KR920007026B1 - Solenoid valve for braking hydraulic control of automobile anti-lock brake system - Google Patents

Abstract

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Description

Solenoid valve for braking hydraulic control of automobile anti-lock brake system

FIG. 1 is a general configuration diagram of an anti-lock brake device to which the present invention is applied, and FIG. 1a is a configuration diagram of a brake device using two two-port / 2 position valves.

FIG. 1B is a block diagram of a brake device in which one 3-port / 3 position valve is used. FIG.

Figure 2 is a longitudinal cross-sectional view and symbol showing the configuration and operation of the three-port / three-position valve according to the present invention, Figure 2a is a view of the operation and preference of the current is not applied to the solenoid coil.

Figure 2b is a function and preference of a state in which a low current is applied to the solenoid coil.

Figure 2c is a diagram showing the action and preference of a high current is applied to the solenoid coil.

Figure 3 is a longitudinal cross-sectional view and symbol showing the configuration of a conventional three port / three position valve.

* Explanation of symbols for main parts of the drawings

11: solenoid coil 12: yoke

12a: distribution hole 13: cylinder

14: first plunger 15: second plunger

14a, 15a: push rod 15b: spring

16: 1st check valve 17: 2nd check valve

16a, 17a: check ball 16c, 17b: spring

P, T, A: Connection port G1, G2: Attack

The present invention relates to a braking hydraulic pressure control solenoid valve of an antilocking brake system that electronically controls braking hydraulic pressure acting on a hydraulic brake of an automobile.

If you brake suddenly on a slippery road while driving a car, the rolling of the tire will stop immediately by the brakes attached to each wheel.However, if the friction force on the road is too small, As a result, it slides on the road as it is. This phenomenon is referred to as the tire is locked. When this locking phenomenon occurs, the friction between the tire and the road surface is further decelerated to increase the braking distance, and in this state, there is a fatal risk that steering of the front wheel is impossible even if the steering wheel is operated. do. Moreover left. If braking occurs due to sudden braking in the situation that the frictional force acting on the right tire is different, an unexpected situation may occur such as braking and the vehicle body turning sharply at the same time.

Therefore, a device for automatically controlling the braking pressure of the hydraulic brake so that the tire does not occur due to excessive brake operation by the driver under any driving condition and road surface condition is an antilocking brake device. The present invention relates to a solenoid valve for controlling the braking hydraulic pressure of a brake device.

Representative basic configuration of the electronically controlled anti-locking brake device developed to date is as shown in Figure 1a, the braking hydraulic pressure acting on the brake cylinder (2) of each wheel (1) according to the signal of the electronic controller (3) Two two-port / 2-position solenoid valves S1 and S2 for each brake of the wheel 1 for control to increase, decrease or maintain, one for each brake as shown in FIG. It is known to use a three port / 3 position solenoid valve (S3). In the drawings, reference numeral 5 denotes a brake pedal, 6 a vacuum booster, 7 a master cylinder, 8 an oil tank, and 9 a speed controller.

When the electric two-port / 2-position solenoid valves (S1) and (S2) are used, the solenoid valve which leads to the inlet of the hydraulic pump (4) when the current applied to each solenoid valve (S1) and (S2) is cut off simultaneously. As the S2 is closed and the solenoid valve S1 connected to the discharge port of the hydraulic pump 4 is opened, the brake oil is forcibly supplied to the brake cylinder 2 to increase the brake hydraulic pressure of the brake.

When the current is applied only to the solenoid valve S1 under the above conditions, the supply and discharge of the brake oil in the brake cylinder 2 is blocked, so that the braking hydraulic pressure is kept constant at the pressure just before the operation of the solenoid valve S1. However, if current is applied to each solenoid valve S1 and S2 at the same time, the solenoid valve S1 is closed and the solenoid valve S2 leading to the inlet of the hydraulic pump P is opened. The brake oil is sucked by the hydraulic pump 4 so that the braking pressure is quickly reduced.

In this two-port / 2-position method, since each solenoid S1 and S2 have only an opening and closing function, the structure is relatively simple. However, two solenoid valves are required for each wheel brake. Therefore, the amount of use of the solenoid valve was increased.

On the other hand, in the case of using the later three-port / 3-position solenoid valve S3, if the current applied to the solenoid valve S3 is set in two stages and the current is not applied to the solenoid valve S3, the brake When the A port on the cylinder (2) side and the P port on the discharge side of the pump (4) are connected to each other, the braking pressure is increased, and when the low current of the first stage is applied to the solenoid valve (S3), the hydraulic pump (4) and the brake All flow paths between the cylinders 2 are blocked and the braking pressure is kept constant.When two high currents are applied, the A port on the brake cylinder 2 side and the T port on the suction port side of the pump 4 are connected. The braking pressure is reduced. In this type of operation, the three-way conversion is possible by using a single solenoid valve. Therefore, the number of solenoid valves used for each wheel is reduced. .

However, the three-port / 3 position solenoid valve 20 used in such a conventional brake device has one end of the plunger 22 installed inside the cylinder 21 as shown in FIG. Two poppet valves 25a and 25b which are elastically installed and elastically installed by the spring 24 having a weaker elasticity than the spring 23, and the plunger 22 has a solenoid coil 26 If no current is applied to the spring 23, the plunger 22 is moved to the right by a predetermined distance to maintain the attack (G) at a predetermined interval between the yoke 27 and the plunger 22 and at the same time (22) As the poppet valve 25b inside, the T port side flow path 28b is closed, and the P port side flow path 28a on the opposite side is opened, and brake oil is supplied to the brake cylinder 2 as described above. In this state, the solenoid coil 26 When a constant current flows, the plunger 22 is moved to the left by a predetermined distance while compressing the spring 23 by the magnetic force generated in the attack G on the side of the P port flow path 28a. Since the P port side flow path 28a is closed as 25a), the P port and T port and A port side flow paths 28a, 28b, and 28c are all shut off, and the brake cylinder 2 is closed. Maintain braking hydraulic pressure.

In addition, when a high current of two levels is applied to the solenoid coil 26, the plunger 22 is completely applied to the yoke 27 by the magnetic force generated in the attack (G) between the yoke 27 and the plunger 22. When the T port side flow path 28b is opened, the braking oil flowing through the A port side flow path 28c is moved to the T port 28b to reduce the braking hydraulic pressure acting on the brake cylinder 2. It is structured to be made.

However, in such a conventional three-port / 3-position valve, operation grooves 22a and 22b are provided inside the plunger 22 to limit the movement widths of both poppet valves 25a and 25b. It requires precise dimension processing to be performed, and the two-stage operation of the plunger 22 as described above is sequentially performed within the attack (G) range between the plunger 22 and the yoke 27 to maintain a small distance. Therefore, if the amount of current applied to the solenoid coil 26 at each operation step does not exactly match the required reference current amount, there is a possibility that a malfunction may occur, and the high pressure is applied through the blocked poppet valves 25a and 25b. There was a problem such as oil leakage from the side to the low pressure side.

Therefore, the main object of the present invention is to provide a solenoid valve for braking hydraulic pressure control of an anti-locking brake device which does not have all the problems described above.

Another object of the present invention is to arrange two plungers having a push rod on both sides of the yoke formed in the middle portion of the cylinder chamber, and one ball plunger valve which is opened and closed by the push rods on one side of the plunger and the pump side, respectively. By operating two plungers independently according to the amount of current applied to one solenoid, the leakage of oil is completely eliminated when the flow path between each port is completely eliminated, and the direction of plunger for opening and closing of the valve is quickly and accurately achieved. The present invention provides a solenoid valve for braking hydraulic pressure control of an anti-locking brake device.

The solenoid valve of the present invention for achieving the above object will be described in detail with reference to the accompanying drawings.

2a, 2b and 2c are cross-sectional and symbol views showing the configuration and operation of the three-port / 3 position solenoid valve 10 according to the present invention. As shown therein, the solenoid valve according to the present invention is a solenoid. The inner middle portion of the hollow tube having yokes 12 generating suction magnetic force in accordance with the current applied to the coil 11 having discharge ports and suction port connection ports P and T of the hydraulic pump 4 at both ends. A cylinder 13 having a connection port A connected to the brake cylinder 2 on a circumferential wall of the pipe adjacent to the pump discharge port side connection port P, and a push rod 14a having a predetermined length. ), (15a) is provided at the center of the cylindrical body with both ends open and at a predetermined distance on both sides of the yoke 12 so that they can be operated independently according to the strength of the suction force generated in the yoke 12 First and second plungers 14 and 15 disposed respectively; It is provided in each of the connection port (P) and the first plunger 14 so as to open and close the distribution hole (12a) formed in the center of the hydraulic pump discharge port side connection port (P) and the yoke (12). And first and second check valves 16 and 17.

The cylinder 13 is a valve in which the check ball 17a of the second check valve 17 built in the first plunger 14 is in contact with one side of the distribution hole 12a formed at the center of the yoke 12. The sheet 12b is formed.

The first and second plungers 14 and 15 provided on both sides of the yoke 12 of the cylinder 13 are springs 17b of the second check valve 17 provided inside the first plunger 14. ) And a spring 15b inside the second plunger 15, each of which is provided at a predetermined distance on both sides of the cylinder 13 while being elastically installed in the outward direction with respect to the yoke 12 in the middle thereof. The stop ring 18a, 18b restricts movement in the outward direction, so that the intermediate yoke 12 and the first plunger 14 and the second plunger 15 on both sides thereof have different sizes. Attacks G1 and G2 with narrow and wide widths are maintained.

Further, the push rods 14A and 5a provided in the first and second plungers 14 and 15 as described above are supported by 14c of the outer end center portions of the plungers 14 and 15, respectively. One end is fixed to each of the first and second push rods 14a and 15a, and the circulation holes 16b and 12a formed in the first check valve 16 and the yoke 12 are respectively fixed to the first and second push rods 14a and 15a. Each of the first and second check valves 16 and 17 can be closed or opened according to the movement of each of the plungers 14 and 15.

On the other hand, the first check valve 16 has a valve seat 16d on which the check ball 16a is seated and a distribution hole 16b located inside the brake port and the cylinder 2 side connection port A. The spring 16c that elastically supports the check ball 16a has a smaller elasticity than the spring 17b of the second check valve 17 embedded in the first plunger 14.

Effects of the present invention solenoid valve configured as described above are as follows.

2a shows a state in which no current flows through the solenoid coil 11, and in this state, the first plunger 14 and the second plunger 15 are provided with springs 17b and 15b provided therein. (G1) having a narrow and wide width between the yoke 12 and the inner ends of the both side plungers 14 and 15, respectively, with the elasticity of , G2 are formed respectively, and the check seat 16a of the first check valve 16 is pressed as the push rod 14a of the first plunger 14 to press the valve seat 16d and the flow hole 16b. In the open state, the check ball 17e of the second check valve 17 installed inside the first plunger 14 is in contact with the valve seat 12b of the yoke 12 to close the flow hole 12a. You are in a blocked state.

Therefore, in this state, the connecting port A connected to the brake cylinder 2 is connected to the connecting port P connected to the discharge port of the hydraulic pump 4, and the connecting port is connected to the suction port of the hydraulic pump 4. Since the haute T is blocked, the brake oil discharged from the hydraulic pump 4 is supplied to the brake cylinder 2 to increase the braking hydraulic pressure of the brake.

When the low current of the first stage flows through the solenoid coil 11 in the above state, the agent which maintains the attack G1 close to the yoke 12 by the magnetic force which generate | occur | produces in the yoke 12 of the cylinder 13 is made. Since the one plunger 14 is moved to the right as shown in FIG. 2B, the right end thereof contacts the yoke 12 and moves the push rod 14a fixed to the plunger support 14c in the same direction. The flow hole 16b is sealed by the check ball 16a of the first check valve 16 pressed by the push rod 14a.

Therefore, in such a state, since the discharge port side connection port P and the suction port side connection port T of the hydraulic pump 4 are simultaneously blocked, the braking hydraulic pressure acting on the brake cylinder 2 is kept constant.

On the other hand, when the high current of the second stage is applied to the solenoid coil 11 in the above state, as shown in FIG. 2c, the second plunger 15 moves to the left while compressing the spring 15b. And the check ball 17 of the second check valve 17 sealing the flow hole 12a of the yoke 12 is pushed as the push rod 15a while the left end thereof is in contact with the yoke 12. Since the opening 12a is opened, the brake port 2 side connection port A and the hydraulic pump 4 suction port side connection port T communicate with each other to reduce the braking pressure applied to the brake cylinder 2. It is to be made.

As described above, the present invention provides a three-port / 3-position solenoid valve for electronically controlling the braking hydraulic pressure of an anti-locking brake device of a vehicle, the yoke generating magnetic force by a current applied to the solenoid coil. It is installed in the middle of the cylinder and two plungers are arranged on both sides of the yoke, and two check valves which are opened and closed respectively according to the operation of both plungers are connected to the one plunger and the outlet of the hydraulic pump side. The two plungers can be operated independently according to the strength of the current applied to the solenoid coil of the valve. Therefore, the overall structure of the valve is simple and the processing and assembling of the parts can be easily performed to improve productivity and reduce manufacturing costs. Oil leakage from high pressure side to low pressure side It does not occur at all, it is possible to increase the reliability of the valve by changing the direction of the plunger for the opening and closing operation of the valve quickly and accurately.

Claims (3)

A yoke 12 for generating a attracting magnetic force in accordance with the current applied to the solenoid coil 11 is provided in the inner middle portion of the hollow tube having both the discharge port and the suction port side connection ports P and T of the hydraulic pump at both ends. And a cylinder 13 having a brake cylinder side connection port A formed on the circumferential wall of the pipe adjacent to the pump discharge port side connection port P, and push rods 14a and 15a having a predetermined length. It is provided at the center of each of the cylindrical body elastically supported by (17b), (15b) and are respectively disposed on both sides of the yoke 12 so that they can be operated independently according to the strength of the suction force generated in the yoke 12 The first and second plungers 14 and 15 and the connection port P to open and close the pump discharge port side connection port P and the distribution hole 12a at the center of the yoke 12; It consists of the first and second check valves 16, 17 which are respectively installed in the first plunger 14, said one For braking hydraulic pressure control of a vehicle anti-lock brake device, characterized in that the solenoid coil 11 enables two plungers 14 and 15 to be operated independently to enable a 3-port / 3 position changeover. Solenoid valve. The check valve (16a) of claim 1, wherein the spring (17b) for elastically supporting the check ball (17a) of the first plunger (14) and the second check valve (17). A solenoid valve for braking hydraulic pressure control of an anti-locking brake device for a vehicle, characterized in that it has a stronger elasticity than a spring (16c) for supporting it. The first plunger 14 of claim 1, wherein the first plunger 14 disposed on one side of the yoke 12 of the cylinder 13 maintains an attack G1 having a predetermined width between the yoke 12 and the second plunger. A braking hydraulic pressure control solenoid valve of an anti-locking brake device for a vehicle, characterized by maintaining a greater attack (G2) than the attack (G1) between the (15) and the yoke (12).

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