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Views: 2 Author: Site Editor Publish Time: 2022-04-29 Origin: Site
Introduction: Metal pipes are widely used in aircraft manufacturing, construction machinery, automobile industry, petrochemical industry, agricultural and animal husbandry machinery and other industries. Due to the different application scenarios, different shapes and sizes of parts need to be processed to meet the needs of different industries. Laser processing technology is especially suitable for the processing of various metal pipes. The tube laser cutting system has the characteristics of high flexibility and high automation, and can realize the production mode of small batch and many varieties of different materials.
What are the key technologies of laser cutting system for pipe?
Guiding light focusing system：
The function of the light focusing system is to guide the laser beam output by the laser generator to the cutting head of the focusing light path. For laser cutting pipe, to get high quality slit, it is necessary to focus the beam spot diameter is small, high power. This allows the laser generator to perform low - order mode output. When laser cutting pipe, in order to obtain a relatively small beam focusing diameter, the transverse mode order of laser is minor, and it is best to be the basic mode. The cutting head of the laser cutting equipment has a focusing lens. After the laser beam is focused through the lens, it can obtain a smaller focused light spot, so that high-quality pipe cutting can be carried out.
Cutting head trajectory control：
In pipe cutting, the processed pipe belongs to the space curved surface, the shape is more complex, if using conventional methods processing programming has the certain difficulty, which requires the operator according to process requirements, select the correct processing path and appropriate reference point, using the numerical control system to record the axial feed and reference point coordinates, Then the coordinate values of the machining process are recorded and the machining program is generated by the spatial linear and circular interpolation functions of the laser cutting system.
Automatic control of laser cutting focus position：
How to control the focus position of laser cutting is an important factor affecting the cutting quality. It is one of the key technologies of laser cutting pipe to keep the vertical direction of focus relative to workpiece surface unchanged by automatic measurement and control device. Through the control of laser focus position and the integration of laser processing system linear axis (X-Y-Z), the movement of laser cutting head is more light and flexible, and the position of the focus can be well known, to avoid the cutting head in the process of processing and cutting pipe or other objects collision.
Influence of main process parameters
1.Influence of optical power
For continuous wave output laser generator, the size of laser power will have an important impact on laser cutting. Theoretically speaking, the higher the laser power of laser cutting pipe equipment, the higher the cutting speed can be obtained, but combined with 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 also changes, which will affect the focus of the laser beam. In actual processing, we often choose less than the maximum power, so that the focus to obtain the highest power density, so as to ensure the efficiency of the whole laser cutting and cutting quality.
2.Impact of cutting speed
Laser cutting pipe must ensure that the cutting speed in a certain range to obtain better cutting quality. If the cutting speed is too slow, too much heat will accumulate on the surface of the pipe, the heat-affected zone becomes larger, the cutting seam becomes wider, and the hot melt material discharged burns the incision surface, making the incision surface become rough. When the cutting speed increases, the average circumferential slit width decreases, and the smaller the pipe diameter is, the more obvious this effect is. With the acceleration of cutting speed, the time of laser action is shortened, the total energy absorbed by the pipe becomes less, the temperature at the front of the pipe decreases, and the width of the slit is reduced. If the cutting speed is too fast, the pipe will not be cut or cut continuously, thus affecting the whole cutting quality.
3.The effect of pipe diameter
When laser cutting pipe, the characteristics of pipe itself will also have a great influence on the processing process. For example, the size of round pipe diameter has a significant impact on the processing quality. Through the study of laser cutting thin-wall seamless steel pipe, it is found that laser cutting pipe equipment in the case of constant technological parameters, increasing the diameter of the slit width will also increase.
4.Type and pressure of auxiliary gas
Compressed air or inert gas (e.g. nitrogen) can be used as auxiliary gas for cutting non-metallic and partial metal tubing, while reactive gas (e.g. oxygen) can be used for most metal tubing. After determining the type of auxiliary gas, it is very important to determine the pressure of auxiliary gas. When cutting the pipe with small thickness of pipe wall at a higher speed, the pressure of auxiliary gas should be increased to prevent slagging in the incision. When the thickness of the cutting pipe wall is large or the cutting speed is slow, the pressure of the auxiliary gas should be appropriately reduced to prevent the pipe from being cut or continuously cut.
The position of beam focus is also very important when laser cutting pipe. When cutting, the focus position is generally on the surface of the cutting pipe fitting. When the focus is in a better position, the slit is the smallest, the cutting efficiency is the highest, and the cutting effect is the best.
