It is one of the main cutting devices in CNC cutting equipment. During the cutting process, there are often issues such as poor cutting results and large cutting seams. There are many factors that can cause these problems. Cutting oxygen flow rate, purity, oxygen flow shape, pressure, preheating flame power (referring to the amount of work done by the object per unit time), composition, properties, surface state, and initial temperature of the metal being cut can all affect the final cutting effect;

Two factors that have a significant impact and are worth noting are the influence of thermal expansion during flame cutting and the influence of flame cutting path selection. There are many things to pay attention to when using a CNC flame cutting machine, and using an oxygen tube is one of the things that needs to be noted. Below are some precautions for the oxygen tube of a CNC flame cutting machine, which will be briefly explained to users. However, in the actual cutting process, many factors can be artificially controlled to have a low impact on the effect.

In the actual cutting process, especially when cutting parts with CNC flame cutting machines, the temperature of the steel plate is not high at the beginning of cutting, which is similar to the indoor temperature, but the cutting speed of the parts is very fast, especially for very small parts. After cutting a part, the temperature may be the same as before cutting, or only locally heated, and the size of the cut part is still relatively accurate. However, as the cutting time increases and the number of parts increases, there is continuous heat output, and the temperature of the steel plate will also continue to rise, resulting in thermal expansion. At this time, a single-sided thermal expansion compensation amount △ t needs to be added to the slot compensation k to change the cutting trajectory, so that the size of the parts will not deviate when cutting again. If not replenished, the thermal expansion of the steel plate will increase, and the cutting trajectory will not change at the same time. The dimensional deviation of the cut parts will also increase. However, supplies should be provided according to the actual situation. For parts with similar length to diameter ratios, the expansion in all directions is basically the same, and only a single-sided thermal expansion compensation amount △ t needs to be added to the slot compensation k. For those with large differences in length to diameter ratios and inconsistent expansion amounts in various directions, not only should a single-sided thermal expansion compensation amount △ t be added to the slot compensation k, but also a single-sided thermal expansion compensation amount △ t1 in the short diameter direction should be added to the slot compensation k. At the same time, the total difference between the thermal expansion compensation amounts in the long diameter direction and the short diameter direction should be directly added to the cutting program to ensure the dimensional accuracy of the cut parts.

Inexperienced employees may not be familiar with controlling the thermal expansion of steel plates. Physical cooling methods such as circulating cooling water and antifreeze coolant can be used to cool and reduce the temperature, control the thermal expansion of steel plates, and ensure the accuracy of the dimensions of the parts cut by the CNC flame cutting machine. The oxygen pipe of the CNC flame cutting machine is red and can only be used for oxygen and cannot be used for other gases; Acetylene pipes are black, and it is prohibited to switch between two types of rubber pipes. However, this method has a limitation, which is that it can only be used when the hardening tendency of the steel plate is not significant, or when trace hardening has little impact on product quality.

The choice of cutting path will also have an impact on the size of the cut parts. Numerical control is a machining method that uses the heat of high-temperature plasma arc to locally melt (and evaporate) the metal part at the cutting edge of the workpiece, and uses the momentum of high-speed plasma to remove the molten metal to form the cutting edge. Compared with traditional plasma cutting machines, it has the characteristics of high efficiency, high precision, and high stability, making it suitable for large-scale production and processing of precision and complex products. Poor selection of cutting path can affect the accuracy of cutting parts. The connection stiffness between the part and the steel plate also affects the cutting size and accuracy of the part.

When using a CNC flame cutting machine for cutting, the influence factors of thermal expansion and cutting path force should be considered based on the actual situation, the thickness of the processed material, and the correct cutting method should be used to ensure the accuracy of the cut product and avoid waste. As a high-tech precision instrument, its use in the processing industry is not very extensive.