It can cut various complex shapes of the workpiece, and has the advantages of fast cutting speed, high efficiency, good cutting surface quality, precise cutting size, small thermal deformation of the workpiece and so on.The cut parts can be welded and applied directly without machining.But CNC plasma cutting machine is to use plasma arc to cut, it compared with oxygen cutting.There are still some defects, mainly reflected in the slant of the cutting surface is large, the finish is not as good as oxygen cutting.The main criterion for evaluating the quality of CNC plasma cutting is: the inclination of the cutting surface, the depth of the cutting seam, the amount of hanging slag, etc.A high quality cutting surface of its inclination should be less than 30, cut grain depth should be less than O. 15mm, and hanging slag less, easy to remove.Under the condition of voltage and current stability, the factors affecting the cutting quality are not only the quality of the electrode and the nozzle itself, but also two main reasons: one is the height and stability of the cutting nozzle;The second is the matching of cutting speed and working air pressure.
When the height of the cutting nozzle from the steel plate is controlled by the arc pressure adjustable device, the dynamic positioning accuracy can reach ± 0.013 shan, so the height of the cutting nozzle and the steel plate can be guaranteed to remain the same, so the inclination of the cutting surface is small and uniform, and the finish is good.When the height of the cutting nozzle from the steel plate is adjusted by hand.The cut steel plate should be laid flat as far as possible to reduce the number of adjusting the cutting torch.Ensure the stability of the cutting torch during the cutting process.In this paper, the height of cutting nozzle from steel plate is controlled at 6 ~ 8 by manual adjustment
Mm, through a series of cutting tests, the relationship between cutting speed (filth), working air pressure (P) and cutting quality is described.
The optimum cutting parameters of different thickness steel plate with different power were obtained.It provides reference for improving the cutting quality of CNC plasma cutting machine.
Numerical control plasma cutting machine is an advanced mechatronics equipment for cutting sheet metal, which has been widely used in shipbuilding, machinery manufacturing and other industries.There are many factors that affect the cutting quality of CNC plasma cutting machine, such as the design parameters of the cutting machine, operation control and cutting process.In order to improve the cutting quality, we have carried out a comprehensive cutting test on it. According to the analysis and sorting of the test data, we have obtained some of the best working parameters of the CNC plasma cutting machine.It is described as follows:
2. Test methods
The test equipment is four kinds of air plasma cutting machine of different power, each type of electrode, nozzle each 6 sets.The cutting torches of the four air plasma cutting machines are installed on the cutting car of the numerical control cutting machine in sequence.Each type of air plasma cutting machine has to complete the whole process of testing separately, that is, cutting different thickness 'A3 steel plate at different cutting speeds, using different air pressure (cooling with tap water).Cutting from low pressure to high pressure, from low speed to high speed step by step.The air pressure is regulated by the filter control valve, and the cutting speed is controlled by the CNC cutting machine.The cutting parts are 100×100 mm square parts.
When the cutting speed is too high and the air pressure is too low, the inclination of the cutting surface is large.This is because the speed is too fast, the arc column is seriously backward, the melting speed of the lower half of the slit can not keep up.So the plane size of the cut parts is small.Large size of lower plane, especially when cutting right-angled parts.Make arcs at the bottom of corners rather than right angles.If the cutting speed is too low, the air pressure is too high, the slag is not easy to remove, and the finish is poor.If the cutting speed is appropriate, the working pressure is too high, the stiffness and smoothness of the arc column are damaged, and the cutting ability is decreased.Poor cutting finish.Therefore, cutting different thickness of steel plate, it is necessary to reasonably choose different cutting power, cutting speed and working air pressure, in order to get the best cutting effect.
According to the test results of four different power machines, the optimal cutting parameters of different thickness steel plates with different power cutting machines are obtained.According to these data we in some manufacturers for practical application of cutting, the effect is very good, cutting quality greatly improved.
3. The conclusion
As we know, there are many factors affecting the quality of CNC plasma cutting machine cutting, in addition to the above mentioned several parameters, as well as cutting process, cutting method, electrode nozzle quality and other factors.But in the actual cutting process.As long as you cut according to the best cutting parameters provided above and control the cutting speed, working air pressure and cutting torch, you can meet the requirements of cutting quality.When cutting voltage and cutting current are stable, the service life of electrode and nozzle can be doubled.
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