| 摘要 |
PURPOSE:To minimize the abnormal rise of revolution speed of a hydraulic machinery by fixing a guide vane to a small opening degree less than a prescribed opening degree when an electrically driven servomotor is put into powerless state. CONSTITUTION:When an electrically-driven servomotor is put into powerless state, a detection signal deenergizes a single type solenoid valve 9, and the compressed air passes through the port on the lower side of the single type solenoid valve 9 and acts onto the right side of a cylinder 10. In this case, the operation speed of a piston 11 can be adjusted by installing an adjustable throttle 13 on the air feeding side. Therefore, a brake 6 for fixing the electrically driven servomotor can be operated, and a guide vane in the drift state can be fixed at the sufficiently small opening degree less than a prescribed opening degree. Therefore, the abnormal rise of the revolution speed of a hydraulic machinery can be prevented. |
