycle 1 is decelerating. I do.
Specifically, in the ECU 60, the rear wheel speed Vr, which is the rotation speed of the rear wheel 12, is a predetermined difference (first specified value K1) with respect to the front wheel speed Vf, which is the rotation speed of the front wheel 2. ) Is exceeded, and it is determined that the rear wheel 12 is in the ground contact load reduced state.
According to this configuration, it is possible to perform slipper control to reduce the clutch capacity when it is detected that the ground contact load is lowered to the extent that the rear wheels 12 float when the motorcycle 1 is decelerated. As a result, it is possible to secure an appropriate engine brake during normal driving in which the ground contact load of the rear wheel 12 is secured, and to shift to slipper control during sudden deceleration such that the rear wheel 12 floats. Since the engine brake of the rear wheel 12 is weakened by this slipper control, the occurrence of hopping and snakes due to the engine brake when the ground contact load of the rear wheel 12 is released can be suppressed. Therefore, it is possible to secure the ground contact property of the rear wheels when the motorcycle 1 is decelerated.
For example, in the racing use of the motorcycle 1, when entering a corner while suddenly decelerating, the rider can easily concentrate on the cornering, which can contribute to the transition to smooth acceleration at the start of the corner. Further, the clutch capacity can be made variable as compared with the mechanical back torque limiter.

In the clutch control device 60A of the motorcycle 1, the ECU 60 uses the corrected rear wheel speed Vr obtained by correcting the front wheel speed Vf as the rear wheel speed Vr to be compared with the front wheel speed Vf.
According to this configuration, the actual front and rear wheel speeds Vf and Vr are affected not only by the difference in the tire outer diameters of the front and rear wheels 2 and 12, but also by the change in the tire circumference. On the other hand, by calculating the corrected wheel speed Vrh for comparison based on the front wheel speed Vf and comparing the corrected wheel speed Vrh with the front wheel speed Vf, it is affected by the change in the tire circumference. Without this, it is possible to accurately detect a decrease in the rear wheel speed Vr and prevent an inadvertent decrease in clutch capacity (engine brake decrease).

In the clutch control device 60A of the motorcycle 1, the corrected wheel speed Vrh is obtained by adding the change amount of the rear wheel speed Vr at the same point to the front wheel speed Vf at the time of wheel speed correction.
According to this configuration, since the wheel speed is corrected by adding the amount of change in the rear wheel speed Vr to the front wheel speed Vf, the correction control can be simplified and the system load can be suppressed.

In the clutch control device 60A of the motorcycle 1, the motorcycle 1 is in an upright posture, the difference between the front and rear wheel speeds Vf and Vr is less than a predetermined initial specified value, and the throttle of the engine 13 is closed. Wheel speed correction is started from the time point (initial point IP).
According to this configuration, the motorcycle 1 is in an upright posture and the throttle of the engine 13 is closed, and the difference between the front and rear wheel speeds Vf and Vr is less than the initial specified value set in advance as a value without rear wheel slip. By using a certain state as a reference for wheel speed correction, wheel speed correction can be performed with high accuracy.

In the clutch control device 60A of the motorcycle 1, the value obtained by dividing the front wheel speed Vf by the corrected wheel speed Vrh is set as the first parameter Pa1 (front-rear slip ratio), and the front wheel speed Vf is divided into the corrected wheel speed. The value obtained by subtracting Vrh is defined as the second parameter Pa2 (front-back slip amount), and the slipper control is intervened according to at least one of the first parameter Pa1 and the second parameter Pa2.
According to this configuration, by selecting an appropriate value from two types of parameters and making an intervention judgment for slipper control (judgment that the rear wheel 12 is slipping, in other words, slip judgment), the minimum necessary. Slipper control can be performed at the frequency of.

In the clutch control device 60A of the motorcycle 1, when the vehicle speed is equal to or higher than the first vehicle speed, the slipper control is intervened according to the first parameter Pa1, and the vehicle speed is less than the first vehicle speed and the second vehicle speed is second. When the vehicle speed is higher than the vehicle speed, the slipper control is intervened according to the second parameter Pa2.
According to this configuration, it is possible to select an appropriate parameter according to the vehicle speed and perform slip determination.

In the clutch control device 60A of the motorcycle 1, when the vehicle speed is less than the second vehicle speed, the slipper control is not intervened.
According to this configuration, when the vehicle speed is low, the system load can be suppressed by making the slipper control non-intervening.

In the clutch control device 60A of the motorcycle 1, the ECU 60 has opened the throttle of the engine 13 and the ground contact load drop state of the rear wheels 12 has been resolved in a state where the slipper control is intervened. , The intervention of the slipper control is released according to at least one of the above.
According to this configuration, depending on at least one of the fact that the motorcycle 1 has shifted to acceleration and that the decrease in the ground contact load of the rear wheel 12 has been eliminated (in other words, according to the stability of the vehicle condition). ), By canceling the slipper control, the clutch capacity can be quickly restored from the reduced state to the connected state.

<Second embodiment>
Next, a second embodiment of the present invention will be described. The deceleration slipper control and wheel speed correction control of the second embodiment are basically the same as those of the first embodiment, but in the second embodiment, when sudden braking is performed in a region where the bank angle of the vehicle body is large. In addition, the purpose is to realize a reliable intervention of slipper control during deceleration. Specifically, in the second embodiment, even when the vehicle is suddenly braked in the vehicle body bank state, the intervention of the slipper control during deceleration is realized.

In the motorcycle 1, the effective circumference of the tires of the front and rear wheels 2 and 12 (the circumference at the tire contact point) changes due to the influence of various factors. Therefore, even if an attempt is made to detect the wheel speed, a value different from the actual wheel speed may be detected, which makes it difficult to detect the occurrence of a wheel speed difference.
For example, the effective circumference of a tire changes due to the difference in the default circumference due to the difference in tire brand, the difference in circumference due to tire wear, and the difference in circumference due to tire deformation (pneumatic pressure, speed, etc.). It ends up. The change in the effective circumference due to the influence of these tires is corrected by implementing the wheel speed correction control, and the occurrence of the wheel speed difference can be accurately detected.

However, when the vehicle body is banked, the effective circumference of the tire changes due to the change in the contact angle between the road surface and the tire (corresponding to the ground contact angle and the bank angle). In this case, wheel speed correction control becomes difficult. That is, in the region where the bank angle is large, the difference in the change in the effective circumference of the front and rear wheel tires becomes large, and it becomes difficult to accurately detect the occurrence of the wheel speed difference.

With reference to FIGS. 10A to 10C, since the cross-sectional shape (profile) of the tread surface of the tire is different between the front and rear wheels 2 and 12, when the contact angle with the road surface increases, the amount of change in the radius of the tire contact point changes between the front and rear wheels. The amount of change in the effective circumference also differs between the front and rear wheels. The vertical axis of FIG. 10C shows the value (perimeter change rate ratio) obtained by dividing the change rate of the effective circumference of the front wheels (front wheel change rate) by the change rate of the effective circumference of the rear wheels (rear wheel change rate). .. In the second embodiment, the effective circumference of the rear wheels becomes relatively longer as the vehicle body is banked. Therefore, even if both the front and rear wheels are rotating at the same speed, the difference in the change in the effective circumference of the front and rear wheel tires becomes large at the time of banking, and the rotation speed of the rear wheels is apparently low (slow). Therefore, it is easy to determine that the rear wheels are slipping at the time of banking, and slipper control tends to intervene at an early stage.

However, at the time of transition from the banking state to the upright state, on the contrary, the rotation speed of the rear wheels is apparently high (fast), so that the slip of the rear wheels is difficult to be detected, and the intervention of the slipper control may be delayed.
In the second embodiment, in order to realize reliable intervention of slipper control during deceleration even in a region where the bank angle is large, not only the detection of the wheel speed difference but also the deceleration of the front wheel speed (front wheel deceleration (vehicle speed deceleration)). If (corresponding to deceleration)) is above the specified value, the specification allows (starts) the intervention of slipper control during deceleration.

With reference to FIG. 11A, a control intervention pattern at the time of sudden deceleration in an upright state of the vehicle body (bank angle of less than 20 °) will be described.
First, in the case of sudden deceleration in the upright state of the vehicle body, when the vehicle shifts from the accelerated state to the decelerated state, the wheel speed correction control is performed in the region a1 where the load transfer of the vehicle has settled down due to the passage of a predetermined time or the like. After that, by detecting the occurrence of a wheel speed difference, slipper control during deceleration is intervened. At this time, even if the vehicle shifts to the deceleration state, if the vehicle body remains upright (arrow a2 in the figure), the wheel speed correction control accurately detects the occurrence of the wheel speed difference, and the slipper control during deceleration is appropriate. Can intervene in. The frequency of this control intervention pattern is the highest (corresponding to the first embodiment).

Further, at the time of entering a cornering in a race, even if sudden deceleration is started in an upright state of the vehicle body, the vehicle body may be banked to the left or right in the decelerated state (arrows a3 and a4 in the figure). At this time, as described above, the difference in the change in the effective peripheral length of the front and rear wheel tires becomes large, so that the rotation speed of the rear wheels becomes apparently low, and the slipper control during deceleration is intervened earlier. As a result, it is possible to ensure the rear wheel ground contact property at an early stage when the vehicle body is banked in the decelerated state.

Next, with reference to FIG. 11B, a control intervention pattern at the time of sudden deceleration in a vehicle body bank state (bank angle of 20 ° or more) will be described.
First, when the vehicle shifts from the accelerated state to the decelerated state during sudden braking in the vehicle body bank state, wheel speed correction control is performed in the region b1 where the load transfer of the vehicle has settled due to the passage of a predetermined time or the like as described above. do. After that, by detecting the occurrence of a wheel speed difference, slipper control during deceleration is intervened. At this time, even if the vehicle shifts to the deceleration state, if the bank angle remains the same (arrow b2 in the figure) or the bank angle is increased in the same direction (arrow b3 in the figure), as described above. The number of revolutions of the rear wheels is apparently low, and slipper control during deceleration is intervened earlier. As a result, it is possible to ensure the rear wheel ground contact property at an early stage when the vehicle body is banked in the decelerated state.

Further, after starting sudden deceleration in the vehicle body bank state, an operation of reducing the bank angle (returning to the vehicle body upright state) may occur in the deceleration state (arrow b4 in the figure). At this time, since the difference in the change in the effective circumference of the front and rear wheel tires becomes small, the rotation speed of the rear wheels becomes apparently high, and the intervention of the slipper control during deceleration may be delayed. Therefore, in the second embodiment, if the deceleration of the front wheel speed is equal to or higher than a predetermined value, the slipper control during deceleration is specified to intervene. As a result, even when the vehicle body returns from the vehicle body bank state to the vehicle body upright state during sudden deceleration, the rear wheel ground contact property can be ensured at an early stage.

With reference to FIG. 12, even in a bank state where the vehicle body roll angle (bank angle) is equal to or greater than a predetermined value, the wheel speed correction calculation is started when the deceleration of the front wheel speed exceeds a predetermined value (timing tm5). Then, if an increase in the corrected wheel speed ratio (difference) is recognized, slipper control during deceleration is started (timing tm6). After that, when the deceleration of the front wheel speed becomes less than a predetermined value (timing tm7), the wheel speed correction calculation and the slipper control during deceleration are terminated and the clutch is engaged.

By performing the wheel speed correction calculation even in the vehicle body bank state, it is possible to accurately detect the occurrence of a wheel speed difference during deceleration regardless of the tire brand or wear. The implementation conditions of the wheel speed correction calculation at this time will be described with reference to FIG.

First, in the vehicle body bank state, when the throttle grip (TH grip) is closed and the opening degree of the accelerator position sensor (grip APS opening degree) decreases, the throttle opening degree (TH opening degree) starts to decrease immediately after the vehicle body bank state. Shifts from the accelerated state to the decelerated state (timing tm8). At this time, the first timer for waiting for the vehicle body to stabilize starts counting with the closing of the throttle grip as a trigger. The count of the first timer is reset by opening the throttle grip.

In addition to the above first timer, after the throttle grip is closed, the second timer for waiting for vehicle body stabilization starts counting with the trigger that the deceleration of the vehicle speed reaches a predetermined level or more (timing). tm9). The count of the second timer is reset when the deceleration of the vehicle speed becomes less than a predetermined value.

The condition for starting the wheel speed correction calculation in the vehicle body bank state is that all of the following conditions are satisfied.
1. 1. The counts of both timers for waiting for the vehicle body to stabilize have expired. Body bank condition 3. Front wheel speed ≥ predetermined value 4. Front wheel speed deceleration ≧ predetermined value The wheel speed correction calculation is started at the timing tm10 (see FIG. 13) when these conditions are satisfied.

After that, when at least one of the following conditions is satisfied, the wheel speed correction calculation in the vehicle body bank state is completed.
1. 1. Throttle grip opening operation 2. Front wheel speed <predetermined value 3. Front wheel speed deceleration <predetermined value The wheel speed correction calculation ends at the timing tm11 (see FIG. 13) in which at least one of these conditions is satisfied. Even if the vehicle body bank angle changes during the wheel speed correction calculation, the calculation is continued.

In the slipper control at the time of vehicle body bank, it is considered that the bank angle increases (becomes deeper) and the bank angle decreases (becomes shallower) based on the bank angle at the start of wheel speed correction.
When the bank angle becomes deep, the wheel speed ratio tends to increase, so that it becomes easier to enter slipper control, and there is no possibility of non-intervention of control.
On the other hand, when the bank angle becomes shallow, the wheel speed ratio tends to decrease, so that it becomes difficult to enter slipper control, and there is a possibility that control has not been performed. The intervention conditions for slipper control at this time will be described with reference to FIG.

In the example of FIG. 14, when the bank angle changes from a deep state to a shallow state (region in the figure) in the vehicle body bank state and the deceleration state, even if the wheel speed ratio (difference) is less than a predetermined value. If the deceleration of the vehicle speed is more than a predetermined value, slipper control is intervened.

Specifically, the intervention condition for the slipper control is that at least one of the following conditions is satisfied.
1. 1. When front wheel speed ≥ predetermined value, corrected wheel speed ratio ≥ predetermined value 2. If front wheel speed <predetermined value, corrected wheel speed ratio ≥ predetermined value (by gear)
3. 3. Front wheel speed deceleration according to bank angle ≥ threshold (see Fig. 15)
In the example of FIG. 14, in the vehicle body bank state, the corrected wheel speed ratio is less than a predetermined value, but the slipper control is intervened at the timing tm12 when the deceleration of the front wheel speed reaches the predetermined value.

After that, when at least one of the following conditions is satisfied, the intervention of the slipper control is terminated.
1. 1. Throttle grip opening operation 2. Front wheel speed deceleration <predetermined value In the example of FIG. 14, for example, the slipper control intervention is completed at the timing tm13 when the throttle opening operation is performed.

<Control flow>
Next, the processes performed by the ECU 60 at the time of control in the first and second embodiments will be described with reference to FIGS. 16 to 18. This control flow is repeatedly executed in a specified control cycle (1 to 10 msec).

FIG. 16 is a control flow for determining whether or not to shift to wheel speed correction control in the first and second embodiments. In this control flow, whether the wheel speed correction control of the first embodiment or the wheel speed correction control of the second embodiment is performed is divided according to the bank angle of the vehicle body.

That is, first, it is determined whether or not the vehicle body bank angle is equal to or greater than a predetermined value (step S11). If YES in step S11 (the vehicle body bank angle is equal to or greater than a predetermined value), the process proceeds to step S12, and it is determined whether or not the wheel speed correction condition in the vehicle body bank is satisfied. The wheel speed correction conditions in the vehicle body bank are that the vehicle speed is at least a predetermined value, the deceleration is at least a predetermined value, and the grip APS opening degree is at least a predetermined value. If YES (wheel speed correction condition is satisfied) in step S12, the process proceeds to step S13, and wheel speed correction control in the vehicle body bank is performed (second embodiment). The wheel speed correction control itself is the same as that of the first embodiment. If NO (wheel speed correction condition is not satisfied) in step S12, the process is temporarily terminated.

If NO (the vehicle body bank angle is less than a predetermined value) in step S11, the process proceeds to step S14, and it is determined whether or not the wheel speed correction condition while the vehicle body is upright is satisfied. The wheel speed correction conditions while the vehicle is upright are that the vehicle speed is at least specified, the deceleration is at least specified, the grip APS opening is at least specified, and the wheel speed ratio is less than specified. , Are all true. If YES (wheel speed correction condition is satisfied) in step S14, the process proceeds to step S15, and the wheel speed correction condition is performed while the vehicle body is upright (first embodiment). If NO (wheel speed correction condition is not satisfied) in step S14, the process is temporarily terminated.

FIG. 17 is a control flow for determining whether or not slipper control is executed in the first and second embodiments. In this control flow, the difference between the first embodiment and the second embodiment is whether or not deceleration is taken into consideration.

First, it is determined whether or not the wheel speed correction control in the vehicle body bank is being performed (step S21). If YES in step S21 (Wheel speed correction control in the vehicle body bank (second embodiment)), the process proceeds to step S22, and it is determined whether or not the wheel speed ratio is equal to or higher than a predetermined value. If YES (wheel speed ratio is equal to or higher than a predetermined value) in step S22, the process proceeds to step S23, and slipper control in the vehicle body bank is performed. If NO (wheel speed ratio is less than predetermined) in step S22, the process proceeds to step S24, and it is determined whether or not the deceleration is equal to or higher than the predetermined value. If YES (deceleration is equal to or higher than a predetermined value) in step S24, the process proceeds to step S23, and slipper control in the vehicle body bank is performed. That is, even if the wheel speed ratio is less than a predetermined value, if the deceleration is equal to or more than a predetermined value, the slipper control is intervened. If NO (deceleration is less than a predetermined value) in step S24, the process is temporarily terminated.

If NO in step S21 (the wheel speed correction control in the vehicle body bank is not in progress), the process proceeds to step S25, and it is determined whether or not the wheel speed correction control is in progress while the vehicle body is upright. If YES in step S25 (Wheel speed correction control is being performed while the vehicle body is upright (first embodiment)), the process proceeds to step S26, and it is determined whether or not the wheel speed ratio is equal to or higher than a predetermined value. If YES (wheel speed ratio is equal to or higher than a predetermined value) in step S26, the process proceeds to step S27, and slipper control is performed while the vehicle body is upright. If NO in step S25 (the wheel speed correction control is not being performed while the vehicle body is upright) and NO in step S26 (the wheel speed ratio is less than a predetermined value), the process is temporarily terminated.

FIG. 18 is a control flow for determining whether or not to end the slipper control in the first and second embodiments. In this control flow, the end conditions of slipper control differ between the first embodiment and the second embodiment.

First, it is determined whether or not the slipper control end condition is satisfied (step S31). At least one of the conditions for ending the slipper control is that the grip APS opening degree is equal to or greater than a predetermined value and the deceleration is less than a predetermined value. If YES (slipper control end condition is satisfied) in step S31, the process proceeds to step S32 to end the slipper control.

If NO (slipper control end condition is not satisfied) in step S31, the process proceeds to step S33, and it is determined whether or not the slipper is being controlled while the vehicle body is upright. If YES in step S33 (slipper control is being performed while the vehicle body is upright (first embodiment)), the process proceeds to step S34, and it is determined whether or not the wheel speed ratio is less than a predetermined value. If YES (wheel speed ratio is less than a predetermined value) in step S34, the process proceeds to step S32 and the slipper control is terminated.

If NO in step S33 (slipper control is not being performed while the vehicle body is upright (including the second embodiment)), and if NO (wheel speed ratio is equal to or higher than a predetermined value) in step S34, the process is temporarily terminated.
If NO in step S33, the second embodiment includes the second embodiment in which the wheel speed correction control in the vehicle body bank is performed. Therefore, the second embodiment has fewer conditions for ending the slipper control than the first embodiment, and the slipper control is performed. It can be said that it is difficult to finish.

In the clutch control device of the motorcycle 1 in the second embodiment, when the bank angle of the vehicle body is larger than the predetermined value and the deceleration of the vehicle speed is larger than the predetermined value, the front-rear wheel speed difference is less than the predetermined value. However, the slipper control during deceleration is intervened.
That is, in a region where the bank angle of the vehicle body is large, it is difficult to accurately detect the wheel speed difference because the cross-sectional shape of the tread surface of the front and rear wheels is different. The slipper control of the clutch is performed regardless of the wheel speed difference. As a result, slipper control can be appropriately shifted even when the vehicle body is banked, and the rear wheel ground contact property during deceleration of the motorcycle 1 can be ensured.

The present invention is not limited to the above embodiment. For example, in addition to the front / rear wheel speed difference D, for example, the rear wheel can be detected by detecting the operating state of the suspension with a sensor or detecting the vehicle body condition with the gyro sensor 49. A decrease in the ground contact load of 12 may be detected. Instead of using the corrected wheel speed Vrh, the measured rear wheel speed Vr may be used to detect a decrease in the ground contact load of the rear wheel 12 or to make an intervention determination of slipper control.
The above-mentioned saddle-riding vehicle includes all vehicles that the driver rides across the vehicle body, and includes not only motorcycles (including motorized bicycles and scooter-type vehicles) but also three-wheeled vehicles (one front wheel and two rear wheels). , Vehicles with two front wheels and one rear wheel) or vehicles with four wheels and include an electric motor in the prime mover, vehicles that drive the rear wheels (drive wheels) by controlling the prime mover without using a transmission, etc. Is also included.
The configuration in the above embodiment is an example of the present invention, and various changes can be made without departing from the gist of the present invention, such as replacing the constituent elements of the embodiment with well-known constituent elements.

1 Motorcycle (saddle-riding vehicle)
2 Front wheels 12 Rear wheels 13 Engine (motor)
26 Clutch device 50 Clutch actuator 60 ECU (control unit)
60A Clutch controller IP initial point (at a specific point in time)
K1 first specified value (difference)
Vf Front wheel speed Vr Rear wheel speed Vrh Corrected rear wheel speed

Claims (8)

The rear wheels, which are the driving wheels,
The front wheel, which is a driving wheel, and
The prime mover for driving and
A clutch device that disconnects and connects the power transmission between the prime mover and the rear wheel,
A clutch actuator that drives the clutch device to change the clutch capacity,
A control unit for calculating a control target value of the clutch capacity is provided.
The control unit performs slipper control to reduce the clutch capacity when it detects that the rear wheels are in a predetermined ground contact load reduction state when the saddle-riding vehicle decelerates.
The control unit is based on the fact that the rear wheel speed, which is the rotation speed of the rear wheels, becomes lower than the front wheel speed, which is the rotation speed of the front wheels, by more than a predetermined difference. Judges that the ground contact load is in a lowered state.
The control unit is a clutch control device for a saddle-riding vehicle, characterized in that the corrected rear wheel speed obtained by correcting the front wheel speed is used as the rear wheel speed to be compared with the front wheel speed. The saddle-riding vehicle according to claim 1, wherein the corrected wheel speed is obtained by adding the amount of change in the rear wheel speed at the same point to the front wheel speed at the time of wheel speed correction. Clutch control device. The saddle-riding vehicle is in an upright posture, the difference between the front and rear wheel speeds is less than a predetermined value, and the wheel speed correction is started from a specific time point when the throttle of the prime mover is closed. The clutch control device for a saddle-riding vehicle according to claim 1 or 2 . The value obtained by dividing the front wheel speed by the corrected wheel speed is used as the first parameter.
The value obtained by subtracting the corrected wheel speed from the front wheel speed is used as the second parameter.
The clutch control device for a saddle-riding vehicle according to any one of claims 1 to 3 , wherein the slipper control is intervened according to at least one of the first parameter and the second parameter. When the vehicle speed is equal to or higher than the first vehicle speed, the slipper control is intervened according to the first parameter.
The clutch of a saddle-riding vehicle according to claim 4 , wherein when the vehicle speed is lower than the first vehicle speed and equal to or higher than the second vehicle speed, the slipper control is intervened according to the second parameter. Control device. The clutch control device for a saddle-riding vehicle according to claim 5 , wherein the slipper control is non-intervened when the vehicle speed is lower than the second vehicle speed. In the state where the slipper control is intervened, the control unit controls the slipper according to at least one of the fact that the throttle of the prime mover is opened and the state of the ground contact load reduction of the rear wheel is resolved. The clutch control device for a saddle-mounted vehicle according to any one of claims 1 to 6 , wherein the intervention is released. The saddle according to claim 1, wherein when the bank angle of the vehicle body is larger than a predetermined value and the deceleration of the vehicle speed is larger than the predetermined value, the slipper control for reducing the clutch capacity is performed. Clutch control device for riding vehicles.

Images