Efficiency and quality in Edgecam mold processing

  • Detail

Efficiency and quality in Edgecam mold processing

the field of mold processing cannot be separated from CAM software, not only because the complex surface cannot be completed by manual calculation, but also because the key factor is to improve the measurement accuracy, stable operation, convenient maintenance quality and processing efficiency of the new electrical control system produced in internal mining. Making full use of cam platform is one of the most effective means. At present, we have seen the mutual promotion between cam and mold processing. At the initial stage of the development of CAM software, we focused on solving the problem of "can" and "can't". Now we are crossing this stage, and put forward higher requirements for processing efficiency and product quality. With the diversification of machining means and the rapid development of numerical control equipment, new requirements are put forward for the application scope of CAM software. Here we will analyze how to better apply CAM software through improving efficiency and quality in mold processing

in mold processing, due to the characteristics of long processing time, high added value of products and small batch of single pieces, the efficiency in mold processing has become the focus of attention. Because the material removal rate per unit area is almost the same no matter what machining path is selected in finishing, the most obvious effect is to effectively shorten the rough machining time. In order to create a good cutting condition for finish machining, rough machining should remove materials as much as possible to ensure uniform allowance. In general, in the rough machining process, to improve efficiency, we should use larger diameter tools as much as possible, and then use smaller diameter tools for residual material processing. In this way, flexible residual material processing means are needed to select cutting tools from large to small for layered and partitioned processing. For example, Edgecam provides sub level cutting, scrap processing and other means to flexibly meet this demand. Sub level cutting refers to a way to refine the larger residual steps on the surface of the profile after rough machining with a large cutting depth with the same tool. This way can effectively improve the machining efficiency compared with directly using a smaller diameter tool to form a rough machined profile at one time. In addition, when using scrap rough machining, when using a small-diameter tool to process the area that the previous large-diameter tool failed to process, the scrap of the previous large-diameter tool can be automatically identified and a tool path can be generated. In the process of scrap machining, sub level cutting or a limited machining area can also be selected according to the situation. These two methods effectively ensure the high quality and efficiency of the tool path generated by rough machining. From the following two processing processes of actual processing moulds, we know that the proportion of material removal of rough machining in mold processing is far greater than that of finish machining; Therefore, to improve machining efficiency, we should first optimize the rough machining process. Secondly, in the whole process of mold processing, the time spent on programming is also a link that should be paid attention to

in the process of programming, we spend time mainly in two aspects: one is the improvement of the model, including the repair of the model and the generation of auxiliary lines and surfaces; The second is the calculation time of generating tool path. Nowadays, CAM software is emerging in endlessly, and the classification methods are relatively diverse. Drying conditions: 110 ⑴ 20 ℃ and 8 hours. Here, the software is classified from the perspective of surface processing and solid processing. The reason is that the classification of cam from the perspective of the type of model being processed is the most essential and core entry point. At first, all CAM software takes surface machining as the core, and generates tool paths by calculating many surface patches that make up the model. In the late 1990s, with the rapid development of 3D solid CAD, many CAM software can program the solid model, but the basis for calculating the tool path is not the solid model itself, but the elements such as points, lines and surfaces extracted from the solid model. Therefore, it is still surface machining in essence, and it is machining solid at best. Solid machining refers to the generation of tool paths based on solid models. Most of these CAM software appeared after 95 years. After 2000, with the development of computer hardware performance and windows platform, CAM software has developed rapidly. For example, Edgecam and camworks now. The characteristic of this kind of software is that the whole process from CAD to cam is completely based on the solid model, and there is no model conversion and data loss, so there is no need to repair the model. It can not only effectively avoid errors and omissions caused by artificial repair model, but also greatly save this part of time. However, because the amount of information of solid model itself is more and more perfect than that of surface model, the amount of calculation also increases correspondingly. Choosing an effective algorithm can solve this problem. For example, we did some tests with Edgecam, and were surprised to see that the calculation time for the solid model has been substantially improved through the optimization of the algorithm. The following is a comparison chart, from which we can see that the calculation time of solid model and surface model under the same conditions has been almost the same, or even exceeded (see Figure 1)

here we see a very interesting phenomenon. In some cases, the calculation time of surface model is more than that of solid model, which is related to the complexity of surface model construction and the size of the model. Taking the medium-sized model as an example, when we calculate the tool path based on hundreds of surface patches that make up the model, it takes some extra time to deal with the surface boundary; For the solid model, the boundary processing is much easier, so it saves a lot of computing time, which is the reason for this phenomenon. In addition, during the update of Edgecam version, we can also see the continuously improved computing performance. Through the horizontal comparison of the same processing methods in different versions, we can also see this change (see Figure 2)

the mold surface quality in mold processing is the core of the whole set of molds. Therefore, how to improve the quality of surface processing is the top priority to improve product quality

selecting reasonable processing parameters and tools is an important link. Within the allowable feed and rotation speed range of the machine tool, it is very important to select reasonable processing parameters according to the performance of the processed materials and the hardware equipment such as machine tools. For example, when finishing the profile of a brass electrode (see the figure below), we use an end mill with a diameter of 2mm, and the speed used in processing is 12000 rpm. The feed speed is 2000mm/min. Even if the tool path is set very closely, the surface quality formed is still not ideal. When the spindle speed is reduced to 6000 rpm, the surface quality of the machined surface is very good. The reason is that the influence of tool vibration on the formation of surface quality in the finishing process has far exceeded the influence of tool path on surface quality. Therefore, in the processing process, the process factors that need to be considered are not only limited to the processed materials and tools, but also need to consider the impact of these non negligible factors, including tooling, machine tools, etc

in addition to selecting reasonable machining parameters, the density and style of tool path are two key factors that determine the quality of profile in the process of programming. Theoretically, we can obtain better surface quality by encrypting the tool path, but with the encryption of the tool path, the processing time will be extended and the processing efficiency will be reduced. In the process of finishing the profile, if the density of the tool path is too large, the cutting amount of each tooth of the tool is too small, and the machining effect is not ideal. Therefore, the density of the tool path is not the smaller the better. It is very critical to choose according to the actual situation. The style of tool path is determined by the processing strategy of programming software. Each cam software has a variety of processing strategies to generate tool path. The scope of each processing strategy and the style of generating tool path are different. Through the combination of different processing strategies, efficient and high-quality tool path style can be obtained. For example, the tool path generated by the machining method of parallel cutting is loved by programmers because of its high stability and controllability. However, the effect of parallel cutting tool path is not very good for the processing of proportional control element domain, which can meet the requirements of most engineering testing industry in steep areas. Generally, there are two ways to deal with it. One is to avoid such a situation. We can identify and avoid the steep areas to generate tool path through the setting of processing parameters, and the steep areas can be processed by other processing paths. Another method is to change the cutting direction for steep areas. These two methods are both means to improve the shortcomings of parallel cutting path

in a word, for the efficiency and quality in the process of mold processing, we should not only consider the selection and use of machine tools and cutters, but also give in-depth understanding and understanding from the perspective of the application of CAM software. We should not only stop at making products, but also start from a faster and better angle to obtain greater product added value and production efficiency. (end)

Copyright © 2011 JIN SHI