HYDRAULIC/PNEUMATIC CONTROL VALVE WITH FAIL-SAFE FUNCTION

• Main Authors: GEIS, HARALD, ROTT, HORST
• Format: Patent
• Language: English; French; German
• Published: 06.08.2008
• Subjects: BLASTING; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR; FLUID-PRESSURE ACTUATORS; FLUID-PRESSURE ACTUATORS, e.g. SERVO-MOTORS; HEATING; HYDRAULICS OR PNEUMATICS IN GENERAL; LIGHTING; MECHANICAL ENGINEERING; SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; WEAPONS

The invention relates to a hydraulic/pneumatic control valve, comprising a control slide (3) which is actuated by means of an actuating element (1) of an actuating device (2), which control valve is in force equilibrium with the pressure acting on the end faces of the slide (3), which control valve, in a first position, produces a connection via a relief duct (6) in the control slide (3) from a pressurized port point P to at least one port point A for a load, and which control valve, in a second position, breaks the connection of the port point A to the port point P and relieves the load A of pressure at a port point T into a tank via the relief duct (6), wherein the relief duct (6) is connected to the port point A and to the port point T, and is guided up to a port point (10), which is embodied as a control opening (8) in a retaining space (7) of the control valve, of the control slide (3) with the actuating element (1), and the connection of the relief duct (6) to the port point T can be controlled by the actuating device (2), a force-fitting and form-fitting connection in the form of a coaxial seal is provided between the control slide (3) and the actuating element of the control slide, and comprising a safety function, which, in the event of a malfunction of the control valve, relieves the load port point A of pressure to the port point T in the non-actuated state irrespective of the position of the control slide (3), wherein the port point A is relieved of pressure via the open seal (9) and the retaining space (7) to the tank (port point T). The invention is characterized in that the coaxial seal (9) is arranged at that side of the actuating element (1) which faces towards the port point (10).