KR20020067842A - Hydraulic shuttle valve of brake traction control system - Google Patents

Abstract

PURPOSE: A reciprocating type-hydraulic valve of a brake traction control system is provided to prevent oil flowed into a valve core from being discharged outside by combining a sealing member without a special sealing device. CONSTITUTION: A reciprocating type-hydraulic valve of a brake traction control system is equipped with a valve core(110) having an orifice(111) formed within, a piston(120) moving up and down, a valve member(121) opening and shutting the orifice according to the movement of the piston, a sealing member(130) sealing the lower end of the valve core and simultaneously housing the lower end, to be moved up and down, and an upper and lower springs, disposed to the upper and lower part of the piston, working elastic force of mutual opposite direction on the piston. The sealing member comprises a housing(131) having open upper part to fit the lower end of the piston and an elastic material(132) to be filled in the housing. The lower end of the piston is supported by contraction and expansion of the elastic material to be able to move up and down. Therefore, sealing between the piston and valve core is not required.

Description

Hydraulic shuttle valve of brake traction control system

The present invention relates to a reciprocating hydraulic valve used in a brake traction control system.

In general, the vehicle is equipped with a hydraulic brake for braking the front wheel and the rear wheel, a hydraulic power unit for forming and transmitting the braking hydraulic pressure to the hydraulic brake side, and a master cylinder, so that the braking hydraulic pressure is formed when the driver presses the brake pedal. To generate braking force. However, if the braking force is greater than the frictional force of the road when the driver steps on the brake pedal to increase / maintain the braking force, slippage of the tire may occur on the road surface.

In order to effectively prevent such slip phenomenon and to obtain a strong and stable braking force, the vehicle may be equipped with an anti-lock brake system, which controls the braking hydraulic pressure transmitted to the hydraulic brake side. And a plurality of solenoid valves, accumulators and pumps, ECUs for controlling the electric drive elements.

Recently, the anti-lock brake system (hereinafter referred to as ABS) can be used to increase the stability of the vehicle by preventing slip from occurring when starting the vehicle while stepping on an accelerated pedestal or driving a curved road at high speed. A braking system has been developed that additionally incorporates a brake traction control system (BTCS).

The brake traction control system is composed of a separate hydraulic line connecting the brake hydraulic outlet line of the master cylinder and the inlet hydraulic line of the pump, and is equipped with a hydraulic suttle valve for opening and closing the hydraulic line. .

The reciprocating hydraulic valve is configured to remain open in a normal state and then close when the brake pedal is transmitted to the valve by the driver when the driver presses the brake pedal. On the other hand, if a slip occurs when the driver starts the vehicle or runs on a curve while stepping on the acceleration pedal, the reciprocating hydraulic valve is opened to transmit a slight braking hydraulic pressure to the hydraulic brake so that the slip does not occur. Do not

Figure 1 shows the internal structure of a conventional reciprocating hydraulic valve. As shown in the drawing, the conventional reciprocating hydraulic valve is formed in the modulator block 1 and includes a bore 2 having a suction port 2a and a discharge port 2b formed on a side thereof, and inside the bore 2. The piston 4 is fixed and is installed so as to move up and down in the valve core 3, the orifice (3a) is formed, and the valve member 5 of the rubber material on the upper portion of the valve core (3) ), A housing cap 6 inserted into the lower portion of the valve core 3 and having a vent 6a formed therein, which communicates with the outside in the longitudinal direction, and a suction port 2a coupled to the upper end of the valve core 3. Is provided with a filter (8) in communication with.

The valve member 5 is located upstream of the orifice 3a to open or close the orifice 3a in accordance with the shanghai movement of the piston 4, and the top of the piston 4 for the shanghai movement of the piston 4. An upper spring 9 is installed between the inner ends of the filter 8, and a lower spring 10 is installed between the lower part of the piston 4 and the inner end of the housing cap 6. In the normal state, the elastic force of the lower spring 10 is set to be greater than the elastic force of the upper spring 9 in order to keep the valve member 5 spaced apart from the orifice 3a.

In order to prevent oil passing through the orifice 3a from flowing out through the gap between the piston 4 and the valve core 3 and the gap between the bore 2 and the valve core 3, the piston 4 Seals 11a and 11b are attached to the bottom of the valve core and the bottom of the valve core 3, respectively.

In addition, a damping rubber 7 is attached to the inner end of the housing cap 6 in order to reduce the noise generated when the lower end of the piston 4 hits the housing cap 6 during downward movement of the piston 4.

The piston 4 of the conventional reciprocating hydraulic valve is pushed upward by the lower spring 10 having a greater elastic force than the elastic force of the upper spring 9 in a normal state, that is, the hydraulic pressure is not applied to the valve. The valve member 5 is spaced apart from the orifice 3a so that the valve is kept open.

Therefore, the suction port 2a and the discharge port 2b communicate with each other through the orifice 3a formed in the valve core 3, so that the oil flows due to the driving of the pump (not shown) without stepping on the brake pedal (not shown). The master cylinder (not shown) side and the pump inlet side (not shown) are linked to form an oil supply passage.

When the driver presses the brake pedal, a part of the braking pressure oil flows into the bore 2 through the suction port 2a. When the oil pressure exceeds a predetermined value, the hydraulic pressure and the elastic force of the upper spring 9 become lower spring. The piston 4 moves downward while winning the elastic force of 10. Therefore, the valve member 5 comes into close contact with the orifice 3a, whereby communication between the suction port 2a and the discharge port 2b is interrupted.

On the other hand, the air filled in the space formed between the lower end of the piston 4 and the housing cap 6 during the downward movement of the piston 4 flows out through the vent 6a of the housing cap 6 to the outside of the piston 4. Ensure downward movement is smooth.

However, in the conventional reciprocating hydraulic valve, a seal attached to the outer circumference of the piston causes an obstacle in the vertical movement of the piston to prevent oil from flowing out through the gap between the piston and the valve core. In other words, the seal attached to the outer periphery of the piston is strongly adhered to the valve core in order to prevent oil from leaking out. Therefore, in the low pressure mode of ABS, the piston does not move smoothly due to the friction force between the seal and the valve core. It will limit the implementation of the.

In addition, in the conventional reciprocating hydraulic valve, since the seal is inevitably worn out by a long-term repetitive operation, there is a possibility that oil may leak through the gap between the piston and the valve core.

In addition, the conventional reciprocating hydraulic valve has a disadvantage in that the structure and the manufacturing cost and manufacturing time is increased because the damping lever and the housing in which the vent is formed must be essentially provided for moving the piston.

The present invention is to solve this problem, an object of the present invention is to combine the sealing member that can support the piston in one end of the valve core so that the oil flowing into the valve core without a separate sealing means It is to provide a reciprocating hydraulic valve of a brake traction control system that can prevent leakage to the air.

Another object of the present invention is to provide a reciprocating hydraulic valve of a brake traction control system capable of quickly and smoothly opening and closing a valve by installing a piston without contacting the inside of the valve core.

1 is a cross-sectional view showing the internal structure of a conventional reciprocating hydraulic valve.

2 is a hydraulic system diagram of a brake traction control system to which the present invention is applied.

3 is a cross-sectional view showing the internal configuration of the reciprocating hydraulic valve according to the present invention in the brake traction control state.

Figure 4 is a cross-sectional view showing the internal configuration of the reciprocating hydraulic valve according to the present invention in the normal braking state.

* Description of symbols on the main parts of the drawings *

100. Reciprocating hydraulic valve 110. Valve core

120 pistons 121 valve elements

130. Airtight 131 Housing

132. Elastic materials

The reciprocating hydraulic valve of the brake traction control system according to the present invention for achieving this object, a valve core having an orifice formed therein, a piston installed so as to be movable in the valve core, and the outer peripheral edge of the piston A valve member installed in the valve member for opening and closing the orifice in accordance with the shanghai movement of the piston, a sealing member sealing the lower end of the valve core and allowing the lower end of the piston to be movable; It is characterized in that the upper and lower springs disposed on the lower portion to apply elastic forces in opposite directions to each other.

The sealing member is composed of a housing having an upper portion open so that the lower end of the piston is fitted, and an elastic material filled in the housing, so that the lower end of the piston is damaged by the contraction and expansion of the elastic material in the housing. Copper is possibly supported.

Preferably, the elastic material is made of an elastomer (elastomer).

Preferably, the housing has an upper end fitted inside the valve core, and a lower end thereof is cocked and fixed to an outer end of the valve core.

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

Brake Traction Control System (BTCS) is a slippery road surface that is slippery when the vehicle starts or runs.As a result, the pump of ABS drives a predetermined braking force on the wheel side without the driver stepping on the brake pedal. By doing so, the driving of the vehicle is made safe.

As shown in FIG. 2, the brake traction control system that performs this function includes the hydraulic outlet side of the master cylinder 12 and the pump 42 together with the ABS hydraulic circuit having a plurality of solenoid valves 30 and 31. A separate hydraulic line 50 connecting the inlet side, a reciprocating hydraulic valve 100 installed on the hydraulic line 50 to control communication thereof, the hydraulic outlet side of the master cylinder 12 and the high pressure accumulator TC solenoid valve 70 is provided in the hydraulic line 51 connecting the outlet side of the radar 43.

The solenoid valve of the ABS hydraulic circuit is connected to the upstream side of the hydraulic brake 20 and is normally open solenoid valve (30; hereinafter referred to as NO type solenoid valve) which is normally kept open, and is normally connected to the downstream side and normally closed. And a normal closed solenoid valve 31 (hereinafter referred to as an NC solenoid valve) that is held in a closed state. The opening and closing operation of the solenoid valves 30 and 31 is controlled by an ECU (not shown), which operates based on a signal input from a wheel sensor (not shown).

In the discharge line of the NC-type solenoid valve 31, a low pressure accumulator 40 in which pressure oil passing through the hydraulic brake 20 is temporarily stored, and oil stored in the low pressure accumulator 40 are disposed at a rear side thereof. A pump 42 for pumping pressure by the high pressure accumulator 43 is disposed.

On the other hand, the TC solenoid valve 70 is installed in the hydraulic line 51 connecting the outlet side of the high-pressure accumulator 43 and the outlet side of the master cylinder 12, which is normally open and is normally open. After the vehicle slip is detected, the vehicle is closed by the ECU (not shown).

In addition, as described above, there is provided a separate hydraulic line 50 directly connecting the outlet side of the master cylinder 12 and the inlet side of the pump 42, the reciprocating hydraulic valve 100 is installed in this line do. The reciprocating hydraulic valve 100 is maintained in an open state in a normal state and then closed when the driver steps on the brake pedal 13 and a brake hydraulic pressure of 2 bar or more is transmitted to the inside thereof, thereby closing the pump 42 to the pump 42 side. To shut off the oil supply channel.

3 shows a state in which the reciprocating hydraulic valve 100 performing such a function is normally opened.

The reciprocating hydraulic valve 100 according to the present invention is installed in the bore 102 formed to have a predetermined depth in the modulator block 101 and the valve core 110 and the valve core 110 is formed therein, the valve core Piston 120 is disposed on the 110 and the outer periphery of the piston 120, the valve member 121 for opening and closing the orifice 111 and the lower end of the valve core 110 is provided It is provided with a sealing member 130 for receiving the lower end of the piston 120 to be movable.

The modulator block 101 has a suction port 103 for communicating the outlet side of the master cylinder 12 (see FIG. 2) with the lower portion of the bore 102, and the inlet side of the pump 42 (see FIG. 2). A discharge port 104 is drilled for communicating the intermediate portion of the bore 102.

The valve core 110 is fitted into the bore 102 and is fixed, and an inlet 112 is provided at an upper portion corresponding to the suction port 103, and an outlet 113 is formed at a side surface corresponding to the discharge port 104. An orifice 111 is formed between them. The valve core 110 is fitted into the bore 102 and is fixed through the clutching means. When the fixing operation is completed, the inlet 112 is in direct communication with the suction port 103, and the outlet 113 is discharge port 104. Direct communication with). A filter 114 is installed at an upper end of the valve core 110 to filter the oil flowing into the valve 100.

The sealing member 130 is a housing 131 that is open at the top and is fitted to the lower end of the valve core 110 to seal the valve core 110, and an elastic material 132 that is filled in the inner space of the housing 131. It is composed. The elastic material 132 is made of a bulky elastic elastomer to allow the piston 120 to be movable. The upper end of the housing 131 of the sealing member 130 is fitted inside the valve core 110, and the lower end of the housing 131 is cocked and fixed to the outer end of the bore 102. Here, the housing 131 may be fixed to the outer end of the valve core 110 is cocked.

The piston 120 is disposed in the longitudinal direction inside the valve core 110, the valve member 121 is made of an elastic material such as rubber to the outer periphery of the upper end of the piston 120 located upstream of the orifice 111 Is fixed to. The lower end of the piston 120 is fitted to the housing 131 of the sealing member 130 is supported by the elastic material 132 so as to be movable. Therefore, the piston 120 is installed to be spaced apart from the inner circumferential surface of the valve core 110 in a predetermined space in the inner space of the valve core 110 to be moved.

An upper spring 140 is installed between the upper end of the piston 120 and the inner end of the filter 114 to push the piston 120 in the direction of closing the orifice 111, and seals the lower end of the piston 120. A lower spring 150 is installed between the housings 131 of the member 130 to push the piston 120 in the direction of opening the orifice 111. A retainer 151 is disposed at an upper end of the lower spring 150 to smoothly expand and contract the lower spring 150.

In order to keep the reciprocating hydraulic valve 100 open in the normal state, the elastic force of the lower spring 150 is set greater than the elastic force of the upper spring 140. That is, when the braking hydraulic pressure is not transmitted to the inside of the inlet 112, the valve member 121 is spaced apart from the orifice 111 by the elastic force of the lower spring 150 designed to be larger than the elastic force of the upper spring 140. Be sure to

Next, the operation and effects of the brake traction control system equipped with the reciprocating hydraulic valve 100 according to the present invention configured as described above will be described with reference to FIGS. 2 to 4.

First, when the driver presses the brake pedal 13 while the vehicle equipped with the brake traction control system is running, a braking hydraulic pressure is formed in the master cylinder 12, which is the hydraulic brake 20 through the NO solenoid valve 30. ) To brake.

At the same time, a part of the braking hydraulic pressure is also transmitted to the reciprocating hydraulic valve 100 side through the suction port 103. When a pressure of 2 bar or more is transmitted to the inlet 112 side, as shown in FIG. 4, the upper spring 140 As the lower spring 150 is compressed by the elastic force and hydraulic pressure of the piston 120, the piston 120 moves downward by a predetermined distance in the downward direction of the valve core 110. At the same time, the valve member 121 also moves downward with the piston 120 to block the orifice 111. Accordingly, the communication between the inlet 112 and the outlet 113 is blocked, so that the braking pressure oil is transmitted only to the hydraulic brake 20 side.

At this time, the elastic material 132 filled in the housing 131 can be reduced in volume by the action of a small force, the lower end of the piston 120 in the housing 131 of the sealing member 130 132 is pressed to smoothly move downward while reducing its volume.

And if the ECU (not shown) detects the wheel lock (WHEEL LOCK) by the electrical signal input from the wheel sensor (not shown) and ABS control is required, the NO type solenoid valve 30 and the NC type solenoid valve (31). ) To reduce the brake hydraulic pressure. That is, the NC type solenoid valve 31 is opened to partially escape the braking hydraulic pressure, which is temporarily stored in the low pressure accumulator 40. When the braking hydraulic pressure of the hydraulic brake 20 is reduced or increased to an optimal state, the ECU (not shown) operates the NO type solenoid valve 30 to maintain the braking hydraulic pressure of the hydraulic brake 20 as it is. At this time, the drive current to the NC solenoid valve 31 side does not flow, so that the flow path of the low pressure accumulator 40 is blocked.

In addition, when the pressure boosting of the hydraulic brake 20 is required, the ECU (not shown) interrupts the current supply of the NO solenoid valve 30 and simultaneously drives the motor 41 to brake according to the operation of the pump 42. Hydraulic pressure is generated which causes the hydraulic brake 20 to actuate the hydraulic pressure.

When the driver releases the brake pedal 13, the solenoid valves 30 and 31 are in an initial state, and since the braking hydraulic pressure is not transmitted to the reciprocating hydraulic valve 100, the elasticity of the lower spring 150 may be reduced. The piston 120 moves upward by the restoring force, and the inlet 112 and the outlet 113 are restored to the communication state. At this time, the elastic material 132 filled in the housing 131 is expanded again to its original form.

On the other hand, if the driver makes a quick start on the slippery road condition, a momentary speed difference occurs between the vehicle speed and the wheel speed, which is detected by the ECU through the wheel sensor. That is, when the road surface is frozen or when slipping occurs by stepping on the acceleration pedal when the vehicle starts on a gravel road or the like, such a situation is detected by the ECU through a wheel sensor and the motor 41 is immediately driven.

Accordingly, the oil is pressurized and pumped according to the pumping operation of the pump 42, and is delivered to the hydraulic brake 20 through the high pressure accumulator 43 and the NO solenoid valve 30 to act as a braking hydraulic pressure. As a result, when the driver starts the vehicle while depressing the accelerator pedal, the wheel is locked even when the driver does not press the brake pedal 13, so that the vehicle starts slowly and safely.

In addition, by applying power to a separate TC solenoid valve 70 provided in a hydraulic line connecting the high pressure accumulator 43 and the master cylinder 12, the oil pressure by the operation of the pump 42 is All are delivered to the hydraulic brake 20 side. In addition, since the inlet 112 and the outlet 113 of the reciprocating hydraulic valve 100 according to the present invention are kept in communication with each other when the brake pedal 13 is not stepped on, as shown in FIG. 3. The oil supply is smoothly supplied to the pump 42 through the hydraulic line 50 connecting the outlet side of the master cylinder 12 and the inlet side of the pump 42.

In the above description, the operation of the brake traction control system has been described using only an example of when the vehicle starts, and the same operation is performed even when driving on a gravel road or a muddy road while stepping on an accelerator pedal or when slip occurs on a wheel on a curve road. At this time, the oil supply to the pump 42 side during the operation of the brake traction control system is smoothly because the reciprocating hydraulic valve 100 according to the present invention is kept open. That is, since the lower spring 150 elastically supports the valve member 121 installed in the piston 120 in the upward direction, the inlet 112 is applied except that the braking hydraulic pressure is transmitted through the suction port 103. And the outlet 113 are in communication with each other to form an oil supply passage to the pump 42 side.

As described in detail above, according to the reciprocating hydraulic valve of the brake traction control system according to the present invention, the piston which opens and closes the orifice by moving in and out of the valve core is installed to be spaced apart from the inner peripheral surface of the valve core at a predetermined interval. Since it operates without contacting the core, the piston can be moved smoothly.

In addition, since the sealing member is installed at the lower end of the valve core and the elastic material is filled in the sealing member so as to be elastic, the lower end of the piston is supported to be movable. Therefore, there is no need to seal between the piston and the valve core. . In addition, the sealing member is simply cocked and fixed, thereby simplifying the assembly work and simplifying the structure of the valve.

Claims (6)

A valve core 110 having an orifice 111 formed therein, a piston 120 installed so as to be movable in the valve core 110, and an outer circumference of the piston 120, the piston ( The valve member 121 which opens and closes the orifice 111 and the lower end of the valve core 110 according to the shanghai movement of 120 and at the same time seals the lower end of the piston 120 so as to be movable. And a member 130 and upper and lower springs 140 and 150 disposed on upper and lower portions of the piston 120 to apply elastic forces in opposite directions to the piston 120, respectively. Reciprocating hydraulic valve of brake traction control system. The method of claim 1, The sealing member 130 is composed of a housing 131, the top of which is open so that the lower end of the piston 120 is fitted, and an elastic material 132 filled in the housing 131, The lower end of the piston (120) is a reciprocating hydraulic valve of the brake traction control system, characterized in that the movable movement is supported by the contraction and expansion of the elastic material (132) inside the housing (131). The method of claim 2, The elastic material 132 is a reciprocating hydraulic valve of the brake traction control system, characterized in that consisting of an elastomer (elastomer). The method of claim 2, The housing 131 has an upper end thereof fitted into the valve core 110, and a lower end thereof is fixed to the outer end of the valve core 110 by being caulked to fix the reciprocating hydraulic pressure of the brake traction control system. valve. The method of claim 2, The lower spring 150 is a reciprocating hydraulic valve of the brake traction control system, characterized in that disposed between the outer circumference of the piston 120 and the outer circumference of the housing (131). The method of claim 5, A reciprocating hydraulic valve of a brake traction control system, characterized in that a retainer (151) is installed between the upper end of the lower spring (150) and the outer circumference of the piston (120).