| 摘要 |
The valve comprises a valve body (10) having an elongated bore (11) and a plurality of ports (15-19) in the side wall of the bore. A control port (23, 25) is located at each end of the bore surrounded by a valve seat (26, 27). A shuttle valve member (45) slides axially in the bore between the two valve seats to control the flow of fluid between the side wall ports. Bleed passageways (41, 42) provide high pressure fluid to chambers (28, 29) in the bore adjacent to the control port valve seats. A solenoid valve (14), alternatively connects one control port to a low pressure region and blocks the other to cause the valve member to move between positions in which it engages one or the other control port valve seat. The ratio of the cross- sectional area of the valve member to the cross-sectional area of the valve seats is in the range between 2 to 1 and 4 to 1, and is preferably no more than 3 to 1. <IMAGE> |
