JPH0544587Y2 - - Google Patents

Description

[Detailed description of the invention] A. Purpose of the invention (1) Industrial application field The present invention relates to a negative pressure booster used for operating a clutch master cylinder, and in particular, relates to a booster shell and a front part inside this booster shell. a booster piston that is movable back and forth and partitioned into a negative pressure chamber at the front and a working chamber at the rear; a return spring that biases the booster piston toward the working chamber; an input rod connected to the clutch pedal; a control valve that switches the working chamber to the atmosphere and the negative pressure chamber according to the movement of the input rod toward and away from the booster piston;
An output rod connected to the piston of the clutch master cylinder in front of the booster piston, and a reaction rod that connects the booster piston and input rod to the output rod and distributes the operating reaction force of the output rod to the booster piston and input rod at a fixed ratio. The present invention relates to an improvement in a force mechanism, in which the output piston of the reaction force mechanism is slidably fitted into a cylinder hole having a diameter larger than the output rod, which is opened in the front surface of the booster piston.

(2) Prior art In general, while the clutch master cylinder is operating, engine vibrations are transmitted to the operating side, that is, the clutch pedal side, via the clutch master cylinder's hydraulic system. As a vibration means, one in which a damper member is interposed at the connection between the clutch pedal and the push rod of the master cylinder is known (see, for example, Japanese Utility Model Publication No. 61-2836).

(3) Problems to be solved by the invention However, when the clutch master cylinder is operated by a negative pressure booster, the connection between the clutch pedal and the input rod of the negative pressure booster is Even if a damper member is interposed in the connecting portion, a satisfactory vibration-proofing effect cannot be obtained. This is because when engine vibrations are transmitted to the output rod of the negative pressure booster, they are amplified by the reaction force mechanism and the booster piston.

The present invention was developed in view of the above circumstances, and is a clutch master cylinder that effectively absorbs engine vibrations from the hydraulic system of the clutch master cylinder and blocks transmission of vibrations to the clutch pedal side. The purpose is to provide a negative pressure booster for operation.

B. Structure of the device (1) Means for solving the problem In order to achieve the above object, the present invention provides a structure in which a booster piston is provided in front of the booster piston between the output rod and the output piston of the reaction force mechanism. It is characterized by interposing a damper member housed in a cylinder hole into which the cylinder is slidably fitted.

(2) Effect When the clutch master cylinder is in operation, when engine vibration is transmitted from the master cylinder piston to the output rod of the negative pressure booster, it is absorbed by the damper member between the output rod and the reaction force mechanism. The vibrations are not amplified by the reaction force mechanism and the booster piston.

In particular, the damper member is housed in a cylinder hole that is larger in diameter than the output rod that is formed on the front surface of the booster piston in order to slide the output piston of the reaction mechanism, so it is possible to use a relatively large-diameter damper member. The surface pressure applied to this is also reduced as much as possible, and since this damper member is located inside the booster shell and the master cylinder's hydraulic pressure does not directly act on the outer periphery, it is relatively easy to elastically deform, reducing the damper effect. It can be fully demonstrated.

(3) Examples Examples of the present invention will be described below with reference to the drawings.

First, starting with the first embodiment of the present invention, in FIG. 1, V is a negative pressure booster operated by a clutch pedal P of an automobile, and a booster shell 1 in front of which is operated by the booster V. Clutch master cylinder M is installed. Further, the output port of the clutch master cylinder M is connected through a hydraulic conduit L to the input port of a clutch slave cylinder S which controls a clutch of a power system (not shown). The clutch slave cylinder S is adapted to disconnect the clutch when receiving hydraulic pressure from the clutch master cylinder M.

The booster shell 1 consists of a pair of front and rear shell halves 1a and 1b whose opposite ends are connected to each other. Inside this booster shell 1, a booster piston 2 is housed in the booster shell 1 so as to be able to reciprocate back and forth, and a diaphragm 3 is attached to the rear surface of the booster shell 1 and sandwiched between the front and rear shell halves 1a and 1b. The booster piston 2 is divided into a negative pressure chamber A and a rear working chamber B, and a return spring 4 that biases the booster piston 2 in the backward direction is housed in the negative pressure chamber A.

The booster piston 2 has a boss 5 protruding forward from its center and a valve cylinder 6 protruding rearward.
The valve cylinder 6 is a rear extension cylinder 7 of the rear half shell 1b.
is slidably supported via a bush 8 and a seal member 9. The rear open end of the valve cylinder 6 serves as an atmosphere inlet 10.

The negative pressure chamber A is connected to a negative pressure source (not shown) (for example, inside an intake manifold of an internal combustion engine) through a negative pressure introduction pipe 11, and is connected to a first valve seat (described later) through a first through hole ₁₂₁ . 16 It communicates with the inside of the valve cylinder 6 rearward from ₁ . Further, the working chamber B is communicated with the inside of the valve cylinder 6 in front of the first valve seat 16 ₁ , which will be described later, via the second passage hole 12 ₂ .

a control valve 13 that controls communication/blocking between the first and second through holes 12 ₁ , 12 ₂ and the atmosphere inlet 10;
An input rod 14 for operating the input rod 14 is disposed within the valve cylinder 6 as follows.

That is, a valve piston 15 , which is swingably connected to the front end of the input rod 14 , is slidably connected to the front portion of the valve cylinder 6 . Further, a valve piston 1 is provided on the inner circumferential wall of the valve cylinder 6.
An annular first valve seat 16 behind the sliding portion of No. 5
A _second valve seat 16 ₂ is formed at the rear end of the valve piston 15 and surrounded by a second valve seat 16 2 .
A valve body 17 that cooperates with 6 ₁ and 16 ₂ is attached to the valve barrel 6 .

The valve body 17 is made of rubber and has a cylindrical shape with both front and rear ends open.
is held in close contact with the inner peripheral surface of the valve cylinder 6 by a holding cylinder 18 fitted to the inner peripheral surface of the valve cylinder 6, and the hollow portion of the valve body 17 is communicated with the atmosphere inlet 10.

The valve body 17 includes a thin flexible portion 17b bent radially inward from the base end portion 17a, and a thick valve portion 17c continuous to the front end of the flexible portion 17b. Due to this deformation, the valve portion 17c can be seated on and separated from the first and second valve seats 16 ₁ and 16 ₂ .

An annular reinforcing plate 19 is embedded in the valve portion 17c,
A valve spring 20 is compressed between this and the input rod 14 and urges the valve portion 17c toward both valve seats 16 ₁ and 16 ₂ .

As described above, the control valve 13 is constructed, and the clutch pedal P is connected to the rear end of the input rod 14 that extends rearward from the air inlet 10.

Between the input rod 14 and the holding cylinder 18, the input rod 14
A return spring 21 is provided that urges the retracting direction.

A projecting shaft 22 is provided on the front end surface of the valve piston 15 and extends through the partition wall 2a between the boss 5 of the booster piston 2 and the valve cylinder 6.
A stopper ring 23 facing the front surface of a is locked. When the stopper ring 23 comes into contact with the partition wall 2a, the backward limit of the input rod 14 relative to the booster piston 2 is restricted.

The boss 5 of the booster piston 2 has the partition wall 2
A small-diameter hole 24 adjacent to a, and a large-diameter hole 25 as a cylinder hole that is connected to the front end of the small-diameter hole 24 and opens on the front surface of the boss 5. A contactable reaction piston 26 is slid into the large diameter hole 25, and an elastic piston 27 and an output piston 28 are slid into the large diameter hole 25 in order from the back thereof. These pistons 26, 27, and 28 constitute a reaction force mechanism R.

The output piston 28 includes an output rod 31 whose front end is connected to the piston 30 of the clutch master cylinder M.
are connected via a damper member 32.

That is, the output piston 28 has its open end connected to the negative pressure chamber A.
The damper member 32 and the connecting flange 31a formed at the rear end of the output rod 31 are inserted into the cylinder, and the output piston 28
a plurality of retaining pieces 33, which are caulked inwardly on the front end wall of the
33... prevents the connecting flange 31a from being pulled out from the output piston 31.

The damper member 32 is made of rubber and has a cylindrical shape, and is preloaded in the axial direction between the output piston 28 and the output rod 31, and has a gap between it and the inner peripheral surface of the output piston 28 so that it can be compressively deformed. A gap 34 is formed. The damper member 32 has a through hole 35 in the center, and positioning protrusions 36 and 37 protruding from the opposing surfaces of the output piston 28 and the connecting flange 31a are fitted into both ends of the through hole 35, respectively. Thus, the output piston 28, damper member 32, and connection flange 31a are positioned coaxially.

In the figure, numeral 38 denotes an air filter attached to the air inlet 38, which has flexibility so as not to hinder the movement of the input rod 14.

Next, the operation of this embodiment will be explained.

When the negative pressure booster V is inactive, the input rod 14 is moved by the force of the return spring 21, as shown in FIG.
The stopper ring 23 of the valve piston 15 is held at the retracted limit where it abuts against the partition wall 2a. In this case, the second valve seat ₁₆₂ of the valve piston 15 is connected to the valve portion 17c of the valve body 17.
At the same time, the valve portion 17c is engaged with the valve spring 20.
The valve cylinder 6 is separated from the first valve seat 16 ₁ against the force of the valve cylinder 6 . Therefore, the working chamber B is cut off from communicating with the atmosphere inlet 10, and the first through hole 12 ₁ and the first
Between the valve seat 16 ₁ and the valve part 17c, the second through hole 12 ₂
It is communicated with negative pressure chamber A through. As a result, the atmospheric pressures in the negative pressure chamber A and the working chamber B are balanced, so that the booster piston 2 is held at its retracting limit by the force of the return spring 4, where it abuts against the partition wall of the booster shell 1 via the diaphragm 3.

Now, if you depress the clutch pedal P and move the input rod 14 and valve piston 15 forward in order to shut off the clutch in the power system of the automobile, initially the valve cylinder 6
As the valve piston 15 advances, the valve body 17 is seated on the first valve seat 161 by the force of the valve spring 20, and the second valve seat ₁₆₂ is seated on the valve body 1 _.
Leave 7c. As a result, the working chamber B is disconnected from the negative pressure chamber A and communicated with the atmosphere inlet 10, so that the atmosphere flows from the atmosphere inlet 10 to the space between the second valve seat ₁₆₂ and the valve portion 17c. 〓, and second through hole 1
₂ into the working chamber B, and the working chamber B has a higher pressure than the negative pressure chamber A. Therefore, the booster piston 2 obtains a large forward force based on the pressure difference between the two chambers A and B, and moves forward against the force of the return spring 4.
The forward force of the booster piston 2 is transmitted to the output rod 31 via the reaction force mechanism R and the damper member 32,
Since the piston 30 of the clutch master cylinder M is driven forward, the clutch slave cylinder S is actuated by the output hydraulic pressure, and a clutch (not shown) can be brought into a disconnected state.

During such a closing operation of the clutch, the protruding shaft 22 of the valve piston 15 advances together with the input rod 14 and comes into contact with the elastic piston 27 via the reaction piston 26. It bulges and deforms toward the small diameter hole 24 side due to the reaction force of the operation.
Since a part of the reaction force is applied to the reaction piston 26, the force is fed back to the clutch pedal P side via the valve piston 15 and the input rod 14, so that the operator can control the clutch master cylinder M of the output rod 31. It is possible to know the magnitude of the driving force for.

In addition, when the clutch is in the disconnected state, engine vibrations are transmitted from the clutch slave cylinder S to the hydraulic conduit L.
Pass the pressure oil inside to the clutch master cylinder M.
Furthermore, the vibration is transmitted to the output rod 31 via the piston 30, but since the vibration is absorbed by the damper member 32 interposed between the output rod 31 and the output piston 28, it may be amplified by the negative pressure booster V. Therefore, vibration transmission to the input rod 14 can be effectively blocked.

FIG. 2 shows a second embodiment of the present invention, in which a connecting flange 31a of an output rod 31 is connected to a damper member 32.
The structure is the same as that of the previous embodiment, except that it is held by the same reference numerals as those of the previous embodiment.

According to this embodiment, the lateral vibration of the output rod 31 can also be reliably absorbed by the damper member 32.

C. Effect of the invention As described above, according to the invention, since the damper member is interposed between the output rod and the output piston of the reaction force mechanism, when the clutch master cylinder is operated, negative pressure is generated through the hydraulic system. The engine vibrations transmitted to the booster can be effectively absorbed in the negative pressure booster on the side near the reaction mechanism, and their amplification can also be prevented, thereby effectively reducing the transmission of vibrations to the clutch pedal side. can be blocked.

In particular, since the damper member is housed in a cylinder hole that has a larger diameter than the output rod that is formed on the front surface of the booster piston in order to slidably fit the output piston, a relatively large-diameter damper member is used. This makes it possible to reduce the surface pressure applied thereto as much as possible, thereby contributing to improving the durability of the damper member. Moreover, since the damper member is located within the booster shell and the hydraulic pressure of the master cylinder does not directly act on the outer periphery, it is relatively easy to elastically deform and a sufficient damper effect can be obtained.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention; FIG. 1 is a longitudinal sectional side view of the first embodiment of the invention, and FIG. 2 is a longitudinal sectional side view of main parts of the second embodiment of the invention. A...Negative pressure chamber, B...Working chamber, L...Hydraulic conduit, M...Clutch master cylinder, P...Clutch pedal, S...Clutch slave cylinder,
R...Reaction force mechanism, V...Negative pressure booster, 1...Booster shell, 2...Booster piston, 4...
Return spring, 10...Air inlet, 13...Control valve, 14...Input rod, 25...Large diameter hole as cylinder hole, 31...Output rod, 32...Damper member.

Claims (1)

[Scope of utility model registration request] A booster shell 1, a booster piston 2 that can move back and forth and divides the interior of the booster shell 1 into a negative pressure chamber A at the front and a working chamber B at the rear, and a booster piston 2 that urges the booster piston 2 toward the working chamber B. Return spring 4
, an input rod 14 which is disposed at the rear of the booster piston 2 so as to be able to move forward and backward relative thereto and is connected to the clutch pedal P; and an input rod 14 that is connected to the clutch pedal P so as to be able to move forward and backward relative to the booster piston 2; a control valve 13 for switching communication to chamber A;
An output rod 3 connected to a piston 30 of a clutch master cylinder M in front of the booster piston 2
1, and a reaction force mechanism R that connects the booster piston 2 and the input rod 14 to the output rod 31 and distributes the operational reaction force of the output rod 31 to the booster piston 2 and the input rod 14 at a constant ratio. The output piston 28 of the reaction force mechanism R is located in a cylinder hole 2 with a larger diameter than the output rod 31, which is opened on the front surface of the booster piston 2.
5, the negative pressure booster for actuating the clutch master cylinder includes a damper housed in the cylinder hole 25 between the output rod 31 and the output piston 28 of the reaction force mechanism R. A negative pressure booster for operating a clutch master cylinder, characterized in that a member 32 is inserted.