Views:8 Author:heyu Publish Time: 2020-05-22 Origin:Leapion fiber laser cutting machine
In the process of laser cutting, if the focus position is different, the cutting quality will be different. In order to improve the quality of laser cutting machine, it is very important to adjust the focus position of laser cutting machine.
Today, with the rapid development of economy, laser cutting machine has come into people's life quietly. With the continuous improvement of people's material level, especially the continuous refinement of crafts, it is inseparable from the continuous accuracy of laser cutting and carving.
Several key technologies must be mastered and solved in laser cutting machine for parts with high cutting accuracy or large thickness. Focus position control technology is one of them. The main advantage of laser cutting machine is the high energy density of laser beam, so the diameter of focal spot should be as small as possible to produce narrow slit. Because the smaller the focal depth is, the smaller the focal spot diameter is. For high-quality cutting, the effective focal depth is also related to the lens diameter and the cut material. Therefore, the position of the control focus relative to the surface of the material to be cut is very important.
We analyze the cutting focus from the following three aspects: different materials and different requirements
First, the cutting focus is on the workpiece surface:
This mode is also called zero focal length, which is commonly used in the cutting of SPC, SPH, SS41 and other workpieces. When using, the focus of the cutter is close to the workpiece surface. In this mode, the smoothness of the upper and lower surfaces of workpieces is different. Generally speaking, the cutting surface close to the focus is relatively smooth, while the lower surface far away from the cutting focus is rough. This mode shall be determined according to the process requirements of the upper and lower surfaces in practical application.
Second, the cutting focus is in the workpiece:
This is also known as positive focus. When the workpiece you need to cut is stainless steel or aluminum steel plate, the mode of cutting point in the workpiece is often used. However, one disadvantage of this method is that the cutting amplitude is larger than that of the cutting point on the workpiece surface due to the focus principle. At the same time, the cutting air flow required in this mode is larger, the temperature is enough, and the cutting perforation time is slightly longer. So when you choose the material of the workpiece is mainly stainless steel or aluminum lamp with high hardness.
Third, the cutting focus is on the workpiece:
In this way, we also become negative focus, because the cutting point is not located on the surface of the cutting material or inside the cutting material, but above the cutting material. This method mainly uses materials with high cutting thickness. In this way, the focus is located above the cutting material, mainly due to the large cutting range required by the thick plate, otherwise the oxygen delivered by the nozzle will easily lead to insufficient cutting temperature drop. However, one disadvantage of this method is that the cutting surface is relatively rough and not very practical for cutting with high precision.
As the laser power density has a great influence on the cutting speed, the choice of lens focal length is also an important issue. After the laser beam is focused, the spot size is directly proportional to the focal length of the lens. After the beam is focused by the short focal length lens, the spot size is very small, and the power density at the focal point is very high, which is very beneficial to the cutting of materials. However, its disadvantage is that the adjustment margin of the focal depth is very short, which is generally applicable to the high-speed cutting of thin materials. Because of the wide focal depth of the long focal lens, as long as it has enough power density, it is suitable for cutting thick workpiece.
The adjustment of focus is difficult for the operator of laser cutting machine, so we should learn more. When the focus is in the best position, the cutting seam is the smallest and the efficiency is the highest. The best cutting speed of the fiber laser cutting equipment can obtain the best cutting results. More information
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