CAM software can not be separated from the mold processing field, not only because of the complex model can not be completed by manual calculation, the more critical factor is to improve the quality of products and processing efficiency. Making full use of the CAM platform is one of the most effective means. At present, we have seen the mutual promotion of CAM and mold processing. At the beginning of the development of CAM software, it focused on solving problems that could not be solved. This stage is now being advanced and higher demands are made on processing efficiency and product quality. With the diversification of processing methods and the rapid development of numerical control equipment, new requirements have been put forward for the application of CAM software. Here we analyze how to make better use of CAM software through two angles of efficiency and quality in mold processing.
In the mold processing, due to the characteristics of long processing time, high product added value, and small batch size, the efficiency in mold processing has become the focus of attention. In the finishing process, regardless of the machining trajectory selected, the material removal rate per unit area is almost the same. Therefore, the most obvious effect is to effectively shorten the rough machining time. In order to create a good cutting condition for finishing, roughing should remove material as much as possible to ensure a uniform balance. In general, in the roughing process, to increase the efficiency, it should be possible to use a larger diameter tool, and then use a small diameter tool for residual material processing. Such a large-to-small selection of tools for hierarchical division processing requires flexible residual material processing methods. For example, Edgecam provides sub-level cutting, residual material processing and other means can flexibly meet the needs of this area. Sub-level cutting refers to a method of thinning a large residual step on the surface of a profile after rough cutting with the same tool, and this method is used to form a rough one-time machining with a smaller-diameter tool. Compared with the processing surface, it can effectively improve the processing efficiency. In addition, when using residual material roughing, when using a small-diameter tool to machine an area where the previous large-diameter tool failed to machine, it can automatically identify the residual material of the previous large-diameter tool and generate a tool path. Select sublevel cutting or a limited machining area. These two methods effectively ensure that the tool path generated by rough machining is of high quality and high efficiency. We learned from the following two actual machining tools that the amount of material removed for rough machining is much greater than that of precision machining in the mold processing; therefore, the first step in improving the machining efficiency should be during the roughing process. optimization. Second, during the entire process of mold processing, the time spent on programming is also a concern.
In the programming process, we spend time mainly in two aspects, one is the perfection of the model, including the repair of the model, the auxiliary line and surface generation; the second is to generate the tool trajectory calculation time. Nowadays, CAM software emerges in an endless stream and the classification methods are relatively diverse. Here, we classify the software from the point of view of surface processing and solid processing. The reason is that classification of CAM from the perspective of the model being processed is the most essential and essential point of entry. At first, all the CAM software was based on surface processing, and the tool trajectory was generated by calculating on the basis of numerous surface patches constituting the model. In the late 1990s, with the rapid development of 3D solid CAD, many CAM software can program the solid model. However, the basis for calculating the tool path is not the solid model itself, but the point and line surface extracted from the solid model. Therefore, it is still essentially curved surface processing, and at best it is a processing entity. Physical processing refers to the generation of tool trajectories using the physical model as the basis for calculation. Most of these CAM softwares appear after 95 years. After 2000, with the development of computer hardware and the Windows platform, CAM software can develop rapidly. For example, the current Edgecam, CAMworks and so on. The feature of this type of software is that from the CAD to the CAM, based entirely on the solid model, there is no model conversion and data loss, so there is no need to repair the model. Not only can it effectively avoid errors and omissions caused by human patching models, but it can also greatly save this part of time. However, since the amount of information in the physical model itself is more complete than the surface model, the amount of calculations is correspondingly increased. Selecting an effective algorithm can solve this problem. For example, we used Edgecam to do some tests and we were pleasantly surprised to see that the optimization of the algorithm has resulted in a substantial increase in the computation time for the solid model. The following is a comparison chart, we can see from it, the calculation time of the solid model under the same conditions and the calculation time of the surface model have been almost the same, or even exceeded (see Figure 1). Here we see a very interesting phenomenon. In some cases, the calculation time of the surface model is actually more than the calculation time of the solid model. This is related to the complexity of the surface model construction and the size of the model. We take the medium-sized model as an example. In the process of calculating the tool path, when the hundreds of surface patches constituting the model are used as calculation basis, it takes some extra time to process the boundary of the surface. For the physical model, The boundary processing is much easier and therefore saves a lot of computing time. This is the reason for this phenomenon. In addition, we can see continuously improved computational performance during the Edgecam version update. We can also see this change by comparing the same processing methods in different versions (see Figure 2). 
Figure II
The surface quality of the mold processing is the core of the whole mold. Therefore, how to improve the quality of profile processing is the top priority in improving product quality.
Choosing reasonable processing parameters and tools is an important part. Within the allowable feed and speed range of the machine tool, it is very important to select reasonable processing parameters for the profile according to the performance of the material being processed and the hardware equipment such as the machine tool. For example, when finishing a brass electrode profile (see the figure below), we use an end mill with a diameter of 2 mm. The machining speed is 12,000 rpm. The feed rate is 2000mm/min. Even if the tool path is set very dense, the resulting surface quality is not ideal. When the number of spindle revolutions is reduced to 6000 rpm, the machined surface quality is very good. The reason is that the effect of tool chatter in the finishing process on the formation of the profile quality has far exceeded the influence of the tool path on the profile quality. Therefore, in the process of processing, the technological factors that need to be considered are not only limited to the materials and tools being processed, but also need to consider the influence of such non-negligible factors as tooling and machine tools.
Figure 3
In addition to choosing reasonable processing parameters, the density and pattern of the tool path during the programming process are the two key factors that determine the quality of the profile. Theoretically, we can obtain better surface quality by encrypting the tool path, but as the tool path is encrypted, the processing time is extended and the processing efficiency is reduced. In the process of finishing the profile, if the density of the tool path is too large, the cutting amount per tooth of the tool is too small, and the effect produced is not ideal, so the density of the tool path is not as small as possible, according to the actual It is critical to make trade-offs. The style of the tool path is determined by the programming strategy of the programming software. Each CAM software has multiple machining strategies for generating tool paths. The scope of each machining strategy and the style of the generated tool path are different. The combination of strategies can achieve efficient and high-quality toolpath styles. For example, the tool path generated by the parallel line cutting method is favored by programmers because of its extremely high stability and controllability. However, the tool trajectory cut in parallel is not very good for the processing of steep areas. In general, there are two ways to deal with it. One is to avoid such a situation. We can identify and avoid the parameters through the setting of processing parameters. Steep areas generate tool paths, and steep areas can be processed using other machining paths. Another approach is to take a change in the cutting direction of steep areas for processing. Both of these methods are the means to perfect the disadvantages of the parallel line cutter.
In short, for the efficiency and quality of the mold processing process, not only the selection and use of machine tools and tools should be considered, but also from the application of CAM software to give a deep understanding and understanding, can not just stay in the product to do, It is also necessary to proceed from a faster and better perspective to obtain greater product added value and production efficiency.
Figure 1