The Design Of 154 Terminal Connection System And Operating Mechanism

With the development of automotive industry and the increasing complexity of automotive wiring harnesses,automotive connectors have not only appeared as a single part in the structure,but also as a complete system,which play an important role in the transmission of electronic signals and power between various system of automobiles.Its reliability requirements are not only considering the influence of traditional environmental factors such as insertion force,temperature rise and vibration.As a complete system,the operational performance,sealing performance and fastening performance are all important factors to consider.The goal of this project is to design a multi-terminal connection system,and to enable it to meet relevant requirements and standards and make it reliable to use by analyzing and improving various performance of the system.This subject designs the automotive connection system from two aspects,one is the contact terminal as the electrified carrier,and the other is the operating mechanism which responsible for the terminal matching.In the design of the contact terminals,the components and material properties of the terminals are determined firstly.And on this basis,the most critical structure dimension of the plug-spring are calculated by combining with the relevant standards and using the material mechanics formals.In the design of the operating mechanism,the mechanism that can operate stably is designed firstly according to the functional requirements,and the motion process is simulated in MBD for ANSYS software.The length of operating arm is calculated by combining the dynamic simulation and theoretical calculation,to make it enable to meet the design requirement.On the basis of completing design,this subject analyzes connection system fr-om four aspects,the mechanical performance,the sealing performance,the dynamic performance and the electric-thermal performance in accordance with the relevant standards and the working conditions.In the analysis of mechanical performance,the contact force of the terminals and the parts of the operating mechanism is analyzed,and the results show that contact forces of the connection system are satisfactory.Finally,the strength analysis of the structure where the connection system is most likely to be damaged is performed.The results show that connecting system parts will not be damaged during normal use,which ensures the contact performance of the terminal and the fastening between the parts when the connection system is in use.In the analysis of sealing performance,first of all,the Mooney-Rivlin model parameters of silicone rubber are calculated.Then,the deformation,stress and strain of the seal are obtained which combining with the working condition,and the compression ratio of the seal is calculated based on this.Finally,the deformation trend and deformation amount of the seal under 10 MPa water pressure are analyzed.According to the above results,it is concluded that the sealing perfonnance of the seal is satisfactory at room temperature,which ensures the dust-proof performance and water-proof performance of the connection system.In the analysis of dynamic performance,the modal analysis of the connection system is firstly carried out,and the natural frequency is obtained.Then the road surface excitation is calculated according to the actual use environment,and the transient dynamics analysis is caried out based on it which obtain the stress and contact force curves of the contact terminals at the vibration state.The results show that the maximum stress does not exceed the yield limit,and the minimum contact force does not cause the contact resistance to exceed the standard,which ensures the electrification performance of terminal during vibration state.In the analysis of elec.tric-thermal performance,firstly,the contact resistance of the contact terminal is obtained by combining experimental and theoretical calculation.Then the convective heat transfer coefficient of connection system is obtained by analyzing the actual working conditions.And the temperature rise of the connection system in normal operation and short circuit is analyzed based on the above results.The results show that the temperature rise of the connection system is satisfactory,which ensures that the temperature rise of the connection system won't affect the structural components of the system in the energized state.Finally,through the performance analysis of the above four aspects,it is judged that the automotive connection system designed by this subject can be used stably and reliably.