| 摘要 |
Flow of high pressure hydraulic fluid between passages 7, 8 and 9 of a manifold 5 is controlled by movement of poppet 32 between valve seats 34 and 35 under the action of biassing spring 25 and solenoid 4. The solenoid region is connected to pressure passage 9 by way of duct 52 to give balanced operation and minimize thickness of casing 15. The poppet 32 is surrounded by cylindrical member 33 with an annular groove communicating with passage 11. Transverse to the direct flow path between the poppet 32 and the passage 11 parallel slots are cut across the end faces and flanges 39 of the cylindrical member 33 to control the fluid flow. In an alternative construction the slots are formed in a central annular region between two ring seats against which a ball-shaped poppet engages. The valve assembly 1 can be reversed with respect to the manifold 5 to connect ports 10, 11 and 12 to passages 9, 8 and 7 respectively to convert from normally closed to normally open operation. <IMAGE> |
