Vacuum signal full-automatic control device

An inlet of a vacuum pump is communicated with an inner cavity of a shell of the centrifugal pump through a vacuumizing pipeline, a vacuum signal switch is connected to the pipeline in series, the vacuum signal switch comprises a shell sliding rod, a floating ball, a lower sealing plate and a position switch, an air outlet is formed in the upper portion of the shell, and an air inlet is formed inthe bottom of the shell. The sliding rod is vertically installed in the shell, the bottom of the sliding rod is connected with the sealing plate, the sealing plate is supported on the bottom face in the shell, the floating ball is connected to the sliding rod in series, the floating ball is connected with the sealing plate, the top of the sliding rod extends out of the top of the shell, and the lower contact of the position switch is installed at the extending end of the top of the sliding rod. And when the position switch is closed, a control signal is sent to the vacuum pump. The device is simple in structure, autom