Concept Design And Performance Optimization Research Of Special Fixture In Precision Gem Machining Equipment

Fixture system is the critical system to achieve machining processing. The constitution and precision of fixture system have a direct impact on processing efficiency and product quality. This paper makes "Gem Machining Center" as the research background, and fixture system as the research object; Focuses on concept components and the improvement of fixture system, and finally realizes the structures of fixture system.In the first chapter, basic concept and basic step of fixture are summarized, and application situation of fixture optimization is introduced; Research status of fixture positioning optimization and system dynamic optimization in domestic and overseas is mainly analyzed. Finally, the author points out the paper's research content and structure.In the second chapter, fixture constitution in real manufacturing is analyzed; Based on the product and processing, positioning, transmission, main structure and whole framework are designed. And the basis of following chapters is provided.In the third chapter, fixture positioning performance optimization model based on concept design is researched, and combined with Genetic Algorithms(GA), performance of fixture positioning is optimized. There are two factors that can affect the positioning accuracy, one is dimension and its deviation of positioning device, the other is manufacture error of previous procedure and dimension of workpiece positioning benchmark. If the manufacture precision is fixed, positioning error of workpiece is mainly decided by the distribution of anchor points in the surface of workpiece. Static positioning performance optimization based on GA achieves a higher fixture positioning accuracy.In the fourth chapter, fixture system dynamics model based on concept design is researched. Combined with Modal Analysis, Anti-vibration performance of fixture system is optimized. Fixture system is a flexible system which has a continuous distribution mass, so it's a system that has multi-degree of freedom. Through several-mode analysis of fixture system dynamics model, dangerous mode of fixture system is found. And improvement of the original fixture system is achieved according to the result of mode-analysis. Dynamic anti-vibration performance optimization based on mode-analysis realizes the improvement of processing precision in fixture system.In the fifth chapter, structure design of fixture system is completed. The final target of fixture system design and optimization is realizing producing in factory, so mechanical drawings for machining is a key step of fixture system. The realization of fixture system structure views the factory machining as basis to instruct factory production.In the last chapter, summarizes the contents and the achievements of this paper, and points out the further research direction.