| 摘要 |
PURPOSE:To surely open and close a valve with small driving force by energizing a motor shaft and a valve shaft in the opening and closing direction of the valve, respectively, with a spring, and setting the press force of the spring to energize the valve in open direction relatively small. CONSTITUTION:A reciprocating valve 5 is opened and closed by the reciprocating motor shaft 33 of an electric motor 20 rotating normally and reversely. In this case, a valve shaft 7 is energized in the open direction of the valve by this spring 12. On the other hand, a motor shaft 33, which drives the valve shaft 7 coaxially, is energized in the open direction of the valve 5 by this spring 44. And, the press force of the spring 44 to the motor shaft 33 is set smaller than the press force of the spring 12 to the valve shaft 7. Hereby, the drive force of the electric motor 20 required for opening the valve 5 is made smaller than the close-up force of the valve 5, whereby the downsizing of the valve 5 and the electric motor 20 can be accomplished. |
