Control valve device

Abstract

Control valve device, in particular for hydraulic systems having high flow ates, comprising a housing provided with a bore within which a piston slide means can be displaced from a neutral position with zero-pressure flow to at least one control position, and further comprising at least one pressure passage leading to and at least one discharge passage leading away from the housing bore, said pressure passage and discharge passage being adapted to be interconnected through flow conduits provided in the piston slide means. In known control valve devices of this type, the flow paths for the zero-pressure flow must be very large in the case of high flow rates; when the piston slide means carries out adjusting movements, undesirable jamming forces are caused at said piston slide means which obstruct the adjusting movements, herein avoided by providing the features that within the housing bore the discharge passage orifice is displaced relative to the pressure passage orifice in the longitudinal direction of the bore, that these orifices are diametrically opposed by recesses of the same size, which are each open towards the housing bore and which each have applied thereto the pressure existing in the opposite passage via connection passages provided within the housing or within the piston slide means, and that the piston slide means has provided therein in front of each passage orifice a longitudinally extending pocket bridging the displacement between the passage orifice and a neighboring recess.