JPH08230652A - Brake hydraulic controller for vehicle - Google Patents

Abstract

PURPOSE: To prevent any delay in rising of braking hydraulic pressure at low cost constitution in a brake hydraulic controller for a vehicle by interposing a fail-safe valve coming in such state as interruption when a brake pedal is not subjected to push-pressing operation, and as communication when the brake pedal is subjected to push-pressing operation, between a hydraulic pressure supply source and a hydraulic control valve. CONSTITUTION: When a brake pedal 1 is stepped on to make brake operation, the operational piston and the linking piston of a master cylinder 2 advance. Thereby, the body of a fail-safe valve 61 advances and communication is provided between an input hole and an output hole. A control means 6 excites the coil of a linear solenoid 13 and control hydraulic pressure acts on each of wheel brakes BFL, BFR, BRL and BRR from the output port 21 of a hydraulic control valve 12. Any mis-operation of wheel brakes BFL, BFR, BRL and BRR is prevented from taking place on account of any trouble in an electric system by interrupting the communication between a hydraulic pressure supply source 4 and the hydraulic control valve 12 with the fail-save valve 61 in its closed state, in the case of no brake operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operating force detector for detecting an operating force of a brake pedal, a hydraulic pressure supply source, an electric actuator, and an output hydraulic pressure of the hydraulic pressure supply source for an electric actuator. A braking fluid for a vehicle including a hydraulic pressure control valve capable of adjusting the hydraulic pressure according to the operation and acting on the wheel brake, and a control means for controlling the operation of the electric actuator according to the detection value of the operating force detector. The present invention relates to a pressure control device.

[0002]

2. Description of the Related Art Conventionally, such a vehicle braking hydraulic pressure control device is disclosed in, for example, Japanese Patent Application Laid-Open Nos. 1-178062 and 6-1994.
It is known from JP-A-92213 and JP-A-4-107369.

[0003]

By the way, the braking fluid pressure control device disclosed in the above-mentioned Japanese Patent Laid-Open No. 1-178062 is designed to perform precise braking fluid pressure control with a simple structure. Since the hydraulic pressure control valve is operated by the electric actuator, there is a possibility that the electric actuator may operate due to a failure of the electric circuit when the brake operation is not performed.

Therefore, in the prior art disclosed in Japanese Unexamined Patent Publication No. 6-92213, a fail-safe valve that is interlocked with and linked to a brake pedal is provided between the output port of the hydraulic control valve and the reservoir. When the brake pedal is not operated, the fail-safe valve connects the output port of the hydraulic pressure control valve to the reservoir, and when the brake pedal is operated, the output port of the hydraulic pressure control valve and the reservoir are shut off from each other. As a result, even if the hydraulic control valve is undesirably operated during the non-brake operation due to the malfunction of the electric actuator, the braking hydraulic pressure does not act on the wheel brakes. However, because the high output hydraulic pressure from the hydraulic pressure source remains acting on the hydraulic pressure control valve during non-brake operation, hydraulic pressure is locked by the hydraulic pressure control valve, and the driving force of the electric actuator is increased during braking operation. There is a problem that the hydraulic pressure control valve does not operate until the value exceeds the value that overcomes the hydraulic pressure lock, and the rise of the braking hydraulic pressure is delayed.

Therefore, in Japanese Patent Laid-Open No. 4-107369, an electromagnetic opening / closing valve is provided between the hydraulic pressure control valve and the hydraulic pressure supply source, and the electromagnetic opening / closing is performed when the hydraulic pressure control valve is operated by an electric actuator. By opening the valve, the hydraulic lock is prevented from occurring in the hydraulic control valve. However, an expensive electromagnetic on-off valve is required only to prevent hydraulic lock, resulting in an increase in cost.

The present invention has been made in view of the above circumstances, and has a low-cost structure to prevent a delay in the rising of the braking hydraulic pressure, and the braking hydraulic pressure from the hydraulic control valve is applied to the wheel brakes during non-brake operation. It is an object of the present invention to provide a braking fluid pressure control device for a vehicle, which is surely prevented from acting on the vehicle.

[0007]

In order to achieve the above object, the present invention provides an operating force detector for detecting an operating force of a brake pedal, a hydraulic pressure supply source, an electric actuator,
A hydraulic pressure control valve capable of adjusting the output hydraulic pressure of the hydraulic pressure supply source to a hydraulic pressure corresponding to the operation of the electric actuator and acting on the wheel brake, and an electric actuator depending on the detection value of the operating force detector. In the vehicular braking hydraulic pressure control device including a control means for controlling the operation of the hydraulic pressure control device, between the hydraulic pressure supply source and the hydraulic pressure control valve, the hydraulic pressure supply source and the hydraulic pressure control valve are connected when the brake pedal is not pressed. The fail-safe valve is installed to interlock with the brake pedal to switch between the shut-off state and the state in which the hydraulic pressure supply source and the hydraulic pressure control valve communicate with each other when the brake pedal is pressed. It is characterized by

[0008]

According to the above construction, the fail-safe valve shuts off the connection between the hydraulic pressure supply source and the hydraulic control valve when the brake pedal is not pressed, so that the wheel brake can be operated even if the electric actuator malfunctions. The braking fluid pressure does not act. In addition, the valve body of the fail-safe valve is linked and connected to the brake pedal, and even if the high-pressure hydraulic pressure from the hydraulic pressure source acts to cause hydraulic lock in the fail-safe valve, The failsafe valve can be operated reliably by causing the brake pedal pushing force of the vehicle driver to act on the failsafe valve.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

1 to 4 show an embodiment in which the present invention is applied to a braking hydraulic pressure control device for a front wheel drive vehicle. FIG. 1 is an overall hydraulic pressure circuit diagram, and FIG. 2 is a hydraulic pressure control. FIG. 3 is a sectional view showing the structure of the unit, FIG. 3 is a sectional view showing the structure of the hydraulic pressure transmitting means, and FIG. 4 is a sectional view of the master cylinder and the fail-safe valve.

First, in FIG. 1, this vehicle brake fluid pressure control device includes a master cylinder 2 for outputting a brake fluid pressure in response to a depression operation of a brake pedal 1, and a brake pedal 1.
Load cell 3 as an operation force detector for detecting the stepping operation force of the vehicle, a hydraulic pressure supply source 4, a hydraulic pressure control valve 12 capable of adjusting and outputting the output hydraulic pressure of the hydraulic pressure supply source 4, and the hydraulic pressure. Control valve 1
2, a linear solenoid 13 as an electric actuator for actuating 2, a left front wheel brake B _FL mounted on the left front wheel as a drive wheel, and a hydraulic pressure transmission means 14 _FL interposed between the hydraulic pressure control valve 12 and a drive wheel. Front right wheel brake B _FR mounted on the right front wheel as a hydraulic pressure transmission means and hydraulic pressure transmission means 14 _FR interposed between the hydraulic pressure control valve 12, and left and right rear wheels respectively mounted on the left and right rear wheels. Rear wheel brake B
Control consisting of a single hydraulic pressure transmission means 14 _R interposed between _RL , B _RR and the hydraulic pressure control valve 12, and a computer for controlling the operation of the linear solenoid 13 according to the detection value of the load cell 3. And means 6.

The hydraulic pressure supply source 4 includes a hydraulic pump 8 for pumping hydraulic fluid from a reservoir 7, an accumulator 9 connected to the hydraulic pump 8, and a pressure switch for controlling the operation of the hydraulic pump 8. And 10.

In FIG. 2, the hydraulic control valve 12 comprises a housing 15 and a spool 16 slidably fitted therein. The housing 15 is a cylindrical valve housing 1.
7 is fitted and fixed to a stepped bottomed cylindrical cover 18.

The housing 15 has an input port 20 communicating with an input passage 50 connectable to the hydraulic pressure supply source 4, and an output passage 1.
The output port 21 leading to 9 and the first release port 22 ₁ leading to the reservoir 7 via the release passage 23 are directed from the front side to the rear side (from the right side to the left side in FIG. 2). It is provided at intervals. The spool 16 is the cover 1
A spring chamber 27 is formed between the closed end of the valve housing 8, that is, the front end of the housing 15, and is slidably fitted to the valve housing 17, and the spring chamber 27 is connected to the second release port 22 _2.
Via the open path 23. Moreover, the spool 1
On the outer surface of 6, a first annular recess 28 that can communicate with the input port 20 and a second annular recess 28 that can communicate with the output port 21 at all times and can communicate the output port 21 with the first release port 22 ₁ .
The annular recess 29 is provided with a space in the axial direction.

A sliding hole 30 is formed in the front half of the spool 16.
A reaction piston 32 forming a reaction chamber 31 between the sliding hole 30 and the rear closed end of the sliding hole 30 is slidably fitted in the sliding hole 30. . Moreover, the first annular concave portion 28 and the second annular concave portion 29 communicate with each other via the reaction force chamber 31.

A cap 33 is fitted to the front end portion of the reaction force piston 32 protruding from the front end of the spool 16.
A retaining ring 34 is fitted on the inner surface of the front end of the valve housing 17, and a retainer 44 that can receive the cap 33 is locked to the retaining ring 34. Moreover, the return spring 35 is contracted between the retainer 44 and the cap 33. Therefore, the spool 16 is urged in the backward direction by the return spring 35 in the state where the hydraulic force is not acting on the reaction force chamber 31, but the hydraulic force acts on the reaction force chamber 31 to cause the reaction force piston 32 to move. In the state in which the cap 33 is moved forward until it comes into contact with the retainer 44, the hydraulic pressure in the reaction force chamber 31, that is, the hydraulic pressure in the output port 21, urges it in the backward direction.
On the other hand, since the thrust in the forward direction acts on the spool 16 from the linear solenoid 13, the spool 16 moves in the front-rear direction so that those forces are balanced.
The spool 16 closes the input port 20 and the second
The retracted position in which the output port 21 and the first release port 22 ₁ communicate with each other via the annular recess 29, and the input port 20.
By communicating with the first annular recess 28, the output port 21 communicates with the input port 20 and moves in the housing 15 between the forward position where the output port 21 is blocked from the first release port 22 ₁ .

The linear solenoid 13 is a hydraulic pressure control valve 12.
The valve housing 1 in the housing 15 is coaxially connected to the rear end of the housing 15 in the housing 15.
7, the fixed core 36 screwed into the rear end opening of the cover 18 until it comes into contact with the rear end of the cover 18, the yoke 37 arranged to face the fixed core 36, and the movable core arranged between the fixed core 36 and the yoke 37. A core 38, a drive rod 39 integrally and coaxially connected to the movable core 38 and penetrating the fixed core 36 in a movable manner, and an electromagnetic force for attracting the movable core 38 to the fixed core 36 side. And a coil 40.

A cylindrical protrusion 36 for guiding the movable core 38 in the axial direction is provided on the fixed core 36 and the yoke 37.
a, 37a are coaxially opposed and protruded at an interval from each other, and the coil 40 is arranged so as to surround the protruding portions 36a, 37a. Further, the fixed core 36 and the yoke 37 are connected to each other by the cylindrical body 41 surrounding the coil 40.

The rear end of the drive rod 39 is supported by the yoke 37 via a bearing 42 so as to be movable in the axial direction.
A bearing 43 that guides the axial movement of the drive rod 39 is provided between the shaft 9 and the fixed core 36.

The tip of the drive rod 39 is coaxially brought into contact with the rear end of the spool 16 of the hydraulic control valve 12, and the coil 40 of the movable core 38 integrated with the drive rod 39 is in a demagnetized state. At times, the spring force of the return spring 35 provided between the front end of the spool 16 and the retainer 44 urges the fixed core 36 away from the fixed core 36.

The linear solenoid 13 as described above exerts a thrust in the forward direction according to the amount of electric power applied to the coil 40, and when the coil 40 is excited, the thrust in the forward direction from the drive rod 39 to the spool 16 is generated. Is given.

When a forward thrust is applied to the spool 16 from the linear solenoid 13, the spool 16
Cuts off the first release port 22 ₁ from the second annular groove 29, that is, the reaction force chamber 31, and then advances to a position where the input port 20 communicates with the first annular groove 28, that is, the reaction force chamber 31.
The reaction force piston 32 moves forward with respect to the spool 16 in response to the hydraulic pressure from the hydraulic pressure supply source 4 in the reaction force chamber 31, whereby the cap 33 at the front end of the reaction force piston 32 is retained by the retainer 4.
Received at 4. In this manner, when the reaction force piston 32 is received by the retainer 44, the spool 16 according to the magnitude relation between the thrust force in the forward direction given by the linear solenoid 13 and the force in the backward direction due to the hydraulic pressure of the reaction force chamber 31. Moves in the axial direction, and the hydraulic pressure from the input passage 50 acts on the output port 21, or the hydraulic pressure at the output port 21 is released, so that the hydraulic pressure from the input passage 50 is transferred to the linear solenoid 13. Output port 2 controlled proportionally to the exciting current
It will be output from 1.

Moreover, the exciting current of the linear solenoid 13 is controlled by the control means 6, and the control means 6 controls the exciting current amount according to the detected value of the load cell 3 during the normal brake operation.

The hydraulic pressure transmitting means 14 _FL , 14 _FR and 14 _R are
Since they have basically the same configuration, only the structure of the portion related to the hydraulic pressure transmitting means 14 _FL will be described in detail below, and the other hydraulic pressure transmitting means 14 _FR and 14 _R will be denoted by subscripts. Only " _FR " and " _R " are shown for illustration.

In FIG. 3, the hydraulic pressure transmitting means 14 _FL has a cylindrical casing 45 having both ends closed, and one end having the input chamber 4
6, a free piston 48 slidably fitted to the casing 45 with the other end facing the output chamber 47.
And a spring 49 housed in the output chamber 47 to exert a spring force for urging the free piston 48 toward the input chamber 46.

To the input chamber 46, an output passage 19 leading to the output port 21 of the hydraulic pressure control valve 12 is connected via a _normally open solenoid valve 24 _FL for controlling the hydraulic pressure of the input chamber and a release passage 23.
There are connected via the input chamber fluid pressure control normally closed electromagnetic valve 25 _FL. The output chamber 47 is connected to the left front wheel brake device _BFL .

The hydraulic pressure transmission means 14 _FL is a solenoid valve 24.
_{When FL} , 25 _FL are demagnetized, the free piston 48 moves to the output chamber 47 side according to the hydraulic pressure output from the hydraulic pressure control valve 12, so that the output hydraulic pressure of the hydraulic pressure control valve 12 is changed. A corresponding hydraulic pressure is applied from the output chamber 47 to the left front wheel braking device B _FL . Moreover, the hydraulic pressure transmission means 14 _FL serves to isolate the hydraulic fluid on the left front wheel brake device B _FL side from the hydraulic fluid on the hydraulic pressure control valve 12 side.

An annular recess 51 is provided on the outer surface of the free piston 48, and a pair of cup seals 52, 53 are mounted on the outer surface of the free piston 48 so that the annular recess 51 is sandwiched between them. Thus, the annular recess 51 is communicated with the release passage 23, and the cup seal 52 on the output chamber 47 side allows replenishment of the working fluid from the annular recess 51 to the output chamber 47 when the hydraulic pressure in the output chamber 47 decreases. .

The input chamber 46 of the hydraulic pressure transmission means 14 _FR is connected to the output passage 19 via the normally open solenoid valve 24 _FR for controlling the hydraulic pressure of the input chamber.
Normally closed solenoid valve 2 for input chamber hydraulic pressure control
5 is connected to the reservoir 7 through the _{FR
The FR} output chamber 47 is connected to the right rear wheel brake B _FR . Further, the input chamber 46 of the hydraulic pressure transmission means 14 _R is connected to the output path 19 via the input chamber hydraulic pressure control normally open solenoid valve 24 _R, and the input chamber hydraulic pressure control normally closed solenoid valve 25 _R is connected. Is connected to the reservoir 7 via the output chamber 4 of the hydraulic pressure transmission means 14 _R.
7 is connected to both rear wheel brakes B _RL and B _RR via a proportional pressure reducing valve 26 (see FIG. 1).

Referring again to FIG. 1, the output of the master cylinder 2
The auxiliary output hydraulic path 56 is connected to the force port 55.
In the middle of this auxiliary output hydraulic line 56, the master cylinder
The output fluid pressure of the damper 2 is absorbed and the reaction force is applied to the brake pedal 1.
And the stroke accumulator 57 that gives the stroke
Connected. Moreover, the auxiliary output hydraulic passage 56 is provided with the cut valve 5
8_FLLeft front wheel brake B via_FLCut valve 58_FRTo
Right front wheel brake B through _FRCut valve 58_RAnd ratio
Example Left and right rear wheel brake B through pressure reducing valve 26_RL, B_RRTo
Connected respectively.

As shown in FIG. 3, a cut valve 58 is provided between the auxiliary output hydraulic pressure passage 56 and the output chamber 47 of the hydraulic pressure transmission means 14 _FL.
FL is interposed. The cut valve 58 _FL is a hydraulic pressure control valve 1
It is an open / close valve that closes when the hydraulic pressure in the pilot hydraulic pressure passage 59 branched from the output passage 19 leading to the second output port 21 becomes large. Therefore, the normal hydraulic pressure is output from the hydraulic pressure supply source 4, and the hydraulic pressure control valve 1 is operated according to the brake operation.
When the brake fluid pressure acts on the left front wheel brake B _FL from 2, the cut valve 58 _FL is closed, but the fluid pressure supply source 4 fails for some reason and the brake fluid pressure cannot be obtained from the fluid pressure control valve 12. Occasionally, the cut valve 58 _FL opens so that the output hydraulic pressure from the master cylinder 2 corresponding to the brake operation is output from the auxiliary output hydraulic pressure passage 56 to the output chamber 47 of the hydraulic pressure transmission means 14 _FL.
After that, it will act on the left front wheel brake B _FL .

The input passage 50 communicating with the input port 20 of the hydraulic pressure control valve 12 is configured so as to be opened according to the brake operation of the brake pedal 1, and via a fail safe valve 61 attached to the master cylinder 2. Is connected to the hydraulic pressure supply source 4, and a normally closed solenoid valve 60 for traction control is provided between the input path 50 and the hydraulic pressure supply source 4.

4, in the cylinder body 62 of the master cylinder 2, a mounting hole 63 on the front side thereof and a cylinder hole 64 on the rear side thereof have a flange portion 65 extending inward in the radial direction between them. It is installed coaxially.

The fail-safe valve 61 includes a cylindrical valve housing 66 fitted and fixed in the mounting hole 63, and a spool-shaped valve body 67 slidably fitted in the valve housing 66. Prepare The valve housing 66 is fitted into the mounting hole 63 such that the rear end of the valve housing 66 comes into contact with the flange 65. The load cell 3 as an operation force detector is screwed into the front end opening of the mounting hole 63, and the valve housing 66 is sandwiched between the load cell 3 and the collar portion 65.
In addition, a pressing piston 70 that forms a liquid chamber 69 between the valve housing 67 and the valve body 67 is slidably fitted in the front portion of the valve housing 66, and between the pressing piston 70 and the valve body 67. A spring 71 that exerts a spring force in a direction to separate the two 70, 67 from each other is contracted. Then the pressing piston 70
Is always in contact with the central portion of the load cell 3, that is, the load detection portion 3a.

In the valve housing 66, an output hole 73 communicating with the input path 50 communicating with the input port 20 of the hydraulic pressure control valve 12 and an input hole 74 communicating with the hydraulic pressure supply source 4 are axially spaced. An annular recess 75 is provided on the outer surface of the valve body 67. Thus, when the valve body 67 is at the retracted limit position as shown in FIG.
To the valve body 67, but is disconnected from the output hole 73.
When is moved forward from the retracted limit position, the annular recess 75 communicates between the input hole 74 and the output hole 73.

The master cylinder 2 has a fail-safe valve 6
1 between the interlocking piston 76 coaxially abutting on the rear end of the valve element 67 and slidably fitted in the cylinder hole 64, and the interlocking piston 76 interlocked with and connected to the brake pedal 1 and the back surface of the interlocking piston 76. A working piston 78 slidably fitted in the cylinder hole 64 with the front surface facing the pressure chamber 77 defined by the pressure sensor 77, and a spring 79 contracted between the pistons 76, 78.

A restricting member 80 for restricting the retreat limit of the operating piston 78 is fixed to the rear end opening of the cylinder hole 64, and a piston rod 81 which movably penetrates the restricting member 80 in a fluid-tight manner operates. It is connected coaxially to the piston 78. On the other hand, a push rod 82 is connected to the brake pedal 1, and a front end of the push rod 82 is swingably connected to the piston rod 81. Therefore, in response to the depression operation of the brake pedal 1, the working piston 78 moves forward in the direction of reducing the volume of the pressure chamber 77.

A valve box 83 is fixed to the front end of the operating piston 78, and a cylindrical retainer 84 having a bottom is brought into contact with the back surface of the interlocking piston 76, and a spring 79 is contracted between the valve box 83 and the retainer 84. To be done. Moreover, the rear end of the rod 85 penetrating the retainer 84 movably is fixed to the valve box 83 so that the retracting limit position with respect to the interlocking piston 76 is regulated by the retainer 84. The maximum spacing between 78 will be regulated.

The cylinder body 62 is provided with an output port 55 which is in constant communication with the pressure chamber 77.
5 is connected to an auxiliary output hydraulic pressure passage 56. Working piston 7
8 and the regulating member 80 define an annular replenishing liquid chamber 86, and the replenishing liquid chamber 86 communicates with the reservoir 7. A cup seal 87 is attached to the outer periphery of the working piston 78 at a position forward of the replenishing liquid chamber 86, and the working piston 78 has a communication hole 88 for communicating the replenishing liquid chamber 86 with the back surface of the cup seal 87. Is drilled.

A central relief valve 90 is provided between the replenishing liquid chamber 86 and the pressure chamber 77. This relief valve 90
Is a valve hole 91 that is provided coaxially with the working piston 78 through the replenishing liquid chamber 86 and that opens at the front end of the working piston 78 in the valve box 83, and the front end opening of the valve hole 91 can be closed. The valve body 9 housed in the valve box 83 so as to be movable back and forth.
2, a valve spring 93 that is stored in the valve casing 83 by exerting a spring force that biases the valve body 92 rearward, that is, in the closing direction of the valve hole 91, and the valve body 92 when the working piston 78 is in the backward limit. Is held at the forward position against the spring biasing force of the valve spring 93, but when the actuating piston 78 is advanced, the valve spring 93 is provided with a valve opening rod 94 that allows the valve body 92 to retract or close.

The operating piston 78 includes the operating piston 7
8 is provided with a long hole 95 which is long in the axial direction, and both ends of the long hole 95 communicate with the replenishing liquid chamber 86. The valve opening rod 94 has a long hole 95.
Both ends of the valve opening rod 94 are supported by a support ring 96 that surrounds the piston rod 81. Moreover, although not clearly shown, a spring is contracted between the working piston 78 and the support ring 96, and the support ring 96 is urged by the spring force in a direction to be received by the restriction member 80.

The valve hole 91 includes an elongated hole 95 and an operating piston 78.
Of the rod 9 that is provided continuously to the front end of the rod 9 and is integrally connected to the valve body 92 and inserted into the valve hole 91.
The rear end of 7 contacts the valve opening rod 94.

According to such a relief valve 90, when the operating piston 78 is in the retracted limit, the rod 97 is pushed by the valve opening rod 94 so that the valve body 92 is in the position to open the valve hole 91. By opening the valve, the replenishing liquid from the replenishing liquid chamber 86 can be replenished to the pressure chamber 77. Also the working piston 78
Is moved from the backward limit, the valve opening rod 94 moves relative to the actuating piston 78 so as to be positioned rearward in the elongated hole 95, so that the valve element 92 moves the valve hole 91 by the spring force of the valve spring 93. After moving to the closed position, the replenishing liquid chamber 86 and the pressure chamber 77 are shut off from each other.

A liquid chamber 98 formed in the cylinder body 62 between the interlocking piston 76 and the fail-safe valve 61 is also communicated with the reservoir 7.
The valve body 67 is coaxially formed with a communication hole 99 communicating with the liquid chamber 69 facing the front end thereof, and the communication hole 10 for communicating the communication hole 99 with the liquid chamber 98 is provided at the tip of the interlocking piston 76.
0 is drilled.

Next, the operation of this embodiment will be described.
Normally, the normally open solenoid valve 24 for controlling the input chamber hydraulic pressure is_FL,
24_FR, 24_R, Normally closed solenoid valve for input chamber hydraulic pressure control 2
5_FL, 25 _FR, 25_R, And for traction control
The closed solenoid valve 60 is demagnetized. In such a state
When you press the rake pedal 1 to operate the brake,
The working piston 78 of the star cylinder 2 advances and the spring 79
The interlocking piston 76 also moves forward via. This makes it
The valve body 67 of the ilsafe valve 61 moves forward from the backward limit to input
The hole 74 and the output hole 73 communicate with each other. At this time, the valve body 6
In response to the forward movement of 7, the pressing piston 70 is
The load detection unit 3a of the load cell 3 is pressed. This road
According to the detection signal of the cell 3, the control means 6 is a linear solenoid.
The coil 40 of the battery 13 is charged according to the detected value of the load cell 3.
Excited by force, the output port 21 of the hydraulic control valve 12
The hydraulic pressure corresponding to the operating force is output and each wheel brake
B_FL, B_FR, B_RL, B_RRBrake fluid pressure will act on
It

By depressing the brake pedal 1,
The hydraulic pressure generated in the pressure chamber 77 of the master cylinder 2 is output as
It acts on the auxiliary output hydraulic line 56 from the port 55, but
Depending on the hydraulic pressure output from the output port 21 of the control valve 12,
Valve 58_FL, 58_FR, 58 _RIs closed
The hydraulic pressure from the master cylinder 2 is applied to each wheel brake.
B_FL, B_FR, B_RL, B_RRDoes not act on.

When the wheels are likely to be locked during such braking, the input chamber hydraulic pressure control normally open solenoid valves 24 _FL , 24 _FR and 24 _R , and the input chamber hydraulic pressure control normally closed type solenoid valves. By controlling the excitation of the solenoid valves 25 _FL , 25 _FR , and 25 _R corresponding to the wheel that is about to lock by the control means 6, the braking fluid pressure of the wheel brake that is about to enter the locked state is reduced. This prevents the locked state from being entered.

It is assumed that the drive wheels, that is, the front wheels, excessively slip while the vehicle is running in the non-brake operation state. At this time, the normally closed solenoid valve 6 for traction control
0 is excited to open the valve, and the input chamber hydraulic pressure control normally open solenoid valve 24 _R corresponding to both rear wheels is excited to close the valve. By exciting the linear solenoid 13 in this state, hydraulic pressure is output from the hydraulic pressure control valve 12, the cut valves 58 _FL and 58 _FR are closed, and hydraulic pressure is applied to both front wheel brakes B _FL and B _FR. Even if the brake pedal 1 is not actuated, the hydraulic pressure of the front wheel brakes B _FL and B _FR is increased, and the braking force acts on the front wheels to reduce the driving force, and excessive slip can be eliminated. Becomes

Further, it is assumed that the hydraulic pressure of the hydraulic pressure supply source 4 is abnormally lowered during the brake operation. In this case, the hydraulic pressure output from the hydraulic pressure control valve 12 is impossible, but each cut valve 5
Since 8 _FL , 58 _FR and 58 _R are open, the hydraulic pressure from the master cylinder 2 is applied to each wheel brake B _FL , B _FR ,
It is possible to obtain a braking force by acting on B _RL and B _RR .

Further, assume that the linear solenoid 13 is erroneously operated due to a failure of the electric system including the control means 6 and the linear solenoid 13 during non-brake operation.
In this case, the fail-safe valve 61 is in a closed state, and the hydraulic pressure supply source 4 and the hydraulic pressure control valve 12 are shut off.
Therefore, even if the spool 16 of the fluid pressure control valve 12 is activated by the operation of the linear solenoid 13, the braking fluid pressure does not act on the wheel brakes B _FL , B _FR , B _RL , B _RR .

In this way, during non-brake operation, the fail-safe valve 61 is closed to disconnect the hydraulic pressure supply source 4 and the hydraulic pressure control valve 12 from each other, so that the wheel brakes B _FL and B _FL due to the electric system failure. _It is possible to reliably prevent the malfunction of _FR , B _RL , and B _RR .

By the way, there is a possibility that the fail-safe valve 61 may be hydraulically locked because the high-pressure hydraulic pressure from the hydraulic pressure supply source 4 is constantly acting on the outer circumference of the valve body 67 of the fail-safe valve 61. However, the valve body 67 is interlocked with and linked to the brake pedal 1,
Since the stepping operation force of the valve acts on the valve body 67, even if the fail-safe valve 61 is hydraulically locked, the valve body 67 can be reliably operated and the fail-safe valve 61 can be opened. It is possible to prevent the rise of pressure from being delayed.

Further, the fail-safe valve 61 and the load cell 3 are incorporated in the front part of the cylinder body 62 in the master cylinder 2, and the structure is compact.

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 linear solenoid 13 and the hydraulic pressure control valve 12 may be provided for each of a plurality of wheel brake groups. In that case, the hydraulic pressure control valve 12 has a high hydraulic pressure from the hydraulic pressure supply source 4. The hydraulic fluid leaks from the plurality of hydraulic pressure control valves 12 when the hydraulic pressure control valve 12 is continuously operated. However, the single fail-safe valve 61 shuts off the hydraulic pressure supply source 4 from each hydraulic pressure control valve 12. By switching the communication, the leakage of the hydraulic fluid can be minimized, and accordingly, the number of times the hydraulic pump 8 is operated in the hydraulic pressure supply source 4 is reduced as much as possible to improve reliability. be able to. If traction control is unnecessary, the normally-closed solenoid valve 60 for traction control may be omitted.

[0056]

As described above, according to the present invention, between the hydraulic pressure supply source and the hydraulic pressure control valve, the state in which the hydraulic pressure supply source and the hydraulic pressure control valve are disconnected when the brake pedal is not pressed, and When the brake pedal is pressed, the state of communicating between the hydraulic pressure supply source and the hydraulic pressure control valve is linked to the brake pedal.
Since a fail-safe valve that can be switched according to the movement of the connected valve element is installed, the failure of the electric actuator due to the fail-safe valve being closed during normal non-brake operation without operating the brake pedal. Therefore, the hydraulic pressure is not output from the hydraulic pressure control valve, and therefore the braking hydraulic pressure does not act on the wheel brakes. In addition, since the valve body of the fail-safe valve is linked and connected to the brake pedal, the fail-safe valve can be operated reliably even if hydraulic pressure is locked by the fail-safe valve, which is an expensive electromagnetic on-off valve. It is possible to prevent a delay in rising of the braking hydraulic pressure from occurring with a low-cost configuration that does not use the.

[Brief description of drawings]

FIG. 1 is an overall hydraulic circuit diagram.

FIG. 2 is a cross-sectional view showing configurations of a linear solenoid and a hydraulic control valve.

FIG. 3 is a cross-sectional view illustrating a configuration of a hydraulic pressure transmitting unit.

FIG. 4 is a sectional view of a master cylinder and a fail-safe valve.

[Explanation of symbols]

1 ... Brake pedal 3 ... Load cell as operating force detector 4 ... Hydraulic pressure supply source 6 ... Control means 12 ... Hydraulic pressure control valve 13 ... Linear solenoid as electric actuator 61 ... Failsafe valve 67 ... Valve _BFL , _BFR , _BRL , _BRR ... Wheel brake

Claims (1)

[Claims] 1. An operating force detector (3) for detecting an operating force of a brake pedal (1), a hydraulic pressure supply source (4), an electric actuator (13), and the hydraulic pressure supply source (4). Of the wheel brakes (B _FL , B _FR , B _RL ) by adjusting the output hydraulic pressure of the wheel to a hydraulic pressure corresponding to the operation of the electric actuator (13).
B _RR ) a hydraulic control valve (12) and a control means (6) for controlling the operation of the electric actuator (13) according to the detection value of the operating force detector (3). In the braking hydraulic pressure control device for use, between the hydraulic pressure supply source (4) and the hydraulic pressure control valve (12), when the brake pedal (1) is not pressed, the hydraulic pressure supply source (4) and the hydraulic pressure control valve ( 1
2) The state in which the two are shut off and the brake pedal (1) is pressed to operate the hydraulic pressure source (4) and the hydraulic control valve (1).
2) The state of communicating between the two is linked to the brake pedal (1),
A braking hydraulic pressure control device for a vehicle, wherein a fail-safe valve (61) that can be switched according to the movement of a valve body (67) to be connected is provided.