JP2661695B2 - Hydraulic drive actuator - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulically driven operating device of an automobile, and more particularly to a hydraulic brake device and a device for operating a hydraulic clutch.

(Problems of the prior art) By the pedal operation that can operate the operating piston,
Auxiliary pressure application cylinder that supplies pressure medium to the driven cylinder that is acting on the brake chamber and clutch release yoke, a control piston coaxially arranged with the working piston, and a constant pressure vacuum chamber in the booster housing. A vacuum booster having a pressure working piston and a movable wall cooperating with the working piston;
And a control valve device formed of a valve seat and a poppet valve acting together with the two valve seats, the control valve device being controllable by a control piston, wherein the movable wall is moved by a pressure difference acting on the movable wall. , Transmitted on the working piston, the movement of the working piston and the control piston being caused in opposite directions in the operating state of the vacuum booster.

A similar hydraulically driven actuator is known from the applicant's prior application (West German Patent 36 08 699). The gist of the invention described therein describes a device that moves a vacuum valve seat to its end approaching a poppet valve and slides within an actuation piston, and an actuation piston movably guided to a movable wall. Have been. This arrangement is preferably such that the movements of the working piston and the control piston are moved in opposite directions in the operation of the vacuum booster, and a reaction force proportional to the hydraulic output press is exerted around the control piston between the control piston and the movable wall. Are selected so as to be generated by elastic reaction elements arranged concentrically to each other.

However, it has to be recognized that this is a small advantage of the known actuators, because of the complex structure described above, which necessarily requires a large amount of actuation forces and costs. Another disadvantage is that most of the moving parts need to be sealed with respect to each other, which creates undesirable friction in the device. Moreover, it becomes somewhat difficult to control the desired rate of change of the functional properties. Another disadvantage is that the release action of the known actuators is relatively slow, which is unsuitable especially when used as a clutch actuator.

SUMMARY OF THE INVENTION AND EFFECTS It is therefore an object of the present invention to provide a hydraulic drive actuator similar to that described above. In the present invention, the above-mentioned problems are largely avoided, and the configuration can be simply configured, while maintaining a high degree of reliability of operation.

The aim is that the booster housing is always in communication with the atmosphere and is integrated into a chamber which can be connected to the working chamber, and in its non-operating position the poppet valve has a sealing surface on the second valve formed on the control piston. In that it is biased in the direction of operation of the control piston, and that the working piston is rigidly connected to the movable wall together with the control valve housed in the booster housing.
This is accomplished according to the invention.

Thus, in many improvements in the release operation of the vacuum output base, a hydraulic drive for a motor vehicle is achieved. Thus, after the response of the vacuum power booster, the contact between the control piston and the poppet valve will not be maintained and there will be no resultant force resulting from the pressure differential acting on the poppet valve. The result is a more comfortable pedal spacing for the driver. In addition, the working piston is moved through the movable wall through its delayed position when the vacuum output booster is released, thus allowing a quicker reduction in the pressure exerted in the auxiliary pressure application cylinder. .

An advantageous improvement of the subject matter of the present invention provides a chamber in the booster housing that is always in communication with the atmosphere, the chamber being separated by bellows and clamped to the housing half and the movable wall.

While the invention is of particular importance for operating hydraulic clutches with low pedal effort, on the other hand it is necessary to introduce as high a pedal rearrangement effort as possible at the same time as the actuation effort is reduced. This need depends on the stroke covered by the volume of pressure medium provided for actuation and activation of the vacuum booster, by the control of the hydraulic press to generate in the auxiliary pressure application cylinder, as well as by the remaining operating force do it,
It is satisfied by the gist of the invention, which is of an excellent type in that it is achieved exclusively by reaching the working point of the vacuum booster.

When using the subject matter of the present invention for operation of a hydraulic brake device, the present invention is hermetically guided within a movable wall to transmit a reaction force proportional to a hydraulic output press on a brake pedal. It has a control piston with a shaft extension and with a plate secured to it and a vacuum chamber formed in a movable wall with a diagram approaching said plate and sealingly partitioned. This measure serves to correct the braking force when the brake pedal is depressed. Still further, changes in the surface of the plate allow the transmission ratio (slope of the characteristic curve) of the device to be changed in a convenient and simple manner.

In particular, the simple form of the object actuation mechanism of the present invention results from the fact that the diaphragm is formed entirely by the rotating diaphragm of the movable wall.

Other details and advantages of the dish of the actuator of the invention will be understood from the description and subclaims of two embodiments of the invention, which are described in more detail below with reference to the attached drawings.

(Example) In FIG. 1, reference numeral 100 indicates a clutch pedal. The lever 101 of the clutch pedal 100 is bolted
It is pivotally supported by 102. Also, lever 1
01 is connected by a piston rod 111 to a piston 104 arranged in the drive cylinder 103. The fluid pressure driven booster device 110 is an essential element of the present invention, and includes a pneumatic vacuum booster 2 and an auxiliary pressure adding cylinder 1. The booster device 110 is connected to the drive cylinder 103 via a hydraulic path 105 on the one hand, and to the driven cylinder 107 via a hydraulic path 106 on the other hand. The piston 108 of the driven cylinder 107 is connected to a release fork of a clutch (not shown) by a piston rod 109.

The structure of the booster device 110 schematically shown in FIG.
This is explained in more detail by the first embodiment shown in FIG. As already described, the booster device 11
0 is constituted by a vacuum cylinder and an auxiliary pressure applying cylinder 1. The auxiliary addition cylinder 1 is provided with a flange, and the auxiliary pressure addition cylinder is fixed to the booster housing 21 by a fixing bolt 44 and a lock nut 43. Here, the booster housing 21 includes two booster housing halves 21a and 21b.

The working piston 4 is slidably guided in the cylindrical hole 10 of the auxiliary pressure applying cylinder 1, and the right end of the working piston 4 shown in the drawing projects inside the booster housing 21. On the side remote from the vacuum booster 2,
The end of the working piston 4 has an annular surface on which one end of a compression spring 13 is supported. The compression spring 13 urges the working piston 4 in the inoperative position in the direction of the vacuum booster 2. The working piston 4 includes a central valve. The central valve 8 includes a valve member 35, a compression spring 34 for urging the valve member 35 in a closing direction, and a holder 33. A valve member 35 formed on the working piston 4 and cooperating with a valve seat 36 is fixed to a pin 32, which extends through a shaft hole 37 of the working piston. The purpose of the pin 32 will be described in more detail in connection with its function in the clutch actuator. The auxiliary pressure applying cylinder 1 has a screw hole 14 at the left end thereof as seen in the drawing, which is used for connecting the hydraulic path shown in FIG.

The end wall of the cylindrical hole 10 and the working piston 4 define a pressure chamber 49, and the working piston 4 is sealed with respect to the cylindrical hole 10 by sealing means 38 disposed on the surface. The shaft hole 37 containing the pin 32 is connected to another shaft hole 15, which extends to the center of the working piston 4. The axial hole 15 is connected to the annular chamber 11 of the auxiliary pressure applying cylinder 1 via a radial hole 16, and the radial hole 16 houses a retaining ring 18 via a screw hole 17. The retaining ring 18 is connected to the driven cylinder 103 via the hydraulic path 105 shown in FIG.

The annular chamber 11 is slidable on the working piston 4 and cooperates with a cross pin 12 for operating the central valve 8.

At the right end of the auxiliary pressure-applying cylinder 1 shown in the drawing, the annular collar of the working piston 4 has a bush 48 on which a retaining ring 41 pressed against a retaining shaft 41 is fixed in place by a bush 48. Is positioned at a predetermined position in a large-diameter hole portion 55 of the cylindrical hole 10 by a holding ring 59, and is sealed by the O-ring 25 from the large-diameter hole 55. At the same time, the bushing 48 serves to guide the working piston 4 in the axial direction and is sealed to the working piston 4 via the sealing sleeve 31. The seal sleeve 31 is disposed in a recess of the bush 48.

The hole 15 of the operating piston 4 is connected to the large diameter portion 19,
In the large diameter portion 19, the control piston 3 is slidably arranged coaxially and is sealed by a grooved ring 20. In this configuration, the control piston 3 forms a part of a control valve device, and the purpose of the adjustment valve device will be described below.

In the vacuum booster 2 cooperating with the auxiliary pressure applying cylinder 1, the booster housing 21 is divided into a vacuum chamber 23 and a working chamber 24 by a movable wall 22 movable in the axial direction. The axially movable wall 22 includes a diaphragm plate 26.
And a flexible rolling diaphragm. Sealed in plate 26 and sealing the area between the outer periphery of diagram plate 26 and booster housing 21. The vacuum chamber 23 is connected via a check valve (not shown) to a suitable negative pressure source, for example, an intake pipe of an internal combustion engine. In this configuration, the diaphragm plate 26 is formed integrally with the control valve housing 6 disposed in the booster housing 21, and includes the control valve housing 6, the control piston 3, and the valve seat 28 disposed radially inward. , Valve seat arranged radially outside
29 and the poppet valve 30 constitute a control valve device of the vacuum booster 2.

In the inoperative position of the vacuum booster 2, the poppet valve 30
Is seated radially inwardly on the valve seat 28, and the poppet valve 30 is biased in the direction of the valve seat 28 by a compression spring 40. On the other hand, the other end of the compression spring 40 is supported by a pressure member, and the pressure member 5 is inserted into the control valve housing 6. The pressure member 5 provides a firm connection between the movable wall 22 and the working piston 4.

In the booster housing 21, an intermediate chamber 7 that can be connected to the working chamber 24 is provided.
It is separated by a bellows 9 clamped between the booster housing half 21a on the left side in FIG.
The shaft chamber 7 is normally connected to the outside air through an atmosphere suction passage 42, and similarly, the chamber 7 is connected to an annular chamber defined by the poppet valve 30 via an axial passage 50 in the pressure member 5. Have been.

At the end of the control valve housing 6 on the side close to the working chamber 24, a cylindrical recess 52 is provided which, on the one hand, passes through several radial holes 51 and into the vacuum chamber 23.
And, on the other hand, to the working chamber 24 via an air passage 46. This passage 46 is formed in an end wall 56 that closes the control valve housing 6. Simultaneous depression 52
A compression spring 54 is housed therein.
On the one hand is supported by the end wall 56 and on the other hand is located in the recess 53 of the control piston 3
It is supported by.

Finally, FIG. 3 shows a partial cross-sectional view of another embodiment of a vacuum booster which can be used in the operating device of the present invention for operating the hydraulic brake system. All parts corresponding to have the same reference numbers. In this embodiment, the control piston 3
Is provided with an axial extension 45, and this axial extension 45
Has a plate 47 fixed thereto. The plate 47 defines a vacuum chamber 58 together with the diaphragm 39 in contact with the plate 47. The vacuum chamber 58 is formed in the diaphragm plate 26, and is connected to the vacuum chamber 23 via a vacuum path 60. The inside of the control valve housing 6 is a vacuum chamber
In contrast to 58, it is sealed by an O-ring 57 and is connected to the working chamber 24 via a radial path 61. As a result, the plate 47 can receive the pressure left applied to the movable wall 22, thereby forming a transmission mechanism that receives hydraulic feedback.

The functional modes of the hydraulic actuator according to the invention will be described below with particular reference to FIGS. 1, 2 and 4. According to the present invention, the inoperative position of the actuator is the position shown in FIG.

As already described, the vacuum chamber of the vacuum booster 2
23 is connected to a suitable vacuum source. In the non-operating position shown, the negative pressure generated by this vacuum source is applied to the radial holes 51 of the diaphragm plate, the valve seat 2 in the closed state.
9, recess 52 and air passage 4 in control valve housing 6
Via 6, it is transmitted into the working chamber 24, whereby a negative pressure is generated in the vacuum chamber 23 and the working chamber 24 in the non-working position.

When the operating device is operated by pushing the clutch pedal 100 (FIG. 1), a hydraulic pressure is generated in the drive cylinder 103, and this pressure is applied to the path connected to the screw hole 17.
105, through the annular chamber 11 and the central valve 8 in the open state,
It is transmitted in the direction of the driven cylinder 107. When the oil pressure further increases, the control piston 3 in FIG. 2 is moved to the right against the urging force of the compression spring 54. This allows the poppet valve
The first 30 sits on the radially outer valve seat 29, so that the connection between the vacuum chamber 23 and the working chamber 24 is cut off. Furthermore, the increase in pressure in the annular chamber 11 moves the control piston 3 further to the right. Thereafter, the valve seat 28 formed in the control piston 3 is lifted against the poppet valve 30 against the action of the spring force of the compression spring 54, and as a result, the working chamber 24 becomes the air passage 46, the intermediate chamber 7 Then, the air passes through the suction air passage 42 and communicates with the atmosphere. (In FIG. 4, the operating point A of the vacuum booster) The working piston 4 is moved on the movable wall 22 in accordance with the working force guided through the hydraulic path 105 and the pressure difference between the vacuum and the working chambers 23 and 24. Is moved to the left by the auxiliary force acting on

As a result, the central valve 8 is closed under the force of the compression spring 34, and the annular chamber 11 is separated from the pressure chamber 49. Here, a boost pressure is generated in the pressure chamber 49 of the auxiliary pressure applying cylinder 1, and the boost pressure is
Of the piston 108. The movement of the working piston 4 to the left increases the volume of the annular chamber 11, whereby the pressure in the annular chamber 11 is reduced. This also reduces the force applied to the control piston 3, whereby the valve seat 28 of the adjusting piston 3 is closed under the force of the compression spring 54.

This stops the supply of atmospheric pressure into the working chamber 24,
This prevents a pressure increase in the auxiliary pressure application cylinder 1 and keeps the vacuum booster 2 in its operating position.

The introduction of the atmosphere into the working chamber 24 thereafter is continued until the inlet pressure corresponding to the working point A (FIG. 4) is reached again.
This is achieved by supplying hydraulic pressure via the hydraulic pressure path 105. .

In this way, the actuating device is controllable by means of the adjusted inlet chamber volume (pedal stroke), while the driving capacity of the actuating device is increased at the moment when the working chamber 24 reaches atmospheric pressure (FIG. 4). It will be used up at the maximum pressure increase point B).

As soon as the pressure in the annular chamber 11 has reached a value corresponding to the point C during the release operation (reduction of the operating force), the control piston 3 is moved to the left by the action of the compression spring 54. As a result, the poppet valve 30 sitting on the valve seat 29 is lifted from the valve seat 29k. Thereby, the pressure in the annular chamber 11 is further reduced by the return of the pedal 100 corresponding to the distance CD (FIG. 4). At point D, the central valve 8 is opened (the working piston 4 moves and abuts the retaining ring 41), so that the subsequent pressure reduction takes place in a one-to-one ratio.

As is apparent from the description of the hydraulically controlled clutch actuating device of the present invention, the control is performed depending on the distance covered by the clutch pedal. The dependence between the outlet pressure of the actuator and its inlet pressure can be changed independently by controlling the spring force of the compression spring 54 which biases the control piston 3.

[Brief description of the drawings]

FIG. 1 is a schematic view of an operating device for operating a hydraulic clutch having a vacuum booster driven by hydraulic pressure, FIG. 2 is an axial sectional view showing one embodiment of a vacuum booster according to the present invention, FIG. The figure is a partial sectional view of another vacuum booster, and FIG. 4 is a diagram showing the dependence of the outlet pressure on the basis of the inlet pressure of the actuator, which is proportional to the operating force. 1 ... cylinder for applying auxiliary pressure, 2 ... vacuum booster, 3 ...
... control piston, 4 ... working piston, 5 ... pressure member, 6 ... control valve housing, 7 ... intermediate chamber, 15, 37 ...
... bearing holes, 21 ... booster housing, 22 ... movable wall, 24 ... working chamber, 28 ... valve seat, 30 ... poppet valve.

Claims (9)

(57) [Claims] An auxiliary pressure applying cylinder for supplying a pressure medium to a driven cylinder operated by a brake member and / or a clutch release yoke by a working piston operated by a pedal, and is arranged coaxially with the working piston. A vacuum booster comprising: a control piston; a working piston in which a constant pressure inside the vacuum chamber is changed in a booster housing; and a movable wall cooperating with the working piston; and first and second valve seats; A control valve device formed by these valve seats and a cooperating poppet valve and controllable by a control piston, wherein the movement of the movable wall caused by the pressure difference acting on the movable wall is transmitted onto the working piston. The movement of the actuating piston and the control piston occurs in the opposite direction when the vacuum booster is actuated. An intermediate chamber is provided in the housing, and the intermediate chamber is always in communication with the atmosphere and can be connected to the working chamber. When not operating, the poppet valve is connected to the second piston formed on the control piston. And is urged in the operating direction of the control piston,
A hydraulic drive actuator, wherein the actuation piston is rigidly connected to the movable wall and the control valve housing is arranged in the booster housing. 2. An intermediate chamber in the booster housing, which is always in communication with the atmosphere, is defined by a bellows clamped between the movable wall and the booster housing half. The hydraulically actuated operating device according to claim 1. 3. A hydraulically actuated operating device according to claim 1, wherein the rigid connection between the working piston and the movable wall is provided by a pressure member which prevents a clearance in the movable wall. 4. When the vacuum booster is in operation, the pressure member:
An intermediate chamber in the booster housing communicates with the working chamber via several air passages extending axially into the movable wall, comprising at least one path extending axially on the operation of the vacuum booster. The hydraulically actuated operating device according to claim 3, characterized in that: 5. A hydraulically actuated operating device according to claim 3, wherein at its end moving away from the sealing surface, the poppet valve is clamped between the movable wall and the pressure member. . 6. The control of the hydraulic pressure energized in the auxiliary pressure applying cylinder is similarly achieved by controlling the operating point of the vacuum booster by the remaining operating force, and the operating state covered by the operating piston and the vacuum booster The hydraulically actuated operating device according to any one of claims 1 to 5, wherein the operating device exclusively depends on the volume of the pressure medium required for the operation of (1). 7. The control piston comprises an axial extension which is sealed and guided in a movable wall, and on which a plate is held, said plate having a vacuum formed in the movable wall with a diaphragm approaching it. 6. The hydraulically actuated device according to claim 1, wherein the chamber is sealed and restricted. 8. The hydraulically actuated operating device according to claim 7, wherein the diaphragm is formed so as to act integrally with the rolling diaphragm of the movable wall. 9. The hydraulically actuated operating device according to claim 8, wherein the integrally formed diaphragm has a hole in the region of the path.