Some Key Technologies Of Product Digital Design Of Precision Plastic Injection Moulding Equipment And The Development Of An Integrated Platform

In recent years, with the fast development of the automobile, electronics, IT, and appliances, people raise more and more requirements of the precision, form, function, and cost of the plastic products. The proposed requirements are based on the development of product digital design of precision plastic injection moulding equipment. Based on the precision plastic injection moulding equipment, we studites some key technologies of product configuration, variation and simulation in digital design and develops an integrated platform of product configuration, variation and simulation to achieve the fast respond of design of product demand-driven. In practice, the advanced integrated platform of product configuration, variation and simulation is used in the design and simulation of new large dual-platen mold closing mechanism and twin toggle three links and five hinges diagonal type mold closing mechanism, and the effects are good.The structure of this dissertation is as follows:Chapter 1 analyses the functions and the trends of precision plastic injection molding equipment and propses the technical requirements of digital design of precision plastic injection molding equipment. The reviewes of some key technologies of product configuration, variation and simulation in the digital design are given. The requirements of the development of an integrated design platform are pointed out. Then the architecture and the main content of this dissertation are presented.Chapter 2 studies the fuzzy multi-attribute configuration design of precision plastic injection molding equipment. The fuzzy multi-attribute decision-making method is introduced into the configuration design with fuzzy demands. Taken the uncertainty preferences subjectively into consideration, the non-linear mapping from customer demands to configuration demands is achieved by the knowledge acquisition of fuzzy requirements and the description of fuzzy requirements and product attributes of injection molding machine. Then, the configuration demands are inputted to the fuzzy-level configuration design, while the program collections of configuration design are outputted. The fuzzy-level configuration design is obtained by the similarity identification of non-standard modules and the fuzzy-level solution. Finally, the evaluation model of configuration design with fuzzy multi-attribute decision-making is established with neural network method. The program collections of configuration design are compared and sorted out. Therefore, the optimum results with closest customer satisfaction are obtained.Chapter 3 proposes multi-scale coupling method of product fuzzy configuration and structural variant design in precision plastic injection molding equipment. The concept of multi-scale coupling was introduced into the process of product design. This research studies fuzzy multi-scale configuration, multi-scale variation, and multi-scale coupling methods in heterogeneous systems. Firstly, multi-scale features of transfer-information were analyzed in heterogeneous systems, and the predefined product families were divided into large-scale, middle-scale, small-scale and ultra-small scale according to the state space. Secondly, similar examples were input from fuzzy configuration. These examples construct new structures as outputs through topological changes in structure variant design. Finally, mathematical description of multi-scale coupling process was built in heterogeneous systems. The multi-scale coupling design was achieved throughout multi-scale recursive integration.Chapter 4 puts forward feedback decoupling design of fuzzy configuration of in precision plastic injection molding equipment. In order to resolve the coupling issues of fuzzy configuration design, a new method of feedback decoupling design was proposed. The fuzzy configuration design can be divided into customer domain, functional domain, physical domain, and process domain. Among them, functional domain was mapped to physical domain by the relative gain matrix. The different forms of the relative gain matrix described the different configuration design, including idealized design, decoupling design and coupling design. In view of the coupling design of fuzzy configuration, the process domain was built, including multi-granularity structures for the variation. The process domain was considered as feedback compensation of coupling design, where the relative gain matrix was adjusted by the structural variation, to realize the feedback decoupling design of fuzzy configuration.Chapter 5 studies the multi-variable coupling technology based on the integration of structural variation and simulation analysis in precision plastic injection molding equipment. To achieve the fast response of performance-driven product design, the coupling correlations between structural variation and simulation analysis are established with multiple variables, making the integration of heterogeneous systems feasible. Structural variation is a topological overlap between transplant structures and basic structures. The multiple variables of the process of structural variation can be reserved through the multi-level conversion of structural features. By the principal component analysis, coupling design variables can be extracted. The coupling model with multiple variables can be built and solved to achieve the multi-variable transmission and feedback of heterogeneous systems.Chapter 6 studies the rigid-flexible coupling and solving method of precision plastic injection molding equipment. Currently, the digital prototyping of precision plastic injection molding equipment often adopts multi-body dynamics without considering the elastic deformation of the structres in the movement of mold closing mechanism, so that it is difficult to explain the complex dynamical behavior of precision plastic injection molding equipment. Based on the digital prototyping of twin toggle three links type mold closing mechanism, we deal with the bars, cross hand link, toggle link, and pin rolls flexibility. The rigid-flexible coupling dynamic analysis of twin toggle three links type mold closing mechanism could obtain 22 order modal parameters of bars. The elastic deformation of the cross hand link can be resolved in the starting procedure through the central difference method. The proposed method can provide reference for the development of new products of precision plastic injection molding equipment.Chapter 7 develops an integrated platform among product configuration, structural variation and simulation of precision plastic injection moulding equipment combined with two practical projects. Its implementation in the design of new large dual-platen mold closing mechanism and twin toggle three links mold closing mechanismhave proved the validity and feasibility of the proposed methods in this dissertation.Chapter 8 summarizes this dissertation and prospects the future research.