JPH08142835A - Brake fluid pressure control device - Google Patents

Abstract

PURPOSE: To provide a brake fluid pressure control device that can perform anti-lock control and accelerating slip control with simple constitution and also can reduce pressure quickly. CONSTITUTION: A normally opened solenoid switching valve 64 and a pressure intensifying pumping device 76 are provided in a pressure intensifying passage 24 connecting a master cylinder 12 and a rear wheel cylinder 28 to each other, and a normally closed solenoid switching valve 70 and a pressure reducing pumping device 106 are provided in a pressure reducing passage 68. At the time of anti-lock control, a brake fluid in the rear wheel cylinder 28 is made flow out to a quick pressure reducing reservoir 74 and also returned to the pressure intensifying passage 24 by the opening/closing of the solenoid switching valves 64, 70 and the actuation of the pressure reducing pumping device 106 so as to dissolve excessive slip by intensifying, reducing and holding wheel cylinder pressure. At the time of accelerating slip control, a brake fluid is fed to the rear wheel cylinder 28 from the pressure intensifying pumping device 76, and the wheel cylinder pressure is intensified, reduced and held by the opening/closing of the solenoid switching valves 64, 70 to suppress the rotation of driving wheels.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake fluid pressure control device, and more particularly to a brake fluid pressure control device capable of performing antilock control and acceleration slip control.

[0002]

2. Description of the Related Art Although antilock control and acceleration slip control are widely performed in vehicles, recently, there has been a strong demand for cost reduction of a brake fluid pressure control device capable of performing both of them. Japanese Patent Laid-Open No. 1-2932
The brake fluid pressure control device described in Japanese Patent No. 61 proposes a proposal therefor. In the brake fluid pressure control device described in this publication, the pressure reducing passage for antilock control also functions as the pressure increasing passage for acceleration slip control. A normally open first electromagnetic on-off valve is provided in the main fluid passage connecting the master cylinder and the wheel cylinder. The wheel cylinder is connected to the main fluid passage by a return passage, and the return passage is provided with a normally closed second electromagnetic on-off valve and a pump. , Pump positive,
The reverse rotation increases, maintains, and reduces the wheel cylinder pressure. During depressurization of the anti-lock control, the first electromagnetic opening / closing valve is closed and the second electromagnetic opening / closing valve is opened, so that the brake fluid flows out from the wheel cylinder. The brake fluid that has flowed out is returned to the main fluid passage by the normal rotation of the pump.

At the time of increasing the pressure in the acceleration slip control, the first solenoid on-off valve is closed and the second solenoid on-off valve is opened, and the brake fluid in the main reservoir connected to the master cylinder is rotated by the reverse rotation of the pump. Through the return passage and is supplied to the wheel cylinder. By doing so, the configuration of the brake fluid pressure control device can be simplified, and the cost can be reduced.

[0004]

However, in this brake fluid pressure control device, it is difficult to sharply reduce the wheel cylinder pressure during antilock control. It is widely practiced to connect a reservoir for rapid pressure reduction to the return passage for rapid pressure reduction so that the brake fluid in the wheel cylinders can flow out rapidly, but this is difficult. If the brake fluid pressure control device is provided with a sudden pressure reducing reservoir, the brake fluid is absorbed in the sudden pressure reducing reservoir when the pressure is increased in the acceleration slip control, and the increase of the wheel cylinder pressure is delayed. If an electromagnetic on-off valve is provided between the return passage and the rapid depressurization reservoir, the electromagnetic on-off valve can be closed to prevent the brake fluid from flowing into the rapid depressurization reservoir when the pressure is increased during acceleration slip control. The configuration becomes complicated. In view of the above circumstances, the first and second inventions can perform both antilock control and acceleration slip control with a simple configuration, and further increase pressure during acceleration slip control and antilock control. An object of the present invention is to provide a brake fluid pressure control device that does not cause a delay in depressurization.

[0005]

In order to solve the above problems, a brake fluid pressure control device according to the first aspect of the present invention includes (a) a master cylinder and (b) a wheel cylinder to suppress wheel rotation. Brake, (c) pressure increasing passage connecting the master cylinder and the wheel cylinder, (d) pressure reducing passage provided in parallel with the pressure increasing passage and connecting the master cylinder and the wheel cylinder, (e) It is provided in the booster passage,
An anti-lock control pressure increasing unit that allows the flow of brake fluid from the master cylinder to the wheel cylinder during anti-lock control, and (f) a pressure-reducing passage that is provided in the pressure-reducing passage. (G) A pressure reducing unit for anti-lock control that returns to the master cylinder side after flowing out to the reservoir, and (g) a hydraulic pressure source is provided in the pressure increase passage, and brake from the hydraulic pressure source to the wheel cylinder is provided during acceleration slip control. (H) A pressure increasing unit for acceleration slip control that allows the flow of liquid, and (h) A pressure reducing passage is provided in the pressure reducing passage, and during acceleration slip control, the brake fluid in the wheel cylinder is temporarily discharged to the sudden pressure reducing reservoir and then the hydraulic pressure source side. Deceleration unit for acceleration slip control to return to (i) anti-lock control pressure increasing unit and anti-lock control pressure reducing unit during braking To control the wheel slip within an appropriate range, and (j) control the acceleration slip control pressure increasing unit and the acceleration slip control depressurizing unit during acceleration to control the wheel slip within an appropriate range. And an acceleration slip control means for controlling the acceleration slip control.

The brake fluid pressure control device according to the second invention is
The anti-lock control pressure increasing unit is provided in the pressure increasing passage, and includes a pressure increasing on-off valve that allows and blocks communication between the master cylinder and the wheel cylinder, and the anti-lock control pressure reducing unit is connected to the pressure reducing passage. A rapid decompression reservoir and a decompression on-off valve that is provided in the decompression passage and allows and blocks communication between the rapid decompression reservoir and the wheel cylinders;
A decompression piston slidably fitted in the decompression housing is provided. A decompression pump chamber formed by the decompression housing and the decompression piston is connected to the decompression passage, and the decompression passage is decompressed. An intake valve that is provided closer to the rapid decompression reservoir side than the part to which the pump chamber is connected, and allows the flow of brake fluid from the rapid decompression reservoir side to the decompression pump chamber side, but blocks the reverse flow. It is provided on the master cylinder side from the part of the decompression passage where the decompression pump chamber is connected, and allows a flow of brake fluid from the decompression pump chamber side to the master cylinder side, but prevents it from flowing in the opposite direction. A pressure reducing pump device having a pressure reducing piston driving device that reciprocates the pressure reducing piston, and a pressure increasing unit for acceleration slip control, a pressure increasing on-off valve, and a pressure increasing house. A pressure boosting piston that is slidably fitted inside, and a pressure boosting pump chamber formed by the pressure boosting housing and the pressure boosting piston is connected to the pressure boosting passage, and a pressure boosting pump in the pressure boosting passage It is provided on the master cylinder side from the part where the chamber is connected and allows the brake flow from the master cylinder side to the pressure boosting pump chamber side, but prevents the flow in the opposite direction. It is provided on the wheel cylinder side from the part where the pump chamber is connected, and allows the flow of brake fluid from the booster pump chamber side to the wheel cylinder side, but reciprocally moves the discharge valve and piston that prevent the reverse flow. And a pressure boosting pump device having a pressure boosting piston drive device, the acceleration slip control depressurizing unit includes a depressurizing on-off valve, and a rapid depressurizing reservoir, and The lock control means controls the pressure-increasing on-off valve, the pressure-reducing on-off valve and the pressure-reducing pump device to perform anti-lock control, and the acceleration slip control means controls the pressure-increasing on-off valve, the pressure-reducing on-off valve and the pressure-increasing valve. The acceleration slip control is performed by controlling the pump device.

[0007]

In the brake fluid pressure control device according to the first aspect of the present invention, during braking, the fluid pressure generated in the pressurizing chamber of the master cylinder is transmitted to the wheel cylinders by the pressure increasing passages to suppress the rotation of the wheels. When the hydraulic pressure in the master cylinder is excessive with respect to the friction coefficient on the road surface and the wheel slip increases beyond the appropriate range, the flow of brake fluid from the master cylinder to the wheel cylinder in the antilock control booster unit increases. At the same time, the anti-lock control depressurizing unit causes the brake fluid in the wheel cylinders to rapidly flow out to the rapid depressurizing reservoir, so that the hydraulic pressure is rapidly reduced. As a result, if the slip of the wheels is reduced, the outflow of brake fluid from the wheel cylinders is stopped in the antilock control pressure reducing unit, and the brake fluid flow from the master cylinder to the wheel cylinders in the antilock control pressure increasing unit. Acceptable,
The hydraulic pressure in the wheel cylinder is increased. By increasing or decreasing the hydraulic pressure in the wheel cylinders in this way, the slip of the wheels is kept within an appropriate range.

If the drive wheels slip excessively during acceleration,
The hydraulic pressure is transmitted from the hydraulic pressure source of the acceleration slip control pressure increasing unit to the wheel cylinder of the brake provided on the drive wheel through the pressure increasing passage, the rotation of the drive wheel is suppressed, and the slip is reduced. When the slip decreases, the brake fluid is prevented from being supplied from the hydraulic pressure source to the wheel cylinders in the acceleration slip control pressure increasing unit, and the brake fluid in the wheel cylinders is rapidly reduced by the acceleration slip control pressure reducing unit. The fluid pressure is rapidly reduced by rapidly discharging the fluid. By increasing and decreasing the hydraulic pressure in the wheel cylinder in this way, the slip of the drive wheels is kept within an appropriate range.

In the brake fluid pressure control device according to the second aspect of the present invention, at the time of braking, the pressure-increasing on-off valve is opened, and the fluid pressure of the master cylinder is transmitted to the wheel cylinder to suppress wheel rotation. When the wheel slip is excessive, the pressure increasing on-off valve is closed and the pressure reducing on-off valve is opened.
The brake fluid in the wheel cylinder is rapidly discharged to the rapid decompression reservoir, and the hydraulic pressure in the wheel cylinder is rapidly reduced. The brake fluid that has flowed out is pumped up by the pressure reducing pump device and returned to the pressure increasing passage. In the decompression pump device, the decompression piston is reciprocated by the decompression piston drive device, whereby the brake fluid in the rapid decompression reservoir is pumped up through the suction valve and discharged through the discharge valve to the pressure boost passage. It When the wheel slip is reduced, the pressure reducing on-off valve is closed and the pressure increasing on-off valve is opened, so that the hydraulic pressure is transmitted to the wheel cylinder.

In the acceleration slip control, when the slip of the drive wheels increases beyond the proper range, the pressure increasing on-off valve is opened, the pressure reducing on-off valve is closed, and the pressure increasing pump device is operated to operate the master cylinder. The brake fluid of the connected main reservoir is supplied to the wheel cylinders of the drive wheels, the rotation of the drive wheels is suppressed, and the slip is reduced. When the slip on the drive wheels decreases, the pressure increase / decrease valves are closed and the pressure decrease / decrease valves are opened, causing the brake fluid in the wheel cylinders to rapidly flow out to the rapid pressure reduction reservoir, which alleviates the rotation of the drive wheels. To be done.

[0011]

As described above, according to the first aspect of the invention, the antilock control pressure increasing unit and the acceleration slip control pressure increasing unit are both provided in the pressure increasing passage, and the antilock control pressure reducing unit and the acceleration slip control are provided. Since all the pressure reducing units are provided in the pressure reducing passage, it is possible to obtain a brake fluid pressure control device having a simple structure as compared with the case where the pressure reducing units are provided in different pressure increasing passages and pressure reducing passages, respectively. In addition, a mechanism provided for decompressing or increasing the pressure of one of the antilock control and the acceleration slip control does not interfere with the other pressure increasing or depressurizing. Since it is not necessary to provide an electromagnetic opening / closing valve for increasing the pressure of the acceleration slip control in order to provide the reservoir for the sudden pressure reduction, it is possible to perform both the antilock control and the acceleration slip control in this respect as well, and a simple structure is provided. The brake fluid pressure control device of is obtained.

According to the second invention, in addition to the effect of the first invention, a pressure increasing pump device and a pressure reducing pump device are provided in the pressure increasing passage and the pressure reducing passage, respectively. Since the passage functions as a pump passage, the device can be configured more simply than when a pump device is provided by connecting the pump passage to the pressure increasing passage and the pressure reducing passage.
Further, the anti-lock control and the acceleration slip control can be performed only by providing two on-off valves that can be electrically opened and closed, one for increasing the pressure and one for reducing the pressure, which is advantageous in that the brake fluid pressure control device can be configured at low cost. can get.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The preferred embodiments of the present invention will be listed below, and related explanations will be given if necessary. (1) The brake fluid pressure control device according to claim 2, wherein at least the drive source of the pressure increasing piston drive device and the pressure reducing piston drive device are common. According to the device of this aspect, the number of constituent parts of the pressure increasing piston drive device and the pressure reducing piston drive device can be small, and the device can be made compact and inexpensive. (2) The pressure boosting piston drive device has a pressure boosting control pressure chamber formed on the side opposite to the pressure boosting pump chamber by the pressure boosting housing and the pressure boosting piston, and the pressure reducing piston drive device is A pressure reducing control pressure chamber formed on the opposite side of the pressure reducing pump chamber by the pressure reducing housing and the pressure reducing piston, and the pressure increasing piston drive device and the pressure reducing piston drive device are driven. A drive piston liquid-tightly and slidably fitted to the housing for driving, a drive chamber formed by the driving housing and the driving piston, and connected to the pressure increasing control pressure chamber and the pressure reducing control pressure chamber, The brake fluid pressure control device according to aspect 1, which shares a drive piston drive device that reciprocates the drive piston. In the device of this aspect, the drive piston is reciprocated by the drive piston drive device to increase or decrease the volume of the drive chamber, thereby increasing the volumes of the pressure increasing control pressure chamber and the pressure reducing control pressure chamber, The pressure-increasing piston and the pressure-reducing piston are moved to be reduced, and the brake fluid is sucked and discharged into the pressure-increasing pump chamber and the pressure-reducing pump chamber. The boosting piston driving device and the depressurizing piston driving device share a part, the number of parts is small, and the device can be made compact and inexpensive.
Moreover, both the pressure-increasing piston and the pressure-decreasing piston can operate at the same time, or only one of them can operate. In particular, even if the operation switching device is not provided, the necessary one operates when necessary. (3) The drive piston drive device includes an eccentric cam rotatably provided around one axis, a rotary drive motor for rotating the eccentric cam, and a biasing force of the drive piston in a direction to follow the eccentric cam. A brake fluid pressure control device according to aspect 2, including a biasing means. In the device of this aspect, the drive piston is forcibly moved to the side opposite to the side biased by the biasing means by the rotation of the eccentric cam.
The movement toward the side urged by the urging means is not forced, and the operation stroke of the drive piston can be arbitrarily changed as needed as long as it is within the maximum stroke range. At this time, the drive piston floats apart from the eccentric cam. Therefore, the operating strokes of the pressure-increasing piston and the pressure-decreasing piston can be arbitrarily changed as necessary,
In an extreme case, the rotary drive motor continues to rotate, but a situation may occur in which both the pressure increasing piston and the pressure reducing piston are stopped.

(4) For each of the plurality of drive wheels, the rotation of which is suppressed by the hydraulic pressure generated in one pressurizing chamber of the master cylinder, the pressure-increasing on-off valve and the pressure-decreasing on-off valve are provided and 4. The pressure increasing passage, the pressure reducing passage, the rapid pressure reducing reservoir, the pressure increasing pump device and the pressure reducing pump device are common to a plurality of drive wheels. The described brake fluid pressure control device. According to the apparatus of this aspect, the anti-lock control and the acceleration slip control are independently performed by opening / closing the pressure increasing / decreasing valve and the pressure reducing / opening valve independently for each of the plurality of drive wheels. Members other than the pressure increasing / decreasing on / off valve and the pressure reducing on / off valve are common, the number of parts is small, and a small and inexpensive brake fluid pressure control device can be obtained.

(5) Further, a bypass passage that connects the master cylinder and the wheel cylinder and bypasses the booster pump device, a bypass opening / closing valve provided in the bypass passage, and a bypass opening / closing valve. Is opened when the hydraulic pressure in the master cylinder exceeds a set value, and when the hydraulic pressure in the master cylinder decreases, it is closed at a lower speed than when it increased. And a wheel cylinder, the brake fluid supply preventing means at the time of antilock control for preventing the brake fluid from being supplied to the wheel cylinder from the master cylinder via the bypass opening / closing valve at the time of antilock control. Item 2, The brake fluid pressure control device according to any one of aspects 1 to 4.

(6) The opening / closing control device is provided on a control housing, a control piston liquid-tightly and slidably fitted in the control housing, and provided on one side of the control piston, To the master cylinder pressure chamber side, a speed control chamber provided on the other side of the control piston, and a fluid from the speed control chamber. The brake fluid pressure control device according to aspect 5, further comprising a fluid outflow / inflow means that causes the fluid to flow out at a flow rate lower than that at the time of outflow. (7) Aspect 6 in which the bypass opening / closing valve includes a valve element provided on the master cylinder pressure chamber side of the control piston and a valve seat provided at a connection port of the control housing to the wheel cylinder. The described brake fluid pressure control device.

(8) The fluid outflow / inflow means is provided in the rapid decompression reservoir connected to the speed control chamber by a reservoir passage and the reservoir passage, and brakes from the speed control chamber to the rapid decompression reservoir. Aspect 6 that includes a check valve that allows a flow of liquid but blocks a reverse flow, a connection passage that connects the speed control chamber and the master cylinder, and a throttle provided in the connection passage. The described brake fluid pressure control device.

(9) The fluid outflow / inflow means has a variable volume chamber in which a liquid is enclosed, the volume is decreased by the outflow of the liquid, and the volume is increased by the inflow, the variable volume chamber and the speed control chamber. A first liquid passage and a second liquid passage that are connected in parallel with each other, a throttle provided in the first liquid passage, and a second liquid passage, and the speed control chamber to the variable volume chamber. And a non-return valve that allows the flow of the liquid but prevents the flow in the reverse direction. (10) The fluid outflow / inflow means connects a gas chamber in which a gas is enclosed, the gas chamber and the speed control chamber, and a first gas passage and a second gas passage provided in parallel with each other. An embodiment including a throttle provided in the first gas passage and a check valve provided in the second gas passage, which allows the flow of gas from the speed control chamber to the gas chamber but blocks the flow in the opposite direction. The brake fluid pressure control device according to item 6.

According to the apparatus of the above two aspects, since the fluid outflow / inflow means controls the moving speed of the control piston by inflow / outflow of the fluid other than the brake fluid into / from the speed control chamber, the fluid outflow / inflow means. The brake fluid will not leak due to damage to the piping in the inflow means, and the situation in which the rotation of the wheels is not suppressed will not occur. Even if the control piston does not move due to a failure of the fluid outflow / inflow means, and the bypass opening / closing valve does not open or close, brake fluid is supplied to the wheel cylinders by the pressure increasing passages, and wheel rotation is suppressed. Of. Further, in the brake fluid pressure control device according to the ninth aspect, even if bubbles are generated in the liquid due to negative pressure in the speed control chamber and the variable volume chamber, the bubbles are mixed with the brake fluid to operate the brake. Will not be adversely affected.

(11) The bypass passage bypasses the pressure boosting pump device and the pressure boosting on-off valve, and the anti-lock control brake fluid supply preventing means and the bypass on-off valve of the bypass passage are provided. One of the aspects 5 to 10 including a check valve which is provided in a portion between the wheel cylinder and allows the flow of the brake fluid from the wheel cylinder to the bypass opening / closing valve but prevents the reverse flow of the brake fluid. Brake fluid pressure control device described in.

(12) The bypass passage bypasses the pressure increasing pump device to connect the master cylinder and the pressure increasing on-off valve, and the pressure increasing on-off valve prevents the brake fluid supply during the antilock control. 11. The brake fluid pressure control device according to any one of aspects 5 to 10 which functions as a means. The pressure-increasing on-off valve is closed during anti-lock control decompression, which prevents brake fluid from being supplied from the master cylinder to the wheel cylinders through the bypass on-off valve during depressurization, preventing the wheel cylinder pressure from decreasing. Absent.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments common to the first and second inventions will be described in detail with reference to the drawings. 1 in FIG.
Is a brake pedal as a brake operating member. In response to the depression operation of the brake pedal 10, hydraulic pressures of the same height are generated in two independent pressurizing chambers of the master cylinder 12. A main reservoir 14 is attached to the master cylinder 12 and supplies brake fluid to the master cylinder 12.

The hydraulic pressure generated in one pressurizing chamber of the master cylinder 12 is transmitted to the front wheel cylinder 20 of the brake of the left front wheel 18 by the liquid passage 16 and the liquid passage 2
2 is transmitted to the front wheel cylinder of the brake for the right front wheel (not shown). The hydraulic pressure generated in the other pressurizing chamber of the master cylinder 12 is transmitted to the rear wheel cylinder 28 of the brake of the left rear wheel 26 by the liquid passage 24, and is transmitted to the rear wheel cylinder 28 of the brake of the right rear wheel (not shown) by the liquid passage 30. Be transmitted to.

The left front wheel 18 is a non-driving wheel and the left rear wheel 26 is a driving wheel. The left and right front wheels are independently antilock-controlled, and the left and right rear wheels are independently antilock-controlled and accelerated. Slip controlled. Left front wheel 1
The anti-lock control mechanism provided for each of the right front wheel 8 and the right front wheel has the same configuration, and the left front wheel 18 will be representatively described below.

The liquid passage 16 has a normally open first electromagnetic on-off valve 34.
Is provided. A portion of the liquid passage 16 between the first electromagnetic on-off valve 34 and the front wheel cylinder 20 is connected to a rapid decompression reservoir 38 by a reservoir passage 36, and a normally closed second electromagnetic on-off valve 40 is provided. There is. The hydraulic pressure of the front wheel cylinder 20 is increased, decreased, or maintained by the combination of opening and closing of the first and second electromagnetic on-off valves 34 and 40.

The brake fluid discharged from the front wheel cylinder 20 to the rapid decompression reservoir 38 is pumped up by the pump 44 driven by the pump motor 42, and the pump passage 46 provides the first electromagnetic on-off valve 34 of the fluid passage 16. The part is returned to the part closer to the master cylinder 12 than the part. The pump 44 has two check valves 48 to prevent the reverse flow of the brake fluid to the rapid decompression reservoir 38.

The liquid passage 16 has a first electromagnetic opening / closing valve 34.
A bypass passage 50 for bypassing the valve is provided, and a check valve 52 is provided so that the brake fluid in the front wheel cylinder 20 is released when the brake is released.
It quickly returns to the master cylinder 12 from both the side and the bypass passage 50 side.

The rotational speeds of the left front wheel 16 and the right front wheel are
As shown for the left front wheel 16, it is detected by a rotation speed sensor 56, and the detection result is supplied to a vehicle speed calculation unit 58. The vehicle speed calculation unit 58 calculates the wheel speed, the wheel acceleration, the vehicle body speed, etc., and supplies them to the antilock control unit 60. The antilock control unit 60 is mainly composed of a computer, and controls the first and second electromagnetic on-off valves 34 and 40 and the pump motor 42 of the left front wheel system and the right front wheel system to perform antilock control. The antilock control unit 60 is also supplied with a detection signal of a brake switch 62 for detecting depression of the brake pedal 10.

The left rear wheel 26 and the right rear wheel are respectively provided with an antilock control mechanism and an acceleration slip control mechanism of the same structure, and the left rear wheel 26 will be representatively described. A normally-opened solenoid valve 64 for increasing pressure is provided in the liquid passage 24 for transmitting the hydraulic pressure of the master cylinder 12 to the rear wheel cylinder 28. The master cylinder 12 and the rear wheel cylinder 28 are also connected by a liquid passage 68 parallel to the liquid passage 24. Hereinafter, the liquid passage 24 will be referred to as the pressure increasing passage 24, and the liquid passage 68 will be referred to as the pressure reducing passage 68. A normally closed decompression electromagnetic on-off valve 70 is provided in the decompression passage 68, and a rapid decompression reservoir 74 is connected to a portion of the decompression passage 68 closer to the master cylinder 12 than the decompression electromagnetic on-off valve 70 by a reservoir passage 72. ing.

A pressure increasing pump device 76 is provided between the master cylinder 12 of the pressure increasing passage 24 and a portion where the pressure increasing electromagnetic on-off valve 64 is provided. Booster pump device 7
6 has a pressure-increasing piston 80 fitted in a pressure-increasing housing 78 so as to be liquid-tight and slidable, and a pressure-increasing pump chamber 82 formed by the pressure-increasing housing 78 and the pressure-increasing piston 80 is increased. It is connected to the pressure passage 24. Although the flow of the brake fluid from the master cylinder 12 side to the pressure increasing pump chamber 82 side is allowed to the master cylinder 12 side from the portion of the pressure increasing passage 24 to which the pressure increasing pump chamber 82 is connected, the reverse flow does not occur. A suction valve 84 for blocking is provided, and a portion between the pressure-increasing passage 24 is connected to the pressure-increasing pump chamber 82 of the pressure-increasing passage 24 and a portion between the pressure-increasing electromagnetic on-off valve 64. Discharge valve 8 that allows the flow of brake fluid to the side but blocks the reverse flow
6 is provided.

A pressure increasing control pressure chamber 90 is formed on the opposite side of the pressure increasing pump chamber 82 by the pressure increasing housing 78 and the pressure increasing piston 80, and a drive formed by a drive housing 92 and a drive piston 94. It is connected to the chamber 96. The drive piston 94 is fluid-tightly and slidably fitted into the drive housing 92 to form a drive chamber 96, and is an elastic member which is a kind of urging means (not shown) disposed in the drive chamber 96. Is urged in the direction of coming into contact with the eccentric cam 98. Eccentric cam 98
Has a circular cross section, and is eccentrically attached to the shaft 100.

When the shaft 100 is rotated by a drive motor (not shown) to rotate the eccentric cam 98, the drive piston 94 is pushed by the eccentric cam 98 and urged by a spring to reciprocate. If the drive piston 94 is moved in a direction that reduces the volume of the drive chamber 96, the liquid in the drive chamber 96 flows into the pressure increasing control pressure chamber 90, and the pressure increasing piston 80 is moved to the pressure increasing pump chamber 82 side. Then, the brake fluid in the pressure increasing pump chamber 82 is discharged. Drive piston 94 is drive chamber 96
If the volume is increased, the brake fluid is sucked into the pressure increasing pump chamber 82, and the pressure increasing piston 80
Is moved to the pressure increasing control pressure chamber 90 side, liquid is allowed to flow into the drive chamber 96, and the drive piston 94 is allowed to move following the eccentric cam 98. The eccentric cam 98, a drive motor and a spring (not shown) constitute a drive piston drive device 102, and a pressure increasing control pressure chamber 90 and a drive chamber 9 are provided.
6, together with the drive piston 94 and the drive housing 92, constitutes a pressure boosting piston drive device 104.

In the decompression passage 68, the decompression pump device 10 is provided.
6 is connected. The depressurizing pump device 106 has a depressurizing piston 110 that is liquid-tightly and slidably fitted in a depressurizing housing 108, and is formed by the depressurizing housing 108 and the depressurizing piston 110. The chamber 114 is connected to the pressure reducing passage 68. The rapid decompression reservoir 74 is located closer to the rapid decompression reservoir 74 than the portion of the decompression passage 68 to which the decompression pump chamber 114 is connected.
Side is provided with an intake valve 116 that allows the flow of the brake fluid from the pressure reducing pump chamber 114 side to the reverse direction but blocks the flow in the opposite direction, and the master cylinder from the portion of the pressure reducing passage 68 to which the pressure reducing pump chamber 114 is connected. In the side portion, the discharge valve 1 that allows the flow of the brake fluid from the pressure reducing pump chamber 114 side to the master cylinder 12 side, but prevents the flow in the opposite direction.
18 is provided. Between the portion of the pressure reducing passage 68 to which the reservoir passage 72 is connected and the pressure reducing electromagnetic opening / closing valve 70, the pressure reducing electromagnetic opening / closing valve 70 is connected to the rapid pressure reducing reservoir 7
A check valve 120 is provided which allows the flow of the brake fluid to the No. 4 but prevents the flow in the opposite direction. Although the pressure increasing housing 78, the drive housing 92, and the pressure reducing housing 108 are illustrated as separate bodies in FIG. 1, they are integrally configured and the pressure increasing control pressure chamber 9 is formed.
0, the drive chamber 96, and the pressure-reducing control pressure chamber 122, which will be described later, communicate with each other as long as the stroke ends of the pressure-increasing piston 80 and the pressure-reducing piston 110 can be defined.

A decompression control pressure chamber 122 is formed on the opposite side of the decompression pump chamber 114 by the decompression housing 108 and the decompression piston 110, and is connected to the drive chamber 96. Therefore, when the drive piston 94 is reciprocated, the pressure reducing piston 110 is moved similarly to the pressure increasing piston 80, and the pressure reducing pump chamber 11 is moved.
4, the brake fluid is sucked from the sudden decompression reservoir 74,
It is discharged to the master cylinder 12 side. The drive piston drive device 102, the drive piston 94, the drive chamber 96, and the drive housing 92 are shared with the pressure increasing piston drive device 104, and these shared members together with the pressure reducing control pressure chamber 122 form the pressure reducing piston drive device 124. I am configuring.

The pressure increasing passage 24 is provided with a bypass passage 130 for bypassing the suction valve 84 and a relief valve 132. The master cylinder 12 and the rear wheel cylinder 28 are also provided with a pressure increasing pump device 7.
6 and the pressure-increasing electromagnetic on-off valve 64 are connected by a bypass passage 136. This bypass passage 1
On-off valve 138 for bypass (see FIG. 2) in the middle of 36
And a pilot-type blockage delay valve 142 including an opening / closing control device 140 for controlling opening / closing of the bypass opening / closing valve 138.
The bypass passage 136 is divided into a master cylinder side passage 144 and a wheel cylinder side passage 146.

As shown in FIG. 2, the opening / closing control device 140 has a control piston 152 fitted in a control housing 150 so as to be liquid-tight and slidable. Control piston 1
A master cylinder pressure chamber 154 is formed on one side of the port 52, and the port 156 and the master cylinder side passage 14 are formed.
4 is connected to the master cylinder 12 by
Port 158 and the wheel cylinder side passage 146
It is connected to the rear wheel cylinder 28 by.
As shown in FIG. 1, the wheel cylinder side passage 146 is provided with a check valve 160 that allows the flow of the brake fluid from the rear wheel cylinder 28 to the master cylinder pressure chamber 154, but blocks the reverse flow. ing.

A valve element 164 is projectingly provided on an end surface of the control piston 152 on the master cylinder pressure chamber 154 side. The valve element 164 has a protrusion 16 provided on the control piston 152.
6 has a rubber sheet 168 attached, and port 1
A bypass opening / closing valve 138 is configured together with a valve seat 170 configured by the open end of 58. On-off valve for bypass 1
Since the rubber sheet 168 is closed by bringing the rubber sheet 168 into close contact with the opening rim of the port 158, the valve element 164 is closed.
The bypass opening / closing valve 138 is closed even if the axes of the control piston 152 and the control piston 152 deviate from each other.

A speed control chamber 172 is formed on the other side of the control piston 152, and is connected to the rapid decompression reservoir 74 by a port 174 and a reservoir passage 176 formed in the control housing 150. In the reservoir passage 176, the rapid decompression reservoir 7 from the speed control chamber 172 is provided.
4 is provided with a check valve 178 (see FIG. 1) that allows the flow of brake fluid to the No. 4 but prevents the flow in the opposite direction.
The speed control chamber 172 is also connected to the master cylinder side passage 144 by a port 180 formed in the control housing 150 and a connection passage 182, and the connection passage 182 is provided with a throttle 184.

The speed control chamber 172 is provided with a spring 188 as an elastic member, which is a kind of biasing means, and biases the control piston 152 toward the master cylinder pressure chamber 154 side. As a result, the valve element 164 causes the valve seat 17 to be in the non-braking state.
The bypass opening / closing valve 138 is closed. The bypass opening / closing valve 138 is supplied with brake fluid to the master cylinder pressure chamber 154, and the control piston 152
It is opened by the master cylinder pressure acting on
This valve opening pressure is set to 0.1 MPa. The bypass opening / closing valve 138 is also opened by the wheel cylinder pressure acting from the wheel cylinder side passage 146 side to the valve element 164 in a direction away from the valve seat 170.
This valve opening pressure is set to 4 MPa.

The respective rotational speeds of the left rear wheel 26 and the right rear wheel are
As shown for the left rear wheel 26, it is detected by the rotation speed sensor 200 and supplied to the vehicle speed calculation unit 58. The vehicle speed calculation unit 58 is connected to the anti-lock control unit 60 and the acceleration slip control unit 202. The acceleration slip control unit 202 is mainly composed of a computer, and the antilock control unit 60 and the acceleration slip control unit 202 include a motor for rotating the pressure increasing electromagnetic on-off valve 64, the pressure reducing electromagnetic on-off valve 70 and the eccentric cam 98. They are respectively controlled to perform antilock control and acceleration slip control.

Next, the operation will be described. First, the left front wheel system will be described by taking the left front wheel 18 as an example. When the brake pedal 10 is not depressed, the first electromagnetic on-off valve 34 and the second electromagnetic on-off valve 40 are in the state shown in FIG. 1, and the front wheel cylinder 20 is the master cylinder 1
Connected to 2. When the brake pedal 10 is depressed, the hydraulic pressure generated in the pressurizing chamber of the master cylinder 12 is transmitted to the front wheel cylinder 20 and the rotation of the wheels is suppressed.

When the stepping force of the brake pedal 10 is excessive with respect to the friction coefficient of the road surface and the slip of the left front wheel 18 increases beyond the proper range, the first solenoid opening / closing valve 34 is closed and the second solenoid valve 34 is closed. The solenoid valve 40 is opened and the wheel cylinder pressure is reduced. As a result, if the slip is reduced, the second solenoid opening / closing valve 40 is closed to hold the wheel cylinder pressure, and if the slip is recovered, the first solenoid opening / closing 34 is opened and the wheel cylinder pressure is increased. The wheel cylinder pressure is increased, decreased, or held so that the slip of the left front wheel 18 is kept in an appropriate range.

The left and right rear wheel system will be described by taking the left rear wheel 26 as an example. When the brake pedal 10 is not depressed and the acceleration slip control is not performed, the pressure increasing electromagnetic on-off valve 64 is opened, the pressure reducing electromagnetic on-off valve 70 is closed, and the bypass on-off valve 138 is also closed. Has been.

When the brake pedal 10 is depressed, the hydraulic pressure generated in the pressurizing chamber of the master cylinder 12 passes through the pressure increasing passage 24 through the intake valve 84, the discharge valve 86, the electromagnetic pressure increasing / closing valve 64, and the rear wheel cylinder 28. The rotation of the left rear wheel 26 is suppressed. At this time, the brake fluid is supplied to the master cylinder pressure chamber 154 of the bypass opening / closing valve 138, and the control piston 152 is retracted against the biasing force of the spring 188. This retreat is due to the speed control room 1
The brake fluid in 72 is discharged to the rapid decompression reservoir 74 to be allowed, the valve element 164 is quickly separated from the valve seat 170, and the bypass opening / closing valve 138 is opened. In this case, since the hydraulic pressure in the master cylinder pressure chamber 154 is high, the check valve 160 in the wheel cylinder side passage 146 is not opened and the brake fluid does not flow out from the rear wheel cylinder 28. The height of the left rear wheel 26 is suppressed to a height corresponding to the stepping force of the left rear wheel 26.

When the depression of the brake pedal 10 is released, the master cylinder pressure is reduced, and the hydraulic pressure in the master cylinder pressure chamber 154 of the opening / closing control device 140 is reduced. for that reason,
The wheel cylinder pressure becomes higher, the brake fluid in the rear wheel cylinder 28 returns to the master cylinder 12 through the check valve 160 and the master cylinder pressure chamber 154, and the wheel cylinder pressure corresponds to the depression force of the brake pedal 10. Lowered to height.

When the hydraulic pressure in the master cylinder pressure chamber 154 decreases, the control piston 152 is urged by the spring 188 to move forward. This forward movement is allowed by the brake fluid being supplied from the master cylinder 12 to the speed control chamber 172 via the throttle 184. However, if the brake pedal 10 is only released and not released, the master cylinder 12 is released. There is a master cylinder pressure higher than the valve opening pressure in the pressure chamber 154, and the bypass opening / closing valve 138 cannot be closed.

When the depression of the brake pedal 10 is released, similarly, the brake fluid in the rear wheel cylinder 28 returns to the master cylinder 12 through the check valve 160 and the master cylinder pressure chamber 154, and the braking is released. . Due to the decrease in hydraulic pressure in the master cylinder pressure chamber 154, the control piston 15
2 is urged by the spring 188 and the valve element 164 is moved forward in a direction to be seated on the valve seat 170. However, since the brake fluid is supplied to the speed control chamber 172 through the throttle 184 at a small flow rate, the control piston 152 The forward speed is lower than the reverse speed, and the brake fluid in the rear wheel cylinder 28 can return to the master cylinder 12 before the valve element 164 is seated on the valve seat 170 and the bypass opening / closing valve 138 is closed.

Brake pedal 1 against the friction coefficient of the road surface
When the stepping force of 0 is excessive and the slip of the left rear wheel 26 increases, the pressure increasing electromagnetic opening / closing valve 64 is closed and the pressure reducing electromagnetic opening / closing valve 70 is opened, and the rear wheel cylinder 2
The brake fluid in 8 rapidly flows out to the rapid decompression reservoir 74 at a large flow rate. Further, the eccentric cam 98 is rotated simultaneously with the start of the antilock control, and the drive piston 94 is reciprocated.

Therefore, the brake fluid that has flown out to the sudden pressure reducing reservoir 74 is pumped up by the pressure reducing pump device 106 and returned to the pressure increasing passage 24. Since the eccentric cam 98 is shared, when the pressure reducing piston 110 is moved, the pressure increasing piston 80 is also moved and the brake fluid is supplied to the pressure increasing pump chamber 82. However, the solenoid valve for increasing pressure 64 is closed and the rear wheel cylinder 28
Since the brake fluid cannot be discharged to the pressure-increasing piston 80, the pressure-increasing piston 80 cannot discharge the brake fluid sucked into the pressure-increasing pump chamber 82, and stops while being moved to the pressure-increasing control pressure chamber 90 side. . Only the decompression pump device 106 operates to pump up the brake fluid from the rapid decompression reservoir 74. At this time, the on-off valve 138 for bypass
However, since the check valve 160 is provided in the wheel cylinder side passage 146, the master cylinder 12
The brake fluid is not supplied to the rear wheel cylinder 28 through the bypass opening / closing valve 138, and the wheel cylinder pressure is reduced.

Left rear wheel 2 due to reduction of wheel cylinder pressure
When the slip of 6 is reduced, the pressure reducing electromagnetic on-off valve 70 is closed and the wheel cylinder pressure is maintained. in this case,
While the brake fluid is in the rapid decompression reservoir 74, the brake fluid is pumped up from the rapid decompression reservoir 74 by the decompression pump device 106 and returned to the pressure increase passage 24. When there is no brake fluid in the rapid decompression reservoir 74, the decompression piston 110 stops moving while moving to the decompression pump chamber 114 side, and only the pressure boosting piston 80 reciprocates to supply the brake fluid to the pressure boosting pump chamber 82. Although it sucks and discharges, since the pressure-increasing electromagnetic on-off valve 64 is closed, the discharged brake fluid is returned from the relief valve 132 to the master cylinder 12 side. The brake fluid can be circulated through the suction valve 84, the pressure increasing pump chamber 82, and the relief valve 132.

When the slip of the left rear wheel 26 decreases due to the reduction and maintenance of the wheel cylinder pressure, the pressure reducing solenoid on-off valve 7
0 is closed and the solenoid valve 64 for increasing pressure is opened to supply brake fluid to the rear wheel cylinder 28.
The wheel cylinder pressure is increased. At the time of increasing the pressure, even if the brake fluid remains in the rapid pressure reducing reservoir 74, the pressure reducing pump device 106 does not perform the pumping. When the drive piston 94 is retracted at the time of increasing the pressure, the hydraulic pressure of the portion of the pressure increasing passage 24 connected to the pressure increasing pump chamber 82 is connected to the pressure reducing pump chamber 114 of the pressure reducing passage 68. Since it is higher than the hydraulic pressure of the part where
While the pressure reducing piston 110 does not move backward while the pressure reducing piston 110 can move backward, the brake fluid is sucked into the pressure increasing pump chamber 82 prior to the suction into the pressure reducing pump chamber 114. The reason is that the maximum volume of the pressure boosting pump chamber 82 is made slightly larger than the maximum volume of the drive chamber 96, so that the pressure reducing piston 110 does not move backward. However, the maximum volume of the drive chamber 96 is made larger than the maximum volume of the pressure boosting pump chamber 82, and pumping is performed by the pressure reducing pump device 106 as long as the brake fluid remains in the rapid pressure reducing reservoir 74 even when the pressure is increased. It is also possible to be made public.

During the antilock control, if the depression of the brake pedal 10 is released while the wheel cylinder pressure is being increased, the master cylinder pressure is lowered and the wheel cylinder pressure becomes higher than the master cylinder pressure. Therefore, the brake fluid in the rear wheel cylinder 28 returns to the master cylinder 12 through the check valve 160 and the bypass opening / closing valve 138, and the wheel cylinder pressure is reduced.

When the brake pedal 10 is released,
Alternatively, if the antilock control ending condition is satisfied, such as when the vehicle speed becomes less than or equal to the set speed, the solenoid valve 64 for increasing pressure is opened.
Is opened and the decompression electromagnetic on-off valve 70 is closed. At the end of the anti-lock control, the wheel cylinder pressure is normally maintained, and all the brake fluid discharged from the rear wheel cylinder 28 to the rapid depressurization reservoir 74 is pumped up by the depressurization pump device 106 and the master cylinder. The brake fluid in the master cylinder 12 does not run short.

When the anti-lock control is released by releasing the brake pedal 10, the brake fluid in the rear wheel cylinder 28 returns to the master cylinder 12 before the bypass opening / closing valve 138 is closed. Further, although the depression of the brake pedal 10 is not released, when the antilock control is terminated due to the decrease in the vehicle speed, the solenoid valve for pressure increase 64 is opened and the brake fluid is transferred from the master cylinder 12 to the rear wheel cylinder 26. Is supplied, the wheel cylinder pressure corresponding to the depression force of the brake pedal 10 is obtained.

The acceleration slip control will be described. When the left rear wheel 26, which is a driving wheel, increases in slip when the vehicle starts or accelerates, the acceleration slip control unit 202 operates the pressure increasing pump device 76 to activate the rear wheel cylinder 28.
The brake fluid is supplied to the vehicle and the rotation of the left rear wheel 26 is suppressed. At the start of the acceleration slip control, the motor is started and the eccentric cam 98 is rotated, whereby the pressure increasing piston 80 pumps out the brake fluid from the main reservoir 14 via the master cylinder 12 and supplies it to the rear wheel cylinder 28. Since there is no brake fluid in the rapid decompression reservoir 74, the decompression piston 110 stops while moving toward the decompression pump chamber 114 side, and only the pressure boosting piston 80 reciprocates to supply the brake fluid to the rear wheel cylinder 28. Supply.

Since the brake pedal 10 is not depressed and the master cylinder pressure is not generated, in the opening / closing control device 140, the control piston 152 causes the spring 1 to move.
The bypass opening / closing valve 138 is closed by being biased by 88. If the wheel cylinder pressure increases due to the supply of the brake fluid to the rear wheel cylinder 28, the valve element 164
The hydraulic pressure in the direction of separating the valve seat 170 from the valve seat 170 increases. If the wheel cylinder pressure reaches the valve opening pressure of the bypass opening / closing valve 138, the control piston 152 causes the spring 18 to move.
The bypass opening / closing valve 1 is retracted against the biasing force of 8
38 is opened. The bypass opening / closing valve 138 acts as a relief valve, and in this embodiment, the valve opening pressure is set to 4 MPa, and a sufficient wheel cylinder pressure is obtained for acceleration slip control.

When the slip of the left rear wheel 26 decreases, the pressure-increasing electromagnetic on-off valve 64 is closed and the wheel cylinder pressure is maintained. In this case, as in the case of the antilock control, if there is brake fluid in the rapid pressure reducing reservoir 74, the pressure reducing pump device 106 pumps out the brake fluid and returns it to the pressure boosting passage 24. At this time, the pressure increasing piston 80 of the pressure increasing pump device 76 is stopped at the pressure increasing control pressure chamber 90 side.
If there is no brake fluid in the rapid decompression reservoir 74, the pressure boosting piston 80 reciprocates, and the brake fluid is sucked into the suction valve 84,
The pressure increasing pump chamber 82 and the relief valve 132 can be circulated.

When the slip of the left rear wheel 26 is further reduced, the pressure reducing electromagnetic on-off valve 70 is opened and the rear wheel cylinder 2 is opened.
The brake fluid in 8 is made to flow out to the rapid decompression reservoir 74 at a large flow rate. The brake fluid that has flown into the rapid decompression reservoir 74 is pumped out by the reciprocating movement of the decompression piston 110 and returned to the main reservoir 14. At this time, since the pressure-increasing electromagnetic on-off valve 64 is closed, the pressure-increasing piston 8
0 is the same as in the antilock control, and the pressure increasing control pressure chamber 9
It remains stopped on the 0 side.

If the conditions for terminating the acceleration slip control are satisfied, such as when the vehicle speed exceeds the set value or the accelerator pedal is released, the solenoid valve 64 for increasing pressure is closed and the pressure is reduced during the set time. Solenoid valve 70 for
Is opened, the brake fluid in the rear wheel cylinder 28 is caused to flow out to the rapid decompression reservoir 74, and is pumped out by the decompression pump device 106 so that the main reservoir 14 is opened.
Is returned to. The brake fluid in the wheel cylinder 28 is discharged to the rapid decompression reservoir 74 and the main reservoir 1
After a lapse of a time sufficient to return to 4, the pressure reducing pump device 106 and the pressure increasing pump device 76 are stopped,
The pressure increasing electromagnetic on-off valve 64 is opened and the pressure reducing electromagnetic on-off valve 70 is closed, and the acceleration slip control ends. At this time, the pressure increasing piston 80 is stopped in a state where the brake fluid is sucked into the pressure increasing pump chamber 82, and the pressure reducing piston 110 is stopped in a state where the brake fluid is pushed out from the pressure reducing pump chamber 114. The driving piston driving device 102 is kept in that state until it is actuated. If the brake pedal 10 is depressed before the set time elapses, the pressure reducing electromagnetic on-off valve 70 is closed and the pressure increasing electromagnetic on-off valve 64 is opened, and the brake fluid is supplied to the rear wheel cylinder 28.

As described above, in this embodiment, the pressure increasing piston drive device 104 and the pressure reducing piston drive device 1 are used.
Numeral 24 moves the drive piston 94 by the eccentric cam 98 and the biasing means to increase or decrease the volumes of the drive chamber 96, the pressure increasing control pressure chamber 90, and the pressure reducing control pressure chamber 122, thereby increasing the pressure increasing piston 80. The pressure reducing piston 110 is indirectly driven by the drive piston 94 via a fluid. Therefore, the drive piston 94 can be biased by the biasing means so as not to move in a direction following the eccentric cam 98, and even if the pressure boosting piston 80 and the pressure reducing piston 110 do not move, the drive piston 94 does not move. 9
4 cannot be moved forcibly and damaged. Also,
Since the pressure increasing piston 80 and the pressure reducing piston 110 are indirectly driven by the drive piston 94 through the fluid,
Even if one of the pressure boosting piston 80 and the pressure reducing piston 110 does not move, the other can move. The one that is easier to move will move. This advantage is obtained as long as the pressure increasing piston 80 and the pressure reducing piston 110 are driven by the drive piston 94 through the fluid, and the drive piston 94 is forcibly reciprocated by a mechanical drive device including a crank. It doesn't change even if it is given.

FIG. 3 shows another pump device. In this pump device, the pressure increasing piston drive device 208 of the pressure increasing pump device 206 and the pressure reducing piston drive device 212 of the pressure reducing pump device 210 bring the eccentric cam 214 into contact with the pressure increasing piston 216 and the pressure reducing piston 218. It is configured to be moved directly.

The pressure boosting piston 216 is fluid-tightly and slidably fitted in the pressure boosting housing 220, and the pressure boosting pump chamber 222 formed by the pressure boosting piston 216 and the pressure boosting housing 220 is provided in the pressure boosting passage 24. It is connected. In addition, the pressure increasing piston 216 is provided in the pressure increasing pump chamber 22.
A spring 224 as an elastic member, which is a kind of urging means disposed in the second member 2, urges the eccentric cam 214 in a contacting direction. The eccentric cam 214 is eccentrically attached to the shaft 226, and when the shaft 226 is rotated by a drive motor (not shown), the boosting piston 2
16 is moved following the eccentric cam 214, and the brake fluid is sucked into the pressure increasing pump chamber 222 and discharged.

Similarly, the depressurizing piston 218 is fitted in the depressurizing housing 230 in a liquid-tight and slidable manner, the depressurizing pump chamber 232 is connected to the depressurizing passage 68, and the depressurizing pump chamber 232 is provided in the depressurizing pump chamber 232. A spring 234 as an elastic member, which is a kind of urging means provided, urges the pressure reducing piston 218 in a direction of contacting the eccentric cam 214. In the present embodiment, the pressure increasing piston drive device 208 and the pressure reducing piston drive device 212 share the eccentric cam 214 and the rotary drive motor that rotates the eccentric cam 214, and the shared member and the spring 224.
Compose the pressure increasing piston drive device 208, and the common member and the spring 234 form the pressure reducing piston drive device 21.
Make up 2.

Since the operation during normal braking is the same as that of the above-mentioned embodiment, its explanation is omitted. At the time of antilock control, the eccentric cam 214 is rotated at the same time as the control is started. When the wheel cylinder pressure is reduced, the pressure increasing electromagnetic on-off valve 64 is closed and the pressure reducing electromagnetic on-off valve 70 is opened, and the brake fluid is supplied to the rear wheel. It is made to flow from the cylinder 28 to the sudden pressure reducing reservoir 74, is pumped up, and is returned to the pressure increasing passage 24. At this time, the pressure-increasing piston 216 is reciprocated following the eccentric cam 214, and the brake fluid is sucked into the pressure-increasing pump chamber 222. However, since the pressure-increasing electromagnetic on-off valve 64 is closed, the rear wheel cylinder Two
8 cannot be discharged to the pressure increasing passage 24 from the relief valve 132. When the wheel cylinder pressure is maintained, the solenoid valve for increasing pressure 64 and the solenoid valve for decreasing pressure 70
Is closed, and while there is brake fluid in the rapid decompression reservoir 74, it is pumped up by the decompression pump device 210 and returned to the pressure increase passage 24, and when there is no more, the decompression piston 218 moves to the decompression pump chamber 232 side. While in the stopped state, the pressure boosting piston 216 is forcibly moved by the eccentric cam 214, so that the brake fluid is sucked into the pressure boosting pump chamber 222 and discharged from the relief valve 132 to the pressure boosting passage 24. When the wheel cylinder pressure is increased, the pressure increasing electromagnetic on-off valve 64 is opened and the pressure reducing electromagnetic on-off valve 70 is closed, and the pressure reducing piston 218 is used for the rapid pressure reducing reservoir 74.
If there is brake fluid, the fluid is reciprocated to pump up the brake fluid and return it to the pressure boosting passage 24. The pressure increasing piston 216 sucks the brake fluid into the pressure increasing pump chamber 222 and discharges it to the rear wheel cylinder 28.

During the acceleration slip control, the eccentric cam 214 is rotated at the same time as the control is started, and the pressure boosting piston 2 is rotated.
16 is moved to supply brake fluid to the rear wheel cylinder 28. At this time, the pressure reducing piston 218
If there is brake fluid in the rapid decompression reservoir 74, it is pumped up and returned to the pressure boosting passage 24, and if not, the decompression pump chamber 23.
Stop moving while moving to the 2 side. The operation for holding and reducing the wheel cylinder pressure is the same as for antilock control.
Description is omitted.

In each of the above-mentioned embodiments, the pressure-increasing on-off valve, the pressure-decreasing on-off valve, the pressure-increasing passage, the pressure-reducing passage, the pressure-increasing pump device, the pressure-reducing pump device, and the agitation device for each of the left and right rear wheels, which are the drive wheels, Although a decompression reservoir, a bypass on-off valve, and an on-off control device were provided, as shown in FIG. 4, for the left and right rear wheels 240 and 242, which are drive wheels, a pressure increase passage 244, a pressure reduction passage 246, and a pressure increasing passage are provided. Pump device 248,
The depressurizing pump device 250, the rapid depressurizing reservoir 252, and the pilot-type blockage delay valve 254 may be shared. The pressure increasing pump device 248 and the pressure reducing pump device 250
1 and the pilot-type blockage delay valve 254, respectively.
The configuration is similar to that of the embodiment shown in FIG.

The hydraulic pressure generated in one of the pressurizing chambers of the master cylinder 12 is divided into two pressure increasing passages 262 and 264 branched from the pressure increasing passage 244 so that the left and right rear wheels 240,
242 rear wheel cylinders 266, 2 for each brake
68 is transmitted. The branch pressure-increasing passages 262 and 264 are provided with pressure-increasing electromagnetic on-off valves 270 and 272, respectively. The master cylinder 12 also includes a pressure reducing passage 246 and two branch pressure reducing passages 276 and 278 branched from the pressure reducing passage 246.
6, 268, and branch pressure reducing passages 276, 278 are provided with pressure reducing electromagnetic on-off valves 280, 282, respectively. Furthermore, rear wheel cylinders 266, 268
Are connected to the master cylinder pressure chamber of the opening / closing control device for the pilot-type blockage delay valve 254 by the wheel cylinder side passages 288 and 290 provided with check valves 284 and 286, respectively.

The boosting pump device 248 and the depressurizing pump device 250 are common to the left and right rear wheels 240 and 242, and are activated when antilock control is started for one rear wheel, but provided for the left rear wheel 240. The pressure increasing solenoid on-off valve 270, the pressure reducing solenoid on-off valve 280,
Solenoid valve 27 for increasing pressure provided for the right rear wheel 242
2. Since the pressure reducing electromagnetic on-off valve 282 is opened and closed independently of each other, the left and right rear wheels 240 and 242 are independently subjected to antilock control and acceleration slip control.

During the acceleration slip control, for example, when one of the rear wheels does not have a large slip and the acceleration slip control is not necessary, the acceleration slip control is started for the other rear wheel at the same time. The pressure-increasing electromagnetic on-off valve provided for the rear wheel is closed to prevent the rotation of the rear wheel that is not excessively slipped from being suppressed.

In each of the above embodiments, the control piston of the opening / closing control device is allowed to move by the inflow and outflow of the brake fluid into the speed control chamber, but a fluid different from the brake fluid is used. May be. For example, air is used in the opening / closing control device 300 of the pilot-type blockage delay valve 298 shown in FIGS. 5 and 6. The control piston 302 has a stepped shape, and the stepped cylinder bore 306 formed in the control housing 304 of the opening / closing control device 300 is kept liquid-tight by the seal member 308 and airtight by the seal member 310. Are slidably fitted together. Thereby, the large diameter portion 31 of the control piston 302
2 and the housing 304, the master cylinder pressure chamber 3
14 and the atmospheric pressure chamber 316 are formed, and the small diameter portion 318 and the housing 304 form a speed control chamber 320.

The master cylinder pressure chamber 314 has a port 32
2 and the master cylinder side passage 326 forming the bypass passage 324, the port 328 and the wheel cylinder side passage 3 are connected to the master cylinder 12.
It is connected to the pressure increasing electromagnetic on-off valve 64 by 30.
The large diameter portion 312 of the control piston 302 holds the valve element 334 of the bypass opening / closing valve 332. The valve 334 is
The shaft portion 336 is provided at both ends of the shaft portion 336 having a circular cross section, respectively.
The engaging portion 338 having a larger diameter and the ball 340 are provided, and the engaging portion 338 and the shaft portion 336 are radially arranged in the stepped fitting hole 342 formed in the large diameter portion 312. They are fitted with each other leaving a gap, and can be slightly moved in the radial direction. Further, the ball 340 is biased in a direction away from the large diameter portion 312 by a spring 344 arranged between the ball 340 and the large diameter portion 312.

A valve seat 346 is formed at the open end of the port 328 and constitutes a bypass opening / closing valve 332 together with the valve element 334. In addition, a thin groove 348 is formed in the valve seat 346, and even when the bypass opening / closing valve 332 is closed, the master cylinder pressure chamber 31 is discharged from the wheel cylinder side passage 330.
The brake fluid is allowed to flow into the valve 4 while being throttled. Further, the control piston 302 is biased in a direction in which the valve element 334 is seated on the valve seat 346 by a spring 350 as an elastic member which is a kind of biasing means arranged in the atmospheric pressure chamber 316.

A gas chamber 354 is formed in the large diameter portion 312 of the control piston 302, and the first gas passages 35 parallel to each other are formed.
6, connected to the speed control chamber 320 by the second gas passage 358. A throttle 360 is provided in the first gas air passage 356 and a check valve 362 is provided in the second gas passage 358 to allow the flow of air from the speed control chamber 320 to the gas chamber 354, but in the opposite direction. The flow is designed to stop.

In this embodiment, the brake pedal 10
When is depressed and hydraulic pressure is generated in the pressurizing chamber of the master cylinder 12, brake fluid is supplied to the master cylinder pressure chamber 314, and the control piston 302 is retracted against the biasing force of the spring 350. The retreat of the control piston 302 is allowed because the air in the speed control chamber 320 flows into the gas chamber 354 while compressing the air in the gas chamber 354 from both the throttle 360 side and the check valve 362 side. . Also, when the control piston 302 retracts, the large diameter portion 312
Engages with the engagement portion 338 of the valve element 334 to separate the valve element 334 from the valve seat 346, and the bypass opening / closing valve 332 is opened.

If the depression of the brake pedal 10 is released during normal braking, the hydraulic pressure in the master cylinder pressure chamber 314 decreases, and the brake fluid in the rear wheel cylinder 28 is released from the pressure increasing solenoid on-off valve 64 and the bypass valve. It returns to the master cylinder 12 through the on-off valve 332, the master cylinder pressure chamber 314, and the wheel cylinder pressure is reduced to a height corresponding to the stepping force of the brake pedal 10.

When the brake pedal 10 is released, the hydraulic pressure in the master cylinder pressure chamber 314 decreases.
The control piston 302 is urged by a spring 350 to move forward. This advance is allowed by the air in the gas chamber 354 flowing out to the speed control chamber 320 through the throttle 360. However, since the outflow amount is throttled by the throttle 360, the control piston 302 moves backward. The brake fluid in the rear wheel cylinder 28 is almost returned to the master cylinder 12 by the time when the valve element 334 is advanced at a slower speed and the valve element 334 is seated on the valve seat 346. On-off valve for bypass 3
Even if the brake fluid remains in the rear wheel cylinder 28 when the valve 32 is closed, the brake fluid remains in the valve seat 346.
Through the groove 348 formed in the master cylinder pressure chamber 31
4 and can be returned to the master cylinder 12, and dragging does not occur due to the residual pressure in the rear wheel cylinder 28.

When the depressing force of the brake pedal 10 is excessive with respect to the friction coefficient of the road surface and the antilock control is performed, the eccentric cam 98 is rotated and the pressure increasing electromagnetic on-off valve 64 is closed, while the pressure reducing pressure is reduced. The electromagnetic opening / closing valve 70 is opened, the brake fluid in the rear wheel cylinder 28 flows out to the rapid pressure reducing reservoir 74, and the wheel cylinder pressure is reduced. The bypass on-off valve 332 is open, but the pressure-increasing electromagnetic on-off valve 64 is closed.
When the pressure is reduced, the brake fluid is not supplied to the rear wheel cylinder 28 and the reduction of the wheel cylinder pressure is not hindered. The brake fluid that has flown into the rapid decompression reservoir 74 is pumped up by the decompression pump device 106 and returned to the master cylinder 12.

If the depression of the brake pedal 10 is released during the pressure increase of the antilock control, the brake fluid in the rear wheel cylinder 28 passes through the pressure increasing electromagnetic on-off valve 64, the bypass on-off valve 332, and the master cylinder pressure chamber 314. Return to the master cylinder 12. At the end of the anti-lock control by releasing the depression of the brake pedal 10, after the bypass opening / closing valve 332 is closed, the brake fluid in the rear wheel cylinder 28 returns to the master cylinder 12 through the groove 348, which is the same as in normal braking. Is.

During the acceleration slip control, the eccentric cam 98 is rotated, the pressure increasing electromagnetic on-off valve 64 is opened and the pressure reducing electromagnetic on-off valve 70 is closed, and the brake fluid is supplied to the rear wheel cylinder 28. Since the pressure-increasing electromagnetic on-off valve 64 is opened, the brake fluid in the rear wheel cylinder 28 slightly leaks to the master cylinder 12 side through the groove 348 of the bypass on-off valve 332, but the brake fluid increases by that amount. The pressure is replenished by the pressure pump device 76, the hydraulic pressure does not become insufficient, the rotation of the left rear wheel 26 is suppressed, and the slip is reduced. Since the wheel cylinder pressure is reduced and maintained during the acceleration slip control in the same manner as in the embodiment shown in FIGS. 1 and 2, the description thereof will be omitted.

In the embodiment shown in FIGS. 5 and 6, liquid may be used instead of air to allow the movement of the control piston. For example, in the opening / closing control device 370 of the pilot-type closing delay valve 368 shown in FIG. 7, the speed control chamber 376 is formed by fitting the control piston 374 to the control housing 372, and the control piston 37 is formed.
A variable volume chamber 378 is formed in the inner space 4. A liquid is enclosed in the speed control chamber 376 and the variable volume chamber 378, but a rubber gas bag 380 is arranged in the variable volume chamber 378, and the gas bag 380 is compressed and expanded to expand. The volume of the variable volume chamber 378 is variable.

Speed control chamber 376 and variable volume chamber 378
Are connected by a first liquid passage 382 and a second liquid passage 384 that are parallel to each other. A throttle 386 is provided in the first liquid passage 382.
The second liquid passage 384 is provided with a check valve 388 which allows the flow of the liquid from the speed control chamber 376 to the variable volume chamber 378 but prevents the flow in the reverse direction. In the opening / closing control device 370, when the control piston 374 is retracted, the liquid in the speed control chamber 376 flows into the variable volume chamber 378 while compressing the gas bag 380 from both the check valve 388 side and the throttle 386 side. Is allowed by
The liquid in the variable volume chamber 378 is permitted by flowing out to the speed control chamber 376 through the throttle 386, and the control piston 374 advances at a slower speed than when it retracts.

Although the bypass opening / closing valves 138 and 332 are provided in the above embodiments so that the brake fluid in the rear wheel cylinder 28 is returned to the master cylinder 12, the bypass opening / closing valve is provided. Is not essential and may be omitted as shown in FIG. In this case, for example, during normal braking, the brake pedal 1
It is detected that the depression of 0 is released based on the detection signal of the brake switch 62, the solenoid valve 64 for pressure increase is closed, the solenoid valve 70 for pressure reduction is opened, and the pump device 106 for pressure reduction is operated, so that the rear wheel The brake fluid in the cylinder 28 is caused to flow out to the sudden pressure reducing reservoir 74, and is pumped up from the sudden pressure reducing reservoir 74 and returned to the master cylinder 12. The same is true at the end of the antilock control and the acceleration slip control.

A pedaling force sensor 400 for detecting the pedaling force of the brake pedal 10 and a wheel cylinder pressure sensor 402 for detecting the hydraulic pressure of the rear wheel cylinder 28 are provided to output a detection signal to the antilock control unit.
When the depression of the brake pedal 10 is released during normal braking or pressure increase in antilock control, the pressure increasing electromagnetic on-off valve 64 and the pressure reducing electromagnetic on-off valve 70 are opened to allow the brake fluid to flow out from the rear wheel cylinder 28. . When the wheel cylinder pressure reaches a height corresponding to the stepping force of the brake pedal 10, by opening the pressure increasing electromagnetic opening / closing valve 64 and closing the pressure reducing electromagnetic opening / closing valve 70,
It is possible to obtain a wheel cylinder pressure having a height corresponding to the depression force of the brake pedal 10.

It is not essential to share a part of the pressure increasing piston driving device and the pressure reducing piston driving device, and they may be provided independently. In this way, the pressure increasing pump device and the pressure reducing pump device can be operated independently, for example, only the pressure reducing pump device is operated during antilock control and only the pressure increasing pump device during acceleration slip control. Can be activated. An urging means which is a kind of elastic member such as a spring is provided in the rapid decompression reservoir so that the brake fluid discharged to the rapid decompression reservoir is returned from the rapid decompression reservoir to the pressure increasing passage side by the urging means. If so, it is not indispensable to pump and return by the pump device.

Further, it is not essential to keep the wheel cylinder pressure in the antilock control and the acceleration slip control, and the wheel slip may be kept within an appropriate range by increasing and decreasing the pressure. In this case, the bypass passage provided with the relief valve can be omitted.

Further, an electromagnetic opening / closing valve is provided in place of the bypass opening / closing valve and the opening / closing control device so that the brake fluid in the wheel cylinder is returned to the master cylinder when the brake is released or when the depression of the brake pedal is loosened. You may Brake operation member detection means for detecting operation of a brake operation member such as a brake pedal, wheel cylinder pressure detection means for detecting wheel cylinder pressure, and operation force detection means for detecting operation force of the brake operation member are provided. When the operation is released or when the acceleration slip control ends, the solenoid on-off valve is opened to return the brake fluid in the wheel cylinder to the master cylinder, and when the operation of the brake operation member is loosened, the height corresponding to the operation force is adjusted. The solenoid valve is opened until the wheel cylinder pressure is obtained.

Furthermore, the present invention can be applied to a brake fluid pressure control device for a front-wheel drive vehicle or a four-wheel drive vehicle, and the left front wheel and the right rear wheel, and the right front wheel and the left rear wheel are the master cylinders, respectively. It can also be applied to a brake hydraulic pressure control device of an X-pipe type hydraulic brake device connected to one pressurizing chamber. Further, the present invention can be implemented in a mode in which the combination of the constituent elements of each of the above-described embodiments is changed. Besides, the present invention can be implemented 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 showing a hydraulic brake device including a brake hydraulic pressure control device that is an embodiment common to the first and second inventions.

FIG. 2 is a front cross-sectional view showing a bypass on-off valve and an on-off control device which constitute a pilot-type blockage delay valve of the brake fluid pressure control device.

FIG. 3 is a system diagram showing a hydraulic brake device including a brake hydraulic pressure control device that is another embodiment common to the first and second inventions.

FIG. 4 is a system diagram showing a hydraulic brake device equipped with a brake hydraulic pressure control device that is another embodiment common to the first and second inventions.

FIG. 5 is a system diagram showing a hydraulic brake device equipped with a brake hydraulic pressure control device which is another embodiment common to the first and second inventions.

6 is a front cross-sectional view showing a bypass on-off valve and an on-off control device which constitute a pilot-type blockage delay valve of the brake fluid pressure control device shown in FIG.

FIG. 7 is a front cross-sectional view showing another mode of a bypass on-off valve and an on-off control device which constitute a pilot-type blockade delay valve.

FIG. 8 is a system diagram showing a hydraulic brake device including a brake hydraulic pressure control device which is another embodiment common to the first and second inventions.

[Explanation of symbols]

 12 Master Cylinder 18 Left Front Wheel 20 Front Wheel Cylinder 24 Liquid Passage (Pressure Increase Passage) 26 Left Rear Wheel 28 Rear Wheel Cylinder 60 Antilock Control Unit 64 Pressure Increase Electromagnetic Open / Close Valve 68 Liquid Passage (Depressurization Passage) 74 Rapid Pressure Reduction Reservoir 76 Booster pump device 80 Booster piston 82 Booster pump chamber 84 Suction valve 86 Discharge valve 90 Booster control pressure chamber 94 Drive piston 98 Eccentric cam 102 Drive piston drive device 104 Booster piston drive device 106 Pressure reducing pump device 110 For depressurizing Piston 114 Pressure reducing pump chamber 116 Suction valve 118 Discharge valve 122 Pressure reducing control pressure chamber 124 Pressure reducing piston driving device 138 Bypass opening / closing valve 140 Opening / closing control device 142 Pilot type closing delay valve 152 Control piston 154 Master cylinder pressure chamber 1 72 Speed control chamber 178 Check valve 182 Connection passage 184 Throttling 188 Spring 202 Acceleration slip control unit 206 Pressure boosting pump device 208 Pressure boosting piston drive device 210 Pressure reducing pump device 212 Pressure reducing piston drive device 214 Eccentric cam 216 Pressure boosting piston 218 Pressure reducing piston 222 Pressure increasing pump chamber 232 Pressure reducing pump chamber 240 Left rear wheel 242 Right rear wheel 244 Pressure increasing passage 246 Pressure reducing passage 248 Pressure increasing pump device 250 Pressure reducing pump device 252 Rapid pressure reducing reservoir 254 Pilot-type delay valve 266 , 268 Rear wheel cylinders 270, 272 Pressure increasing solenoid valve 280, 282 Pressure reducing solenoid valve 298 Pilot type closing delay valve 300 Closing control device 302 Control piston 314 Master cylinder pressure chamber 320 speed Degree control chamber 332 bypass opening / closing valve 354 gas chamber 360 throttle 362 check valve 368 pilot closing delay valve 370 opening / closing control device 374 control piston 376 speed control chamber 378 variable volume chamber 386 throttle 388 check valve

Claims (2)

[Claims] 1. A master cylinder, a brake including a wheel cylinder for suppressing wheel rotation, a pressure increasing passage connecting the master cylinder and the wheel cylinder, and a pressure increasing passage provided in parallel with the pressure increasing passage. A pressure reducing passage connecting the master cylinder and the wheel cylinder, and an antilock control pressure increasing unit which is provided in the pressure increasing passage and allows the flow of the brake fluid from the master cylinder to the wheel cylinder during antilock control. The anti-lock control decompression unit provided in the decompression passage and temporarily returning the brake fluid in the wheel cylinder to the rapid decompression reservoir during anti-lock control and returning to the master cylinder side, and a hydraulic pressure source Is provided in the pressure-increasing passage, and the fluid pressure source from the hydraulic pressure source to the wheel cylinder is controlled during acceleration slip control. An acceleration slip control pressure-increasing unit that allows a flow of brake fluid; and a hydraulic pressure source that is provided in the pressure-reducing passage and once flows out the brake fluid in the wheel cylinder to a sudden pressure-reducing reservoir during acceleration slip control. A pressure reducing unit for acceleration slip control returning to the side, an antilock control means for controlling the pressure increasing unit for antilock control and the pressure reducing unit for antilock control during braking to control the slip of the wheels within an appropriate range, and A brake fluid pressure control device comprising: an acceleration slip control means for controlling a pressure increase unit for acceleration slip control and a pressure reduction unit for acceleration slip control to control a slip of a wheel within an appropriate range. 2. The anti-lock control pressure-increasing unit includes a pressure-increasing on-off valve which is provided in the pressure-increasing passage and allows and blocks communication between the master cylinder and the wheel cylinder. A decompression unit, the rapid decompression reservoir connected to the decompression passage, and a decompression on-off valve provided in the decompression passage for allowing and blocking communication between the rapid decompression reservoir and the wheel cylinder; A decompression piston slidably fitted in the housing is provided, and a decompression pump chamber formed by the decompression housing and the decompression piston is connected to the decompression passage and a decompression pump in the decompression passage. It is provided on the side of the rapid decompression reservoir side from the part where the chamber is connected, and allows the flow of brake fluid from the rapid decompression reservoir side to the decompression pump chamber side. But the reverse flow and suction valve for preventing,
It is provided on the master cylinder side from the part of the decompression passage where the decompression pump chamber is connected, and allows a flow of brake fluid from the decompression pump chamber side to the master cylinder side, but prevents it from flowing in the opposite direction. A pressure reducing pump device having a pressure reducing piston driving device that reciprocates the pressure reducing piston, wherein the acceleration slip control pressure increasing unit is slidable in the pressure increasing on-off valve and the pressure increasing housing. And a pressure boosting pump chamber formed by the pressure boosting housing and the pressure boosting piston are connected to the pressure boosting passage, and the pressure boosting pump chamber of the pressure boosting passage is connected to the pressure boosting pump chamber. The intake valve is provided on the master cylinder side from the open part to allow the brake flow from the master cylinder side to the booster pump chamber side, but to prevent the flow in the reverse direction. A discharge valve that is provided on the wheel cylinder side of the passage where the pressure boosting pump chamber is connected and allows the flow of brake fluid from the pressure boosting pump chamber side to the wheel cylinder side, but prevents the flow in the opposite direction. A pressure boosting pump device having a pressure boosting piston drive device that reciprocates the piston, the acceleration slip control depressurizing unit includes the depressurizing on-off valve, and the rapid depressurizing reservoir, and The anti-lock control means controls the pressure increasing on-off valve, the pressure reducing on-off valve and the pressure reducing pump device to perform anti-lock control, and the acceleration slip control means controls the pressure increasing on-off valve, The brake fluid pressure control according to claim 1, wherein the pressure reducing on-off valve and the pressure increasing pump device are controlled to perform acceleration slip control. Location.