Piston pump for a brake system

Abstract

The invention relates to a piston pump, in particular for a hydraulic vehicle brake system with slip control. The piston pump (10) has a piston (16), which is received in a bush (26) that is inserted into a cylinder bore (12) of a pump housing (14) that is closed in pressure-tight fashion by a closure part (68). For simpler assembly, the invention proposes that the closure part (68) be connected to the bush (26) by means of a snap or detent connection (72, 80). As a result, a preassembled unit that can be manipulated easily before insertion into the pump housing (14) is obtained in a simple way.

Description

PRIOR ART[0001] The invention relates to a piston pump as generically defined by the preamble to the main claim.[0002] The piston pump of the invention is intended in particular as a pump in a brake system of a vehicle and is used to control the pressure in wheel brake cylinders. Depending on the type of brake system, the abbreviations ABS, ASR, FDR and EHB are used for such brake systems. In the brake system, the pump serves for instance to return brake fluid from a wheel brake cylinder or a plurality of wheel brake cylinders to a master cylinder (ABS) and / or to pump brake fluid out of a supply container into a wheel brake cylinder or a plurality of wheel brake cylinders (ASR or FDR or EHB). In a brake system with wheel slip control (ABS or ASR) and / or a brake system serving as a steering aid (FDR) and / or an electrohydraulic brake system (EHB), the pump is needed. With the wheel slip control (ABS or ASR), locking of the wheels of the vehicle during a braking event involving strong ...

AI Technical Summary

Benefits of technology

[0004] In the piston pump of the invention as defined by claim 1, the closure part and the bush are joined together by means of a snap or detent connection. This has the advantage that the bush and the closure part are joined together by simply being put together before insertion into the pump housing. An additional connection operation, for instance crimping as known from the prior art, is dispensed with. The bush and the closure part form an easily manipulated preassembled unit, which can be inserted into the pump housing simply, for instance by press-fitting. Since the connection between the closure part and the bush has only a secondary function, it must hold the closure part on the bush until the piston pump has been inserted into the pump housing; then an approximately aligned orientation of the closure part and the bush suffices, and sealing between the closure part and the bush is unnecessary, so that a snap or detent connection suffices. After insertion into the pump housing, the closure part and the bush are held in a position aligned with one another by the pump housing; sealing exists between the pump housing and the bush, or the closure part. The connection between the closure part and the bush has no further importance once these two parts have been inserted into the pump housing. A snap connection, which can be undone again by pulling the closure part and the bush apart, suffices to connect the closure part to the bush. A detent connection that cannot be done is equally suitable for connecting the closure part to the bush.[0005] Advantageous features and refinements of the invention defined by the main claim are the subject of the dependent claims.

Problems solved by technology

A disadvantage is that the closure part must be joined to the bush in an additional work step.

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