| 摘要 |
PURPOSE:To enable the accurate operation of a piezoelectric actuator without decreasing the clamping force to a plunger by a method wherein, when the operating speed of the piezoelectric actuator is decreased, only the applied voltage to a piezoelectric element for stroke use is changed, and the applied voltage to a piezoelectric element for clamp use is kept constant. CONSTITUTION:In accordance with an input from a valve opening and shutting switch, a control signal is output to an actuator A of a diaphragm valve V1 from a control unit C, and drives each piezoelectric element to make said valve V1 execute an open and shut operation. At the time of operation speed control of the piezoelectric actuator, only the applied voltage to a piezoelectric element for stroke use is changed, and the applied voltage to a piezoelectric element for clamp use is kept constant. As a result, also when the operation speed is decreased, only the applied voltage to the element for stroke use is changed, and the applied voltage to the element for clamp use can be kept constant. Thereby, the clamping force to a plunger is not decreased, and the generation of plunger slip can be prevented, so that the accurate operation of piezoelectric actuator is enabled. |
