Regardless of the size, shape, and location of plastic molds, we must strive for accuracy. Manual manufacturing can no longer meet the requirements for the production of mold parts, and we must rely on digitalization. Among them, the application of CAM technology is the most common, and the implementation effect is good, which greatly improves the design quality and efficiency of modern plastic molds, and opens up a broad market space for the industry.
1 Application of CAM technology in modern mold design and manufacturing
1.1 CAM technology based on concurrent engineering
Concurrent engineering (CE) is a new production management model based on parallel and integrated thinking. It integrates the product design and manufacturing process, so that the functions of each organic component of the product can be parallel and cross. This is obviously different from the traditional serial serial management mode. Based on CE-based CAM technology, the entire production process is divided into three groups: computer-aided design (CAD), computer-aided engineering (CAE), and computer-aided manufacturing (CAM). Each group discusses and tests their work in advance, and collaborates with Other groups communicate with each other to avoid design and production defects at the initial stage, shorten product development time, and reduce production costs, so that enterprises have a more competitive market advantage. Compared with the traditional CAM technology, it is based on CE and puts more emphasis on the integration of real-time information exchange, sharing and data management function modules [1]. Plastic molds have complex curved surfaces and high accuracy requirements. In the traditional serial production management, the design, manufacturing, and inspection are carried out separately. Because the information cannot be shared, the connection between the three is neglected, so that the product cost and efficiency cannot meet expectations. Claim. Therefore, when designing and manufacturing plastic molds, it is necessary to rely on mathematical models to build a relationship between process parameters and manufacturing costs.
1.2 CAM technology based on retrograde engineering
Reverse engineering (RE) relies on reverse analysis thinking to reproduce the finished product design technology, clarify the product process, organizational structure, etc., on this basis, innovative product design. The original profiling method refers to referring to the mold entity to carry out profiling modeling and processing, and then to be corrected by the worker. Whether this kind of processing method is accurate is affected by the skill level of workers. The profiling process cannot be formed at one time, the processing is difficult, the technical requirements are high, the efficiency is low, and the cycle is long. It is gradually replaced by CAM technology based on retrograde engineering. The process is mainly composed of the following five links: preferably 3D laser scanner, coordinate measuring device, etc. to measure the physical prototype; use the geometric modeling combination to simulate the digital result of the above physical prototype, and divide it in geometric units; in CAD In the software, the segmented geometric 3D data is imported, the first simulation modeling work is carried out, and the physical prototypes are compared; after the CAD model data is corrected, the physical manufacturing is performed in CAM. Compare and fit the new model and the physical prototype, and make the second correction. Repeat the above steps several times until the fitting is successful. After obtaining the final version of the 3D model, it is applied to production and construction work [2]. In the design and manufacture of new molds, RE-based CAM technology is applied. Due to the complexity of some mold prototypes, 3D coordinate measuring devices can be used to test their important interfaces and boundary shapes. Finally, take advantage of the CAM software to generate curved surfaces, holes, curling, etc. in the computer, and finally generate thin walls to complete the 3D modeling work. Take advantage of CAM mainstream software to simulate and fit this model. If the fitting data does not conform to the standard, it needs to be modified many times, and the rough prototype, tool type, and milling method are adjusted until the fitting data meets the standard. In addition to improving the quality of mold manufacturing, the production cycle is also shortened, and the cost and risk are relatively low.
1.3 CAM technology based on knowledge engineering
Knowledge Engineering (KBE) is based on artificial intelligence theory to solve difficult problems. Its essence is an expert system constructed on the basis of a huge knowledge system. There are many database modules involved in this process, which takes advantage of artificial intelligence technology to simulate expert analysis, decision-making, judgment, etc. to complete related design and manufacturing work. Taking the decision-making system as an example, it can set cutting parameters and debug CNC machine tools. It completes data induction and inference work, combines processing objects, materials, and positions, infers process parameters such as tool and speed, and improves the efficiency of CNC programming. Avoid duplicate issues. It is also possible to integrate expert experience in the form of a knowledge template, based on which, design and arrange complex formulas and procedures. Under the guidance of the existing template, process complex mold parts, shorten the processing time, and control the processing process. In the final manufacturing process, the best tool and milling method are selected, and after the parameter processing is completed, the data machine tool smoothly executes the relevant commands. In addition, the post-processor must be installed to detect the generation of new CNC codes to make it more accurate. After the verification is correct, enter the relevant code in the CNC machine tool to participate in the manufacturing. CAM technology based on knowledge engineering, based on rich knowledge materials, select the best mold processing technology, perform numerical control programming, make the development process present digital and intelligent features, and give enterprises more advantages. Some molds are more complex, and they can be simplified with the help of expert systems.
