Influencing factors of cutting precision of CNC plasma cutter

CNC plasma cutter can cut all kinds of complex shape workpiece, and has the advantages of fast cutting speed, high efficiency, good cutting surface quality, accurate cutting size, small thermal deformation of workpiece and so on. The cutting parts can be directly welded and applied without machining. But CNC plasma cutter is plasma arc cutting, cutting thick plate, compared with oxygen cutting, there are still some defects, mainly reflected in the cutting surface tilt is larger, smooth finish without oxygen cutting good. The main criteria to evaluate the quality of NC plasma cutting are: the inclination of cutting surface, the depth of kerf, the amount of slag hanging, etc.. A high quality cutting surface should be less than 30, the cut depth should be below O.15mm, and less slag, easy to remove. In the condition of voltage and current stability, the factors affecting the quality of cutting, in addition to the electrode and nozzle quality, there are two main reasons: one is the height and stability of cutting nozzle; another is the matching of cutting speed and working pressure.

Cutting head of CNC plasma cutter from the height of the steel plate when the arc voltage control, because of its dynamic positioning precision can reach + 0.013 together, so as to ensure the cutting nozzle and the plate height remains unchanged, so the cutting plane inclination is small and uniform, and a good finish. When using the hand to adjust the height of the cutting edge from the steel plate. Try to cut steel flat, to reduce the number of adjusting cutting torch. To ensure the torch cutting process stability. In this paper, the height of the cutting edge from the steel plate is controlled at 6~8 by manual adjustment

Mm, through the experiment of cutting a series, expounds the cutting speed, working pressure (dirty) (P) and the relationship between cutting quality.

When the cutting speed of CNC plasma cutter 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 seriously backward, melting speed with no cutting part. So the plane size of the cutting parts is small. Under the large dimensions, especially cutting rectangular parts. An arc shape rather than rectangular slot at the bottom corner. If the cutting speed is too low and the air pressure is too high, the slag hanging is serious, difficult to remove, and the finish is poor. If the cutting speed is appropriate, the working air pressure is too high, the stiffness and smoothness of the arc column are damaged, the cutting ability is reduced, and the cutting finish is poor. Therefore, CNC plasma cutter cuts different thickness of steel plate, need to choose different cutting power, cutting speed and working pressure, in order to get the best cutting effect.