Solutions to abnormal sparks when cutting mild steel
This situation will affect the quality of the cut surface finish of the part. At this time, when other parameters are normal, the following conditions should be considered: the nozzle of the laser head is worn out, and the nozzle should be replaced in time. In the case of no new nozzle replacement, the pressure of the cutting working gas should be increased; the thread at the connection between the nozzle and the laser head is loose. At this time, cutting should be suspended immediately, check the connection status of the laser head, and rethread.
Selection of puncture point in laser cutting processing
The working principle of the laser beam during laser cutting processing is: during the processing, the material forms a pit in the center after continuous laser irradiation, and then the molten material is quickly removed by the working airflow coaxial with the laser beam to form a hole. This hole is similar to a threading hole for wire cutting. The laser beam uses this hole as the starting point for contour cutting. Generally, the direction of the laser beam in the flying optical path is perpendicular to the tangent direction of the cut contour of the processed part.
Therefore, from the time when the laser beam begins to penetrate the steel plate to the part contour cutting, its cutting speed will change greatly in the vector direction, that is, 90 ° rotation in the vector direction, and the tangent line perpendicular to the cutting contour will change. The direction turns to coincide with the tangent to the cutting contour, that is, the angle with the tangent to the contour is 0 °. In this way, a relatively rough cutting surface will flow down the cutting section of the processed material, which is mainly due to the rapid change of the vector direction of the laser beam in the movement in a short time. Therefore, pay attention to this situation when using laser cutting to process parts. Generally, when the design part has no roughness requirements for the surface cutting fracture, the manual cutting process can be omitted during the laser cutting programming, and the control software can automatically generate puncture points; however, when the design has a higher roughness on the cutting section of the part to be processed When required, we must pay attention to this problem. Usually, we need to manually adjust the starting position of the laser beam when programming the laser cutting program, that is, manual control of the puncture point. It is necessary to move the puncture point originally generated by the laser program to a reasonable position required in order to meet the requirements for the accuracy of the surface of the processed part.
As shown in Figure 1 above, if this part has accuracy requirements for arcs, when we write a laser cutting program, the cutting start point (puncture point) must be set at A and C, not at B and D. And if this part only requires the accuracy of the straight edge, then when we write the laser cutting program, the cutting start point should be set at B and D, but not A and C.
Similarly, as shown in Figure 2, if the shape design of this part has accuracy requirements for arcs, when we write the laser cutting program, the cutting start point (puncture point) can only be set at D, and if this part is only for the straight edge There is a requirement for accuracy, so when we write the laser cutting program, the cutting starting point (puncture point) can choose any point other than point D.
Laser cutting sheet metal is an advanced manufacturing process technology, which can not only greatly reduce the research and development cycle and mold manufacturing cost, but also improve the quality and production efficiency, which is conducive to improving the technology and equipment innovation of the manufacturing industry. In practical applications, we need to continuously accumulate experience, constantly understand and practice, so that this new technology can make its due contribution to the improvement of our productivity.
