JPH08198093A - Braking hydraulic pressure control device - Google Patents

Abstract

PURPOSE: To depress a variation in reaction force acting on a brake actuation member and to enhance brake feeling by providing a rubber elastic body between the front end of an interlocking piston slidably engaging with a cylinder body by facing its back face to a pressure chamber and a fixing receiving part fixed to the cylinder body. CONSTITUTION: Load transferring means 75 housed in a skirt part 35a is provided between the front end of an interlocking piston 35 and the fixing receiving part 61 of a cylinder body 27. The load transferring means 75 is composed of a rubber elastic body 77 provided between a pressing member 76 abutted to the detecting part 61a of a load sensor S1 and the interlocking piston 35. Thus, the rubber elastic body 77 is provided between the front end of the interlocking piston 35 and the fixing receiving part 61. As a result, even if actuation force on a brake pedal is sudden one, its load is absorbed by the rubber elastic body 77, acting no impact load on the load sensor S1 . In addition, the rubber elastic body 77 also absorbs a low variation in reaction force acting on the brake pedal to enhance actuation feeling.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a master cylinder in which an operating piston which is interlocked with and connected to a brake operating member is slidably fitted to a cylinder body with its front surface facing a pressure chamber, and the master cylinder. Braking hydraulic pressure generating means capable of generating a braking hydraulic pressure higher than the output hydraulic pressure of the cylinder, a state in which the output hydraulic pressure of the master cylinder is applied to the wheel brakes, and the output hydraulic pressure of the braking hydraulic pressure generating means to the wheel brakes. The present invention relates to a braking fluid pressure control device that includes a switching unit that selectively switches operating states.

[0002]

2. Description of the Related Art Conventionally, such a braking hydraulic pressure control device is already known, for example, from Japanese Patent Laid-Open No. 61-155047.

[0003]

In the conventional master cylinder described above, between the end wall of the cylinder body and the front working piston, and between the rear working piston and the front working piston which are interlocked and connected to the brake operating member. Each pressure chamber is formed. Therefore, the reaction force change generated in the pressure chamber is directly transmitted to the brake operating member, and it is hard to say that the brake feeling is excellent.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a braking fluid pressure control device in which the fluctuation of the reaction force acting on the brake operating member is suppressed and the brake feeling is improved. To do.

[0005]

In order to achieve the above-mentioned object, the present invention is such that an actuating piston that is interlocked with and connected to a brake operating member is slidably fitted to a cylinder body with its front face facing the pressure chamber. Combined master cylinder, braking fluid pressure generation means capable of generating a braking fluid pressure higher than the output fluid pressure of the master cylinder, a state in which the output fluid pressure of the master cylinder is applied to the wheel brakes, and the braking fluid pressure. In a braking fluid pressure control device comprising a switching means for selectively switching a state in which an output fluid pressure of a generating means is applied to a wheel brake, the braking fluid pressure control device is slidably fitted to a cylinder body with a back surface thereof facing a pressure chamber. A rubber elastic body is interposed between a front end of the interlocking piston and a fixed receiving portion fixed to the cylinder body.

[0006]

[Function] The rubber elastic body interposed between the interlocking piston and the fixed receiving portion causes hysteresis loss. The energy applied during the deformation process and the energy released during the recovery process in the deformation / recovery cycle are Due to the difference between the two, even if the reaction force generated in the pressure chamber fluctuates within a relatively small range, the change in the reaction force is absorbed by the rubber elastic body.

[0007]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 3 show a first embodiment of the present invention. FIG. 1 is an overall hydraulic circuit diagram, FIG. 2 is a vertical sectional side view of a master cylinder, and FIG. It is a figure.

First, in FIG. 1, this brake fluid pressure control device outputs a brake fluid pressure in accordance with a depression operation of a brake pedal 1 as a brake operating member.
A braking hydraulic pressure generating means A capable of generating a braking hydraulic pressure higher than the output hydraulic pressure of the master cylinder M, a state in which the output hydraulic pressure of the master cylinder M is applied to the wheel brake B, and the braking hydraulic pressure generating means A. And a switching valve 7 as switching means for selectively switching the state in which the output hydraulic pressure is applied to the wheel brake B.

The braking hydraulic pressure generating means A includes a hydraulic pressure supply source 4,
It is composed of a hydraulic pressure control valve 5 connected to the hydraulic pressure supply source 4, and a linear solenoid 6 for operating the hydraulic pressure control valve 5.

The hydraulic pressure supply source 4 includes a hydraulic pump 10 for pumping hydraulic fluid from a reservoir 9, an accumulator 11 connected to the hydraulic pump 10, and a pressure switch for controlling the operation of the hydraulic pump 10. 12 and.

The linear solenoid 6 applies a forward thrust to the hydraulic pressure control valve 5 according to the amount of exciting current of the coil 23, and the amount of exciting current of the coil 23 corresponds to the amount of depression of the brake pedal 1. It is controlled by the electronic control unit 8 based on the detection value of the load sensor S ₁ which detects the corresponding value.

The hydraulic pressure control valve 5 has an output port 18, an input port 19 communicating with the hydraulic pressure supply source 4, and a release port 20 communicating with the reservoir 9, and the hydraulic pressure supply source 4
Is adjusted to a value according to the thrust applied from the linear solenoid 6 and output from the output port 18.

The switching valve 7 is the output port 1 of the hydraulic pressure control valve 5.
8 is a 3-port 2-position switching valve that performs switching operation using the hydraulic pressure output from No. 8 as a pilot pressure. When the hydraulic pressure of a predetermined value or more is output from the output port 18, the output port 18 of the hydraulic pressure control valve 5 is connected to the wheel. It is possible to switch between a position for communicating with the brake B and a position for communicating the output port 36 of the master cylinder M with the wheel brake B when the output hydraulic pressure of the output port 18 is less than a predetermined value. Thus, the switching valve 7 is in a state in which the output port 18 of the hydraulic pressure control valve 5 is in communication with the wheel brake B during normal braking, but the hydraulic pressure is reduced due to a failure of the hydraulic pressure supply source 4 and the linear solenoid 6, or the like. When it becomes difficult to obtain the braking pressure from the output port 18 of the control valve 5, the output port 36 of the master cylinder M is brought into communication with the wheel brake B.

Between the output port 36 of the master cylinder M and the switching valve 7, the brake pedal 1 is depressed when the switching valve 7 communicates the output port 18 of the hydraulic control valve 5 with the wheel brake B. A stroke accumulator 26 for ensuring a stroke is connected.

In FIG. 2, in the cylinder body 27 of the master cylinder M, a screw hole 28, a large-diameter cylinder hole 29, and a small-diameter cylinder hole 30 having a smaller diameter than the large-diameter cylinder hole 29 are arranged in this order from the front end side. A fitting hole 31 having a diameter larger than that of the small-diameter cylinder hole 30 is sequentially and coaxially provided, and the small-diameter cylinder hole 30 is provided with a cup seal 32, which is in sliding contact with the inner surface of the cylinder hole 30, on the outer circumference. 33
And an interlocking piston 35 that forms a pressure chamber 34 between the operating piston 33 and the working piston 33, and a cup seal 37 that slidably contacts the inner surface of the small diameter cylinder hole 30 is attached to the outer periphery of the interlocking piston 35. To be done. Further, the cylinder body 27 is provided with an output port 36 which is in constant communication with the pressure chamber 34,
The output port 36 is connected to the switching valve 7.

A piston rod 39, which is slidably supported by a bearing member 38 fitted in the fitting hole 31, is coaxially and integrally connected to the working piston 33. A push rod 40 connected to the brake pedal 1 (see FIG. 1) is connected so as to be swingable.

In the pressure chamber 34, a space is provided between the working piston 33 and the interlocking piston 35, and both pistons 33, 35 are contracted.
Return spring 4 that exerts a spring force in the direction that separates each other
1 is stored.

An annular replenishing liquid chamber 43 is defined between the working piston 33 and the bearing member 38. On the other hand, a reservoir 45 is attached to the liquid reservoir 44 provided above the cylinder body 27, and the replenishment liquid chamber 43 is connected to the liquid reservoir 4 in the reservoir 45.
The cylinder body 27 is provided with a relief port 46 communicating with the cylinder 4. Thus, the cup seal 32 is provided in the replenishing liquid chamber 43.
It is mounted on the outer circumference of the working piston 33 at a position further forward than the working piston 33, and the working piston 33 is provided with a communication hole 47 for communicating the replenishment liquid chamber 43 with the back surface of the cup seal 32.

A central relief valve 48 is provided between the replenishing liquid chamber 43 and the pressure chamber 34. This relief valve 48
Is a valve box 49 that is coaxially attached to the front end portion of the operating piston 33, and is drilled coaxially with the operating piston 33 by communicating with the replenishing liquid chamber 43.
Of the valve hole 50, which is opened in the front end of the valve hole 50, a valve body 51 which is housed in the valve box 49 so that the front end opening of the valve hole 50 can be closed, and is movable back and forth. When the operating piston 33 is in the retreat limit, the valve element 51 exerts a spring force for urging the valve spring 51 in the forward direction and moves the valve element 51 against the spring urging force of the valve spring 52 to the forward position. Is held at the valve spring 52 when the working piston 33 moves forward.
And a valve opening rod 53 that allows the valve body 51 to move backward, that is, to close the valve.

The operating piston 33 has the operating piston 3
3, a long hole 54 is provided in the axial direction, and both ends of the long hole 54 communicate with the replenishing liquid chamber 43. The valve opening rod 53 has a long hole 54.
Both ends of the valve opening rod 53 are supported by a support ring 55 that surrounds the piston rod 39. Further, although not clearly shown, a spring is contracted between the working piston 33 and the support ring 55, and the support ring 55 is urged by the spring force in a direction to be received by the bearing member 38.

The valve hole 50 includes an elongated hole 54 and an operating piston 33.
The rod 5 which is provided over the front end portion of the rod 5 and is integrally connected to the valve body 51 and inserted into the valve hole 50.
The rear end of 6 is brought into contact with the valve opening rod 53.

According to such a relief valve 48, when the working piston 33 is in the retracted limit, the rod 56 is pressed by the valve opening rod 53 so that the valve body 51 is in a position to open the valve hole 50. By opening the valve, the replenishing liquid from the replenishing liquid chamber 43 can be replenished to the pressure chamber 34. Also the working piston 33
Is moved forward from the backward limit, the valve opening rod 53 moves relative to the actuating piston 33 so that the valve opening rod 53 is positioned rearward in the elongated hole 54, so that the valve body 51 moves the valve hole 50 by the spring force of the valve spring 52. It moves to the closed position, and the replenishing liquid chamber 43 and the pressure chamber 34 are shut off from each other.

Referring also to FIG. 3, the housing 60 of the load sensor S ₁ has a housing main body 61 formed in a cylindrical shape with a bottom, and the housing main body 61 is formed by closing the opening of the housing main body 61. Lid member 6 to be caulked
2, the housing main body 61 is provided with a detection portion 61a protruding like a pin on the outer surface of the central portion of the closed end. The lid member 62 is made of a non-conductive material such as synthetic resin, and a connector (not shown) connected to a connection line for guiding a signal from the load sensor S is inserted into and removed from the lid member 62. A coupler 62a for integrally connecting is provided integrally.

In such a load sensor S ₁ , a male screw 74 is engraved on the outer surface of the housing main body 61, and the male screw 74 is screwed into the screw hole 28 of the cylinder body 27 to make the load sensor S ₁ Is attached to the master cylinder M.

The cylinder body 27 is slid into the small diameter cylinder hole 30.
The interlocking piston 35 that is movably fitted has a cylinder
Load sensor S attached to the front end of the body 27₁Smell
The cylinder body 27 is
A cylindrical ska slidably fitted in the diameter cylinder hole 29.
The load sensor S is provided integrally with the load sensor 35a. ₁
In the portion of the housing 60 other than the detecting portion 61a.
When the skirt portion 35a abuts, the interlocking piston 3
A forward limit of 5 is defined.

The front end of the interlocking piston 35 and the cylinder body 2
Housing main body 61 as a fixed receiving portion fixed to
A load transmission means 75 is provided between the load transmission means 75 and the skirt portion 35a so as to be housed in the skirt portion 35a. The pressing member 76 and the interlocking piston 35
The rubber elastic body 77 is interposed between the rubber elastic body 77 and the rubber elastic body 77. The rubber elastic body 77 is made of natural rubber or synthetic rubber.

The pressing member 76 has a flange portion 76a protruding outward in the radial direction so as to bring the outer edge thereof close to the inner surface of the skirt portion 35a, and a rubber elastic body protruding from the central portion of the flange portion 76a toward the interlocking piston 35. The rubber elastic body 77 is arranged between the flange portion 76 a of the pressing member 76 and the interlocking piston 35.

By the way, as shown in FIG. 2, the operating piston 33 and the interlocking piston 35 are operated during non-brake operation.
Is in the backward limit, the distance L ₁ between the shaft portion 76b of the pressing member 76 and the interlocking piston 35 is
Skirt portion 35a and the housing 60 of the load sensor S ₁
It is set such that the distance L _{2 is} more than L ₂ (L ₁ ≧ L ₂ ). As a result, when the interlocking piston 35 moves to the side closer to the load sensor S ₁ , direct load transmission from the interlocking piston 35 to the pressing member 76 is avoided, and the load from the interlocking piston 35 causes the rubber elastic body 77 to move. It will always be given to the load sensor S ₁ via.

Next, the operation of the first embodiment will be described.
Then, the output of the braking hydraulic pressure generating means A, that is, the hydraulic pressure control valve 5
When normal braking pressure can be obtained from port 18
Changes the switching valve 7 according to the depression operation of the brake pedal 1.
Connect output port 18 of hydraulic control valve 5 to wheel brake B
The brake pedal 1 is depressed in this state.
Including operating force is load sensor S₁Detected by. Ie work
When the moving piston 33 moves forward, the relief valve 48 is closed.
In the initial stage of operation until twisting, the operating force is returned via the return spring 41.
Transmitted to the interlocking piston 35, the relief valve 48 closed
Later, the pressure generated in response to the forward movement of the working piston 33
Let the hydraulic pressure in the chamber 34 act on the back surface of the interlocking piston 35.
The load from the interlocking piston 35 is transmitted.
Load sensor S via reaching means 75₁To the detector 61a of
By using the load sensor S ₁And brake pedal 1
The stepping force of is detected. Thus, braking fluid pressure generating means
The exciting current amount of the linear solenoid 6 in A is
Sensor S₁Is controlled by the electronic control unit 8 according to the detected value of
The operating force of the brake pedal 1 is controlled accordingly.
The brake fluid pressure amplified corresponding to the above acts on the wheel brake B.
Will be.

At this time, the operating force of the brake pedal 1 is suddenly increased.
Even if the interlocking piston 35 and the load sensor S₁while
The load transmission means 75 provided in the
The rubber elastic body 77 absorbs a sudden load.
Load sensor S ₁A shocking load is applied to
Can be avoided. Also the interlocking piston 35
Of the skirt 35 of the interlocking piston 35
When a contacts the housing 60 of the load sensor S,
Is regulated, the load sensor S₁Made by
It can also be avoided. Therefore, the load
Sensor S₁The impact load or excessive load on
Prevent both and load sensor S₁To prevent damage
it can.

The rubber elastic body 77 has a hysteresis characteristic that causes a difference between the energy applied in the deformation process and the energy released in the recovery process in the deformation / recovery cycle. The relatively small hydraulic pressure fluctuation is absorbed by the rubber elastic body 77. Therefore, the rubber elastic body 77 also absorbs a relatively small change in the reaction force acting on the brake pedal 1 side from the pressure chamber 34, and the operation feeling of the brake pedal 1 can be improved. Moreover the load acting on the load sensor S ₁ stabilized, it is possible to enable stable operation force detection by the load sensor S _1, thereby braking fluid pressure generating means A
It is possible to control stably.

By the way, when a hydraulic pressure failure occurs in the hydraulic system from the output port 36 of the master cylinder M to the switching valve 7, the reaction force is not applied to the front surface of the working piston 33 by the depression operation of the brake pedal 1. Due to this, it moves until it comes into contact with the interlocking piston 35. In this state, the stepping operation force that directly acts on the interlocking piston 35 from the actuating piston 33 is applied to the rubber elastic body 77 and the rubber elastic body 77. The generated load can be detected by the load sensor S ₁ . Therefore, the load sensor S ₁ can detect the load corresponding to the stepping operation force even when the hydraulic pressure failure occurs, and the load sensor S ₁
It is possible to apply the braking fluid pressure corresponding to the detected value of 1 to the wheel brake B from the fluid pressure control valve 5.

FIG. 4 shows a second embodiment of the present invention, and the portions corresponding to those of the first embodiment are designated by the same reference numerals.

A working piston 33 and an interlocking piston 35 'forming a pressure chamber 34 between the working piston 33 are slidably fitted to the cylinder body 27' of the master cylinder M '. Further, the front end wall 27a 'of the cylinder body 27' is
Serves as a fixed receiving portion fixed to the cylinder body 27 ′, and includes the interlocking piston 35 ′ and the front end wall 2.
A rubber elastic body 77 'is provided between 7a'.

The load sensor S ₂ for detecting the operating force of the brake pedal 1 (see FIG. 1) is a push rod 40 for transmitting the operating force of the brake pedal 1 to the working piston 33.
Is installed in the middle part of.

According to this second embodiment, the rubber elastic body 77 is also used.
It is possible to improve the brake feeling by absorbing a relatively small reaction force variation.

Further, as in the third embodiment shown in FIG. 5, the pressure sensor S ₃ is connected to the hydraulic pressure passage connected to the output port 36 of the master cylinder M ', and the operating force is detected by this pressure sensor S _3. Is also possible.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the claims. It is possible to do.

For example, the braking hydraulic pressure generating means may be constituted by a motor connected to a piston facing the hydraulic pressure generating chamber via a ball screw, and the switching means may be the output fluid of the master cylinder. The high-select valve may be configured so that either the pressure or the output hydraulic pressure of the braking hydraulic pressure generating means is selectively selected to act on the wheel brakes, and the switching means is electrically connected. It may be a solenoid valve that is switched.

[0041]

As described above, according to the present invention, the front end of the interlocking piston, which is slidably fitted to the cylinder body with the back surface facing the pressure chamber, and the fixed receiving portion fixedly mounted on the cylinder body. Since the rubber elastic body is interposed between the rubber elastic body and the rubber elastic body, the hysteresis characteristic of the rubber elastic body can absorb the reaction force fluctuation acting on the brake operating member, and the brake feeling can be improved.

[Brief description of drawings]

FIG. 1 is an overall hydraulic circuit diagram of a first embodiment.

FIG. 2 is a vertical sectional side view of a master cylinder.

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

FIG. 4 is a vertical sectional side view of a master cylinder of a second embodiment.

FIG. 5 is a sectional view of a third embodiment corresponding to FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Brake pedal as brake operating member 7 ... Switching valve 27 as switching means 27, 27 '... Cylinder body 27a' ... Front end wall as fixed receiving portion 33 ... Working piston 34. ..Pressure chambers 35, 35 '... Interlocking piston 61 ... Housing main body as fixed receiving portion 77, 77' ... Rubber elastic body A ... Braking hydraulic pressure generating means B ... Wheel brake M , M '... Master cylinder

Claims (1)

[Claims] 1. An operating piston (33) interlockingly connected to a brake operating member (1) has a pressure chamber (34) on its front surface.
Of the master cylinder (M, M ') slidably fitted to the cylinder body (27, 27') facing the vehicle, and braking greater than the output hydraulic pressure of the master cylinder (M, M '). Brake hydraulic pressure generating means (A) capable of generating hydraulic pressure, a state in which the output hydraulic pressure of the master cylinder (M, M ') is applied to the wheel brake (B), and the output hydraulic pressure of the braking hydraulic pressure generating means (A). In a braking fluid pressure control device comprising a switching means (7) for selectively switching a state in which a pressure is applied to a wheel brake (B), a cylinder body (27, 27 ') with its rear surface facing the pressure chamber (34). ) And the front end of the interlocking piston (35, 35 ') slidably fitted to the cylinder body (27, 27').
A braking hydraulic pressure control device, characterized in that a rubber elastic body (77, 77 ') is interposed between the fixed receiving portion (61, 27a') fixedly mounted on the ???