Check valve assembly for a hydraulic power unit

Abstract

Check valve assembly (1) for a hydraulic unit of a motor vehicle brake system, comprising a valve sleeve (2) by means of which the check valve assembly (1) can be inserted into a receiving opening of a receiving body of the hydraulic unit, wherein the valve sleeve (2) comprises a valve seat (6) on which a closing element (3) seals due to a spring force applied by a compression spring (7), wherein the compression spring (7) is supported on one side by a spring retaining element (5) and on the other side presses on the closing element (3), wherein the spring retaining element (5) is connected to the valve sleeve (2) by means of a snap connection.

Description

[0001] Hydraulic power units for motor vehicle braking systems are available in a wide variety of designs. Essentially, a hydraulic power unit comprises a central housing that serves as a valve block and simultaneously incorporates a delivery device, which is either a reciprocating pump or a linear piston compressor. The hydraulic fluid for the motor vehicle braking system is stored in a reservoir located on the valve block. A check valve (also called a filling valve) is typically installed upstream of the delivery device to supply it with hydraulic fluid from the reservoir.

[0002] The check valve is typically designed as a valve assembly that is inserted into a receiving bore of the receiving body and is differentially pressure controlled. The differentially pressure-controlled check valve is closed in its rest position, i.e., in a closed position, and opens when a vacuum is applied, allowing the hydraulic fluid to flow into the pressure chamber of the pumping device. Such a valve assembly usually comprises a valve body in which a closing element, biased by a closing spring, interacts with a valve seat. A disadvantage of conventional valve assemblies, however, is that they have a large number of components and joining or assembly steps, resulting in complex manufacturing, high overall production costs, and a high susceptibility to malfunctions. Such a valve assembly can be found, for example, in DE 102 34 541 A1.

[0003] The object of the invention is to provide a check valve assembly for a hydraulic unit of a motor vehicle brake system which is simplified in design, has a small number of individual parts and requires few assembly steps in manufacturing, but at the same time exhibits high robustness and reliability in operation.

[0004] This problem is solved with a check valve assembly according to the features of claim 1. Preferred embodiments are described in the dependent claims and the following description of exemplary embodiments with reference to the figures.

[0005] They show: Fig. 1a a first embodiment of an exemplary check valve assembly, Fig. 1b a second embodiment of the exemplary check valve assembly, Fig. 2a the first embodiment in exploded view, and Fig. 2b the second embodiment in exploded view.

[0006] The Fig. Figure 1a shows a first embodiment of an exemplary check valve assembly 1, which can be inserted into a receiving opening of a receiving body of a hydraulic power unit for a motor vehicle braking system. The check valve assembly 1 is hydraulically arranged between a hydraulic fluid reservoir and a hydraulic fluid delivery device of the hydraulic power unit.

[0007] As a pressure differential-controlled valve, check valve assembly 1 serves to allow the flow of hydraulic fluid from the hydraulic fluid reservoir into the hydraulic fluid delivery system. During the suction phase of the hydraulic fluid delivery system, check valve assembly 1 opens due to a vacuum, allowing the hydraulic fluid to flow from the higher-lying hydraulic fluid reservoir to the hydraulic fluid delivery system. When the vacuum is released, check valve assembly 1 returns to its closed position. This design also applies to the subsequent description of a second embodiment.

[0008] Check valve assembly 1 according to Fig. 1a comprises a valve sleeve 2, which is designed to be pressed or clinched into a receiving opening. Valve sleeve 2 comprises an inwardly directed flange 14. Flange 14 provides a central inlet opening 15 for the hydraulic fluid from the pressure medium reservoir. An inclined or conical valve seat 6 for a closing element 3 is formed on the inner edge of the flange 14. On the side opposite the flange 14, valve sleeve 2 forms an outlet opening 16 by means of its wall, through which the hydraulic fluid flows to the pressure medium delivery device when the check valve assembly 1 is open.

[0009] The closing element 3 is essentially mushroom-shaped and comprises a head 7 with a spherical contour, which is designed to seal against the valve seat 6, and a central shaft 8 extending away from the head 7. Due to the spherical shape of the head 7, it always seals against the conically shaped valve seat 6 in the closed position.

[0010] The closing position is assumed by the closing element 3 due to the preload provided by the compression spring 4. A spring retaining element 5 is provided for this purpose, which is connected to the valve sleeve 2 by means of an exemplary snap connection and against which the compression spring 4 is supported. Thus, the compression spring 4 rests within the spring retaining element 5 and presses downwards against the head 6 of the closing element 3, so that it rests against the valve seat 6. At the same time, the shaft 8 of the closing element 3 is located within the compression spring 4.

[0011] Spring retaining element 5 in the first embodiment according to the Fig. 1a is made of a metallic material and is preferably designed as a stamped and bent part.

[0012] The second embodiment of check valve assembly 1 according to the Fig. 1b is structurally largely identical to the first embodiment. In this embodiment, spring retaining element 5 is designed as an injection-molded plastic part.

[0013] Based on the first embodiment of check valve assembly 1 according to the Fig. 2a will show in more detail the exemplary connection of spring retaining element 5 with valve sleeve 2.

[0014] To fasten spring retaining element 5 to valve sleeve 2, an internal, circumferentially extending groove 11 is formed in the wall of valve sleeve 2. The groove 11 is designed so that snap hooks 10 formed on the spring retaining element 5 engage positively in it. For this purpose, the spring retaining element 5 comprises a central ring base 9 from which a number of elastically deformable arms 13 extend axially. For example, four arms 13 are provided, which are arranged symmetrically. The arms 13 are angled outwards and encompass the outwardly directed snap hooks 10 at their respective ends. Furthermore, the central ring base 9 forms an opening 10 for the shaft 8 of the closing element 8, which is guided radially.

[0015] In the second embodiment according to the Fig.2b preferably five arms 13 are provided, which were formed from plastic by injection molding. These arms 13 are also arranged symmetrically around the ring base 9.

[0016] The spring retaining element 5, with its elastically deformable arms 13, has the advantage that it can be easily clamped into the valve sleeve 2 during assembly. For this, the arms 13 only need to be pressed slightly radially inwards, and the snap hooks 10 can engage in the groove 11. This creates a check valve assembly 1, which comprises only four individual parts and can be easily manufactured. Reference symbol list 1 Check valve assembly 2 Valve sleeve 3 locking elements 4 compression springs 5 Spring retaining element 6 valve seat 7 heads 8 shaft 9 ring base 10 snap hooks 11 Nut 12 Opening 13 arms 14 flange 15 Entrance opening 16 Outlet opening QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 102 34 541 A1

[0002]

Claims

[1] Check valve assembly (1) for a hydraulic unit of a motor vehicle brake system, comprising a valve sleeve (2) by means of which the check valve assembly (1) can be inserted into a receiving opening of a receiving body of the hydraulic unit, wherein the valve sleeve (2) comprises a valve seat (6) against which a closing body (3) bears in a sealing manner due to a spring force applied by a compression spring (7), wherein the compression spring (7) is supported on the one hand on a spring retaining element (5) and on the other hand presses on the closing body (3), characterized by that the spring retaining element (5) is connected to the valve sleeve (2) by means of a snap connection. [2] Check valve assembly (1) according to claim 1, characterized by that the spring retaining element (5) comprises a number of snap hooks (10) which engage in a form-fitting manner in a groove (11) running circumferentially in the valve sleeve (2). [3] Check valve assembly (1) according to claim 2, characterized by that the spring retaining element (5) comprises a central ring base (9) from which elastically deformable arms (13) extend, each having a snap hook (10). [4] Check valve assembly (1) according to claim 3, characterized by that the central ring base (9) comprises an opening (12) within which a shaft (8) of the closing body (5) is guided axially displaceably. [5] Check valve assembly (1) according to claim 3 or 4, characterized by that the compression spring (4) rests with a lower turn on the central ring base (9) of the spring retaining element (5). [6] Check valve assembly (1) according to one of claims 1 to 5, characterized by that the spring retaining element (5) consists of a metallic material or of plastic.

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