| 摘要 |
<p>PURPOSE: To facilitate reversion of the feed direction of fluid by a pump by a method wherein a synchronous mode between first and second working means is selectively switched and caused to effect synchronous mode by a control means. CONSTITUTION: A bellows 30 being a variable volume device is connected to a port 18, and the content volume of the bellows 30 is changed through the working of electromagnetic coils 28 and 34 by a control device 40. When a valve element 24 is situated in a first switching position wherein ports 18 and 22 are intercommunicated, the bellows 30 is switched from a first state where a content volume is relatively small to a second state wherein a content volume is comparatively large. Further, the bellows is brought into a first synchronous mode wherein switching from a second state to a first state is effected. Further, when the valve element is in a second switching position wherein the ports 18 and 20 are intercommunicated, the bellows 30 is switched from a first state to a second state. Further, the belows is selectively switched to a second synchronous mode wherein switching from the second state to the first state is effected and brought into synchrnous operation and the fluid direction of a pump is reversed.</p> |
