JPH06305410A - Brake - Google Patents

Abstract

PURPOSE:To restrain lower durability of an electromagnetic liquid pressure control valve and the deterioration of brake structural members when a vehicle is kept in a braked condition by liquid pressure in wheel cylinders, after stopped. CONSTITUTION:Either liquid pressure in a master cylinder or electric control liquid pressure in a spool electromagnetic liquid pressure control valve 160, whichever higher. is selected by change valves 210, 212 and supplied to wheel cylinders 34, 36, 42, 44. If the danger of collision with an obstruction is detected by a radar 280, a liquid pressure controller 274 supplies a large current to the electromagnetic liquid pressure control valve 160 to cause the maximum liquid pressure to be supplied to the wheel cylinders 34, 36, 42, 44 by opening an electromagnetic switch valve 270. After stopped, the supplied current is reduced to a quantity enough to stop an automobile on a road surface of 30% gradient, so that the deterioration of a permanent magnet due to heat of an exciting coil and the deterioration of brake structural members including a rubber hose and seal material due to supply of high liquid pressure to a brake cylinder are restrained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake system, and more particularly to control of wheel cylinder hydraulic pressure after a vehicle is stopped.

[0002]

2. Description of the Related Art Some brake devices are configured to electrically control the hydraulic pressure of a wheel cylinder.
This type of brake device generally includes a wheel cylinder of a brake that brakes a vehicle, a hydraulic pressure control device that electrically controls the hydraulic pressure of the wheel cylinder, and a hydraulic pressure control device control that controls the hydraulic pressure control device. And means.

The brake device described in Japanese Patent Laid-Open No. 4-218458 is an example. In this brake device, the hydraulic pressure control device controls the hydraulic pressure of the accumulator to a height according to the operation amount of the brake operating member by the spool type electromagnetic hydraulic pressure control valve and supplies it to the wheel cylinder. The control device control means controls the amount of current supplied to the spool-type electromagnetic hydraulic pressure control valve.

Further, for example, as in a brake device equipped with a return type anti-lock device, the hydraulic pressure supplied from the master cylinder to the wheel cylinder when the driver depresses the brake pedal becomes excessive by switching the solenoid valve. There is also a braking device that controls the height to eliminate slip.
In any case, in the brake device in which the hydraulic pressure of the wheel cylinder is electrically controlled, the hydraulic pressure control device control means controls the hydraulic pressure control device to control the hydraulic pressure of the wheel cylinder by the driver's brake operation. The height can be controlled based on the operation amount of the member, or can be controlled to a height that is independent of the operation amount.

[0005]

However, in a vehicle, even after the vehicle is stopped, hydraulic pressure may be supplied to the wheel cylinders to keep the wheels from rotating. In that case, as described above, Various problems occur in a brake device in which the hydraulic pressure of a cylinder is electrically controlled. For example, an obstacle detection device for detecting an obstacle is added to the brake device described in the above publication so that current is supplied to the spool-type electromagnetic hydraulic control valve when there is a risk of collision with the obstacle. Then, the rotation of the wheels can be automatically suppressed even if the driver does not operate the brake. However, it is not preferable to maintain the state in which a high hydraulic pressure is generated in the wheel cylinders even after the vehicle is stopped by performing the emergency braking for avoiding the collision with the obstacle in this way. If high hydraulic pressure continues to be supplied to the wheel cylinders, a high load will be applied to the brake components,
This is because the brake components such as the rubber hose and the seal member may be deteriorated faster.

This problem is not limited to the case where the spool-type electromagnetic hydraulic pressure control valve controls the hydraulic pressure supplied to the wheel cylinder, but the hydraulic pressure generated in the master cylinder by the driver's operation of the brake operating member is not limited to the wheel hydraulic pressure control valve. The same happens when the vehicle is kept stationary by supplying it to the cylinders. An object of the present invention is to reduce the load applied to the brake constituent members by setting the hydraulic pressure of the wheel cylinders to a hydraulic pressure necessary for maintaining the stopped state of the vehicle after the vehicle is stopped. .

[0007]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a brake device, a wheel cylinder of a brake for braking a vehicle, and a hydraulic pressure for electrically controlling the hydraulic pressure of the wheel cylinder. When the hydraulic pressure of the control means and the wheel cylinder required to stop the vehicle is equal to or higher than a predetermined value, by controlling the hydraulic pressure control means after stopping the vehicle,
The gist of the present invention is to include a means for controlling hydraulic pressure after the vehicle is stopped, which makes the wheel cylinder hydraulic pressure below the predetermined value.

In this case, the "hydraulic pressure control means" is
A brake device in which the hydraulic pressure of the wheel cylinder is electrically controlled, such as a brake device provided with the spool-type electromagnetic hydraulic pressure control valve described in the above publication or a brake device in which anti-skid control is performed by switching an electromagnetic switching valve. In the above, a spool type electromagnetic hydraulic pressure control valve or an electromagnetic switching valve used for such ordinary braking and anti-skid control can be used. Further, in the brake device in which normal braking is performed by the hydraulic pressure generated in the master cylinder by the driver's operation of the brake operating member,
A hydraulic pressure control device for electrically controlling the hydraulic pressure of the wheel cylinder in order to keep the hydraulic pressure of the wheel cylinder below a predetermined value after the vehicle stops can be provided, and this can be referred to as the "hydraulic pressure control means".

"To set the wheel cylinder hydraulic pressure to a predetermined value or less" includes the case where the predetermined value itself is used and the case where the hydraulic pressure is set lower than the predetermined value. In the latter case, for example, the maximum hydraulic pressure that is higher than the hydraulic pressure of the wheel cylinders that is suitable for keeping the vehicle stationary, and that can be allowed to keep the vehicle stationary considering the load applied to the brake components. If the hydraulic pressure of the wheel cylinder required to stop the vehicle is set to a predetermined value and is slightly higher than the hydraulic pressure of the wheel cylinder suitable for keeping the vehicle in a stopped state, the hydraulic pressure is not reduced. The hydraulic pressure of the wheel cylinder is lower than the specified value,
The hydraulic pressure is reduced to an appropriate level to keep the vehicle stationary. In any case, the height at which the wheel cylinder hydraulic pressure is controlled after the vehicle is stopped is the height required to keep the vehicle in a stopped state, and is not limited to a certain height, and for example, the slope of the road surface or the loading of the vehicle. It is possible to set a plurality of heights according to the magnitude of the load and the like.

[0010]

With this configuration, even if the hydraulic pressure of the wheel cylinder required to stop the vehicle is equal to or higher than a predetermined value, the hydraulic pressure of the wheel cylinder is reduced to or lower than the predetermined value after the vehicle is stopped, and the vehicle has a low wheel cylinder. It is stopped by hydraulic pressure.

[0011]

Therefore, it is possible to avoid a high load being applied to the brake component due to the high hydraulic pressure of the wheel cylinder when the vehicle is stopped, and it is possible to delay the deterioration of the brake component.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an anti-skid / acceleration slip control type hydraulic brake device for a four-wheeled vehicle will be described in detail with reference to the drawings.

In FIG. 1, 10 is a hydraulic booster (hereinafter,
12 is a tandem brake master cylinder (hereinafter simply referred to as a master cylinder).
Is. The master cylinder 12 includes a housing 14 as shown in FIG. A cylinder bore 16 is formed in the housing 14, and a first pressure piston 18 and a second pressure piston 20 are fitted in the cylinder bore 16 in a liquid-tight and slidable manner. As a result, the first pressurizing chamber 22 and the second pressurizing chamber 2 are provided in front of the pistons 18 and 20 (to the left in the figure).
4 is formed, and when the brake pedal 26 is depressed, hydraulic pressure is generated.

As shown in FIG. 1, the first pressurizing chamber 22 has a proportioning bypass valve 28 formed by a liquid passage 27.
The second pressurizing chamber 24 is connected to the rear wheel cylinders 34 and 36 of the respective brakes of the left and right rear wheels 30 and 32 via the proportion passage bypass valve 28 and the pressure booster 37 by the liquid passage 39. Is connected to the front wheel cylinders 42 and 44 of each brake. This hydraulic brake system is a front and rear two-system type.
Further, in this automobile, the left and right rear wheels 30, 32 are driving wheels.

Proportioning bypass valve 28
When the normal hydraulic pressure is generated in both the front wheel system and the rear wheel system, the hydraulic pressure supplied to the rear wheel cylinders 34, 36 is set to the front wheel cylinders 42, 4
When the hydraulic pressure is reduced at a constant ratio with respect to the hydraulic pressure supplied to the front wheel system 4, and the normal hydraulic pressure does not occur in the front wheel system, the hydraulic pressure generated in the first pressurizing chamber 22 is not reduced and the rear wheel It supplies to the cylinders 34 and 36.

The pressure boosting device 37 is a device for boosting the hydraulic pressure in the second pressurizing chamber 24 and supplying it to the front wheel cylinders 42 and 44, the role of which will be described later.

The booster 10 is provided integrally with the master cylinder 12. This booster 10 is disclosed in
This is the same as the booster described in Japanese Patent Publication No. 149547, etc., and will be briefly described. As shown in FIG. 2, a power pressure chamber 62 is formed in the housing 60 of the booster 10, and an input rod 64 is formed when the brake pedal 26 is depressed.
And when the reaction piston 66 is advanced, its forward movement is linked to the first link 68 and the second link 7.
Control valve 74 by a link mechanism 72 composed of 0
Is converted to the forward movement of the spool 76 of the power pressure chamber 62.
Accumulator 80 from the state of communicating with the reservoir 78
It is switched to the state of communicating with. As a result, power pressure is generated in the power pressure chamber 62, the power piston 82 is advanced, the first and second pressure pistons 18, 20 are advanced, and the front and rear wheel cylinders 42,
Hydraulic pressure is transmitted to 44, 34 and 36. The forward movement of the reaction piston 66 is stopped at a position where the pedaling force of the brake pedal 26 and the reaction force are balanced, and the spool 76 is stopped at a position where the power pressure chamber 62 is not communicated with the accumulator 80 or the reservoir 78, and the power pressure chamber 62 is Power pressure is maintained.

The accumulator 80 has a pump 92 in which the brake fluid in the reservoir 78 is driven by a motor 90.
Is supplied via check valve 94. The hydraulic pressure of the accumulator 80 is kept in a constant range by controlling the start / stop of the motor 90 based on the output signal of the pressure sensor 96. Further, the abnormal decrease in the hydraulic pressure of the accumulator 80 is detected by the pressure switch 98,
The brake warning lamp is turned on and the buzzer is activated. The relief valve 100 prevents the hydraulic pressure of the accumulator 80 from becoming abnormally high.

The present hydraulic brake device is adapted to perform antiskid control based on the power pressure generated in the power pressure chamber 62. Therefore, as shown in FIG. 1, two electromagnetic direction switching valves 110 and 112 are provided between the pressure booster 37 and the front wheel cylinders 42 and 44. These electromagnetic direction switching valves 110, 112 are connected to the power pressure chamber 62 by liquid passages 114, 116, 118, respectively, and the liquid passages 114, 116 each have an electromagnetic hydraulic pressure control valve 120 which is a three-way direction switching valve. , 122 are provided. These electromagnetic hydraulic pressure control valves 120, 122
Is connected to the reservoir 78, and the front wheel cylinders 42 and 44 are respectively in communication with the power pressure chamber 62 to increase the hydraulic pressure, and in a reduced pressure state to communicate with the reservoir 78 to decrease the hydraulic pressure. , And it is switched to a holding state in which the hydraulic pressure is held without communicating with either.

An electromagnetic directional control valve 124 is provided in a portion of the liquid passage 27 between the proportioning bypass valve 28 and the rear wheel cylinders 34, 36, and the electromagnetic directional control valve 124 and the rear wheel cylinder 3 are provided.
Electromagnetic hydraulic pressure control valves 126 and 128, which are three-way directional control valves, are provided between the hydraulic pressure control valves 126 and 128. The electromagnetic direction switching valve 124 is connected to the power pressure chamber 62 by the liquid passage 130, and another electromagnetic direction switching valve 13 is provided in the liquid passage 130.
Two are provided. The electromagnetic direction switching valve 132 is the liquid passage 1
The electromagnetic directional control valve 1 is connected to the accumulator 80 by means of 34, and during antiskid control.
Rear wheel cylinder 3 by switching between 24 and 132
4, 36 are connected to the power pressure chamber 62, and the wheel cylinder pressure is increased, decreased, and maintained by the electromagnetic hydraulic pressure control valves 126, 128.

A power pressure is supplied to the pressure booster 37 by a liquid passage 140, and when the booster 10 normally outputs the power pressure, the second pressurizing chamber 24 and the front wheel cylinders 42, 44 are made to communicate with each other. The master cylinder hydraulic pressure is supplied to the front wheel cylinders 42 and 44.
On the other hand, when the booster 10 does not normally generate the power pressure and the power pressure fails, the pressure booster 37 blocks the communication between the second pressure chamber 24 and the front wheel cylinders 42, 44, and the booster piston moves the The hydraulic pressure in the second pressurizing chamber 24 is increased and supplied to the front wheel cylinders 42 and 44.

A differential pressure switch 142 is provided between the liquid pressure supply chamber of the pressure booster 37 and the liquid passage 140, and detects a power pressure failure. ECU
(Electronic control unit) 146 so that anti-skid control is not performed. Further, liquid passage 1
A pressure limiter 144 is provided at 40. When the master cylinder hydraulic pressure is further increased after the power pressure reaches the assist limit, the pressure limiter 144 is provided at the pressure booster 37.
The reverse flow of the brake fluid from the power pressure chamber 62 to the power pressure chamber 62 is prevented so that the pressure increasing action is not performed.

Left and right rear wheels 30, 32 which are driving wheels during acceleration
If the slip of the valve becomes excessive, the electromagnetic directional control valve 1
Rear wheel cylinder 3 by switching between 24 and 132
The hydraulic pressure of the accumulator 80 is supplied to the valves 4, 36, and the wheel cylinder pressure is increased or decreased by switching the electromagnetic hydraulic pressure control valves 126, 128 to eliminate the slip.

The anti-skid control and the acceleration slip control are performed by the ECU 146. ECU14
Reference numeral 6 is mainly composed of a computer, and as shown in FIG. 1, each signal of the pressure sensor 96, the pressure switch 98, and the differential pressure switch 142 and each rotation of the left and right front wheels 38, 40 and rear wheels 30, 32. The detection results of the rotation speed sensors 148, 150, 152, 153 for detecting the speed are supplied, wheel speeds, wheel decelerations, vehicle body speeds, etc. are calculated based on the detection results, and anti-skid control and acceleration slip are performed based on the calculation results. Take control.

A liquid passage 27 connecting the first pressurizing chamber 22 and the proportioning bypass valve 28, a liquid passage 39 connecting the second pressurizing chamber 24 and the proportioning bypass valve 28, and an electromagnetic directional control valve 132. The liquid pressures controlled by the spool-type electromagnetic hydraulic pressure control valve 160 are supplied to the liquid passages 130 connecting to the power pressure chamber 62 by the liquid passages 154, 156 and 158, respectively. The spool-type electromagnetic hydraulic pressure control valve 160 is a valve that controls and supplies the hydraulic pressure of the accumulator 80 to a height proportional to the supply current, and is known from Japanese Utility Model Laid-Open No. 63-40270, and will be briefly described. To do.

The spool type electromagnetic hydraulic pressure control valve 160 is shown in FIG.
As shown in FIG. 1, the valve hole 1 formed in the housing 162
A spool 168 is fitted on the pipe 64 so as to be substantially liquid-tight and slidable. By this movement of the spool 168, the spool-type electromagnetic hydraulic pressure control valve 160 causes the control pressure port 170 connected to the wheel cylinder to be connected to the low pressure port 172 connected to the reservoir 78 via the annular chamber 174 and the annular groove 176. The high pressure port 17 connected to the accumulator 80 and the state in which the wheel cylinder fluid pressure is reduced by communicating with each other.
The wheel cylinder hydraulic pressure is increased by communicating with No. 8 through the annular chamber 174 and the annular groove 180, and the state where the wheel cylinder hydraulic pressure is held without being communicated with any of them is switched.

At one end of the spool 168, the reaction force pin 18
4 is urged by the spring 186 to abut. The reaction force pin 184 receives the hydraulic pressure of the control pressure port 170 supplied from the liquid passage 188 and applies an operating force based on the hydraulic pressure to the spool 168 to cut off the communication between the high pressure port 178 and the control pressure port 170. Generates directional actuation force.

Further, the force 192 applies to the spool 168 a control force in a direction opposite to the above-mentioned operating force, but in a direction for connecting the control pressure port 170 and the high pressure port 178. The force motor 192 is disposed in an air chamber 196 partitioned by a diaphragm 194 provided between the spool 168 and the housing 162, and is provided with a spring 186 when no exciting current is supplied to the exciting coil 198. The force shown in FIG. 3 keeps the spool 168 in the control pressure port 17
0 is connected to the low pressure port 172. When an exciting current is supplied to the exciting coil 198, the exciting coil 198
Are extruded from the yoke 202 by the magnetic field of the permanent magnet 200. As the exciting coil 198 advances, the spool 16
8 is applied with a control force by the reaction force pin 184 in the opposite direction to the operating force, the spool 168 is stopped at a position where the operating force and the braking force are balanced, and the control pressure is the current supplied to the exciting coil 198. The height is controlled according to.

Such a spool type electromagnetic hydraulic pressure control valve 16
Change valves 210, 212, and 214 are provided at the connecting portions of the liquid passages 154, 156, 158 for transmitting the control pressure of 0 and the liquid passages 27, 39, 130, respectively. The hydraulic pressure supplied from the pressure chambers 22 and 24 and the power pressure chamber 62, and the spool-type electromagnetic hydraulic pressure control valve 160
The higher hydraulic pressure of the electric control hydraulic pressures supplied by is selected and supplied to the rear wheel cylinders 34, 36 and the front wheel cylinders 42, 44.

These change valves 210, 212, 2
The configuration of 14 is the same, and the change valve 21
0 will be typically described. As shown in FIG. 4, a through hole 222 penetrating in the longitudinal direction is formed in the housing 220 of the change valve 210, a sleeve 223 is liquid-tightly fitted, and openings at both ends of the through hole 222 are plugs 224, 226. Is closed to form a valve hole 228, and the spool 230 is fitted so as to be movable in the axial direction. A land 23 is provided in the middle of the spool 230 in the longitudinal direction.
2 is formed and fitted into the valve hole 228, so that the master cylinder 12 is connected to the first pressurizing chamber 22 of the master cylinder 12 by the port 234 formed in the plug 224 on one side of the land 232. A pressure chamber 236 is formed, and on the other side of the land 232, a spool type electromagnetic hydraulic pressure control valve 16 is provided by a port 238 formed in the plug 226.
An electrically controlled hydraulic chamber 240 connected to zero is formed. In the change valve 214, the power pressure chamber 62 is connected to the port 234, and the power pressure chamber is formed on one side of the land 232.

The spool 230 is also provided with rubber valve members 244 and 246 at both longitudinal ends thereof, and the valve members 244 and 246 and the land 23 are attached.
Large-diameter guides 248 and 250 are formed between them and are fitted in the valve hole 228 to guide the movement of the spool 230. A plurality of grooves extending in the axial direction are formed on the outer peripheral surfaces of these guides 248, 250 to allow the flow of brake fluid. Further, an annular groove 254 is formed in a portion of the sleeve 223 corresponding to the land 232 on the inner peripheral surface forming the valve hole 228, and the port 2
Rear wheel cylinders 34, 36
It is connected to the. In the land 232, one of the valve members 244 and 246 of the spool 230 is seated at the open ends of the ports 234 and 238, and one of the communication between the ports 234 and 238 and the master cylinder pressure chamber 236 and the electrically controlled hydraulic chamber 240 is established. When shutting off, the shut-off chamber and port 256,2
The communication with 58 is blocked, and the communication between the chamber not blocked and the ports 256 and 258 is allowed.

The change valve 210 is always in the state shown in FIG. 4, and connects the first pressurizing chamber 22 of the master cylinder 12 with the rear wheel cylinders 34, 36.
The master cylinder hydraulic pressure is supplied to the rear wheel cylinders 34 and 36 in a state where the electric control hydraulic pressure is not supplied from the spool type electromagnetic hydraulic pressure control valve 160. Further, when the electric control hydraulic pressure is supplied from the spool type electromagnetic hydraulic pressure control valve 160, the master cylinder hydraulic pressure is not supplied from the first pressurizing chamber 22, or even if the master cylinder hydraulic pressure is supplied, the master cylinder hydraulic pressure is higher. If it is lower, the spool 230 is moved to the left in FIG. As a result, the electrically controlled hydraulic chamber 240
When the brake fluid flows into the valve member 24, it acts on the land 232 to move the spool 230 further leftward.
4 is seated in the opening of the port 234 to block the communication between the first pressurizing chamber 22 and the rear wheel cylinders 34, 36, while the electrically controlled hydraulic chamber 240 and the rear wheel cylinder 3 are connected.
4, 36 are communicated with each other, and electric control hydraulic pressure is supplied to the rear wheel cylinders 34, 36.

These change valves 210, 212, 2
As shown in FIG. 1, a normally closed electromagnetic on-off valve 270 is provided between the valve 14 and the spool-type electromagnetic hydraulic pressure control valve 160. The spool type electromagnetic hydraulic pressure control valve 160 and the electromagnetic opening / closing valve 270 are controlled by the hydraulic pressure controller 274 via drive circuits 276 and 278. The ECU 146 is connected to the hydraulic pressure controller 274 so that the wheel speed is supplied and the radar 280
Are connected. The radar 280 detects the relative speed and the relative distance between the obstacle and the vehicle, and outputs an ON signal to the hydraulic pressure controller 27 when there is a risk of collision with the obstacle.
Supply to 4.

As shown in FIG. 5, this vehicle is provided with two batteries, a main battery 290 and a sub battery 292. The main battery 290 is a power source common to various electric devices provided in the vehicle, including the spool-type electromagnetic hydraulic pressure control valve 160 and the electromagnetic opening / closing valve 270, and the sub-battery 292 is the spool-type electromagnetic hydraulic pressure control valve. It is a dedicated power source for 160 and the solenoid on-off valve 270.

Main battery 290 to sub battery 2
The switching to 92 is automatically performed when the voltage of the main battery 290 drops or when current is no longer supplied from the main battery 290. For the main battery 290, deterioration of the battery, corrosion of the terminal portion,
The voltage drops due to the full use of electric equipment installed in the vehicle, deterioration of the alternator, failure, etc. Also, the battery terminal is disconnected due to battery damage due to collision etc., cable disconnection, alternator failure, maintenance reasons. As a result, the current is not supplied, and the power cut system 294 is operated so that the current is not supplied.

The power supply cut-off system 294 is adapted to cut off the current supply from the main battery 290 to various electric devices as the automobile collides and the airbag device 300 operates. The airbag device 300 is shown in FIG.
As shown in FIG. 3, an airbag 302, an inflator 304 and an airbag controller 310 are provided. The airbag 302 is built in the pad of the steering wheel, and the inflator 304 generates gas in the gas generating agent 314 by the ignition of the ignition device 312, and the airbag 30 is inflated.
Inflate 2.

The airbag controller 310 includes two front airbag sensors 316, a center airbag sensor 318, a safing sensor 320 and an ignition determination circuit 322. Front airbag sensor 3
The 16 and the safing sensor 320 are turned on and conduct current when a rearward excessive impact is applied to the vehicle due to a frontal collision or the like and a deceleration exceeding a set value occurs. In addition, the center airbag sensor 318
Detects the deceleration linearly, and when the deceleration exceeding the set value occurs, the ignition determination circuit 322 is turned on and the current of the main battery 290 is conducted.

When one of the two front airbag sensors 316 and the safing sensor 320 are turned on, or when the ignition determination circuit 322 and the safing sensor 320 are turned on, a current is supplied to the ignition device 312. When supplied, the gas generating agent 314 is ignited to generate gas, and the airbag 302 is inflated. Even if either the front airbag sensor 316 or the ignition determination circuit 322 is accidentally turned on, the airbag 302 is prevented from inflating.

When a current flows through the ignition device 312 as described above, a voltage difference occurs before and after that. Therefore, this voltage difference is caused by the power cut system 2 by the wirings 324 and 326.
The power cut system 294 simultaneously shuts off the current supply from the main battery 290 to the electric devices.

Main battery 290 and sub battery 29
Switching to 2 will be described with reference to FIG. The voltage of the main battery 290 is supplied to various electric devices 332, 334, 336 and the like by the wiring 330, and a power cut system 294 is provided in the middle of the wiring 330. The voltage of the main battery 290 is also supplied to the operational amplifier 342 by the wirings 338 and 340. The wiring 340 is connected to the spool 340 by the wiring 344.
0 and the solenoid on-off valve 270 are connected, and the wiring 34
The sub-battery 292 is connected by the reference numeral 6. A switch 348 is provided at this connection portion. The switch 348 switches between a state where the wiring 340 is connected to the main battery 290 and a state where the wiring 340 is connected to the sub battery 292.

The voltage supplied to the operational amplifier 342 by the wiring 340 is made into a voltage of a constant height by the stabilizing power supply 352, divided by the resistors 354 and 356, and input to the operational amplifier 342. Also, wiring 3
The voltage supplied by 40 is backed up by the capacitor 358, and the input voltage to the operational amplifier 342 is secured even if the voltage is not supplied within a certain time.

The operational amplifier 342 amplifies the difference between the voltages input from the wirings 338 and 340 and outputs it to the transistor 362 via the resistor 360. Then, when the difference between the currents is equal to or greater than the set value, the transistor 362 becomes conductive, the current is supplied to the coil 364, and the switch 348 is switched. The switch 348 is connected to the main battery 290.
Is normally connected to the main battery 290, the voltage of the main battery 290 is reduced and the current input to the operational amplifier 342 is reduced by the wiring 338. When a current flows through 364, the wiring 340 is switched to the state of being connected to the sub battery 292. This secures the input voltage to the operational amplifier 342 and secures the current supply to the spool type electromagnetic hydraulic pressure control valve 160 and the electromagnetic opening / closing valve 270. The coil 364 has a sub battery 292.
Is reduced to 6V and supplied.

Next, the operation will be described. At the time of non-braking, the electromagnetic directional control valves 110, 112, 124, 132, the electromagnetic hydraulic pressure control valves 120, 122, 126, 128, the electromagnetic opening / closing valve 2
All the solenoids of 70 are demagnetized, the change valves 210 and 212 are in the state shown in FIG. 4, and the master cylinder hydraulic pressure generated in the first and second pressurizing chambers 22 and 24 is the wheel cylinders 34 and 36. It is in a state of being supplied to 42 and 44. Further, the spool type electromagnetic hydraulic pressure control valve 16
No current is supplied to 0, and the control pressure port 170 is in communication with the reservoir 78.

When the brake pedal 26 is depressed during braking, the master cylinder hydraulic pressure is supplied to the front and rear wheel cylinders 34, 36, 42, 44 to suppress wheel rotation.

The brake pedal 2 with respect to the friction coefficient of the road surface
If the stepping force of 6 becomes excessive and the slip state of the wheels exceeds the proper state, anti-skid control is performed. By switching each of the electromagnetic direction switching valves 110, 112, 124, 132, power pressure is supplied to each of the front and rear wheel cylinders 34, 36, 42, 44, and the electromagnetic hydraulic pressure control valve 120 is also provided. , 122, 12
6 and 128 are first switched to the depressurized state so that the front and rear wheel cylinders 34, 36, 42,
The brake fluid in 44 is discharged to the reservoir 78. As a result, if the wheel rotation is restored, the electromagnetic hydraulic control valve 120,
122, 126, 128 are kept in a holding state, and when they are further recovered, they are switched to a pressure increasing state, and the electromagnetic hydraulic pressure control valves 120, 122, 126, 128 are switched to a pressure reducing state, a holding state, and a pressure increasing state, respectively. As a result, the slip ratio of the wheels is kept within the proper range.

Further, if the driving force is excessive at the time of starting acceleration of the vehicle and the slips of the left and right rear wheels 30, 32, which are the driving wheels, become excessive, acceleration slip control is performed. The hydraulic pressure of the accumulator 80 is supplied to the rear wheel cylinders 34, 36 by switching the electromagnetic direction switching valves 124, 132.
The rotation of the wheels is appropriately suppressed by switching the electromagnetic hydraulic pressure control valves 126 and 128 to the pressure increasing state, the holding state and the pressure reducing state, respectively.

When there is a risk of collision between the vehicle and an obstacle during traveling, the hydraulic pressure controller 274 causes the spool-type electromagnetic hydraulic pressure control valve 160 to electrically control liquid based on the ON signal supplied from the radar 280. Generate pressure. The electric control hydraulic pressure generated at this time is the maximum hydraulic pressure that can be generated by the spool type electromagnetic hydraulic pressure control valve 160, and is 100
~ 120 kg / cm ² . At the same time, the solenoid on-off valve 270
The solenoid is excited and opened, and the electric control hydraulic pressure is supplied to the change valves 210, 212 and 214.

At this time, if the brake pedal 26 is depressed and the master cylinder hydraulic pressure higher than the electric control hydraulic pressure is generated, the master cylinder hydraulic pressure is supplied to the wheel cylinders 34, 36, 42, 44. . When the electric control hydraulic pressure is higher than the master cylinder hydraulic pressure or when the brake pedal 26 is not depressed, the electric control hydraulic pressure is supplied to the wheel cylinders 34, 36, 42, 44. In any case, the vehicle is braked and collisions with obstacles are avoided.

When the vehicle is stopped, the hydraulic pressure controller 274 causes the spool type electromagnetic hydraulic pressure control valve 16 to operate.
Reduce the supply current to zero. In this example, the current is reduced to a hydraulic pressure high enough to stop the vehicle on a slope of 30%, i.e. 30-40 kg / cm < ² >. The vehicle is stopped by the hydraulic pressure of 100 to 120 kg / cm ² , which is the maximum hydraulic pressure that can be generated by the spool type electromagnetic hydraulic pressure control valve 160, but this hydraulic pressure is too high to keep the vehicle stopped. It is a value and is decompressed to a height high enough to stop the car.

Therefore, even when the vehicle is stopped by operating the brake even after the vehicle is stopped, the exciting coil 19
The amount of heat generated by 8 is small, and deterioration of the permanent magnet 200 and deterioration of brake component members due to continuous supply of high wheel cylinder hydraulic pressure are prevented. The permanent magnet 200 is an Nd-Fe-B-based magnet that is lightweight and has good magnetic characteristics, but has low heat resistance, and when the spool type electromagnetic hydraulic pressure control valve 160 is downsized and lightweight, the magnet is used. The effect of reducing deterioration can be obtained particularly effectively. Further, if the spool type electromagnetic hydraulic pressure control valve 160 is provided in the engine room, the permanent magnet 200 is heated by not only the heat generated by the exciting coil 198 but also the heat of the engine, and the magnetic force is likely to decrease, so that the permanent magnet 200 is excited. It is particularly effective to suppress the heat generation of the coil 198. Further, the spool type electromagnetic hydraulic pressure control valve 160
If the maximum hydraulic pressure still exists in the accumulator 8, the brake fluid leaks from between the spool 168 and the housing 162 and returns to the reservoir 78.
The pump 92 is frequently operated to return it to 0, but if the fluid pressure is low, the pump 92 can be operated less frequently and energy consumption can be reduced.

During anti-skid control, the ECU
A signal indicating that the anti-skid control is in progress is supplied from 146 to the hydraulic pressure control controller 274, and even if the radar 280 detects the risk of collision during the anti-skid control, the spool-type electromagnetic hydraulic control valve 160 causes the hydraulic pressure to change. Is controlled so that it is not supplied to the wheel cylinders 34, 36, 42, 44. The anti-skid control is performed when the wheel cylinder pressure is excessive,
This is because the vehicle cannot be stopped urgently even if a larger hydraulic pressure is supplied by the spool type electromagnetic hydraulic pressure control valve.

During acceleration slip control, the radar 280
When the risk of collision is detected by the, the electromagnetic directional control valves 124, 132 are switched to a state in which the wheel cylinders 34, 36 are in communication with the change valves 210, 212, and are supplied from the spool-type electromagnetic hydraulic control valve 160. Electric control hydraulic pressure is applied to the wheel cylinders 34, 36, 42, 44.
Is supplied to.

Even if hydraulic pressure is supplied from the spool type electromagnetic hydraulic pressure control valve 160 based on the detection of an obstacle by the radar 280, the automobile collides and the airbag 302 is inflated if an impact force exceeding a set value is applied. , The impact force applied from the steering wheel to the driver's body is reduced.

At the same time when the airbag 302 is inflated, the main battery 29 is removed by the power cut system 294.
The current supply from 0 to various electric devices is cut off. However, the electric current supply to the spool-type electromagnetic hydraulic pressure control valve 160 and the electromagnetic opening / closing valve 270 is not interrupted, so that the electric control hydraulic pressure is maintained in the state of being supplied to the wheel cylinders 34, 36, 42, 44.

An abnormality occurs in the main battery 290, the wiring 338, etc. due to a collision or the like, and the spool type electromagnetic hydraulic control valve 16
0 and the voltage supplied to the solenoid on-off valve 270 decreases,
Alternatively, when the supply is stopped, the switch 348 is switched, the voltage of the sub-battery 292 is supplied to the spool type electromagnetic hydraulic pressure control valve 160 and the electromagnetic opening / closing valve 270, and the electric control hydraulic pressure from the spool type electromagnetic hydraulic pressure control valve 160 is supplied. The vehicle can be braked by the supply of.

After that, when the voltage of the sub-battery 292 drops or is no longer supplied, the spool type electromagnetic hydraulic pressure control valve 160 is in a state in which hydraulic pressure is not supplied. In this case, the electromagnetic opening / closing valve 270 is a solenoid. Since the brake fluid is closed by degaussing, the brake fluid supplied to the wheel cylinders 34, 36, 42, 44 is controlled by the electromagnetic opening / closing valve 270 and the change valves 210, 212.
Enclosed in 6, 42, 44, the brake is kept active.

At this time, when the brake pedal 26 is not depressed, or even if the brake pedal 26 is depressed, if the electric control hydraulic pressure is higher than the master cylinder hydraulic pressure, the change valves 210 and 212 provide the electric control hydraulic pressure. The wheel cylinders 34, 36, 42, 44 are switched to the state of being supplied, and the brake fluid is supplied to the wheel cylinders 34, 36, 4
It is enclosed in 2,44.

If the brake pedal 26 is depressed, the master cylinder hydraulic pressure is higher than the electric control hydraulic pressure, and if the brake pedal 26 is kept depressed even in the event of a collision, the brake fluid will be released to the master. It does not flow out to the reservoir 78 through the pressurizing chamber of the cylinder 12 and is enclosed in the wheel cylinders 34, 36, 42, 44.

Further, even if the brake pedal 26 is depressed, if the pedal force is comparatively small, or if the master cylinder hydraulic pressure is higher than the electric control hydraulic pressure, but the brake pedal 26 is released due to the impact of a collision, The change valves 210 and 212 switch the master cylinder 12 from the wheel cylinders 34, 36, 42 and 44 so as to communicate with the spool type electromagnetic hydraulic pressure control valve 160, and the brake fluid is changed to the change valves 210 and 212 and the electromagnetic opening / closing. The valve 270 allows the wheel cylinders 34, 36,
It is enclosed in 42 and 44.

If a collision occurs in the automobile during the anti-skid control, the electromagnetic directional control valves 110, 112, 12
4, 132 and electromagnetic hydraulic pressure control valves 120, 122, 12
The anti-skid control is released by shutting off the current supply to 6, 128, and the spool-type electromagnetic hydraulic pressure control valve 160 is actuated and the electromagnetic opening / closing valve 270 is opened based on the detection of the collision, and the change valve 210 is opened. , 212 are supplied with electric control hydraulic pressure. Therefore, even if the driver's foot comes off the brake pedal 26 due to a collision, hydraulic pressure is supplied to the wheel cylinders 34, 36, 42, 44, and the vehicle is kept in a stopped state. Further, when an abnormality occurs in the main battery 290 or the sub-battery 292, similarly to the case of the collision during the normal braking, the electric control hydraulic pressure is supplied from the spool type electromagnetic hydraulic pressure control valve 160 and the wheel cylinders 34, The vehicle is kept in a stopped state by filling the brake fluid into 36, 42 and 44.

As is apparent from the above description, in the present embodiment, the spool type electromagnetic hydraulic pressure control valve 160 constitutes a hydraulic pressure control means, and the spool type electromagnetic hydraulic pressure control is performed after the hydraulic pressure controller 274 stops the vehicle. Excitation coil 1 of valve 160
The portion that reduces the current supplied to 98 to reduce the wheel cylinder pressure constitutes the hydraulic pressure control means after the vehicle is stopped.

Although the electromagnetic opening / closing valve 270 is closed when the sub battery 292 is abnormal and the brake fluid is filled therein, even if the sub battery 292 is not abnormal, for example, the wheel cylinder 34, 36, 42,
It may be closed with a sufficient electrical control fluid pressure supplied to 44 to keep the vehicle stationary. In this way, the vehicle can be kept in a stopped state, the amount of current supplied to the spool-type electromagnetic hydraulic pressure control valve 160 can be reduced to 0, and the life of the permanent magnet 200 can be further extended.

Another embodiment of the present invention is shown in FIG. In this embodiment, when the brake pedal 370 is stepped on, the wheel cylinder 374 is generated in the pressurizing chamber of the master cylinder 372.
The hydraulic pressure supplied to is electrically controlled.

An electromagnetic directional control valve 380 is provided in the liquid passage 378 connecting the master cylinder 372 and the wheel cylinder 374. The electromagnetic directional control valve 380 is connected to the reservoir 384 by the reservoir passage 382. When the solenoid is demagnetized, the master cylinder 372 communicates with the wheel cylinder 374, and the wheel cylinder 374 is energized by the solenoid.
Connect to 4. The relief valve 3 is provided in the reservoir passage 382.
86 is provided to discharge the brake fluid in the wheel cylinder 374 to the reservoir 384 when the wheel cylinder fluid pressure is higher than the relief pressure. The relief pressure is set to a hydraulic pressure value required to keep the vehicle stationary.

The electromagnetic directional control valve 380 is switched by the hydraulic pressure controller 388. A rotation speed sensor 390 that detects the rotation speed of the wheels is connected to the hydraulic pressure controller 388. When the wheel speed becomes 0 and the vehicle stops, the solenoid of the electromagnetic directional control valve 380 is excited to brake fluid. Are discharged to the reservoir 384. The brake fluid pressure is reduced by the relief valve 386 to the hydraulic pressure value required to keep the vehicle stationary, thus keeping the vehicle stationary. If you do this, the wheel cylinder fluid pressure will be low even if you continue to brake the vehicle after stopping,
It is possible to reduce deterioration of the brake component. In the present embodiment, the electromagnetic directional control valve 380 and the relief valve 386 constitute hydraulic pressure control means, and the hydraulic pressure control controller 388 constitutes hydraulic pressure control means after the vehicle is stopped.

In the embodiments shown in FIGS. 1 to 6, the spool type electromagnetic hydraulic pressure control valve 160 is designed to supply hydraulic pressure to the wheel cylinders only when there is a risk of collision with the vehicle and only at the time of collision. However, the present invention can also be applied to a brake device in which normal braking is performed by supplying hydraulic pressure electrically controlled by a spool-type electromagnetic hydraulic pressure control valve. In this case, when the spool type electromagnetic hydraulic pressure control valve 160 or its control means is equipped with a master cylinder, the rotation of the wheels can be suppressed by the hydraulic pressure generated in the master cylinder based on the depression of the brake pedal. It is normal to do so, but it is not indispensable to install a brake device with two electric / manual systems,
The manual brake system may be omitted.

Further, in the embodiments shown in FIGS. 1 to 6, the vehicle is automatically braked when there is a risk of collision, but the vehicle may be braked for reasons other than the risk of collision. The present invention can be applied to a brake device that automatically brakes the vehicle and keeps the brake in the operating state by continuously supplying the hydraulic pressure to the wheel cylinder even after the vehicle is stopped.

Further, in the embodiment shown in FIGS. 1 to 6, the exciting coil 19 of the spool type electromagnetic hydraulic pressure control valve 160 is used.
8 is designed to reduce the current supplied to the wheel cylinder 8 to lower the wheel cylinder hydraulic pressure after the vehicle is stopped. In addition to the spool type electromagnetic hydraulic pressure control valve 160, the electromagnetic directional control valve 380 and the relief valve shown in FIG. 386 may be provided. For example, when the master cylinder hydraulic pressure is supplied to the wheel cylinder, the brake fluid in the wheel cylinder is discharged to the reservoir via the relief valve to reduce the wheel cylinder hydraulic pressure.

Further, in the embodiment shown in FIGS. 1 to 6, the hydraulic pressure is not supplied from the spool type electromagnetic hydraulic pressure control valve 160 even if there is a risk of collision with the vehicle during the anti-skid control. However, if there is a risk of collision during anti-skid control, the spool-type electromagnetic hydraulic control valve 1
The hydraulic pressure may be controlled by 60 and the solenoid opening / closing valve 270 may be opened to supply the hydraulic pressure to the wheel cylinders 34, 36, 42, 44. Even if a high hydraulic pressure is supplied from the spool type electromagnetic hydraulic pressure control valve 160, the electromagnetic hydraulic pressure control valve 12
This is because the height is controlled to an appropriate height by 0, 122, 126, 128, and there is no problem.

Further, in the above-mentioned embodiment, the hydraulic pressure after the vehicle is stopped is set to such a value that the vehicle can be kept stopped when the gradient of the road surface is 30%. Is not limited to a fixed size, and can be set in various ways, for example, by detecting the gradient of the road surface and setting the value according to the gradient of the road surface.

Further, in the above embodiment, the normally closed electromagnetic on-off valve 270 is provided between the change valves 210, 212, 214 and the spool type electromagnetic hydraulic pressure control valve 160. A valve may be provided. If a normally open electromagnetic on-off valve is used, for example, when there is a risk of collision as in the above embodiment, hydraulic pressure is supplied to the wheel cylinders by hydraulic pressure control means such as a spool type electromagnetic hydraulic pressure control valve, and the vehicle is The hydraulic pressure can be sealed in the wheel cylinder by closing the hydraulic cylinder in a state in which the hydraulic pressure necessary to maintain the stopped state is supplied. Further, it is not limited to the case where the brake fluid is supplied to the wheel cylinders by the hydraulic pressure control means regardless of the driver's intention, and when the hydraulic pressure supplied to the wheel cylinders is insufficient due to the driver's operation of the brake operation member. Hydraulic pressure is supplied to the hydraulic pressure control means, and after the vehicle is stopped, the solenoid valve is closed and the brake fluid is sealed while the hydraulic pressure necessary to keep the vehicle stopped is supplied to the wheel cylinder. You can In any case, after closing the electromagnetic opening / closing valve, the hydraulic pressure control means can be brought into the hydraulic pressure non-supply state, and it is not necessary to operate it more than necessary, and the life can be improved.

Further, the hydraulic pressure control means is not limited to the spool type electromagnetic hydraulic pressure control valve, but any hydraulic pressure control means capable of electrically controlling the hydraulic pressure can be adopted.

In addition, 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 of a hydraulic brake device that is an embodiment of the present invention.

FIG. 2 is a front sectional view showing a master cylinder and a hydraulic booster of the hydraulic brake device.

FIG. 3 is a front cross-sectional view showing a spool-type electromagnetic hydraulic pressure control valve provided in the hydraulic brake device.

FIG. 4 is a front sectional view showing a change valve of the hydraulic brake device.

FIG. 5 is a diagram showing a switching circuit between a main battery and a sub battery of the hydraulic brake device.

FIG. 6 is a diagram showing an airbag device provided in an automobile equipped with the hydraulic brake device.

FIG. 7 is a system diagram of a hydraulic brake device according to another embodiment of the present invention.

[Explanation of symbols]

 34,36 Rear wheel cylinder 42,44 Front wheel cylinder 80 Accumulator 160 Spool type electromagnetic hydraulic pressure control valve 274 Hydraulic pressure control controller 374 Wheel cylinder 380 Electromagnetic directional control valve 386 Relief valve 388 Hydraulic pressure control controller

Claims (1)

[Claims] 1. A wheel cylinder of a brake for braking a vehicle, a hydraulic pressure control means for electrically controlling the hydraulic pressure of the wheel cylinder, and a hydraulic pressure of the wheel cylinder required to stop the vehicle at a predetermined value or more. In some cases, the brake device includes a post-vehicle-stop hydraulic pressure control unit that controls the hydraulic pressure control unit after the vehicle is stopped so that the wheel cylinder hydraulic pressure is equal to or less than the predetermined value.