Metal tubes are widely used in aircraft manufacturing, engineering machinery, automobile industry, petrochemical industry, agricultural machinery and other industries. Due to different application scenarios, metal tubes need to be processed into parts of different shapes and sizes to meet the needs of different industries. We mentioned earlier that the advanced laser processing technology is particularly suitable for processing various metal tubes. Nowadays, the tubular laser cutting machine is developing towards the direction of high flexibility and high automation, and can finally realize the production mode of different materials and small batches. Therefore, by understanding and breaking through the key technologies of tubular laser cutting machine, system equipment suppliers can have a broader development prospect in the field of metal tube cutting.

What are the key technologies of tube laser cutting machine?

Light guide plate focusing system

The function of the light guide focusing system is to guide the beam emitted by the laser generator to the cutting head of the focusing optical path. For laser cutting tubes, high-quality slits are needed to focus beams with small spot diameter and high power. This allows the laser generator to perform low order mode output. In the process of laser cutting pipe, in order to obtain a relatively small beam focusing diameter, the laser should have a small transverse mode order, preferably the basic mode. The cutting head of the laser cutting equipment is equipped with a focusing lens. After the laser beam is focused by the lens, a small focus can be obtained, so that high-quality pipe cutting can be performed.

Cutting head trajectory control

In pipe cutting, the pipe to be machined belongs to the space surface, and the shape is relatively complex. If the routine method is used to process the program, there will be some difficulties, which requires the operator to select the correct processing path and appropriate reference point according to the processing requirements. The CNC system records the feed conditions of each axis and the coordinate values of the reference point, and then records the coordinate values of the processing process through the spatial straight line and arc interpolation function of the laser cutting system, and generates the processing program.

Automatic control of laser cutting focus position

How to control the focus position of laser cutting is an important factor affecting the cutting quality. One of the key technologies of laser pipe cutting is to continuously measure the focus relative to the workpiece surface through automatic measurement and control equipment. By integrating the control of the laser focus position with the linear axis (XYZ) of the laser processing system, the laser cutting head can move more lightly and flexibly, and the focus position can be well understood to avoid collisions between laser heads. Cutting heads and tubes or other objects during machining.

What are the key technologies of tube laser cutting machine?

Influence of main process parameters

1. Laser power influence

For continuous wave output laser generator, laser power has an important impact on laser cutting. Theoretically, the higher the laser power of the laser pipe cutting equipment is, the higher the cutting speed will be. However, considering the characteristics of the pipe itself, the maximum cutting power is not the best choice. When the cutting power is increased, the mode of the laser itself will change, which will affect the focusing of the laser beam. In actual processing, we often choose to achieve the highest power density of the focus when the power is less than the maximum power, so as to ensure the efficiency and cutting quality of the entire laser cutting.

2. Effect of cutting speed

The laser cutting of pipes must ensure that the cutting speed is within a certain range to obtain better cutting quality. If the cutting speed is slow, the pipe surface will accumulate too much heat, the heat affected zone will become larger, the gap will become wider, and the discharged hot melt material will burn the cutting surface, resulting in rough section. When the cutting speed is increased, the average circumferential gap width of the pipe becomes smaller, and the smaller the diameter of the cutting pipe, the more obvious the effect is. With the increase of cutting speed, the laser action time is shortened, the total energy absorbed by the pipe is reduced, the temperature at the front end of the pipe is reduced, and the width of the slit is reduced. If the cutting speed is too fast, the pipe cannot be cut continuously or continuously. This will affect the overall cutting quality.

3. Impact of pipe size

When the pipe is cut by laser, the characteristics of the pipe itself will have a great impact on the processing. For example, the size of the pipe diameter has a significant impact on the processing quality. Through the research of laser cutting thin-wall seamless steel pipe, it is found that the laser cutting pipe equipment increases the pipe diameter continuously when the process parameters are unchanged. The width will also increase

4. Type and pressure of auxiliary gas

When cutting non-metallic pipes and some metal pipes, compressed air or inert gas (such as nitrogen) can be used as auxiliary gas. For most metal pipes, reactive gas (such as oxygen) can be used. After determining the type of auxiliary gas, it is also important to determine the pressure of auxiliary gas. When cutting pipes with small wall thickness at a higher speed, the pressure of auxiliary gas shall be increased to prevent slag from appearing in the gap. When the thickness of the cutting pipe wall is large or the cutting speed is slow, the auxiliary gas shall be appropriately reduced. The pressure is to prevent the pipe from being cut.

When laser cutting tubes, the position of the beam focus is also important. When cutting, the focus position is usually on the surface of the cutting tube. When the focus is in a good position, the gap is the smallest, the cutting efficiency is the highest, and the cutting effect is the best.