JPH08121635A - Solenoid valve - Google Patents

Abstract

PURPOSE: To prevent the production of noise caused by the occurrence of pressure fluctuation even if a valve seat side through-hole and a valve body side through-hole are placed in the mutually cut-off state or almost cut-off state by applying a current to a solenoid. CONSTITUTION: A valve seat 53b is formed opposedly to a valve ball 54 fixed to the small diameter part of a rod 51, and a stopper member 55 is disposed concentrically with the valve seat 53b, in a relatively movable state. A coil spring 56 with a small spring constant is disposed in the compressed state between the flange part 55a of the stopper member 55 and the upper end face of a valve seat forming member 53, and a pair of coned disc springs 57a, 57b are disposed between the flange part 55a and the step part of the rod 51. When a current flows to a solenoid, the lower end of the stopper member 55 comes in contact with the valve seat forming member 53, and the rod 51 moves receiving the spring force of the coned disc springs 57a, 57b so as to obtain a quasi- cut-off state. A clearance between the valve ball 54 and the seat 53b functions as a throttle, and when the valve ball 54 in contact with the valve seat 53b, a cut-off state is obtained, and noise comes to almost naught.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve, and more particularly to a solenoid valve most suitable for hydraulic control of an antiskid controller for preventing wheel lock.

[0002]

2. Description of the Related Art FIG. 3 is a piping system diagram of a conventional anti-skid control device. In the figure, two hydraulic pressure generating chambers are defined in a cylinder body 3 of a master cylinder 1 and a brake is formed. By stepping on the pedal 4, hydraulic pressure is generated in these. These are transmitted to the wheel cylinders of the left front wheel FL and the right rear wheel RR through the conduits 5a and 5b and the inlet valves 17a and 17b. Further, the pipelines 5a and 5b are branched from the pipelines 6a and 6b,
Similar inlet valves 20a, 20b are also connected to these, and are connected to the wheel cylinders of the right front wheel FR and the left rear wheel RL. Further, the wheel cylinders of these wheels have outlet valves 23a, 23b and 24, respectively.
It is connected to the loosening pipe lines 8a and 8b via a and 24b.
It is further connected to low pressure reservoirs 25a, 25b.
This has a known structure, and a relatively spring-biased piston is slidably fitted in the casing.
The brake fluid storage chamber is connected to the suction side of the hydraulic pump 10.

The hydraulic pump 10 is constructed in a known manner,
It comprises a motor 11, an eccentric mechanism 12, and check valves 15a, 15b and 13a, 13b, and a pair of plungers reciprocates in opposite directions, whereby the check valves 13a, 13b.
The valve b is opened to supply the pressurized liquid to the conduits 5a and 5b.

Although not shown, wheel speed sensors are connected to the wheels FL, FR, RL, RR, and when the vehicle equipped with this device is running, the rotational speeds of these wheels are detected. Is also supplied to a control unit (not shown). The control unit has a well-known configuration, and evaluates the skid state of these wheels to determine the switching valves 17a, 17b, 20a, 20b, 23 described above.
The solenoids a, 23b, 24a, and 24b are selectively excited.

To make the explanation easier to understand, it is assumed that all four wheels are in the same skid state. First, when the brake pedal 4 is stepped on, the pressure fluid from the master cylinder 1 flows through the pipe line 5a
5b inlet valves 17a, 17b, 20a, 20b
Is transmitted to the wheel cylinders of the wheels FL, FR, RL, RR, and the brakes are applied. The control unit determines that the brake should be held depending on road conditions or how the brake pedal 4 is depressed. Inlet valves 17a, 17b, 20a and 2
The solenoid part of 0b is excited. As a result, each solenoid valve is switched to the shutoff position. As a result, the hydraulic fluid is confined in the wheel cylinder of each wheel, and the braking force is kept constant. Then, when it is determined that the brake should be released, the outlet valves 23a, 23a
The solenoids b, 24a and 24b are also excited. The hydraulic fluid in the wheel cylinder of each wheel passes through the pipe lines 8a and 8b to release the brake.

When the control unit determines that the valve should be reloaded, stepwise loading is performed in this conventional example, the solenoid portions of the outlet valves 23a, 23b, 24a and 24b are de-energized and the inlet valve 17a,
The solenoids 17b, 20a and 20b are excited intermittently. As a result, the hydraulic pressure in the wheel cylinder of each wheel increases stepwise.

The hydraulic pressure of the wheel cylinder is controlled as described above, and FIG. 5 shows the change situation.
When the brake pedal 4 is depressed at time t ₀ , the hydraulic pressure P of the wheel cylinder increases, the braking force is kept constant at time t ₁ , the braking force is reduced at time t ₂ , and the stairs are tucked at t _3. Although the start, is held for a short time constant until t ₄ t _4, t ₅ between the inlet valve 17a, 17b, 2
The solenoids 0a and 20b are not excited. In the same manner, stairs are inserted as illustrated.

The anti-skid control is performed as described above, but the inlet valves 17a, 17
When the solenoid portions b, 20a, 20b are excited to switch the communication state to the cutoff state, the brake fluid from the master cylinder 1 side is cut off with a certain momentum. In addition, these inlet valves 17a, 17b, 2
The time for switching 0a and 20b from on to off is 1 ms.
When the brake fluid having a kinetic energy as short as ec or less is cut off, hydraulic pressure pulsation occurs because it is cut off in such a short time, and this is transmitted to the vehicle body and is annoying to the driver as noise. Has become. That is, when the flow of the liquid in the pipe is rapidly interrupted, the kinetic energy of the brake fluid is converted into pressure energy as described above, and this pressure fluctuation reciprocates in the brake pipe at a substantially sonic speed. And the equipment connected to it,
For example, noise is generated by vibrating the master cylinder 1 and members supporting the same. In order to create a comfortable driving environment, we want to reduce such noise as much as possible.

Next, conventional inlet valves 17a, 1
A specific configuration of 7b, 20a, 20b will be described with reference to FIG. These have the same configuration. In the inlet valve 17a in FIG. 4, the bobbin 32 is attached to the coil support member 30, and the electromagnetic coil 33 corresponding to the solenoid portion is wound around the bobbin 32.
There is a casing 36 and a body 35 along the inner peripheral axis of the coil 33, and the solenoid portion is the coil casing 3
Bound by 1. Casing 36 and body 35
The axial hole of the armature 34 slides by the electromagnetic force.
And a rod 37 that moves via the armature 34 is axially guided and slidably fitted. An O-ring 38 and a cup seal 39 are provided on the peripheral surface of the lower guide member 35.
3 is fitted in the casing block, which is integrated with the other inlet valves 17a, 17b, 20a, 20b and outlet valves 23a, 23b, 24a, 24b and the hydraulic pump 10 in FIG. It works closely. A steel valve ball 44 is caulked and fixed to the lower end portion of the rod 37, which faces the valve seat 40b formed at the upper end portion of the valve seat forming member 40 in the axial direction of the rod 37 with a valve lift. are doing. Also,
A coil spring 4 is provided between the rod 37 and the valve seat forming member 40.
5 is stretched, and the rod 37 is urged upward in the drawing to take the illustrated upper position. The through hole 40a of the valve seat forming member 40 communicates with the conduit connected to the master cylinder side, that is, the conduit 5a in FIG. 3, and the valve in the lower body 35 in which the valve ball 44 is disposed. The chamber 42 is in communication with the wheel cylinder side, that is, the pipe line 7a side in FIG. The conventional inlet valve 17a is configured as described above. However, when an excitation signal is supplied from the control unit to the electromagnetic coil 33 as a solenoid portion, the armature 34 receives a magnetic attraction force downward and the rod 37 also. The valve ball 44 is moved downward and seated on the valve seat 40b, and the valve ball 44 fixed to the tip of the valve ball shuts off the master cylinder side and the wheel cylinder side.
As described above, since this switching time is as short as 1 msec, the kinetic energy possessed by the brake cylinder flows from the master cylinder side to the wheel cylinder side so that the kinetic energy of the brake fluid changes to pressure fluctuation. It is converted and pulse pressure is generated between it and the master cylinder side. At the same time, pulse pressure is generated between the wheel cylinder and the wheel cylinder. This is transmitted to the vehicle body, and as described above, it is annoying to the driver as noise.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide a solenoid valve that reduces noise during anti-skid control.

[0011]

The above object is to provide a valve in which an electromagnetic coil, an armature slidably arranged on the central axis of the electromagnetic coil, and a rod are connected in series and fixed to one end of the rod. A body, a valve seat disposed with a predetermined valve lift in the moving direction of the rod, a first through hole formed on the valve seat side, and a second through hole formed on the valve body side. A spring means for urging the valve body or the rod in a moving direction of the rod in a direction away from the valve seat, the valve body is urged by the spring means when the electromagnetic coil is not energized. The first through hole and the second through hole communicate with each other by being separated from the valve seat, but when the electromagnetic coil is energized, a magnetic attraction force is applied to resist the spring force of the spring means and the rod. To the valve seat side so that the valve body is seated on the valve seat, In the solenoid valve capable of blocking the first through hole and the second through hole, the spring means includes a first spring having a small spring constant and a second spring having a large spring constant and is movable with the rod. However, this is achieved by an electromagnetic valve characterized in that a stopper member is provided, which comes into contact with the stationary portion when moved by a predetermined distance smaller than the valve lift and prevents further movement.

[0012]

[Function] When the electromagnetic coil is energized, the armature is attracted and the rod moves at the same time, and the rod moves quickly to a predetermined distance by a spring force with a small spring constant, and the valve element fixed to the rod end approaches the valve seat. . If this distance is exceeded, the spring force of the second spring, which has a large spring constant, mainly acts, and if the current value is the same, the moving speed becomes small, and in some cases, the valve lift stops with a small clearance in the valve lift, And the master cylinder side. Therefore, the flow velocity of the brake fluid on the master cylinder side can be suppressed. After that, depending on the current value, the wheel cylinder side and the master cylinder side are completely shut off by overcoming the strong spring force of the second spring and sitting on the valve seat, but the kinetic energy of the brake fluid is already small. Therefore, even if the master cylinder side is cut off thereafter, a large pressure fluctuation will not occur. Also, when stair-stepping is performed, this solenoid valve is used as an inlet valve, and shut-off / communication is repeated. By switching this, the current value sent to the coil, that is, the solenoid part can be switched between two levels of strength and weaker than valve lift. By repeating a small clearance and seating, stairs can be inserted without transmitting a large pressure fluctuation to the master cylinder side and the wheel cylinder side. That is, the noise can be greatly reduced or eliminated as compared with the conventional one.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An inlet valve used in an anti-skid control device in a solenoid valve according to an embodiment of the present invention will be described below.

In FIG. 1, a main part of the inlet valve is shown as an enlarged cross-section at 50, but other configurations not shown are exactly the same as the conventional example. A slidable rod 51 is arranged in a valve body 52, which is stepped, but a valve ball 5 made of steel is provided at the tip of the small diameter portion 51a.
4 is caulked and fixed as shown. The valve seat forming member 53 fitted and fixed in the axial hole formed in the valve body 52 has a through hole 5 communicating with the master cylinder side.
3a is formed, and a conical valve seat 53b is formed on the upper end portion. This is opposed to the above-mentioned valve ball 54 with a valve lift s.

A cylindrical stopper member 55 is concentrically arranged outside the small diameter portion 51a of the rod 51, and a coil spring having a small spring constant is provided between the flange portion 55a and the valve seat forming member 53. 56 is provided and biases the stopper member 55 upward in a compressed state. In addition, a pair of disc springs 5 are provided between the flange portion 55a and the step portion of the rod 51.
A spring portion 57 having a large spring constant composed of 7a and 57b is arranged, and the disc springs 57a and 57b are arranged so that their inner surfaces face each other with a space of f therebetween.
It becomes the stroke of. In addition, a plurality of round holes 55b are formed on the peripheral wall surface of the stopper member 55 to facilitate communication between the valve chamber 60 in which the valve ball 54 is disposed and the through hole 53a and the wheel cylinder side. ing. Although FIG. 1 shows a state in which the solenoid portion or the electromagnetic coil is not energized, the distance between the lower end portion 55c of the stopper member 55 and the upper end surface of the valve seat forming member 53 is a distance e smaller than the valve lift s. Further, the above-mentioned disc springs 57a, 57
The gap f between b is smaller than this s.

The inlet valve 50 of this embodiment is constructed as described above, and its operation will be described below.
Although not shown in FIG. 1, when the current I ₀ is applied to the electromagnetic coil disposed above, the armature (34 in FIG. 4) made of a magnetic material is attracted toward the body 52 by the downward magnetic attraction force. The rod 51 moves downward. Since the spring constant of the coil spring 56 is sufficiently smaller than the spring force of the disc springs 57a and 57b, the disc springs 57a and 57b are hardly deformed, only the coil spring 56 is compressed and deformed, and the rod 51 is quickly moved downward. When the lower end portion 55c of the stopper member 55 moves by the distance e, the stopper member 55 comes into contact with the valve seat forming member 53 and is prevented from moving further.

FIG. 2 shows the relationship between the electromagnetic force and the moving distance of the rod 51 when the current I ₀ is passed.
When moving the distance e between the valve ball 54 and the valve seat 53b, which is the initial position shown in FIG. 1, that is, the distance e from the valve lift s, the electromagnetic force changes as shown in the figure, and after moving the distance e. The rod 51 is moved downward by deforming the disc springs 57a and 57b. In the present embodiment, moving this f causes the disc springs 57a and 57b to come into substantial contact, but at this time, the valve lift s is moved. The valve lift s is designed as shown in FIG.
It moves, that is, the valve ball 54 is seated on the valve seat 53b.
Accordingly, the through hole 53a of the valve seat forming member 53, that is, the valve chamber 6 communicating with the master cylinder side and the wheel cylinder side.
It is cut off from 0 .

According to the present embodiment, the current is further switched in two steps of strength and weakness, that is, the weaker current I ₁ . As a result, the rod 51 moves upward due to the spring force, and the electromagnetic force at the current I ₁ at this time and the disc spring 57
The rod 51 stops at a position balanced with the spring forces of a and 57b, that is, at a distance g (smaller than f), but at this time, the gap between the valve ball 54 and the valve seat 53b is as small as g. , This allows this inlet valve 50
Acts as a throttle, so to speak, to decelerate the high-speed brake fluid that has been flowing from the master cylinder side. In the present embodiment, this switching is further repeated to repeat the valve ball 54 and the valve seat 53.
The gap with b is changed to 0, g, 0, g .... Therefore, although the cutoff state is not continuously maintained, the energy of the brake fluid having large kinetic energy is kept small while the cutoff state is kept small, and the pressure fluctuation applied to the vehicle body is made small, and the noise is made small or not. be able to.

Further, the stopper member 55 is the valve seat forming member 5
After contacting No. 3, the brake fluid from the through hole 53a is transmitted to the wheel cylinder side through the round hole 55b, so that the contact does not suddenly block the flow of brake fluid. . Further, when the solenoid portion is not energized, the distance e between the lower end portion 55c of the stopper member 55 and the valve seat forming member 53 is relatively small as shown in the figure, so that the liquid from the master cylinder side to the wheel cylinder side is Although the amount is slightly narrowed depending on this, free communication is possible because the round hole 55b is formed.

As described above, according to the inlet valve 50 of this embodiment, the large noise generated when the solenoid portion is excited to disconnect the master cylinder side from the wheel cylinder side can be reduced to almost zero.

The embodiments of the present invention have been described above.
Of course, the present invention is not limited to this, and various modifications can be made based on the technical idea of the present invention.

For example, in the above embodiment, the pair of disc springs 57a and 57b are provided as springs having a large spring constant, and the distance between the inner surfaces is set to f. However, instead of this, one disc spring 57a or 57b is used. Alternatively, the distance between the inner surface and the upper end surface of the flange portion 55a of the stopper member 55 may be set to f using only the above.

In the above embodiment, a pair of disc springs 57 are used.
Although a and 57b are used, a coil spring having a similar spring characteristic, for example, a wave spring may be used instead, and a coil spring having a large spring constant may be used instead.

In the above embodiment, the intensity of the current flowing through the solenoid is switched in two steps. However, by changing the current I ₁ , the position g where the electromagnetic force and the disc spring force are balanced can be freely set. Therefore, the current is not limited to the two-stage switching, but may be switched between the three-stage and the four-stage so as to change the cutoff state or the throttle state between the master cylinder side and the wheel cylinder side. After a certain amount of electric current is applied to the disc springs 57a and 57b, the spring force acts on the disc springs 57a and 57b. You may make it a state.

In the above embodiments, the valve ball 54 is used as the valve body and the conical seat surface 53b formed at the tip of the valve seat forming member 53 is used as the valve seat. The present invention is also applicable to such a valve body, for example, one in which a ring member made of rubber is used as a valve seat on the outer peripheral edge portion of the end surface of the rod and the opening end portion of the through hole 53a opposed thereto.

Further, in the above embodiment, the invention is applied to the inlet valve used in the anti-skid control device.
However, the present invention is not limited to this, and it is also possible to suppress the pressure transmission that occurs in either one side or the other side that is interrupted by using a normal hydraulic pressure control device.

[0027]

As described above, according to the solenoid valve of the present invention, even if it is used in an anti-skid control device and a current is passed through the electromagnetic coil to bring it into a shut-off state or a nearly shut-off state, a large It does not cause vibrations in the vehicle body due to pressure fluctuations, and enables driving with a good feeling.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a main part of an inlet valve used in an anti-skid control device according to an embodiment of the present invention.

FIG. 2 is a chart for explaining the operation of the inlet valve.

FIG. 3 is a piping system diagram of a conventional antiskid control device.

FIG. 4 is an enlarged sectional view of the inlet valve in the same piping system diagram.

FIG. 5 is a time chart explaining the same operation.

[Explanation of symbols]

 50 Inlet Valve 51 Rod 53b Valve Seat 54 Valve Ball 55 Stopper Member 56 Coil Spring 57a Disc Spring 57b Disc Spring

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masakazu Machida 2-5-2 Mama, Ichikawa City, Chiba Prefecture

Claims (2)

[Claims] 1. An electromagnetic coil, an armature slidably arranged on the central axis of the electromagnetic coil, and a rod are connected in series, and a valve element fixed to one end of the rod and a predetermined direction in the moving direction of the rod. A valve seat arranged with the valve lift of
A first through hole formed on the valve seat side, a second through hole formed on the valve body side, and the valve body or the rod are attached in a direction of moving away from the valve seat in the moving direction of the rod. When the electromagnetic coil is not energized, the valve element is separated from the valve seat by the urging force of the spring means to connect the first through hole and the second through hole. However,
When the electromagnetic coil is energized, the rod is moved to the valve seat side against the spring force of the spring means by a magnetic attraction force, so that the valve body is seated on the valve seat, and the first through hole is formed. In the electromagnetic valve capable of blocking the second through hole, the spring means is composed of a first spring having a small spring constant and a second spring having a large spring constant, and is movable with the rod. An electromagnetic valve provided with a stopper member that comes into contact with a stationary portion when a predetermined distance smaller than the lift is moved and is prevented from moving further. 2. A current having a first strength is passed through the electromagnetic coil to seat the valve body on the valve seat, and immediately thereafter a current having a second strength smaller than the first strength is switched. Then, the rod is moved away from the valve seat so that the distance between the valve body and the valve seat is smaller than the difference between the valve lift and the predetermined distance, and then the current is immediately applied. 2. The switching to the first strength, the valve body to be seated on the valve seat, and thereafter, the current is switched between the first strength and the second strength at a predetermined timing.
Solenoid valve described in.