JPS6027853B2 - clutch master cylinder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a clutch master cylinder that is mounted on a vehicle or the like and is used to operate a clutch device.

A conventional clutch master cylinder includes a cylinder body in which a cylinder hole is formed, an actuation piston that is slidably inserted into the cylinder hole and defines a hydraulic pressure generation chamber, and a return spring that urges the actuation piston to a return position. a radially extending shaft-like member fixed to the cylinder body; a long groove formed in the center of the actuating piston with which the shaft-like member is aligned; a first passageway that communicates the long groove to the working fluid reservoir; A through hole extending to the end of the working piston, a second passage provided in the through hole for connecting the liquid pressure generating chamber and the liquid pressure generation chamber, and a second passage provided at the end of the working piston so as to be able to shut off the second passage. the valve, and a valve-opening member that connects the valve when the valve is not in operation and is disposed through the through hole.

However, in such a conventional master cylinder, the brake cylinder is used as is, so when the actuating piston moves from the operating position to the return position, when the brake pedal is pressed twice, pressure is generated in the hydraulic pressure generating chamber. There is a phenomenon in which hydraulic fluid flows from the reservoir into the hydraulic pressure generating chamber in response to the generated negative pressure.

In the clutch master cylinder, when such a phenomenon occurs, by depressing the clutch twice, the position of the clutch pedal that operates the clutch device changes each time the clutch is operated, and the desired clutch operation is based on a fixed position. Furthermore, if the hydraulic fluid is pumped out excessively by pressing the pedal twice, the operating piston of the clutch operating cylinder connected to the clutch master cylinder will stroke excessively, resulting in serious problems such as the operating piston popping out. A serious problem arises. The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a clutch master cylinder suitable for use in a clutch. established,
A second passage including the throttle passage is formed in the related valve member.

Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

FIG. 1 is a side sectional view of a clutch master cylinder according to an embodiment of the present invention, and FIG. 2 is an enlarged view of the main part of FIG. 1.

In the figure, the clutch master cylinder is indicated as a whole by 1, and this master cylinder includes a cylinder body 3 with a cylinder hole 2 bored into it, and an actuating piston 4 is inserted into the cylinder hole 2 so as to be super movable. , working piston 4
A hydraulic pressure generating chamber 5 is defined between the closed end of the cylinder hole 2 and the closed end of the cylinder hole 2 .

A return spring 6 is stretched between the operating piston 4 and the closed end of the cylinder hole 2, and urges the operating piston 4 to the return position.One end of this spring 6 is cup-shaped and has a hole 7. The pond end is in contact with the closed end of the cylinder hole 2 via the restriction valve 9. A connection hole 10 is provided on the left side of the restriction valve 9 to which a pipe connecting the hydraulic pressure generating chamber 5 to an operating cylinder (not shown) is attached.
The restriction valve 9 includes a plate 9 having a hole 9a and a through hole 9b.
c, and a rubber that prevents the hydraulic fluid from flowing into the hydraulic pressure generation chamber 5 through the hole 9a and prevents the hydraulic fluid from being sent out from the hydraulic pressure generation chamber 5 through other than the holes 9a and 9b. It has a sealing member 9d made of. The actuating piston 4 has flanges 11 and 12 formed on both ends thereof and has a reduced diameter at the center, forming a cylindrical replenishment chamber 13 between the inner wall of the cylinder hole 2 and communicating with this replenishment chamber 13. A slit-like long notch 14 is bored in the direction of the ball.

A ball-like part 15 of a bolt screwed onto the sill main body 3 passes through this innermost hole 14, and the actuating piston 4 is made movable along this shaft-like part 15. The head 16 of the actuating piston 4 located on the left side of the shaft-shaped portion 15 includes:
A through hole 17 is provided that extends in the axial direction continuously from the elongated hole 14, and one end of this through hole 17 is connected to the elongated notch 14, especially in the shaft-shaped portion 15.
The pond end is closed toward the inside of the spring receiver 8. A valve member 19 is placed in the spring receiver 8 so that the shaft portion 18 can slide into the through hole 17, and a valve spring 20' arranged between the spring receiver 8 and the valve member 19 is biased. It is possible to sit on a seat surface 21 formed on the end surface of the seat 16.

The valve part 19 has a main part 22 formed integrally with the shaft part 18 and a rubber sealing member 23 attached to the main part 22. The rod portion 18 of the valve member 19 is attached to the shaft portion 15, and a valve 2 formed from the valve member 19, a seat surface 21, etc.
The valve member 19 has an axial bow 25 and a radial hole in the ball portion 18, as shown in FIG. 26 is bored.

One end of the hole 25 is closed to the elongated hole 14, and the other end is closed to the hole 26 through a throttle 27 formed by reducing the inner diameter.
On the other hand, the hole 26 is provided at a position where it opens facing the gap between the sealing member 23 and the seat surface 21 when the valve 24 is engaged. These holes 25 and 26 and the throttle 27 form a passage 28 that communicates the elongated hole 14 and the hydraulic pressure generating chamber 5. Moreover, the gap between the shaft portion 18 and the through hole 17 is made extremely small, so that the movement of liquid between the inner periphery of the through hole 17 and the outer periphery of the shaft portion 18 is extremely minimized. Returning to FIG. 1, a lip seal type sealing member 3132 is attached to each of the actuating pistons 4, and a ring 33 is interposed in the cylinder hole 2 opening machine to the actuating piston 4. A stopper 34 is provided to define the return position of the replenishment chamber 13, and a hole 35 is provided in communication with the replenishment chamber 13.

A reservoir 3 is provided in the cylinder body 3 in communication with this hole 35.
6 is provided, and the reservoir 36 has a main body 38 that is iron-fitted to the cylindrical projection 37 of the cylinder main body 3, a cap body 39 attached to the main body 38, and a stopper 40. The operation of the above-mentioned master cylinder 1 will be explained below.

In a clutch device (not shown), when the clutch is in a fully engaged state, the master cylinder 1 is in an inactive state and each member is in the illustrated position.

That is, the actuating piston 4 is in a position where it is urged by the return spring 6 and engages with the stopper 34, and the shaft portion 18 abuts the rib portion 15 to open the valve 24, and the hydraulic pressure generating chamber 5 is opened. The hydraulic pressure inside the reservoir 36 is constant as it passes through the inside of the reservoir 36.

In this state, when the operator depresses the clutch pedal (not shown) and presses the actuating piston 4 via a push rod or the like, the actuating piston 4 moves against the return spring 6.
As a result, the ball portion 18 and the ball-shaped portion 15 are separated, and the valve 2
4 closes the valve.

As the valve 24 closes, pressure begins to be generated in the hydraulic pressure generating chamber 5, and the pressure liquid is first sent out through the through hole 9b of the restriction valve 9, and when the pressure further increases, the pressure starts to be generated in the hydraulic pressure generating chamber 5. The liquid is also sent through the clutch operating cylinder and the clutch is disengaged. Then, when the operator completes the necessary operations while the clutch is disengaged, the operator gradually releases the depression of the clutch pedal until it reaches the inactive position, in other words, the operator removes the foot from the clutch pedal.

At this time, the actuating piston 4 gradually moves to the right and finally returns to the position where it engages with the stopper 34, and the shaft portion 18 comes into contact with the shaft-shaped portion 15, and the valve 24 is fully opened. In response to these operations, the clutch changes from a disengaged state to a half-clutch state to a fully engaged state. In this series of operations, in the above embodiment, since the throttle passage 30 is provided, even if negative pressure is generated in the hydraulic pressure generation chamber 5 during the return operation,
The amount of hydraulic fluid flowing into the hydraulic pressure generating chamber 5 from the recess 14 is small, and the operating piston 4 moves slowly to the left in accordance with the amount of hydraulic fluid returning from the hole 9b of the restriction valve 9.

As a result, even if the clutch pedal is depressed again during the return operation, or in other words, even if the clutch pedal is depressed twice, the amount of excess hydraulic fluid flowing into the piping system including the hydraulic pressure generation chamber 5 is small.
The amount of depression of the clutch pedal when the clutch is completely disengaged hardly changes even when the clutch pedal is depressed twice, and also hardly changes when trying to obtain a half-clutch state. After all, the clutch device can be operated with a constant operation. Further, since excessive hydraulic fluid is not sent to the clutch operating cylinder, the piston of the tartarage verating cylinder does not fly out, improving reliability and safety.

Furthermore, the throttle 27 is provided in a passage 28 that communicates the elongated hole 14 and the hydraulic pressure generating chamber 5, and this passage 28
It has excellent compatibility with conventional products.
Further, the passage 28 is formed from the hole 25 and the hole 26, and the hole 25
Since the closed end of the hole 26 is reduced to a small diameter portion, and this small diameter portion is used as the aperture 27, the means for providing the aperture 27 is simple, and there are few parts to be machined with high precision, achieving the desired purpose. The aperture 27 can be easily and accurately formed by drilling the diameter. Furthermore, since the restriction valve 9 is used, the air in the master cylinder 1 can be quickly vented even though the throttle 27 is provided.
In addition, in the above embodiment, an example was shown in which the aperture 27 was provided at one end of the hole 25, but the present invention is not limited to this example and can be modified.

That is, for example, referring to FIG. 2, there are examples in which a separate member on which the aperture 27 is formed is competitively fixed in the hole 25 or the hole 26, or the aperture 27 is not provided in the hole 25 and the diameter of the hole 26 is fixed. In the latter case, the hole 26 does not penetrate in the radial direction, but the hole 26
5 and the hydraulic pressure generation chamber 5 are connected through one closed opening.In short, the passage 2 provided in the shaft portion 18
8 should be provided with an aperture. In addition, the degree of such restriction is preferable as the passage area of the restriction is smaller.
Considering speed and reliability during air purge work, the amount that changes by pressing twice is about 2 times in terms of the piston stroke of the operating cylinder (displacement length at one end of the with-row lever of the clutch device). It is sufficient to have a restricting effect to the extent that it can be suppressed, and it may be set as appropriate depending on the type and size of the operating cylinder, clutch master cylinder, etc.

Furthermore, when using the restriction valve 9, it is preferable to set the entrance area of the hole gb to an area that provides a large throttling effect, considering the speed of the air purge operation. In order to ensure the effect of the above-mentioned throttling that prevents fluid from flowing into the hydraulic pressure generation chamber, the closed area of the hole 9b is preferably made large to some extent, and this depends on the degree of the throttling described above. Set as appropriate.

As is clear from the above description, according to the present invention, it is possible to obtain a clutch master cylinder suitable for use in a clutch.

[Brief explanation of the drawing]

FIG. 1 is a sectional side view of a clutch master cylinder according to an embodiment of the present invention, and FIG. 2 is an enlarged view of the main part of FIG. 1...Clutch master cylinder, 18...shaft portion, 27...throttle, 28...passage. Figure *O2 figure

Claims (1)

[Claims] 1. A cylinder body having a cylinder hole formed therein, an actuating piston slidably inserted into the cylinder hole to define a hydraulic pressure generation chamber, and a return spring urging the actuating piston to a return position;
a radially extending shaft member fixed to the cylinder body;
a long groove provided in the center of the actuating piston into which the shaft-shaped member fits; a first passage communicating the elongated groove with a hydraulic fluid reservoir; a through hole extending from the elongated groove to an end of the actuating piston; a second passage provided in the through hole and communicating between the long groove and the hydraulic pressure generating chamber; a valve provided at the end of the actuating piston so as to be able to shut off the second passage; and a valve that is opened when not in operation. In the clutch master cylinder equipped with a valve opening member disposed through a through hole, a throttle passage is provided in the second passage, and a second passage including the throttle passage is formed in the valve opening member. Consists of clutch master cylinder.