How to control the air pressure of NC plasma cutting machine

When the NC plasma cutting machine is working, if the working air pressure is much lower than the air pressure required by the specification, it means that the jet speed of plasma arc is weakened and the input air flow is less than the specified value. At this time, a high-energy and high-speed plasma arc can not be formed, and then the appearance of poor cutting quality, impenetrability and tumor accumulation is formed. The reasons for insufficient air pressure are: insufficient air intake of air compressor, low pressure adjustment of air conditioning valve of cutting machine, oil pollution in solenoid valve and poor air passage. The solution is to investigate the output pressure of the air compressor before use, and adjust it if it does not meet the requirements.

When using CNC plasma cutting machine, it is often necessary to provide auxiliary working gas in order to achieve better cutting effect. The working gas can be selected according to the nature of the cutting material, such as air, oxygen and carbon dioxide. Different auxiliary gases have different functions in practical use, such as oxygen can increase the cutting temperature and carbon dioxide can slow down the oxidation speed of the cutting surface. However, no matter what kind of auxiliary working gas is used, the control of gas flow by CNC plasma cutting machine will obviously affect the final cutting quality products. The following Wuhan Huayucheng CNC will introduce you to this knowledge:

The effect of NC plasma cutting is closely related to cutting working gas. Working gas is cutting gas and auxiliary gas. In general, the appropriate working gas should be selected according to the type, thickness and cutting method of the cutting material. Cutting gas should not only ensure the formation of plasma jet, but also ensure the removal of molten metal and oxide in the incision. Excessive airflow will take away more arc heat, shorten the jet length, lead to the decline of cutting ability and unstable arc; Too small gas flow will make the plasma arc lose its flatness, make the cutting depth shallow, and easily produce slag hanging; Therefore, the airflow must match the cutting current and cutting speed. Therefore, the adjustment of working gas during cutting is particularly important.

At present, most plasma arc cutting machines rely on air pressure to control the flow, because under the condition that the aperture of the gun body is fixed, controlling air pressure also controls the flow. The gas pressure for cutting materials with a certain thickness is usually selected according to the data provided by the equipment manufacturer. If there are other special applications, the gas pressure needs to be determined by the actual cutting test. Therefore, to achieve good cutting quality, not only technicians need to operate normally according to the process, but also technicians need to have sufficient cutting adjustment experience!

If the input air pressure far exceeds 0.45MPa, after the plasma arc is formed, too much air will blow away the converging arc column, which will lead to the energy dissipation of the arc column and weaken the cutting strength of the plasma arc. The reasons for high air pressure are: improper adjustment of input air, excessive adjustment of air filtration pressure reducing valve or failure of air filtration pressure reducing valve.

The solution is to check whether the air compressor is adjusted correctly and whether the pressure of the air compressor and the air filter pressure reducing valve is unbalanced. After startup, if you rotate the conditioning switch of the air filter pressure reducing valve, the display does not change, indicating that the air filter pressure reducing valve is out of order and needs to be replaced. Pressure or maintenance of air compressor. If the input air pressure has reached the requirements, check whether the adjustment of the air filtration pressure reducing valve is correct and whether the gauge pressure can meet the cutting requirements. Otherwise, ordinary protection and maintenance should be carried out for the air filtration pressure reducing valve to ensure that the input air is boring and dirty. If the input air quality is poor, it will cause oil pollution in the solenoid valve, and the valve core will be difficult to open and the valve port will not be fully opened. Something else The air pressure of the moment-cutting nozzle is too low, and the solenoid valve needs to be replaced; Small cross-section of airway can also cause low air pressure, so the trachea can be replaced according to the instructions.