Research On Reducing Diameter Of Thin-wall Copper Pipe And Development Of Automation Equipment

The improvement of computing performance and the development of integration and thinness of electronic products bring problems such as the increase of heat flux inside the chip and the difficulty of product heat dissipation.As a good heat conduction component,heat pipe has a good heat conduction function,and its thermal conductivity is two orders of magnitude higher than that of traditional metal materials,so it has become the first choice of heat dissipation devices for electronic products.With the widespread application of heat pipe in mobile phone electronic products,the thinner the heat pipe is transported,and the thinner the wall thickness of the copper pipe used in the production.Copper pipe shrinkage process is an important part in the manufacturing process of heat pipe,which directly affects the sealing performance of heat pipe,as well as the heat transfer performance and service life of heat pipe.However,the decrease of copper tube wall thickness increases the instability of copper tube shrinkage process,and then increases the difficulty of copper tube shrinkage forming.In order to improve the reducing efficiency and quality of copper tube,this paper makes a comparative study on the rotary forging reducing diameter and the integral mould spinning compression diameter technology commonly used in the production of micro heat pipe.The main research contents of this article are as follows:Based on the theoretical analysis of the forming principle and the correlation law of the process parameters in the process of forming,the kinematics and dynamics model of the process were established to obtain the correlation between the process parameters and the forming force and deformation temperatureABAQUS finite element analysis software was used to establish the corresponding finite element models to simulate the copper pipe forming process under the two diameter reduction processes.The characteristics of the copper pipe wall thickness change,stress and strain distribution,temperature and forming appearance during the forming process were analyzed.And the process parameters that affect the forming quality,such as copper tube wall thickness,feed rate,forming angle and heat treatment state are simulated and compared to obtain the relevant forming rules.Two sets of experimental test platforms were built,and the single factor method was used to conduct comparative experiments on the process of the two kinds of diameter reducing processes,and the effects of different copper tube wall thicknesses,feed speeds,forming angles and heat treatment conditions on the forming quality of the copper tube surface were analyzed.Combining with simulation analysis,the experimental results were demonstrated and further analyzed.The advantages and dis advantages of the two kinds of reducing diameter processes were compared,and the suitable reducing diameter processes and related process parameters under different wall thickness conditions were discussed.When the wall thickness of copper pipe is relatively thick and the sintering state is suitable for the reduction of diameter by rotary forging,the integral mould spinning has a great advantage in the reduction processing of ultra-thin wall copper pipe,especially copper pipe with wall thickness less than 0.2mm.On the basis of theoretical analysis,finite element simulation and experimental verification,three manufacturing processes of copper tube rotary forging shrinkage,tail cutting and tail welding were further integrated into one equipment to complete,and an all-in-one machine for copper tube shrinkage sealing was developed.