Study On The Influence Of Clutch Torsional Vibration On Vehicle Interior Noise

The clutch assembly is an important component in the powertrain of an automobile,and is the main executive component for power switching.It can effectively cut off and connect the power transmission between the engine and subsequent transmission components.Due to the discontinuity of engine power output,torque fluctuations occur during the transmission of power.The external appearance of torque fluctuations is the speed fluctuation of the transmission system,which is the torsional vibration phenomenon of the transmission system.The self-excited vibration of the clutch assembly during the coupling process and the torque backlash after coupling are important excitations of the transmission system for the vehicle interior vibration.In addition,the torsional vibration damper in the clutch driven disk is an important input to the engine torsional vibration in the transmission system Isolation system.Based on this,in view of the torsional vibration problem of the rear-drive MPV of a domestic four-cylinder engine,the theoretical analysis and experimental research on the influence of clutch torsional vibration characteristics on the interior noise is carried out.First of all,this paper collects and researches the engine cylinder pressure of the vehicle model through bench test,deduces the calculation method and main design parameters of the engine excitation using mechanics and kinematics equations,builds a mathematical calculation model of the engine excitation,and calculates the engine excitation through the mathematical model Load to get the excitation characteristics of the engine of this model under acceleration conditions.Second,build a torsional vibration analysis model of the transmission system.The centralized mass dispersion modeling method is used to split the transmission system into multiple independent components with independent inertia.The inertia of the key components of the transmission system is measured by three-dimensionalsoftware,and the torsional stiffness of the key components of the transmission system is simulated by finite element software.Use LMS.virtual.motion to build a 1D simple transmission system torsional vibration analysis model,input the extracted inertia and torsional vibration stiffness into the model to calculate the torsional vibration mode of the transmission system;use the engine torque load calculated above as the main excitation of the model Input,analyze the forced response of the transmission system,and conduct a sensitivity simulation analysis of the stiffness and damping of the torsional damper in the clutch assembly.Through model simulation,it is found that the clutch has inconsistent effects on torsional vibration attenuation in different frequency bands: for torsional vibration excitation in the amplification and resonance frequency bands,a large damping clutch should be used;for torsional vibration excitation in the vibration isolation zone,the Use a small damping clutch.The frequency division of the amplification zone,resonance zone,and vibration isolation zone is determined by the torsional stiffness of the clutch.Finally,according to the torsional vibration problem of a domestic MPV,the relationship between the clutch stiffness damping and the vibration and noise in the car is obtained according to the previous analysis.The clutch stiffness damping is optimized and modified,and the loading test is verified after the modification.The verification test mainly includes the transmission system.Key point torque,torsional vibration test and vehicle vibration and noise test verification.The verification results show that under a certain torsional vibration excitation,the improved clutch can improve part of the vehicle vibration and noise.