KR20020069784A - Hydraulic pump for anti-lock brake system - Google Patents

Abstract

PURPOSE: A hydraulic pump for an ABS is provided to reduce a pulsating pressure of a pump and a volume of a modulator block, and to manufacture easily a modulator blocks by forming a damping space instead of a high pressure accumulator at a discharge side of a pump. CONSTITUTION: A hydraulic pump for an ABS(Anti-Lock Break System) comprises a compression space(41), a piston(42), a cup type first plug(43), an orifice(47), a second check valve(48), a second plug(44), a sealing member(51), and a through passing hole(49). The compression space is formed into a modulator, an intake port is provided at one side of the compression space, and a discharging port is provided at the other side thereof. The piston is formed at the compression space. The first plug is formed in the compression space divided into the piston side and the discharge side. The second check valve is provided to prevent oil drained to the discharging port from flowing reversely. An inside of the second plug is separated remotely from an outside of the first plug to form a damping space for reducing a pulsating pressure. The sealing member is installed slidably between the outside of the first plug and the inside of the second plug.

Description

HYDRAULIC PUMP FOR ANTI-LOCK BRAKE SYSTEM}

The present invention relates to a hydraulic pump for an antilock brake system, and more particularly, to a hydraulic pump for an antilock brake system provided with a damping device for reducing pressure pulsation of oil on the discharge side of the hydraulic pump.

The ANTI-LOCK BRAKE SYSTEM (hereinafter referred to as ABS) mounted on the vehicle intercepts the braking hydraulic pressure transmitted to the wheel side of the vehicle to prevent road slippage of the wheel to ensure safe braking. Device.

1 is a hydraulic circuit diagram configured in a modulator block of a vehicle ABS. Referring to this, in the modulator block 10 of the conventional vehicle ABS, a plurality of solenoid valves (11a, 11b) for opening and closing the flow path formed therein, the motor 13 and the hydraulic pump (14) for repressurizing the returning oil, A low pressure accumulator 12 and a high pressure accumulator 15 are disposed on the upstream and downstream flow paths of the hydraulic pump 14, respectively. And these devices are interconnected through a plurality of flow paths formed in the modulator block 10, the operation is controlled by an electronic control unit (not shown, ELECTRIC CONTROL UNIT), respectively, wheel wheel cylinder from the master cylinder (16) It functions to control the braking hydraulic pressure delivered to the 17. That is, the electronic control unit (not shown) controls a plurality of solenoid valves (11a, 11b) to open and close the flow path at the same time, the hydraulic pump The brake oil returned to the low pressure accumulator 12 along the hydraulic line by the driving of the 14 is re-pressurized by the wheel-side wheel cylinder 17 so that intermittent braking of the wheel is achieved.

Here, the low pressure accumulator 12 disposed in the upstream flow passage of the hydraulic pump 14 functions to cause the brake oil returning from the wheel side to be temporarily stored and then supplied to the hydraulic pump 14. In addition, the high pressure accumulator 15 disposed in the downstream flow path of the hydraulic pump 14 serves to attenuate the pressure pulsation caused by the operation of the hydraulic pump 14 while temporarily storing the oil pressurized by the hydraulic pump 14. .

However, since the conventional ABS for the vehicle has to provide an oil accommodation space separately in the modulator block 10 in order to configure the high-pressure accumulator 15, the volume of the modulator block 10 is increased, and the processing and oil processing of the oil accommodation space are performed. Due to the installation work of various components mounted in the receiving space, etc., there was a problem that the production of the modulator block 10 was difficult.

The present invention is to solve the above problems, an object of the present invention is to provide a damping space for performing the function of the conventional high-pressure accumulator on the discharge side of the hydraulic pump not only to reduce the volume of the modulator block but also to manufacture the modulator block It is to provide a hydraulic pump for the anti-lock brake system to facilitate.

1 is a hydraulic system showing a configuration of a conventional anti-lock brake system.

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

3 is a cross-sectional view showing the configuration of the hydraulic pump for the anti-lock brake system according to the present invention.

4 and 5 show the operation of the hydraulic pump to detail 'A' of FIG.

Explanation of symbols on the main parts of the drawings

20: master cylinder, 21: wheel cylinder,

30, 31: solenoid valve, 32: low pressure accumulator,

33: motor, 40: hydraulic pump,

41: compression chamber, 42: piston,

43: first plug, 44: second plug,

45: first check valve, 46: restoring spring,

47: orifice, 48: second check valve,

49: communication hole, 50: damping space,

51: sealing member, 100: modulator block.

Hydraulic pump for the anti-lock brake system according to the present invention for achieving the above object, the compression chamber is formed in the modulator block, the suction port is provided on one side and the discharge port is provided on the other side, and is installed to be retractable inside the compression chamber Both ends of the flow path formed at the center thereof are connected to the suction port and the discharge port, respectively, and a piston provided with a first check valve for preventing a backflow on one side of the flow path, and the compression chamber is provided with the piston and the discharge port. A cup-shaped first plug which is installed into the compression chamber so as to be partitioned toward the side, an orifice formed around the first plug to allow the discharge port to communicate with the inside of the first plug, and to control the discharge pressure; And a second body provided in the first plug to prevent backflow of oil discharged toward the discharge port. A valve is provided to enter the opening of the compression chamber so as to close the opening of the compression chamber in communication with the outside of the modulator block and cover a portion of the outer surface of the first plug. The second plug is installed so that the inner surface is spaced apart from the outer surface of the first plug, and a predetermined section can be slid between the outer surface of the first plug and the inner surface of the second plug so that the discharge port side and the damping space are partitioned. And a communicating hole formed in the first plug so as to communicate with the inside of the first plug.

In addition, the compression chamber is configured in a multi-stage type in which the inner diameter gradually increases from the side in which the piston is installed to the side in which the second plug is installed, the discharge port is characterized in that provided in a position corresponding to the outer surface of the first plug. .

In addition, the first plug is provided in a multi-stage type in which the outer diameter decreases toward the second plug from the piston side, and the inner surface of the second plug corresponds to the outer shape of the first plug in a state spaced apart from the outer surface of the first plug. Characterized in that the shape is provided.

And the sealing member is provided with an elastic rubber material, characterized in that the O-ring (O-ring) having a circular cross section.

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

In the vehicle anti-lock brake system ABS to which the present invention is applied, as illustrated in FIG. 2, the braking hydraulic pressure formed in the master cylinder 20 is transmitted to the wheel cylinders 21 installed on the front and rear wheels of the vehicle, respectively. (Iii) a plurality of solenoid valves 30 and 31 for controlling, a pair of low pressure accumulators 32 for temporarily storing oil returning from the wheel cylinder 21 side, and stored in the low pressure accumulator 32; A pair of hydraulic pump 40 for pressurizing and recirculating oil is provided. And all these devices are compactly embedded in a cuboid-shaped modulator block 100 made of aluminum (AL) material, a plurality of flow paths are formed in the modulator block 100 to interconnect them.

The solenoid valves 30 and 31 are disposed in an upstream flow path of the wheel cylinder 21 and are normally open solenoid valves 30 (hereinafter referred to as "NO-type solenoid valves") that are normally kept open, and the wheel cylinders 21. And a normally closed solenoid valve (31, hereinafter referred to as an "NC solenoid valve") disposed on the downstream side of the < RTI ID = 0.0 > At this time, the opening and closing operation of the solenoid valve (30, 31) by the electronic control unit 24 for detecting the vehicle speed through the wheel sensor 22 disposed on the front wheel (FR) (FL) and the rear wheel (RR) (RL). Each controlled.

The low pressure accumulator 32 is disposed in the flow path connecting the downstream side of the NC type solenoid valve 31 and the pump 40 so that when the pressure of the wheel cylinder 21 is reduced, the NC type solenoid valve 31 is opened. It serves to temporarily store oil returning from the wheel cylinder 21.

And the hydraulic pump 40 is composed of a pair of both sides are driven at the same time by a constant phase difference by the motor 33 to supply the oil stored in the low pressure accumulator 32 back to the upstream side of the NO-type solenoid valve 30 Function

The ABS hydraulic pump 40 according to the present invention has a damping space to reduce the pressure pulsation of the pump on the discharge side to replace the function of the high-pressure accumulator provided in the conventional modulator block for ABS can exhibit a smooth braking performance. At the same time, the overall volume of the modulator block can be reduced. Hereinafter, the configuration of the hydraulic pump 40 will be described in detail.

Referring to FIG. 3, the hydraulic pump 40 is press-fitted to the compression chamber 41 formed in the modulator block 100, the piston 42 installed in the compression chamber 41 so as to move forward and backward, and the compression chamber 41. And a first plug 43 and a second plug 44.

The compression chamber 41 is formed long through the cutting process so that the outer surface of the modulator block 100 communicates with the space in which the cam 35 coupled to the rotational shaft 33a of the motor 33 is installed. At this time, the compression chamber 41 has a structure in which the outer diameter gradually expands toward the opening from the center of the modulator block 100 where the piston 42 is installed, and the small diameter portion 41a for the installation of the piston 42. And a middle neck portion 41b for installing the first plug 43 and a large neck portion 41c for installing the second plug 44. In addition, a suction port 36 connected to the low pressure accumulator 32 side is formed at one side of the small diameter portion 41a of the compression chamber 41, and a NO type solenoid valve (1) at one side of the middle diameter portion 41b of the compression chamber 41. A discharge port 37 is formed which is associated with the upstream side flow path 30.

The piston 42 is installed in the small diameter portion 41a of the compression chamber 41 so as to be able to advance and retract so that one end contacts the cam 35 which rotates eccentrically by the driving of the motor 33. In addition, a flow path 42a is formed in the center of the piston 42 in the longitudinal direction so that the suction port 36 and the discharge port 37 of the compression chamber 41 can be connected to each other, and at the outlet side of the flow path 42a, a piston ( A first check valve 45 is installed to prevent oil from flowing back through the flow passage 42a so that the oil is pumped toward the discharge port 37 when the 42 is advanced. At this time, the first check valve 45 has a sphere 45a for opening and closing the outlet of the flow path 41a, a spring 45b for elastically supporting the sphere 45a, and a spring 45b and a sphere 45a for supporting the sphere 45a. The cup retainer 45c fixed to the end of the piston 42 in a state is included.

The first plug 43 is for dividing the inside of the compression chamber 41 into a space in which the piston 42 is installed and a space in which the discharge port 37 is provided. The shape of the first plug 43 is provided in a cup shape and the opening is compressed. After entering the inside of the seal 41, it is press-fitted and fixed. At this time, a restoring spring 46 for restoring the piston 42 is installed inside the first plug 43, and a first check valve 45 coupled to the piston 42 in the inner space of the restoring spring 46. ) Is entered.

In addition, the first plug 43 has a smaller outer diameter than the inner diameter of the compression chamber 41 so that a space for oil flow is formed between the inner surface of the compression chamber 41 and the inner surface of the compression shaft 41. It is formed to have a small diameter portion (43a) of the multi-stage to reduce the outer diameter on the rear side is configured to enter into the second plug 44 to be described later. In addition, an orifice 47 is formed around the first plug 43 to allow oil pumped by the movement of the piston 42 to flow toward the discharge port 37 and communicate with the inside and the outside to adjust the discharge pressure of the oil. Is formed. The inner diameter of the first plug 43 on the side where the orifice 47 is formed is increased toward the second plug 44 so that a second check valve 48 for preventing backflow of oil flowing toward the orifice 47 can be installed. This gradually consists of a multistage type. At this time, the second check valve 48 is pressurized into the first plug 43 having a multi-stage type, and a valve seat 48a having a flow path in the center thereof, a sphere 48b for opening and closing the flow path of the valve seat 48a, And a spring 48c for elastically supporting the sphere 48b.

The second plug 44 is coupled to the large diameter portion 41c of the compression chamber 41 to close the opening of the compression chamber 41 and simultaneously reduce the pressure pulsation of the discharged oil. In order to form a damping space 50 for accommodating oil therebetween. The second plug 44 is provided in a cup shape with one side open, and the outer surface is sized to correspond to the large diameter portion 41c of the compression chamber 41 and is press-fitted to the inner surface of the compression chamber large diameter portion 41c. In addition, the second plug 44 has an inner diameter larger than the outer diameter of the first plug 43 and is formed in a shape substantially corresponding to the outer surface of the first plug 43, and has an inner surface to form a damping space 50. It is installed in a state spaced apart from the outer surface of the first plug 43. In addition, a communication hole 49 is formed at a predetermined diameter so that oil inside the first plug 43 flows into the damping space 50 at the rear end of the small diameter portion 43a of the first plug 43.

In addition, between the outer surface of the small diameter portion 43a of the first plug 43 and the inner surface of the second plug 44, the discharge port 37 and the damping space 50 are partitioned, and at the same time, inside the damping space 50. When the furnace oil is introduced, a sealing member 51 is installed to allow the volume of the damping space 50 to be varied in a predetermined amount. The sealing member 51 is elastic so that the inner surface is in close contact with the outer surface of the small diameter portion 43a of the first plug 43 and the outer surface is in close contact with the inner surface of the second plug 44 while the sliding movement is performed for a predetermined period. It is provided with a rubber material having a circular cross section is made of O-ring (O-ring).

The following describes the overall operation of the ABS to which the hydraulic pump according to the present invention is applied.

When the driver presses the brake pedal, the back pressure is generated by the pressure difference in the power supply device 20a, and the braking hydraulic pressure is formed by receiving this force from the master cylinder 20, and this hydraulic pressure is applied to the NO solenoid valve 30. It is supplied to the wheel cylinder 21 on each wheel side through the braking force.

At this time, when excessive braking pressure is transmitted, the wheel of the vehicle stops rotating and slips on the road surface. This phenomenon is transmitted to the electronic control unit 24 through the wheel sensor 22 mounted on the wheel side of the vehicle. . The electronic control unit 24 opens the NC solenoid valve 31 to allow oil in the wheel cylinder 21 to escape, thereby releasing temporary braking to prevent slippage. This operation is repeatedly controlled by the electronic control unit 24 and stable braking is achieved by applying an intermittent braking pressure to the wheel cylinder 21.

In addition, the oil escaping through the NC type solenoid valve 31 is moved to the low pressure accumulator 32 and stored for a while, and the oil of the low pressure accumulator 32 is pumped by the driving of the hydraulic pump 40, and then again the NO type solenoid valve. It is supplied to the upstream side of 30 to form a braking pressure.

On the other hand, the hydraulic pump 40 according to the present invention is the oil introduced through the suction port 36 while the piston 42 is retracted when the cam 35 eccentrically driven by the drive of the motor 33 is rotated Is forcibly pumped toward the discharge port 37. In this case, the discharged oil is introduced into the damping space 50 of the hydraulic pump 40 and flows to the discharge port 37 through the orifice 47 in a state in which pressure pulsation is reduced.

In more detail, when the piston 42 of the hydraulic pump 40 performs the forward movement toward the damping space 50, as shown in FIG. 4, the first check valve 45 is the piston 42. Since the oil passage 42a is closed, the oil in the compression chamber 41 is supplied to the orifice 47 and the damping space 50 while pushing the sphere 48b of the second check valve 48. That is, at this time, since the second check valve 48 is open, some oil is supplied toward the discharge port 37 through the orifice 47, and the remaining oil is introduced into the damping space 50 through the communication hole 49. Supplied. Therefore, since the pressure increases in the damping space 50, the sealing member 51 may be slightly deformed, and the inner space may be expanded while moving toward the piston 42, thereby reducing the pressure pulsation of the oil.

In addition, when the piston 42 of the hydraulic pump 40 retreats, as shown in FIG. 5, since the first check valve 45 is opened and the second check valve 48 is closed, the suction port is performed. The oil flowing into the 36 flows into the compression chamber 41 through the flow passage 42a of the piston 42. In this case, the oil accumulated in the damping space 50 is supplied to the discharge port 37 through the orifice 47, thereby lowering the internal pressure of the damping space 50 again. The sealing member 51 partitioning the damping space 50 and the discharge port 37 is restored to its original state, and the pressures at both sides of the sealing member 51 are in an equilibrium state. In this case, the pressure in the discharge port 37 and the pressure in the damping space 50 are equal to each other.

As described above, the hydraulic pump 40 according to the present invention can attenuate the pressure pulsation of the pump by repeating the reception and discharge of the oil while the internal volume of the damping space 50 is stretched when the fluid is pumped.

As described in detail above, the hydraulic pump for the anti-lock brake system according to the present invention has an effect of reducing the pressure pulsation of the pump by forming a damping space on the discharge side of the pump instead of the high-pressure accumulator which is provided separately in the conventional modulator block for ABS. While exhibiting, the volume of the modulator block is greatly reduced, and the manufacturing of the modulator block is easy.

Claims (5)

The compression chamber is formed in the modulator block, the suction port is provided on one side and the discharge port is provided on the other side, and is installed to be retractable in the compression chamber, and both ends of the flow path formed at the center thereof are connected to the suction port and the discharge port, respectively. A piston provided with a first check valve for preventing a backflow at one side of the flow path, a cup-type first plug installed into the compression chamber so as to partition the compression chamber toward the piston and the discharge port; An orifice formed around the first plug to allow the inside of the first plug to communicate with the discharge port and to control the discharge pressure, and provided in the first plug to prevent backflow of oil discharged toward the discharge port. Closing the opening of the compression chamber in communication with the second check valve and the outside of the modulator block A second plug having an inner surface spaced apart from an outer surface of the first plug so as to enter a opening of the compression chamber to cover a portion of the outer surface of the first plug and to form a damping space for pressure pulsation reduction of oil; A sealing member slidably disposed between the first plug outer surface and the second plug inner surface such that the discharge port and the damping space are partitioned, and the first damping space communicates with the inside of the first plug. Hydraulic pump for an anti-lock brake system, characterized in that it comprises a communication hole formed in the plug in a predetermined diameter. The method of claim 1, The compression chamber is a hydraulic pump for an anti-lock brake system, characterized in that the inner diameter gradually increases from the side in which the piston is installed to the side in which the second plug is installed. The method of claim 1, The discharge port is a hydraulic pump for an anti-lock brake system, characterized in that provided in a position corresponding to the outer surface of the first plug. The method of claim 1, The first plug is provided in a multi-stage type in which an outer diameter decreases toward the second plug from the piston side, and an inner surface of the second plug corresponds to the outer shape of the first plug in a state spaced apart from the outer surface of the first plug. Hydraulic pump for anti-lock brake system, characterized in that provided in the shape. The method of claim 1, The sealing member is provided with a rubber material having elasticity and the hydraulic pump for the anti-lock brake system, characterized in that the cross-section is an O-ring (O-ring).