Hydraulic multiway valve

Abstract

The hydraulic multiway valve comprises a control piston (main piston,), which is displaceable against the force of a spring (main spring,) by the plunger of a magnet (,) from its first position (closing position) to its second position (opening position). In the closing position, a pressure chamber (,) with a pump connection (P) is closed toward a consumer chamber (,), and the consumer chamber with a consumer (A) is opened toward a return flow chamber (,) and a reservoir connection (R). In the opening position, the consumer chamber (,) is closed toward the return flow chamber (,). To this end, the consumer chamber (,) and the return flow chamber (,) are arranged at the opposite ends of the main piston (,), namely the consumer chamber (,) on the side facing the magnet, and the return flow chamber (,) on the side facing away therefrom. A central channel (,) extends through the main piston. The central channel interconnects the consumer chamber (,) and the return flow chamber (,). A magnet plunger acts upon a plunger piston, which is displaceable in the valve housing in coaxial relationship with the main piston, and which comprises a seat end facing the main piston (,), through which it closes the central channel, when it contacts the main piston. A power control unit recognizes errors in the operation of the magnet and the valve, and further insures that adequate holding forces act upon the main piston and power use to operate the valve is minimized.