KR100575600B1 - Solenoid valve for brake traction control system - Google Patents

Abstract

The present invention relates to a brake traction control system that prevents road slippage of wheels, and in particular, the valve opens by itself when excessive braking pressure is applied to the wheels by the operation of the hydraulic pump so that the braking pressure can be reduced.

A solenoid valve for a brake traction control system according to the present invention for this purpose is coupled to the shaft hole formed in the longitudinal direction in the interior of the armature so that one end of the plunger, which is retractably installed in the valve core, in the armature, and the outside of the plunger inside the shaft hole. And a safety spring for pressurizing the plunger toward the inlet of the valve core, a first supporting jaw integrally provided on the inner surface of the shaft hole of the amateur so that one end of the safety spring is caught, and a second support formed on the outer surface of the plunger so that the end of the safety spring is supported. And a fixing member coupled to the outer surface of the plunger such that one end of the plunger having passed through the portion where the first supporting jaw is formed is caught by the first supporting jaw.

Description

Solenoid valve for brake traction control system {SOLENOID VALVE FOR BRAKE TRACTION CONTROL SYSTEM}

1 is a hydraulic circuit diagram of an anti-lock brake system to which a conventional traction control system is applied.

2 is a hydraulic circuit diagram of an anti-lock brake system to which a solenoid valve for a traction control system according to the present invention is applied.

3 is a cross-sectional view showing the configuration of a solenoid valve for a traction control system according to the present invention.

4 is a detailed view of portion 'A' of FIG. 3.

5 is a plan view showing the configuration of a fixing member according to the present invention.

Explanation of symbols on the main parts of the drawings

20: master cylinder, 24: NO solenoid valve,

25: NC solenoid valve, 26: hydraulic pump,

27: low pressure accumulator, 28: high pressure accumulator,

29: reciprocating hydraulic valve, 30: TC solenoid valve,

31: valve core, 32: valve dome,

33: amateur, 33a: axial,

33b: first support jaw, 34: female coil,

35: plunger, 35b: second support jaw,

35c: coupling groove, 36: valve seat,

37: restoring spring, 39: safety spring,

40: fixing member.

The present invention relates to a brake traction control system that prevents road slippage of a vehicle wheel, and more particularly, a brake to open a valve by itself when an excessive braking pressure is applied to a wheel by a hydraulic pump. A solenoid valve for a traction control system.

Among the brake systems for vehicles, there is an anti-lock brake system (hereinafter referred to as 'ABS') that prevents road slippage by periodically regulating the braking pressure transmitted to the wheel side.

As shown in FIG. 1, the vehicle ABS has a NO (normally open) solenoid valve 3 installed in the middle of a hydraulic line connected from a master cylinder 1 to a wheel cylinder 2 on a wheel side, and on a wheel side. An NC (Normal Close) solenoid valve (4) provided in a return flow path for returning oil is provided. In addition, ABS has a hydraulic pump (5) for re-pressurizing the oil returning from the wheel side to generate a braking pressure, the low pressure accumulator (6) accumulating the oil circulating upstream and downstream of the hydraulic pump (5) And a high pressure accumulator 7 are respectively installed. In addition, these devices are controlled by an ECU (not shown), and the ECU controls the opening and closing of the NO and NC solenoid valves 3 and 4 to control the braking pressure supplied to the wheel side. The driving of the hydraulic pump 5 is controlled to re-pressurize the fluid returned along the hydraulic line to the wheel side so that intermittent braking is achieved.

In addition, the recently developed vehicle ABS includes a basic ABS configuration as described above, and a brake traction control system (BTCS: BRAKE) that prevents slippage of wheels and road surfaces when the vehicle starts and starts so that the vehicle starts smoothly. Some of them further include a TRACTION CONTROL SYSTEM.

The traction control system has a separate first bypass passage 8a which connects the outlet side hydraulic line of the master cylinder 1 and the inlet side hydraulic line of the hydraulic pump 5. In addition, the first bypass passage 8a is provided with a reciprocating hydraulic valve 8 which maintains an open state and closes the flow path when the driver presses the brake pedal 1a and the braking pressure is transmitted. In addition, the hydraulic line 9a connecting the outlet side of the master cylinder 1 and the outlet side of the high-pressure accumulator 7 is a traction control solenoid valve 9, hereinafter referred to as a `` solenoid valve for TC ''. Is installed). In addition, a pressure control valve 10 is installed in the second bypass passage 10a connecting the outlet side of the master cylinder 1 to the outlet side of the high pressure accumulator 7.

Such a traction control system operates when a slip phenomenon of a vehicle wheel is detected regardless of the driver's operation of the brake pedal 1a. That is, when the slip of the wheel is detected in the process of starting the vehicle, the hydraulic pump 5 is driven by the control of the ECU, and the braking pressure is applied to the wheel cylinder 2 on the wheel side. At this time, since the TC solenoid valve 9 and the NC type solenoid valve 4 remain closed, oil at the outlet side of the master cylinder 1 is supplied to the hydraulic pump 5 through the reciprocating hydraulic valve 8. The hydraulic pump 5 pressurizes the brake so that the wheel is braked. In this operation, when the outlet braking pressure of the hydraulic pump 5 is too high, the pressure regulating valve 10 is opened so that the oil is diverted through the second bypass passage 10a, so that the braking pressure applied to the wheel side is always appropriate. Is maintained.

However, such a conventional brake traction control system includes a separate second bypass passage 10a to prevent the pressure on the outlet side of the hydraulic pump 5 from being excessively increased, and the second bypass passage 10 includes a hydraulic pump 5. When the pressure on the outlet side is higher than necessary, the brake system is not only complicated, but also has a problem that the volume of the device is large because it is provided with a separate pressure control valve 10 for opening the second bypass passage.

The present invention is to solve such a problem, an object of the present invention is to open the TC solenoid valve when the outlet pressure of the hydraulic pump is more than the predetermined pressure to allow the oil to flow to the master cylinder to separate the bypass flow path and pressure It is to provide a solenoid valve for a brake traction control system that enables the braking pressure of the hydraulic pump outlet side to be properly maintained without a control valve.

A solenoid valve for a brake traction control system according to the present invention for achieving this object is a valve core having a longitudinal through hole formed in the center and an inlet and an outlet for fluid flow, and coupled to one end of the valve core. The armature is installed in the valve dome retractable, the excitation coil is provided on the outside of the valve dome to advance and retract the amateur, and the penetration of the valve core to open and close the inlet of the valve core in conjunction with the retraction movement of the amateur A solenoid valve for a brake traction control system having a plunger removably installed in a ball and a restoring spring for returning the plunger and the amateur to open the valve core when the excitation coil is not powered. Remind the plunger to enter and retract therein A shaft hole formed in the longitudinal direction in the amateur, and a safety spring coupled to the outside of the plunger inside the shaft hole for pressing the plunger toward the inlet of the valve core, integral with the inner surface of the shaft hole of the arm such that one end of the safety spring is caught The first support jaw provided by the first support jaw, the second support jaw formed on the outer surface of the plunger so that the end of the safety spring is supported, and one end of the plunger passing through the portion formed with the first support jaw is caught on the first support jaw It characterized in that it comprises a fixing member coupled to the outer surface of the plunger to be supported.

In addition, the present invention is characterized in that the elasticity of the safety spring is larger than the elasticity of the restoring spring.

In addition, the outer surface of the plunger to which the fixing member is coupled is characterized in that the coupling groove of a predetermined depth is formed so that the fixing member is fitted.

In addition, the fixing member is characterized in that the snap ring capable of stretching the inner diameter.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 2, the vehicle ABS to which the present invention is applied is installed in the middle of a hydraulic line connected from the master cylinder 20 to the wheel-side wheel cylinder 23 and is a NO (normally open) solenoid valve for opening and closing a flow path. 24, and an NC (Normal Close) solenoid valve 25 for opening and closing the oil flow path returned from the wheel side. At this time, when the NO type solenoid valve 24 is opened, the NC type solenoid valve 25 is closed to apply a braking pressure to the wheel side, and when the NO type solenoid valve 24 is closed, the NC type solenoid valve 25 is opened to the wheel. Is configured to release the braking pressure.

In addition, the ABS includes a hydraulic pump 26 for repressurizing oil returned from the wheel-side wheel cylinder 23 to an upstream flow path of the NO solenoid valve 24, and the upstream and downstream flow paths of the hydraulic pump 26 are The low pressure accumulator 27 and the high pressure accumulator 28 which are respectively installed in the buffer space BUFFER are provided. At this time, the low pressure accumulator 27 installed upstream of the hydraulic pump 26 functions to temporarily store the brake oil returning from the wheel side and then supply the hydraulic fluid to the hydraulic pump 26, and downstream of the hydraulic pump 26. The high pressure accumulator 28 installed at the side functions to attenuate the pressure pulsation according to the operation of the hydraulic pump 26 while temporarily storing the pressurized oil in the hydraulic pump 26. And these devices are controlled by the ECU (ELECTRIC CONTROL UNIT, not shown). That is, the ECU controls the NO-type and NC-type solenoid valves 24 and 25 so that the flow path supplied to the wheel side is opened and closed, and the low pressure accumulator 27 is provided through the flow path that returns by controlling the driving of the hydraulic pump 26. The oil flowing toward the wheel is re-pressurized to the side of the wheel for intermittent braking.

In addition, ABS is equipped with a brake traction control system (BTCS) that prevents slippage of wheels and road surfaces when the vehicle starts and stops smoothly.

The traction control system has a separate bypass passage 29a for connecting the outlet side hydraulic line of the master cylinder 20 and the inlet side hydraulic line of the hydraulic pump 26. The bypass passage 29a is normally provided with a reciprocating hydraulic valve 29 which closes the flow path when the driver presses the brake pedal 22 and the braking pressure is transmitted. This normally causes the braking pressure to be applied toward the wheel cylinder 23 of the wheel when the driver steps on the brake pedal 22.

In addition, the hydraulic line connecting the outlet side of the master cylinder 20 and the outlet side of the high-pressure accumulator 28 is normally kept open, and the hydraulic pump 26 is closed by closing the flow path when a road surface slip of the wheel occurs due to a sudden start of the vehicle. TC solenoid valve 30 is installed to allow the braking pressure generated by the driving of the wheel to be transferred to the wheel side. At this time, the solenoid valve for TC 30 according to the present invention is to open a valve by itself when the pressure of the hydraulic pump 26 outlet side flow path is more than a predetermined pressure so that a part of the oil can flow toward the master cylinder (20).

As shown in FIG. 3, the TC solenoid valve 30 has a longitudinal through hole 31c formed at a center thereof, and an inlet 31a and an outlet 31b for inflow and discharge of oil at a lower end thereof. The provided magnetic valve core 31 is provided. And the upper portion of the valve core 31 is covered with a valve dome 32 provided in a thin cylindrical shape is coupled. Inside the valve dome 32, a cylindrical armature 33 having a shaft hole 33a formed in the center thereof is provided, and this armature 33 is installed to allow a predetermined section to move forward and backward in the longitudinal direction. And the outer side of the valve core 31 and the valve dome 32 is provided with a cylindrical excitation coil 34 for advancing the armature 33 by receiving power.

Further, a rod-shaped plunger 35 capable of advancing and retracting in the longitudinal direction is provided in the valve core 31 through-hole 31c. The plunger 35 extends up and down so that one end is adjacent to the valve seat 36 provided on the inlet 31a side of the valve core 31 and the other end is in the state of entering the shaft hole 33a of the armature 33. do. In addition, the sphere 35a which blocks the flow of oil by blocking the flow path of the valve seat 36 when the plunger 35 moves forward by the operation of the armature 33 at the lower end of the plunger 35 adjacent to the valve seat 36. Is coupled, and when the power is not applied to the excitation coil 34 between the lower end of the plunger 35 and the valve seat 36, the restoring spring 37 for retracting the plunger 35 and the amateur 33 to open the flow path ) Is installed.

Inside the shaft hole 33a of the armature 33 into which the upper portion of the plunger 35 enters, as shown in FIG. 4, the first supporting jaw protrudes in a form in which the inner diameter is reduced to have a step, and has a predetermined width up and down. 33b is provided. In addition, the upper portion of the plunger 35 entering the inside of the shaft hole (33a) is provided with a second support jaw (35b) to form a step by reducing the outer diameter toward the top. The upper end of the shaft hole 33a is supported by the first supporting jaw 33b of the armature 33 and the lower end of the plunger 35 so that the plunger 35 has the force of restoring toward the valve seat 36. The safety spring 39 is supported on the support jaw (35b) is installed.

The upper outer surface of the plunger 35 extending further through the portion where the first supporting jaw 33b is formed, prevents the plunger 35 from being separated from the shaft hole 33a of the armature 33 and at the same time, the safety spring The fixing member 40 is coupled so that the plunger 35 is caught and supported by the upper portion of the first supporting jaw 33b in a state where the extension of the 39 is limited. At this time, the fixing member 40 is composed of a conventional snap ring capable of expansion and contraction of the inner diameter, as shown in Figure 5, the fixing member 40 on the upper outer surface of the plunger 35 of the portion to which the fixing member 40 is coupled. A coupling groove 35c of a predetermined depth is formed along the outer surface so that the fitting may be coupled to each other. This configuration is to facilitate the coupling of the armature 33 and the plunger 35 in a state in which the safety spring 39 is built by making the mounting of the fixing member 40 easily inside the shaft hole 33a.

In constructing the TC solenoid valve 30, the elasticity of the safety spring 39 described above is greater than the elasticity of the restoring spring 37 installed on the valve seat 36 so that the safety spring when the armature 33 is operated. It should be possible for the 39 to overcome the elasticity of the restoring spring 37 and to push the plunger 35. When the sphere 35a of the plunger 35 is in contact with the valve seat 36 and the inlet 31a of the valve core 31 is applied with the passage closed, the pressure of this oil is a safety spring 39 By pushing the plunger 35 to overcome the elasticity of the valve, the fluid must flow into the gap between the valve seat 36 and the sphere 35a. This allows the fluid pressure at the outlet side of the hydraulic pump 26 to be determined by the elastic force of the safety spring 39.

The following describes the operation of the vehicle ABS to which the solenoid valve for TC of this configuration is applied.

When the driver presses the brake pedal 22, the back pressure is generated by the pressure difference in the power supply unit 21, the braking pressure is formed by receiving the amplified force in the master cylinder 20, this hydraulic pressure is a solenoid valve NO It is supplied to the wheel cylinder 23 of each wheel side through 24, and exhibits a braking force. At this time, when excessive braking pressure is transmitted, a slip phenomenon occurs that the tire of the vehicle stops rotating and slips on the road surface. This slip phenomenon is detected by a wheel sensor (not shown) mounted on the wheel side of the vehicle, and the detected information is detected. It is delivered to an ECU (not shown). At this time, the ECU releases the NC solenoid valve 25 to allow the oil in the wheel cylinder 23 to escape, thereby releasing the temporary braking to prevent slippage.

In addition, the oil escaping through the NC-type solenoid valve 25 is moved to the low pressure accumulator 27 and stored for a while, and the oil of the low pressure accumulator 27 is re-pressurized by the driving of the hydraulic pump 26 and the high pressure accumulator 28 ) And the oil of the high pressure accumulator 28 is supplied to the upstream side of the NO-type solenoid valve 24 to form a braking pressure. This operation is to be repeatedly controlled by the ECU while the intermittent braking pressure is applied to the wheel cylinder 23, through which a stable braking is achieved.

On the other hand, regardless of the driver operating the brake pedal 22, the brake traction control system is activated when the slip phenomenon of the vehicle wheel is detected by the dispatch foot of the vehicle. At this time, the solenoid valve 30 for TC and the NC solenoid valve 25 are kept closed by the control of the ECU, and the braking pressure is applied to the wheel through the NO type solenoid valve 24 while the hydraulic pump 26 is driven. All. In addition, the oil is supplied to the hydraulic pump 26 through the reciprocating hydraulic valve 29 at the outlet side of the master cylinder 20, the hydraulic pump 26 is pressurized to make the brake of the wheel.

When the braking pressure at the outlet side of the hydraulic pump 26 is too high and the braking force applied to the wheel side is too large in the course of this operation, the flow path of the solenoid valve 30 for TC is closed by the pressure at the outlet side of the hydraulic pump 26. As it opens, the oil at the outlet of the hydraulic pump 26 flows toward the master cylinder 20. Therefore, the braking pressure applied to the wheels is properly maintained to prevent the wheels from completely stopping, thereby smoothly starting the vehicle.

This will be described in more detail with reference to FIG. 3. When power is applied to the excitation coil 34 of the TC solenoid valve 30 and the armature 33 moves forward toward the valve core 31, the plunger elastically supported through the safety spring 39 inside the armature 33 35 advances toward the valve seat 36 and closes the flow path of the valve seat 36. That is, the flow path of the TC solenoid valve 30 is closed.

In this state, if the pressure of the fluid applied to the inlet 31a of the valve core 31 becomes too high, the pressure of the fluid pushes the sphere 35a of the plunger 35 to open the flow path. At this time, the safety spring 39 inside the armature 33 is slightly compressed by the plunger 35 is pushed back by the hydraulic pressure. That is, the flow path is opened while the plunger 35 and the safety spring 39 are pushed out by the hydraulic pressure of the inlet 31a, thereby preventing excessive rise of the pressure at the outlet side of the hydraulic pump 26.

As described in detail above, the solenoid valve for the brake traction control system according to the present invention, when the pressure of the outlet side of the hydraulic pump is more than a predetermined pressure, the flow path is opened while the plunger is retracted by the pressure of the fluid and the oil on the hydraulic pump outlet side Since it can flow to the cylinder, there is an effect of properly adjusting the braking pressure at the outlet side of the hydraulic pump without a separate bypass passage and a pressure control valve. This also simplifies the configuration of the brake system and reduces the volume of the device.

Claims (4)

A valve core having a longitudinal through-hole formed at the center thereof and having an inlet and an outlet for fluid flow therein; an armature removably installed in the valve dome coupled to one end of the valve core; When the excitation coil is installed outside the valve dome, the plunger is installed in the through hole of the valve core so as to open and close the inlet of the valve core in conjunction with the movement of the armature, and when the power is not applied to the excitation coil. A solenoid valve for a brake traction control system having a restoring spring for returning the plunger and the armature to open the inlet of the valve core. A shaft hole formed longitudinally in the armature so that the plunger enters and retracts therein, a safety spring coupled to the outside of the plunger in the shaft hole and pressing the plunger toward an inlet of the valve core; The first support jaw integrally provided on the inner surface of the shaft hole of the arm to support the first end, the second support jaw formed on the outer surface of the plunger so that the end of the safety spring is supported, and the first support jaw formed through And a fixing member coupled to the outer surface of the plunger such that one end of the plunger is supported by being caught by the first supporting jaw. The method of claim 1, The solenoid valve for the brake traction control system, characterized in that the elasticity of the safety spring is larger than the elasticity of the restoring spring. The method of claim 1, Solenoid valve for brake traction control system, characterized in that the coupling groove of a predetermined depth is formed on the outer surface of the plunger to which the fixing member is coupled so that the fixing member is fitted. The method of claim 3, The fixing member is a solenoid valve for a brake traction control system, characterized in that the inner ring is a snap ring.

Images