KR20080012650A - Pump for brake system - Google Patents

Abstract

A pump for a brake system is provided to press one surface of a sealing member by using oil of a pressing chamber, so that the sealing member sticks to a guide member. A sealing member(60) has the first side supported by a support step protruding from an outer surface of a piston(33) and the second side supported by a spring support member(44). A suction passage(45) is provided in the piston to communicate with a pressing chamber(41). A discharge passage(46) guides the discharge of oil to the pressing chamber. A valve(47) is installed in the piston such that the suction passage is opened and closed. A discharge valve(50) opens or closes the discharge passage.

Description

Pump for brake system {PUMP FOR BRAKE SYSTEM}

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

2 is a hydraulic circuit diagram of a brake system to which the present invention is applied.

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

4 is an exploded perspective view showing a piston, a sealing member, and an inlet valve of a pump for a brake system according to the present invention.

Explanation of symbols on the main parts of the drawings

30: hydraulic pump 31: housing

32: bore 33: piston

34: motor 40: plug

41: pressure chamber 42: guide member

43: piston spring 44: spring support member

45: suction passage 46: discharge passage

47: inlet valve 50: outlet valve

60: sealing member 61: support jaw

The present invention relates to a pump for a brake system, and more particularly, to a pump for a brake system that can easily install the sealing member on the outside of the piston and to improve the sealing effect of the sealing member.

Conventional brake system pumps pressurize oil and feed it to the wheel cylinder on the wheel side to allow braking of the vehicle. An example of such a pump for a brake system is disclosed in Korean Patent Laid-Open Publication No. 2005-122326.

As shown in FIG. 1, the pump disclosed in the above publication has a piston 3 for pressurizing oil in the pressurizing chamber 2 and a piston to open and close an inlet of the pressurizing chamber 2 while advancing by the operation of the motor 1. An inlet valve (4) mounted at the rear end of (3), a discharge valve (5) for opening and closing the outlet of the pressurizing chamber (2) by a pressure change of the pressurizing chamber (2) as the piston (3) moves forward and backward; A guide member 6 is provided around the piston 3 to guide the advance and retreat of the piston 3 and to define the pressurizing chamber 2.

In addition, a sealing member 7 for sealing is provided between the outer surface of the piston 3 and the inner surface of the guide member 6. In order to install the sealing member 7, an outer surface of the piston 3 is provided with a first supporting jaw 3a and a second supporting jaw 3b protruding toward the inner surface of the guide member 6, and the sealing member 7 is provided. Is accommodated in the groove 3c between the two supporting jaws 3a and 3b. The sealing member 7 is accommodated in the groove 3c between the two supporting jaws 3a and 3b to prevent the sealing member 7 from being separated when the piston 3 moves forward and backward. A supporting member 8 is also provided between the two supporting jaws 3a and 3b to support the sealing member 7 to prevent damage of the sealing member 7.

However, such a brake system pump has to form two support jaws (3a, 3b) on the outer surface of the piston (3) in order to install the sealing member (7), so that the shape of the piston (3) is complicated to process the piston (3) This was a difficult problem. In addition, when the sealing member 7 and the support member 8 are inserted into the grooves 3c between the two support jaws 3a and 3b, they have to overcome one of the two support jaws 3a and 3b, which makes it difficult to assemble. there was.

In addition, when the sealing member 7 is worn out for a long time, the sealing effect between the sealing member 7 and the inner surface of the guide member 6 may be reduced.

The present invention is to solve the above problems, an object of the present invention is to simplify the shape of the piston than the prior art to facilitate the processing of the piston, and to provide a pump for the brake system to easily mount the sealing member To provide.

It is another object of the present invention to provide a pump for a brake system that allows the sealing effect of the sealing member to be improved than before.

A pump for a brake system according to the present invention for achieving this object is a housing in which a bore is formed, a piston installed in the bore to be retractable, and a pressure chamber installed in the bore to guide the retraction of the piston and for pressurizing oil. A guide member defining a piston, a piston spring installed in the pressurizing chamber to pressurize the piston, a spring support member installed on the piston to support the piston spring, and a seal between the piston outer surface and the inner surface of the guide member. It includes a sealing member installed on the piston, the sealing member is characterized in that one side is supported on the support jaw protruding from the piston outer surface and the other side is supported by the spring support member.

In addition, the pump of the present invention, the suction passage formed in the piston to communicate with the pressure chamber, a discharge passage for guiding the discharge of oil from the pressure chamber, an inlet valve installed in the piston for opening and closing the suction passage, and the discharge It further comprises a discharge valve for opening and closing the flow path.

In addition, the sealing member is characterized in that one surface is pressed by the oil of the pressure chamber.

In addition, the spring supporting member includes a cap-shaped body portion coupled to the piston on the outlet side of the suction flow passage, and a flange portion formed at one end of the body portion for supporting the piston spring, wherein the sealing member is formed by the flange portion. It is characterized in that it is supported.

In addition, the inlet valve includes an opening and closing member removably installed in the body portion to open and close the outlet of the suction passage, and a spring installed in the body portion to press the opening and closing member in the direction of closing the outlet of the suction passage. It is characterized by.

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

As shown in FIG. 2, the brake system to which the present invention is applied is installed in the middle of a hydraulic line connected from the master cylinder 10 to the wheel-side wheel cylinder 12 to open and close a flow path and open a normally open state. The first valve 13 to hold | maintain, and the 2nd valve 14 which opens and closes the flow path of the oil returning from a wheel side, and maintains normally closed state (Normal Close). In addition, the hydraulic pump 30 for re-pressurizing the oil returned from the wheel-side wheel cylinder 12 to the upstream flow path of the first valve 13 and the upstream and downstream flow paths of the hydraulic pump 30 are respectively provided and buffered. A low pressure accumulator 16 and a high pressure accumulator 17 forming a space BUFFER are provided.

This brake system allows the second valve 14 to close when the first valve 13 is opened to apply braking pressure to the wheel side, and the second valve 14 to open when the first valve 13 is closed to the wheel side. To release the brake pressure. The low pressure accumulator 16 installed upstream of the hydraulic pump 30 allows the brake oil returning from the wheel side to be temporarily stored and supplied to the hydraulic pump 30, and installed on the downstream side of the hydraulic pump 30. The high pressure accumulator 17 allows the pressure pulsation caused by the operation of the hydraulic pump 30 to be attenuated while the oil pressurized by the hydraulic pump 30 is temporarily stored. Although these devices are not shown in the figure, the operation is controlled by an electronic control unit (ECU). That is, the electronic controller controls the first and second valves 13 and 14 to apply intermittent braking pressure to the wheel side, and controls the driving of the hydraulic pump 30 to control the oil of the low pressure accumulator 16 to the wheel side. To be pressurized.

In addition, the brake system includes a control system for preventing slippage of wheels and road surfaces or stably controlling the running of the vehicle at the time of sudden departure of the vehicle. The control system includes a separate bypass passage 18 connecting the outlet hydraulic line of the master cylinder 10 and the inlet hydraulic line of the hydraulic pump 30, and a third valve for opening and closing the bypass passage 18. 19 and a fourth valve 20 installed in a hydraulic line connecting the outlet side of the master cylinder 10 and the outlet side of the high pressure accumulator 17.

In this control system, the braking pressure generated by the driver's stepping on the brake pedal 11 can be applied to the wheel cylinder 12 of the wheel by keeping the third valve 19 closed and the fourth valve 20 open. Make sure However, when the road slippage of the wheel occurs due to the rapid start of the vehicle or when braking is required for driving stability control of the vehicle, the hydraulic valve 30 is opened with the third valve 19 opened and the fourth valve 20 closed. ) Works. Therefore, even when the driver does not step on the brake pedal 11, the braking pressure generated by the operation of the hydraulic pump 30 is supplied to the wheel cylinder 12 to allow braking. This allows stable starting and running of the vehicle.

The hydraulic pump 30 forming the braking pressure is provided in the housing 31 of the hydraulic unit for implementing the above-mentioned brake system, as shown in FIG.

The hydraulic pump 30 includes a bore 32 formed in the housing 31, a piston 33 installed in the bore 32 in a retractable manner, and a motor 34 for advancing and retracting the piston 33. do. The motor 34 has a rotating shaft 36 with an eccentric 35, which is installed to enter the interior of the housing 31. The eccentric bearing 37 of the rotary shaft 36 is provided with an eccentric bearing 37 which rotates eccentrically by the operation of the rotary shaft 36. And the piston 33 is disposed so that one end is in contact with the outer surface of the eccentric bearing (37). This configuration allows the eccentric bearing 37 to move forward and backward by eccentric rotation by the operation of the motor 34.

The housing 31 has an inlet 38 through which oil is introduced into the bore 32 at one side thereof, and an outlet 39 through which oil is discharged at the other side thereof. Of course, the inlet 38 communicates with the low pressure accumulator 16 flow path of the brake system as shown in FIG. 2, and the outlet 39 communicates with the high pressure accumulator 17 flow path.

The hydraulic pump 30 is installed inside the bore 32 to guide the retraction of the piston 33 and the plug 40 coupled to the housing 31 to close one end of the bore 32 and the plug 40. And a guide member 42 defining a pressurizing chamber 41 for pressurizing the oil, a piston spring 43 installed in the pressurizing chamber 41 for pressurizing the piston 33, and a piston spring 43. It includes a spring support member 44 installed on the piston 33 for the support.

The piston 33 is formed with a suction passage 45 associated with the inlet 38 so that oil can flow into the pressure chamber 41, and the plug 40 has an oil outlet 39 of the pressure chamber 41. A discharge passage 46 is formed in connection with the outlet 39 so as to be discharged. An inlet valve 47 is provided at the outlet of the suction channel 45 of the piston 33 to open and close the suction channel 45 as the piston 33 moves forward and backward, and the plug 40 is moved in and out of the piston 33. As a result, the discharge valve 50 for opening and closing the discharge passage 46 is installed.

Guide member 42 on the outside of the piston 33 is provided in a cylindrical shape and the outer surface is press-fit fixed to the inner surface of the bore (32). Plug 40 has a fixed end (40a) of the rear end is press-fitted to the inlet of the bore 32 and the front end portion (40b) entering the bore 32 is coupled with the guide member 42. And the pressure chamber 41 is limited to the inner region by the coupling of the guide member 42 and the plug 40. Of course, one side of the pressurizing chamber 41 is defined by the piston 33 advancing into the pressurizing chamber 41.

The spring support member 44 has a cap-shaped body portion 44a fixed to the outer surface of one end (outlet side of the suction passage) of the piston 33 and a flange portion 44b formed at one end of the body portion 44a. . One end of the piston spring 43 is supported by the plug 40 and the other end of the piston spring 43 is supported by the flange 44b of the spring support member 44. Accordingly, the piston spring 43 presses the piston 33 toward the rotation shaft 36 of the motor 34 so that the piston 33 moves forward and backward when the motor 34 operates.

The inlet valve 47 opens and closes the opening and closing member 47a installed in the body portion 44b of the spring support member 44 so as to open and close the outlet of the suction passage 45 and the outlet of the suction passage 45. And a spring 47b installed in the body portion 44a of the spring support member 44 to press the opening / closing member 47a in the closing direction. This is because when the piston 33 pressurizes the oil in the pressurizing chamber 41, the outlet of the suction passage 45 is closed by the opening / closing member 47a, and the suction when the piston 33 retreats in the direction of the rotation axis 36. The outlet of the flow path 45 is to be opened. This is a conventional check valve type.

The discharge valve 50 is press-fitted to the ball receiving space 51 and the ball receiving space 51 inlet side formed in communication with the discharge passage 46 in the plug 40, the valve seat 52 formed with an orifice 52a at the center thereof. ), The opening and closing ball 53 installed in the ball receiving space 51 to open and close the orifice (52a) of the valve seat 52, the ball receiving space to press the opening and closing ball 53 toward the valve seat 52 And a spring 54 installed in the 51. The discharge valve 50 has an orifice as the piston 33 enters the pressure chamber 41 and the opening / closing ball 53 is pushed by the pressure of the pressure chamber 41 when the pressure in the pressure chamber 41 rises. The opening and closing ball 53 is opened by the elasticity of the spring 54 when the piston 52 is retracted toward the rotary shaft 36 and the pressure in the pressure chamber 41 is lowered. The discharge passage 46 is closed by closing the orifice 52a of the seat 52. This discharge valve 50 is also a conventional check valve form.

3 and 4, a sealing member 60 for sealing is installed between the outer surface of the piston 33 and the inner surface of the guide member 42. In addition, a support jaw 61 protruding outward from the piston 33 is provided on the outer surface of the piston 33 so as to support the sealing member 60 when the piston 33 advances toward the pressure chamber 41.

The sealing member 60 is made of rubber or silicone having elasticity or a resin material that can be deformed, and is provided in a ring shape so as to be fitted to an outer surface of the piston 33. And the sealing member 60 is supported by the flange 44b of the spring support member 44, one side is supported by the support jaw 61 of the piston 33 and the other side is coupled to the piston 33. That is, the sealing member 60 is supported by the support jaw 61 of the piston 33 and the flange 44b of the spring support member 44 so that the sealing member 60 is separated from the piston 33 when the piston 33 operates. I never do that.

This configuration is to facilitate the processing of the piston 33 by simplifying the appearance of the piston 33 than in the prior art. That is, in the conventional pump, since both sides of the sealing member are supported by two supporting jaws protruding from the piston, the piston has a complicated shape, but in the present invention, only one side of the sealing member 60 protrudes from the piston 33. Since the support jaw 61 is supported, the shape of the piston 33 can be simplified. Therefore, the piston 33 can be easily processed.

This configuration can also facilitate the assembly of the sealing member 60 because the sealing member 60 is supported by the flange 44b of the spring support member 44. That is, according to the present invention, when assembling the sealing member 60, the sealing member 60 may be inserted into the outer surface of the piston 33, and then the spring supporting member 44 may be coupled to the outer surface of the piston 33. ) Can be easily assembled. This is possible because there is no jaw on the outer surface of the piston 33 to which the sealing member 60 is assembled.

In addition, such a sealing member (60) mounting structure has one surface (the side supported by the flange of the spring support member) of the pressing chamber (41) when the piston (33) is advanced toward the pressing chamber (41). Since it can be pressurized by oil, the sealing effect can be improved than before. That is, in the present invention, when the piston 33 is advanced toward the pressure chamber 41, the sealing member 60 is deformed to be in close contact with the inner side of the guide member 42 at the same time as the sealing member 60 is brought into close contact with the support jaw 61 by the pressing force of oil. The sealing effect by the sealing member 60 is improved than before.

In addition, the sealing member 60 installation structure is sealed because the sealing member 60 can be in close contact with the inner surface of the guide member 42 by the pressure of oil even when the sealing member 60 is worn out by using the pump for a long time. The effect can be maintained for a long time. Therefore, the durability of the pump 30 can be improved by that much. Reference numeral 70 in FIG. 3 denotes another sealing member fixed to the inner surface of the bore 32 to seal between the inner surface of the bore 32 and the outer surface of the piston 33.

The following describes the operation of the pump for such a brake system.

As shown in FIG. 3, when the piston 33 moves forward (toward the arrow A) toward the pressure chamber 41 by the operation of the motor 34, the pressure in the pressure chamber 41 rises, so that the inlet valve ( 47 is closed and the discharge valve 50 is opened. Therefore, at this time, the oil in the pressurizing chamber 41 is discharged to the outlet 39 through the discharge passage 46.

On the contrary, when the piston 33 retracts from the pressure chamber 41 by the reaction force of the piston spring 43 (arrow B direction), the pressure in the pressure chamber 41 decreases, so that the inlet valve 47 opens and the discharge valve. 50 is closed. Therefore, at this time, the oil flows into the pressure chamber 41 through the suction passage 45.

As such, the pump 30 changes the volume of the pressurizing chamber 41 as the piston 33 moves in and out to open and close the inlet valve 47 and the discharge valve 50 in opposition to the oil at the inlet 39. It can be suctioned and discharged to the outlet 39.

As described in detail above, the brake system pump according to the present invention is one of the sealing member installed on the outer surface of the piston is supported by the support jaw of the piston and the other side of the sealing member is supported by the spring support member Therefore, the external shape of the piston can be simplified. Therefore, there is an advantage that the machining of the piston can be easily performed.

In addition, in the present invention, since the sealing member is supported by the flange of the spring support member, when assembling the sealing member, it is only necessary to assemble the spring support member to the piston after fitting the sealing member to the outer surface of the piston, so that the sealing member can be easily mounted. It works.

In addition, the present invention has the advantage that the sealing effect of the sealing member is improved compared to the prior art because one surface of the sealing member is pressed by the oil in the pressure chamber can be in close contact with the inner surface of the guide member.

Claims (5)

A housing having a bore formed therein, a piston installed in the bore to move back and forth, a guide member disposed in the bore for guiding the piston forward and backward, defining a pressure chamber for pressurizing oil, and the pressure chamber for pressurizing the piston. In a pump for a brake system comprising a piston spring installed therein, a spring supporting member provided on the piston for supporting the piston spring, and a sealing member provided on the piston for sealing between the piston outer surface and the inner surface of the guide member. , The sealing member is a pump for a brake system, characterized in that one side is supported by the support jaw protruding from the piston outer surface and the other side is supported by the spring support member. The method of claim 1, A suction passage formed in the piston so as to communicate with the pressure chamber, a discharge passage for guiding the discharge of oil from the pressurizing chamber, an inlet valve installed at the piston for opening and closing the suction passage, and a discharge valve for opening and closing the discharge passage. Brake system pump, characterized in that it further comprises. The method according to claim 1 or 2, The sealing member pump for the brake system, characterized in that one surface is pressurized by the oil of the pressure chamber. The method of claim 2, The spring support member includes a cap-shaped body portion coupled to the piston on the outlet side of the suction flow passage, and a flange portion formed at one end of the body portion to support the piston spring, and the sealing member is supported by the flange portion. Pump for brake system, characterized in that the. The method of claim 4, wherein The inlet valve includes an opening and closing member removably installed in the body portion to open and close the outlet of the suction passage, and a spring installed in the body portion to press the opening and closing member in the direction of closing the outlet of the suction passage. Pump for brake system characterized in that.

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