WO2020066869A1

WO2020066869A1 - Clutch control device

Info

Publication number: WO2020066869A1
Application number: PCT/JP2019/036889
Authority: WO
Inventors: 惇也小野; 達也竜▲崎▼; 森田　豪; 康平松浦
Original assignee: 本田技研工業株式会社
Priority date: 2018-09-26
Filing date: 2019-09-20
Publication date: 2020-04-02
Also published as: DE112019004807T5; JPWO2020066869A1; JP7003288B2; DE112019004807B4

Abstract

This clutch control device is provided with: an engine (13); a transmission (21); a clutch device (26) for connecting/disconnecting power transmission between the engine (13) and the transmission (21); a clutch actuator (50) for changing clutch capacity by driving the clutch device (26); a clutch operator (4b) enabling manual operation of the clutch device (26); and a control unit (60) for calculating a target control value of the clutch capacity in accordance with the operation amount of the clutch operator (4b). The control unit (60), while performing first control for connecting the clutch device (26) by operation of the clutch operator (4b), interveningly performs second control for limiting the clutch capacity in accordance with the engine rotation speed and estimated engine torque, without using the operation of the clutch operator (4b).

Description

Clutch control device

The present invention relates to a clutch control device.
Priority is claimed on Japanese Patent Application No. 2018-180744, filed Sep. 26, 2018, the content of which is incorporated herein by reference.

鞍 A saddle-ride type vehicle including an automatic clutch system in which a clutch provided between an engine and a transmission is driven by an actuator is disclosed. This technology prevents a stall (meaning engine stop or engine stall) and a reduced ride feeling by devising half-clutch control when the clutch is engaged (for example, see Patent Document 1). .

Japanese Patent Application Laid-Open No. 2014-035065

By the way, the above-mentioned conventional technology is not based on the clutch-by-wire system, and there is no concept of respecting the rider's operation intention. That is, there is a problem that even if the half-clutch control is performed to avoid the engine stall, if the control frequently intervenes against the intention of the rider, the rider may feel uncomfortable.

An object of the present invention is to provide a clutch control device that also functions as a clutch-by-wire system capable of connecting and disconnecting a clutch via a clutch actuator, while suppressing engine stall avoidance control and suppressing a rider's discomfort.

As means for solving the above-mentioned problems, aspects of the present invention have the following configurations.
(1) A clutch control device according to an aspect of the present invention includes an engine, a transmission, a clutch device for connecting and disconnecting power transmission between the engine and the transmission, and a clutch capacity that is driven by driving the clutch device. A clutch actuator to be changed, a clutch operator for manually operating the clutch device, and a control unit for calculating a control target value of the clutch capacity according to an operation amount of the clutch operator. The unit is configured to perform the first control for connecting the clutch device by operating the clutch operator, and perform the clutch operation regardless of the operation of the clutch operator in accordance with an engine speed and an estimated engine torque. Intervening a second control to limit the capacity.

(2) In the clutch control device according to (1), the control unit obtains a limited clutch oil pressure at which the engine speed becomes an engine stall determination threshold after a predetermined time has elapsed, and compares the limited clutch oil pressure with a current target oil pressure. Then, the second control may be intervened.

(3) In the clutch control device according to the above (2), the specified time may be a time required for disengaging the clutch.

(4) In the clutch control device according to (3), the control unit may intervene in the second control when the limited clutch oil pressure is equal to or less than a target oil pressure.

(5) In the clutch control device according to the above (3) or (4), the limit value of the clutch capacity set in the second control is the specified time, the clutch connection rotation speed, and the engine stall determination threshold. And the engine estimated torque.

(6) In the clutch control device described in (3) or (4), the limit value of the clutch capacity set in the second control is based on a limit value map that changes according to the engine speed. It may be calculated.

(7) In the clutch control device according to the above (6), the limited value of the clutch capacity set in the second control is the specified time, a difference between a clutch connection rotation speed and the engine stall determination threshold value. The first limit value calculated based on the engine estimated torque may be compared with a second limit value calculated based on the limit value map.

According to the clutch control device described in the above (1) of the present invention, in the clutch-by-wire system, the engine speed and the throttle opening are always set during the first control for connecting the clutch device by operating the clutch operator. From this, after the specified time has elapsed, a limit clutch oil pressure (limit clutch capacity) serving as an engine stall determination threshold is obtained, and when it is determined that the target oil pressure exceeds the limit clutch oil pressure (there is a possibility of engine stall), the clutch operator Intervenes a second control that does not depend on the operation of. Accordingly, even when the engine is likely to stall when the rider's operation is prioritized, it is possible to intervene the second control before the engine stalls to limit the clutch capacity (set a half-clutch state). . For this reason, an unintended engine stall at the time of the clutch connection operation can be avoided.
Further, since the above determination is always made and the possibility of engine stall is determined, accurate engine stall prediction based on the actual engine speed and the throttle opening can be made, and the intervention determination of the second control (engine stall avoidance control) is made. The accuracy of is increased. Therefore, as compared with a case where the engine stall avoidance control is intervened early with a margin, it is possible to reduce the intervention frequency of the engine stall avoidance control and suppress the rider from feeling uncomfortable.

According to the clutch control device described in the above (2) of the present invention, at the time of the first control by the operation of the clutch operation member, the engine stall determination threshold value after the lapse of a specified time is always determined from the engine speed and the throttle opening. Is determined, and if it is determined that the target hydraulic pressure exceeds the limited clutch hydraulic pressure (there is a possibility of engine stall), the second control that does not depend on the operation of the clutch operator is performed. Intervene. Accordingly, even if the engine stalls when the rider's operation is prioritized, the clutch capacity can be limited by intervening the second control before the engine stalls. For this reason, an unintended engine stall at the time of the clutch connection operation can be avoided.

According to the clutch control device described in the above (3) of the present invention, the time required for disengaging the clutch is counted from the time when the engine speed decreases when the clutch is engaged, and the specified engine speed is determined in the future (after the specified time). A limit clutch oil pressure that is a number (lower limit value) is obtained, and it is determined whether or not this limit clutch oil pressure becomes equal to or lower than the target oil pressure. If it is determined that the limited clutch hydraulic pressure becomes equal to or lower than the target hydraulic pressure, the clutch capacity is limited before the engine stalls by switching to the second control independent of the operation of the clutch lever. By setting the lower limit of the future engine speed and limiting the clutch capacity in this way, unintended engine stall can be avoided. “Time required for clutch disconnection” means a time lag from when the control unit issues a clutch disconnection instruction to when clutch disconnection is actually started. In other words, when connecting the clutch, when the clutch connection speed is too high and engine stall is likely to occur, an instruction to disconnect the clutch is issued immediately so that the time required for clutch disengagement can be set in time to avoid engine stall. Is considered.

According to the clutch control device described in the above (4) of the present invention, when the limited clutch oil pressure becomes equal to or less than the target oil pressure, by switching to the second control independent of the operation of the clutch lever, the engine is controlled before the engine stalls. Limit clutch capacity. By setting the lower limit of the future engine speed and limiting the clutch capacity in this way, unintended engine stall can be avoided.

According to the clutch control device described in (5) of the present invention, the control unit sets the limit value of the clutch capacity separated from the clutch operation based on the difference between the specified time and the engine speed and the estimated engine torque. . As a result, the clutch capacity can be limited in accordance with the prediction of the future engine speed, and engine stall can be avoided.

According to the clutch control device described in (6) of the present invention, the control unit sets the limit value of the clutch capacity separated from the clutch operation based on the limit value map that changes according to the engine speed. As a result, the clutch capacity can be limited in accordance with the prediction of the future engine speed, and engine stall can be avoided.

According to the clutch control device described in (7) of the present invention, the control unit includes: a first limit value calculated from a change rate based on a difference between the specified time and the engine speed and the engine estimated torque; Is compared with the second limit value calculated from the limit value map that changes in accordance with, for example, a relatively low value is set as the clutch capacity limit value. This makes it possible to set a suitable limit value according to the engine speed and the like. Then, the clutch capacity can be limited according to the prediction of the future engine speed, and engine stall can be avoided.

FIG. 2 is a left side view of the motorcycle according to the embodiment of the present invention. FIG. 2 is a sectional view of a transmission and a change mechanism of the motorcycle. It is a schematic explanatory view of a clutch operation system including a clutch actuator. It is a block diagram of a transmission system. 4 is a graph showing a change in supply hydraulic pressure of a clutch actuator. 6 is a graph showing a correlation between a clutch lever operation amount, a sensor output voltage, and a clutch capacity according to the embodiment of the present invention. FIG. 4 is an explanatory diagram illustrating a transition of a clutch control mode according to the embodiment of the present invention. 5 is a graph showing a time change of an engine speed at the time of clutch engagement by lever operation in the clutch control device according to the embodiment of the present invention. It is explanatory drawing which shows the outline of a clutch upstream part and a clutch downstream part. 4 is a map showing a change in clutch limit hydraulic pressure with respect to an engine speed. 5 is a time chart showing changes in control parameters in the clutch control device according to the embodiment of the present invention. It is a principal part enlarged view of FIG.

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

<Whole vehicle>
As shown in FIG. 1, the present embodiment is applied to a motorcycle 1 as an example of a saddle type vehicle. A front wheel 2 of the motorcycle 1 is supported by lower ends of a pair of left and right front forks 3. The upper portions of the left and right front forks 3 are supported by a head pipe 6 at the front end of a vehicle body frame 5 via a steering stem 4. A bar-type steering handle 4 a 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 a center of the head pipe 6 in a vehicle width direction (lateral direction), a left and right pivot frame 8 extending below a rear end of the main tube 7, And a seat frame 9 connected to the rear of the tube 7 and the left and right pivot frames 8. The front ends of the swing arms 11 are pivotally supported by the left and right pivot frames 8 in a swingable manner. At the rear end of the swing arm 11, a rear wheel 12 of the motorcycle 1 is supported.

燃料 A fuel tank 18 is supported above the left and right main tubes 7. Above the seat frame 9 behind the fuel tank 18, a front seat 19 and a rear seat cover 19a are supported side by side. 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 a 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. The engine 13 is, for example, a multi-cylinder engine in which the rotation axis of a crankshaft 14 extends along the left-right direction (vehicle width direction). The engine 13 has a cylinder 16 erected above a front part of the crankcase 15. The rear part 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 extending over both

shafts

22, 23. The counter shaft 23 constitutes the transmission 21 and thus the output shaft of the power unit PU. The end of the counter shaft 23 projects to the rear left side of the crankcase 15 and is connected to the rear wheel 12 via the above-mentioned chain type transmission mechanism.

The transmission gear group 24 has gears for the number of gears supported by the

shafts

22 and 23, respectively. The transmission 21 is of a constant mesh type in which the corresponding gear pairs of the transmission gear group 24 are always meshed between the two

shafts

22 and 23. The plurality of gears supported by both

shafts

22 and 23 are classified into a free gear rotatable with respect to the corresponding shaft, and a slide gear (shifter) spline-fitted to the corresponding shaft. One of the free gear and the slide gear is provided with an axially convex dog, and the other is provided with an axially concave slot for engaging the dog. That is, the transmission 21 is a so-called dog mission.

メイン The main shaft 22 and the counter shaft 23 of the transmission 21 are arranged in front of and behind the crankshaft 14. At the right end of the main shaft 22, a clutch device 26 operated by a clutch actuator 50 (see FIG. 3) is coaxially arranged. The clutch device 26 is, for example, a wet multi-plate clutch, and is a so-called normally open clutch. That is, the clutch device 26 is brought into 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 is not supplied from the clutch actuator 50.

The rotational power of the crankshaft 14 is transmitted to the main shaft 22 via the clutch device 26, and transmitted from the main shaft 22 to the counter shaft 23 via an arbitrary gear pair of the transmission gear group 24. A drive sprocket 27 of the above-described chain type transmission mechanism is attached to a left end portion of the countershaft 23 protruding to the rear left side of the crankcase 15.

チェンジ Above the rear of the transmission 21, a change mechanism 25 that switches a gear pair of the transmission gear group 24 is accommodated. The change mechanism 25 operates a plurality of shift forks 36 a according to a pattern of a lead groove formed on the outer periphery of the shift gear group 24 by rotating a hollow cylindrical shift drum 36 parallel to the

shafts

22 and 23. The gear pair used for power transmission between the two

shafts

22 and 23 is switched.

The change mechanism 25 has a shift spindle 31 parallel to the shift drum 36. When the shift spindle 31 rotates, the shift arm 31a fixed to the shift spindle 31 rotates the shift drum 36, and moves the shift fork 36a in the axial direction according to the pattern of the lead groove, so that the power in the transmission gear group 24 is changed. The transmissible gear pair is switched (that is, the gear position is switched).

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

As shown in FIG. 1, the front end of the shift pedal 32 is supported at the lower part of the crankcase 15 via a shaft extending in the left-right direction so as to be vertically swingable. The rear end of the shift pedal 32 is provided with a pedal portion for hanging the driver's toe placed on the step 32a, and the lower end of a link rod 34 is connected to the front and rear middle portion of the shift pedal 32.

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

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

<Transmission system>
As shown in FIG. 4, the transmission system includes a clutch actuator 50, an ECU 60 (Electronic Control Unit, control unit), and various sensors 41 to 45.
The ECU 60 detects information from a gear position sensor 41 that detects a gear position based on 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 speed sensor 45, and the like, the operation of the clutch actuator 50 is controlled, and the operation of the ignition device 46 and the fuel injection device 47 are controlled.
The ECU 60 also receives detection information from

hydraulic sensors

57 and 58, which will be described later, and a shift operation detection switch (shift neutral switch) 48.
The ECU 60 includes a hydraulic control unit (clutch control unit) 61, and its function will be described later. Reference numeral 60A in the figure indicates a clutch control device of the present embodiment.

Referring also to FIG. 3, the clutch actuator 50 is controlled to be operated by the ECU 60, so that the hydraulic pressure for connecting and disconnecting the clutch device 26 can be controlled. The clutch actuator 50 includes an electric motor 52 (hereinafter simply referred to as a motor 52) as a driving source, and a master cylinder 51 driven by the motor 52. The clutch actuator 50 and the hydraulic circuit device 53 provided between the master cylinder 51 and the hydraulic supply / discharge port 50p constitute an integral clutch control unit 50A.
The ECU 60 calculates a target value (a target hydraulic pressure) of the hydraulic pressure supplied to the slave cylinder 28 for connecting and disconnecting the clutch device 26 based on a preset calculation program. 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 allows the piston 51b in the cylinder body 51a to stroke by driving the motor 52 so that the hydraulic oil in the cylinder body 51a can be supplied to and discharged from the slave cylinder 28. In the figure, reference numeral 55 denotes a conversion mechanism as a ball screw mechanism, reference numeral 54 denotes a transmission mechanism extending over the motor 52 and the conversion mechanism 55, and reference numeral 51e denotes a reservoir connected to the master cylinder 51.

The hydraulic circuit device 53 has a valve mechanism (solenoid valve 56) for opening or closing an intermediate portion of a main oil passage (hydraulic oil supply / discharge oil passage) 53m extending from the master cylinder 51 to the clutch device 26 side (slave cylinder 28 side). doing. The main oil passage 53m of the hydraulic circuit device 53 is divided into an upstream oil passage 53a closer to the master cylinder 51 than the solenoid valve 56, and a downstream oil passage 53b closer to the slave cylinder 28 than the solenoid valve 56. . The hydraulic circuit device 53 further includes a bypass oil passage 53c that bypasses the solenoid valve 56 and connects 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. An upstream oil pressure sensor 57 that detects the oil pressure of the upstream oil passage 53a is provided upstream of the solenoid valve 56. Downstream of the solenoid valve 56, a downstream oil pressure sensor 58 for detecting the oil pressure of the downstream oil passage 53b is provided.

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

スレーブ As shown in FIG. 2, the slave cylinder 28 is coaxially arranged to the left of the main shaft 22. When hydraulic pressure is supplied from the clutch actuator 50, the slave cylinder 28 presses the push rod 28a penetrating through the main shaft 22 to the right. The slave cylinder 28 presses the push rod 28a rightward, thereby operating the clutch device 26 to the connected state via the push rod 28a. When the supply of the hydraulic pressure is stopped, the slave cylinder 28 releases the pressing of the push rod 28a, and returns the clutch device 26 to the disconnected state.

するには In order to maintain the clutch device 26 in the connected state, it is necessary to continue the hydraulic pressure supply, but the power is consumed accordingly. Therefore, as shown in FIG. 3, a solenoid valve 56 is provided in the hydraulic circuit device 53 of the clutch control unit 50A, and the solenoid valve 56 is closed after hydraulic pressure is supplied to the clutch device 26 side. Thereby, the oil pressure supplied to the clutch device 26 side is maintained, and the oil pressure is compensated for by the pressure decrease (recharge is performed by the leak amount), thereby reducing energy consumption.

<Clutch control>
Next, the operation of the clutch control system will be described with reference to the graph of FIG. In the graph of FIG. 5, the vertical axis indicates the supply oil pressure detected by the downstream oil pressure sensor 58, and the horizontal axis indicates the elapsed time.
When the motorcycle 1 stops (idle), the power supply to both the motor 52 and the solenoid valve 56 controlled by the ECU (control unit) 60 is cut off. That is, the motor 52 is in a stopped state, and the solenoid valve 56 is in an open state. At this time, the slave cylinder 28 side (downstream side) is in a low pressure state lower than the touch point oil pressure TP, and the clutch device 26 is in a non-engaged state (disconnected state, released state). This state corresponds to the area A in FIG.

When the number of revolutions of the engine 13 is increased when the motorcycle 1 starts moving, power is supplied only to the motor 52, and hydraulic pressure is supplied from the master cylinder 51 to the slave cylinder 28 via the solenoid valve 56 in a valve open state. When the hydraulic pressure on the slave cylinder 28 side (downstream side) rises above the touch point hydraulic pressure TP, the engagement of the clutch device 26 is started, and the clutch device 26 enters a half-clutch state where some power can be transmitted. Thus, the motorcycle 1 can start smoothly. This state corresponds to region B in FIG.
Eventually, when the difference between the input rotation and the output rotation of the clutch device 26 is reduced and the hydraulic pressure on the slave cylinder 28 side (downstream side) reaches the lower limit holding hydraulic pressure LP, the engagement of the clutch device 26 shifts to the locked state, and the engine 13 Are transmitted to the transmission 21. This state corresponds to a region C in FIG. The areas A to C are set as the start areas.

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

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

Here, depending on the speed change operation, the speed change may be performed immediately after the hydraulic pressure is filled in the clutch device 26. In this case, before the solenoid valve 56 is closed and the upstream side is set to the low pressure state, the motor 52 is driven to rotate in the reverse direction with the solenoid valve 56 kept open to reduce the pressure of the master cylinder 51 and to connect the reservoir 51e. Then, the hydraulic pressure on the clutch device 26 side is relieved to the master cylinder 51 side. At this time, the drive of the clutch actuator 50 is feedback-controlled based on the detected oil pressure of the upstream oil pressure sensor 57.

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

On the other hand, as shown in a region E of FIG. 5, the hydraulic pressure on the downstream side may increase due to an increase in temperature or the like. A small hydraulic fluctuation on the downstream side can be absorbed by an accumulator (not shown), and the power consumption is not increased by operating the motor 52 and the solenoid valve 56 every time the hydraulic pressure fluctuates.
When the downstream oil pressure rises to the upper limit holding oil pressure HP as shown in a region E of FIG. 5, the solenoid valve 56 is gradually opened by, for example, decreasing the power supply to the solenoid valve 56, and the downstream oil pressure is increased. Relief pressure to the upstream side.

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

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

On the other hand, if the transmission 21 is kept in the in-gear state when the motorcycle 1 is stopped, a standby state is established in which the standby hydraulic pressure WP is applied to the slave cylinder 28 side.
The standby hydraulic pressure WP is slightly lower than the touch point hydraulic pressure TP at which the connection of the clutch device 26 is started, and is a hydraulic pressure at which the clutch device 26 is not connected (the hydraulic pressure applied in the regions A and H in FIG. 5). The provision of the standby hydraulic pressure WP enables the clutch device 26 to be invalidly packed (cancellation of backlash and operation reaction force of each part, application of a preload to the hydraulic path, and the like), and operation responsiveness when the clutch device 26 is connected is improved.

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

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

The standby hydraulic pressure WP is set to the first set value P1 (see FIG. 5) which is the standard standby hydraulic pressure during normal times (in a non-detection state in which the shift operation of the shift pedal 32 is not detected). As a result, the clutch device 26 enters a standby state in which the clutch device 26 has been invalidated, and the responsiveness at the time of clutch engagement is enhanced. That is, when the driver increases the rotational speed of the engine 13 by increasing the throttle opening, the engagement of the clutch device 26 is immediately started by the supply of the hydraulic pressure to the slave cylinder 28, so that the motorcycle 1 can be quickly started and accelerated. It becomes possible.

The motorcycle 1 includes a shift operation detection switch 48 separately from the shift load sensor 42 to detect a driver's shift operation on the shift pedal 32. The shift operation detection switch 48 is disposed, for example, opposite to the distal end of the shift arm 31a, and detects a slight rotation of the shift spindle 31 due to a shift operation of the shift pedal 32 with high sensitivity.
When the shift operation detection switch 48 detects a shift operation from first gear to neutral in the in-gear stopped state, the hydraulic control unit 61 sets the standby hydraulic pressure WP to a value higher than the first set value P1 before performing the shift operation. Control is also performed to set a second set value P2 (low-pressure standby oil pressure, see FIG. 5) which is also low.

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

<Clutch control mode>
As shown in FIG. 7, the clutch control device 60A of the present embodiment has three types of clutch control modes. The clutch control mode includes a clutch control mode changeover switch 59 (FIG. 4) among three modes: an automatic mode M1 for performing automatic control, a manual mode M2 for performing manual operation, and a manual intervention mode M3 for performing temporary manual operation. The transition is made appropriately in accordance with the operation of the clutch lever (see FIG. 1) and the clutch lever (clutch operator) 4b (see FIG. 1). An object including the manual mode M2 and the manual intervention mode M3 is referred to as a manual system M2A.

The automatic mode M1 is a mode in which the clutch device 26 is controlled by calculating a clutch capacity suitable for a running state by automatic start / shift control. The manual mode M2 is a mode in which the clutch capacity is calculated in accordance with a clutch operation instruction from the occupant to control the clutch device 26. The manual intervention mode M3 is a temporary manual operation mode in which a clutch operation instruction from an occupant is received during the automatic mode M1, and a clutch capacity is calculated from the clutch operation instruction to control the clutch device 26. It should be noted that the setting is made such that when the occupant stops operating the clutch lever 4b (completely releases) during the manual intervention mode M3, the mode returns to the automatic mode M1.

The clutch control device 60 </ b> A of the present embodiment generates an oil pressure for clutch control by driving an oil pump (not shown) with the rotational driving force of the engine 13. For this reason, when starting the system, the clutch control device 60A starts the control from the clutch off state (disengaged state) in the auto mode M1. Further, the clutch control device 60A is set to return to the clutch off in the automatic mode M1 because the clutch operation is not required when the engine 13 is stopped.

In the auto mode M1, the clutch control is performed automatically, and the motorcycle 1 can run without operating the lever. In the auto mode M1, the clutch capacity is controlled based on the throttle opening, engine speed, vehicle speed, and shift sensor output. Thus, the motorcycle 1 can be started without stalling (engine stop or engine stall) only by throttle operation, and can be shifted only by shift operation. However, at an extremely low speed equivalent to idling, the clutch device 26 may be automatically disconnected. In the automatic mode M1, the manual intervention mode M3 is established by gripping 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 automatic mode M1 and the manual mode M2 can be switched by operating the clutch control mode changeover switch 59 (see FIG. 4) while the vehicle is stopped. Note that the clutch control device 60A may include an indicator indicating that the lever operation is valid 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 control is basically performed manually, and the clutch oil pressure can be controlled according to the operating angle of the clutch lever 4b. Thus, the connection and disconnection of the clutch device 26 can be controlled with the intention of the occupant, and the clutch device 26 can be connected and run even at an extremely low speed equivalent to idling. However, the engine may stall depending on the operation of the lever, and it is impossible to automatically start only by operating the throttle. Even in the manual mode M2, the clutch control automatically intervenes during the shift operation.

In the auto mode M1, the clutch device 50 is automatically connected and disconnected by the clutch actuator 50. However, the manual operation is temporarily performed in the automatic control of the clutch device 26 by performing the manual clutch operation on the clutch lever 4b. Is possible (manual intervention mode M3).

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

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

併せ Referring also to FIG. 4, the clutch lever 4b is integrally provided with a clutch lever operation amount sensor 4c for detecting an operation amount (rotation angle) of the clutch lever 4b. The clutch lever operation amount sensor 4c converts the operation amount of the clutch lever 4b into an electric signal and outputs the electric signal. When the operation of the clutch lever 4b is valid (manual system M2A), the ECU 60 drives the clutch actuator 50 based on the output of the clutch lever operation amount sensor 4c. Note that the clutch lever 4b and the clutch lever operation amount sensor 4c may be integrated with each other or separate from each other.

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

Referring also to FIG. 6, the clutch lever 4b is released without being squeezed by the occupant and rotated to the clutch connection side, and the clutch lever 4b is moved to the grip side (clutch disengagement side) by the occupant's grasp. It is rotatable between an abutting state in which it rotates and hits the grip. When the clutch lever 4b is released from the gripping operation by the occupant, the clutch lever 4b is urged to return to the released state, which is the initial position.

For example, the clutch lever operation amount sensor 4c sets the output voltage to zero in a state where the clutch lever 4b is completely squeezed (abutting state), and from this state, the release operation of the clutch lever 4b (operation to the clutch connection side) is started. It is configured to increase the output voltage in response to what is done. In the present embodiment, of the output voltage of the clutch lever operation amount sensor 4c, a gap is secured between the lever play existing at the start of gripping of the clutch lever 4b and the finger between the gripped lever and the grip. The range excluding the abutment margin is set as the range of the effective voltage (the range of effective operation of the clutch lever 4b).

Specifically, an effective voltage is applied between the operation amount S1 in which the clutch lever 4b is released from the abutting state of the clutch lever 4b by the abutment margin and the operation amount S2 in which the clutch lever 4b is released until the lever play starts. Are set to correspond to the range of the lower limit value E1 to the upper limit value E2. The range from the lower limit value E1 to the upper limit value E2 is proportional to the range of the calculated value of the manually operated clutch capacity from zero to MAX. As a result, the effects of mechanical backlash and sensor variations can be reduced, and the reliability of the clutch drive amount required by manual operation can be increased. The upper limit value E2 of the effective voltage may be set when the operation amount S1 of the clutch lever 4b is set, and the lower limit value E1 may be set when the operation amount S2 is set.

<Stall avoidance control>
Next, engine stall avoidance control of the motorcycle 1 will be described.
The clutch control device 60A (clutch-by-wire system) controls the clutch capacity by the operation amount (operation angle) of the clutch lever 4b when disconnecting and connecting the clutch device 26 in the manual system M2A (hereinafter referred to as a manual system mode). . The basis of the clutch-by-wire system is that the clutch device 26 is interlocked in accordance with the operation amount of the clutch lever 4b (hereinafter, sometimes abbreviated as lever operation amount). Normally, the ECU 60 calculates the target value of the clutch capacity (the target value of the clutch control oil pressure (the target oil pressure)) according to the lever operation amount. Specifically, the target oil pressure according to the lever operation amount is retrieved from a map (not shown) showing a correlation (substantially proportional relationship) between the operation angle of the clutch lever 4b and the target oil pressure. Hereinafter, the target oil pressure according to the lever operation amount is referred to as an operation oil pressure.

When connecting the clutch device 26 in the manual system mode, the clutch control device 60A performs the first control for connecting the clutch device 26 by operating the clutch lever 4b, but also performs the first control in accordance with the engine speed and the engine estimated torque. The following second control is interposed. In the second control, the clutch capacity is limited according to a preset procedure (lower the hydraulic pressure target value) regardless of the operation angle of the clutch lever 4b.

制限 The limit value of the clutch capacity is determined based on the surplus rotational energy for the engine stall obtained from the engine speed and the estimated engine torque. That is, if the engine speed and the engine estimated torque that do not cause the engine to stall can be ensured even if the engine speed drops when the clutch is engaged, the clutch capacity limit value is not set (the clutch capacity is not limited). On the other hand, if it is not possible to secure the engine speed and the engine estimated torque that do not cause the engine to stall when the clutch is engaged (when there is a possibility of engine stall), a clutch capacity limit value is set (the clutch capacity is limited) and the lever operation is performed. The target oil pressure is set lower than the corresponding operation oil pressure.

Accordingly, when the clutch device 26 is connected in the manual mode, half clutch control is interposed regardless of the operation angle of the clutch lever 4b. The half clutch control reduces the clutch capacity of the clutch device 26. The slip (clutch slip) occurs in the clutch device 26 due to the decrease in the clutch capacity. Due to the clutch slip, the clutch device 26 generates a clutch differential rotation.

Referring to FIG. 9, the clutch differential rotation refers to the rotation speed on the downstream side (drive wheel side) of the clutch device 26 with respect to the rotation speed on the upstream side (engine side) of the clutch device 26 (the rotation speed of the crankshaft). (The rotation speed of the main shaft). Due to the occurrence of the clutch differential rotation, the engine speed is secured to such an extent that the engine does not stall.

Referring to FIG. 8, the ECU 60 always provides a limited clutch oil pressure (limited clutch) at which the engine speed reaches a predetermined engine stall determination threshold value _Neidle + α before the predetermined specified time Time _dec elapses from the start of clutch connection. Capacity). The limited clutch oil pressure is an oil pressure at which the clutch capacity reaches a limit value Tclutch described later. This limit clutch oil pressure is compared with the current target oil pressure, and when it is determined that the limit clutch oil pressure is equal to or less than the current target oil pressure (in other words, when it is determined that there is a possibility of engine stall in the clutch connection at the current target oil pressure). ), Intervening the second control (stall avoidance control) to avoid the engine stall. It can be said that the second control is against the rider's intention to operate the clutch because the control is to operate the clutch device 26 separately from the operation angle of the clutch lever 4b.

In order to ensure the engine stall avoidance, it is conceivable to set the engine stall determination threshold to a higher value. That is, it is conceivable that the engine stall avoidance control is intervened early with a margin. However, in this case, the frequency of intervention of the engine stall avoidance control contrary to the intention of the rider increases, and the rider may feel uncomfortable.

In the present embodiment, the following control is performed in order to avoid the engine stall while respecting the intention of the rider as much as possible.
The ECU 60 predicts the limited clutch oil pressure at which the engine speed becomes equal to the engine stall determination threshold value _Neidle + α after the lapse of the specified time Time _dec from the start of the clutch connection (every calculation cycle of the ECU 60 (for example, every 5 msec)). The oil pressure is compared with the current target oil pressure to determine the intervention of engine stall avoidance control. The specified time (Time _dec ) is a time required for clutch disengagement (a predetermined value of about 100 msec), and corresponds to a time lag from when the ECU 60 issues a clutch disengagement instruction to when clutch disengagement is actually started.

When the engine speed drops when the clutch is engaged, a limited clutch oil pressure at which the engine speed will become the engine stall determination threshold value _Neidle + α in the future (after the next specified time Time _dec ) is predicted, and this limited clutch oil pressure becomes the current target oil pressure. The clutch capacity (target oil pressure) is limited as follows. The engine speed at the time when the engine speed starts to decrease at the start of the clutch engagement is _defined as the clutch _engagement speed _Neidle + α + β.

Next, a method of calculating the limit value Tclutch of the clutch capacity (target oil pressure) will be described.
First, Table 1 is a list of parameters used in this description.

In the present embodiment, the clutch capacity limit value Tclutch is set such that a decrease in the engine speed due to the clutch connection becomes the following condition with respect to the current engine speed.
First, referring to the graph of FIG. 8, the time required for the engine speed Ne to decrease from “Ne _idle + α + β” (the speed at the time of clutch _engagement ) to “Ne _idle + α” (the engine stall determination threshold) in the diagram is In the figure, it is _{assumed that} “Time _dec ” (specified time, substantially 100 msec) or more is secured.

The equations of motion on the upstream side of the clutch when the slippage occurs in the clutch device 26 are shown in the following equations (1) to (3).

The range of the clutch capacity limit value T _clutch is calculated from Equations 1 to 3 above (Equation 4 below). In the equation, “β” corresponds to a difference between the clutch _engagement rotational speed Ne _idle + α + β and the engine stall determination threshold Ne _idle + α. In Expression 4, the difference β is a negative value because only the side on which the engine speed decreases is considered.

From the above equation (4), the range of the clutch capacity limit value T _clutch is represented by the following equation (5).

A clutch capacity limit value T _clutch obtained in the range of Expression 5 is set as a first limit value A. It can be said that the first limit value A is calculated based on the specified time Time _dec and the difference β between the clutch _engagement rotational speed Ne _idle + α + β and the engine stall determination threshold value Ne _idle + α.

On the other hand, in order to improve the engine toughness (difficulty of engine stall), it is also possible to set a limit value of the clutch capacity according to the engine speed without depending on the engine torque. This limit value is obtained from the map in FIG. 10 in which the vertical axis represents the limited hydraulic pressure and the horizontal axis represents the engine speed. The clutch capacity limit value T _clutch obtained from this map is defined as a second limit value B.

Finally, the limit value T _clutch of the clutch capacity (target oil pressure) is set as shown in Table 2 below.

As shown in Table 2, when the engine speed is in the range of _Neidle or less and _Neidle + α or less, the clutch capacity limit value T _clutch is set to such an extent that the drag torque of the clutch device 26 is allowed.
When the engine speed is in the range of _Neidle + α + β or more, as the clutch capacity limit value T _clutch , a lower value is selected from the first limit value A and the second limit value B.

With reference to the graphs of FIGS. 11 and 12, a description will be given of the time change of the clutch control parameter.
The graphs of FIGS. 11 and 12 show the time of each parameter from the state where the clutch lever 4b is squeezed and the clutch device 26 is disconnected to the time when the clutch lever 4b is released and the clutch device 26 is connected. The change is shown.

スロットル As shown on the left side of the region J in FIG. 11, before the clutch device 26 is connected in the manual system mode, the throttle opening is opened by th1, and the estimated engine torque is maintained at tq1. At this time, the engine speed is increased to such an extent that the engine does not stall when the clutch is engaged. At this time, the clutch is disengaged, and the vehicle speed is maintained at 0. That is, the example of FIG. 11 shows a state in which the motorcycle 1 starts moving.

(4) As the clutch connection operation, when the clutch lever 4b is rotated to the release side to reduce the operation angle (lever angle), the target hydraulic pressure rises soon, and the slave hydraulic pressure rises soon (region K in FIG. 12). When the slave oil pressure rises and exceeds the touch point oil pressure TP, the engine speed decreases and the counter shaft torque increases, thereby increasing the vehicle speed (starting the motorcycle 1). The timing t1 at which the slave hydraulic pressure reaches the touch point hydraulic pressure TP corresponds to the timing of starting the clutch connection (see FIG. 8). After the timing t1, the clutch device 26 enters the half-clutch state.

The timing t2 at which the engine speed decreases until the engine speed reaches the clutch-engaged speed _Neidle + α + β after the clutch connection is started corresponds to the timing of the engine stall avoidance control intervention. An area L after the timing t2 is an area where the first control according to the lever operation amount shifts to the second control (engine stall avoidance control) not depending on the lever operation amount. After the timing t2, the engine pressure is limited (reduced) with respect to the operation oil pressure by intervening the engine stall avoidance control that does not depend on the lever operation amount even in the manual system mode, and the half-clutch state is changed against the lever operation amount. maintain.

By generating the half clutch state, clutch differential rotation occurs, and the countershaft torque decreases. The motorcycle continues running while gradually increasing the vehicle speed. Soon, as shown in FIG. 11, when the vehicle speed rises to the prescribed connection determination threshold value V1, the ECU 60 determines that engine stall does not occur even when the clutch device 26 is fully connected, and returns to the first control to return to the first control. The process returns to the clutch control according to the operation amount. This makes it possible to linearly connect the clutch device 26 in accordance with the lever operation amount.

Referring to FIG. 8 and Table 1, the rider grips the clutch lever 4b to release the clutch lever 4b (until the engine speed reaches the clutch _engagement speed Ne _idle + α + β to the engine stall threshold _Neidle + α). Is the engine rotation speed reduction securing time Time _dec . For example, the engine rotation speed decrease securing time Time _dec is determined from the decrease determination state in which the slope (absolute value) of the engine rotation speed Ne is equal to or more than the decrease determination value, and the slope (absolute value) of the engine rotation speed Ne being reduced in reduction determination value. It corresponds to the time until the reduced elimination state becomes as follows. The engine rotation speed reduction ensuring time Time _dec corresponds to the above specified time Time _dec .

The ECU 60 always calculates the limited clutch oil pressure during the lever operation when the clutch is engaged. The limited clutch oil pressure is a clutch oil pressure that is predicted to become the engine stall determination threshold after a lapse of a specified time from the engine speed and the throttle opening. The difference β between the clutch _engagement speed Ne _idle + α + β and the engine stall determination threshold value Ne _idle + α is a predetermined value, and is a marginal engine speed until the engine stalls. T _eng is an estimated engine torque, which is calculated from a map based on the throttle opening. Ne _idle + α also means the engine speed at which there is a possibility of engine stall, and Ne _idle + α + β also means the engine speed at which the clutch limit hydraulic pressure is calculated.

The ECU 60 determines that there is a possibility of engine stall when the engine speed after the engine speed reduction securing time Time _dec has elapsed becomes equal to or less than the engine stall determination threshold value Ne _idle + α. In this case, the ECU 60 restricts the target hydraulic pressure for clutch control to a hydraulic pressure (a limited hydraulic pressure) lower than the corresponding hydraulic pressure corresponding to the lever operation amount.

As described above, the clutch control device 60 </ b> A of the above embodiment drives the engine 13, the transmission 21, the clutch device 26 for connecting and disconnecting power transmission between the engine 13 and the transmission 21, and the clutch device 26. And a clutch actuator 50 for changing the clutch capacity, a clutch lever 4b for manually operating the clutch device 26, and an ECU 60 for calculating a control target value (target oil pressure) of the clutch capacity according to the operation amount of the clutch lever 4b. When performing the first control for connecting the clutch device 26 by operating the clutch lever 4b, the ECU 60 does not depend on the operation of the clutch lever 4b according to the engine speed and the estimated engine torque. A second control for limiting the clutch capacity (reducing the hydraulic pressure target value) is intervened.
Specifically, the ECU 60 obtains the limited clutch oil pressure at which the engine speed becomes equal to the engine stall determination threshold value _Neidle + α after the lapse of a predetermined time period Time _dec , compares it with the current target oil pressure, and intervenes the second control. I do.

According to this configuration, in the clutch-by-wire system, at the time of the first control for connecting the clutch device 26 by operating the clutch lever 4b, the engine stop speed and the throttle opening are always determined based on the engine stall determination threshold after the lapse of a predetermined time. Is determined, and if it is determined that the target hydraulic pressure exceeds the limited clutch hydraulic pressure (there is a possibility of engine stall), the second control that does not depend on the operation of the clutch lever 4b is intervened. I do. Accordingly, even when the engine is likely to stall when the rider's operation is prioritized, it is possible to intervene the second control before the engine stalls to limit the clutch capacity (set a half-clutch state). . For this reason, an unintended engine stall at the time of the clutch connection operation can be avoided.
In addition, since the above determination is always made and the possibility of engine stall is determined, accurate engine stall prediction based on the actual engine speed and the throttle opening can be performed, and the intervention determination of the second control (engine stall avoidance control) can be performed. Accuracy increases. Therefore, as compared with a case where the engine stall avoidance control is intervened early with a margin, it is possible to reduce the intervention frequency of the engine stall avoidance control and suppress the rider from feeling uncomfortable.

In the clutch control device 60A, the specified time Time _dec is a time required for disengaging the clutch.
That is, the time required for disengaging the clutch is counted from the time when the engine speed drops when the clutch is engaged, and the limited clutch oil pressure that will become the specified engine speed (lower limit) in the future (after the specified time _Dec ) is calculated. Then, it is determined whether or not the limited clutch hydraulic pressure becomes equal to or lower than the target hydraulic pressure. When it is determined that the limited clutch oil pressure becomes equal to or lower than the target oil pressure, the clutch capacity is limited before the engine stalls by switching to the second control independent of the operation of the clutch lever 4b. By setting the lower limit of the future engine speed and limiting the clutch capacity in this way, unintended engine stall can be avoided. Since the time required for disengaging the clutch (time lag) is taken into account, when connecting the clutch, if the clutch connection speed is too high and an engine stall is likely to occur, an instruction to immediately disengage the clutch will be given, Can be avoided.

In the clutch control device 60A, the ECU 60 intervenes the second control when the limited clutch oil pressure becomes equal to or less than the target oil pressure.
That is, when the limited clutch hydraulic pressure becomes equal to or less than the target hydraulic pressure, the clutch capacity is limited before the engine stalls by switching to the second control independent of the operation of the clutch lever 4b. By setting the lower limit of the future engine speed and limiting the clutch capacity in this way, unintended engine stall can be avoided.

In the clutch control device 60A, the clutch capacity limit value T _clutch set in the second control is determined by the difference β between the specified time Time _dec , the clutch connection rotation speed Ne _idle + α + β, and the engine stall determination threshold Ne _idle + α. And the estimated engine torque.
In this case, the ECU 60 sets the limit value T _clutch of the clutch capacity separated from the clutch operation based on the change rate based on the specified time Time _dec and the difference β between the engine speed and the engine estimated torque. As a result, the clutch capacity can be limited in accordance with the prediction of the future engine speed, and engine stall can be avoided.

In the clutch control device 60A, the clutch capacity limit value T _clutch set in the second control may be calculated based on a limit value map (see FIG. 10) that changes according to the engine speed.
In this case, the ECU 60 sets a limit value T _clutch of the clutch capacity separated from the clutch operation based on a limit value map that changes according to the engine speed. As a result, the clutch capacity can be limited in accordance with the prediction of the future engine speed, and engine stall can be avoided.

In the clutch control device 60A, the clutch capacity limit value T _clutch set in the second control is determined by comparing the first limit value A with the second limit value B.
In this case, the ECU 60 calculates the first limit value A calculated from the rate of change based on the difference β between the prescribed time _Dec and the engine speed and the estimated engine torque, and the limit value map that changes according to the engine speed. The second limit value B is compared with, for example, a relatively low value is set as the clutch capacity limit value T _clutch . This makes it possible to set a suitable limit value according to the engine speed and the like. Then, the clutch capacity can be limited according to the prediction of the future engine speed, and engine stall can be avoided.

The present invention is not limited to the above-described embodiment.For example, the present invention is not limited to application to a configuration in which the clutch is connected by increasing the hydraulic pressure and the clutch is disconnected by reducing the hydraulic pressure. The present invention may be applied to a configuration in which a clutch is connected to reduce the number of clutches.
The clutch operator is not limited to the clutch lever 4b, but may be a clutch pedal or other various operators.
The present invention is not limited to the application to a saddle-ride type vehicle in which the clutch operation is automated as in the above-described embodiment, and the gear shift is performed by adjusting the driving force without performing the manual clutch operation under predetermined conditions, based on the manual clutch operation. The present invention is also applicable to a saddle-ride type vehicle having a so-called clutchless transmission.
The saddle-ride type vehicle includes all vehicles in which a driver rides across a vehicle body, and includes not only motorcycles (including motor-driven bicycles and scooter-type vehicles) but also three wheels (one front wheel and two rear wheels). In addition, vehicles including front two-wheel and rear one-wheel vehicles) or four-wheel vehicles are also included, and vehicles including an electric motor as a prime mover are 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 spirit of the present invention.

1. Motorcycles (saddle-riding type vehicles)
4b Clutch lever (clutch operator)
4c Clutch lever operation amount sensor (clutch operation amount sensor)
13 engine 21 transmission 26 clutch device 50 clutch actuator 60 ECU (control unit)
60A Clutch control device A First limit value B Second limit value Ne Engine speed _Neidle + α Engine stall threshold _Neidle + α + β Clutch _engagement speed T _clutch limit value _Teng engine estimated torque Time _dec Specified time, engine speed reduction Secure time β difference

Claims

Engine and
A transmission,
A clutch device for connecting and disconnecting power transmission between the engine and the transmission;
A clutch actuator that drives the clutch device to change a clutch capacity;
A clutch operator for manually operating the clutch device,
A control unit that calculates a control target value of the clutch capacity according to an operation amount of the clutch operator;
With
The control unit is configured to perform the first control for connecting the clutch device by operating the clutch operator, according to an engine speed and an estimated engine torque, regardless of the operation of the clutch operator. A clutch control device intervening a second control for limiting the clutch capacity.
The control unit obtains a limited clutch oil pressure at which the engine speed becomes an engine stall determination threshold after a predetermined time elapses, compares it with a current target oil pressure, and intervenes in the second control. The clutch control device according to claim 1.
The clutch control device according to claim 2, wherein the specified time is a time required for disengaging the clutch.
4. The clutch control device according to claim 3, wherein the control unit intervenes the second control when the limited clutch hydraulic pressure becomes equal to or less than a target hydraulic pressure. 5.
The clutch capacity limit value set in the second control is calculated based on the specified time, a difference between a clutch engagement rotation speed and the engine stall determination threshold, and the engine estimated torque. The clutch control device according to claim 3 or 4, wherein
The clutch control device according to claim 3, wherein the clutch capacity limit value set in the second control is calculated based on a limit value map that changes according to the engine speed. .
The limit value of the clutch capacity set in the second control is a first value calculated based on the specified time, a difference between a clutch engagement rotation speed and the engine stall determination threshold, and the engine estimated torque. The clutch control device according to claim 6, wherein the clutch control device is determined by comparing a limit value with a second limit value calculated based on the limit value map.