Valve device for controlling pressure medium

The invention relates to a valve device for controlling pressure medium. Arranged in a valve housing is a valve piston which forms a first valve, together with a valve seat which is fixed to the housing. Via the first valve, a first pressure medium chamber, which is connected to a pressure medium source, can be connected to a second pressure medium chamber which is connected to a consumer. A second, a third and a fourth valve are provided in the valve piston. The valve body of the second valve is held on its seat by a restoring force and can be raised from said seat by means of an actuating device. Via the second valve, a control chamber, which is bounded by the valve piston and is located opposite the first and second pressure medium chambers which are likewise bounded by the valve piston, can be connected to an auxiliary chamber. When the second valve is open, the auxiliary chamber can be connected via the third valve optionally to the first or the second pressure medium chamber, depending on which of the two pressure medium chambers has the lower pressure. Via the fourth valve and a throttling port, the control chamber can be connected optionally to the chamber having the higher pressure. The valve piston has an effective surface which is subjected to the pressure of the second pressure medium chamber in the opening direction of the first valve.