Research On Optimization Of Automobile Horn Structrual Parameters Based On Fatigue Life Analysis Of Diaphragm

In order to attract the attention of the pedestrian and the vehicle,each car is equipped with electric horn to ensure our safety.Its performance is good or bad will directly affect the traffic safety,so the role of the horn cannot be ignored.Compared with foreign country,domestic use-rate of the horn is very high.But,domestic car horn manufacturers consider the cost and other factors so that they don't increase the horn of life and properties to the appropriate level.In this paper,we take a car horn diaphragm as the research object,to study its fatigue life,so as to provide reference for the structural parameters of the diaphragm design.Mainly carried out the following research work:This article fisrtly from the fatigue crack initiation and propagation and fracture explains the mechanism of the fatigue,and explains the influence of stress concentration,loading forms,and surface conditions on fatigue life.Then the paper describes the fatigue damage accumulation theory,and a method to estimate the fatigue life of material is derived by the linear cumulative damage theory.Then it describes the basic structure and the working principle of the mechanical contacting type automobile horn.Under the electromagnetic force,the horn diaphragm vibrate continuously and radiates sound.Therefore,the rupture of diaphragm horn become the main form of horn failure.Using SolidWorks and HyperMesh establish the finite element model of horn diaphragm.Through giving it mesh,constraints and solving,we get the low-order main vibration shape of the diaphragm.Comparing the analysis of the main vibration shape,it is concluded that only the first-order modal diaphragm is piston motion.And then import the three-dimensional model into ANSYS to analyze harmonic response.Simplifying electromagnetic force to get the curve of frequency-displacement and frequency-stress.analyze the main vibration direction and the maximum stress node.Through the experiment,we acquit the displacement of moving iron core information over time.According to the basic theory of the coupled multi-body dynamics,use Adams to simulate horn diaphragm and moving iron core.The horn diaphragm center load spectrum is got.Using Fatigue analyze the horn diaphragm and estimate its fatigue life.It is concluded that the least service life of the diaphragm take place in the line belt near the moving iron core,and life expectancy is of 8.51×10~4 times.Finally,Based on the horn diaphragm fatigue life analysis,with the finite difference method we solve the sensitivity of various factors,and get the horn diaphragm thickness is most sensitive to the fatigue life.Establish the orthogonal experiment,through calculation and analysis to determine the optimal scheme,the best solution is: t=0.4mm,radius3=24.50 mm,radius4=36.50 mm.Through the optimization of structural parameters of diaphragm,the life of the horn diaphragm is increased to 1.03×10~5 times.