Servo valve with two regulating stages for hydraulic actuator for doors, roofs, etc. of motor vehicles has additional stage with second flow aperture closed by valve element for rapid opening of large flow section

摘要

The valve (16) has a housing (20) and a bore (24) with a valve element (25) to open/close a hydraulic medium passage. The element is loaded in closing direction by an elastic element (33), and by an additional force via a control connection (36). It blocks a flow aperture (26) in the passage, which is smaller than the bore. The valve has at least one further regulating stage, with a second flow aperture (30) of the same size as the bore, and blocked by a second valve element (29). This is guided in an extension (28) of the bore, which is wider than the second aperture. The last stage is formed by an outlet (32) opening into the extension, and the last valve element, which opens/closes this outlet. The valve is part of a hydraulic actuator for sliding roofs, doors, etc. of motor vehicles.