Bucher Hydraulics Ag

Markus Eschweiler

Hans Staiger

Horst Kahl

J&ouml;rg Ludwig

A pilot valve () is designed as a directional control valve in which a control slide () is movably disposed in a longitudinal bore () of the valve body () so as to control the flow of hydraulic oil between two working connecting bores (A, B), a pump connecting bore (P), and a reservoir connecting bore (T). A check valve () which is biased with the aid of a bias spring () is disposed within the control slide (). The check valve () is connected to an auxiliary control groove () via a first transversal bore () while being connected to the B-reservoir groove () via a second transversal bore (). The check valve () is to be opened from working connecting bore B while the auxiliary control groove () is arranged between the B control groove () and the B reservoir groove () and is delimited on both sides by means of sealing cylindrical areas ().

Control valve for a hydraulic motor

The present invention relates to a high-pressure hydraulic valve in which the housing ( ) at least and also preferably the operational parts, such as the main control piston ( ), the manometer piston ( ) and the like which are arranged inside said housing ( ) and influence the hydraulic oil flow, are made of an aluminium alloy that can be hardened and tempered. The weight of the high-pressure hydraulic valve can therefore be substantially reduced. The surfaces of the parts made of the aluminium alloy that can be hardened and tempered are advantageously submitted to anodic oxidation in order to increase even more their wear resistance. This type of high-pressure hydraulic valve with a particularly light weight is mainly intended for use in mobile hydraulic systems such as those used in mobile cranes, in lifting platforms and in excavators.

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Remscheid, Germany

Markus Eschweiler