KR100413316B1 - High pressure accumlator of ABS - Google Patents

Abstract

The present invention relates to a high pressure accumulator of an anti-lock brake system, the object of which is to improve the installation position and components to facilitate assembly and to make the modulator block more compact.

According to the high-pressure accumulator 50 of the anti-lock brake system according to the present invention, the casing in which the valve 53 is built so as to reduce the pressure pulsation of the oil pressurized by the pump 40 during the ABS boosting operation and maintenance operation ( 52 and a cover 54 are mounted coaxially in direct communication with the end of the compression chamber 41 of the pump 40. Accordingly, the configuration of the modulator block 31 is simplified to improve the overall assembly workability of the anti-lock brake system and to reduce manufacturing costs, and to reduce the size of the modulator block 31, thereby providing a more compact configuration. .

Description

High pressure accumlator of ABS

The present invention relates to a vehicle anti-lock brake system, and more particularly, to a high-pressure accumulator of the anti-lock brake system provided in the modulator block to reduce the pressure pulsation of the oil discharged at high pressure when the pump is operating.

In general, the vehicle is equipped with hydraulic brakes mounted on the front and rear wheels for the purpose of decelerating or stopping while driving, and a hydraulic power unit and a master cylinder that forms a braking hydraulic pressure and transmits it to the hydraulic brake side. Is formed and it is transmitted to the hydraulic brake to generate a braking force. However, when the driver presses the brake pedal to control the increase / sustainment of the braking force, if the braking pressure is greater than the road surface state or the frictional force of the hydraulic brake generated by the braking pressure is greater than the braking force generated from the tire or the road surface, the tire is on the road surface. Slipping occurs at the

In order to effectively prevent such slip phenomenon and to obtain a strong and stable braking force, the antilock brake system is provided with a plurality of solenoid valves, accumulators and pumps for controlling the transmission of braking hydraulic pressure to the hydraulic brake side.

That is, referring to FIG. 1, the conventional anti-lock brake system 10 includes a modulator block 11 made of aluminum and a plurality of brake hydraulic pressures mounted on the modulator block 11 to control the braking hydraulic pressure delivered to the hydraulic brake 3. Forcibly pumping oil temporarily stored in the solenoid valve 13A, 13B, a pair of low pressure accumulator 14 and high pressure accumulator 17, and low pressure accumulator 14 for temporarily storing oil. Motor 15 and pump 16 and ECU 12 for controlling the electrically actuated components.

The solenoid valve is divided into a NO type solenoid valve 13A disposed on an upstream side of the hydraulic brake 3 and an NC type solenoid valve 13B disposed on a downstream side, and is controlled by the ECU 12. The ECU 12 detects the vehicle speed through each wheel sensor 4 disposed on the front wheel FR and the rear wheel RR RL, and thereby opens and closes each solenoid valve 13A and 13B. To control.

In addition, the pair of low pressure accumulators 14 are independently provided on the downstream side of the NC type solenoid valve 13B to temporarily store oil escaping from the hydraulic brake 3 side in the decompression mode, and the pair of high pressure accumulators. 17 is a damping chamber, which is arranged to be connected in series with the low pressure accumulator 14, and an orifice 18 is provided at the outlet.

In addition, a pair of pumps 16 driven by one motor 15 is disposed between the low pressure accumulator 14 and the high pressure accumulator 17, and pressurizes the oil in the low pressure accumulator 14. To be pumped to the high pressure accumulator 17 side. The pair of low pressure accumulator 14 and the pump 16, the pair of high pressure accumulator 17, and the plurality of solenoid valves 13A and 13B are mounted on the modulator block 11 compactly.

When the brake pedal 1 is pressed on a vehicle equipped with the conventional anti-lock brake system configured as described above, back force is formed in the power supply device 2, and thereby braking hydraulic pressure is generated in the master cylinder 5. This braking hydraulic pressure is transmitted to each hydraulic brake 3 through the NO-type solenoid valve 13A to perform a braking action.

On the other hand, when excessive braking pressure is transmitted or road surface is slippery than road condition, slip phenomenon occurs that the vehicle slips. ECU 12 slips based on a signal input from the wheel sensor 4 mounted on the wheel of the vehicle. Detect the phenomenon. When a slip phenomenon is detected, the ECU 12 lowers the braking pressure by operating the NC solenoid valve 13B to open to remove oil in the hydraulic brake 3. Subsequently, the oil discharged through the NC type solenoid valve 13B is moved to the pair of low pressure accumulators 14 and stored for a while, and the pressure is increased again via the pump 16 as the motor 15 is driven. Guided to a pair of high-pressure accumulators (17) and fed back to the master cylinder (5) or NO solenoid valve (13A).

At this time, the pair of high-pressure accumulator 17 is configured to have a chamber in the modulator block 11 made of aluminum, as described above, so that the oil discharged at a high pressure from the pump 16 is temporarily stored and the pressure pulsation is Is reduced.

In order to configure the pair of high-pressure accumulators 17, conventionally, a plurality of processes are required to process the bores separately on the side of the modulator block 11 and seal them with plugs, which makes manufacturing difficult. In addition, since the number of parts for the high-pressure accumulator 17 is large, the overall manufacturing cost of the anti-lock brake system 10 increases, and there is a limit to making the modulator block 11 compact.

SUMMARY OF THE INVENTION The present invention has been made to solve this problem, and an object of the present invention is to provide a high-pressure accumulator on the side of the modulator block coaxially with the pump, thereby facilitating its construction and making the modulator block more compact. It is to provide a high pressure accumulator of an anti-lock brake system.

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

2 is a hydraulic system showing an anti-lock brake system for a vehicle according to the present invention.

3 is a cross-sectional view showing a coupling state of the high-pressure accumulator according to the present invention.

4 is an exploded perspective view of the high pressure accumulator according to the present invention.

5 to 7 are cross-sectional views showing a step of assembling the high pressure accumulator according to the present invention.

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

31. Modulator block 32. ECU 33A, 33B Solenoid valve

40. Pump 41. Compression chamber 42. Piston

50. High pressure accumulator 51. Coupling part 52 Casing

53. Outlet valve 54. Cover

The present invention for achieving this object is; In the anti-lock brake system having a modulator block and a pump for reciprocating the compression chamber provided in the modulator block to pressurize and discharge oil during ABS pressure braking or pressure holding braking.

An end portion of the compression chamber is provided with a coupling portion having an inner diameter extending coaxially. It is a structure characterized by including a cover.

In addition, the outer periphery of the cover is provided with a stepped portion in the circumferential direction, the coupling portion is a configuration characterized in that the fixing portion is formed in close contact with the stepped portion is fixed to the cover.

In addition, the oil inlet is provided with a valve for preventing backflow of the oil in the damping chamber, the valve is provided in the oil inlet to move forward and backward movement, the elastic member for elastically supporting the sphere, the elastic member and the sphere oil And a stopper for positioning in the inlet.

In addition, the oil inlet is inserted into the compression chamber, the outer periphery of the oil inlet is a configuration characterized in that the recessed recess formed in the circumferential direction, and a sealing member for preventing the oil leakage is seated in the mounting groove.

According to this configuration, the high-pressure accumulator is disposed on the side of the modulator block coaxially with the compression chamber of the pump, whereby the components can be simplified to facilitate assembly, and the modulator block can be made more compact.

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

2, the vehicle anti-lock brake system 30 according to the present invention for controlling the braking hydraulic pressure transmission to the hydraulic brake 23 side installed on the front wheel (FR) (FL) and the rear wheel (RR) (RL). A plurality of solenoid valves 33A, 33B, a pair of low pressure accumulators 34, in which oil from the hydraulic brake 23 side is temporarily stored during the decompression braking operation, and a storage accumulator during the pressure braking operation. A motor 35 and a pair of pumps 40 for pumping oil stored in the 34 and a pair of high pressure accumulators 50 for reducing pressure pulsation of oil pressurized and discharged by the pump 40 are driven. They are provided in the modulator block 31 compactly.

The plurality of solenoid valves are connected to the upstream and downstream sides of the hydraulic brake 23, and are arranged on the upstream side and are normally connected to the NO type solenoid valve 33A and the downstream which are kept open and are normally closed. It is distinguished by the NC type solenoid valve 33B maintained in the state. The opening / closing operation of the solenoid valves 33A and 33B is respectively performed by the ECU 32 which detects the vehicle speed through the wheel sensors 24 disposed on the front wheel FR and the rear wheel RR RL. It is controlled and the NC type solenoid valve 33B is opened according to the depressurization braking action, and the oil exiting from the hydraulic brake 23 side is temporarily stored in the low pressure accumulator 34.

In addition, the pair of pumps 40 have a predetermined phase difference by the motor 35 and are simultaneously driven to discharge the oil stored in the low pressure accumulator 34 to the pressure high pressure accumulator 50. The oil introduced into the 50 is delivered to the hydraulic brake 23 side or returned to the master cylinder 22 along the hydraulic line while the pressure pulsation is reduced.

The high pressure accumulator 50 performing this function is provided with an outlet valve 53 and coaxially installed with the compression chamber 41 of the pump 40, thereby making the modulator block 31 more compact. Next, a detailed structure of the pump 40 and the high pressure accumulator 50 will be described with reference to FIGS. 3 and 4.

First, the modulator block 31 is provided with a suction port 31A directly connected to the low pressure accumulator 34 side and a discharge port 31B directly connected to the high pressure accumulator 50. In the center of the modulator block 31, a motor 35 and a pair of pumps 40 are symmetrically disposed about the motor 35.

The motor 35 includes an eccentric shaft 35A and a bearing 35B having a predetermined amount of eccentricity, and the pair of pumps 40 simultaneously drive 180 degrees of phase difference as the eccentric shaft 35A rotates.

The pump 40 is provided in a cylindrical shape in the modulator block 31 and is slidably installed in the compression chamber 41 and the compression chamber 41 associated with the suction port 31A and the discharge port 31B. The piston 42 provided with the suction flow path 42A in the axial direction is provided inside. The suction passage 42A of the piston 42 is connected to the low pressure accumulator 34 through the suction port 31A, and the discharge side of the compression chamber 41 has a discharge port 31B having the orifice 31C disposed thereon. It is connected with the hydraulic line through the master cylinder 22 and the hydraulic brake 23 side.

In addition, according to the position of the piston 42, the suction flow path 42A and the discharge side flow path are opened and closed oppositely. For this purpose, an inlet valve 43 and an outlet valve 53, which are a kind of check valve, are provided. The inlet valve 43 includes a sphere 43A disposed in the suction passage 42A, an elastic member 43B and a retainer 43C for elastically supporting the sphere 43A. The outlet valve 53 also has a spherical 53A, an elastic member 53B, and a disc-shaped stopper 53C with an open central portion disposed on the oil inlet side of the high-pressure accumulator 50, thereby preventing backflow of oil. Done. Reference numeral 44 is a return spring for restoring the piston 42.

The high-pressure accumulator 50 is press-fitted so as to be in direct communication with the compression chamber 41. For this purpose, the high-pressure accumulator 50 is coaxially viewed at the opening end of the compression chamber 41, so that the discharge port 31B communicates with the inner side thereof. This expanded engaging portion 51 is provided. The high-pressure accumulator 40 installed in the coupling portion 51 has a cylindrical casing 52 having an oil inlet 52A at one end thereof and an open end thereof, and a cover covering the opening of the casing 52 ( 54).

The casing 52 having the oil inlet 52A is formed in a cylindrical shape to form a damping chamber 52B therein, and a discharge hole 52C is formed at a side thereof so as to communicate with the discharge port 31B. The oil inlet 52A is provided to protrude in the closed surface of the casing 52, and is fitted into the compression chamber 41 to be coupled. In addition, at the outer circumference of the oil inlet 52A, an elastic sealing member 52D for preventing oil leakage is provided. Sealing member (52D) is composed of a kind of O-ring (O-RING), the installation groove 52E is provided in the circumferential direction on the outer circumference of the oil inlet (52A) for its installation.

Inside the oil inlet 52A, the outlet valve 53 is provided as described above. That is, the sphere 53A of the outlet valve 53 is built in the oil inlet 52A so as to move forward and backward, and the stopper 53C closes the casing 52 so that the coil spring type elastic member 53B does not escape. The sphere 53A is elastically supported in the direction of closing the oil inlet 52A by being seated on the sheet portion 52F provided on the surface and fixed through a clinching step.

In addition, the cover 54 is coupled to cover the opening of the casing 52 to form a complete damping chamber 52B, the outer periphery of the fixing step for fixing the casing 52 to the coupling portion 51 firmly The portion 54A is provided in the circumferential direction.

The high pressure accumulator 50 having the casing 52 and the cover 54 includes a clinching step of assembling the outlet valve 53 and a loading step of preliminarily assembling the casing 52. And it is firmly coupled to the coupling portion 51 through a staking step of fixing it again firmly.

That is, the cinching step is a step of assembling the outlet valve 53 to the high-pressure accumulator 50, as shown in Figure 5, the oil inlet 52A and the sphere 53A and the elastic member 53B and After the stopper 53C is disposed sequentially, the closing surface of the casing 52 is locally deformed (X region) along the edge of the stopper 53C using a clinching tool (not shown). As a result, an outlet valve 53 is provided in the oil inlet 52A.

In addition, the loading step is to temporarily assemble the high-pressure accumulator (50) manufactured through such a clutching step to the coupling unit 51, as shown in Figure 6, assembling the casing 52 and the cover 54 Then, they are inserted into the coupling part 51 such that the oil inlet 52A is received into the compression chamber 41 in which the return spring 44 is built. At this time, the sealing member 52D provided at the outer circumference of the oil inlet 52A is compressed to prevent oil leakage.

Subsequently, the staking step is a step of finally fixing the casing 52 and the cover 54 to the modulator block 31 through the staking tool 60 to complete the high pressure accumulator 50. . Referring to FIG. 7, this step applies pressure in the direction of the arrow Y using the staking tool 60 at the end of the engaging portion 51 in contact with the edge of the cover 54. As a result, a part of the modulator block 31 is deformed, and a fixing part 51A close to the fixing step 54A of the cover 54 is formed, thereby providing the casing 52 and the cover 54. The high pressure accumulator 50 is firmly mounted to the modulator block 31 coaxially with the compression chamber 41 and the discharge hole 52C communicates with the discharge port 31B.

Next, the operation and effect of the high-pressure accumulator 50 according to the present invention assembled through such a series of steps will be described.

First, the driver steps on the brake pedal 20 to decelerate the vehicle while the vehicle is running or in a stopped state, or to maintain the stopped state. In the case of a normal braking operation, a boosting power amplified than the input is formed in the power booster 21. This generates a significant pressure braking hydraulic pressure in the master cylinder (22). This braking hydraulic pressure is transmitted to the hydraulic brake 23 side through the NO type solenoid valve 33A, whereby a braking action of the vehicle is achieved. When the driver releases the brake pedal 20 little by little or completely, the oil pressure in the hydraulic brake 23 is returned to the master cylinder 22 again through the NO-type solenoid valve 33A and the braking force is reduced or the braking action is performed. This is completely released.

The frictional force of the hydraulic brake 23 generated by the brake pressure due to the braking pressure is increased when the driver increases the braking pressure to the road surface state or changes the road surface condition while controlling the braking force to increase / maintain for the purpose of deceleration or stop while driving. If the braking force generated from the tire or the road surface is greater than that, a slip phenomenon occurs that the tire slips on the road surface. As a result of the slip phenomenon, the vehicle loses steering power and increases the braking distance, and the ABS rotates because the vehicle rotates. The ABS is controlled in three modes, such as decompression, boosting, and holding, based on signals input from the wheel sensors 24 disposed in the front wheels FR and FL, respectively. The control state is not controlled to the same state in both the front wheel FR and the rear wheel RR RL, but is controlled separately according to the friction condition, that is, the three modes are mixed.

First, the braking pressure decompression operation of the vehicle vehicle antilock brake system 30 will be described. If the braking pressure in the hydraulic brake 23 is greater than the road surface condition while braking is being performed, the braking pressure should be lowered to an appropriate pressure. Accordingly, the ECU 32 opens and operates the NC type solenoid valve 33B so that the oil coming out of the hydraulic brake 23 is temporarily stored in the low pressure accumulator 34. At this time, the opening operation of each NC solenoid valve 33B is performed simultaneously or separately. Through this process, the pressure of the hydraulic brake 23 mounted on the front wheel FR and the rear wheel RR RL side is lowered to prevent the sliding phenomenon on the road surface.

The braking pressure boosting operation of the antilock brake system 30 is as follows. If the ABS depressurization state lasts for a long time during ABS control or the vehicle proceeds to a place where the friction coefficient of the road surface is high, the friction force that can be generated on the tire and the road surface is more than that the brake pressure can be braked by the braking pressure in the hydraulic brake 23. The increase in the braking efficiency of the vehicle occurs.

In this case, the driving pump 40 operates the motor 35 to increase the braking pressure in the hydraulic brake 23 based on the signals input from the wheel sensors 24. . As the piston 42 incorporated in the pump 40 compression chamber 41 reciprocates, the opening and closing operation of the inlet valve 43 is repeatedly performed, and the low pressure accumulator 34 is opened at the moment of opening of the inlet valve 43. ) Is stored in the compression chamber 41 through the suction port 31A and the suction flow path 42A. The oil in the compression chamber 41 is then pressurized by the reciprocating motion of the piston 42 to open the outlet valve 53 and discharged into the high pressure accumulator 50. That is, the pressurized oil is discharged to the damping chamber 52B formed in the casing 52 while pressing the sphere 53A to compress the elastic member 53B, thereby reducing the pressure pulsation of the oil.

Subsequently, the pressurized oil having reduced pressure pulsation is discharged to the hydraulic line through the outlet hole 52C, the orifice 31C, and the discharge port 31B, and the hydraulic brake 23 through the open-type NO solenoid valve 33A. The braking hydraulic pressure is increased by passing through.

Meanwhile, in order to prevent the braking pressure in the hydraulic brake 23 from generating the optimum braking force in the ABS control or to prevent resonance of the vehicle derived during the ABS control, the braking pressure maintaining operation maintains the braking pressure in a constant state. This is necessary. That is, the pressure holding operation eliminates the pressure change in the hydraulic brake 23 mounted on the front wheel FR and the rear wheel RR of the vehicle, which causes the hydraulic brake 23 to maintain the braking pressure. The NO-type solenoid valve 33A on the side is closed to block hydraulic pressure from being transmitted. Accordingly, the pressurized oil discharged through the high pressure accumulator 50 in a state where the pressure pulsation is reduced is transferred to the master cylinder 22 side, whereby the braking pressure maintenance operation is performed.

As described in detail above, according to the high-pressure accumulator of the anti-lock brake system according to the present invention, the casing and the cover with a built-in valve to reduce the pressure pulsation of the oil pressurized by the pump during ABS boosting operation and maintenance operation It is provided coaxially in direct communication with the end of the compression chamber of the pump. Accordingly, the configuration of the modulator block is simplified to improve the overall assembly workability of the anti-lock brake system and to reduce the manufacturing cost, and to reduce the size of the modulator block, thereby providing a more compact configuration.

Claims (4)

In the anti-lock brake system having a modulator block and a pump for reciprocating the compression chamber provided in the modulator block to pressurize and discharge oil during ABS pressure braking or pressure holding braking. An end portion of the compression chamber 41 is provided with a coupling part 51 having an inner diameter expanded coaxially, Directly coupled to the end of the coupling portion 51 and the oil inlet 52A is formed on one side and the other end is open casing 52, And a cover (54) covering the opening of the casing (52) so that a damping chamber (52B) is formed in the casing (52). The method of claim 1, On the outer circumference of the cover 54, a stepped portion 54A is provided in the circumferential direction, The coupling portion (51) is a high-pressure accumulator of the anti-lock brake system, characterized in that the fixing portion (51A) in close contact with the step (54A) is formed so that the cover (54) is fixed. The method of claim 1, The oil inlet 52A is provided with a valve 53 for preventing oil in the damping chamber 52B from flowing back. The valve 53 has a sphere 53A embedded in the oil inlet 52A so as to move forward and backward, an elastic member 53B for elastically supporting the sphere 53A, the elastic member 53B, and the sphere. And a stopper (53C) for disposing (53A) in said oil inlet (52A). The method of claim 2, The oil inlet 52A is inserted into the compression chamber 41, The outer periphery of the oil inlet (52A) is characterized in that the mounting recess 52E formed in the circumferential direction and a sealing member (52D) is provided in the mounting groove (52E) to prevent oil leakage High pressure accumulator with lock brake system.