Research On Servo Pressure System And Technology Of Precision Spot Welding

Insulated copper wire is widely used in electronic industry,especially in aerospace,automobile,intelligent equipment and medical equipment because of its advantages of antierror and anti-short circuit,replacing bare wire material as conductor medium in micro components.Because of the existence of insulation film on the surface of insulated copper wire,the traditional welding process needs to thoroughly remove the insulation film on the joint part,and then realize the welding of copper wire and copper foil.The process is complicated,and it is difficult to achieve the demand of mass production.The precision resistance spot welding technology adopted in this thesis is based on the theoretical basis of hot press welding,which can achieve the whole process of removing the paint film and welding in one step,and is easy to achieve large-scale automatic production.However,due to many factors affecting the welding effect,and the welding process involves a variety of mechanical coupling,there is no mature model for the simulation of welding process.Comprehensive analysis in this thesis,the diameter of 0.2 mm polyester imide enamelled wire with 0.2 mm thick with Sn/Ni plating phosphor bronze copper foil welding process,the precision welding system design and the construction of the welding platform,welding stress in the welding process,precise control of technical parameters such as electrode displacement,in order to realize the good weld strength of welded joint.At the same time,ANSYS software is used for finite element analysis of the welding process from the perspective of thermodynamics and statics to study and analyze the influence of welding parameters（the time used in the welding process,the current provided by the welding power supply,the electrode inclination Angle and the pressure imposed on the electrode during the welding process）on the welding process.Further,the formation mechanism of the welded joint between polyester imide enameled wire and phosphatic copper foil with Sn/Ni coating is explored,which provides a theoretical basis for the finite element analysis of the subsequent welding between polyester imide enameled wire and phosphatic copper foil with different diameters,saving the test time and greatly improving the production efficiency.Finally,orthogonal test and single factor test were carried out between 0.2 mm polyester imide enamelled wire and 0.2 mm thick with Sn/Ni plating phosphor bronze copper foil.The joint quality was studied by means of metallographic analysis.Finally,the influence degree of each process parameter on thermal pressure spot welding of micro-resistance and the optimal combination of welding process parameters are obtained.The experimental data show that the pressure applied to the electrode in the best welding process is 16 N,the current provided by the best welding power supply is 490 A,the welding voltage is 2V,the welding time is 20 ms,and the electrode inclination Angle is 10°.The tolerance between the experimental results and the simulation data is small.