JPH09329267A - Solenoid valve and brake device using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To hold opening condition of a flow passage even when current is cut after one end flow passage is opened by arranging a positioning mechanism for holding a condition in which an input port and an output port are communicated and not communicated with each other, on a spool. SOLUTION: When electric trouble is generated, a cut valve is not operated, and a sensor is detected a condition in which a master cylinder and a hydraulic chamber are closed; current is transferred from an electric control device to a solenoid valve 40 for a short time, a push rod 46 is operated, a spool 42 is moved, and an input port 44 and an output port 45 are communicated with each other. Simultaneously therewith, hold of this communicating condition is kept holding since a stopped 51 is fit to a second notch 50. As a result, liquid pressure generated in a master cylinder is supplied to a hydraulic chamber through the opening solenoid valve 40 so as to obtain a normal brake condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic valve (fail safe valve) suitable for a brake device for controlling a wheel lock that occurs when a sudden brake (during rapid pressurization) is applied to a vehicle brake and the like. It relates to the braking device used.

[0002]

2. Description of the Related Art In recent years, various antilock control devices (brake devices) have been actively developed for the purpose of improving the steering stability during braking and facilitating the driver's driving operation. . In such an antilock control device, a pressure adjusting piston is arranged in a hydraulic pressure chamber defined in the brake caliper, and the hydraulic pressure chamber is shut off from the master cylinder by a shutoff valve during antilock control. There is a system in which the pressure piston is advanced and retracted by a cam mechanism to realize antilock control while controlling the volume of the hydraulic chamber.

However, in the above antilock control device, when the valve (electromagnetic valve) that shuts off the hydraulic pressure chamber and the hydraulic pressure source during the antilock control becomes inoperable due to a failure or the like, the minimum condition is the master. There is no corresponding piping route that can directly introduce the hydraulic pressure from the cylinder into the hydraulic chamber,
There are many safety issues.

[0004]

Therefore, in the present invention, even if the valve (solenoid valve) that shuts off the hydraulic pressure chamber and the hydraulic pressure source (master cylinder) fails, the minimum condition from the master cylinder is as a minimum condition. By providing an electromagnetic valve (fail-safe valve) that allows hydraulic pressure to be directly introduced into the hydraulic chamber (actuator), it is intended to realize a brake system with even higher safety. The electromagnetic valve according to the present invention is
Detecting the failure of the valve (solenoid valve) that shuts off the hydraulic pressure chamber and the hydraulic pressure source, opens the flow path, and once the flow path is opened, the current will flow even if the current is cut. It is possible to keep the passage open, and even if the valve fails due to this, the minimum condition is that the hydraulic pressure from the hydraulic pressure source (master cylinder) can be directly introduced into the hydraulic chamber (actuator). There is.

[0005]

For this reason, the technical solution adopted by the present invention comprises a main body, a spool slidably provided in the main body, and a solenoid for operating the spool. , An input port and an output port are formed, and when the solenoid is not energized, the input port and the output port are brought into a non-communication state, and when the solenoid is energized, the spool moves to move the input port and the output port. In the electromagnetic valve communicating with the electromagnetic valve, the spool is provided with a positioning mechanism capable of maintaining a state in which the input port and the output port are in communication and in a non-communication state. And

A cylinder formed in the caliper of the brake device, a slidable brake piston arranged in the cylinder, a hydraulic chamber defined by the piston in the cylinder, and a hydraulic chamber arranged in the hydraulic chamber. Pressure regulating mechanism,
A cut valve arranged in a flow path that communicates the hydraulic chamber and the master cylinder, an electromagnetic valve arranged in a pipe provided in parallel with the cut valve, and an electronic control device that controls the pressure adjusting mechanism ( In the brake device including an ECU, the solenoid valve causes the spool to move by energizing a solenoid so that the input port and the output port communicate with each other, and the communication state is continuously maintained by the positioning mechanism. It is a brake device characterized in that

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a configuration diagram of a brake device as an embodiment according to the present invention in which a pressure adjusting mechanism is incorporated in a brake caliper, FIG. 2 is an enlarged sectional view of a pressure adjusting mechanism portion in FIG. 1, and FIG. FIG. 4 is a sectional view of the electromagnetic valve.

In FIG. 1, 1 is a master cylinder, 2
Is a normally open cut valve, 3 is a pressure adjusting mechanism (details will be described later), 4 is a brake piston, 5 is a disk pad provided on the brake piston, 6 is a motor for driving the pressure adjusting mechanism, and 7 is an electronic control device. (ECU) 10 is a brake caliper, 12 is a hydraulic chamber partitioned within the caliper, 30 is a hydraulic pressure sensor, 31 is an alarm device, 32 is a potentiometer, 3
Reference numeral 3 is a speed sensor, 40 is a normally closed electromagnetic valve disposed in a pipe provided in parallel with the cut valve 2, and these constitute a brake system.

As shown in FIG. 1, the cut valve 2 is provided with a shaft 2a that comes into contact with a cam surface 24a provided on a gear 24 that drives the pressure adjusting mechanism 3. When the gear 24 rotates, the shaft 2a is rotated by the cam surface 24a. 2a is pushed to the left in the drawing to close the cut valve 2. Note that this valve may be an electromagnetic valve that can close the flow path in response to a command from the electronic control unit. The pressure adjusting mechanism 3 arranged in the hydraulic pressure chamber 12 in the caliper 10 includes a cam case 13 fixed to the caliper 10 by a screw 14 and a cam rotatably arranged in the cam case 13 as shown in FIGS. Shaft 1
5, cams 22a and 22b provided on the camshaft 15, pressure adjusting pistons 20a and 20b that are in contact with the cams 22a and 22b via rollers 23a and 23b, a gear 24 fixed to the camshaft 15, and a gear 24. The pinion 25 meshes with the motor 6, the motor 6 for driving the pinion 25, the flexible boot 26 covered by the cam case 13, and the like.

In the pressure adjusting mechanism 3, when the cam shaft 15 is rotated counterclockwise in FIG.
2a, 22b adjusts the pressure regulating piston 20 to the cam case 1
3, the boot 26 is deformed and the hydraulic pressure in the hydraulic chamber 12 can be reduced. The roller 23
a and 23b are rotatably provided on the pressure adjusting piston 20, and by this roller, the cam 22a and the pressure adjusting piston 2 are provided.
The friction with 0 is reduced.

As shown in FIG. 4, the electromagnetic valve 40 includes a main body 41 and a spool 42 slidably provided in the main body 41.
And a solenoid 43 for operating the spool, and the main body includes an input port 44 communicating with a hydraulic pressure source (master cylinder) and an actuator (wheel cylinder).
An output port 45 that communicates with is formed. A push rod 46 is arranged in the center of the solenoid 43, and a spring 47 for urging the push rod 46 to the right in the drawing is arranged between the push rod 46 and the main body 41. The aforementioned spool 42 is slidably arranged in the main body so as to face the above.

The spool 42 is formed with a groove 48 for connecting and disconnecting the input port 44 and the output port 45, and two notches 4 for positioning the spool 42.
9 and 50 are formed. The notches 49 and 50 are a first notch 49 for positioning the spool 42 in the non-operating state and a second notch 50 for positioning the spool 42 in the operating state.
Each notch 49, 50 has a stopper 51 provided on the body 41 side.
Are fitted with these notches 49, 50
The stopper 51 constitutes a spool positioning mechanism. The positioning mechanism is not limited to the combination of the notch and the stopper, and any mechanism can be adopted as long as it has the same effect.

When the electromagnetic valve 40 is not in operation (when no failure has occurred), the stopper 51 is fitted in the first notch 49 with the spring 47 bent as shown in FIG. At this time, the spool 42 blocks the communication between the input port 44 and the output port 45. When the solenoid 43 is energized, the solenoid 4
The push rod 42 moves to the position shown in FIG. 5 by the magnetic force generated by 3 and the biasing force of the spring 47, and the spool 42 also moves accordingly, and the stopper 51 is fitted into the second cutout 50. In this state, the spool 42
The groove 48 formed at 2 communicates the input port 44 and the output port 45, and this state is maintained even if the current stops flowing to the solenoid 43 after that because the stopper 51 is fitted in the second cutout 50. In this manner, in this electromagnetic valve, if sufficient energization is first secured to move the spool 42, the subsequent operating state is continuously maintained by the positioning device, so the solenoid capacity for operating the spool can be made small. There are merits such as. Further, this electromagnetic valve can be returned to the initial state (non-operating state) again only by pushing the spool after the operation.

The operation of the brake device having the above structure will be described. [During Normal Braking] During normal braking, the cut valve 2 does not operate because the motor 6 does not operate without a command from the electronic control unit 7. In addition, the cam 22 in the pressure adjusting mechanism 3
Reference characters a and 22b have the initial positions shown in FIGS.
Therefore, in this state, when the brake pedal is depressed to generate hydraulic pressure in the master cylinder 1, this hydraulic pressure is supplied to the hydraulic pressure chamber 12 through the master cylinder 1 → the open cut valve 2 → the flow passage 30 and the brake is applied. The piston 4 is moved to execute the braking action. At this time, the pressure regulating piston 20a,
20b does not move because the camshaft 15 does not rotate. When the depression of the brake pedal is released, the brake fluid in the hydraulic chamber is returned to the master cylinder in the route opposite to the above, and the brake is released.

[Anti-Lock Control] When the brake pedal is depressed to brake the vehicle, the master cylinder 1
Causes hydraulic pressure. This hydraulic pressure is supplied to the hydraulic chamber 12 in the brake device as described above, and moves the brake piston 4 to apply a braking force to the wheels. By the way, in this state, the state of the wheel is always detected by the speed sensor 33 and the like, and the detection signal is input to a known electronic control unit, and the electronic control unit inputs the wheel speed, the slip rate, the reduction rate based on the input. Calculate speed etc. Then, the skid state of the wheels is evaluated based on this calculation result, and the cut valve 2 and the motor 6 are controlled as described below to execute various modes such as depressurization, holding, and repressurization of the brake fluid pressure.

That is, when the wheels are locked during traveling and the brake release signal is output from the electronic control unit (ECU) 7, the motor 6 is driven and the gear 2 is passed through the pinion 25.
Rotate 4. As the gear 24 rotates, the cam surface 24a
The cut valve 2 is closed by the
5 rotates counterclockwise in FIG. Camshaft 15
With the rotation of the rollers 23a and 23b, the rollers 23a and 23b follow the cams 22a and 22b while rotating, and accordingly, the pressure adjusting pistons 20a and 20b gradually sink into the cam case 13. As a result, the boot 25 is driven by the hydraulic pressure in the hydraulic chamber 12.
While deforming, the volume in the hydraulic chamber 12 increases, the brake hydraulic pressure is reduced, the braking force is weakened, and the locked state of the wheels is released.

Further, at the time of repressurization, when the motor 6 is rotated in the reverse direction and the camshaft 15 is rotated in the direction of the initial position, the pressure adjusting pistons 20a and 20b are pushed back into the hydraulic chamber 12 and repressurization is executed. . Further, when a command for holding the brake fluid pressure is issued, the motor 6 stops and holds the brake fluid pressure in the fluid pressure chamber.

The control of the motor 6 is appropriately performed by the detection signals from the hydraulic pressure sensor 30, the potentiometer 32, the speed sensor 33, etc., and the hydraulic pressure control (pressure reduction, holding, repressurization) of the brake device is performed. This is performed independently or for each wheel of each channel according to the state of each wheel. The release of the antilock control is performed when there is no signal from the electronic control unit. That is, when the signal from the electronic control unit disappears, the motor 6 rotates in the reverse direction to open the cut valve 2, the cams 22a and 22b return to the initial position, and the pressure adjusting pistons 20a and 20b also return to the initial position. As shown in FIG. 1, the normal braking state is established.

[At the time of failure] If a motor or other electrical failure occurs during the above-described antilock control and the cut valve does not work and the master cylinder and the hydraulic chamber remain disconnected, a normal braking state is established. There is a safety problem because you cannot recover. Therefore, in this example, when this state is detected by the sensor, a short-time current (signal current) is caused to flow from the electronic control unit to the electromagnetic valve 40, and the push rod 46 is operated to move the spool 42 to the state shown in FIG. 44 and the output port 45 are brought into communication with each other. At the same time, stopper 5
Since 1 is fitted in the second cutout 50, this communication state is continuously maintained, and as a result, even if the cut valve remains in the cutoff state, the hydraulic pressure generated in the master cylinder is opened. It is supplied to the hydraulic pressure chamber via the electromagnetic valve that is present, and the normal braking state can be obtained. Also,
The operating state of the electromagnetic valve 40 can be notified to the driver via the alarm 31. It should be noted that the current flowing through the electromagnetic valve 40 is sufficient to move the spool to the state shown in FIG. 5, so that it is sufficient for a short time, and the solenoid capacity can be reduced accordingly, and further, after the operation, the spool can be pushed in. Can return to the initial state (non-operating state) again.

As described above, in the brake device, when the motor is driven by various sensors to activate the pressure adjusting mechanism and antilock control, traction control, automatic brake control, etc. are being executed, the cut valve temporarily fails. Even if the above occurs, the electromagnetic valve can immediately connect the master cylinder and the hydraulic chamber, so that an extremely safe brake device can be obtained. The electromagnetic valve is
It can be used not only in the brake device but also in other hydraulic pressure control circuits as a matter of course, and is configured as a highly versatile device.

[0021]

As described in detail above, in the electromagnetic valve according to the present invention, since the positioning mechanism is provided on the spool, once the flow path is opened, the flow path can be kept open after that, and the solenoid is energized. You don't have to continue. Therefore, the capacity of the solenoid used for the electromagnetic valve can be reduced and the current used can be reduced, which can contribute to the reduction in size and weight of the electromagnetic valve (faef safe valve). Further, the reliability of the electromagnetic valve is improved, and when the failure is resolved, the electromagnetic valve can be used again only by pushing the spool into the initial state, which is economical. Excellent operational effects can be achieved.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a brake device as a first embodiment according to the present invention.

FIG. 2 is an enlarged sectional view of the pressure adjusting mechanism in FIG.

FIG. 3 is a sectional view taken along line AA in FIG. 2;

FIG. 4 is a cross-sectional view showing a non-operating state of an electromagnetic valve.

FIG. 5 is a cross-sectional view showing an operating state of an electromagnetic valve.

[Explanation of symbols]

 1 hydraulic pressure generation source (master cylinder) 2 cut valve 3 pressure regulating mechanism 4 brake piston 5 disc pad 6 electric motor 7 electronic control unit 10 caliper 12 hydraulic chamber 13 cam case 15 camshaft 20a, 20b pressure regulating piston 22a, 22b cam 23a, 23b Roller 25 Boot 40 Electromagnetic valve 41 Main body 42 Spool 43 Solenoid 44 Input port 45 Output port 49, 50 Notch 51 Stopper

Claims (3)

[Claims] 1. A body 41, a spool 42 slidably provided in the body 41, and a solenoid 4 for operating the spool.
3, an input port 44 and an output port 45 are formed in the main body, and when the solenoid is not energized, the input port and the output port are brought into a non-communication state, and the solenoid is energized to spool the spool. In the electromagnetic valve that moves the input port and the output port to communicate with each other, the spool is capable of maintaining a state in which the input port and the output port are in communication with each other, and the communication mechanism is in a non-communication state. 51 is provided, the electromagnetic valve. 2. A cylinder 11 formed in a caliper of a brake device, a slidable brake piston 4 arranged in the cylinder 11, and a hydraulic chamber 12 defined in the cylinder 11 by the piston. A pressure adjusting mechanism 3 arranged in the hydraulic pressure chamber 12, and a flow passage 30 that connects the hydraulic pressure chamber 12 and the master cylinder.
Brake device including a cut valve 2 disposed inside, an electromagnetic valve 40 disposed in a pipe provided in parallel with the cut valve 2, and an electronic control unit (ECU) 7 that controls the pressure adjusting mechanism. In the electromagnetic valve 40, the solenoid is energized to move the spool so that the input port and the output port communicate with each other, and the communicating state is continuously maintained by the positioning mechanism. apparatus. 3. The brake device according to claim 2, wherein the cut valve 2 is configured to open and close the valve by a cam surface 24a formed on a gear 24 that operates a pressure adjusting mechanism.