KR200267460Y1 - Damping apparatus of anti-lock brake system for car - Google Patents

Abstract

The present invention relates to an antilock brake system for a vehicle, and its purpose is to efficiently attenuate the regular pressure pulsation generated by the pump drive.

The damping device of the vehicle anti-lock brake system according to the present invention is provided with a separate auxiliary damper (70) in parallel with the high-pressure accumulator (60) provided with an orifice (61) on the outlet end side of the pump (51). Therefore, the regular pressure pulsation generated by driving the pump 51 is completely attenuated by the high pressure accumulator 60 and the auxiliary damper 70, thereby reducing the overall operating noise and controlling the reliability of the product. have.

Description

Damping apparatus of anti-lock brake system for car

The present invention relates to a vehicle anti-lock brake system, and more particularly, to a damper device for reducing pressure pulsations periodically generated by a pair of pumps driven while having a phase difference of 180 degrees.

The brake device for braking is indispensable to the vehicle, and in recent years, various kinds of systems for obtaining a more powerful and stable braking force have been proposed. Among them, the anti-lock brake system has a progressive effect. FIG. 1 is a hydraulic system diagram showing a general configuration of such an anti-lock brake system.

Conventional vehicle anti-lock brake system, as shown here, solenoid valve (3,4) and pump for controlling the braking hydraulic pressure transmission to the hydraulic brake (2) side provided on the front wheel (FL, FR) and the rear wheel (RL, RR) (7a, 7b) and the like are provided in a closed circuit through the hydraulic line, and are largely composed of the booster (1a) and the master cylinder (1b) and the like operated by the brake pedal (1).

The power booster 1a is a device that generates a large braking force with a small force by using a pressure difference between the vacuum and the atmosphere, and is operated by the brake pedal 1 provided in the driver's seat. The master cylinder 1b forms a braking hydraulic pressure by receiving the amplified force from the power booster 1a, and is connected to the hydraulic brake 2 through a hydraulic line.

On the other hand, solenoid valves 3 and 4 are installed in the hydraulic supply lines of the hydraulic brakes 2 to control the braking hydraulic pressure generated from the master cylinder 1b, which is a normally open solenoid valve 3 disposed at the inlet side end. ) And a normal closed solenoid valve 4 disposed at an outlet side end, and are controlled by an ECU (not shown) to exhibit a strong and stable braking force. At this time, the ECU detects the vehicle speed through wheel sensors (not shown) provided at the front wheels FR and FL and the rear wheels RR and RL, and based on the signals inputted from the solenoid valves 3 and 4. Control opening and closing.

In addition, a pair of low pressure accumulators 5a and 5b are provided downstream of the normal closed solenoid valve 4 on the front wheel FR and FL and the rear wheel RR and RL. The oil exiting from is temporarily stored. In addition, high-pressure accumulators 8a and 8b are also provided on the rear side of the low-pressure accumulators 5a and 5b, and a pair of pumps 7a and 7b are formed therebetween so that the low-pressure accumulators 6a and 6b are provided. The oil in the low pressure state temporarily stored in is pressurized and pumped to the high pressure accumulators 8a and 8b. At this time, since the pair of pumps 7a and 7b are operated by one drive motor 6, they pump with a phase difference of 180 degrees. Reference numeral 9 is an orifice provided on the outlet end side of the high pressure accumulators 8a and 8b to reduce pressure pulsation.

In the conventional anti-lock brake system configured as described above, when the driver presses the brake pedal 1 while driving, the back force is generated by the pressure difference in the power supply device 1a, and the master cylinder 1b receives the amplified force. To form hydraulic pressure. The braking hydraulic pressure is delivered to the respective hydraulic brakes 2 provided on the front wheels FR and FL and the rear wheels RR and RL through the normally open solenoid valve 3 to perform a braking action.

On the other hand, when excessive braking pressure is transmitted than the road condition, a kind of slip phenomenon occurs that the tire of the vehicle stops rotating and slips. When this phenomenon is detected through the wheel sensor mounted on the wheel side of the vehicle, the ECU is normally closed solenoid. Operate valve 4 to open. As a result, a part of the oil in the hydraulic brake 2 is released and the braking pressure is lowered, thereby preventing slippage and providing a safe braking action.

On the other hand, the oil discharged through the normal closed solenoid valve 4 is moved to the low pressure accumulators 5a and 5b and stored for a while, and when the driving motor 6 is driven by the braking pressure boost signal, the pump 7a, The pressure rises again through 7b) and passes through the high pressure accumulators 8a and 8b and the orifice 9 to circulate toward the master cylinder 1b or the normally open solenoid valve 3 in a state where the abrupt pressure waveform is reduced. .

However, such a conventional anti-lock brake system generates a sudden pressure pulsation due to the driving of a pair of pumps 7a and 7b during the braking pressure boosting process. That is, the pumps 7a and 7b have a 180 degree phase difference by one driving motor 6, so that the pumping action is performed, so that the pit of the semi-square wave is regularly generated at the outlet end of the pumps 7a and 7b. . This pumping pressure wave is attenuated by the oil being discharged through the orifice 9 provided on the discharge port side of the high pressure accumulators 8a and 8b.

However, the orifice 9 is made of a structure that exerts a damping effect by simply reducing the flow path area, and there is a limit in completely reducing the pressure pulsation.

Therefore, the pit of pressure pulsation is continuously generated during the pumping operation driven with a phase difference of 180 degrees, and this phenomenon acts as a source of operating noise of the anti-lock brake system, thereby reducing the overall product reliability.

The present invention is to solve this problem, an object of the present invention by installing a separate auxiliary damper in parallel with the high-pressure accumulator provided in the orifice at the outlet end side of the pump is oil pressure pumping, It is to provide a damping device for a vehicle anti-lock brake system which is a regular pressure pulsation and efficiently attenuated by a pressure accumulator and an auxiliary damper.

1 is a hydraulic system diagram schematically showing a conventional anti-lock brake system.

2 is a hydraulic system diagram of a vehicle anti-lock brake system according to the present invention.

3 is a cross-sectional view showing an auxiliary damper according to the present invention.

Figure 4 is a perspective view showing a damping piston structure of the auxiliary damper according to the present invention.

5 is a cross-sectional view showing an operating state of the auxiliary damper according to the present invention.

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

50. Drive motor 51. Pump 60. High pressure accumulator

61. Orifice 70. Auxiliary damper 71. Damping cylinder

72 .. Damping piston 721. Dustproof plate 722. O-ring

73. Shock spring 100. Modulator block

The present invention for achieving the above object is to reduce the pressure to open the NO-type solenoid valve, NC-type solenoid valve, NC-type solenoid valve mounted on the modulator block to control the braking hydraulic pressure to the hydraulic brake side provided on the front wheel and the rear wheel of the vehicle Low pressure accumulator in which oil escaped from hydraulic brake side is temporarily stored during braking action, and a pair of pumps and pumps operated with a phase difference to supply oil stored in low pressure accumulator to hydraulic brake side during boost pressure braking action. In the vehicle anti-lock brake system having a high-pressure accumulator connected in series to the outlet end of the high pressure accumulator is provided in the outlet side so that the pressurized oil flows in accordance with the pumping operation and the pressure pulsation is reduced,

At the outlet end of the pump, an auxiliary damper disposed in parallel with the high-pressure accumulator is provided so as to reduce the pressure pulsation according to the pump driving.

Hereinafter, one preferred embodiment according to the present invention will be described in detail with reference to the accompanying drawings. 2 is a schematic hydraulic system diagram of an anti-lock brake system for a vehicle according to the present invention, and FIGS. 3 and 4 are cross-sectional views and a perspective view of a damping piston of an auxiliary damper according to the present invention.

The anti-lock brake system for a vehicle according to the present invention is provided with a power boosting device 11 and a master cylinder 12 for forming a boost and braking hydraulic pressure by the operation of the brake pedal 10, as shown in the front wheel ( The hydraulic control mechanism is compactly incorporated in the modulator block 100 to control the braking hydraulic pressure transmission to the hydraulic brake 20 side installed on the FR, FL and the rear wheels RR, RL, respectively.

The modulator block 100 is provided with solenoid valves 30 and 31 so as to control the hydraulic flow to each hydraulic brake 20 side, which is a normally open solenoid valve (30, hereinafter referred to as an NO solenoid valve) associated with the inlet side. And a normal closed solenoid valve 31 (hereinafter referred to as an NC solenoid valve) associated with the outlet side.

The hydraulic line connecting the discharge port side of the NC type solenoid valve 31 and the master cylinder 12 on the front wheel FR, FL side and the rear wheel RR, RL side is a type of damping chamber to reduce oil pressure pulsation. The accumulator 40 and the high pressure accumulator 60 are provided, respectively.

In addition, a pair of pumps 51 are provided between the low pressure accumulator 40 and the high pressure accumulator 60, which are pumped by a single driving motor 50, and are pressurized and discharged from the pump 51. Pressure pulsations have a phase difference of 180 degrees. As a result, the oil discharged from the hydraulic brake 20 during the opening operation of the NC type solenoid valve 31 according to the depressurization braking is temporarily stored in the low pressure accumulator 40, and in the low pressure accumulator 40 in the boost mode. The stored oil is pressurized and supplied to the high pressure accumulator 60 according to the operation of the pump 51.

At this time, a pressure pulsation is generated by a pair of pumps 51 operating with a phase difference of 180 degrees. As a means for attenuating this, the high pressure accumulator 60 configured in series with the outlet end side of the pump 51 is formed. Orifices 61 are provided at the outlet end side, respectively, and auxiliary dampers 70 are formed in parallel with the high pressure accumulator 60, respectively.

Auxiliary damper 70 is built in the damping cylinder 71, the damping cylinder 71 processed in the modulator block 100 to be able to move up and down vertically and the small diameter portion 723 is reduced in diameter at the top center It is comprised largely by the damping piston 72 etc. which were provided.

The damping cylinder 71 has a first port 711 connected to the outlet end side of the pump 51 at the bottom thereof, and a second port 712 connected to the outlet end side of the high pressure accumulator 60 at the top thereof. It is prepared. In addition, an upper cylinder of the damping cylinder 71 is bore-processed so that the auxiliary cylinder 713 into which the small diameter portion 723 of the damping piston 72 is inserted is relaxed.

In addition, the damping piston 72 that moves up and down in the damping cylinder 71 has an O-ring 722 installed at an outer circumferential surface thereof so that oil introduced into the damping cylinder 71 through the first port 711 is second port. The leakage to the 712 side is prevented, and a disk-shaped anti-vibration plate 721 is attached to the lower end surface of the damping piston 72 so that impact noise is not generated when the damping cylinder 71 comes into contact with the bottom surface. In addition, the upper end of the damping piston 72 is provided with a buffer spring 73 for biasing it in a downward direction, so that the vibration damping plate 721 of the damping piston 72 is normally damped by the elastic bearing force of the damping cylinder 71. It is maintained in contact with the lower surface, when the oil pressure flows into the damping cylinder 71 through the first port 711, the oil pressure is attenuated by its buffering force.

As a result, a part of the oil pressure pressurized and discharged by the pair of pumps 51 operated with the phase difference is supplied to the high-pressure accumulator 60 side and discharged through the orifice 61 having the cross-sectional area, thereby reducing the pressure pulsation. The remaining portion is temporarily stored as the pressure pulsation is attenuated by the damping piston 72 embedded in the damping cylinder 71 through the first port 711 and embedded therein. That is, the oil pressure transmitted to the inside of the damping cylinder 71 through the first port 711 pushes the damping piston 72 upward while overcoming the elastic force of the shock absorbing spring 73, thereby driving the pump 51. The generated pressure pulsation is significantly attenuated, as detailed in the description of operation.

Meanwhile, whether the driving motor 50 is operated and all opening and closing operations of the solenoid valves 30 and 31 are performed by an ECU (not shown), which is installed at the front wheels FR and FL and the rear wheels RR and RL. The braking pressure and the rising speed are controlled based on a signal input from each wheel sensor (not shown).

Next, the braking action of the vehicle antilock brake system according to the present invention configured as described above will be described.

First, the driver depresses the brake pedal 10 to decelerate the vehicle or maintain the stopped state while the vehicle is being driven or stopped. As a result, a boosting force amplified than the input is formed in the boosting device 11, and thus, a braking hydraulic pressure of a considerable pressure is generated in the master cylinder 12. The braking hydraulic pressure is transmitted to the hydraulic brakes 20 provided on the front wheels FR and FL and the rear wheels RR and RL through the NO-type solenoid valve 30, whereby a braking action is performed.

When the driver releases little or completely from the brake pedal 10, the oil pressure in each hydraulic brake 20 is returned to the master cylinder 12 through the NO type solenoid valve 30 to reduce the braking force or The braking action is completely released.

On the other hand, while controlling the braking force increase / maintenance state for the purpose of decelerating or stopping while driving the vehicle, the frictional force in the hydraulic brake 20 generated by the braking pressure due to the braking pressure is increased by the driver increasing the braking pressure than the road surface state If the tire is larger than the braking force generated from the tire or the road surface, the vehicle slips on the road surface. Accordingly, the vehicle loses steering power and increases the braking distance, and also requires ABS control because the vehicle rotates. The ABS control is controlled in three modes such as boosting, depressurizing, and maintaining, and each control state is not controlled to the same state on both the front wheel and the rear wheel of the vehicle, and is separately controlled according to the road condition and the ABS control state. Branch modes are mixed and controlled.

First, the pressure reduction operation of the vehicle anti-lock brake system according to the present invention. If the braking pressure in the hydraulic brake 20 in the state of braking is greater than the road surface condition, it should be lowered to an appropriate pressure. Accordingly, in the ECU, the NC type solenoid valve 31 is opened and operated so that oil exiting from the hydraulic brake 20 is temporarily stored in the low pressure accumulator 40 along the hydraulic line. At this time, the opening operation of each NC solenoid valve 31 is performed simultaneously or separately. Through this process, the braking pressure of the hydraulic brake 20 mounted on the front wheels FR and FL and the rear wheels RR and RL is lowered, thereby preventing the sliding phenomenon on the road surface.

And the pressure-increasing operation of the vehicle anti-lock brake system according to the present invention is as follows. When the decompression state lasts for a long time during ABS control or the vehicle moves to a place where the friction coefficient of the road surface is high, the friction force that can be generated on the vehicle tire and the road surface than the braking pressure in the hydraulic brake 20 can be applied. This increases the vehicle braking efficiency. If this situation is determined by the ECU, the pumping operation is performed in the pair of pumps 51 by driving the drive motor 50 to increase the braking pressure in the hydraulic brake 20. Accordingly, the oil stored in the low pressure accumulator 40 is pressurized and supplied into the high pressure accumulator 60 by the pump 51 during the ABS pressure reduction operation. And this is transmitted to the hydraulic brake 20 through the open-type NO solenoid valve 30, thereby increasing the braking hydraulic pressure.

In addition, the pressure in the hydraulic brake 20 reaches the pressure generating the optimum braking force in the ABS control, or in order to prevent the resonance phenomenon of the vehicle derived from the ABS control, an operating state that maintains the pressure is required. The operation is as follows. The pressure holding state to prevent the pressure change in the hydraulic brake 20 mounted on the front wheels FR, FL and the rear wheels RR, RL of the vehicle is the hydraulic brake 20 to maintain the pressure in the NO solenoid valve 30. The oil pressure discharged through the orifice 61 of the high pressure accumulator 60 is transmitted to the master cylinder 12 side by closing the hydraulic side by closing the one side).

On the other hand, during the pressure boosting operation or during the pressure holding operation, a regular half-wave pressure pulsation is generated by a pair of pumps 51 driven with a phase difference of 180 degrees by one drive motor 50, which is a high pressure. It is attenuated by the accumulator 60 and the auxiliary damper 70.

That is, a part of the oil pressure pumped through the outlet end side of the pump 51 is supplied to the high-pressure accumulator 60 arranged in series, and most of the pressure pulsation passes through the orifice 61 installed so as to have a cross-sectional area difference. Is attenuated.

The remaining portion of the oil pressure is supplied into the damping cylinder 71 arranged in parallel with the high pressure accumulator 60 through the first port 711, as shown in FIG. 5, to the shock absorbing spring 73. Pressure pulsation is attenuated in the process of pushing the supported damping piston 72 upward. At this time, although the oil pressure is applied to both ends of the first port 711 and the second port 712, the damping piston 72 is pushed upward, the small diameter portion having a small cross-sectional area at the top of the damping piston 72. (723).

Subsequently, when the oil pressure flowing into the first port 711 is lowered, the damping piston 72 is restored by the elastic force of the shock absorbing spring 73. The vibration damping plate 721 attached to the end surface of the damping piston 72 is restored. No impact noise is generated in the process of restoring.

As a result, the pressure pulsation of the regular semi-square wave is eliminated through the high pressure accumulator 60 and the orifice 61 and the auxiliary damper 70 disposed in parallel thereto, and the uniform oil pressure is reduced to the master cylinder 12. B is transmitted to the NO solenoid valve 30 side.

As described in detail above, the damping device of the vehicle anti-lock brake system according to the present invention is provided with a separate auxiliary damper in parallel with the high-pressure accumulator provided with an orifice on the outlet end side of the pump. Therefore, the regular pressure pulsation generated by the pump driving is completely attenuated through the high pressure accumulator and the auxiliary damper, thereby reducing the overall operating noise and improving the reliability of the ABS.

Claims (4)

The NO type solenoid valve 30 and the NC type solenoid valve (30) mounted on the modulator block 100 to control the braking hydraulic pressure to the hydraulic brake 20 provided on the front wheels FR, FL and rear wheels RR, RL of the vehicle. 31), the low-pressure accumulator 40, the low-pressure accumulator 40, the oil is discharged temporarily from the hydraulic brake 20 side during the decompression braking action of the NC-type solenoid valve 31 is opened A pair of pumps 51 having a phase difference to be supplied to the hydraulic brake 20 side by pressurizing the oil stored in the pump to be supplied to the hydraulic brake 20 side, are connected in series to the outlet end of the pump 51 in accordance with the pumping operation In the vehicle anti-lock brake system having a high-pressure accumulator (60) provided with an orifice (61) on the outlet side so that pressurized oil is introduced and pressure pulsation is reduced, The vehicle anti-lock is provided on the outlet end side of the pump 51 is provided with an auxiliary damper 70 disposed in parallel with the high-pressure accumulator 60 to attenuate the pressure pulsation according to the driving of the pump 51. Damping device for brake system. The method of claim 1, The auxiliary damper 70 has a first port 711 is formed in the lower portion so as to be connected to the outlet end side of the pump 51 and connected to the outlet end side passing the orifice 61 of the high-pressure accumulator 60 at the upper portion. A damping cylinder 71 having a second port 712 formed therein, a damping piston 72 having an O-ring 722 installed on an outer circumferential surface of the damping cylinder 71, and having an O-ring 722 installed on an outer circumferential surface thereof. ) Is provided with a buffer spring (73) installed on the damping piston (72) so that the oil pressure flowing through the first port (711) when the pump 51 is driven to elastically support the downward direction. Damping device for vehicle anti-lock brake system. The method of claim 2, Rubber damp plate 721 is attached to the front end surface of the damping piston (72) to prevent noise generated when the damping cylinder (71) comes into contact with the bottom surface of the damping cylinder (71) by the elastic bearing force of the damping spring (73). A damping device for an anti-lock brake system. The method of claim 3, wherein The upper end of the damping piston 72 is provided with a small diameter portion 723 is reduced in diameter, The anti-lock brake system of the damping cylinder 71 is characterized in that the small-diameter portion 723 is inserted into the upper portion of the damping cylinder 71 with a marginal movement, and an auxiliary cylinder 713 connected with the second port 712 is provided. Damping device.