Study On Analyzing Method Of Electrical Contact Performance For Spring Touch Finger Structure

The spring touch finger structure is now widely used in high-power electrical interconnection industrial cases.In this paper,the spring touch finger structure is taken as the research object,and the influencing factors of the electrical contact performance for spring touch finger structure are studied by theoretical calculation,finite element(FE)simulation and experiments.The analyzing method of electrical contact performance for spring touch finger structure under three working conditions: static contact,mechanical insertion and retention and continuous electrification is studied.Firstly,according to the structural features of spring touch finger,a single turn of spring is equivalent to a cantilever beam,and a theoretical analysis method of contact pressure and insertion and retention force is proposed.The contact between spring and pin is equivalent to Hertz contact,and the associated theoretical analysis method for calculating contact area and contact resistance is established.Further,the temperature rise model is established,and the influences of spring structure parameters and current on contact temperature are analyzed.Secondly,the FE simulation analysis method for mechanical field of spring touch finger structure is presented,and the relationships between contact force and insertion and retention force are analyzed.The influences of pin displacement,diameter of spring wire,number of turns and diameter of spring on contact force and insertion force are analyzed by the single control variable method.Based on the periodic characteristics of the spring,a simplified method for calculating the contact force and contact area of the spring touch finger structure is proposed,which can substantially improve the computational efficiency.Furthermore,a FE simulation analysis method for thermoelectric coupled field of spring touch finger structure is presented,and the relationships among contact area,contact resistance and contact temperature rise are determined.The influences of number of turns,diameter of spring wire,diameter of spring and current on contact area,contact resistance and contact temperature rise are analyzed by the single control variable method.At the same time,a simplified model for simulating the contact resistance of the spring touch finger structure is proposed,which can improve the efficiency of modeling and computing.Finally,a test rig for the insertion and retention characteristics of spring touch finger structure is designed,and the variations of the insertion and retention force and contact resistance as a function of time are obtained.Based on image processing technology,an extraction and analysis method for analyzing the contact surface outline features is proposed,and the restriction resistance value can be re-estimated with the obtained contact area.The method mentioned in this paper can be directly applied to the design of spring touch finger structure of high-power electrical connectors and to the analysis of electrical contact performance for spring touch finger material.