| 摘要 |
PURPOSE:To enable to obtain the preset gas pressure without exceeding the preset gas pressure even when a solenoid valve is opened and the gas pressure is suddenly applied by a method wherein a valve body is structured as follows; that is, the valve body is once opened to the full opening position by a control device, a solenoid valve is opened after the valve is opened to the full opening position, simultaneously, the valve body is moved to the position for supplying the preset gas quantity. CONSTITUTION:A valve body 4 is once opened to the full opening condition before a solenoid valve 2 is opened by a control device 11, then moved nearby the full opening state. Thereafter, the solenoid valve 2 is opened, the valve body 4 is controlled to be moved to the designated position at the same time when the solenoid valve 2 is opened. A gas pressure is not applied to the valve body 4 when the solenoid valve 2 is closed. At the opening of the solenoid valve 2, instantly, the gas pressure is applied to the valve body 4. As the pressure loss at the front and rear side of the valve body 4 can be considered as zero value, the balance of the valve body 4 can be simultaneously obtained at the time the gas flows to the downstream side of the valve body 4. The valve body 4 is already moved to nearly full opening position when the solenoid valve 2 is opened, meantime, the valve body 4 is forced to be moved to the designated position at the same time when the solenoid valve 2 is opened. Therefore, even when the valve body is pressed by the gas pressure, the valve does not move passing over the designated position, accordingly, the gas overflowing can be prevented. |
