| 摘要 |
PURPOSE:To enable high speed response and to prevent the stray of output air pressure caused by the breaking of a power source, by discharging held output air pressure from a second nozzle flapper system when the power source is interrupted. CONSTITUTION:The output air pressure from a pilot valve 16 is applied to the bellows 24 of a feedback system through a solenoid valve 28 and air pressure to a second nozzle flapper system 27 follows the output air pressure. If a power source is broken, a signal PS is turned OFF (the breaking of the power source) and a solenoid valve 22 is changed over to the side of a nozzle 26 while the pilot valve 16 is communicated with the nozzle 26 and the solenoid valve 28 is closed. Therefore, the feedback system of the second nozzle flapper valve 27 is held to the value directly before the breaking of the power source and back pressure balanced with the held pressure is discharged as the output air pressure from the nozzle 26 through the solenoid valve 22 and the pilot valve 16. |
