【作者】 伍权；

【导师】 张祥林；

【作者基本信息】 华中科技大学 ， 材料加工工程， 2007， 硕士

【摘要】 冷挤压技术是一种高精、高效、优质低耗的先进生产工艺技术,已成为当今塑性加工领域重点研究和发展的方向之一。本文研究的Z型衔铁零件是某电磁继电器的关键部件,属于异形非对称件,其几何形状复杂,精度要求高,加工难度大,采用传统加工工艺方法进行生产,难以满足企业日益增长的需求,已经成为制约企业发展的瓶颈。文章针对衔铁零件的工艺特点,创造性的提出了冷挤压加工方法制造衔铁零件的方案。文章采用理论分析、有限元数值模拟和实验研究相结合的方法,对Z型衔铁冷挤压成形工艺、模具设计及其关键技术进行了研究。在对衔铁零件进行工艺分析的基础上,对衔铁零件挤压模具进行了结构设计。文章从衔铁零件冷挤压成形的关键部件-凹模型腔入手,采用正交设计方法,结合有限元分析软件DEFORM-3D,对影响挤压力的凹模型腔结构参数进行优化设计,得到最优化的凹模结构参数。在此基础上,文章对优化后的结构进行模拟,得到变形过程的行程―载荷曲线、应力、应变场等信息,并分析模具的应力情况,将凹模结构改为纵向剖分式以改善应力集中现象。为验证凹模优化设计结果,本文在挤压机上进行了多次挤压工艺试验,得到了有价值的实验结果。试验结果表明,Z型衔铁正向冷挤压工艺方案和模具结构基本可行,同时验证了型腔优化结果对降低挤压力的有效性。更多还原

【Abstract】 The goal of the investigation is to theoretically and experimentally demonstrate the key points of using extrusion-die to manufacture armature part, which is a kind of asymmetry iron‘Z’shape work piece that is often used in relay assembly. The work piece is a complex one with high degree of accuracy. The common way to manufacture it contains several machining procedures resulting high costs and low efficiency which becomes the bottleneck of the company to meet the need of market. To overcome these difficulties, this paper creatively adopts cold extrusion method to make it.Basic plastic deforming theory and FEM software and experiments are used to study the cold forming of the part in this paper. Over the analysis of the processing property, a structure of the extrusion die is designed for the research. In order to gain the lowest load, the orthogonal design combined with DEFORM-3D is adopted to optimize parameters of the cavity which is the key part of the extrusion die. The inner stress field, strain field, metal flowing law and forging travel-load curve during the forming procedure of the optimized structure are figured out after the simulation, and structure of the die is changed as longitudinal divided cavity to avoid stress concentration.Extrusion experiments were done to verify the optimization, and several satisfied net-shape work pieces with smooth surface were gained. The accomplishment of the experiments demonstrates that extrusion die can be successfully used to manufacture asymmetry parts, and the optimization is effective to reduce the extrusion force. This innovative research also has practical reference values for die design.更多还原