| 摘要 |
<p>A control valve for the application of a desired pressure in a working circuit, having a pressure chamber connected with a pressure source, a control chamber separated during the rest position of the valve from the pressure chamber by a first seat valve which connects with a working circuit and a pressureless connection during the rest position of the valve, and finally the control valve has an activating piston 14, by means of which, when the control valve is operated, first the connection between the control chamber and the pressureless connection is interrupted and then the first seat valve is opened. Additionally, a further seat valve is interposed into the connection between the pressure source and the pressure chamber, and a control piston 7 is provided to open seat valve 6 when exposed on the one side to the pressure in the pressure chamber 9 and on the other side to the pressure applied in the working circuit. The surface of the control piston exposed to the pressure in the pressure chamber is, in contrast to its surface exposed to the pressure in the working circuit, dimensioned so much smaller and/or the spring 11, acting on the piston and supporting the pressure in the working circuit is dimensioned in such a way, that this further seat valve, on the one hand, is closed during a state of no-pressure in the working circuit, however, on the other hand, during the opening of the first seat valve and the increase of pressure in the working circuit connected therewith, the control piston is displaced in such a manner that the further seat valve is opened.</p> |
