Research On Structure Optimization And Tightening Technology Of Connecting Rod Bolts For Passenger Cars

The connecting rod bolt is one of the important components of the engine connecting rod set.Its main function is to connect the connecting rod end cover,the connecting rod bearing bush and the connecting rod rod body,and bear all the loads transmitted by the piston to the connecting rod.In practical engineering applications,the bolts and bolts are subjected to complicated forces and the working environment is harsh.Therefore,problems such as failure of the structure due to unreasonable structural design or failure of the connection of the connecting rod due to unreasonable tightening of the assembly method often occur during use.Failure of the connecting rod bolts can lead to failure of the connecting rod group,which can lead to engine failure or even scrapping,and may even threaten the safety of the vehicle personnel.Therefore,research on the structural design and tightening process of engine connecting rod bolts is essential for the stability and reliability of engine use.In this paper,the connecting rod bolt of passenger car engine is taken as the research object.Through the dynamic analysis of the crank-and-rod mechanism of the engine,the actual working force of the connecting rod bolt is obtained,and the curve of the force of the connecting rod bolt is drawn.According to the finite element analysis method,the ANSYS Workbench analysis software transient dynamics analysis module is used to analyze the structural strength of the connecting rod bolt under the extreme engine conditions.According to the optimization design principle,for the dangerous parts of the connecting rod bolt under the extreme working conditions of the engine,the structural parameter optimization design method is selected to optimize the structural design of the connecting rod bolt,and the structural strength performance of the connecting rod bolt is improved.The manufacturing process is the key link from design to use of the connecting rod bolt.This paper analyzes and designs the key manufacturing links of the connecting rod bolt after structural optimization,and carries out trial production.According to the national performance standard of high-strength bolts,the relevant performance test of the trial-made connecting rod bolts is obtained,and the core parameter values of the connecting rod bolts are obtained.Through the test results,the new design of connecting rod bolts has reached the standard and design parameters,which meets the actual use requirements and improves the structural performance.The connection quality of the bolt directly affects the performance of the connecting member.In this paper,the structural optimization of the connecting rod bolt is taken as an example.The connection reliability and stability are the entry points,and the tightening method of the bolt is analyzed and studied.Combined with the actual assembly tightening conditions of the connecting rod bolts,the most effective tightening method that can be achieved is determined by the test comparison analysis.Through friction performance test,finite element simulation analysis,provide basic parameters for the tightening process design,and calculate and tighten the process test according to the theoretical formula,and design parameters for the torque/rotation tightening process of the connecting rod bolt.Through the research,the application of the torque/turn angle method in the assembly and tightening process of the engine connecting rod bolts is realized,and the design direction is provided for the tightening of the connecting rod bolts in the future.