| 摘要 |
In solenoid valves for the control of high-pressure fluid, experience has shown that an adhesion force arises between the spool (2) and the housing bore (3) after a certain time at rest and this force is greater than that which would correspond to the normal frictional resistance to be overcome at the beginning of a spool stroke. In order to be able to overcome this adhesion force more easily, the spool (2) is, in one end position, partially relieved of the axial pressure arising in service. This can be accomplished by means of a spring (10) which holds the spool (2) virtually in a floating condition. Spool-controlled branch conduits (14, 15) can also be provided, these being used to bring about hydraulic pressurisation of differential annular spool faces (16, 17). <IMAGE>
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