| 摘要 |
PURPOSE:To set the rated output of a motor small by controlling a pressure control valve between the intake port of a vacuum pump and a vacuum container with the input current of the motor of the vacuum pump. CONSTITUTION:A vacuum exhaust device constituted of a vacuum pump 2, a vacuum pipeline 3, a pressure control valve 4, and a controller 6 is connected to a vacuum container 1. The controller 6 has the input current value of a motor 5 as an input signal and the control signal of the pressure control valve 4 as an output signal. The pressure control valve 4 is controlled by the controller 6 so that the input current value of the motor 5 does not exceed a preset value. Accordingly, the intake port pressure of the vacuum pump is reduced, and the vacuum pump can be operated within the range not exceeding the rated output of the motor.
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