| 摘要 |
<p>PURPOSE: To enable the operation of a control valve independently of the setting of a servomotor by disposing the control element of the servomotor between the inner ends of a spool being coaxially symmetrical, and by applying a pressure medium on auxiliary pistons via a selector valve so as to resist the spring force pressing it with a spool. CONSTITUTION: Spools 2, 2a having control pistons, 4, 5, 4a, 5a and auxiliary pistons 8, 8a being coaxially disposed in a mirror symmetrical manner relative to one another are provided inside a housing 1, and adjustable constituent members 21, 21a are provided to the free ends of the control pistons 4, 4a. An eccentric ring 19 having an outer ring 20 being driven by a target value motor 17 is provided between the constituent members 21, 21a, and it is made to be a mechanical support part of the spools 2, 2a receiving the load of springs 11, 11a. Auxiliary pistons 5, 5a are driven by a pressure medium via a selector valve 24 against the pressing force of the springs 11, 11a so that they are moved away from the outer ring 20. Thus, the control valve can be operated independently of the setting of a servomotor.</p> |
