Pump for antilock braking system in vehicle

Abstract

An antilock braking system pump having a plurality of intake check valves that are installed perpendicularly in relation to a direction of the linear reciprocating motion of a piston is provided, resulting in a reduction of intake resistance of brake fluid, decrease of the overall size of the pump, and simplification of the structure and assembly thereof.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is based on, and claims priority from, Korean Application Serial Number 10-2004-0019279, filed on Mar. 22, 2004, the disclosure of which is hereby incorporated by reference herein in its entirety.

FIELD OF THE INVENTION

The present invention relates to a pump used in an antilock-braking system (ABS) of a vehicle. More particularly, the present invention relates to a pump installed in an ABS modulator to generate a rapid and intermittent hydraulic brake pressure.

BACKGROUND OF THE INVENTION

Generally, the antilock-braking system (ABS) of a vehicle provides a rapid intermittent hydraulic brake pressure to each wheel for averting wheel lockup by detecting the variation of wheel rotations during braking.

The pump generating the rapid intermittent hydraulic brake pressure is primarily a piston pump installed at the ABS modulator. A cam rotating via a motor repeatedly presses a piston, resiliently supported by a spring, in a short time period interval to thereby generate the intermittent hydraulic pressure.

SUMMARY OF THE INVENTION

Embodiments of the present invention are provided with an antilock-braking system (ABS) pump adapted to reduce the intake resistance of the brake fluid, simplify the structure, and decrease the overall size thereof.

A pump for the antilock-braking system (ABS) comprises a main body. A piston is installed at a portion thereof in the main body to engage in a linear reciprocating motion. A piston spring is installed in the main body in a state of pushing the piston to the exterior of the main body. Intake check valves are configured to take brake fluid into the main body by allowing intake check balls to move in a direction generally perpendicular to the linear reciprocating movement of the piston. An exhaust check valve is configured to exhaust the brake fluid from the main body to the exterior by moving an exhaust check ball in the same direction as the linear reciprocating movement of the piston.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the nature and objects of the present invention, reference should be made to the following detailed description with the accompanying drawings, in which:

FIG. 1 illustrates a pump structure of an antilock-braking system according to an embodiment of the present invention; and

FIG. 2 illustrates another embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, a pump of an antilock-braking system according to an embodiment of the present invention comprises a main body 1. A piston 3 is installed at a portion thereof in the main body 1 to engage in a linear reciprocating motion. A piston spring 5 is installed in the main body 1 in a state of biasing the piston 3 toward the exterior of the main body 1. Intake check valves 9 are configured to take brake fluid into the main body 1 by allowing intake check balls 7 to move in a direction generally perpendicular to the direction of the linear reciprocating movement of the piston 3. An exhaust check valve 13 is configured to exhaust the brake fluid from the main body 1 to the exterior by moving an exhaust check ball 11 in the same direction as the direction of the linear reciprocating movement of the piston 3.

The intake check valves 9 include a fluid intake passage 15, two intake check balls 7, and an intake spring 17. The fluid intake passage 15 is formed to penetrate the main body 1 in a direction generally perpendicular to the direction of the linearly reciprocating movement of the piston 3. The two intake check balls 7 are located at opposite sides of the fluid intake passage 15 in relation to an axis that penetrates the center of the piston 3. The intake spring 17 is positioned between the two intake check balls 7 to apply the resilient force to the two intake check balls 7.

The intake spring 17 is formed in a “C” shape by bending a spring steel plate in the first embodiment of the present invention. With reference to FIG. 2, the intake spring 17 can be substituted by a coil spring according to another embodiment of the present invention.

The intake spring 17 and intake check balls 7 of the intake check valves 9 are disposed perpendicularly to the linear reciprocating movement direction of the piston 3; thus, the pump length regarding the linear reciprocating movement of the piston 3 can be shortened.

The intake spring 17 supports both of the intake check balls 7, thereby reducing the number of required components.

The main body 1 is installed with an insert 19 therein. The insert 19 is placed between the piston spring 5 and exhaust check valve 13. The insert 19 is provided with the intake spring 17, and some portions of the fluid intake passage 15 are formed in the insert 19. The insert 19 is also formed with a fluid exhaust passage 21 that connects a pumping space (S), which is formed by the piston 3, piston spring 5, and main body 1, with the exhaust check valve 13.

The fluid exhaust passage 21 connects with an exhaust hole 22 formed in the main body 1.

The exhaust check ball 11 and exhaust spring 23 constitutes the exhaust check valve 13. The exhaust check ball 11 is located along the axis, passing through the center of the piston 3, and contacts the insert 19. The exhaust spring 23 forcibly presses the exhaust check ball 11 towards the insert 19.

The exhaust check ball 11 configured to contact the insert 19 helps to reduce the length of the pump.

The insert 19 is assembled into the main body 1 with the intake spring 17 and intake check balls 7 provisionally coupled to the insert 19, thus simplifying the pump assembly.

As two intake check valves 9 and one exhaust check valve 13 are used in the embodiment of the present invention, the overall intake cross-sectional area of the brake fluid increases, thereby decreasing the intake resistance occurred when the brake fluid enters into the pump.

The piston 3 is integrally mounted with a stopper 25 having a circular shape configuration and protruding out at the periphery of the piston 3 to restrict the insertion amount of the piston 3 into the main body 1. As shown in FIGS. 1 and 2, the piston 3 is shown in its fully compressed condition, with the stopper 25 engaged with the main body 1.

The operation of the pump thus constructed will now be described.

When a cam (not shown) intermittently presses the piston 3 as the cam rotates, the piston 3 starts to linearly reciprocate in the main body 1 via the piston spring 5 and cam. When the piston 3 is pushed away via the piston spring 5, the intake check valves 9 are opened and the brake fluid enters into the main body 1. If the piston 3 is forcibly inserted into the main body 1 via the cam, the exhaust check valve 13 is opened and the brake fluid discharges from the main body 1.

As apparent from the foregoing, there is an advantage in that a plurality of intake check valves are perpendicularly installed in relation to the direction of the linear reciprocating motion of a piston, thereby reducing intake resistance of the brake fluid, decreasing the overall size of the pump, and simplifying the structure and assembly thereof.

Although the invention has been described with reference to an exemplary embodiment, it is understood that the words that have been used are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the invention has been described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein. Instead, the invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims.

Claims

1. A pump for an antilock-braking system, said pump comprising: a main body; a piston installed at a portion thereof in said main body to engage in a linear reciprocating motion; a piston spring installed in said main body to bias said piston toward the exterior of said main body; a plurality of intake check valves configured to take brake fluid into said main body by allowing intake check balls to move in a direction generally perpendicular to the direction of the linear reciprocating motion of said piston; and an exhaust check valve configured to exhaust brake fluid from said main body to the exterior by moving an exhaust check ball in the same direction as the direction of the linear reciprocating motion of said piston.

2. The pump as defined in claim 1, wherein said intake check valves include: a fluid intake passage that is formed to penetrate said main body in a direction generally perpendicular to the direction of the linear reciprocating motion of said piston; two intake check balls that are located at opposite sides of said fluid intake passage in relation to an axis that penetrates the center of said piston; and an intake spring that is positioned between said two intake check balls to apply a resilient force to said two intake check balls.

3. The pump as defined in claim 2, wherein said intake spring is formed as a spring steel plate having a generally “C” shape.

4. The pump as defined in claim 2, wherein said intake spring is formed as a coil spring.

5. The pump as defined in claim 2, wherein said main body is provided with an insert therein, said insert placed between said piston spring and exhaust check valve, said insert provided with said intake spring, said insert formed to include portions of said fluid intake passage, and said insert formed with a fluid exhaust passage that connects a pumping space, which is formed by said piston, piston spring, and said main body, with said exhaust check valve.

6. The pump as defined in claim 5, wherein said exhaust check valve includes: an exhaust check ball located along the axis passing through the center of said piston, and said exhaust check ball contacting said insert; and an exhaust spring that forcibly biases said exhaust check ball towards said insert.

7. The pump as defined in claim 1, wherein said piston is integrally provided with a stopper having a generally circular configuration and protruding out at the periphery of said piston to restrict an insertion amount of said piston into said main body.