The friction judder characteristics during clutch engagement have a significant influence on the NVH of a driveline.In this research,the judder characteristics of automobile clutch friction materials and experimental ...The friction judder characteristics during clutch engagement have a significant influence on the NVH of a driveline.In this research,the judder characteristics of automobile clutch friction materials and experimental verification are studied.First,considering the stick-slip phenomenon in the clutch engagement process,a detailed 9-degrees-of-freedom(DOF)model including the body,each cylinder of the engine,clutch and friction lining,torsional damper,transmission and other driveline parts is established,and the calculation formula of friction torque in the clutch engagement process is determined.Second,the influence of the friction gradient characteristics on the amplification or attenuation of the automobile friction judder is analyzed,and the corresponding stability analysis and the numerical simulation of different friction gradient values are carried out with MATLAB/Simulink software.Finally,judder bench test equipment and a corresponding damping test program are developed,and the relationship between the friction coefficient gradient characteristics and the system damping is analyzed.After a large number of tests,the evaluation basis of the test is determined.The research results show that the friction lining with negative gradient characteristics of the friction coefficient will have a judder signal.When the friction gradient value is less than-0.005 s/m,the judder signal of the measured clutch cannot be completely attenuated,and the judder phenomenon occurs.When the friction gradient is greater than-0.005 s/m,the judder signal can be significantly suppressed and the system connection tends to be stable.展开更多
The clutch is an important component of the vehicle driveline system.One of its major functions is to attenuate or eliminate the torsional vibration and noise of the driveline system caused by the engine.Based on expe...The clutch is an important component of the vehicle driveline system.One of its major functions is to attenuate or eliminate the torsional vibration and noise of the driveline system caused by the engine.Based on experiments of vibration damping under different vehicle conditions,the structure and functional principle of a clutch-driven disc assembly for a wide-angle,large-hysteresis,multistage damper is investigated in this study using an innovative combined approach.Furthermore,a systematic integration of key technologies,including wide-angle low-stiffness damping technology,large-hysteresis clutch technology,a novel split pre-damping structure technology,damping structure technology for component cushioning,and multistage damping structure technology,is proposed.The results show that the total torsional angle of the wide-angle large-hysteresis,multistage damper is more than twice that of the traditional clutch damper.The multistage damping design allows a better consideration of various damping requirements under different vehicle conditions,which can effectively address problems of severe idle vibrations and torsional resonance that occur under idled and accelerated conditions.Meanwhile,the use of a large-hysteresis structure and wear-resistant materials not only improves the vibration damping performance,but also prolongs the product service life,consequently resulting in multi-faceted optimization and innovative products.展开更多
基金Supported by National Natural Science Foundation of China (Grant No.51775249)。
文摘The friction judder characteristics during clutch engagement have a significant influence on the NVH of a driveline.In this research,the judder characteristics of automobile clutch friction materials and experimental verification are studied.First,considering the stick-slip phenomenon in the clutch engagement process,a detailed 9-degrees-of-freedom(DOF)model including the body,each cylinder of the engine,clutch and friction lining,torsional damper,transmission and other driveline parts is established,and the calculation formula of friction torque in the clutch engagement process is determined.Second,the influence of the friction gradient characteristics on the amplification or attenuation of the automobile friction judder is analyzed,and the corresponding stability analysis and the numerical simulation of different friction gradient values are carried out with MATLAB/Simulink software.Finally,judder bench test equipment and a corresponding damping test program are developed,and the relationship between the friction coefficient gradient characteristics and the system damping is analyzed.After a large number of tests,the evaluation basis of the test is determined.The research results show that the friction lining with negative gradient characteristics of the friction coefficient will have a judder signal.When the friction gradient value is less than-0.005 s/m,the judder signal of the measured clutch cannot be completely attenuated,and the judder phenomenon occurs.When the friction gradient is greater than-0.005 s/m,the judder signal can be significantly suppressed and the system connection tends to be stable.
基金Supported by National Natural Science Foundation of China(Grant No.51775249).
文摘The clutch is an important component of the vehicle driveline system.One of its major functions is to attenuate or eliminate the torsional vibration and noise of the driveline system caused by the engine.Based on experiments of vibration damping under different vehicle conditions,the structure and functional principle of a clutch-driven disc assembly for a wide-angle,large-hysteresis,multistage damper is investigated in this study using an innovative combined approach.Furthermore,a systematic integration of key technologies,including wide-angle low-stiffness damping technology,large-hysteresis clutch technology,a novel split pre-damping structure technology,damping structure technology for component cushioning,and multistage damping structure technology,is proposed.The results show that the total torsional angle of the wide-angle large-hysteresis,multistage damper is more than twice that of the traditional clutch damper.The multistage damping design allows a better consideration of various damping requirements under different vehicle conditions,which can effectively address problems of severe idle vibrations and torsional resonance that occur under idled and accelerated conditions.Meanwhile,the use of a large-hysteresis structure and wear-resistant materials not only improves the vibration damping performance,but also prolongs the product service life,consequently resulting in multi-faceted optimization and innovative products.
