Control method of non-high-frequency plasma cutting machine

Abstract

The invention relates to a non-high-frequency arc starting plasma cutting machine and discloses a control method of a non-high-frequency plasma cutting machine. A cutting starting step, a cutting stopping step, a repeated starting step and a three-way valve are included, wherein a control circuit starts a cutting power source circuit, an electrode in a cutting torque and a guiding terminal are ina constant current short circuit, a compressed gas source is opened, the three-way valve is controlled to connect the cutting torque with a gas pipe, a guiding arc is formed between the electrode in the cutting torque and the guiding terminal, and the control circuit controls a main arc circuit to receive the guiding arc and form a work arc; the compressed gas source is controlled to be closed, and the three-way valve is controlled to connect the cutting torque with outside atmosphere; the three-way valve is controlled to connect the cutting torque with the gas pipe, the electrode in the cutting torque and the guiding terminal are in the constant circuit short circuit, the compressed gas source is controlled to start gas supplying, the guiding arc is formed, and then the work arc is formed; high-pressure gas remaining the cutting torque can be released into the atmosphere opposite to the cutting torque, fast releasing is achieved, stable contact between the electrode and a spray nozzleduring re-cutting is guaranteed, the arc starting success rate is increased, and the arc starting quality is guaranteed.

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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