KR20030075651A - Pump of electronic control brake system - Google Patents

Abstract

PURPOSE: A pump for an electronic control brake system is provided to reduce manufacturing expenses and hours by simplifying the structure of a piston with arranging a suction passage and a discharge passage in a valve housing, and to improve efficiency of the pump by decreasing flow resistance of oil with shortening the flow distance of oil. CONSTITUTION: A valve housing(44) is arranged in the end of a piston(50), and a compression chamber(43) compressing oil is placed between the piston and the valve housing. A suction passage(44a) and a discharge passage(44b) are integrally formed in the valve housing and communicated with the compression chamber. Inlet and outlet valves(51,55) are arranged in the suction and discharge passages. A sleeve(44c) is integrally formed in the valve housing, and extended outside the piston. A piston guide(60) is installed between the end of the piston and the sleeve, and a seal is attached to the piston guide to prevent oil from the compression chamber from leaking out of the piston. A stopper(62) is protruded vertically from the rear end of the piston, and a return spring(63) is mounted between the stopper and the piston guide.

Description

Pump of electronic control brake system

The present invention relates to an electronically controlled brake system, and more particularly, to a pump of an electronically controlled brake system for sucking low pressure oil on the low pressure accumulator or reciprocating hydraulic valve side and forcibly pumping it to the high pressure accumulator side.

In general, the electronically controlled brake system effectively prevents the slip of the vehicle and obtains a strong and stable braking force. The electronically controlled brake system uses an anti-lock brake system (ABS: Anti-Lock Brake) to prevent the wheel from slipping during braking. System), the brake traction control system (BTCS: Brake Traction Control System) which prevents slippage of the driving wheel during sudden start or acceleration of the vehicle, and anti-lock brake system and traction control in combination to control the brake hydraulic pressure A vehicle dynamic control system (VDC) has been developed to keep the vehicle stable.

The electronically controlled brake system includes a plurality of solenoid valves for controlling the braking hydraulic pressure delivered to the hydraulic brake side mounted on the wheel of the vehicle, a pair of low pressure accumulators and high pressure accumulators for temporarily storing oil discharged from the hydraulic brakes, It includes a motor and pump for forcibly pumping oil in the low pressure accumulator, and an ECU for controlling the solenoid valves and the operation of the motor. These components are compactly embedded in a modulator block made of aluminum.

Therefore, by the operation of the pump, the low pressure oil in the low pressure accumulator is pressurized and pumped to the high pressure accumulator, and the pressurized oil is transferred to the hydraulic brake or master cylinder assembly side. The pump is driven by a motor, which shows a conventional pump applied to an electronically controlled brake system.

Referring to FIG. 1, a conventional pump 10 is installed in a bore 5 formed in a modulator block 1 to reciprocate by an eccentric spindle 2a of a motor 2, and a suction flow path 6a therein. Is provided with a piston 6, an inlet valve 7 for opening and closing the outlet side of the suction passage 6a according to the position of the piston 6, and an inlet valve 7 with an open end of the bore 5. It is provided with an outlet valve (8) which operates in opposition.

The modulator block 1 has a suction port 3 for communicating the inlet side of the suction passage 6a formed in the piston 6 with the low pressure accumulator side, and the inlet side and the outlet of the high pressure accumulator (not shown). A discharge port 4 for communicating the outlet side of the valve 8 is formed.

An inlet valve 7 is provided at the tip of the piston 6, and a seal 9 is provided on the outer periphery of the piston 6 to prevent oil from leaking through a clearance with the inner wall of the bore 5. . The seal 9 has a ring shape and is disposed in the recess 6b recessed along the outer periphery of the piston 6.

The outlet valve 8 is seated on the valve cap 12 provided in the bore 5 of the modulator block 1 and the valve seat 11 embedded in the valve cap 12.

In the conventional pump 10 configured as described above, the piston 6 linearly reciprocates as the eccentric spindle 2a of the motor 2 rotates, and the inlet valve 7 is opposed to each other by a pressure change in the bore 5. And the outlet valve 8 open and close to pressurize the introduced oil to pump the high pressure accumulator.

That is, when the piston 6 moves to the top dead center, the pressure of the oil between the piston 6 and the outlet valve 8 increases, whereby the inlet valve 7 is closed and the outlet valve 8 is closed by the valve seat ( By opening away from 11, the oil is pumped through the discharge port 4 to the high pressure accumulator side.

On the other hand, when the piston 6 moves to the bottom dead center, a low pressure is formed in the space between the tip of the piston 6 and the outlet valve 8, which opens the inlet valve 7 and the outlet valve 8 ) Is seated on the valve seat 11 and closed so that the oil on the low pressure accumulator side passes between the piston 6 and the outlet valve 8 through the suction port 3, the suction flow path 6a and the inlet valve 7. Flows into space.

However, in the pump of the conventional electronically controlled brake system, a suction port for introducing oil is formed at a position corresponding to the middle portion of the piston in the modulator block, and a discharge port for discharging oil is provided at the tip of the piston in the modulator block. Because the structure is formed in the position beyond, the piston must be provided with an inlet flow passage formed inevitably through the inside so that the oil passing through the suction port toward the discharge port, the piston structure is complicated At the same time, as the flow path of the oil is formed relatively long inside the pump, the flow resistance is increased, so that the efficiency of the pump is lowered.

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 pump of an electronically controlled brake system in which the suction flow path and the discharge flow path are arranged in the valve housing to simplify the structure of the piston and reduce the flow resistance of oil. It is.

1 is a cross-sectional view showing a pump configuration of a conventional electronically controlled brake system.

2 is a hydraulic system diagram of an anti-lock brake system to which the present invention is applied.

3 is a cross-sectional view showing the internal structure of the pump according to the present invention.

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

31 ... Modulator block 31a ... Bore

40 ... pump 43 ... compression chamber

44.Valve housing 44a ... Suction channel

44b ... Discharge Euro 44c ... Sleeve

50 ... piston 51 ... inlet valve

55 outlet valve 60 piston guide

62 ... stopper 63 ... return spring

The present invention for achieving this object is provided in the modulator block having a piston reciprocating by the drive of the motor coupled to the eccentric shaft, an inlet valve and an outlet valve alternately opened and closed by the reciprocating motion of the piston. In the pump of the electronically controlled brake system installed in the bore,

A valve housing is disposed at the front end of the piston, and a compression chamber for compressing the oil introduced therein is provided between the piston and the valve housing, and the suction and discharge passages are integrally formed in the valve housing in communication with the compression chamber. The inlet valve and the outlet valve are each disposed in the suction passage and the discharge passage formed in the valve housing.

The compression chamber is provided with an inlet spring retainer having at least one through hole formed therein, and an inlet spring is disposed between the inlet spring retainer and the inlet valve, and the inlet valve is discharged from the suction flow path by the inlet spring. Biased to close contact with

In addition, an outlet spring retainer is installed at an outlet of the discharge passage, and an outlet spring is disposed between the outlet valve and the outlet spring retainer, and the outlet valve is biased to be in close contact with the inlet of the discharge passage by the outlet spring. .

The valve housing is integrally provided with a sleeve extending to the outer circumferential surface of the piston, a piston guide having a predetermined length is installed between the front end of the piston and the sleeve, the oil of the compression chamber is provided in the piston guide A seal is attached to prevent leakage through the outer circumferential surface.

A stopper protruding perpendicularly from the outer circumferential surface of the piston is installed at the rear end of the piston, and a return spring is installed between the stopper and the piston guide. When the piston moves toward the top dead center, the return spring is moved by the stopper. When the piston reaches the top dead center, the return spring is elastically restored to move the piston toward the bottom dead center.

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

2 shows a hydraulic system diagram of an anti-lock brake system to which a pump according to the present invention is applied.

Referring to FIG. 2, the anti-lock brake system to which the present invention is applied includes a plurality of solenoid valves 33A and 33B for controlling the transmission of braking hydraulic pressure to the hydraulic brake 23 side installed on the front wheel and the rear wheel, and the pressure reducing braking system. A low pressure accumulator 34 in which oil escaping from the hydraulic brake 23 side is temporarily stored in operation, a pair of pumps 40 for pumping oil stored in the low pressure accumulator 34 in a boost / hold braking operation; And one motor 35 for simultaneously driving the pair of pumps 40, and an orifice 36a is disposed at the outlet side to reduce pressure pulsation of oil pressurized and discharged by the driving of the pump 40. It is equipped with a high-pressure accumulator 36, these components are compactly embedded in a cuboid-shaped modulator block 31 made of aluminum.

The plurality of solenoid valves 33A and 33B are associated with the upstream side of the hydraulic brake 23 and are normally connected with the NO type solenoid valve 33A that is kept open and the downstream side of the hydraulic brake 23 and normally It is distinguished by the NC type solenoid valve 33B which is kept closed. The opening and closing operations of the solenoid valves 33A and 33B are respectively controlled by the ECU 32 which detects the vehicle speed through the wheel sensors 24 disposed on the front wheels and the rear wheels. In addition, the NC type solenoid valve 33B is opened in response to the depressurizing braking action, and the oil discharged from the hydraulic brake 23 side is temporarily stored in the low pressure accumulator 34.

In addition, the pair of pumps 40 are driven while having a certain phase difference by one motor 35 to pressurize the oil stored in the low pressure accumulator 34 to pump the high pressure accumulator 36. The structure of the pump will be described with reference to FIG.

Here, since the pair of pumps 40 are symmetrical with respect to the eccentric spindle 35a of the motor 35, only one pump structure is enlarged in FIG. 3 for convenience.

As shown in FIG. 3, one motor 35 is provided at the central portion of one side of the modulator block 31 to protrude the spindle 35a to drive a pair of pumps 40 disposed on the left and right sides. . The spindle 35a of the motor 35 is integrally formed with the eccentric shaft 35b and disposed between the pistons 50 of the respective pumps 40, so that the pair of pumps 40 are connected to one motor 35. As a result, they are driven while having a phase difference of 180 degrees from each other.

The pump 40 according to the present invention includes a bore 31a formed to be open to the modulator block 31 in the lateral direction, a piston 50 disposed reciprocally from side to side within the bore 31a, and a bore ( A valve housing 44 coupled to seal the open end of 31a) to form a compression chamber 43 between the tip of the piston 50, and an inlet valve 51 provided inside the valve housing 44; And an outlet valve 55.

The valve housing 44 is provided with a suction flow path 44a and a discharge flow path 44b radially formed to communicate with the suction port 31b and the discharge port 31c formed in the modulator block 31, respectively. 43 is located between the outlet of the suction passage 44a and the inlet of the discharge passage 44b. Therefore, the oil flowing into the suction port 31b is sent to the compression chamber 43 through the suction flow path 44a and compressed by the piston 50, and then through the discharge flow path 44b and the discharge port 31c. It will be discharged.

The inlet valve 51 is seated on or separated from the valve seat 52 formed at the outlet of the suction passage 44a to open and close the suction passage 44a. For this purpose, the inlet spring is disposed in the compression chamber 43 in the transverse direction. A retainer 53 is provided, and between the inlet spring retainer 53 and the inlet valve 51 is an inlet spring 54 which biases the inlet valve 51 to the valve seat 52 formed in the suction flow path 44a. It is arranged.

At least one through hole 53a is formed in the inlet spring retainer 53 so that oil in the compression chamber 43 can communicate with the suction passage 44a and the discharge passage 44b.

On the other hand, the outlet valve 55 is seated or separated from the valve seat 56 formed at the inlet of the discharge flow path (44b) to open and close the discharge flow path (44b), for this purpose, the outlet spring retainer at the outlet of the discharge flow path (44b) A 57 is provided, and an outlet spring 58 is disposed between the outlet spring retainer 57 and the outlet valve 55 to bias the outlet valve 55 to the valve seat 56 formed in the discharge passage 44b. It is.

As described above, the sleeve 44c is provided at the rear end of the valve housing 44 in which the inlet flow passage 44a and the discharge flow passage 44b provided with the inlet valve 51 and the outlet valve 55, respectively, are formed. It is formed integrally extending from the housing 44 and spaced apart from the outer circumferential surface of the piston 50 by a predetermined interval.

In addition, a piston guide 60 press-fitted between the sleeve 44c and the piston 50 at the distal end of the piston 50 and the distal end thereof is in contact with the inlet spring retainer 53 is disposed to reciprocate the piston 50. The first seal 61 is formed in an annular shape and its longitudinal section is formed in an approximately X shape at an approximately intermediate point of the piston guide 60. The first seal 61 prevents the oil in the compression chamber 43 from leaking between the outer circumferential surface of the piston 50 and the inner circumferential surface of the piston guide 60 during the reciprocating movement of the piston 50.

In addition, a stopper 62 protruding from the outer circumferential surface of the piston 50 at a predetermined length vertically is provided at the rear end of the piston 50, and between the stopper 62 and the rear end of the piston guide 60. The return spring 63 is provided. Therefore, when the piston 50 moves to the top dead center, the return spring 63 is compressed by the stopper 62, and when the piston 50 moves to the bottom dead center, the return spring 63 is originally It is elastically restored to the position of.

A second seal 64 is provided between the rear end of the piston 50 and the bore 31a of the modulator block 31, so that the bore of the piston 50 and the modulator block 31 during reciprocating movement of the piston 50 is provided. This prevents oil from leaking between 31a). The stopper 62 formed to protrude vertically from the piston 50 is disposed at a predetermined distance from the front of the second seal 64.

Next, the operation and effect of the anti-lock brake system to which the pump 40 according to the present invention configured as described above is applied will be described.

Since the anti-lock brake system controls the braking state of the vehicle according to the braking pressure decompression mode, the boosting mode, and the holding mode to prevent slippage of the vehicle, each solenoid valve ( 33A) 33B is operated to open or close repeatedly with the operation of the pump 40. That is, when the braking pressure in the hydraulic brake 23 is greater than the frictional force of the road in a state where the driver presses the brake pedal 20 and the braking force is exerted by the braking hydraulic pressure formed through the power booster 21 and the master cylinder assembly 22. In this case, the ECU 32 closes the NO solenoid valve 33A and opens the NC solenoid valve 33B (see FIG. 2).

If the decompression state of the braking pressure is long or the vehicle moves to a place where the friction coefficient of the road surface is high, the friction force that may be generated on the tire and the road surface of the vehicle should be increased to increase the braking pressure. The ECU 32 determines the situation based on the signals input from the wheel sensors 24 and drives the pump 40 through the motor 35 to increase the braking pressure in the hydraulic brake 23. Accordingly, the oil stored in the low pressure accumulator 34 is pressurized and supplied to the high pressure accumulator 36, and the oil is continuously transferred to the hydraulic brake 23 through the open NO solenoid valve 33A. As a result, the braking hydraulic pressure is increased.

In this boost mode, the oil stored in the low pressure accumulator 34 is pressurized by the driving of the pump 40 and is supplied to the NO type solenoid valve 33A while passing through the high pressure accumulator 36 and the orifice 36a. The operation of the pump 40 according to the present invention will be described in more detail.

As the eccentric spindle 35a of the motor 35 rotates, when the piston 50 slides to the top dead center in the bore 31a (arrow A direction), the return spring 63 moves with the piston 50. The inlet valve 51 is seated on the valve seat 52 and closed while the outlet valve 55 is pressurized by the pressure of the oil pressurized in the compression chamber 43. Opened while compressing the outlet spring 58, the oil pressurized in the compression chamber 43 is discharged to the high-pressure accumulator 36 side through the discharge passage 44b and the discharge port 31c.

On the contrary, when the piston 50 reaches the top dead center, the piston 50 is slid to the bottom dead center by the elastic restoring force of the return spring 63 (arrow B direction), and the back of the piston 50 is moved. The inlet valve 51 is opened while the inlet spring 54 is compressed by the operation of the compression chamber 43 in a low pressure state, while the outlet valve 55 is closed while the outlet spring 58 is elastically restored. The oil on the accumulator 34 side is sucked into the compression chamber 43 through the suction port 31b.

As the reciprocating motion of the piston 50 is continuously performed by the driving of the motor 35, the inlet valve 51 and the outlet valve 55 as described above are alternately opened and closed, and the oil introduced into the compression chamber 43 is performed. This pressurized and discharged operation is repeated.

As described above, the pump of the electronically controlled brake system according to the present invention eliminates the need to form a suction flow path in the piston by arranging the suction flow path and the discharge flow path connected to the compression chamber in the valve housing. The structure is very simple, the manufacturing cost and time is saved.

In addition, since the suction flow path and the discharge flow path are arranged in the valve housing, the flow distance of the oil passing through the pump of the present invention is shortened, thereby reducing the flow resistance of the oil, thereby increasing the efficiency of the pump.

Claims (6)

A pump of an electronically controlled brake system provided in a bore formed in a modulator block, having a piston reciprocating by driving an eccentric shaft, an inlet valve and an outlet valve alternately opened and closed by the reciprocating motion of the piston. To A valve housing is disposed at the front end of the piston, and a compression chamber for compressing the oil introduced therein is provided between the piston and the valve housing, and the suction and discharge passages are integrally formed in the valve housing in communication with the compression chamber. And the inlet valve and the outlet valve are respectively disposed in the suction passage and the discharge passage formed in the valve housing. The method of claim 1, The compression chamber is provided with an inlet spring retainer having at least one through hole formed therein, and an inlet spring is disposed between the inlet spring retainer and the inlet valve, and the inlet valve is discharged from the suction flow path by the inlet spring. The pump of the electronically controlled brake system, characterized in that biased to be in close contact with. The method of claim 2, An outlet spring retainer is installed at the outlet of the discharge passage, and an outlet spring is disposed between the outlet valve and the outlet spring retainer, so that the outlet valve is biased to be in close contact with the inlet of the discharge passage by the outlet spring. Pump of electronically controlled brake system. The method of claim 1, The valve housing is a pump of an electronically controlled brake system, characterized in that integrally provided with a sleeve formed extending to the outer peripheral surface of the piston. The method of claim 4, wherein A piston guide having a predetermined length is installed between the tip of the piston and the sleeve, and the seal is attached to the piston guide to prevent oil from the compression chamber from leaking through the outer circumferential surface of the piston. Pump with controlled brake system. The method of claim 5, A stopper protruding perpendicularly from the outer circumferential surface of the piston is installed at the rear end of the piston, and a return spring is installed between the stopper and the piston guide. When the piston moves toward the top dead center, the return spring is moved by the stopper. Is compressed and the return spring is elastically restored when the piston reaches the top dead center and moves the piston toward the bottom dead center.