JPH0131054B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a clutch release device for a vehicle.

A clutch release device for a vehicle that pushes the release lever of a friction clutch, which is normally engaged by the force of a spring, in the clutch release direction in response to depression of the clutch pedal, and is an open sensor type controlled by the clutch pedal. A device having a hydraulic booster and a transmission mechanism that mechanically transmits the output of the hydraulic booster to the release lever is conventionally known. By manually adjusting the transmission mechanism so that no unwanted pressing force is applied to the release lever, slippage of the clutch disk due to wear of the clutch disk is prevented.

However, in vehicles such as industrial vehicles that frequently use half-clutches and where the clutch disc is subject to severe wear, the above adjustments must be made frequently.
There were some troublesome flaws.

The above disadvantages can be solved by automating the above adjustment, but when such conventional technology is used, there is a master cylinder operated by a hydraulic booster and a release cylinder operated by the hydraulic pressure generated by this master cylinder. This makes the device larger and more expensive.

It is an object of the present invention to provide a self-adjusting mechanism within the hydraulic booster to deal with clutch disc wear, which eliminates the need for manual adjustment and which is smaller and cheaper than conventional self-adjusting techniques. It is about becoming something.

Therefore, in order to achieve the above-mentioned object, the present invention includes a piston that is slidably fitted into an output rod portion of a power piston of a hydraulic booster.
engaging the piston with the hydraulic booster side end of the transmission mechanism, and communicating the pressure chamber formed in the output rod portion by the piston with the drain chamber of the hydraulic booster through a passage;
A normally open valve is provided that shuts off the passage in conjunction with the operation of the input piston of the hydraulic booster, and the normally open valve and a portion of the passage are provided within the tip of the input piston that is emptied into the pressure chamber. A spring tensioned between the piston and the output rod in the pressure chamber so that the input piston is not biased displaces the piston toward the outside of the output rod.

In this configuration, when the clutch pedal is depressed, the normally open valve closes and the pressurizer becomes a closed chamber, and the output rod portion and the piston are integrated, so that the clutch is released. Furthermore, when the clutch pedal is released, the normally open valve opens and the pressure chamber communicates with the drain chamber, allowing the piston to move backward relative to the output rod, so the piston wears out in proportion to the amount of wear on the clutch disc. The spring force of the clutch causes it to be displaced backward within the output rod, thereby preventing any unwanted pressing force from being applied to the release lever of the friction clutch.

When the device is installed on a vehicle, the air in the pressure chamber must be removed from the piston because the hydraulic booster is an open center type and the working fluid always flows through the drain chamber. This can be easily achieved by reciprocating the

Furthermore, the increasing wear on the friction clutch forces the piston inwardly into the output rod, which increases the spring force in the pressure chamber.
Since this spring force is not applied to the input piston, there is an advantage that there is little change in the input required to operate the input piston, that is, the clutch pedal depression force.

Embodiments of the present invention will be described below based on the drawings. Reference numeral 10 denotes a well-known diaphragm spring type friction clutch installed in the vehicle drive system, which is normally engaged by the force of the diaphragm spring, and is activated by pushing the release lever 11 to the left against the diaphragm spring. The camera is released.

The clutch release device 20 includes a clutch pedal 30 and a transmission mechanism 70 that mechanically transmits the output of the hydraulic booster 40 to the release lever 11.

The hydraulic booster 40 includes a fixed housing 42 having a stepped cylinder hole 41, an input piston 43, and a small diameter portion 41 of the stepped cylinder hole 41.
a small diameter base 44a slidably fitted in the stepped cylinder hole 41, a large diameter part 44b slidably fitted in the large diameter part 41b of the stepped cylinder hole 41, and an output rod part 44f located on the left side of the large diameter part 44b. has. This output rod portion 44f slidably passes through a plug 46 that is fitted and fixed in the left end opening of the stepped cylinder hole 41. The annular working chamber 47 on the outer periphery of the power piston 44 is connected to the pump 48 so that the working fluid discharged by the pump 48 flows into the working chamber 47, and the working fluid flowing into the working chamber 47 from the pump 48 flows into the small diameter portion 43b of the input piston 43. It is designed to flow to a drain chamber 50 on the left side of the power piston 44 through a normally open control valve 49 consisting of the power piston 44 and the power piston 44 . That is, the small diameter portion 43 of the input piston 43
b is slidably fitted into an inner hole 44c of the power piston 44, and at the fitting portion between the two, an annular groove 44e is formed on the inner periphery of the power piston 44 and communicates with the working chamber 47 via a hole 44d. is formed,
On the other hand, the small diameter portion 43b of the input piston 43 has an annular groove 44g and an annular groove 43f communicating with the drain chamber 50 through the hole 44h. The control valve 4 is formed so as to reduce the communication area of the normally open control valve 4.
9 is made up of. The drain chamber 50 is connected to a reservoir 51, and a return spring 52 is installed inside the drain chamber 50 to bias the power piston 44 to the right. The end of the rightward movement stroke of the input piston 43 is defined by a pin 53 that passes through the hole 43e with some play and has both ends fitted into the hole 44i of the power piston 44 with some play. The input piston 43 is in communication with the clutch pedal 30 by a push rod 54.

The output rod portion 44f is hollow according to the present invention, and the large diameter hole 44 of the output rod portion 44f is hollow.
A piston 55 that comes into contact with the right end of the rod 71 of the transmission mechanism 70 is slidably fitted into the piston 55. This piston 55 is slidably fitted. This piston 55 allows the output rod portion 44 to
The pressure chamber 56 formed in f is connected to the input piston 43
A normally open valve mechanism 5 located inside the left end (tip)
7 performs communication/blocking control with respect to the drain chamber 50. The valve mechanism 57 consists of a valve body 58 of the valve chamber 43c, a spring 59, and a rod 60 disposed with play in the hole 43d. The spring 63 biases the piston 55 to the left, but the input piston 43
will not be biased to the right.

The transmission mechanism 70 includes a rod 71 and a rod 7.
A lever 73 is pivotally attached to the left end of the rod 71 and rotates about a fulcrum 72 when the rod 71 moves leftward, a lever 74 is integrated with this lever 73, and a lever 74 is pushed leftward by this lever 74. It consists of a release bearing 75 that pushes the release lever 11 leftward.

The operation of the above configuration will be explained next.
The state shown in the drawing is a state in which the clutch pedal 30 is released.

When the clutch pedal 30 is depressed in the state shown in the drawing, the input piston 43 of the hydraulic booster 40 is actuated, that is, pushed to the left. Due to the operation of this input piston 43, the valve mechanism 5
The valve body 58 of No. 7 is in contact with the valve seat 43h on the input piston 43 by the spring 59, and in the state shown, the valve body 58 of No. 7 is in contact with the valve seat 43h on the input piston 43.
The pressure chamber 56, which was communicating with the drain chamber 50 through the valve chamber 43c, the hole 43d, the hole 43e, the annular groove 44g, and the hole 44h, is cut off from the drain chamber 50 and becomes a closed chamber. On the other hand, the communication area between the annular groove 44e of the power piston 44 and the annular groove 43f of the input piston 43 decreases due to the operation of the input piston 43, but the value that this communication area brings to the pressure increase in the working chamber 47 depends on the valve mechanism. This is after 57 is closed. The operation of the input piston 43 after the valve mechanism 57 is closed is such that the piston 55 moves to the left with respect to the output rod portion 44f so as to compensate for the reduced volume of the pressure chamber 56 due to the entry of the input piston 43 into the pressure chamber 56. Therefore, the input piston 43 takes over the operation, thereby increasing the pressure in the working chamber 47. The operating force generated in the power piston 44 by increasing the pressure in the working chamber 47 is transmitted to the rod 71 via the working fluid in the pressure chamber 56 and the piston 55. The pressure within the pressure chamber 56 is responsive to the actuation force of the power piston 44;
This pressure acts on the input piston 43 and pushes the input piston 43 to the right, generating a pedal reaction force here. The input piston 43 slides relative to the power piston 44 depending on the magnitude relationship between this pedal reaction force and the input from the rod 54, thereby adjusting the pressure in the working chamber 47 to a pressure corresponding to the pedal depression force. Ru.

The increase in pressure in the working chamber 47 causes the input piston 43, power piston 44, piston 55, and rod 71 to integrally move to the left, causing the release bearing 75 to connect the release lever 11 of the friction clutch 10 to the diaphragm spring. The friction clutch 10 is released by pushing it to the left.

When the depressed clutch pedal is released, the input piston 43 is pushed back to the right with respect to the power piston 44 by the pressure in the pressure chamber 56 and the spring 61. This increases the communication area between the annular groove 44e of the power piston 44 and the annular groove 43f of the input piston 43, and the pressure in the working chamber 47 becomes effective. Therefore, the force of the diaphragm spring of the friction clutch 10, the return spring 5
2 and the force of the spring 63, each component of the transmission mechanism 70 and the hydraulic booster 40
Each component returns to the position shown in the figure. The valve mechanism 57 is opened by the right end of the rod 60 coming into contact with the piston 53 and by defining the rightward movement end of the pin 53 with respect to the output rod portion 44f, so that the valve mechanism 57 is opened. Pressure chamber 5
6 communicates with the drain chamber 50 again, and the piston 55 is in a state where it can be displaced to the right within the output rod portion 44f.

As a result, the clutch disk of the friction clutch 10 wears out, causing the release lever 11 to press the release bearing 75 to the right, and the rightward pressing force applied from the release bearing 75 to the piston 55 via the rod 71 is applied to the spring 63. When the sum of the force and the sliding resistance of the piston 55 is overcome, the piston 55 is slid to the right within the output rod portion 44f, and the release bearing 75 is thereby displaced.
This prevents the user from pressing the release lever 11 in the release direction with an involuntary force.

When the clutch release device 20 is installed in the vehicle, the air in the pressure chamber 56 is vented using the pump 48.
With the working fluid flowing through the hydraulic booster 40, the piston 55 is reciprocated within the output rod portion 44f. With this operation, the working fluid enters and exits the pressure chamber 56 via the open valve mechanism 57, and the air in the pressure chamber 56 is caught up in the flow of working fluid from the pressure chamber 56 to the drain chamber 50. and from the drain chamber 50 to the reservoir 51.

[Brief explanation of drawings]

The drawing is a sectional view of one embodiment of the present invention. DESCRIPTION OF SYMBOLS 10... Friction clutch, 11... Release lever, 20... Clutch release device, 30... Clutch pedal, 40... Open center type hydraulic booster, 43... Input piston, 44
...Power piston, 44f...Output rod, 5
0...Drain chamber, 55...Piston, 56...Pressure chamber, 57...Valve mechanism.

Claims (1)

[Claims] 1 A clutch release device for a vehicle that pushes a release lever of a friction clutch, which is normally engaged by the force of a spring, in the clutch release direction in response to depression of the clutch pedal, the clutch release device being controlled by the clutch pedal. In a vehicle clutch release device comprising a center type hydraulic booster and a transmission mechanism for mechanically transmitting the output of the hydraulic booster to the release lever, the clutch release device is slidable within the output rod of the power piston of the hydraulic booster. a piston fitted into the hydraulic booster side end of the transmission mechanism; a pressure chamber formed in the output rod portion by the piston; It includes a passage communicating with the drain chamber of the booster, and a normally open valve that shuts off the passage in conjunction with the operation of the input piston of the hydraulic booster, and this normally open valve and a part of the passage The input piston is provided within the tip of the input piston thrust into the pressure chamber, and is tensioned between the piston and the output rod within the pressure chamber so as not to bias the input piston. A clutch release device for a vehicle, in which a piston is urged outward from the output rod.