KR100413256B1 - 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. Particularly, when excessive braking hydraulic pressure is applied to the wheels by the operation of a hydraulic hydraulic pump, the brake opening is opened so that the braking pressure drops by opening the valve by itself. A solenoid valve for a control system.

The solenoid valve for the brake traction control system according to the present invention has a shaft hole formed in the longitudinal direction in the interior of the armature so that one end of the plunger installed in the valve core can move forward and backward in the amateur, and one end of the plunger installed in the shaft hole. It has a safety spring for supporting the elastic spring, a fixing member installed inside the shaft hole to support the safety spring, and a fixing ring fixed to one end of the armature so that one end of the plunger entered into the shaft hole is supported, the inlet of the valve core When the side fluid pressure is high to overcome the elasticity of the safety spring, the plunger is pushed by the fluid pressure to open the valve flow path.

Description

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

The present invention relates to a brake traction control system that prevents road slippage of a vehicle wheel. More particularly, when an excessive braking hydraulic pressure is applied to a wheel side by an operation of a hydraulic pump, the opening of the valve opens by itself so that the braking pressure may drop. The present invention relates to a solenoid valve for a brake traction control system.

Recently, an anti-lock brake system (ANTI-LOCK BRAKE SYSTEM, hereinafter referred to as 'ABS') that prevents slipping of the wheel by periodically regulating the braking hydraulic pressure transmitted to the wheel side among hydraulic brake devices installed in a vehicle. There is).

As shown in FIG. 1, the vehicle ABS includes a NO (Normal 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, the ABS is provided with a hydraulic pump 5 for re-pressurizing the oil returning from the wheel side to generate a braking force, and a low pressure accumulator 6 and a high pressure accumulator 7 are provided on the upstream and downstream sides of the hydraulic pump 5. . And these devices are controlled by the ECU (not shown), the ECU controls the opening and closing of the NO and NC solenoid valves (3, 4) to control the braking hydraulic pressure supplied to the wheel side at the same time By controlling the driving of the hydraulic pump 5 to re-pressurize the fluid returned along the hydraulic line to the wheel side to make an intermittent braking.

In addition, such a vehicle ABS has a brake traction control system (BTCS) to prevent the wheels and road surface slip phenomenon at the start of the vehicle so that the vehicle can start smoothly.

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

The traction control system configured as described above operates the NO type solenoid valve 3 while the hydraulic pump 5 is driven by ECU control when slippage of the vehicle wheel is detected regardless of the driver's brake pedal 1a operation. The brake pressure is applied to the wheel cylinder 2 on the wheel side. At this time, since the TC solenoid valve 9 and the NC solenoid valve 4 remain closed, the oil supplied to the hydraulic pump 5 is reciprocated hydraulic valve 8 at the outlet side of the master cylinder 1. Supplied to the hydraulic pump (5) through, the hydraulic pump (5) to prevent the road slip phenomenon by pressing the brake to be made. In addition, at this time, when the braking hydraulic pressure of the outlet side of the hydraulic pump 5 is too high, the pressure regulating valve 10 is opened so that the oil is diverted through the bypass passage 10a, so that the braking hydraulic pressure applied to the wheel side is always maintained in an appropriate state. .

However, the conventional traction control system configured as described above should have a separate bypass passage 10a in order to prevent the pressure on the outlet side of the hydraulic pump 5 from being excessively increased, and the bypass passage 10 has a hydraulic pump 5. Since a separate pressure control valve 10 for detecting the pressure at the outlet side to be opened must be provided, not only the configuration of the brake system is complicated but also the volume of the device is large.

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

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

2 is a hydraulic circuit diagram of an anti-lock brake system to which a solenoid valve for a brake 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.

Figure 4 is a perspective view showing the configuration of a fixing ring according to the present invention.

5 is a perspective 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, 34: female coil,

35: plunger, 36: valve seat,

37: return spring, 38: retaining ring,

39: safety spring, 40: fixing member.

Solenoid valve for brake traction control system according to the present invention for achieving the above object is a valve core formed with a through hole in the longitudinal direction in the center and the inlet and outlet for fluid flow on one side, and one end of the valve core An armature removably installed inside the valve dome to seal the valve, an excitation coil installed on the outside of the valve dome to advance the armature, and an opening and closing of the valve core in conjunction with the armature movement of the armature. A solenoid valve for a brake traction control system having a plunger removably installed inside the through hole of the core and a return spring which opens the inlet of the valve core by returning the plunger and the amateur when no power is applied to the excitation coil. Wherein one end of the plunger is inside the amateur A shaft hole formed in the amateur to enter and retreat to the entrance, a safety spring installed inside the shaft hole to elastically support one end of the plunger, a fixing member installed inside the shaft hole to support the safety spring, and the shaft hole. And a fixing ring fixed to one end of the armature so that one end of the plunger entered is supported, and the elasticity of the safety spring is greater than the elasticity of the return spring.

In addition, one end of the plunger entered into the shaft hole is provided with a guide portion constituting the jaw coinciding with the inner diameter of the shaft hole, characterized in that the guide portion is supported by being caught by the fixing ring.

In addition, the outer surface of the fixing member is provided with a plane to form a flow path between the inner surface of the shaft hole to facilitate the retreat of the plunger entered into the shaft hole, one side is cut off in the fixing ring to form an opening to form the flow path Characterized in that provided.

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

In the vehicle ABS to which the present invention is applied, as shown in FIG. 2, a NO (Normal Open) type solenoid installed in the middle of a hydraulic line connected from the master cylinder 20 to the wheel-side wheel cylinder 23 to open and close the supply flow path. The valve 24 is provided, and the NC (Normal Close) solenoid valve 25 which opens and closes the flow path of the fluid returned from the wheel side is provided. At this time, when the NO type solenoid valve 24 is open, the NC type solenoid valve 25 is closed to apply braking pressure to the wheel side, and when the NO type solenoid valve 24 is closed, the NC type solenoid valve 25 is closed. Open to release the brake pressure.

In addition, the ABS includes a hydraulic pump 26 for repressurizing oil returned from the wheel-side wheel cylinder 23 to an upstream side of the NO-type solenoid valve 24, and a buffer space (upper and downstream of the hydraulic pump 26) is provided. The low pressure accumulator 27 and the high pressure accumulator 28 which comprise 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 side, and the downstream side of the hydraulic pump 26. The high-pressure accumulator 28 installed in the function serves to attenuate the pressure pulsation according to the operation of the hydraulic pump 26 while the oil pressurized in the hydraulic pump 26 is temporarily stored. 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 to open and close the flow path supplied to the wheel side, and also controls the driving of the hydraulic pump 26 to the low pressure accumulator 27 through the return flow path. The returned fluid is re-pressurized to the wheel side so that intermittent braking is achieved.

In addition, such a vehicle ABS is provided with a brake traction control system (BTCS) to prevent the wheels and road surface slip phenomenon at the start of the vehicle to smoothly start the vehicle.

The brake traction control system includes a separate hydraulic line 29a for connecting the outlet side hydraulic line of the master cylinder 20 and the inlet side hydraulic line of the hydraulic pump 26. In addition, the hydraulic line 29a is provided with a reciprocating hydraulic valve 29 which closes the flow path when the driver presses the brake pedal 22 and maintains a state of being normally opened. This is to ensure that the braking hydraulic pressure is transmitted only to the wheel side when the driver normally presses 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, but the oil passage is closed when the road surface slip of the wheel occurs due to sudden departure of the vehicle. The solenoid valve 30 for TC is provided so that the braking pressure generated by the driving of the pump 26 can be transmitted to the wheel side. In this case, the solenoid valve for TC 30 according to the present invention is characterized in that the opening of the valve is opened when the pressure of the outlet side flow path of the hydraulic pump 26 is greater than or equal to the predetermined pressure so that a part of the oil can flow toward the master cylinder 20. .

Referring to FIG. 3, the TC solenoid valve 30 has a longitudinal through hole 31c formed at the center thereof, and a magnetic inlet 31a and outlet 31b for introducing and discharging oil at a lower end thereof. The valve core 31 is provided. And the upper end of the valve core 31 is covered with a valve dome 32 provided in a thin cylindrical shape is coupled. In addition, the inside of the valve dome 32 is provided with a cylindrical armature 33 is formed with a shaft hole 33a in the center, the armature 33 is installed so that the predetermined section can be moved in the longitudinal direction. And a portion of the valve core 31 and the outer surface of the valve dome 32 is covered with a cylindrical excitation coil 34 for advancing and retracting the armature 33 is coupled to the coupling.

A rod-shaped plunger 35 capable of advancing and retracting in the longitudinal direction is provided in the valve core 31 through-hole 31c. At this time, the plunger 35 is disposed so that one end thereof is adjacent to the valve seat 36 installed at the inlet 31a of the valve core 31, and the other end thereof is in a state of entering the shaft hole 33a of the armature 33. do. At this time, the sphere 35a blocking the flow of oil by blocking the flow path of the valve seat 36 when the plunger 35 is advanced by the operation of the armature 33 at the end of the plunger 35 adjacent to the valve seat 36. Is coupled to the outer surface of the plunger 35 adjacent to the sphere 35a, the first guide portion 35b having an outer diameter coinciding with the inner diameter of the through hole 31c and forming a jaw to guide the retreat of the plunger 35 is provided. Prepared. In addition, at the end of the plunger 35 adjacent to the valve seat 36, a return spring 37 for retracting the plunger 35 and the armature 33 to open the flow path when power is not applied to the excitation coil 34 is provided. Is installed. The return spring 37 is supported by the first guide portion 35b with one end supported by the valve seat 36 and the other end partially fitted to the end of the plunger 35.

On the other hand, the other end of the plunger 35 entered into the shaft hole 33a of the armature 33 is provided with a second guide portion 35c whose outer diameter coincides with the inner diameter of the shaft hole 33a and forms a jaw. The guide portion 35c is configured to advance and retreat a predetermined section inside the amateur 33. At this time, a fixing ring 38 is installed at one end of the armature 33 adjacent to the valve core 31 so that the second guide part 35c of the plunger 35 is caught and supported at the end of the armature 33. A fixing groove 33b for fixing 38 is formed. In addition, a safety spring 39 for elastically supporting the end of the plunger 35 and a fixing member 40 for supporting the safety spring 39 are installed in the shaft hole 33a. That is, the safety spring 39 is supported by the fixing member 40, one end of which is supported by the end of the plunger 35 and the other end of which is press-fitted so that the second guide part 35c is in close contact with the fixing ring 38. Keep your status.

At this time, the elasticity of the safety spring (39) is greater than the elasticity of the return spring (37) installed on the valve seat 36 side when the armature 33 is operated, the safety spring (39) wins the elasticity of the return spring (37) It should be possible 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 allow fluid to flow into the gap between the valve seat 36 and the sphere 35a. This allows the fluid pressure at the outlet of the hydraulic pump 26 to be determined by the elasticity of the safety spring 39.

In addition, as shown in FIG. 4, the fixing ring 38 fixed to the armature 33 is provided with an opening part 38a in a state of being disconnected at one side, and when the fixing part 38a is fixed to the armature 33, the opening part 38a is a flow path. To form. In addition, the fixing member 40 fixed to the inside of the shaft hole 33a to support the safety spring 39, as shown in Figure 5, the outer surface is provided with a plane (40a) and the inner surface of the shaft hole (33a) A flow path is formed between them. This configuration allows the second guide part 35c of the plunger 35 to easily retreat while the safety spring 39 inside the shaft hole 33a is compressed.

The following describes the operation of the vehicle ABS to which the solenoid valve for TC configured as described above is applied.

When the driver presses the brake pedal 22, the back pressure is generated by the pressure difference in the power supply device 21, the master cylinder 20 receives the amplified force to form a braking hydraulic pressure, 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. The slip phenomenon is detected through 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 20 to escape, thereby releasing the temporary braking to prevent slippage.

In addition, the oil discharged through the NC-type solenoid valve 25 is moved to the low pressure accumulator 27 and stored for a while, the oil of the low pressure accumulator 27 is re-pressurized by the driving of the hydraulic pump 26, the high pressure accumulator ( 28) discharged to the inside, 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 causes the wheel cylinder 23 to apply an intermittent braking pressure while being repeatedly controlled by the ECU.

On the other hand, regardless of the driver operating the brake pedal 22, the brake traction control system is activated when a slip phenomenon of the wheel of the vehicle is sensed by sudden start of the vehicle or the like. At this time, the TC solenoid valve 30 and the NC solenoid valve 25 are kept closed by the control of the ECU, and the hydraulic pump 26 is driven to apply braking hydraulic pressure to the wheel side through the NO type solenoid valve 24. do. 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, and the hydraulic pump 26 pressurizes it so that the brake of the wheel is made to perform slippage of the wheel. prevent.

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

Referring to FIG. 3, this operation will be described in more detail. When power is applied to the excitation coil 34 of the TC solenoid valve 30, the armature 33 moves forward toward the valve core 31, and the armature 33 is inside the armature 33. The plunger 35, which is elastically supported by the safety spring 39, advances toward the valve seat 36 to block 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 excessively 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 amateur 33 is slightly compressed by the plunger 35 that 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 by the hydraulic pressure of the inlet 31a, thereby preventing the excessive rise of the pressure of the outlet side of the hydraulic pump 26.

As described in detail above, in the solenoid valve for the brake traction control system according to the present invention, when the outlet side pressure of the hydraulic pump is greater than or equal to the predetermined pressure, the flow path is opened while the plunger is retracted by the pressure of the fluid, thereby opening the hydraulic pump outlet side. By allowing oil to flow into the master cylinder, there is an effect of properly adjusting the braking pressure at the outlet side of the hydraulic pump without a separate bypass flow path and a pressure control valve. In addition, it is possible to simplify the configuration of the brake system to reduce the volume of the device, as well as to increase the manufacturability of the device.

Claims (4)

A valve core having a longitudinal through hole formed at a center thereof and an inlet and an outlet for fluid flow at one side thereof, an armature removably installed inside the valve dome sealing one end of the valve core, Power is applied to the excitation coil, an excitation coil installed outside the valve dome, a plunger installed in the through hole of the valve core so as to open and close the inlet of the valve core in association with the advance movement of the armature, and the excitation coil. A solenoid valve for a brake traction control system having a return spring for returning the plunger and the armature to open the inlet of the valve core when not in operation. A shaft hole formed in the armature so that one end of the plunger enters and exits the armature, a safety spring installed in the shaft hole to elastically support one end of the plunger, and an inside of the shaft hole to support the safety spring. A solenoid valve for a brake traction control system including an installed fixing member and a fixing ring fixed to one end of the armature so that one end of the plunger entering the shaft hole is supported. 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 return spring. The method of claim 1, One end of the plunger entering the shaft hole is provided with a guide portion constituting the jaw coinciding with the inner diameter of the shaft hole, the guide portion is a solenoid valve for the brake traction control system, characterized in that supported by the holding ring. The method of claim 1, The outer surface of the fixing member is provided with a plane to form a flow path between the inner surface of the shaft hole to facilitate the retreat of the plunger entered into the shaft hole, the fixing ring is provided with an opening portion for disconnecting one side to form a flow path. A solenoid valve for a brake traction control system, characterized in that.