A control method of a non-high frequency plasma cutting machine

Abstract

The invention relates to a non-high frequency arc ignition plasma cutting machine, and discloses a control method of the non-high frequency plasma cutting machine. Compress the gas source and control the three-way valve to conduct the cutting torch and the gas pipe, a pilot arc is formed between the electrode in the cutting torch and the guide terminal, and the control circuit controls the main arc circuit to receive the pilot arc to form a working arc; stop the cutting step, control the compressed gas source to close, Control the three-way valve to conduct the cutting torch and the outside atmosphere; repeat the start-up steps, control the three-way valve to conduct the cutting torch and the gas pipe, short-circuit the constant current between the electrode in the cutting torch and the guide terminal, and control the compressed gas source to start the gas supply to form a pilot arc. Then a working arc is formed; the three-way valve allows the residual high-pressure gas in the cutting torch to be released into the atmosphere in the opposite direction of the cutting torch, realizing rapid discharge, ensuring the stable contact between the electrode and the nozzle during re-cutting, and improving the lead-time. The arc success rate ensures the arc ignition quality.

Description

technical field [0001] The present invention relates to a non-high-frequency arc cutting machine, more specifically, it relates to a control method of a non-high-frequency plasma cutting machine. Background technique [0002] At present, most cutting machines produced in China use high-voltage and high-frequency arc ignition circuits. The principle is to use high-voltage and high-frequency to ionize the air between the electrode and the nozzle in the torch, and then generate a pilot arc for arc transfer cutting. The arc striking circuit of this kind of high-frequency arc-igniting plasma cutting machine is difficult to guarantee the success rate of arc striking, and the electromagnetic interference and high-frequency radiation generated by high-voltage and high-frequency discharge during arc striking are difficult to control, and the effect of applying it to CNC cutting is not ideal. [0003] Therefore, a cutting machine with a non-high-frequency arc ignition circuit has appe...

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Problems solved by technology

[0004] However, non-high-frequency arc ignition requires air pipes to provide compressed air to blow off the electrodes and nozzles in the torch. The cutting machine needs to be opened and closed frequently during work, and the air pipes need to be opened and closed frequently. After the air pipes are closed, the compression in the air pipes The air will continue to be ejected, and then when the cutting machine is started quickly, the residual gas pressure is enough to support the separation of the electrode and the nozzle in the cutting torch. The arc striking speed of fast opening and closing is slow, and the success rate of arc striking is also low

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