The hottest laser cutting shortens the mold manufa

Laser cutting shortens the mold manufacturing cycle

unlike plastic molds, automotive panel molds have complex processes and various processes. Generally, it needs to go through processes such as drawing, trimming, punching, flanging (shaping), among which the trimming process has the longest cycle. The most direct reason for the long cycle of trimming die is that it takes a lot of time and repeated exploration to determine the trimming line. The traditional edge cutting line exploration method makes the mold manufacturing cycle very long, and the enterprise production cost also increases more. With the increasingly fierce competition in the mold industry, the mold manufacturing period is required to be shorter and shorter, and the mold price continues to decline, which also requires mold enterprises to further reduce production costs, making the use of new methods imminent

3D laser cutting conforms to the urgent needs of the mold industry at present. It can effectively improve the quality of groping for the cutting edge line of automobile panel mold, reduce the number of groping, speed up the process of determining the cutting edge line, and effectively shorten the mold manufacturing cycle

1 laser cutting principle

laser cutting is to use the focused high-power and high-density laser beam to irradiate the workpiece, so that the irradiated material can quickly melt, vaporize, ablate or reach the ignition point, and at the same time, with the help of the high-speed air flow coaxial with the beam to blow away the molten material, so as to realize the cutting of the workpiece. It is a processing technology with high speed, basically no deformation and stable processing quality. Three dimensional laser cutting can be processed according to the changes of products, which fully meets the complex requirements of automotive panel cutting

2 the traditional method of determining the cutting edge line

the cutting edge of the automobile panel cutting die is a large number of Cr12MoV (corresponding to the foreign brand SKD-11) and other alloy steels. These materials are expensive and easy to crack in the improper welding process or multiple welding processes. If it cracks, the inserts will be scrapped. On the one hand, the mold cost will increase significantly with the re purchase and processing, on the other hand, the mold production cycle will also increase accordingly. Therefore, generally, mold enterprises will not take the risk of significantly increasing costs and increasing production cycle to process trimming molds. They will first explore the trimming line for several rounds before processing molds

next, we will briefly introduce the traditional method of determining the cutting line

first, we put a certain amount of manual correction allowance (generally about 2mm) on the theoretical cutting line calculated by CAE software to prepare a two-dimensional marking program, and then put the drawing die punch on the machine tool, and put the drawn product on the punch. We use the prepared marking procedure to mark the product. Because the shape of automobile panel products is complex, and the marking is carried out on an ordinary three-axis machine tool, from the curve, there will be cases where the line cannot be drawn. A good example is shown in Figure 1. Two dimensional scribing is powerless in steep places of the product. At this time, it needs to be supplemented by manual scribing. After marking the line of the product, the worker roughens the unwanted places with flame cutting or coarse sand wheel according to the marking, and then manually repair the workpiece. Next, use the workpiece to debug the flanging (shaping) mold, and finally press out the product. The product shall be inspected by the inspector, and the trimming line shall be adjusted according to the product condition. Finally, change the line according to the test results, re scribe and try the mold again, and repeat this several times

according to the above introduction to the traditional method of determining the edge cutting line, it is not difficult to see that in the process of determining the traditional edge cutting line, the first lineation is inconsistent with the theoretical edge cutting line. In addition, there is manual auxiliary lineation, and the product parts are manually repaired. That is to say, at the beginning, the results we want to get are far from the theory, and each modification is actually not completely based on the last result, It is doomed that we need to repeat several times to get a relatively reliable result; In addition, because each modification requires a lot of manual correction, it is a waste of time, resulting in a long time interval between the last mold test and the next modification, which also increases the pressure of the mold production cycle. In addition, each mold test will not only waste product samples, but also occupy a lot of machine tools and equipment, which is also a challenge to the mold cost control

generally speaking, the biggest shortcomings of the traditional method of determining the cutting line are: manual correction is dominant, there are many human interventions, long cycle, high cost and low quality

3 laser cutting method to determine the cutting edge line

the same as the traditional method, the method of laser cutting to determine the cutting edge line also needs to go through the cycle of programming, cutting, mold testing, detection, line modification, re cutting and mold retry, which all need to occupy the machine tool. There are the following differences:

first, the compiled program no longer leaves manual correction, but a three-dimensional processing program that is completely consistent with the theoretical cutting line, which is directly used to cut products. As shown in Figure 2, it can ensure that the cutting process is always consistent with the actual edge cutting state, and there is no situation that cannot be drawn by two-dimensional scribing. There is no manual intervention in the whole cutting process, which ensures that the products obtained from each processing are consistent with the numerical simulation from the source, so as to reduce the edge cutting line that needs several times of exploration to only 3 to 4 times. Because there is no marking process, it also saves the time of manual cutting. Using laser cutting can reduce the original time of 4 hours (or even more) to manually repair a piece to about 10 minutes, and shorten the original time of several days to determine a product cutting line to only a few hours

second, the product quality obtained by laser cutting is very good, the cutting edge line is smooth, and the appearance quality is far better than that obtained by hand. Figure 3 shows the product obtained by traditional scribing + manual correction. We can see that there is obvious black skin on the edge of the product, and the contour quality is poor. Figure 4 shows the products processed by laser cutting. The surface quality is close to that of the products directly processed by the mold, which is more in line with the actual needs

third, due to the use of special machine tools, it will not affect the production progress of other molds due to the marking of products. It is no longer a simple serial method, which will earn more time and occupy less resources for enterprises to compete

the characteristics of laser cutting method for determining the cutting edge line: cutting fully adapts to the complex changes of panel products, fully simulates the actual mold production situation, does not need manual correction, fast speed, short cycle, and good cutting quality

4 laser cutting programming and processing

unlike general-purpose software, laser cutting software is generally not sold separately, but basically bundled with machine tools. In the laser cutting material performance cutting machine market, the five axis laser cutting machine of NTC company in Japan has an absolute advantage, and they are mainly bundled with peps Pentacut software. The advantage of bundled sales with machine tools is speed accuracy: the relevant data of machine tools have been customized in advance in the software to ensure the authenticity and accuracy of program simulation. At the same time, it also ensures that the program generated by users meets the requirements of machine tools, and eliminates the possibility of machine collision caused by user settings errors. This kind of software is particularly simple and practical

the following describes the laser cutting programming process with peps software

(1) data preparation

peps software can directly read files such as UG, CATIA, Pro-E, DXF, IGS, step and other formats, so we generally do not need to carry out special conversion on the model. It is worth mentioning that the software only recognizes the absolute coordinates of the model when reading the model, while for the automobile model, the absolute coordinates of our general model are the coordinates of the automobile body. Although we can turn the model to the appropriate position through a series of movement and rotation instructions in this software, it is not as fast and intuitive as in UG, CATIA and other software, so it is recommended to convert the relative coordinates of the original model into absolute coordinates

(2) programming and simulation

as mentioned above, because the software is bundled with the machine tool, and all the parameters of the machine tool are preset by the software, after importing the digital analog, we only need to do simple operations to move the product digital analog to the predetermined position (generally the center of the machine tool). Considering that the product may deform in the cutting process, we need to process in a certain order. According to experience, we select the processing elements in the way of hole first, contour first, inner first, outer first. As long as we confirm that the selection is completed, the software will automatically calculate the program. In principle, the software will automatically ensure that it does not cut, collide or exceed the range, but sometimes it needs to be modified manually. However, the software is intelligent and easy to operate, and the program can be modified in a few simple steps

after program calculation, we need to simulate the program. The simulation interface is shown in Figure 5. We can easily locate the cutter axis of the machine tool anywhere

(3) laser cutting processing

Figure 6 shows the product sample, and Figure 7 shows the product sample being cut

5 prospects of laser cutting

although 3D laser cutting machine has not been popularized in China, with the intensification of industry competition, shortening the cycle, improving quality and reducing costs are the only way for mold enterprises to develop. Laser cutting will become the most powerful competitive magic weapon for mold enterprises. (end)