| 摘要 |
A normally-open, solenoid-controlled valve rapidly controls the flow of liquid between a high pressure supply and a relatively lower pressure drain. The valve includes a stationary valve-seat spindle and a cylindrical valve sleeve encircling and slidable along part of the valve-seat spindle. The valve-seat spindle is provided with an annular control edge and the valve sleeve includes a frustoconical pressure-responsive contact surface which is moved into and out of valve-closing contact with the control edge by means of axial reciprocation of the valve sleeve between valve-closed and valve-open positions. The valve-seat spindle includes a flow passage therein which is in continuous fluid communication with a high pressure fluid inlet in a valve housing and which extends to and discharges into a plenum region formed between the spindle and the sleeve adjacent to the control edge and relatively toward that part of the seat spindle along which the valve sleeve slides. When energization of the solenoid is discontinued, the high pressure liquid in the plenum acts axially on the valve sleeve, and particularly the pressure-responsive contact surface, to rapidly open the valve. The response rate and simplicity of the valve are enhanced by the absence of a biasing spring. The valve is suited for use as a bypass valve in integral combination with a high pressure fuel injector nozzle of the pressure-responsive type. |
