Research On Quality Control Method Of Multi-pass Deep Drawing Of Micromotor Shell

The micromotor shell,as the matrix parts of the micromotor,plays the role of bearing,assembly and protection,etc.,the use environment is becoming more and more complex,the quality requirements for wall thickness uniformity and surface finish are getting higher and higher.And the high diameter ratio of the micromotor shell is large and the thickness of the plate is thin,it needs to go through many times deep drawing forming,the workpiece is prone to thinning and cracking in the process of forming,it presents a new challenge to the fabrication of the micromotor shell.The manufacturing of micromotor shell belongs to the traditional stamping industry,which is in the current situation of large output and low profit.It is also a dilemma for enterprises to reduce the production cost while improving the product quality.In this paper,the micromotor shell was taken as the research object,and the key technology of multi-pass deep drawing of micromotor shell is studied by means of theoretical research,simulation analysis and experimental research,and two forming processes of flexible edge lap and thinning deep drawing to improve product quality are developed.The main research work of this paper is as follows:(1)Study on the formability of micromotor shell material.The basic mechanical properties of two kinds of micromotor shell materials SECD and DX53 D were obtained by uniaxial tensile tests.The drawing property,hardening property and anisotropy were analyzed.The material constitutive parameters were modified by the combining the material model of finite element platform and experimental data.The results show that two kinds of galvanized steel plates are suitable for deep drawing of micromotor shell.(2)Research on technology and forming quality of micromotor shell progressive deep drawing and edge lapping.A flexible edge lap structure for progressive forming was proposed.Based on the finite element analysis,the method was compared with the traditional scrap-cutting type and slit-cutting type for the uniformity of wall thickness.The results show that not only the forming quality is improved,but also the material utilization rate is improved.(3)Research on mirror deep drawing technology and forming quality of micromotor shell.In this paper,a mirror drawing process was proposed,which can overcome the problems of excessive thinning of wall thickness by controlling the stamping parameters such as stamping speed,friction condition and die clearance while ensuring the surface smoothness.The influence of the process parameters on the forming quality was studied by using the finite element technique.The results show that the mirror deep drawing technology can control the forming quality effectively.(4)Experimental study on forming process and quality of micromotor shell.For the two kinds of micromotor shell products,the process schemes of flexible edge lap progressive forming and thinning deep drawing were developed,and the test dies were designed and manufactured,and the test results were compared with the simulation results.The results show that the forming quality of the trial-manufactured micromotor shell is good,and the experimental results are consistent with the simulation results basically.The research results in this paper have certain accuracy and reliability.