JPH06312658A - Hydraulic brake device - Google Patents

Abstract

PURPOSE:To provide improved reliability and size reduction of a hydraulic control valve in a hydraulic brake device which controls the hydraulic pressure of a hydraulic pressure source electrically for feeding it to a wheel cylinder. CONSTITUTION:Hydraulic control valves 50-56 are mounted between a master cylinder 12 and wheel cylinders 22, 24, 34, 36, the hydraulic pressure of an accumulator 82 is controlled according to master cylinder hydraulic pressure, and the hydraulic pressure is electrically-controlled by a force motor. When master cylinder hydraulic pressure exceeds a prescribed value, cut valves 190, 250 are closed, the hydraulic pressure control force of a control piston which receives the master cylinder hydraulic pressure is restricted, so it is possible to make the diameter of the control piston without increasing the size of the force motor, and attain excellent output hysteresis characteristics. If hydraulic pressure is not fed to the front wheel cylinders 22, 24, the cut valve 250 is not closed, and large rear wheel braking force is attained. It is thus possible to avoid reduction of braking force of the whole vehicle with high efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic brake device in which the hydraulic pressure of a wheel cylinder is electrically controlled, and more particularly to improvement of reliability.

[0002]

2. Description of the Related Art In a hydraulic brake device, the hydraulic pressure of a hydraulic pressure source is electrically controlled to a height according to the operating force of a brake operating member such as a brake pedal and a brake operating lever to suppress wheel rotation. There is a device that supplies to the wheel cylinder of the brake. An example is a hydraulic brake device having a spool-type electromagnetic hydraulic pressure control valve described in JP-A-63-20256.

The spool type electromagnetic hydraulic pressure control valve is a control force which is electrically controlled by exciting a coil of a force motor on a spool which is slidably and substantially fluid-tightly fitted in a valve hole in a housing. And a reaction force that is in the opposite direction to the control force and whose magnitude is proportional to the output hydraulic pressure of the spool type electromagnetic hydraulic pressure control valve itself, and the hydraulic pressure of the hydraulic pressure source is proportional to the exciting current of the coil. It is a control valve that controls. The housing is provided with a high pressure port connected to the hydraulic pressure source, a low pressure port connected to the reservoir, and a control pressure port connected to the wheel cylinder. Control force is applied to the spool and the control pressure port is applied to the high pressure port. It is operated in the direction of communication. Also,
The reaction force is made to act on the spool so that the control pressure port communicates with the low pressure port based on the hydraulic pressure of the control pressure port.
The spool moves to a position where the control force and the reaction force are balanced with each other, and the hydraulic pressure of the hydraulic pressure source is controlled to a height according to the exciting current of the coil. Then, the depressing force of the brake pedal (referred to as pedal depressing force) is detected by the depressing force sensor, and the deceleration of the vehicle is detected by the deceleration sensor to obtain the deceleration of the hydraulic pressure source according to the pedaling force. The exciting current of the coil is determined in order to control the height to be controlled. This control will be referred to as braking effect control. Further, the hydraulic pressure of the wheel cylinder may be detected by a hydraulic pressure sensor, and the exciting current may be controlled so that the control pressure has a height at which deceleration corresponding to the pedal effort is obtained.

[0004]

However, when electrically controlling the hydraulic pressure of the wheel cylinder based on the output signal of the sensor such as the pedaling force sensor, the deceleration sensor, the hydraulic pressure sensor, etc., the sensor may fail. For example, the wheel cylinder hydraulic pressure becomes excessively large or excessively small with respect to the operating force of the brake operating member, and proper braking cannot be performed.
In each of the first and second aspects of the invention, the hydraulic pressure of the hydraulic pressure source can be controlled to a height according to the operating force of the brake operating member by the hydraulic pressure control valve without using an electrical sensor. The object is to provide a pressure brake device.

[0005]

In order to solve the above-mentioned problems, a hydraulic braking device according to the invention of claim 1
(A) A master cylinder that generates hydraulic pressure in the pressurizing chamber according to the operating force of the brake operating member, and (B) a brake that operates by hydraulic pressure being supplied to the wheel cylinders to suppress wheel rotation. , (C) a reservoir, (D) a hydraulic pressure source other than the master cylinder, and (E) a hydraulic pressure source provided between the master cylinder, the wheel cylinder, the reservoir, and the hydraulic pressure source. Supply to the wheel cylinder by applying a hydraulic pressure control valve that controls the height according to the hydraulic pressure of the master cylinder and supplies it to the wheel cylinder, and (F) an electrically controlled force to the hydraulic pressure control valve. Is provided between the (G) master cylinder and the hydraulic control valve, which is provided between the electric hydraulic pressure changing device for changing the hydraulic pressure to be applied and the hydraulic pressure in the pressurizing chamber exceeds the set value. Reduces the rising gradient of hydraulic pressure supplied to the pressure control valve Configured to include a cell pressure increase gradient reducer. A hydraulic brake device according to a second aspect of the present invention includes: (a) a master cylinder that has a plurality of pressurizing chambers and that generates a hydraulic pressure in each pressurizing chamber according to the operating force of a brake operating member; ) A plurality of brake systems that constitute a plurality of brake systems together with a plurality of pressurizing chambers, each of which is activated by hydraulic pressure being supplied to a wheel cylinder to suppress the rotation of each wheel, and (c) a reservoir. And (d)
Between the hydraulic pressure source different from the master cylinder, (e) the first pressurizing chamber and the first wheel cylinder of the first brake system, which is one of the plurality of brake systems, the reservoir, and the hydraulic pressure source. A hydraulic pressure control valve provided to control the hydraulic pressure of the hydraulic pressure source to a height corresponding to the hydraulic pressure of the first pressurizing chamber and supply the hydraulic pressure to the first wheel cylinder; and (f) an electrically controlled force. Between the electric hydraulic pressure changing device for changing the hydraulic pressure supplied to the first wheel cylinder by applying the hydraulic pressure control valve, (g) the hydraulic pressure control valve, and the first pressurizing chamber. When the hydraulic pressure supplied to the hydraulic pressure control valve exceeds the set pressure, a hydraulic pressure rising gradient reducing device that reduces the rising gradient of the hydraulic pressure supplied from the first pressurizing chamber to the hydraulic pressure control valve is provided. , (H) to a second wheel cylinder of a second brake system which is another one of the plurality of brake systems When brake fluid is no longer performed, configured to include a suppressing pressure rise gradient decreasing function suppressing means the hydraulic pressure increase gradient decreasing function of the fluid pressure increase gradient reducer.

[0006]

In the hydraulic brake device according to the first aspect of the present invention, when the brake operating member is operated, hydraulic pressure corresponding to the operating force is generated in the pressurizing chamber of the master cylinder, and the hydraulic control valve is operated. As a result, the hydraulic pressure of the hydraulic pressure source is controlled to a height corresponding to the hydraulic pressure of the master cylinder, that is, a height corresponding to the operating force of the brake operating member, and is supplied to the wheel cylinder to suppress the rotation of the wheels. The height of the control pressure obtained by the hydraulic pressure control valve is determined according to the hydraulic pressure of the master cylinder.The hydraulic pressure control valve is a pilot type hydraulic control valve, and the master cylinder has a pilot pressure control valve. Will be a means of supplying. Since the hydraulic pressure controlled by the hydraulic pressure control valve and supplied to the wheel cylinders can be changed by the electric hydraulic pressure changing device,
The hydraulic pressure of the wheel cylinder can be controlled to a height that does not correspond to the operating force of the brake operating member on a one-to-one basis, and antilock control, braking effect control, acceleration slip control, etc. can be performed. In the case of acceleration slip control,
Since the brake operating member is not operated and the hydraulic pressure control valve does not control the hydraulic pressure, the electric hydraulic pressure changing device controls the hydraulic pressure of the hydraulic pressure source to supply the hydraulic pressure to the wheel cylinders. Further, when the hydraulic pressure in the pressurizing chamber of the master cylinder exceeds the set value, the rising gradient of the hydraulic pressure supplied from the pressurizing chamber to the hydraulic pressure control valve is reduced. "Reducing the ascending slope" includes not only the case where the ascending slope is reduced, but also the case where the ascending slope is made zero. The increase in the hydraulic pressure supplied to the hydraulic pressure control valve is suppressed to a low level or is prevented from increasing. In any case, the hydraulic pressure supplied from the hydraulic pressure control valve to the wheel cylinder is the hydraulic pressure increase gradient. Is kept low compared to the case where is not reduced.

In the hydraulic brake device according to the invention of claim 2, the same action as the hydraulic brake device according to the invention of claim 1 can be obtained in the first brake system, and, in addition, the second wheel in the second brake system. When the supply of the brake fluid to the cylinder is stopped, the decrease in the hydraulic pressure increase gradient of the hydraulic pressure control valve in the first brake system is suppressed. The degree of reduction is reduced or is not reduced. Therefore, in the first brake system, a higher hydraulic pressure is supplied from the hydraulic control valve to the wheel cylinder than in the case where the brake fluid is supplied in the second brake system. It should be noted that "when the brake fluid is no longer supplied to the second wheel cylinder" means at least when the brake fluid is not supplied to the second wheel cylinder at all. Is not supplied at all, but is less than the case where it is normally supplied, and does not exclude the case where the brake fluid is not normally supplied to the second wheel cylinder.

[0008]

As described above, according to the first aspect of the invention, the hydraulic pressure of the hydraulic pressure source is basically controlled without using electrical means, and the electrical control is added to it. Therefore, even if an abnormality should occur in the electric control means, the influence thereof is small, and a highly reliable hydraulic brake device can be obtained. Moreover, when the hydraulic pressure in the pressurizing chamber of the master cylinder exceeds the set value, the rising gradient of the hydraulic pressure supplied to the hydraulic pressure control valve is reduced. As described above, the hysteresis of the hydraulic pressure supplied from the hydraulic control valve to the wheel cylinder can be reduced without increasing the size of the electric hydraulic pressure changing device, and a hydraulic brake device with excellent responsiveness can be provided. Obtainable. According to the invention of claim 2, claim 1
The effect of the invention can be obtained, and further, since the function of the hydraulic pressure increase gradient reducing device is suppressed when the supply of the brake fluid to the second wheel cylinder is not normally performed, the first brake system A braking force larger than that when the second brake system is normal can be obtained, and a decrease in the braking force of the vehicle can be suppressed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the invention of claim 2 will be described below in detail with reference to the drawings. In FIG. 1, 10 is a brake pedal as a brake operating member. By depressing the brake pedal 10, hydraulic pressure is generated in each of the two pressurizing chambers 13 and 15 of the master cylinder 12. One of the pressurizing chambers 13 includes a liquid passage 14 and a liquid passage 16 branched from the liquid passage 14, and front wheel cylinders 22 of a brake provided on left and right front wheels 18 and 20, respectively.
It is connected to 24. The other pressurizing chamber 15 has a liquid passage 26 and a liquid passage 28 branched from the liquid passage 26.
Are connected to rear wheel cylinders 34 and 36 of brakes provided on the left and right rear wheels 30 and 32, respectively.

In this embodiment, the pressurizing chamber 15 and the rear wheel cylinders 34, 36 are the first brake system 38.
The pressure chamber 15 is the first pressure chamber, and the rear wheel cylinders 34, 36 are the first wheel cylinders. Also,
Pressurization chamber 13 and front wheel cylinders 22, 24
Constitutes the second brake system 40, the pressurizing chamber 13 is the second pressurizing chamber, and the front wheel cylinders 22 and 24 are the second wheel cylinders. Hereinafter, the pressurizing chambers 13 and 15 will be referred to as the front pressurizing chamber 13 and the rear pressurizing chamber 15, respectively, and the hydraulic pressures generated in these pressurizing chambers 13 and 15 will be referred to as the front master cylinder hydraulic pressure and the rear pressurizing chamber, respectively. For master cylinder hydraulic pressure.

Liquid pressure control valves 50, 52, 54, 56 are provided in the liquid passages 14, 16, 26, 28, respectively, whereby the liquid passages 14, 16, 26, 28 are respectively provided in the liquids on the master cylinder side. Passages 14M, 16M, 26M,
28M and wheel cylinder side liquid passages 14W, 16W,
It is divided into 26W and 28W. Hydraulic control valve 50,
The configurations of 52, 54, and 56 are the same, and the hydraulic control valve 50 will be described as a representative.

As shown in FIG. 2, the hydraulic control valve 50 has a valve housing 57. Valve housing 57
Is integrally formed with the control force generation housing 59 of the control force generation device 58, and a bottomed valve hole 60 having a circular cross section is formed inside the valve housing 57.
In the control force generating housing 59, a large space 62 located on the opening end side of the valve hole 60, and a bottomed cylinder bore 6 opening on the opposite side of the space 62 to the side where the valve hole 60 opens.
4 are formed. The valve hole 60, the space 62 and the cylinder bore 64 are formed concentrically with each other.

A spool 66 is fitted in the valve hole 60 so as to be substantially liquid-tight and slidable. The spool 66 has a stepped shape, and a small diameter portion 72 is formed between the first large diameter portion 68 and the second large diameter portion 70. The small diameter portion 72 is formed in the valve hole 60 in the first and second large diameter portions 68 and 70. It is fitted. First and second large diameter part 6
The clearance between the outer peripheral surface of 8, 70 and the inner peripheral surface of the valve hole 60 is as small as 10 μm in diameter, and an intermetallic seal is formed between the outer peripheral surface and the inner peripheral surface.

Also inside the valve housing 57 is a valve hole 6
A pin hole 74 having a diameter smaller than 0 and a bottom is formed, and a reaction force piston 76 is fitted in a substantially liquid-tight and slidable manner to form an intermetallic seal, and a spring 78.
By this, it projects into the valve hole 60 and is urged in a direction to come into contact with the spool 66. The space between the bottom surface of the valve hole 60 and the spool 66 is connected to the reservoir 80 by the first low pressure port 79.

The valve housing 57 is further provided with a high pressure port 8 to which an accumulator 82 as a hydraulic pressure source is connected.
4, a second low pressure port 88 connected to the reservoir 80, and a control pressure port 90 connected to the front wheel cylinder 22 by the wheel cylinder side liquid passage 14W. The high pressure port 84 is connected to the accumulator 82 via the check valve 92, and the flow of the brake fluid from the accumulator 82 to the high pressure port 84 is allowed, but the reverse flow is blocked. . The brake fluid pumped up from the reservoir 80 by the pump 94 being driven by the motor 96 is stored in the accumulator 82.

The control pressure port 90 is communicated with an annular chamber 98 formed by the small diameter portion 72 of the spool 66 and the inner peripheral surface of the valve hole 60, and the high pressure port 84 is connected to the high pressure port 84.
It is communicated with an annular groove 100 formed in a portion on the bottom side of the control pressure port 90 of 0. The second low pressure port 88 is communicated with the annular groove 102 formed on the opening side of the valve hole 60 with respect to the control pressure port 90 of the valve hole 60.

Further, a liquid passage 104 branched from the control pressure port 90 is connected between the bottom surface of the pin hole 74 and the reaction force piston 76, and the reaction force piston 76 is connected to the control pressure port 90. Upon receiving the pressure, a reaction force based on the hydraulic pressure is generated, and the reaction force is applied to the spool 66 in a direction in which the communication between the high pressure port 84 and the control pressure port 90 is blocked. The reaction force piston 76 and the liquid passage 104 form a reaction force means.

The force motor 11 is provided in the space 62.
0 is set. The force motor 110 has a permanent magnet 112 and a moving coil 114. Space 6
An annular groove 118 is provided in the yoke 116 fixed in the second magnet 2, and a cylindrical portion 122 is formed in the center of the yoke 116. The permanent magnet 112 is fixed to the yoke 116 and constitutes the outer peripheral side surface of the annular groove 118. ing. The moving coil 114 is formed by winding a coil 128 around a holding member 126 made of a non-magnetic material. The holding member 126 has a bottomed cylindrical shape, a coil 128 is wound around the outer peripheral side of the cylindrical portion 130, and is slidably fitted to the cylindrical portion 122 via a bush 132 fixed to the inner peripheral surface. The bush 132 is made of a material having a small friction coefficient, and the movement of the moving coil 114 is guided by the cylindrical portion 122. Further, a projection 136 is provided on the bottom wall portion 134 of the holding member 126 so as to project toward the spool 66. The space 62 is connected to the reservoir 80 by a drain port 138 provided in the valve housing 57.

In the cylinder bore 64, a control piston 140 is fitted in a substantially liquid-tight and slidable manner to form an intermetallic seal. A control pressure chamber 142 is formed between the control piston 140 and the bottom surface of the cylinder bore 64, and the port 144 and the master cylinder side liquid passage 1 are formed.
It is connected to the front pressure chamber 13 by 4M.
A spring 146 is arranged in the control pressure chamber 142, and the control piston 140 is biased by the spring 146 so as to be projected into a through hole 148 penetrating on the center line of the yoke 116 and the control piston 1
The projecting portion 150 projectingly provided on the tip end surface of 40 is the holding member 1
It is abutted on the bottom wall portion 134 of 26. Through hole 14
8 is a reservoir 1 through a hole 152 formed in the bottom wall portion 134 of the holding member 126 and the drain port 138.
It is communicated with 80 and serves as an atmospheric pressure chamber.

The spool 66, the reaction force piston 76, the moving coil 114, and the control piston 140 are biased in opposite directions by springs 78 and 146 to move integrally, and the master cylinder hydraulic pressure is supplied to the control pressure chamber 142. Without the excitation current being supplied to the coil 128,
As shown in FIG. 2, the control piston 140 abuts the bottom surface of the cylinder bore 64 at the protrusion 154, and the spool 66 is in the original position where the control pressure port 90 communicates with the second low pressure port 88.

The control piston 140 advances when the master cylinder hydraulic pressure is supplied to the control pressure chamber 142, and the control force in a direction for communicating the control pressure port 90 with the spool 66 via the moving coil 114 and the control pressure port 90 with the high pressure port 84. To act.

Further, the coil 12 of the force motor 110
When the exciting current is supplied to 8, the moving coil 114 is moved. The driving direction of the moving coil 114 can be changed by changing the direction of the exciting current, and a force in the same direction as the control force applied by the control piston 140 to the spool 66 is applied to the spool 66 to move the spool 66 forward, or An anti-control force opposite to the control force is applied to the control piston 140 so that the control piston 14
0 is retracted to allow the spool 66 to retract.

When the force motor 110 applies a force to the spool 66 or the control piston 140 while the control piston 140 is exerting a control force on the spool 66, the front wheel cylinder 22 is controlled by the hydraulic pressure control valve 50. The supplied fluid pressure will be changed.
The force motor 110 constitutes an electric hydraulic pressure changing device. In addition, the control piston 140 moves the spool 6
By supplying an exciting current to the coil 128 and applying a force in the same direction as the control force to the spool 66 in a state in which the control force is not applied to the hydraulic pressure control valve 6, the hydraulic pressure control valve 50 is a conventional spool type electromagnetic hydraulic pressure control valve. The same function as the accumulator 82
The hydraulic pressure can be controlled to a height proportional to the exciting current of the coil 128 and supplied to the front wheel cylinder 22.

In any case, the force applied by the force motor 110 to the spool 66 or the control piston 140 is proportional to the exciting current of the coil 128, and the exciting current is controlled to an appropriate level to control the wheel cylinder hydraulic pressure to a desired value. The height can be changed and controlled.

The supply of the exciting current to the coil 128 of the force motor 110 is controlled by an electronic control unit (hereinafter abbreviated as ECU) 170. The ECU 170 includes rotation speed sensors 172, 174, 1 for detecting the rotation speeds of the left and right front wheels 18, 20 and the rear wheels 30, 32.
76 and 178 are connected, and wheel speed, wheel deceleration, vehicle body speed, etc. are calculated based on the connection. The ECU 170 also includes a pressure sensor 1 that detects the hydraulic pressure of the accumulator 82.
80 is connected and the start / stop of the motor 96 is controlled based on the output signal of the pressure sensor 180, so that the hydraulic pressure of the accumulator 82 is kept within a certain range.

A cut valve 190 as a hydraulic pressure increase gradient reducing device is provided in a portion of the liquid passage 14 closer to the front pressurizing chamber 13 than a portion where the liquid passage 16 is branched. The cut valve 190 has a valve housing 192 as shown in FIG. Valve housing 192
A cylinder bore 194, a valve hole 196, and a communication hole 198 that connects the cylinder bore 194 and the valve hole 196 are formed concentrically therein.

The cylinder bore 194 has a stepped shape, and the large-diameter hole portion 200 is provided with the port 202 by the port 202.
Connected to 3. A stepped cut piston 204 is also slidably fitted in the cylinder bore 194. The large diameter portion 208 of the cut piston 204 is the large diameter hole portion 2.
00 is loosely fitted, and the small-diameter portion 210 has the cylinder bore 19
The small-diameter hole 212 of No. 4 is sealed by an O-ring 214 and fitted in a liquid-tight and slidable manner. Also, the large diameter portion 2
A protrusion 216 is projectingly provided on 08 and is fitted into the communication hole 198. The cut piston 204 has a large-diameter hole portion 20.
By the spring 218 arranged in 0, the forward direction,
That is, the protrusion 216 is urged in the direction in which it projects into the valve hole 196.

The valve hole 196 is connected to the port 222, the master cylinder side liquid passages 14M and 16M, and the hydraulic pressure control valve 5 is provided.
It is connected to the control pressure chambers 142 of 0,52. Valve hole 19
A ball 224 fixed to the tip of the protrusion 216 of the cut piston 204 is accommodated in the valve 6, and is seated on a valve seat 228 formed at the end of the valve hole 196 on the side of the communication hole 198 to seat the large diameter hole 200. The valve hole 196 and the valve hole 196 are cut off from each other. As shown in FIG. 3, the cut piston 204 is biased by the spring 218 so that the large diameter portion 208 has the large diameter portion 208 on the side of the communication hole 198 of the large diameter hole portion 200 when the hydraulic pressure is not generated in the front pressure chamber 13. The ball 224 is separated from the valve seat 228 so that the ball 224 is in the original position in which it comes into contact with the end surface of the front end of the front pressure chamber 13 and the control pressure chamber 142.

The master cylinder side liquid passages 14M, 1
A brake fluid absorber 240 is provided between each of the 6M control fluid pressure chamber 142 and the cut valve 190. In the brake fluid absorber 240, the piston 244 is fluid-tightly and slidably fitted in the housing 242, and the spring 2
46, it is urged toward the liquid chamber 248 connected to the master cylinder liquid passages 14M and 16M.

A cut valve 250 having a hydraulic pressure cut-off function is provided at a portion of the master cylinder side liquid passage 26M on the master cylinder 12 side from a portion where the master cylinder side liquid passage 28M is branched. This cut valve 250
Has a valve housing 252 as shown in FIG.
4, a valve hole 256 and a communication hole 258 for connecting the cylinder bore 254 and the valve hole 256 are formed concentrically. The cylinder bore 254 has a stepped shape having a large diameter hole portion 260, a medium diameter hole portion 262 and a small diameter hole portion 264, and the first cut piston 266 and the second cut piston 268 are slidably fitted therein. There is.

The first cut piston 266 has a stepped shape, and the large diameter portion 270 is the large diameter hole portion 26 of the cylinder bore 254.
0 is sealed by an O-ring 272 to be fitted in a liquid-tight and slidable manner, and the small diameter portion 274 is sealed in an O-ring 276 and fitted in a medium-diameter hole portion 262 in a liquid-tight manner and slidably. Thereby, the front side of the large diameter portion 270 (the small diameter portion 27
(4 side), an annular hydraulic chamber 278 is formed, and the port 28
0, the liquid passage 282 (see FIG. 1) is connected to the front pressurizing chamber 13, and the annular surface 284 receives the front master cylinder hydraulic pressure.

The first cut piston 266 is also formed with a through hole 285 penetrating on the center line thereof, and the large diameter portion 2
Hydraulic chamber 286 formed on the rear side of 70 and the medium-diameter hole portion 26.
The fluid pressure chamber 288 formed inside 2 is communicated. The hydraulic chamber 288 is connected to the rear pressurizing chamber 15 at the port 290, and the first cut piston 266 is
Rear master cylinder hydraulic pressure is applied to the rear end surface of the large diameter portion 270 and the end surface of the small diameter portion 274, respectively.

The second cut piston 268 also has a stepped shape, and the large diameter portion 296 has the medium diameter hole portion 26 of the cylinder bore 254.
2 is loosely fitted, the small diameter portion 298 is loosely fitted in the through hole 285 formed in the first cut piston 266, and the small diameter portion 264 of the cylinder bore 254 is sealed by the O-ring 300 to be liquid-tight and slidable. It is movably fitted. The large diameter portion 296 is provided with the protrusion 302 and is fitted into the communication hole 258.
68 is the forward direction, that is, the projection 302 is provided with the valve hole 256 by the spring 304 arranged in the medium diameter hole portion 262.
It is urged in the direction to project inward.

The valve hole 256 is provided with the port 308 and the fluid pressure control valves 54, 5 by the master cylinder side fluid passages 26M, 28M.
6 is connected to the control pressure chamber 142. Also, the valve hole 25
6 accommodates the ball 310 fixed to the protrusion 302, and the valve seat 256 is seated on the valve seat 314 formed at the end of the valve hole 256 on the communication hole 258 side.
The communication with 56 is cut off. When no hydraulic pressure is generated in the front pressure chamber 13 and the rear pressure chamber 15, the first and second cut pistons 266 and 268 are urged by the spring 304, and as shown in FIG.
The large diameter portion 270 of the first cut piston 266 has the large diameter hole portion 2
The second cut piston 268 is in the original position where it comes into contact with the end surface of the small-diameter hole portion 264 side, and the large-diameter portion 296 is in the original position where it comes into contact with the end surface of the medium-diameter hole portion 262 on the communication hole 258 side. The ball 310 is separated from the valve seat 314 so that the rear pressure chamber 15 and the control pressure chamber 142 communicate with each other.

A cut valve 250 with a hydraulic pressure cut suppressing function for the master cylinder side liquid passages 26M and 28M and a hydraulic pressure control valve 5
A brake fluid absorber 320 similar to the brake fluid absorber 240 is provided between the brake fluid absorbers 4 and 56.

Next, the operation will be described. During non-braking, the spool 66 of the hydraulic control valves 50, 52, 54 and 56, the reaction piston 76, the moving coil 114 and the control piston 140 are in the original position shown in FIG. The two low pressure ports 88 communicate with each other. Further, the cut valve 190 and the cut valve 250 with the hydraulic pressure cut suppression function are in the states shown in FIGS. 3 and 4, respectively, and the front pressure chamber 13 and the rear pressure chamber 15 are respectively controlled by the hydraulic pressure control valves 50, 52. , 54, 56 control pressure chamber 14
It is connected to 2.

Brake pedal 1 for suppressing wheel rotation
When 0 is depressed, hydraulic pressure is generated in each of the front pressure chamber 13 and the rear pressure chamber 15. The hydraulic pressure of the master cylinder for the front passes through the cut valve 190 and the hydraulic pressure control valve 5
It is supplied to the control pressure chamber 142 of 0,52. At this time, the urging force F _{S1 of the} spring 218 is applied to the cut piston 204.
And the force P _MF · S _{3 obtained} by multiplying the cross-sectional area S ₃ of the small diameter portion 210 by the front master cylinder hydraulic pressure P _MF act in the opposite directions, but the front master cylinder hydraulic pressure P _MF is the set value. In the following states, the front master cylinder hydraulic pressure is not supplied to the control pressure chamber 142 without allowing the hydraulic pressure to be supplied to the control pressure chamber 142, and the hydraulic pressure in the control pressure chamber 142 is the same as the front master cylinder hydraulic pressure as shown in FIG. Increase. The supply cut of the front master cylinder hydraulic pressure P _MF will be described later.

Further, the hydraulic pressure of the master cylinder for the rear passes through the cut valve 250 with the hydraulic pressure cut suppressing function and the hydraulic pressure control valve 5
It is supplied to 4, 56 control pressure chambers 142. In the cut valve 250, the front master cylinder hydraulic pressure is supplied to the annular hydraulic chamber 278, and the hydraulic chambers 286 and 288 are supplied.
Although the rear master cylinder hydraulic pressure is supplied to the rear master cylinder hydraulic pressure, since the front master cylinder hydraulic pressure and the rear master cylinder hydraulic pressure are equal, the first cut piston 266 has a force based on the front master cylinder hydraulic pressure and a rear master cylinder hydraulic pressure. And the force based on the master cylinder hydraulic pressure act in opposite directions with equal magnitudes, and the first cut piston 266 does not move.

The second cut piston 268 has a biasing force F _S2 of the spring 304 and a force P _MR · which is obtained by multiplying the cross-sectional area S ₄ of the small diameter portion 298 by the rear master cylinder hydraulic pressure P _MR.
Although S ₄ acts in the opposite direction to each other, the master cylinder hydraulic pressure P _MR for the rear is kept at the original position when it does not exceed the set value, and the master cylinder hydraulic pressure P _MR for the rear to the control pressure chamber 142 is maintained.
Is allowed, and the hydraulic pressure in the control pressure chamber 142 increases with the hydraulic pressure for the rear master cylinder as shown in FIG. The cutting of the supply of the rear master cylinder hydraulic pressure P _MR and the suppression of the cutting will be described later.

By supplying hydraulic pressure to the control pressure chamber 142, the control piston 140 advances and the moving coil 1
14 advances spool 66 through control pressure port 9
0 is blocked from communicating with the second low pressure port 88, and is further communicated with the high pressure port 84 by advancing the spool 66, and the wheel cylinders 22, 24, 34, 3 are connected.
The brake fluid of the accumulator 82 is supplied to the valve 6. At the same time, the reaction force piston 76 receives the hydraulic pressure of the control pressure port 90, and the reaction force is applied to the spool 66, and the wheel cylinder hydraulic pressure P _W is controlled to the height represented by the equation (1).

Pw = (S ₁ / S ₂ ) Pm (1) where, S ₁ : cross-sectional area of control piston 140 S ₂ : cross-sectional area of reaction force piston 76 Pm: master cylinder hydraulic pressure

As is apparent from the equation (1), the master cylinder hydraulic pressure is boosted at a ratio determined by the cross-sectional area of the control piston 140 and the cross-sectional area of the reaction force piston 76, so that the wheel cylinders 22, 24, 34, 36. Be transmitted to. The master cylinder hydraulic pressure is generated in proportion to (proportionate to) the stepping force of the brake pedal 10, and the hydraulic pressure of the accumulator 82 is set to a height corresponding to the stepping force of the brake pedal 10 without using the stepping force sensor. The pressure can be reduced.

As described above, the master cylinder 12 functions as a device for supplying the pilot pressure to the hydraulic pressure control valve 50, and the amount of brake fluid used for that purpose is small. However, the master cylinder side liquid passages 14M, 16M, 26M,
Since the brake fluid absorbers 240 and 320 are provided in the 28M, respectively, the driver can step on the brake pedal 10 with a good feeling. When the amount of brake fluid used is small, the stepping stroke becomes short and it feels hard, while the brake fluid absorbers 240, 32
If 0 is provided, the brake fluid absorbers 240, 32
The brake fluid is absorbed at zero and you can step on with a comfortable feeling. Further, the rising gradient of the wheel cylinder hydraulic pressure with respect to the stepping stroke can be made gentle, and it becomes easy to perform a delicate operation.

When the depression force of the brake pedal 10 is excessive compared with the friction coefficient of the road surface and the slip ratio of the wheels exceeds the proper range, antilock control is performed. In this case, the counter control force is applied to the coil 128 of the force motor 110 by the control of the ECU 170.
An exciting current in the direction of adding 0 is supplied. As a result, the control piston 140 is retracted, the spool 66 is retracted, the control pressure port 90 is communicated with the second low pressure port 88, and the wheel cylinder hydraulic pressure is reduced. When the wheel slip is reduced, the exciting current of the coil 128 is reduced, the spool 66 is advanced by the advance of the control piston 140, and the control pressure port 90 is changed to the second low pressure port 88.
And the control pressure port 90 is brought into a state of communicating with neither the high pressure port 84 nor the high pressure port 84, and the wheel cylinder hydraulic pressure is held or increased. The wheel cylinder hydraulic pressure Pw at the time of antilock control is expressed by the equation (2).

Pw = (S ₁ / S ₂ ) Pm + F ₁ / S ₂ (2) where, F ₁ is an anti-control force (negative value) applied by the force motor 110 to the control piston 140.

As is clear from the equation (2), the anti-control force F
By controlling ₁ , the wheel cylinder hydraulic pressure can be controlled and the slip ratio of the wheel can be maintained within an appropriate range.

The acceleration slip control is performed as follows.
Since the brake pedal 10 is not depressed when the acceleration slip control is executed, the hydraulic pressure control of the hydraulic pressure control valves 50 to 56 is not performed, and the hydraulic pressure of the accumulator 82 is electrically controlled only by the force motor 110. Coil 12
8, an exciting current in a direction in which the force motor 110 applies a force in the same direction as the control force applied to the spool 66 by the control piston 140 to the spool 66, and the hydraulic pressure of the accumulator 82 is expressed by the equation (3). The wheel cylinder hydraulic pressure Pw is controlled to a certain height.

[0048] _{Pw = F 2 / S 2 ·····} (3) However, F _2: force the force F ₂ which force motor 110 applies to the spool 66 is proportional to the exciting current of the coil 128, adjusting the excitation current However, the rotation of the wheels is appropriately suppressed by changing the magnitude of the force F ₂ , and the slip during acceleration is prevented from becoming excessive.

When the brake pedal 10 is strongly depressed and a hydraulic pressure exceeding the set value is generated in the front pressure chamber 13 and the rear pressure chamber 15, the cut valve 190 and the cut valve 250 with a hydraulic pressure cut suppression function are activated. The supply of the master cylinder hydraulic pressure to the control pressure chamber 142 is cut off.

In the cut valve 190, the front master cylinder hydraulic pressure rises and the small diameter portion 21 is added to the front master cylinder hydraulic pressure P _MF acting on the cut piston 204.
If the force obtained by multiplying the cross-sectional area S _{3 of} 0 exceeds the urging force F _S1 of the spring 218, the cut piston 204 moves to the spring 21.
The ball 224 moves backward against the biasing force of
Seated on the front master cylinder hydraulic pressure control chamber 1
Cut off supply to 42. Therefore, as shown in FIG. 5, the hydraulic pressure in the control pressure chamber 142 is maintained at the height when the ball 224 is seated on the valve seat 228 even if the front master cylinder hydraulic pressure rises. Thus cut piston 20
The front master cylinder hydraulic pressure (referred to as a cut pressure) P _MFCUT when the supply of the master cylinder hydraulic pressure to the control pressure chamber 142 is cut off when 4 _{starts to move backward} is expressed by the following equation (4). P _MFCUT = F _S1 / S ₃ (4)

Further, a cut valve 25 with a hydraulic pressure cut suppression function
Similarly, at 0, the supply of the master cylinder hydraulic pressure to the control pressure chamber 142 is cut by the cut pressure P _MRCUT represented by P _MRCUT = F _S2 / S ₄ (5).

The cut pressures P _MFCUT and P _MRCUT at the start of hydraulic pressure supply cut are the cut pistons 204 and 268.
The height can be set to an appropriate height by changing the urging force of the springs 218 and 304 for urging and the cross-sectional area of the small diameter portions 210 and 298. In the present embodiment, the maximum height required for normal braking is obtained. Is set to the value of. That is, at the time of braking on a dry asphalt road, even if the hydraulic pressure is further increased, the slip force only increases, the braking force decreases, and the hydraulic pressure is set to be slightly higher than the hydraulic pressure that requires antilock control.

When the master cylinder hydraulic pressure exceeds the set value and the cut valves 190 and 250 cut off the supply of the master cylinder hydraulic pressure to the control pressure chamber 142, the force motor 110 applies an anti-control force to the control piston 140. When the antilock control is performed, the brake fluid pushed out of the control pressure chamber 142 due to the backward movement of the control piston 140 is absorbed by the brake fluid absorbers 240 and 320.

By preventing an excessive master cylinder hydraulic pressure from being supplied to the control pressure chamber 142 in this manner, it is possible to obtain the hydraulic control valves 50, 52, 54 and 56 that are small in size and have excellent input / output characteristics. As shown in the graph of FIG. 7, the larger the diameter of the control piston 140, the smaller the hysteresis of the control pressure (output) output from the control pressure port 90, and the better the response. This is because as the diameter of the control piston 140 increases, both the control force applied to the spool 66 by the control piston 140 and the frictional resistance between the control piston 140 and the inner peripheral surface of the cylinder bore 64 increase, but the increase rate of the former is the increase rate of the latter. This is because the control piston 140 is much larger than the above and it becomes easier for the control piston 140 to overcome frictional resistance and move.

Therefore, it is desirable that the diameter of the control piston 140 is large in order to improve the input / output characteristics. However, if the diameter of the control piston 140 is increased, the force motor 110 together with the reaction force piston 76 which opposes this is increased.
Inevitably, the hydraulic control valve becomes large. Further, if the control piston 140 is made smaller, the force motor 110 can be made smaller, but the input / output characteristics deteriorate. On the other hand, if the height of the hydraulic pressure supplied to the control pressure chamber 142 is limited so that the control force does not exceed a certain level, the control force can be suppressed without reducing the diameter of the control piston 140, The force motor 110 may be of a size that can overcome the control force due to the limited hydraulic pressure, has excellent input / output characteristics, and can provide a small hydraulic control valve.

The hydraulic pressure cut suppressing function of the cut valve 250 with the hydraulic pressure cut suppressing function will be described. If hydraulic pressure is no longer supplied to the front wheel cylinders 22 and 24 in the second brake system 40 due to damage to the brake piping, etc.,
The hydraulic pressure is not transmitted to the hydraulic chamber 278 of the cut valve 250 with the hydraulic pressure cut suppression function. Therefore, the first cut piston 266 moves toward the second cut piston 268 while compressing the spring 304, and the second cut piston 26
8, the second cut piston 268 receives a force P _MR · S _{5 obtained} by multiplying the area S ₅ of the annular surface 284 of the first cut piston 266 by the rear master cylinder hydraulic pressure P _MR .
Cross-sectional area S ₄ of the small diameter portion 298 of the second cut piston 268
Rear master cylinder hydraulic pressure P _MR multiplied by force P _MR・ S ₄
It becomes a state where and act in the opposite directions. Therefore, if the area S ₅ of the annular surface 284 is made larger than the cross-sectional area S ₄ of the small diameter portion 298, the second cut piston 268 is kept in contact with the end surface of the medium diameter hole portion 262 and the ball 31
0 does not sit on the valve seat 314, and the rear master cylinder hydraulic pressure is maintained in a state of being supplied to the control pressure chamber 142, and the hydraulic pressure of the control pressure chamber 142 is as shown by the chain double-dashed line in FIG. Rises with the rear master cylinder fluid pressure.

As described above, the second cut piston 268 and the ball 31 of the cut valve 250 with the hydraulic pressure cut suppression function.
0, the valve seat 314 and the spring 304 constitute a hydraulic pressure increase gradient reducing device, and the first cut piston 266, the hydraulic chambers 278, 286, 288 constitute hydraulic pressure increase gradient decreasing function suppressing means.

Even if the hydraulic pressure is not supplied to the front wheel cylinders 22 and 24 in the second brake system 40 and the rotation of the left and right front wheels 18 and 20 is not suppressed,
Since the hydraulic pressure is not cut, the hydraulic pressure supplied to the rear wheel cylinders 34, 36 increases, the rear wheel braking force increases, and the decrease in the braking force of the vehicle as a whole can be reduced.
When the rotations of the left and right front wheels 18 and 20 are not suppressed, the load movement of the vehicle is small, so that the reduction in the load on the rear wheel side is small and the rear wheel braking force can be increased, and the braking force is secured. It is possible to favorably avoid an increase in the braking distance.

Further, according to the brake fluid pressure control device of this embodiment, the accumulator 82 is used without using a sensor.
The hydraulic pressure of the wheel cylinders 22, 24, 3 is reduced to a hydraulic pressure (proportional) corresponding to the depression force of the brake pedal 10.
Therefore, a highly reliable brake fluid pressure control device can be obtained.

Further, the boosting factor of the master cylinder hydraulic pressure is
It can be adjusted by changing the ratio of the cross-sectional areas of the control piston 140 and the reaction piston 76. Therefore, it is not necessary to change the master cylinder and the brake pedal in order to obtain different wheel cylinder hydraulic pressures depending on the type of automobile, and it is possible to reduce costs by sharing parts such as the master cylinder.

Another embodiment of the present invention is shown in FIG. In this embodiment, instead of the hydraulic pressure control valves 50 and 52 in the second brake system 40 which is the front wheel system, the electromagnetic opening / closing valves 330 and 33 are used.
2, an anti-lock actuator 33 including a pump 334, a reservoir 336 and an accumulator 337
8 is provided to perform antilock control.

The front pressure chamber 13 and the left and right front wheels 18,
In the liquid passages 340 and 342 connecting with 20, respectively,
A normally open electromagnetic on-off valve 330 is provided. A reservoir passage 344 is provided in a portion between the front wheel cylinders 22 and 24 and the electromagnetic opening / closing valve 330.
36 is connected, and a normally closed electromagnetic opening / closing valve 332 is provided in the reservoir passage 344. Solenoid on-off valve 33
By opening and closing 0,332, the front wheel cylinder 2
2 and 24 are connected to the front pressurizing chamber 13 to increase the hydraulic pressure, and when the hydraulic pressurization chamber 13 is disconnected from the front pressurizing chamber 13, the hydraulic pressure decreases. The depressurized state is maintained and the hydraulic pressure that is not communicated with either is maintained at a constant pressure.

The brake fluid discharged from the front wheel cylinders 22 and 24 to the reservoir 336 is collected by the motor 34.
8 is pumped up by the pump 334 and stored in the accumulator 337, and is returned to the portion of the liquid passage 340 on the electromagnetic opening / closing valve 330 side from the portion where the cut valve 190 is provided, if necessary. The anti-lock actuator 338 is of a reflux type. Accumulator 337
The stored fluid pressure is set to be slightly higher than the cut pressure of the cut valve 190.

In the second brake system 40, antilock control is performed by switching the electromagnetic opening / closing valves 330 and 332. Since the cut valve 190 is provided, the cutting is performed when the front master cylinder hydraulic pressure reaches the cut pressure as in the case of the above embodiment. After that, the accumulator 337 functions as a hydraulic pressure source, and the pump 334
Is required to pump up the brake fluid against the stored fluid pressure of the accumulator 337 which is lower than the front master cylinder fluid pressure, and a small one is sufficient. Further, when the antilock control is performed by switching the front wheel cylinders 22 and 24 to each of the pressure increasing, depressurizing, and pressure holding states, the hydraulic pressure does not suddenly change, and the antilock control can be accurately performed. .

In the present embodiment, it is desirable to provide a relief valve between the discharge side of the pump 334 and the reservoir 336. When the relief valve is provided, the accumulator 337 can be omitted. Further, the cut valve 190 can be omitted, and in this case, the accumulator 337 and the relief valve can be omitted.

In each of the above embodiments, the first brake system 38 is provided with the cut valve 250 having the hydraulic pressure cut suppressing function. However, as shown in FIG. A cut valve 190 having no pressure cut suppressing function may be provided. This aspect is an embodiment of the invention of claim 1.

Further, the first and second brake systems 38, 40
Cut valve 1 which has neither hydraulic cut suppression function
When 90 is provided, as shown in FIG. 10, for the second brake system 40, which is the front wheel brake system, as in the embodiment shown in FIG. 8, an antilock actuator 338 is used instead of the hydraulic pressure control valves 50 and 52. It may be provided.

Further, in each of the above embodiments, the cut valve 1
90 and 250 apply master cylinder hydraulic pressure to the cut pistons 204 and 268, and when the master cylinder hydraulic pressure exceeds a set value, the cut pistons 204 and 268 are retracted to control the hydraulic pressure to the control pressure chamber 142. Although the supply is cut off, as shown in FIG. 11, the hydraulic pressure increase gradient reducing device may be configured by the electromagnetic opening / closing valve 370 and the hydraulic pressure sensor 372.

In the present hydraulic brake device, the second brake system 40 is provided with the antilock actuator 338 to perform antilock control, but is not provided with the cut valve, and The first brake system 38 is provided with one hydraulic pressure control valve 374 so that the hydraulic pressures supplied to the rear wheel cylinders 34, 36 are commonly controlled. The liquid passage 3 for supplying the hydraulic pressure of the rear pressurizing chamber 15 to the hydraulic pressure control valve 374.
An electromagnetic opening / closing valve 370 and a hydraulic pressure sensor 372 are provided on the ECU 76. When the rear master cylinder hydraulic pressure detected by the hydraulic pressure sensor 372 exceeds a set value, the ECU 1
70 closes the electromagnetic opening / closing valve 370 to block the supply of hydraulic pressure to the control pressure chamber of the hydraulic pressure control valve 374. Front pressure room 1
The hydraulic pressure supplied from 3 to the front wheel cylinders 22 and 24 may be detected by the hydraulic pressure sensor, and the solenoid opening / closing valve 370 may not be closed when the hydraulic pressure is not supplied to the front wheel cylinders 22 and 24. In this case, the portion that does not close the electromagnetic opening / closing valve 370 based on the detection of the hydraulic pressure sensor that detects the hydraulic pressure of the front pressurizing chamber 13 and the hydraulic pressure sensor of the ECU 170 suppresses the hydraulic pressure increase gradient decreasing function. It constitutes a means.

Further, in each of the above embodiments, the cut valve 19
0 and 250 are supposed to be closed by the hydraulic pressure on the master cylinder side acting on the cut pistons 204 and 268, but as shown in FIG. 12, the cut valves are closed by the hydraulic pressure on the hydraulic control valve side. It may be 380.

As shown in detail in FIG. 13, the cut valve 380 includes a cylinder bore 3 inside a valve housing 382.
84, a valve hole 386, and a communication hole 388 that connects the cylinder bore 384 and the valve hole 386 are formed concentrically. The valve hole 386 is connected to the rear pressurizing chamber 15 by a port 390, and the communication hole 388 is a port. 392 is connected to the control pressure chamber 142 of the hydraulic control valves 54 and 56. A cut piston 396 is fitted in the cylinder bore 384 so as to be liquid-tight and slidable and a spring 398.
Is urged in such a direction as to contact the shoulder surface 400 of the cylinder bore 384 on the communication hole 388 side. Also, the valve hole 3
The valve element 402 is disposed in the 86. A protrusion 404 is provided on the valve element 402 so as to be fitted into the communication hole 388, and the spring 406 urges the valve element 402 so that the valve element 402 is seated on the valve seat 408.

When no hydraulic pressure is generated in the rear pressurizing chamber 15, the valve element 402 is pushed by the cut piston 396 and is separated from the valve seat 408, so that the rear pressurizing chamber 15 and the control pressure chamber 142 are separated from each other. It is in communication. Rear pressure chamber 1
If the hydraulic pressure of 5 exceeds the set value, the cut piston 396 moves backward against the biasing force of the spring 398, and the valve 402
Is seated on the valve seat 408 to block the communication between the master cylinder 12 and the control pressure chamber 142, and an excessive supply of hydraulic pressure to the control pressure chamber 142 is prevented.

In this state, when the coil 128 of the force motor 110 is excited and antilock control is performed, the cut piston 396 compresses the spring 398 by the brake fluid pushed out of the control pressure chamber 142 by the retreat of the control piston 140. It is absorbed by retreating, and anti-lock control is performed without trouble. Cut valve 3
80 also serves as a brake fluid absorber. Also,
When the brake fluid in the control pressure chamber 142 leaks, the hydraulic pressure in the control pressure chamber 142 decreases and the cut piston 396 moves forward to open the cut valve 380. Is replenished.

Further, in each of the above embodiments, when the master cylinder hydraulic pressure reaches the set value, the hydraulic pressure supply to the control pressure chamber of the hydraulic pressure control valve is cut off, and the rising gradient of the hydraulic pressure becomes zero. Although it is possible to suppress the pressure, a proportioning valve may be provided in place of the cut valve to suppress the rising gradient of the hydraulic pressure after the master cylinder hydraulic pressure reaches a set value.

In this case, the proportioning valve is used as a proportioning bypass valve, and the proportioning valve is bypassed when hydraulic pressure is not normally supplied to the wheel cylinders in a system different from the system in which the proportioning bypass valve is provided. The hydraulic pressure may be directly supplied from the pressurizing chamber to the wheel cylinder to the hydraulic pressure control valve. The proportioning valve and the proportioning bypass valve are well known and will not be illustrated and described.

The cut valve 25 with a hydraulic pressure cut-off function
At 0, when hydraulic pressure is no longer supplied to the front wheel cylinders 22 and 24, the first cut piston 2
Although 66 was in contact with the second cut piston 268, the second cut piston 268 was pressed against the end surface of the medium diameter hole portion 262 so that the cut valve 250 remained open. It is not essential to abut the second cut piston 268. Even if only the first cut piston 266 is moved to the second cut piston 268 side by compressing the spring 304, the urging force of the spring 304 applied to the second cut piston 268 is increased and the valve closing pressure is increased. This is because the function of decreasing the rising gradient of the hydraulic pressure supplied to the control valve can be suppressed. For example, a cut valve 250 with a hydraulic pressure cut suppression function
Is configured to remain open when no hydraulic pressure is supplied to the front wheel cylinders 22 and 24.
When the hydraulic pressure supplied to the valves 2 and 24 becomes lower than that when the hydraulic pressure is normally supplied, the valve closing pressure becomes high due to the compression of the spring 304, and the effect of suppressing the upward gradient decreasing function of the hydraulic pressure is obtained. Also, when no hydraulic pressure is supplied to the front wheel cylinders 22 and 24, the spring 304
The valve closing pressure may be increased only by the compression of the above, so that the function of decreasing the rising gradient of the hydraulic pressure may be suppressed.

Furthermore, when a plurality of brake systems are provided,
The number of lines is not limited to two, and three or more lines may be provided. in this case,
A hydraulic control valve, an electric hydraulic pressure changing device, and a hydraulic pressure rising gradient reducing device may be provided in all systems, and only in some systems, and in some other systems, the master cylinder hydraulic pressure is applied to the wheel. It may be supplied to the cylinder as it is. When the hydraulic pressure control valve, the electric hydraulic pressure changing device, and the hydraulic pressure increase gradient reducing device are provided in a plurality of systems, it is desirable to provide hydraulic pressure increase gradient decreasing function suppressing means in the rear wheel system. When the hydraulic pressure increase gradient decreasing function suppressing means is provided in a plurality of systems, the brake system provided with the hydraulic pressure increasing gradient decreasing function suppressing means is the first brake system, and the hydraulic pressure increasing gradient decreasing function suppressing means is caused to function. The brake system is the second brake system.

Further, only one brake system may be provided, and a hydraulic pressure control valve, an electric hydraulic pressure changing device and a hydraulic pressure rising gradient reducing device may be provided.

Further, in each of the above embodiments, the cut valve 1
At 90 and 250, the balls 224 and 314 were fixed to the cut pistons 204 and 268, but the valve hole 19
It may be movably disposed in 6,256. in this case,
The ball shall be biased by the spring in the direction to be seated on the valve seat, and shall have the biasing force that keeps the ball seated on the valve seat even if the master cylinder hydraulic pressure rises further beyond the set value. .

Further, the control pressure chamber 1 of the hydraulic pressure control valves 50 to 56
The set value of the master cylinder hydraulic pressure with which the rising gradient of the hydraulic pressure supplied to 42 is reduced is not limited to a value slightly larger than the hydraulic pressure that requires antilock control on the dry asphalt road. For example, the set value can be changed according to the condition of the road surface or the like.

Further, the hydraulic control valve 50 of each of the above embodiments,
The reaction force piston 76 constitutes a reaction force means at 52, 54 and 56, and the control piston 1 is provided separately from the spool 66.
Although 40 and 200 are provided, the control pressure of the control pressure port is directly applied to the spool 66, a part of the spool 66 functions as a reaction force piston, and the hydraulic pressure of the pressurizing chamber is directly applied to the spool 66. A portion of the spool may act to act as a control piston.

Further, although the electric hydraulic pressure changing device is a force motor, any device that can apply an electrically controlled force to the hydraulic pressure control valve, such as a solenoid, can be adopted.

Furthermore, the respective constituent elements of the above-mentioned respective embodiments can be adopted in different combinations.

In addition, the present invention can be carried out in various modified and improved modes based on the knowledge of those skilled in the art without departing from the scope of the claims.

[Brief description of drawings]

FIG. 1 is a system diagram of a hydraulic brake device that is an embodiment of the present invention.

FIG. 2 is a front sectional view showing a hydraulic pressure control valve and a force motor provided in the hydraulic brake device.

FIG. 3 is a front sectional view showing a cut valve provided in the hydraulic brake device.

FIG. 4 is a front sectional view showing a cut valve with a hydraulic pressure cut suppressing function provided in the hydraulic brake device.

FIG. 5 is a graph illustrating a hydraulic pressure cut function of the cut valve.

FIG. 6 is a graph illustrating a hydraulic pressure cut function and a hydraulic pressure cut suppression function of the cut valve with the hydraulic pressure cut suppression function.

FIG. 7 is a graph showing a relationship between a diameter of a control piston of the hydraulic control valve and input / output characteristics.

FIG. 8 is a system diagram of a hydraulic brake device according to another embodiment of the present invention.

FIG. 9 is a system diagram of a hydraulic brake device according to still another embodiment of the present invention.

FIG. 10 is a system diagram of a hydraulic brake device according to still another embodiment of the present invention.

FIG. 11 is a system diagram of a hydraulic brake device according to still another embodiment of the present invention.

FIG. 12 is a system diagram of a hydraulic brake device according to still another embodiment of the present invention.

13 is a front sectional view showing a cut valve provided in the hydraulic brake device shown in FIG.

[Explanation of symbols]

 10 brake pedal 12 master cylinder 13,15 pressurizing chamber 18 left front wheel 20 right front wheel 22,24 front wheel cylinder 30 left rear wheel 32 right rear wheel 34,36 rear wheel cylinder 38 first brake system 40 second brake system 50, 52, 54, 56 Hydraulic control valve 82 Accumulator 110 Force motor 190 Cut valve 250 Cut valve with hydraulic cut suppression function 380 Cut valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kiyoji Nakamura 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd.

Claims (2)

[Claims] 1. A master cylinder for generating a hydraulic pressure in a pressurizing chamber according to an operating force of a brake operating member, and a brake that is actuated by supplying hydraulic pressure to a wheel cylinder to suppress wheel rotation. A hydraulic pressure source different from the reservoir and the master cylinder, and provided between the master cylinder, the wheel cylinder, the reservoir and the hydraulic pressure source, and the hydraulic pressure of the hydraulic pressure source depends on the hydraulic pressure of the master cylinder. A hydraulic pressure control valve that is controlled to a height and is supplied to the wheel cylinder, and an electrical pressure control valve that changes the hydraulic pressure supplied to the wheel cylinder by applying an electrically controlled force to the hydraulic pressure control valve. A hydraulic pressure changing device, provided between the master cylinder and the hydraulic pressure control valve, and the hydraulic pressure supplied from the pressurizing chamber to the hydraulic pressure control valve when the hydraulic pressure in the pressurizing chamber exceeds a set value. The rising slope of A hydraulic brake device comprising: a hydraulic pressure increase gradient reducing device for reducing the hydraulic pressure. 2. A master cylinder having a plurality of pressurizing chambers for generating a hydraulic pressure in each pressurizing chamber according to an operating force of a brake operating member; A plurality of brakes that form a brake system and operate by supplying hydraulic pressure to the wheel cylinders to respectively suppress the rotation of the wheels; a reservoir; a hydraulic pressure source different from the master cylinder; Is provided between the first pressurizing chamber and the first wheel cylinder of the first brake system, which is one of the brake systems, the reservoir, and the hydraulic pressure source. A hydraulic pressure control valve for controlling the height according to the hydraulic pressure of the pressure chamber to supply the hydraulic pressure control valve to the first wheel cylinder, and a force electrically controlled to the hydraulic pressure control valve to apply the hydraulic pressure control valve to the first wheel cylinder. Electrical to change the hydraulic pressure supplied to A pressure changing device, and the pressure control valve, provided between said first pressure chamber,
A hydraulic pressure rising gradient reducing device that reduces a rising gradient of the hydraulic pressure supplied from the first pressurizing chamber to the hydraulic pressure controlling valve when the hydraulic pressure supplied to the hydraulic pressure controlling valve exceeds a set pressure; When the brake fluid is no longer supplied to the second wheel cylinder in the second brake system, which is another one of the above-mentioned brake systems, the hydraulic pressure increase gradient decreasing device is suppressed to have the hydraulic pressure increase gradient decreasing function. A hydraulic brake device including a hydraulic pressure rising gradient decreasing function suppressing unit.