Pressure control valve arrangement having an eccentrically mounted double magnet

Abstract

A pressure control valve arrangement is described for controlling the fluid pressure in an ABS brake system of a vehicle so that, during a tendency of individual wheels of the vehicle to lock, the brake pressure in at least one assigned brake cylinder can be matched adaptively, a) two diaphragm valves and two electromagnetic control valves, activatable by an electronic control device, for the pilot control of the diaphragm valves being provided in the housing of the pressure control valve arrangement, b) the two electro-magnetic control valves having a double magnet with two magnet coils and also magnet armatures cooperating with solenoid valve seats and actuable by current being applied to the magnet coils, c) the housing having at least one pressure medium connection, connected to a service brake valve, for acting with pressure upon and / or relieving the pressure of the pressure control valve arrangement and also at least one working connection for connecting to the brake cylinder, characterized in that d) a plane of symmetry of the mid-axes of the magnet coils of the double magnet of the electromagnetic control valves is arranged parallel, and offset by the amount of an eccentricity, with respect to a mid-axis of the pressure medium connection.

Description

FIELD OF THE INVENTION[0001]The present invention relates to a pressure control valve arrangement for controlling the fluid pressure in an ABS brake system of a vehicle.BACKGROUND INFORMATION[0002]ABS (antilock system) prevents the wheels from locking and comes into operation when greater adhesion than is transferable is demanded between a tire and the road, that is to say when the driver overbrakes. In overbraking, the central electronic control apparatus of the ABS brake system detects from rotational speed sensor signals the tendency of one or more wheels to lock and from this calculates the activation of the pressure control valve arrangement acting upon the assigned brake cylinder. The brake pressure is then set to optimal slip by the pressure control valve arrangement by lowering, holding or building up the brake pressure according to the wheel behavior and therefore the frictional conditions between the tire and road.[0003]ABS pressure control valve arrangements without a rel...

AI Technical Summary

Benefits of technology

[0008]The subject on which the exemplary embodiments and / or exemplary methods of the present invention are based is to develop a pressure control valve arrangement of the type initially mentioned in such a way that it can be manufactured and assembled more simply and more cost-effectively.

[0010]As explained initially, the mid-axes of the magnet coils are coaxial with the valve seats of the electromagnetic control valves, and in each case one valve seat is formed at one end of a pressure medium duct which connects the respective valve seat to the pressure medium connection. Since two electromagnetic control valves are present, two pressure medium ducts formed in the housing must consequently lead from the respective valve seats coaxial with the mid-axes of the magnet coils into the pressure medium connection. In this case, pressure medium ducts running obliquely, that is to say deviatingly from a vertical or from a horizontal, are to be avoided, so as to avoid having to rechuck the housing during manufacture.

[0012]The distance between the mouth of the connecting duct, arranged in the housing, in the pressure medium connection between the valve seat of one of the electromagnetic control valves and the pressure medium connection, on the one hand, and the mid-axis of the pressure medium connection, on the other hand, is then reduced, as compared with the prior art, because the mid-axis of one of the magnet coils of the double magnet and therefore also the valve seat, coaxial thereto, of the respective electromagnetic control valve and, too, the respective pressure medium duct can then be moved nearer to the mid-axis of the pressure medium connection and consequently issue into the pressure medium connection at a shorter distance from this mid-axis. The other pressure medium duct emanating from the valve seat of the other electromagnetic control valve then no longer needs to run parallel to the first, for example vertical pressure medium duct, but instead can issue, for example running in a horizontal direction, into an annular duct which is formed in a housing and which is connected in turn to the pressure medium connection. The pressure medium ducts then run in a vertical and a horizontal direction, so that the housing does not have to be rechucked during manufacture. The diameter of the pressure medium connection can thus be smaller and therefore more favorable in flow terms. In particular, a reducing sleeve can be dispensed with.

[0016]If a cover closing a pilot control space of one diaphragm valve, for example arranged laterally on a housing, with respect to the outside and fastened to the housing is then composed of at least one plastic, the wall thickness of this cover can be greater than in the prior art, in which both diaphragm valves are arranged laterally on the housing and, because of the standardized overall width of the housing, the thickness of the covers has to be smaller. The plastic cover which is thicker, as compared with the prior art, is then more rigid. The tendency of the cover to deformation therefore decreases, and so the safety of the respective diaphragm valve against leakage of the pilot control space is increased.

[0018]In this case, at least one of the covers may at the same time, with the effect of an advantageous double function, close a pressure medium duct formed in the housing and separated from the respective pilot control space.

Problems solved by technology

However, because a correspondingly large diameter of the pressure medium connection is unfavorable in flow terms, in practice a reducing sleeve which reduces the effective flow diameter is inserted into the pressure medium connection.

However, this procedure entails additional costs for producing and mounting the reducing sleeve, and, in view of the large number of pressure control valve arrangements delivered by a supplier of vehicles, this amounts in total to a relatively high sum.

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