JPH06255470A - Fluid pressure booster - Google Patents

Abstract

PURPOSE:To downsize the whole of a device by making the opening/closing operation of the fluid pressure introduction valve of a fluid pressure booster free of the operation of an operating (input) member, and opening/closing the aforesaid operation by means of fluid pressure developed within the fluid pressure booster. CONSTITUTION:The device is equipped with a booster piston 3a partitioning a cylinder body into an output fluid pressure chamber 4 and a power pressure chamber 12, a flow valve A which is controlled by means of the relative movement of a booster piston and an input member 14 for opening/closing communication between a power fluid pressure chamber 12 and a reservoir 2, a closing valve B cutting off communication between an output fluid pressure chamber 4 and the reservoir 2, and with a fluid pressure introduction valve C communicating an accumulator AC operated by fluid pressure developed in the output pressure chamber 4 with the power pressure chamber 12. When the input member is operated, the flow valve A is closed, the closing valve B is closed, and the fluid pressure introduction valve C is opened, the fluid pressure of the accumulator AC is then supplied to the inside of the power pressure chamber 12, so that the aforesaid pressure is thereby applied to the booster piston 3a.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic booster that boosts pressure by utilizing a hydraulic pressure supplied from a hydraulic pressure source, and more particularly, a master cylinder and a hydraulic booster are integrated. The present invention relates to a small hydraulic booster.

[0002]

2. Description of the Related Art Hydraulic boosters are used, for example, in hydraulic brake systems for automobiles to boost the operating force. As disclosed in Japanese Utility Model Publication No. 3-31653, a hydraulic booster of this type generally operates in response to the operation of a power piston operated by the hydraulic pressure of a power hydraulic chamber and an operation member. An input piston and a control valve that is provided between the power piston and the input piston and that is operated by relative movement of both pistons to control the hydraulic pressure of the power hydraulic chamber are configured.

In this device, when the input piston moves forward in response to the operation of the operating member, the control valve raises the hydraulic pressure in the power hydraulic chamber, whereby the power piston moves forward and pushes the push rod of the master cylinder. Press,
The pedal force of the operator's brake pedal is reduced. At this time, the hydraulic pressure of the power hydraulic chamber is also applied to the input piston on a relatively small pressure receiving surface, and a reaction force proportional to the operating force of the power piston acts on the input piston, and the operator boosts the hydraulic pressure. It is designed to be aware of the increased output of the device.

[0004]

However, in the above hydraulic booster, a control valve for controlling the power piston is provided between the power piston and the input piston, and is operated by the relative movement of both pistons. Yes, and
Since the boosted operating force is transmitted to the push rod of the conventionally known master cylinder that is arranged in series with the power piston, the axial length of the entire device becomes long, and miniaturization is difficult. However, there is a problem in that a mounting space for that purpose is required.

Therefore, according to the present invention, the opening and closing of the control valve (hereinafter referred to as the hydraulic pressure introducing valve) of the hydraulic booster is separated from the operation of the operation member, and indirectly by the hydraulic pressure generated in the hydraulic booster. It is intended to solve the above problems by downsizing the entire device by opening and closing.

[0006]

Therefore, the present invention provides a hydraulic booster, which comprises a cylinder body 1 and
An output hydraulic chamber 4 and a power hydraulic chamber 1 which are arranged in the same cylinder body and connect the inside of the cylinder body to a wheel cylinder.
2, a booster piston 3a, a flow valve A that is controlled by relative movement of the booster piston 3a and the input member 14 to open and close communication between the power hydraulic chamber 12 and the reservoir 2, and movement of the booster piston. An on-off valve B for disconnecting the communication between the output hydraulic chamber and the reservoir by
A hydraulic pressure introducing valve C that is operated by the hydraulic pressure generated in the output hydraulic chamber and connects the accumulator AC and the power hydraulic chamber is provided. When the input member is activated, the flow valve A is closed and the reservoir 2 and the power liquid are provided. The communication with the pressure chamber 12 is cut off, then the communication between the reservoir and the output hydraulic pressure chamber is cut due to the movement of the booster piston, and the hydraulic pressure generated in the output hydraulic pressure chamber opens the hydraulic pressure introducing valve C. Accumulator AC
And the power hydraulic chamber 12 are communicated with each other, the hydraulic pressure of the accumulator AC is supplied into the power hydraulic chamber 12, and the hydraulic pressure is configured to act on the booster piston.
This is a means for solving the problem.

[0007]

When the brake pedal is stepped on, the push rod as the input member is pushed, and the communication between the reservoir and the power hydraulic chamber drops. Then, the movement of the booster piston disconnects the communication between the output hydraulic chamber that generates the hydraulic pressure and the reservoir, and the movement of the booster piston generates the hydraulic pressure in the output hydraulic chamber. Due to this hydraulic pressure, the valve piston in the hydraulic pressure introducing valve is operated, the accumulator and the power hydraulic chamber are communicated with each other, and a high hydraulic pressure is supplied to the power hydraulic chamber. The hydraulic pressure introduced into the power hydraulic chamber presses the booster piston and further generates hydraulic pressure in the output hydraulic chamber to reduce the pedal effort of the operator's brake pedal. Further, the hydraulic pressure of the power hydraulic chamber at this time also acts on the push rod, and the reaction force proportional to the operating force of the booster piston acts on the push rod, and the operator increases the output of the hydraulic booster. It has been made known.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a hydraulic booster according to an embodiment of the present invention. In the figure, 1 is a cylinder body, and in this cylinder body 1, first and second booster pistons 3a, 3b are arranged in series. Between the first booster piston 3a and the cylinder body 1, there is a power hydraulic chamber 12 having a configuration described later, and a flow valve for opening and closing a flow path to the power hydraulic chamber 12 (shown by A in FIG. 1). Are arranged. Also, the first and second booster pistons 3a, 3
The first output hydraulic chamber 4 is provided between b and the second output hydraulic chamber 4.
Between the booster piston 3b and the cylinder body of the
Is the output hydraulic chamber 4. The first and second output hydraulic chambers 4 and 5 are communicated with the reservoir 2 via an on-off valve (one of which is shown in a portion B in FIG. 1) having the same structure. Further, between the hydraulic booster and the accumulator AC, a hydraulic pressure introducing valve (indicated by C in FIG. 1) that is indirectly opened and closed by the hydraulic pressure generated in the hydraulic booster is arranged. ,
By opening and closing the hydraulic pressure introducing valve, the hydraulic pressure accumulated in the accumulator AC can be introduced into the power hydraulic chamber 12. Further, a predetermined hydraulic pressure is constantly accumulated in the accumulator AC by the hydraulic pump P. The configurations of the flow valve, the power hydraulic chamber, the on-off valve, and the hydraulic pressure introducing valve that configure the hydraulic booster will be described below.

[Flow Valve and Power Hydraulic Chamber] In FIG. 2, a valve sleeve 13 is provided at the right end of the first booster piston 3 a in the figure, and a second annular groove 13 a is provided on the inner surface of the valve sleeve 13. The second annular groove 13a is formed and communicates with the power hydraulic chamber 12 via a second flow path 13b and a flow path formed in a screw member 17 described later. At the center of the valve sleeve 13, an end portion of a push rod 14 as an input member is provided so as to be slidable in the axial direction. The push rod 14 is formed with first flow paths 14a and 14b.
A first annular groove 14c is formed on the outer peripheral surface of the push rod 14 so as to communicate with b. The flow path 14a communicates with the reservoir 2 via a liquid chamber 15 formed by the first booster piston 3a and the cylinder body 1. The annular groove 13a and the annular groove 14c constitute a valve mechanism shown in an enlarged view in FIG. This valve mechanism is normally in a communication state as shown in the figure, and has a function of disconnecting the communication when the push rod 14 is pushed.

A step portion 14d having a diameter larger than that of the end portion fitted in the valve sleeve 13 is formed on the push rod 14, and a flow of the valve mechanism is provided between the step portion 14d and the valve sleeve 13. A gap L is formed that can secure a sufficient amount of movement to open and close the road. The gap L communicates with the power hydraulic chamber 12 through a gap formed between the push rod 14 and the screw member 17. The screw member 17 is screwed into the valve sleeve 13 and has a function of restricting the amount of axial movement of the push rod 14. A spring 18 is provided between the push rod 14 and the first booster piston 3a,
The push rod 14 is normally urged rightward in the figure by the spring 18. The power hydraulic chamber 12 is formed between the booster piston 3 a and the spacer 19, and the spacer 19 is attached to the cylinder body 1 by the plug 20 and the screw member 22. Also,
The power hydraulic chamber 12 is connected to a hydraulic pressure introducing valve described later by a flow path 21.

The flow valve constructed as described above always maintains the state shown in the figure, but the brake pedal is stepped on and the push rod 14 moves against the urging force of the spring 18. When pushed to the left in the middle, the push rod 14 first moves the distance of the gap L, thereby cutting off the communication between the annular groove 13a and the annular groove 14c (that is, the communication between the reservoir and the power hydraulic chamber 12). cut off). Then, the large-diameter portion 14b of the push rod 14 contacts the valve sleeve 13, presses the first booster piston 3a leftward via the valve sleeve 13, and applies hydraulic pressure to the first output hydraulic chamber 4 described later. Occur. At this time, a high-pressure hydraulic pressure from the accumulator is introduced into the power hydraulic chamber 12 from the flow path 21 via the hydraulic pressure introduction valve described later, and the booster piston 3a is pressed to the left by this hydraulic pressure, so that the operator The pedal force of the brake pedal is reduced. At this time, the hydraulic pressure of the power hydraulic chamber 12 also acts on the push rod 14 by the hydraulic pressure introduced into the gap L, so that a reaction force proportional to the operating force of the booster piston acts on the push rod to operate. It is made possible for a person to be aware of an increase in the output of a hydraulic booster.

[Open / Close Valve] The open / close valve is a valve for controlling communication between the first and second output hydraulic chambers 4 and 5 and the reservoir 2. The structure of the open / close valve will be described with reference to FIG. Then, the on-off valve is a valve member 7 for opening and closing the communication between the flow passage 6 formed in the second booster piston 3b or the cylinder body 1 and the output hydraulic chamber 4 or the output hydraulic chamber 5.
A spring 8 that keeps the valve member 7 normally open, and a spring 9 that moves the valve member 7 and shuts off the flow path 6 when the push rod is operated and the spring 8 is in a compressed state. It is configured. The valve member 7 is slidably provided on the washers 10 and 11.

In this on-off valve, when the push rod 14 is operated, the first booster piston moves leftward in FIG. 1 and compresses the spring 8, which causes the spring 9 to move.
Moves the valve member 7 to the left to close the flow path 6 and disconnect the communication with the reservoir 2. Then, a hydraulic pressure is generated in the first output hydraulic chamber 4, and this hydraulic pressure is supplied to the wheel cylinder and moves the second booster piston 3b leftward in FIG. By the movement of the booster piston 3b, the on-off valve closes the flow path 6 and disconnects the communication between the reservoir 2 and the second output hydraulic pressure chamber 5 in the same manner as above. As a result, hydraulic pressure is generated in the second output hydraulic chamber,
This hydraulic pressure is supplied to the wheel cylinder.

[Liquid Pressure Introducing Valve] The hydraulic pressure introducing valve is a valve for introducing the hydraulic pressure accumulated in the accumulator AC shown in FIG. 1 into the power hydraulic chamber 12. This hydraulic pressure introduction valve is shown in Fig. 1.
As shown in FIG. 5, it is arranged between the hydraulic booster and the accumulator and is indirectly opened / closed by the hydraulic pressure generated in the hydraulic booster. In FIG. 1, a valve body 24 is attached to the cylinder body 1, and an elongated hole 28 communicating with the first and second output hydraulic chambers 4 and 5 and the wheel cylinder is installed in the valve body 24. Are formed. The long hole 28 is an accumulator AC.
And a flow path 21 communicating with the power hydraulic chamber 12
And a flow path 27 communicating with the liquid chamber 15. The fail-safe piston 25 is in the long hole 28.
And a valve piston 26 are provided, the fail-safe piston 25 communicates the second output hydraulic chamber 5 with the wheel cylinder, and the first and second holes 28 inside the elongated hole 28.
The output fluid pressure chambers 4 and 5 are disconnected from each other. Further, the valve piston 26 communicates the first output hydraulic chamber 4 with the wheel cylinder. The fail safe 25 and the valve piston 26 are connected to the first and second output hydraulic pressure chambers 4 and 5, respectively.
It is possible to move to the right in the figure by the hydraulic pressure generated at.

In FIG. 4, a valve sleeve 31 is attached to the valve body 24, and the valve piston 26 is slidably arranged in the valve sleeve 31. Valve sleeve 31 and valve piston 26
A spring 32 is disposed between and, and the valve piston 26 is constantly urged to the left in the figure by this spring. The valve sleeve 31 is provided with a flow passage 31a communicating with the accumulator AC and a flow passage 31b connected to the flow passage 21 communicating with the power hydraulic chamber 12, and the flow passage 31a communicates with the flow passage 31a. An annular groove 31c is formed on the inner peripheral surface of the sleeve 31. On the other hand, the valve piston 26 has a flow passage 30 which is in constant communication with the flow passage 31b.
Is formed, and the flow passage 30 is formed by the valve piston 26.
It communicates with the annular groove 29 formed on the outer periphery of the. The annular grooves 31c and 29 constitute a hydraulic pressure introducing valve mechanism, and the communication between the annular grooves 31c and 29 is normally disconnected as shown in the figure.

When the push rod is pushed, the first and second
When hydraulic pressure is generated in the output hydraulic chambers 4 and 5, the failsafe 25 and the valve piston 26 move to the right in the figure against the biasing force of the spring 32 due to this hydraulic pressure. As a result, the annular grooves 31c and 29 are communicated with each other, and the high-pressure hydraulic pressure from the accumulator is passed through the flow passage 31a → the annular groove 31.
c → annular groove 29 → passage 30 → passage 31b → passage 21 → power hydraulic chamber 12 and is supplied to the booster piston 3a. When a failure occurs in the first hydraulic pressure chamber system, the valve piston 26 can be operated via the fail-safe piston 25 with the hydraulic pressure in the second hydraulic pressure chamber system. When a failure occurs in the second hydraulic chamber system, the valve piston 26 can be operated by the hydraulic pressure of the first hydraulic chamber system, and the safety is improved.

This embodiment is constructed as described above,
It works as follows. The hydraulic booster always maintains the state shown in the figure, but the brake pedal is depressed,
When the push rod 14 is pushed to the left in the figure against the urging force of the spring 18, the push rod 14 first moves by the gap L, thereby disconnecting the communication between the annular groove 13a and the annular groove 14c. The communication between the power hydraulic chamber and the reservoir is cut off. Then, the push rod 14 contacts the valve sleeve 13 and presses the first booster piston leftward via the valve sleeve 13. The leftward movement of the first booster piston 3a compresses the spring 8, which causes the spring 9 to move the valve member 7 leftward and close the flow path 6. Then, a hydraulic pressure is generated in the first output hydraulic chamber 4, and this hydraulic pressure is supplied to the wheel cylinder and moves the second booster piston 3b leftward in FIG. As a result, the second output hydraulic pressure chamber 5 is also shut off from the flow path 6 by the opening / closing valve, a hydraulic pressure is generated in the second output hydraulic pressure chamber, and this hydraulic pressure is supplied to the wheel cylinder.

The hydraulic pressure generated in the first and second output hydraulic chambers also acts on the fail safe 25 and the valve piston 26. As a result, the valve piston 26 moves to the right in the figure against the biasing force of the spring 32. By the movement of the valve piston 26, the annular grooves 31c and 29 are communicated with each other, and the high-pressure hydraulic pressure from the accumulator is applied to the flow passage 31.
a → annular groove 31c → annular groove 29 → passage 30 → passage 31b
→ Flow path 21 → Power is supplied to the hydraulic chamber 12. The hydraulic pressure introduced into the power hydraulic chamber 12 presses the booster piston 3a to the left to reduce the pedal effort of the brake pedal of the operator. Further, the hydraulic pressure of the power hydraulic chamber at this time also acts on the push rod by the hydraulic pressure introduced into the gap L, so that a reaction force proportional to the operating force of the booster piston acts on the push rod, and the operator It is intended to be aware of the increased output of hydraulic boosters.

When a failure occurs in the first hydraulic chamber system, the valve piston 26 can be operated via the fail-safe piston 25 with the hydraulic pressure of the second hydraulic chamber system, Further, when a failure occurs in the second hydraulic pressure chamber system, the valve piston 26 can be operated by the hydraulic pressure of the first hydraulic pressure chamber system, and the safety is improved.

[0020]

As described in detail above, according to the present invention,
Since the opening and closing of the hydraulic pressure introduction valve of the hydraulic booster is separated from the operation of the operating member and is indirectly opened and closed by the hydraulic pressure generated in the hydraulic booster, the entire device can be operated with the conventional hydraulic pressure. It is possible to achieve a smaller size than the booster, and further, it is possible to achieve excellent effects such as weight reduction and cost reduction of the device.

[Brief description of drawings]

FIG. 1 is a side sectional view of a hydraulic booster according to an embodiment of the present invention.

FIG. 2 is an enlarged view of part A in FIG.

FIG. 3 is an enlarged view of part B in FIG.

FIG. 4 is an enlarged view of a C portion in FIG.

[Explanation of symbols]

 1 Cylinder body 2 Reservoir 3a First booster piston 3b Second booster piston 4 First output hydraulic chamber 5 Second output hydraulic chamber 6 Flow path 7 Valve member 8, 9 Spring 10, 11 Washer 12 Power hydraulic chamber 13, 31 Valve sleeve 14 Input member (push rod) 15 Liquid chamber 25 Fail-safe piston 26 Valve piston AC accumulator P Pump A Flow valve B Open / close valve C Liquid pressure introduction valve

Claims (5)

[Claims] 1. A hydraulic booster comprising: a cylinder body 1; and an output hydraulic chamber 4 arranged in the cylinder body and connected to a wheel cylinder in the cylinder body.
And the booster piston 3a which divides into the power hydraulic chamber 12
And a flow valve A that is controlled by relative movement of the booster piston 3a and the input member 14 to open and close communication between the power hydraulic chamber 12 and the reservoir 2, and the output hydraulic chamber and the reservoir by movement of the booster piston. An on-off valve B for disconnecting the communication with the hydraulic pressure introducing valve C, which is operated by the hydraulic pressure generated in the output hydraulic pressure chamber and connects the accumulator AC and the power hydraulic pressure chamber, is provided. The valve A is closed to disconnect the communication between the reservoir 2 and the power hydraulic chamber 12, and then the communication between the reservoir and the hydraulic chamber is disconnected due to the movement of the booster piston, so that the hydraulic pressure generated in the output hydraulic chamber. As a result, the hydraulic pressure introduction valve C is opened, the accumulator AC and the power hydraulic chamber 12 are communicated with each other, the hydraulic pressure of the accumulator AC is supplied into the power hydraulic chamber 12, and this hydraulic pressure is boosted. Hydraulic booster, characterized in that it is configured to act on the piston. 2. The flow valve A comprises a booster piston 3a.
Valve sleeve 13 provided in the
3, an input member 14 provided slidably in the center in the axial direction, and first flow paths 14 a, 14 formed in the input member 14.
b and a first annular groove 14c communicating with the first flow path 14b and formed on the outer peripheral surface, and a second annular groove 13a formed on the inner surface of the valve sleeve 13, the second annular groove 13a.
2. The hydraulic booster according to claim 1, wherein the first fluid passage 14a communicates with the power hydraulic chamber 12 through the second fluid passage 13b, and the first fluid passage 14a communicates with the reservoir 2. . 3. The on-off valve B is a valve member 7 for opening and closing the communication between the output hydraulic chamber and the reservoir, and the valve member 7
Is constituted by a spring 8 for always maintaining the open state, and a spring 9 for moving the valve member 7 and shutting off the flow path 6 when the push rod is operated and the spring 8 is in the compressed state. The hydraulic booster according to claim 1, which is characterized in that. 4. The fluid pressure introducing valve C comprises a valve body 24.
And a valve piston 26 which is slidably arranged in the valve body 24 and controls the communication between the power hydraulic chamber 12 and the accumulator. The valve piston is moved by the hydraulic pressure generated in the hydraulic chamber. The hydraulic booster according to claim 1, wherein the hydraulic booster is configured to connect the accumulator AC and the power hydraulic chamber 12 with each other. 5. The valve piston 26 receives the hydraulic pressure of one system of the brake system piping system separated into two systems, and one end receives the hydraulic pressure of the other system coaxially with the valve piston 26, The hydraulic booster according to claim 4, further comprising a fail-safe piston 25, the other end of which is in contact with the valve piston 26.