Valve of a piston pump with a closing body

Abstract

A valve of a piston pump, in particular for a hydraulic vehicle brake system, includes a closing body configured to be moved in an axially guided manner against a sealing seat. The closing body is formed in two pieces, which include a damping piston and a closing element inserted in the damping piston.

Claims

1. A valve of a piston pump, comprising: a sealing seat; and a closing body configured to be moved in an axially guided manner against the sealing seat, wherein the closing body is formed in two pieces, the pieces including a damping piston and a closing element inserted therein, wherein the closing element is held on the damping piston such that the closing element is radially translatable within a radial spacing formed between a shaft of the closing element and the damping piston; wherein, on the an end of the damping piston facing towards the closing element, at least one channel is formed through which an underflow, directed radially from outside to inside, of the closing element is possible; and wherein the at least one channel forms a segment of a flow connection through the damping piston to its other end.

2. A valve of a piston pump, comprising: a sealing seat; and a closing body configured to be moved in an axially guided manner against the sealing seat, the closing body formed in two pieces, including: a damping piston having a first end and a second end arranged opposite the first end; and a closing element inserted within the damping piston, wherein the damping piston includes a flow passage through the first end and the second end, wherein the damping piston includes at least one channel through which an underflow, directed radially from outside to inside, of the closing element is possible, and wherein the flow passage is in fluid communication with the at least one channel.

3. The valve as claimed in claim 2, wherein: the at least one channel is formed on the first end of the damping piston.

4. The valve as claimed in claim 3, wherein the at least one channel forms a segment of the flow passage.

5. The valve as claimed in claim 3, wherein a constriction is formed in the at least one channel, the constriction forming a choke.

6. The valve as claimed in claim 5, wherein: the at least one channel is formed by a radially oriented groove formed in the damping piston, and an opening cross section of the groove is reduced in an axial direction at one point.

7. A piston pump of a vehicle brake system, comprising: a valve including: a sealing seat; and a closing body configured to be moved in an axially guided manner against the sealing seat, wherein the closing body is formed in two pieces, the pieces including a damping piston and a closing element inserted therein, wherein the closing element is held on the damping piston such that the closing element is radially translatable within a radial spacing formed between a shaft of the closing element and the damping piston; wherein: at least one channel is formed on an end of the damping piston facing towards the closing element, and an underflow, directed radially from outside to inside, of the closing element is possible through the at least one channel; and wherein the at least one channel forms a segment of a flow connection through the damping piston to its other end.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) An embodiment example of the solution according to the disclosure is explained in more detail below with reference to the enclosed schematic drawings, in which

(2) FIG. 1 shows a partial longitudinal section of a piston pump according to the prior art;

(3) FIG. 2 shows the view according to FIG. 1 of a first embodiment example of a piston pump according to the disclosure with an associated closing body;

(4) FIG. 3 shows a perspective view of the closing body according to FIG. 2;

(5) FIG. 4 shows the view according to FIG. 1 of a second embodiment example of a piston pump according to the disclosure with an associated closing body, and

(6) FIG. 5 shows a perspective view of the closing body according to FIG. 4.

DETAILED DESCRIPTION

(7) FIG. 1 shows a piston pump 10 according to the prior art for a hydraulic vehicle brake system (not shown further) which serves to generate a fluid pressure of brake fluid within the vehicle brake system. The piston pump 10 for this comprises a beaker-shaped cylinder 12 in which a piston (not shown) is mounted displaceably against a coil spring 14. The piston delivers brake fluid through a circular outflow opening 16 formed in the base region of the cylinder 12. The outflow opening 16 is surrounded by a valve seat or sealing seat 18 which is part of an outlet valve 20. The outlet valve 20 furthermore comprises a one-piece dome-like closing body 22, which is pressed by means of a coil spring 24 against the sealing seat 18. The coil spring 24 is supported on a pump cover 26 which surrounds the cylinder 12 on its end.

(8) FIGS. 2 and 3 show a first embodiment example of a piston pump 10 according to the disclosure in which the outlet valve 20 is formed with a two-piece closing body 28. The closing body 28 comprises a damping piston 30 and a mushroom-shaped closing element 32 inserted therein.

(9) Thus a construction is created with which production dimension tolerances, in particular between the sealing seat 18 and the closing body 28, can be compensated in the radial direction. The closing element 32 with its shaft-side end lies on the face of the damping piston 30 and is radially slightly mobile. The closing element 32 comprises a head 34 lying in such a way and also and a shaft 36 inserted into and protruding into the damping piston 30.

(10) The closing element 32 with its shaft 36 has been inserted in a central passage opening 38 formed in the damping piston 30, and has a central depression 40 at its head 34 on the end facing towards the sealing seat 18. This central depression 40 creates a build-up effect for the inflowing fluid and leads to an improved opening behavior of the outlet valve 20.

(11) The closing element 32 is retained on the damping piston 30 by means of a catch, which in the embodiment example shown in FIGS. 2 and 3 is formed by a peripheral shoulder 42 formed on the free end of the shaft 36. The diameter of the shoulder 42 is slightly greater than the diameter of the passage opening 38. The remaining shaft 36 has a slightly smaller diameter than the passage opening 38. The closing element 32 is thus held on the damping piston 30 with radial play, which in particular is guaranteed by the radial spacing of the shaft 36 from the surrounding damping piston 30.

(12) On the end 44 of the damping piston 30 facing the closing element 32 is formed a radially oriented channel 46 through which fluid can flow below the head 34 into the interior of the damping piston 30 and to its rear. This fluid contributes to a damping of the movement of the damping piston 30 which can be adjusted in a targeted manner for different operating pressures. The damping piston 30 is here also spring-pretensioned at its rear by means of a coil spring 24 which rests on a pump cover 26.

(13) In the channel 46 is formed a constriction 48 which forms a choke. This choke brakes the outflow of fluid into the interior of the damping piston 30 in a targeted manner.

(14) To insert the closing element 32 by means of its shaft 36 in the passage opening 38, a chamfer 50 and 52 is formed both on the free end of the shaft 36 and on the face edge of the passage opening 38.

(15) FIGS. 4 and 5 show an embodiment example of a two-piece closing body 28 according to the disclosure in which the catch between the damping piston 30 and the mushroom-shaped closing element 32 is produced by means of studs 54. The studs 54 are distributed over the periphery of the associated shaft 36 at regular intervals where the shoulder 42 is formed in the embodiment example according to FIGS. 2 and 3.