KR20050122326A - Pump for anti-lock brake system - Google Patents

Abstract

The present invention discloses a pump for an anti-lock brake system. The disclosed pump is installed in a bore formed in a modulator block to perform a linear reciprocating motion by a rotational axis of a motor, and a piston having a suction flow path therein is provided in the piston. An inlet valve for opening and closing a pump for an anti-lock brake system including a plug provided at an open end of the bore and having an outlet valve for forming a pressure chamber between the piston tip, the piston for guiding the piston. It is installed on the inner surface of the bore so as to surround the end, characterized in that it comprises a guide member formed integrally with the valve seat portion forming the outlet valve between the plug and the plug. The pump for the anti-lock brake system is integrally formed with the valve seat portion and the discharge passage is formed between the guide member and the plug, thereby reducing the number of parts and the assembly process.

Description

Pump for anti-lock brake system {PUMP FOR ANTI-LOCK BRAKE SYSTEM}

The present invention relates to a pump for an antilock brake system, and more particularly, to a pump for an antilock brake system in which a guide member and a valve seat are integrated and a discharge passage is formed between the guide member and a plug.

In general, the anti-lock brake system effectively prevents the sliding of the wheel during braking to obtain a strong and stable braking force, and a plurality of solenoid valves and oil for controlling the braking hydraulic pressure transmitted to the hydraulic brake side mounted on the wheel of the vehicle And a pair of low pressure accumulators and high pressure accumulators for temporarily storing the engine, a motor and pump for forcibly pumping oil temporarily stored in the low pressure accumulator, and an ECU for controlling the operation of the solenoid valve and the motor. It is compactly embedded in a modulator block made of aluminum.

Accordingly, the low pressure oil of the low pressure accumulator is pressurized by the driving of the pump and pumped to the high pressure accumulator, which is transferred to the hydraulic brake or the master cylinder assembly side. Such a pump is driven by a motor, in which Figure 1 shows a conventional pump applied to an antilock brake system.

Referring to FIG. 1, a conventional pump 10 is installed in a bore 5 formed in the modulator block 1 to reciprocate by an eccentric shaft 2a of a motor 2. The pump 10 includes a piston 6 having a suction passage 6a, an inlet valve 7 for opening and closing an outlet side of the suction passage 6a according to the position of the piston 6, an inlet valve 7 and It is equipped with an outlet valve (8) which works in opposition.

The modulator block 1 includes a suction port 3a for linking the inlet side of the piston 6 suction channel 6a with a low pressure accumulator (not shown), an inlet side of the high pressure accumulator (not shown), and an outlet valve 8. Discharge port 3b for linking the outlet side of the " A plug 4c is installed at the open end of the bore 5 of the modulator block 1 to seal the open end. A discharge passage 4d is formed on the side of the plug 4c, and the discharge passage 4d communicates between the discharge port 3b and the outlet valve 8.

On the other hand, the outlet valve 8 has a spherical body 8a interposed between the valve seat 4b and the plug 4c having an open central portion and the valve seat 4b and the plug 4c. Include.

In the tubular shape, the inner surface is in contact with the piston 6 and the outer surface is guide member 4a installed in the bore 5 to guide the piston 6 to move smoothly. The end of the guide member 4a is engaged with the plug 4c.

The conventional pump 10 configured as described above is assembled after the guide member 4a and the valve seat 4b are separately manufactured, and the discharge flow path 4d must be formed on the plug 4c, thereby increasing the number of parts and complicated assembly process. There was a problem that the productivity is reduced accordingly.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a pump for an anti-lock brake system which reduces the number of parts and simplifies the assembly process by improving the structure of the guide member and the valve seat.

The pump for the anti-lock brake system according to the present invention for achieving the above object is installed in the bore formed in the modulator block to perform a linear reciprocating motion by the rotation axis of the motor, and a piston having a suction flow path therein is provided in the piston. An inlet valve for opening and closing a pump for an anti-lock brake system including a plug provided at an open end of the bore and having an outlet valve for forming a pressurizing chamber between the piston end, the pump for guiding the piston It is installed on the inner surface of the bore to surround the piston, characterized in that it comprises a guide member formed integrally with the valve seat portion forming the outlet valve between the end and the plug.

In addition, between the valve seat portion of the guide member and the plug is characterized in that the discharge passage for communicating with the outlet valve and the outside is formed.

In addition, the discharge passage is characterized in that the orifice is formed.

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

Figure 2 is a hydraulic system diagram of the anti-lock brake system according to the invention and Figure 3 is a cross-sectional view showing a pump for an anti-lock brake system according to the present invention.

2, the anti-lock brake system 30 to which the present invention is applied includes a plurality of solenoid valves 33A and 33B for controlling braking hydraulic pressure transmission to the hydraulic brake 23 side installed on the front wheel and the rear wheel, The low pressure accumulator 34 which temporarily stores the oil escaping from the hydraulic brake 23 side during the decompression braking operation, and a pair of pumps 40L for pumping the oil stored in the low pressure accumulator 34 during the boost / hold braking operation. 40R, the motor 35 for simultaneously driving the pair of pumps 40L and 40R, and the outlet for reducing pressure pulsation of oil pressurized and discharged by driving the pumps 40L and 40R. It has a high pressure accumulator 36 having an orifice 36a disposed on the side, and these components are compactly embedded in a rectangular parallelepiped modulator block 31 made of aluminum.

The plurality of solenoid valves are connected to the upstream side of the hydraulic brake 23 and are normally connected to the NO type solenoid valve 33A and the downstream side of the hydraulic brake 23 and are normally closed. It is distinguished by the NC type solenoid valve 33B which is maintained. 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 according to the depressurizing braking action so that the oil exiting from the hydraulic brake 23 side is temporarily stored in the low pressure accumulator 34.

In addition, the pair of pumps 40L and 40R are driven by a single motor 35 with a certain phase difference to pressurize oil stored in the low pressure accumulator 34 to pump the high pressure accumulator 36. The structure will be described with reference to FIG. 3 as follows. (Because the pair of pumps 40L and 40R are symmetrical with respect to the rotation axis 35a of the motor 35, only one pump structure is enlarged in FIG. 3.)

First, a motor 35 provided with a rotating shaft 35a is installed at one side central portion of the modulator block 31 to drive the pumps 40L and 40R. The tip of the rotating shaft 35a of the motor 35 is composed of an eccentric portion 35b, which is disposed between the pistons 41 of the respective pumps 40L and 40R, so that the pair of pumps 40L and 40R are 180. It is driven with the phase difference of degree.

In order to install the pumps 40L and 40R, such a modulator block 31 has a bore 31a whose both ends are opened in the transverse direction, on the center of the bore 31a and the low pressure accumulator 34 side. The suction port 31b for communicating, the discharge port 31c for communicating the open end side of the bore 31a, and the high pressure accumulator 36 side, etc. are processed.

In addition, the pumps 40L and 40R are slidably installed in the bore 31a, and the piston 41 has a suction passage 41a formed therein in the axial direction and is installed on the surface of the bore 31a. A guide member 47 for guiding the piston 41, an inlet valve 42 provided at the distal end of the piston 41 to open and close the outlet side of the suction passage 41a, and an open end of the bore 31a. It is coupled to form a pressurizing chamber 43 between the piston 41 and the outlet 44 is provided with a plug 44 to prevent the back flow of oil.

The piston 41 is disposed in contact with the eccentric portion 35b of the motor 35 to operate the inlet valve 42 and the outlet valve 45 in opposite directions by linearly reciprocating the inside of the bore 31a. A cylindrical guide member 47 is fitted to the wall of the bore 31a so as to be made smoothly, and a sealing member 49 for preventing the occurrence of leakage is arranged on the outer circumferential surface of the piston 41. The valve seat portion 47a is integrally formed at the end of the bore 31a opening portion of the guide member 47. In addition, the suction passage 41a of the piston 41 is connected with the low pressure accumulator 34 through the suction port 31b, and the discharge side of the pressure chamber 43 discharges with the discharge passage 44a formed in the plug 44. It is associated with the high pressure accumulator 36 via the port 31c.

The inlet valve 42 is provided with a sphere 42a disposed at the outlet end of the suction passage 41a of the piston 41, an elastic member 42c and a retainer 42b that elastically supports the sphere 42a. At this time, the retainer 42b is press-fitted to the outlet end side of the suction passage 41a in a state in which the sphere 42a and the elastic member 42c are accommodated, thereby preventing their separation.

In addition, the outlet valve 45 operates opposite to the inlet valve 42 according to the position of the piston 41 to open and close the discharge passage 44a to be described later, and the valve seat portion having the first orifice 47b formed at the center thereof. 47a and a sphere 45a supported by the elastic member 45c so as to contact the first orifice 47b of the valve seat portion 47a. The elastic member 45c and the sphere 45a of this outlet valve 45 are provided between the guide member 47 and the plug 44 in which the valve seat part 47a was formed. The outer side of the valve seat portion 47a is in contact with the plug 44 and a discharge passage 44a is formed between the valve seat portion 47a and the plug 44. The discharge passage 44a is not formed separately on the side after the plug 44 is manufactured, but the valve seat portion 47a and the plug 44 are formed so that a groove is formed in the first place, and then the valve seat portion 47a and the plug ( If only 44 is assembled, a discharge passage 44a is formed between the valve seat portion 47a and the plug 44. A part of the discharge flow path 44a is formed of the second orifice 45b in which the width of the flow path decreases rapidly. Reference numeral 46 denotes a return spring provided between the tip of the piston 41 and the valve seat portion 47a, that is, in the pressure chamber 43 to support the piston 41 in the bottom dead center direction (arrow B direction).

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

Since the anti-lock brake system is controlled by mixing the three modes of braking pressure reduction, boosting, and holding to prevent slippage of the vehicle, each solenoid valve 33A, 33B is operated with the driving of the pumps 40L, 40R. The opening and closing operation is repeatedly performed to control the hydraulic pressure transmission to the brake 23 side. That is, when the driver presses on the brake pedal 20 (see FIG. 2), the braking force is exerted by the braking hydraulic pressure formed through the boosting device 21 (see FIG. 2) and the master cylinder assembly 22 (see FIG. 2). If the braking pressure in the brake 23 is greater than the road surface condition, the brake pressure should be lowered to an appropriate pressure. In the ECU 32, the NO solenoid valve 33A is closed and the NC solenoid valve 33B is opened.

And if the braking pressure decompression state lasts a long time 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 vehicle tire and the road surface is increased, thereby reducing the vehicle braking efficiency. The ECU 32 determines this situation on the basis of the signals input from each wheel sensor 24, and pumps 40L and 40R through the motor 35 to increase the braking pressure in the hydraulic brake 23. Drive it. Therefore, the oil stored in the low pressure accumulator 34 is pressurized and supplied to the high pressure accumulator 36, and the power is continuously supplied to the hydraulic brake 23 through the NO type solenoid valve 33A which is opened and operated. This increases the braking hydraulic pressure.

The oil stored in the low pressure accumulator 34 is pressurized by the driving of the pumps 40L and 40R and is supplied to the NO type solenoid valve 33A while passing through the high pressure accumulator 36 and the orifice 36a. If only the pump 40L (40R) drive according to the present invention will be described in more detail as follows.

That is, when the piston 41 slides similarly along the guide member 47 as the rotating shaft 35a of the motor 35 rotates in one direction (arrow B direction), the oil pressure in the pressure chamber 43 The inlet valve 42 is closed and the outlet valve 45 is opened, whereby the oil is pumped toward the high pressure accumulator 36 through the discharge passage 44a and the discharge port 31c.

On the other hand, when the piston 41 slides to the bottom dead center along the guide member 47 by the reaction force of the return spring 46 (arrow A direction), the pressurizing chamber 43 becomes a low pressure state, thereby inlet The valve 42 is opened and the outlet valve 45 is closed. Accordingly, the oil on the low pressure accumulator 34 side is sucked into the pressure chamber 43 through the suction port 31b, the suction flow path 41a, and the inlet valve 42.

In this way, the oil supply is controlled by the reciprocating motion of the piston 41 during the control of the antilock brake system.

As described in detail above, in the present invention, the valve seat part is integrally formed in the guide member, and a discharge flow path is formed between the guide member and the plug, so that the number of parts is reduced and the assembly process is shortened, thereby reducing production time and cost. It works.

1 is a cross-sectional view showing a conventional pump for an anti-lock brake system.

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

3 is a sectional view showing a pump for an antilock brake system according to the present invention.

Explanation of symbols on the main parts of the drawings

31: modulator block, 31a: bore,

34: low pressure accumulator, 35: motor,

36: high pressure accumulator, 40L, 40R: pump,

41: piston, 42: inlet valve,

43: pressure chamber, 44: plug,

45: outlet valve, 45b: orifice,

47: guide member, 47a: valve seat portion.

Claims (3)

An inlet valve installed in the bore formed in the modulator block and performing a linear reciprocating motion by a rotational axis of the motor, and having a suction flow path formed therein, which is installed at an open end of the bore and opening the suction flow path. A pump for an anti-lock brake system comprising a plug having an outlet valve for forming a pressure chamber therebetween, It is installed on the inner surface of the bore to guide the piston to guide the piston, one end of the anti-lock brake, characterized in that it comprises a guide member integrally formed with the valve seat portion forming the outlet valve between the plug and the plug. Pump for the system. The method of claim 1, And a discharge flow passage communicating with the outlet valve and the outside is formed between the valve seat portion of the guide member and the plug. The method of claim 2, And an orifice is formed in the discharge passage.