| 摘要 |
<p>The present invention relates to a pressure control valve which returns a high pressure flow to a hydraulic tank to protect a hydraulic system when the pressure of a working fluid in a hydraulic pump exceeds a set pressure level. The pressure control valve of the present invention includes: a sleeve at which an inlet for the inflow of working fluid and a low-pressure passage in communication with the hydraulic tank are disposed; a main poppet which opens or closes the low-pressure passage against the inlet; a main poppet spring which elastically biases the low-pressure passage closed against the inlet into an initial state by pressurizing the main poppet; a pilot poppet at which an orifice passage is disposed such that, when a pressure higher than the set pressure is generated in a pressure chamber and an inner passage of a valve seat is opened, the pressure is controlled and a sliding state is maintained at a valve seat; and a pilot poppet spring which elastically biases the closed inner passage of the valve seat into an initial state by pressurizing the pilot poppet.</p> |
