Research On Influencing Factors Of Electrical Properties Of Reed Electrical Connectors

Automotive electrical connectors are numerous and complex in structure.They are the most essential and basic electronic components in the electrical system.It is of great significance to study the influencing factors of electrical performance reliability of automotive electrical connectors for the design,manufacture,quality control and failure prevention of automotive electrical connectors.The electrical performance reliability of the electrical connector is mainly represented by the contact electrical performance reliability（between the contact pairs of the terminals）and the crimp electrical performance reliability（between the terminals and the copper wire）.In this paper,the automotive reed-type electrical connector is taken as the research object,and the parameters affecting the contact resistance are studied in combination with the electrical contact theory,finite element simulation and experimental research.Combined with experimental research and neural network model,the influence parameters of crimp resistance are analyzed.The specific research methods,research contents and results are as follows:（1）The contact resistance model was derived by combining the electrical contact theory,the terminal normal force model and the Hertz theory.Firstly,the contact failure mode and principle of the contact pair were analyzed.It is clarified that the most significant sign of poor electrical performance reliability of automobiles is excessive contact resistance.Then the terminal positive force model was established.Finally,the contact resistance model was established based on Hertz theory.（2）ABAQUS simulations and experimental measurements were used to verify the normal force model between terminals and the contact resistance model.The results showed that both the model calculated value and the simulated value were within 5%of the error range of the experimental value,and the accuracy was high.（3）Orthogonal experiments were designed.The significance level of the influence of different terminal structure parameters on the contact resistance of the electrical connector with a chip width of 2.3mm was explored.An optimization plan was formulated.Contact resistance was used as the test index and four structural parameters were used as factors,and finally the iso-level orthogonal table of L₁₆（4⁵）was designed.Within 20%of the allowable variation range of each parameter,the structural parameters that have an impact on the contact resistance are ranked as follows:the length of the reed cantilever beam of the female terminal,the thickness of the reed,the interference of the male and female terminals,and the width of the reed.The optimization scheme of each structural parameter was determined,and the optimized contact resistance was reduced by 7.53%.The cantilever length and thickness of the reed have a particularly significant effect on the contact resistance.The influence of the terminal interference and the width of the reeds on the contact resistance of the contacts is not significant.（4）The compression ratio of the cross-section of the terminal and the copper wire after crimping was used as the entry point,and the design parameters affecting the electrical performance of the crimping were deduced in combination with the electrical contact theory.300 sets of crimp resistances with different crimp design parameters were measured.A mapping relationship between crimp design parameters and crimp resistance was established.An optimization scheme for the design parameters was developed.The calculation methods of the crimping cross-sectional area and compression ratio were deduced,and five crimping design parameters affecting the electrical performance of the crimping are obtained,including the crimping width and the crimping height et al.270 sets of data were used as training set and 30 sets of data were used as test set to train the BP neural network model of crimping resistance.The mean square error of the training results was less than 1%,and the coefficient of determination was greater than 0.99,which proved that the accuracy of the mapping relationship of the network prediction model was high.Finally,based on this neural network,the prediction of the electrical performance of crimping was realized,and the optimization scheme of the design parameters of the terminal crimping was formulated.The research method used in this study can provide ideas for the structural design of the automotive electrical connector and the optimization of the crimp design parameters.The obtained conclusions guide the structural design of the contact pair of the automotive electrical connector and the design,manufacture and quality control of the crimping design parameters.