Quality improvement and efficiency enhancement of fiber laser cutting machine in thin plate processing
In the processing of sheet metal parts in the mechanical industry of fiber laser cutting machines, the method of discharging the parts on the sheet is the key to the material utilization rate and the production cycle. The traditional layout method is inefficient, labor-intensive and time-consuming. With the help of a computer, finding a better layout of parts and automatically generating a numerical control program can not only improve the utilization rate of materials, but also greatly shorten the production cycle. For this reason, under the Windows platform, we use BorlandC++4 to research and develop a set of graphics automatic programming system suitable for CNC laser cutting processing. This system mainly includes parts drawing editing, part drawing preprocessing, layout and NC program generation.
Part drawing editing, this system uses its development tool ADS on AutoCADR12 platform to carry out secondary development, completes the function of equation curve, list curve input and list curve fitting, etc. The output is DXF Parts drawings stored in file format.
Part drawing preprocessing part drawing sorting. In the DXF file, there is no certain order in the arrangement of the edges of the part drawing, and the edges of the part drawing are required to be arranged in a certain order during layout. Therefore, the system processes each edge of the part drawing, including sorting, judging whether it is in order or reverse order, judging whether it is an outer ring or an inner ring, and so on.
Laser beam radius and part contour nesting pretreatment. In the laser cutting process, due to the existence of the laser beam radius, it cannot be processed directly according to the outer contour of the part, and the laser beam radius must be compensated. This system uses the C tool radius compensation method to approximate the outer contour of the part. 2.3 Obtaining the minimum circumscribed rectangle of the part Rotate the part and obtain the area of u200bu200bthe circumscribed rectangle of the part at each angle. The smallest area is the minimum circumscribed rectangle. By obtaining the smallest circumscribed rectangle of the part, two optimal directions of layout can be found.
The newly purchased laser cutting machine is mainly used in the processing of sheet metal parts and medium and heavy plate products. Its advantages are a wide range of applications, high processing accuracy, and different materials and thicknesses of metal and non-metal. Both can be processed, especially in curve processing and small batch processing of special-shaped parts. Due to the high value of fixed assets of laser cutting machines, how to improve the production efficiency and processing quality of laser processing and reduce production costs during the use process is an important link that needs to be resolved on site. The L11K laser cutting parts processed by the company for the professional automobile sheet supporting company are materials for car doors. After the shape is cut by laser, the parts are laser welded with high-strength sheets of different thicknesses, and then stamped and formed to achieve It can not only reduce the weight of the components, improve the utilization rate of materials, but also meet the requirements of the local strength of the components.
The technical requirements for L11K laser cutting parts are about 4000 pieces per month, with a short delivery time and high product processing accuracy requirements, as shown in Figure 1, where:
⑴The size of the cut piece is larger, 0.65mm×1730mm×910mm, the thickness of the sheet is thin, and it is easy to deform;
⑵The straightness a after cutting is required to be within 0.05mm, Burr b is required to be within 0.03mm;
3 After cutting, the diagonal c is required to be within 1.0mm, and the flatness d is required to be within 1.0mm;
⑷Symmetry e after cutting It is required to be within 0.5mm.
Due to the high complexity of the newly purchased fiber laser cutting machine equipment, especially the control and programming parts, imported parts are used, and the Chinese operating instructions are too simple to write, and no instructions for calling and modifying the corresponding subprograms , In the initial operation of the laser cutting machine, there are many aspects that need to be explored and familiarized in practice.
Through sample trial cutting, statistics on product defects. From the statistics of trial cutting, it can be seen that in the poor quality of L11K laser cutting parts, the proportion of burrs is higher, followed by symmetry, and there is also the problem of low product production efficiency.