| 摘要 |
<p>A hydraulic boost device is disclosed which includes a housing having an inlet, an outlet, and a bore communicating the inlet with the outlet. A piston is slidable in a boost chamber which is provided in the housing in fluid communication with the bore. A stepped valve member having larger, smaller and intermediate radial portions is slidable in the bore from a first position in which substantially uninhibited flow of fluid is permitted between the inlet and the outlet to a second position in which the intermediate portion of the valve defines a metering orifice with the wall of the bore. In this position, a portion of the fluid is directed into the boost chamber to slide the piston and the rest of the fluid flows through the orifice to the outlet.</p> |
