| 摘要 |
PURPOSE:To prevent the occurrence of noise, and prevent the gaseous quantity of suction/discharge from being decreased by preventing a gap between a movable iron core and a stationary iron core from being smaller with time by means of the action of a second spring interposed between a coil and the bottom section of the movable iron core. CONSTITUTION:When a driving power supply 7 is turned on, specified voltage is applied to a coil 201, so that a movable iron core 3 is moved to to the right. This configuration thereby allows a bellows 101 to be extended, so that measured gas and the like are introduced into an inner chamber 104 through an intake port 1 with a valve 103a opened. When the driving power supply 7 is turned off thereafter, applied voltage to the coil 201 becomes zero, the movable iron core 3 is moved to the left, the bellows 101 is contracted, the valve 103a is closed, and a valve 103b is opened, so that measured gas and the like within the inner chamber 104 are discharged out of a discharge port 2. In this case, when the bellows intend to be extended with time by means of a first spring 5', a second spring 8 is subjected to force in the direction of compression. This configuration thereby allows force pushing back the bellows 101 to be increased, so that a gap (d) is prevented from being small. The bellows can thereby be prevented from being deformed with time. |
