Simulation And Experimental Research On Optimal Interference Of Cu6Ni6Sn And QSn7-0.2 Connecting Rod Bushings Based On Workbench

In this paper,the selection of reasonable interference amount in interference connection of connecting rod bushing of an engine is studied.Firstly,the design and calculation of stress and interference amount of thick wall combined cylinder are deduced based on Latin American formula.At the same time,combined with the force analysis of connecting rod mechanism,the theoretical value range of bonding pressure of copper nickel tin bushing and tin bronze bushing is calculated,By combining the theoretical value range of pressure,the corresponding value range of theoretical interference is further obtained.Then,the finite element models of connecting rod liner made of two materials are established by using the finite element analysis software ANSYS Workbench.The contact pressure,equivalent stress of inner and outer walls under assembly condition and maximum compression condition are compared and analyzed,and the optimal value range of interference under different materials is obtained.The research contents and results of this paper are as follows:1.Through the force analysis of the connecting rod mechanism and combining the dynamic formulas of the connecting rod mechanism,the theoretical bonding pressure range of the copper-nickel tin bushing is: 40.74MPa～77.55 MPa,and the theoretical bonding pressure range of the tin bronze bushing Then it is: 40.74 MPa ～ 65.68 MPa.According to the theoretical value range of the combined pressure of the two bushings,the theoretical interference value range of the copper-nickel-tin bushing is: 0.09 mm ～ 0.17 mm,and the theoretical interference value range of the tin-bronze bushing is 0.09 mm～0.14 mm.2.Comparing the simulation and theoretical values of the average contact pressure of Cu6Ni6 Sn bushing and QSn7-0.2 bushing under different interferences,the results show that the maximum error of both does not exceed 6%;and both have an obvious linear relationship.The correctness of the simulation model is verified.Secondly,combining the contact pressures of the two bushings,the distribution law of the equivalent stresses on the inner and outer walls and the numerical changes under the different interferences of the assembly conditions,comprehensively considering the reasonable interference value range of the tin bronze bushing: 0.09 mm ～ 0.12 mm,and the reasonable interference value range of the copper-nickel-tin bushing is 0.09mm～0.15 mm.3.At the same time,the distribution law and numerical change of the equivalent stress of the inner and outer walls of the two bushings under the maximum compression condition are studied,and the reasonable interference value range of the tin bronze bushing under the maximum compression condition should be : 0.09 mm ～ 0.10 mm,and the reasonable interference value range of the copper-nickel-tin bushing should be: 0.09 mm ～ 0.12 mm.Because the copper-nickel-tin bushing can choose a larger amount of interference under the same conditions,the reliability of the interference connection is better than that of the tin-bronze bushing.4.Using two methods of theoretical formula and finite element simulation,the theoretical value and simulation value of the maximum pressing force of the copper-nickel-tin bushing are calculated when the interference of the copper-nickel-tin bushing is respectively taken as 0.09mm～0.12 mm.At the same time,the copper-nickel-tin connection is designed and completed.The rod liner set ligand press-out force test.The error of the maximum pressing force test value of the copper-nickel-tin bushing under the four sets of interference and the theoretical value and the simulation value did not exceed 10%,which verified the correctness of the theoretical value and the simulation value;at the same time,it was found that the increase Increase,the value of the maximum pressing force will increase significantly,and the mating surface will become tighter.The test results show that when the interference is increased from 0.09 mm to 0.12 mm,the maximum pressing force of the bushing increases by nearly 20000 N.It can be seen that the interference has a significant impact on the reliability of the interference assembly.