JPH0611274Y2 - Hydraulic brake device - Google Patents

Description

The present invention relates to a hydraulic brake device, and in particular,
The present invention relates to a hydraulic brake device that performs braking by using the power pressure of a hydraulic booster.

2. Description of the Related Art Such hydraulic brake devices are already known. The hydraulic brake device described in Japanese Patent Application Laid-Open No. 62-155167 is an example, and this device has (a) two pressurizing chambers, and these pressurizing chambers are operated based on the operation of the brake operating member. A master cylinder for independently generating hydraulic pressure, and (b) a power pressure chamber and a control valve for controlling the power pressure of the power pressure chamber to a height corresponding to the operating force of the brake operating member, A hydraulic booster that operates by power pressure to assist the generation of hydraulic pressure in the pressurizing chamber of the master cylinder; and (c) hydraulic pressure generated in each of the two pressurizing chambers of the master cylinder of the wheel. The first piping system and the second piping system, which are supplied to the wheel cylinder of each brake that suppresses rotation, and (d) the wheel cylinder of the first piping system, with or without passing through the pressurizing chamber of the first piping system. Power to communicate with the power pressure chamber A switching valve that can switch between a pressure chamber communication state and a power pressure chamber cutoff state that communicates with a pressure chamber that supplies hydraulic pressure to the wheel cylinder and does not communicate with the power pressure chamber, and (e) the switching valve To
It is configured to include a switching device that switches to a power pressure communication state when the power pressure rises according to the operating force of the brake operating member and switches to the power pressure chamber cutoff state when the power pressure does not rise according to the operating force. The power pressure chamber may be communicated with the wheel cylinder of the first piping system without passing through the pressure chamber. Japanese Patent Application No. 62-2635 filed by the present applicant
The hydraulic brake device described in the specification of No. 46 is one example.

During normal braking in such a hydraulic brake device, the rotation of the wheels of the first piping system is suppressed by the power pressure, and the rotation of the wheels of the other piping system is the hydraulic pressure generated in the pressurizing chamber of the master cylinder. (Hereinafter referred to as master cylinder hydraulic pressure). If the power pressure cannot be obtained due to a failure of the hydraulic pressure source of the hydraulic booster,
The switching valve is switched to a state in which the wheel cylinder communicates with the pressurizing chamber but does not communicate with the power pressure chamber, and the master cylinder hydraulic pressure is supplied to the wheel cylinder to secure the braking force. Further, even if an abnormality such as a liquid leak occurs in the first piping system, the supply of power pressure to the wheel cylinders is cut off, so that the reduction in power pressure is prevented.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, although the power pressure is normally obtained such as liquid leakage in the piping system, the rotation of the wheels of the two piping systems is suppressed based on the master cylinder hydraulic pressure. In this case, there is a problem that the operation amount of the brake operating member is increased and the operability is reduced as compared with the case where only the rotation of the wheels of one piping system is suppressed based on the master cylinder hydraulic pressure. When the power pressure is supplied to the wheel cylinder, the hydraulic pressure is generated in the pressurizing chamber that supplies the hydraulic pressure to the wheel cylinder, but the volume hardly changes, and the operation amount of the brake operating member is one. The amount of brake fluid to be supplied by reducing the volume of the pressure chamber is sufficient, and the amount is small, whereas in the case of fluid leakage, the amount of operation to supply brake fluid from the pressure chamber of the normal system. In addition to this, the operation amount increases as the volume of the pressurizing chamber of the system where the liquid leaks decreases. When the wheel cylinder is disconnected from the power pressure chamber due to an abnormality other than liquid leakage, the pressure applied to the power pressure chamber does not have to decrease to the minimum volume of the pressure chamber as in the case of liquid leakage, A volume change is required to supply the brake fluid from the chamber to the wheel cylinder, which increases the operation amount.

The present invention provides a two-system hydraulic brake device capable of suppressing an increase in the operation amount of a brake operating member when the first piping system to which brake fluid is supplied from the power pressure chamber fails due to liquid leakage or the like. It was made as an issue to provide.

Means for Solving the Problems In order to solve the above-mentioned problems, a hydraulic brake device according to the present invention comprises: (a) a master cylinder; (b) a hydraulic booster;
(c) First and second piping systems, (d) switching valve (this switching valve is referred to as the first switching valve), and (e) in a hydraulic brake device equipped with a switching device, a wheel cylinder of the second piping system. And a pressurizing chamber that supplies hydraulic pressure to the wheel cylinder,
A second switching valve is provided between the hydraulic pressure booster and the power pressure chamber so that the wheel cylinder can communicate with the pressure chamber and the power pressure chamber can communicate with the power pressure chamber. Along with the provision, the switching device, the failure detection means for detecting the failure of the first piping system and issuing a failure detection signal, and the second switching valve is always kept in communication with the pressurizing chamber,
A failure-time switching means for switching the second switching valve to the power pressure chamber communication state and switching the first switching valve to the power pressure chamber shutoff state in response to the failure detection signal is provided.

Functions and Effects In the hydraulic brake device configured as described above,
When the first piping system is damaged due to liquid leakage or the like, the power pressure chamber is connected to the second piping system instead of being shut off from the first piping system. Therefore, the volume of the pressurizing chamber that supplies hydraulic pressure to the wheel cylinders of the second piping system is reduced as compared with the case where the power pressure chamber is simply shut off from the first piping system when the first piping system fails. Therefore, the operation amount for the brake operation member is not required, the operation amount of the brake operation member is small, and the operability is improved.

Further, since the power pressure chamber is disconnected from the failed first piping system, it is possible to prevent the brake fluid in the power pressure chamber from continuing to flow out from the failed first piping system, resulting in a shortage of the brake fluid. .

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

In the attached drawings, 10 is a master cylinder, and 12 is a hydraulic booster. Although the master cylinder 10 and the hydraulic booster 12 are shown as sharing a single housing 14, the housing 14 is actually formed by integrally fixing a plurality of members. A first pressurizing piston 18 and a second pressurizing piston 20 are fitted in a liquid-tight and slidable manner in a cylinder bore 16 formed in the housing 14, respectively, and the first pressurizing piston 18 and the second pressurizing piston 20 are respectively mounted on the front sides of the pistons 18 and 20 in the front side. A pressure chamber 22 and a second pressure chamber 24 are formed. The hydraulic pressure generated in the first pressurizing chamber 22 is supplied to the front wheel cylinders 34, 36 of the brakes of the left front wheel 30 and the right front wheel 32 through the port 26 and the liquid passage 28, and is generated in the second pressurizing chamber 24. Hydraulic pressure applied to port 3
8, the liquid passage 40 supplies the left rear wheel 42 and the right rear wheel 44 to the rear wheel cylinders 46 and 48 of the brake. This hydraulic brake system is a front and rear two-system type. The left and right front wheels 30, 32 and the left and right rear wheels 42, 44 are respectively
Antiskid actuators 50 and 52 are used for antiskid control. Although not shown, these actuators 50 and 52 are provided with electromagnetic control valves that can be switched to three positions, and the slip rate of the wheels is kept within an appropriate range by increasing, holding, and reducing the hydraulic pressure of the wheel cylinders. It is like this. This switching is performed by the control device 56 while detecting the slip ratio of the wheels, but since it is a well-known control, detailed description will be omitted. An ignition switch 58 is connected to the control device 56 so that the operation is started when the engine is started.

An annular groove 64 is formed on the outer peripheral surface of the first pressurizing piston 18, and the annular groove 64 is always communicated with the reservoir 70 via the port 66 and the liquid passage 68. Reservoir 7
At 0, a level warning switch 71 that detects a decrease in the liquid amount and generates a signal is provided, and the detection signal is supplied to the control device 56. A cup seal 72 is attached to the first pressurizing piston 18,
The flow of the brake fluid from the annular groove 64 to the first pressurizing chamber 22 is allowed, but the reverse flow is blocked. The first pressurizing piston 18 is further formed with a communication passage 74 that communicates the annular groove 64 with the first pressurizing chamber 22, and a valve 76, a valve seat 78 and a spring 80 are provided in the communication passage 74. Is provided with a check valve 82.
A rod 84 extends forward from the valve 76, penetrates the bottom of a bottomed cylindrical valve opening member 86, and engages with the bottom at a head 88. A return spring 88 is provided between the valve opening member 86 and the first pressurizing piston 18, presses the valve opening member 86 against the bottom of the cylinder bore 16, and contacts the first pressurizing piston 18 with a stopper bolt (not shown). In this state, the valve 76 is slightly separated from the valve seat 78 by the valve opening member 86 via the rod 84, and the check valve 82 is forcibly opened.

An annular groove 94 is also formed on the outer peripheral surface of the second pressurizing piston 20 by the action of the port 96 and the liquid passage 98.
It is always connected to 0. Also, the cup seal 10
0 is mounted, and a check valve 110 including a communication passage 102, a valve element 104, a valve seat 106, and a spring 108.
Is provided, and the rod 112 extended from the valve element 104 is engaged with the first pressurizing piston 18. The second pressurizing piston 20 is biased to the retracted end position by the return spring 114 provided between the second pressurizing piston 20 and the first pressurizing piston 18, and the check valve 110 is opened.

A space that opens into the cylinder bore 16 is also formed in the housing 14, and the power piston 124 is concentric with the second pressurizing piston 20 and is fitted in a liquid-tight and slidable manner. Is divided into a low pressure chamber 126 communicating with the annular groove 94 and a power pressure chamber 128 on the front side of the power piston 124. A small diameter portion 130 extends from the central portion of the rear surface of the power piston 124, and penetrates the end wall of the housing 14 in a liquid-tight and slidable manner and is exposed to the atmosphere. A bottomed hole 132 is formed in the small-diameter portion 130 from the rear end surface thereof, and a reaction piston 134 is fitted therein in a liquid-tight and slidable manner. As a result, a space is formed between the reaction piston 134 and the bottom surface of the bottomed hole 132, but this space is communicated with the power pressure chamber 128 by the communication passage 136, and the power pressure chamber 128.
A reaction force having a magnitude proportional to the hydraulic pressure is applied to the input rod 138.

The input rod 138 has a reaction piston 134 crimped at its tip, while its rear end is connected to a brake pedal 140, which is a brake operating member.
It is biased in the backward direction by a return spring (not shown). The reaction piston 134 is designed to have a relative movement limit with respect to the power piston 124, and the return spring also functions as the return spring of the power piston 124. The retracted end position of the power piston 124 is defined by the stopper protrusion 142, and the operating force thereof is transmitted to the second pressure piston 20 by the relay rod 144.

The hydraulic booster 12 includes a control valve 150. The control valve 150 includes a valve spool 154 fitted in the housing 14 so as to be liquid-tight and slidable. A low pressure port 156 is formed in the housing 14 and a liquid passage 158 is formed.
Is connected to the reservoir 70, a high pressure port 160 is formed behind the low pressure port 156 (right side in the drawing), and is connected to the accumulator 164 by a liquid passage 162. The brake fluid in the reservoir 70 is supplied to the accumulator 164 by the pump 165, and the hydraulic pressure in the accumulator 164 is determined by the pressure sensor 1.
The start / stop of the motor 168 is controlled by the control device 56 on the basis of the output signal of the control unit 66 so that the motor 168 is kept in a certain range.

The valve spool 154 is biased in the backward direction by the spring 170, and when in the normal position shown in the drawing, the communication hole 172 causes the low pressure port 156 to move to the power pressure chamber 12.
8, and the high pressure port 160 is blocked. By moving the valve spool 154 forward from this position by a certain distance (moving to the left in the figure), both the low pressure port 156 and the high pressure port 160 are blocked, and by further moving forward, the low pressure port 156 is blocked and the high pressure port 156 is blocked. The port 160 is communicated with the power pressure chamber 128.

This movement of the valve spool 154 is caused by the advance of the reaction piston 134 relative to the power piston 124. Reaction piston 134
Is engaged with the other end of a first link 174, one end of which is rotatably supported by the housing 14, while the power piston 124 is rotatably connected to an intermediate part of the first link 174. One end of the second link 176 is engaged. The other end of the second link 176 is engaged with the end surface of the valve spool 154, and when the reaction piston 134 moves forward relative to the power piston 124, the first link 174 moves clockwise in the drawing. While the second link 176 is rotated counterclockwise, the valve spool 15 is rotated.
4 is advanced and the control valve 150 is switched.

The annular groove 64 of the master cylinder 10 has the liquid passage 18
0, the port 182 is connected to the power pressure chamber 128, and the power pressure is supplied to the front wheel cylinders 34, 36 through the liquid passage 180, the annular groove 64, the communication passage 74, the first pressurizing chamber 22, and the liquid passage 28. It is supposed to be done. An electromagnetic opening / closing valve 184 is provided in the liquid passage 180. The solenoid opening / closing valve 184 is closed when the solenoid is demagnetized to close the front wheel cylinders 34, 36 to the first pressurizing chamber 2.
2, but not to the power pressure chamber 128,
When excited, the front wheel cylinders 34 and 36 are opened to communicate with the power pressure chamber 128 via the first pressure chamber 22.
The electromagnetic opening / closing valve 184 constitutes a first switching valve, and the opening / closing of the opening / closing valve 184 is performed by the control device 56. The control device 56 constitutes a switching device.

In addition, the first pressure chamber 22, the second pressure chamber 24 and the left and right front wheels 3
0, 32, liquid passage 2 connecting left and right rear wheels 42, 44
8 and 40 are electromagnetic directional control valves 188 and 190, respectively.
Is provided. These switching valves 188, 190 are connected to the power pressure chamber 128 via the liquid passage 180 and the port 182, and the wheel cylinders 34, 36, 46,
The first state in which 48 communicates with the pressure chambers 22 and 24 is switched to the second state in which the pressure chamber communicates with the power pressure chamber 128. This switching is performed by the control device 56, and the demagnetization of the solenoid brings the switching to the first state, and the excitation causes the switching to the second state. These electromagnetic directional control valves 188 and 190 are provided to switch the hydraulic pressure source during normal braking and anti-skid control. The electromagnetic directional control valve 190 serves as a second directional control valve as will be described later. Also works.

In the hydraulic brake device configured as described above,
When the engine, which is the main body of the control device 56, is initialized when the engine is started, the electromagnetic opening / closing valve 184 is opened, and the front wheel cylinders 34 and 36 are communicated with the power pressure chamber 128. Electromagnetic directional control valve 188,1
The solenoid 90 remains demagnetized, and the wheel cylinders 34, 36, 46 and 48 are in communication with the pressurizing chambers 22 and 24. Therefore, the brake pedal 14
When 0 is depressed, the input rod 138 is moved forward and the valve spool 154 is moved forward, so that the power pressure chamber 128 is blocked from communicating with the low pressure port 156, while being communicated with the high pressure port 160, and brake fluid is discharged. Although it flows in, a part of it is supplied to the front wheel cylinders 34, 36 to operate the front wheel cylinders 34, 36, and the power piston 124 moves forward to move the second pressurizing piston 20 forward. The brake fluid in the second pressurizing chamber 24 is the rear wheel cylinder 4
6,48 to activate it. At this time, a hydraulic pressure having a height corresponding to the stepping force of the brake pedal 140 is generated in the first pressurizing chamber 22, but the power pressure is supplied to the front wheel cylinders 34, 36, so that the first pressurizing chamber 22 receives the first pressurizing force. The pressure piston 18 hardly moves forward, and the stroke of the brake pedal 140 is correspondingly short.

When the slip ratio of the wheel becomes high and the anti-skid control is performed, the electromagnetic directional control valves 188, 190 cause the wheel cylinders 34, 36, 46, 48 to move to the power pressure chamber 12.
8 is switched to a state of being communicated. Since the anti-skid control is performed using the accumulator 164 as a hydraulic pressure source, the brake pedal 140 does not have to be recoiled even if the wheel cylinder hydraulic pressure is increased or decreased. In addition,
If the power pressure cannot be obtained during the anti-skid control, or if an abnormality such as liquid leakage occurs in the front system,
The electromagnetic directional control valves 188 and 190 are wheel cylinders 3.
The state in which 4, 36, 46, 48 are communicated with the pressurizing chambers 22, 24 is switched.

When the power pressure cannot be obtained due to a failure of the accumulator 164, the pump 165, etc. during normal braking, the control device 56 closes the electromagnetic on-off valve 184 based on the detection of the pressure sensor 166, and the front wheel cylinders 34, 3 are detected.
6 is communicated only with the first pressure chamber 22 and the power pressure chamber 128
It should not be connected to the. Thereby, the first pressurizing chamber 2
The hydraulic pressure generated in 2 is applied to the front wheel cylinder 3
It is supplied to 4, 36, and the braking force is secured. At this time, even if the electromagnetic on-off valve 184 fails and the communication between the front wheel cylinders 34, 36 and the power pressure chamber 128 cannot be interrupted (the electromagnetic on-off valve 184 is a normally closed valve, However, the power pressure chamber 128 is connected to the front wheel cylinders 34 and 36 through the first pressurizing chamber 22 and is not connected to the first pressurizing piston 18. Since the cup seal 72 that functions as a stop valve and the check valve 82 are provided, the brake fluid of the front wheel cylinders 34 and 36 does not leak to the power pressure chamber 128 side, and the front wheel cylinders 34 and 36 do not leak. The hydraulic pressure generated in the first pressurizing chamber 22 is supplied to suppress the rotation of the wheels.
Cup seal 72 or check valve 82, solenoid valve 18
4. The braking force cannot be obtained only when all of the hydraulic boosters 12 fail, so it can be said that the braking device has extremely high safety.

Further, when the front system leaks due to liquid leakage, the amount of liquid in the reservoir 70 decreases, and the control device 56 closes the electromagnetic opening / closing valve 184 and switches the electromagnetic direction based on the detection signal of the level warning switch 71. The valve 190 is switched to a state in which the wheel cylinders 46 and 48 are in communication with the power pressure chamber 128. As a result, the power pressure is prevented from flowing out, the master cylinder assisting function of the hydraulic booster 12 is maintained, and the rotation of the rear wheels 42, 44 is suppressed based on the power pressure. Therefore, as the brake pedal 140 is depressed, the first pressurizing piston 1
8 is moved, the pedal stroke for reducing the volume of the second pressurizing chamber 24 is not necessary, and the depression amount of the brake pedal 140 is correspondingly small.

As is clear from the above description, in this embodiment, the piping system connecting the first pressurizing chamber 22 and the front wheel cylinders 34, 36 constitutes the first piping system referred to in the scope of utility model registration claims. A piping system connecting the second pressurizing chamber 24 and the rear wheel cylinders 46, 48 constitutes a second piping system. Further, the electromagnetic opening / closing valve 184 constitutes the first switching valve, and the electromagnetic directional switching valve 190 constitutes the second switching valve, respectively, and the control device 56 and the level warning switch 7 are provided.
Reference numeral 1 constitutes a switching device for these switching valves. Then, the level warning switch 71 constitutes a failure detection means, and a part of the control device 56, that is, an electromagnetic opening / closing valve 184 in response to a liquid amount decrease detection signal from the level warning switch 71 (this is a failure detection signal). Closed to close the power pressure chamber 128 to the front wheel cylinder 3
A portion for switching the electromagnetic directional control valve 190 to a state in which the rear wheel cylinders 46, 48 and the power pressure chamber 128 communicate with each other while shutting off from the valves 4, 36 constitutes a failure switching means.

As described above, in this hydraulic brake device, the electromagnetic directional control valve 19 provided for performing the anti-skid control is provided.
0 is made to function as the second switching valve, and a hydraulic brake device having a short stroke of the brake pedal 140 can be obtained by only adding the electromagnetic opening / closing valve 184 and slightly changing the control of the control device 56. Can be suppressed. However, it is also possible to apply the present invention to a hydraulic brake device that does not have an anti-skid device.

Further, in the above-described embodiment, the power pressure supply is switched from the front system to the rear system due to liquid leakage, but an abnormality occurs in the front system that requires cutting off the power pressure supply in addition to liquid leakage. In this case, the electromagnetic on-off valve 184 and the electromagnetic directional control valve 190 may be switched based on the detection of the abnormality.

Furthermore, in the above-described embodiment, the power pressure is supplied to the front wheel cylinders 34 and 36 through the first pressurizing chamber 24, but the power pressure is supplied without passing through the first pressurizing chamber 24. The present invention can also be applied to a hydraulic brake device that is used.

Further, in the above-described embodiment, the rotation of the wheels of the front system is suppressed based on the power pressure and the rotation of the wheels of the rear system is converted to the master cylinder hydraulic pressure during normal braking in the hydraulic brake device of the front and rear two systems type. However, the present invention can be applied to not only the front and rear two-system type but also the cross piping type hydraulic brake device.

In addition, although not exemplified, the present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

The attached drawing is a system diagram of a hydraulic brake device according to an embodiment of the present invention. 10: Master cylinder, 12: Hydraulic booster 22: First pressurizing chamber, 24: Second pressurizing chamber 28: Liquid passage, 30: Left front wheel 32: Right front wheel 34, 36: Front wheel cylinder 42: Left rear wheel , 44: right rear wheel 46, 48: rear wheel cylinder 56: control device, 64: annular groove 74: communication passage, 128: power pressure chamber 140: brake pedal, 180: liquid passage 184: solenoid on-off valve, 190: electromagnetic Direction switching valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Rinji Nishii 2-1-1 Asahi-cho, Kariya city, Aichi Prefecture Aisin Seiki Co., Ltd. (56) References JP-A-57-90249 (JP, A)

Claims (1)

[Scope of utility model registration request] 1. A master cylinder having two pressurizing chambers for independently generating hydraulic pressure in the pressurizing chambers based on an operation of a brake operating member, a power pressure chamber and a power pressure of the power pressure chamber. And a control valve for controlling the height to correspond to the operating force of the brake operating member, and a hydraulic booster that operates at the power pressure to assist the generation of hydraulic pressure in the pressurizing chamber of the master cylinder, A first piping system and a second piping system for supplying hydraulic pressures respectively generated in the two pressurizing chambers of the master cylinder to respective wheel cylinders of a brake for suppressing rotation of a plurality of wheels; System wheel cylinder is communicated with the power pressure chamber communicating with the power pressure chamber via the pressure chamber of the first piping system, and with the pressure chamber supplying hydraulic pressure to the wheel cylinder. And a state in which the power pressure rises according to the operating force of the brake operating member, and a first switching valve that can switch to a power pressure chamber shut-off state in which the power pressure chamber is not communicated A hydraulic brake device including a switching device that is in the power pressure communication state and that switches to the power pressure chamber cutoff state when the power cylinder does not rise in response to an operating force. Between the pressure chamber that supplies hydraulic pressure to the power pressure chamber and the power pressure chamber, there are a pressure chamber communication state in which the wheel cylinder communicates with the pressure chamber and a power pressure chamber communication state in which the wheel cylinder communicates with the power pressure chamber. Provided with a switchable second switching valve,
In the switching device, a failure detection unit that detects a failure of the first piping system and issues a failure detection signal, and always keep the second switching valve in the communication state with the pressurizing chamber, The hydraulic pressure is provided with a failure-time switching means for switching the second switching valve to the power pressure chamber communication state in response to the failure detection signal and for switching the first switching valve to the power pressure chamber cutoff state. Brake device.