JPH09269019A - Automatic clutch device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent occurrence of unbalanceness of amounts of operation oil in automatic and manual operation oil supply mechanisms and abrupt starting of a vehicle at the changeover from automatic to manual operation. SOLUTION: A changeover cylinder 30 which has a piston 33 energized in one side of a cylinder 31 by means of a spring 32 is arranged between an operation oil passage 9 of a manual operation oil supply mechanism 10 in an automatic clutch device for a vehicle that can be manually operated and operation oil passages 16, 23 of an automatic operation oil supply mechanism 21 and a slave cylinder 4 for operating a frictional clutch. The operation oil passage 9 of the manual operation oil supply mechanism 10 is connected to the side of the piston 33 of the cylinder 30, while the operation oil passages 16, 23 of the automatic operation oil supply mechanism 21 and the slave cylinder 4. Hydraulic pressure due to operation of a clutch pedal 5 is transmitted to the slave cylinder 4 by movement of the piston 33.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an automatic clutch device for a vehicle which can be operated manually.

[0002]

2. Description of the Related Art An automatic transmission that electronically shifts a transmission electronically according to operating conditions such as engine speed, accelerator opening, vehicle speed, etc., and also controls a vehicle by automatically connecting and disconnecting a mechanical friction clutch. Is well known, and in such an automatic transmission, an automatic transmission of a vehicle in which the mechanical friction clutch can be manually operated is known from, for example, Japanese Utility Model Publication No. 4-8023. That is, the automatic transmission described in the above publication is suitable for starting under special conditions such as starting over obstacles, starting up a steep slope, starting up on a snowy road, etc. such that the friction clutch cannot be connected or disconnected and the vehicle cannot start. Under these special conditions, the automatic clutch control is stopped so that the clutch can be engaged and disengaged by manual operation.This is output to the control system of the automatic transmission during gear shifting. Means for shutting off the clutch actuation signal when the clutch pedal is depressed, a control valve that responds to the clutch pedal and supplies the working fluid to the clutch booster (actuator such as slave cylinder), and selects the working fluid to the booster. It is equipped with a double check valve that feeds the material.

On the other hand, the transmission is operated manually, the clutch only, and shall automatically (auto) disconnects depending essentially shifting state and the driving state, the driver thereto
Manually at the will of, or when automatic operation is disabled
An automatic clutch device as shown in FIGS. 3 and 4 that can be operated (manually) has been put into practical use. That is, this device is rotated about a as a fulcrum, and the lower end is connected to the upper end of the clutch release fork 3 for pushing the release bearing 2 of the friction clutch 1 and the slave cylinder 4 connected to the upper end of the clutch release fork 6 and the booster mechanism 6 operated by depressing the clutch pedal 5. , A manual operation hydraulic oil supply mechanism 10 including a master cylinder 8 having an oil tank 7 and a hydraulic oil pipe 9 connected to the cylinder 8, and an oil tank 11 and a pipe 12 which are connected to each other and are driven by a motor 13. The gear pump 14, a hydraulic oil line 16 connected to the gear pump 14 via a check valve 15, a relief valve 18 provided in a line 17 extending from between the gear pump 14 and the check valve 15 to the oil tank 11, and From the hydraulic oil line 16 to the oil tank 11
To the slave cylinder 4 via a switching mechanism 22 and a hydraulic oil supply mechanism 21 for automatic operation, which is composed of a solenoid valve 20 provided in a return pipe 19 leading to It is connected by 23. As the switching mechanism 22, for example, an electromagnetic switching valve 22 ′ as shown in FIG. 4 is used, and the hydraulic oil pipe 9 of the manual operation hydraulic oil supply mechanism 10 and the hydraulic oil pipe of the automatic operation hydraulic oil supply mechanism 21 are used. 16 and are connected to the slave cylinder 4.

With the above structure, when the operation of the friction clutch 1 is switched from manual operation to automatic operation, for example, the switching mechanism 22 (electromagnetic switching valve 22 ') is manually or automatically switched to the automatic side and the motor is operated. When the gear pump 14 is driven by 13, the hydraulic fluid opens the check valve 15 and enters the slave cylinder 4 in the pipeline 23 through the hydraulic fluid pipeline 16 and the switching mechanism 22 (electromagnetic switching valve 22 '), causing the piston 4a to move. 4, the clutch release fork 3 is rotated clockwise around the fulcrum a as a result of which the friction release clutch 2 is pushed to the left to disconnect the friction clutch 1. The piston
4a has moved a predetermined stroke
If a position sensor (not shown) provided on the
The power of the pump 13 is turned off and the rotation of the pump 14 is stopped.
After the power supply to the motor 13 is cut off and the gear pump 14 is stopped, the solenoid valve 20 is controlled and opened to adjust the return speed of the hydraulic oil, so that the hydraulic oil in the slave cylinder 4 is generated by the spring in the friction clutch 1. Piston 4 via release bearing 2 and clutch release fork 3
By the return of a, the oil tank 1 from the pipeline 23 and the hydraulic oil pipeline 16 through the return pipeline 19 and the solenoid valve 20.
Return to 1. As a result, the friction clutch 1 becomes "contact".

Similarly, when the switching mechanism 22 is manually or automatically switched to, for example, the manual mode, the switching mechanism 22, that is, the electromagnetic switching valve 22 'is switched to the manual side as shown in FIG. If you step on,
The booster mechanism 6 operates and the piston 8 in the master cylinder 8
a is moved to the left in FIGS. 3 and 4, and hydraulic oil is introduced into the slave cylinder 4 through the hydraulic oil line 9 and the switching mechanism 22 (electromagnetic switching valve 22 ') through the line 23, and the piston 4a is moved to the position shown in FIG. 4, the clutch release fork 3 is rotated clockwise around the fulcrum a as a result of which the friction release clutch 2 is pushed to the left to disconnect the friction clutch 1. When the clutch pedal 5 is returned, the piston 8a in the master cylinder 8 will move to the cylinder 8 and the booster mechanism 6.
3 and 4 is returned to the right by an internal spring, and at the same time, the hydraulic oil in the slave cylinder 4 is returned by the return of the piston 4a via the release bearing 2 and the clutch release fork 3 by the spring in the friction clutch 1. Returns to the oil tank 7 through the master cylinder 8 and the pipe 23 and the hydraulic oil pipe 9. As a result, the friction clutch 1 becomes "contact".

By the way, it has been found that the ones operated by hydraulic oil as shown in FIGS. 3 and 4 have the following problems when the electromagnetic switching valve 22 'as shown in FIG. 4 is used as the switching mechanism. did. (1) Imbalance of the amount of hydraulic oil in both hydraulic oil supply mechanisms When the friction clutch 1 is in the “contact” state, that is, the piston 4a of the slave cylinder 4 is switched between the automatic operation and the manual operation in FIGS. If the operation is performed when there is no hydraulic oil in the slave cylinder 4 at the left end, no malfunction occurs because there is no hydraulic oil flowing between the hydraulic oil supply mechanisms 10 and 21, but when the clutch 1 is "disengaged", That is,
If the piston 4a of the slave cylinder 4 is located at the position shown in FIG. 3 or FIG. 4 or to the right of FIG. 4 and the slave cylinder 4 is filled with hydraulic oil, the switching operation is performed when both of the hydraulic oil supply mechanisms 10, There is a problem that hydraulic oil flows back and forth between 21 and one of the oil tanks 7 and 11 overflows and the other becomes empty.

For example, after depressing the clutch pedal 5 to disengage the friction clutch 1 (at this time, the slave cylinder 4 is filled with hydraulic oil from the oil tank 7), the electromagnetic switching valve 22 'is automatically turned on. When switched, the pipe line 23 connected to the slave cylinder 4 is disconnected from the hydraulic oil line 9 connected to the oil tank 7, and is connected to the return line 19 of the automatic operation hydraulic oil supply mechanism 21. To be done. Therefore, in this state, when the solenoid valve 20 is opened as described above, the hydraulic oil in the slave cylinder 4 flows into the oil tank 11 through the return pipe 19 and the friction clutch 1 becomes "contact". This phenomenon means that the hydraulic oil in the oil tank 7 has been returned to the oil tank 11, and if the above operation is repeated many times, the oil tank 7 becomes empty as described above and the oil An event may occur in which the hydraulic oil overflows from the tank 11.

(2) Rapid start of vehicle at the time of switching from automatic operation to manual operation As described above, there is no problem if switching from automatic operation to manual operation is performed when the friction clutch 1 is in the "contact" state. When the clutch 1 is switched to the manual operation by the automatic operation after the clutch 1 is disengaged, the master cylinder 8 and the oil tank 7 are in communication with each other when the clutch pedal 5 is not stepped on. The hydraulic oil in the slave cylinder 4 is supplied to the pipeline 23, the electromagnetic switching valve 2
2 ′ and the hydraulic oil line 9 are all returned to the oil tank 7, and as a result, the friction clutch 1 suddenly becomes “contact”, and if the gear of the transmission is engaged at this time, the vehicle may suddenly start. is there.

In order to prevent the occurrence of the above situation, it is conceivable to modify the master cylinder 8 and close the oil passage between the oil tank 7 and the master cylinder 8 with the clutch pedal 5 released. Then, for example, when the air is removed from the slave cylinder 4 to the master cylinder 8 after the vehicle is assembled, there is a problem that the air that has risen to the master cylinder 8 cannot be removed. In addition, both the oil tanks 7 and 1
1 may be integrated, but the oil tank 7 needs to be positioned above the master cylinder 8 in order to release air when air is mixed into the manually operated hydraulic oil supply mechanism 10. Yes, the oil tank 11
However, in order to avoid the so-called clutch disengagement from becoming worse due to air mixing and an increase in pipe line resistance, the vicinity of the pump 14 is desirable in some cases, and the integration is also not preferable. In addition, a switching mechanism 22 such as the electromagnetic switching valve 22 '.
It is conceivable that the condition of "clutch engagement" is used as the condition for switching the above. Since the connection position of the friction clutch changes due to wear of the clutch plate and the like, it is difficult to detect the position with a switch or the like. B. Detects the current state of the friction clutch (whether it is in the contact direction or in the disengagement direction) and the driving state of the vehicle, and the combination of these detects the clutch connection point in the processing in the electronic controller. However, it is possible that the structure becomes complicated and the manual operation is hindered in the unlikely event that the electronic system fails.

[0010]

SUMMARY OF THE INVENTION Therefore, an object to be solved by the present invention is to provide an automatic clutch device for a vehicle which can also be operated manually, while avoiding remodeling of the master cylinder and processing in the electronic control. An object of the present invention is to provide an automatic clutch device for a vehicle capable of preventing an imbalance in the amount of hydraulic oil in both hydraulic oil supply mechanisms and a rapid start of the vehicle when switching from automatic operation to manual operation.

[0011]

An automatic clutch device for a vehicle according to the present invention for solving the above problems includes a slave cylinder for connecting and disconnecting a friction clutch.
A hydraulic oil supply mechanism for automatic operation that is operated by a pump,
In a vehicle automatic clutch device configured to selectively pipe-connect a hydraulic oil supply mechanism for manual operation which is operated by a clutch pedal, the hydraulic oil line of the hydraulic oil supply mechanism for manual operation , A switching cylinder having a piston urged by a spring on one side of the cylinder is provided between the automatic operation hydraulic oil supply mechanism and both hydraulic oil lines of the slave cylinder, and the piston side of the cylinder is provided. To the hydraulic oil line of the manual operation hydraulic oil supply mechanism and to the spring side of both the automatic operation hydraulic oil supply mechanism and the hydraulic oil lines of the slave cylinder to connect the hydraulic oil pressure by the depression of the clutch pedal to The first invention is characterized in that it is transmitted to the slave cylinder by the movement of the piston, and the switching system in the first invention. And a second piston that is pressed by a spring toward one end of the cylinder when not in operation, and a second piston that is biased by the spring in the same piston direction while maintaining a distance from the first piston, A hydraulic fluid line of the hydraulic fluid supply mechanism for manual operation is provided on the first piston side of the cylinder, and the automatic operation is provided between the pistons.
And a second invention in which both hydraulic oil pipes of the slave cylinder are connected to the biasing spring side of the second piston.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2, the same reference numerals as those in Figs. 3 and 4 indicate the same members, and the description thereof will be omitted. In the vehicle auto-clutch device of the present invention shown in FIGS. 1 and 2, switching cylinders 30 and 40 are provided in place of the switching mechanism 22 and the electromagnetic switching valve 22 'shown in FIGS. 3 and 4, respectively. It was done. The switching cylinder 30 shown in FIG. 1 has a piston 31 which is biased by a spring 32 on one side 31a of the cylinder 31 inside the cylinder 31, and the piston 33 has the one side 31a.
The convex portion 33a is formed on the side facing to the spring 3 when not operating.
Even when pressed to one side 31a of the cylinder 31 by 2,
A gap that facilitates pressing of the piston 33 can be formed between the one side 31a and the piston 33.

The pipe for the switching cylinder 30 is connected to the piston 33 side of the cylinder 31, that is, the one side 31a.
The hydraulic oil line 9 of the manual operation hydraulic oil supply mechanism 10, and the hydraulic oil line 16 of the automatic operation hydraulic oil supply mechanism 21 and the slave cylinder 4 on the spring 32 side.
The hydraulic oil pipelines 23 are connected to each other. In the vehicular auto clutch device of FIG. 1 configured as described above,
When switching the operation of the friction clutch 1 from, for example, manual operation to automatic operation, the motor 13 is turned on manually or automatically, and the gear pump 14 is driven by the motor 13. The open hydraulic oil pipe line 16 and the pipe line 23 enter the slave cylinder 4 and push the piston 4a to the right in FIG. 1, whereby the friction clutch is "disengaged" via the clutch release fork and the release bearing as described above. At this time, the spring 32 side of the cylinder 31 of the switching cylinder 30 is connected to the conduit 1
The pressure becomes the same as that in 6, and the piston 33 is only pressed to the one side 31a of the cylinder 31, and there is no problem.

When the power to the motor 13 is cut off, the gear pump 14 is stopped, and the solenoid valve 20 is opened while controlling the return speed of the hydraulic oil, the hydraulic oil in the slave cylinder 4 will be stored in the friction clutch 1. By the return of the piston 4a via the release bearing and the clutch release fork by the spring, the pipe 23 and the hydraulic oil pipe 16 return to the oil tank 11 via the return pipe 19 and the solenoid valve 20. As a result, the friction clutch 1 becomes "contact".

When switching from automatic operation to manual operation, if the clutch pedal 5 is depressed with the power to the motor 13 turned off, the piston 8a in the master cylinder 8 is moved to the left in FIG. The oil is press-fitted into the cylinder 31 from one side 31a of the cylinder 31 of the switching cylinder 30 via the hydraulic oil line 9. As a result, the piston 33 moves to the left in the cylinder 31 against the spring 32, and the hydraulic oil on the spring 32 side of the cylinder 31 is pushed out to the hydraulic oil pipe lines 16 and 23. However, since the hydraulic oil pipe 16 side is shut off by the check valve 15 and the electromagnetic valve 20, almost the entire amount of the hydraulic oil pipe 16 enters the slave cylinder 4 through the pipe 23 and pushes the piston 4a to the right in FIG.
As a result, the friction clutch is "disengaged" via the clutch release fork and the release bearing as described above.

When the clutch pedal 5 is returned, the piston 8a in the master cylinder 8 returns to the right in FIG. 1 by the spring of the cylinder 8 and the like, and at the same time, the release bearing and the clutch release fork by the spring in the friction clutch 1 are moved. By the return of the piston 4a via the hydraulic fluid, the hydraulic oil in the slave cylinder 4 returns to the cylinder 31 of the switching cylinder 30 via the pipe line 23, and the return hydraulic oil and the spring 32 cause the piston 33 to move to the one side 3
Since it moves to 1a, the piston 33 and the one side 31
The hydraulic oil between the points a returns to the oil tank 7 via the master cylinder 8. As a result, the friction clutch 1 becomes "contact".

The switching cylinder 40 shown in FIG. 2 is in contact with a first piston 43 biased by a spring 42 to one side 41a of the cylinder 41 and a stopper 44 formed in the center of the cylinder 41 in the cylinder 41. The second piston 46, which is biased by the spring 45, is installed inside.
A convex portion 43a is formed on the first piston 43 on a side facing the one side 41a, and the cylinder 42 is fixed by the spring 42 when not operating.
When one side 41a is pressed, the one side 41a
A gap that facilitates the pressing of the piston 43 can be formed between the first piston 43 and the first piston 43.

The piping for the switching cylinder 40 is connected to the first piston 43 side of the cylinder 41, that is, the one side 4 thereof.
1a is the hydraulic oil conduit 9 of the manual operating hydraulic oil supply mechanism 10, the hydraulic oil conduit 16 of the automatic operating hydraulic oil supply mechanism 21 is provided between the pistons 43 and 46, and the second piston is attached. Both hydraulic oil pipe lines 23 of the slave cylinder are connected to the bias spring side.

In the vehicle automatic clutch device of FIG. 2 configured as described above, when the operation of the friction clutch 1 is switched from manual operation to automatic operation, for example,
When the motor 13 is turned on manually or automatically and the gear pump 14 is driven by the motor 13, the working oil opens the check valve 15 and passes through the working oil conduit 16 to both pistons 43, 46 in the cylinder 41 of the switching cylinder 40. It is pressed in between and pushes both pistons 43 and 46. This allows the second
The piston 46 moves to the left in FIG. 2 against the spring 45,
The hydraulic oil in the cylinder 41 having the spring 45 is press-fitted into the slave cylinder 4 through the pipe line 23. Therefore, the piston 4
1a is pushed to the right in FIG. 1, whereby the friction clutch is "disengaged" via the clutch release fork and the release bearing as described above.

When the power to the motor 13 is cut off, the gear pump 14 is stopped, and the solenoid valve 20 is controlled and opened in order to adjust the return speed of the hydraulic oil, the hydraulic oil in the slave cylinder 4 flows through the passage 23. After that, it returns to the chamber in which the spring 45 of the cylinder 41 is provided, and the hydraulic oil and spring 45
Thus, the second piston 46 moves until it comes into contact with the stopper 44 in FIG. By this, both pistons 43, 4
The hydraulic oil between 6 returns to the oil tank 11 from the hydraulic oil line 16, the return line 19 and the solenoid valve 20. As a result, the friction clutch 1 becomes "contact".

When switching from the automatic operation to the manual operation, if the clutch pedal 5 is depressed with the power supply to the motor 13 turned off, the piston 8a in the master cylinder 8 is moved leftward in FIG. Oil is press-fitted into the cylinder 41 from one side 41a of the cylinder 41 of the switching cylinder 40 through the hydraulic oil line 9. As a result, the first piston 43 moves to the left in the cylinder 41 against the spring 42, and the second piston 46 moves to the left in FIG. 2 against the spring 45. The hydraulic oil is press-fitted into the slave cylinder 4 through the pipe line 23. Therefore, the piston 4a is pushed to the right in FIG. 1, which causes the friction clutch to be "disengaged" via the clutch release fork and the release bearing as described above. At this time, the hydraulic oil between the pistons 43 and 46 is also the hydraulic oil line 16
However, the hydraulic oil conduit 16 side is blocked by the check valve 15 and the solenoid valve 20 and does not flow.

When the clutch pedal 5 is returned, the piston 8a in the master cylinder 8 returns to the right in FIG. 2 by the spring of the cylinder 8 and the like, and at the same time, the release bearing and the clutch release fork by the spring in the friction clutch 1 are moved. Due to the return of the piston 4a via the hydraulic cylinder, the hydraulic oil in the slave cylinder 4 returns to the chamber in the cylinder 41 of the switching cylinder 40 in which the spring 45 is provided via the pipe line 23, and the return hydraulic oil and the spring 45 cause the second oil to flow to the second chamber. The piston 46 returns until it contacts the stopper 44, and the first
Since the piston 43 moves to the one side 31a by the hydraulic oil and the spring 42, the hydraulic oil between the first piston 43 and the one side 41a returns to the oil tank 7 via the master cylinder 8. As a result, the friction clutch 1 becomes "contact".

[0023]

INDUSTRIAL APPLICABILITY The present invention provides a hydraulic oil line for a manual operation hydraulic oil supply mechanism and both hydraulic oil lines for an automatic operation hydraulic oil supply mechanism and a slave cylinder in a vehicle automatic clutch device that can also be manually operated . A switching cylinder having a piston that is biased by a spring is disposed on one side of the cylinder, a hydraulic oil line of the hydraulic fluid supply mechanism for manual operation is provided on the piston side of the cylinder, and a hydraulic fluid line is provided on the spring side. A first invention in which both the automatic operation hydraulic oil supply mechanism and the hydraulic oil pipes of the slave cylinder are connected to each other, and the switching cylinder of the first invention is pressed by a spring to one end side of the cylinder when not in operation. A switching cylinder having one piston and a second piston biased by a spring in the direction of the piston while keeping a distance from the piston, and the first piston of the cylinder. Wherein the hydraulic fluid pipeline of the manually operated hydraulic fluid feed mechanism to the side, also the hydraulic fluid pipeline of the automatic operation for the hydraulic oil supply mechanism between the two pistons, further biasing spring side of the second piston slave cylinder According to the second aspect of the present invention in which the hydraulic oil pipeline is connected, a switching cylinder having a built-in piston is provided instead of the conventional electromagnetic switching valve, so that the operation between the automatic and manual hydraulic oil supply mechanisms and the slave cylinder is performed. The oil pipe line does not directly communicate, but will be connected via the switching cylinder,
Therefore, even if the automatic operation and the manual operation are switched at any time, the hydraulic oil returning from the slave cylinder does not flow into either of the hydraulic oil supply mechanisms, so that the amount of hydraulic oil in both hydraulic oil supply mechanisms is Balance is always maintained,
Further, similarly, there is no possibility that the hydraulic oil returned from the slave cylinder will flow out to the communicating oil tank and the friction clutch will suddenly become “engaged” and the vehicle will rapidly start. Further, the switching cylinder has a simple structure and can be easily replaced with the electromagnetic switching valve, can be manufactured at a lower cost than the modification of the master cylinder, and has no difficulty in bleeding the air. Further, in order to cope with the above-mentioned problem, the electromagnetic switching valve is replaced with the switching cylinder of the present invention regardless of the processing in the electronic control, so that safety in the event of failure of the electronic control system is achieved by taking measures in the category of fluid machinery. There is also an effect that it can be guaranteed.

[Brief description of drawings]

FIG. 1 is a fluid circuit diagram of an example of a vehicle auto-clutch device of the present invention.

FIG. 2 is a fluid circuit diagram of another example of the vehicle auto-clutch device of the present invention.

FIG. 3 is an overall view of a conventional vehicle automatic clutch device.

FIG. 4 is a fluid circuit diagram of the vehicle automatic clutch device shown in FIG.

[Explanation of symbols]

1 Friction clutch 2 Release bearing 3
Release fork 4 Slave cylinder 5 Clutch pedal 7,
11 Oil Tank 8 Master Cylinder 9, 16, 23 Hydraulic Oil Pipeline
12, 17 Pipe line 10 Manual operation hydraulic oil supply mechanism 13 Motor 14 Gear pump 15 Check valve 18 Relief valve 19 Return pipeline 20 Solenoid valve 21 Automatic operation hydraulic oil supply mechanism 22 Switching mechanism 22 'Electromagnetic switching valve 30, 40 Switching cylinder 31, 41 Cylinder 32, 42, 45 Spring 33 Piston 43
First piston 46 Second piston.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhiko Kobayashi 4-1-1, Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Transtron Co., Ltd. 1-1 No. 1 within Transtron Co., Ltd. (72) Nobuo Sugamura No. 4-1-1, Kamiodanaka, Nakahara-ku, Kawasaki-shi, Kanagawa Inside Transtron Co., Ltd.

Claims (3)

[Claims] 1. A slave cylinder for connecting and disconnecting a friction clutch, wherein a hydraulic fluid supply mechanism for automatic operation which is operated by a pump and a hydraulic fluid supply mechanism for manual operation which is operated by a clutch pedal are selectively provided for the cylinder. In a vehicle automatic clutch device configured to be capable of pipe connection, between the hydraulic oil pipe of the hydraulic oil supply mechanism for manual operation and both the hydraulic oil pipes of the automatic operation hydraulic oil supply mechanism and the slave cylinder, A switching cylinder having a piston urged by a spring is arranged on one side of the cylinder, the hydraulic oil conduit of the manual operation hydraulic oil supply mechanism is provided on the piston side of the cylinder, and the automatic operation is provided on the spring side. each connecting both the hydraulic fluid pipeline of use hydraulic oil supply mechanism and the slave cylinder, by depression of the clutch pedal It is transmitted to the slave cylinder of dynamic pressure by the movement of the piston automatic clutch device for a vehicle according to claim. 2. A slave cylinder for connecting and disconnecting a friction clutch, wherein an automatic operation hydraulic oil supply mechanism operated by a pump and a manual operation hydraulic oil supply mechanism operated by a clutch pedal are selectively provided for the cylinder. In a vehicle automatic clutch device configured to be capable of pipe connection, between the hydraulic oil pipe of the hydraulic oil supply mechanism for manual operation and both the hydraulic oil pipes of the automatic operation hydraulic oil supply mechanism and the slave cylinder, A switching cylinder having a first piston which is pressed by a spring on one end side of the cylinder when not in operation and a second piston which is biased by a spring in the direction of the first piston while maintaining a distance from the first piston is provided. the Oh hydraulic fluid pipeline of the manually operated hydraulic fluid feed mechanism to said first piston side of the cylinder, also between the pistons The hydraulic fluid pipeline of the preparative operations for the hydraulic oil supply mechanism, further said second connecting pistons hydraulic fluid pipeline of the slave cylinder biasing spring side of the piston a hydraulic pressure by the operation of depression of the clutch pedal and the pump Is transmitted to the slave cylinder by the movement of the vehicle automatic clutch device. 3. The vehicle automatic clutch device according to claim 2, wherein the switching cylinder is provided with a stopper for the second piston in the cylinder.