| 摘要 |
PROBLEM TO BE SOLVED: To provide a two stage actuator with an easy structure. SOLUTION: A first actuator 11 has a negative pressure chamber 31 and an atmosphere chamber 32 divided by a diaphragm 22. The diaphragm 22 is joined to an activating rod 24. A second actuator 12 can form a pressure sensing chamber 52 communicating to an negative pressure chamber 51 and an negative pressure chamber 31 because a built-in middle stopper 42 is set onto a bottom wall. When negative pressure is developed into only the negative pressure 31, the activating rod 24 is lifted. Furthermore, the activating rod 24 is regulated to move in a given range by the stopper shaft 42b of the middle stopper 42 that is pressed to the bottom wall because of the difference pressure between the negative pressure chamber 51 and the pressure sensing chamber 52, and thereby, the activating rod 24 makes a first stage stroke. When negative pressure is developed into the negative chamber 31 and an inner space 50, the activating rod 24 is further lifted with the middle stopper 42 together via the stopper shaft 42b, and thereby makes a second stroke. |
