| 摘要 |
<p>A four way valve assembly is provided which includes a main valve member operable by independent pilot valve actuation. The independent pilot operation means that the main valve stroke can be varied over a relatively wide range, enabling the valve to be produced in a number of sizes without requiring redesign of the pilot valve portion of the valve. A pilot body is mounted to the main valve and has a movable plunger of a conventional solenoid actuator attached to it. The plunger extends within the pilot body and has a loose fitting pilot slide mounted to its free end. The relative loose fitting pilot slide reduces the need for close manufacturing tolerances for the component parts used in constructing the pilot valve portion of the valve. The pilot slide is maintained in sealed relationship with a wall of the pilot body by relatively high pressure fluid passing through the pilot valve body. Solenoid operation enables the pilot slide to direct the high pressure to respective ends of the main valve, moving the valve between at least first and second positions.</p> |
