The Analysis And Improvement On A Commercial Vehicle M100 NVH Performance

With the increase of people's consciousness to protect environment, the more strict roles of the government and the higher requirement of a comfortable automobile,the NVH performance of vehicle will become one of the most important traits at the automobile market in the future. The research of vehicle NVH test would play an important role.To improve the NVH of the M100 car which is in the developing, some works have been engaged, some tests on the car have been done systematically, and marked with target type at the same time. Through making analysis and optimization to the existing problems, then testing verification, to make the noise of the new design cars reaches the goals finally.The main research work are as follows:(1) The characteristics of the vehicle NVH is introduced, and the present situation and the development tendency on the vehicle NVH test at home and abroad are illuminated. Vehicle NVH testing technology theories including vehicle vibration noise test general process, test instrument, test environment, vibration noise source identification technology and the transfer path analysis technology are mentioned.Under various operating conditions, vehicle produces vibration and noise, according to the transfer path analysis, to confirm the vibration noise and put forward the basic measures of vibration and noise reduction.(2) To a commercial vehicles M100, it made NVH road test, enacted the experiment purpose, experimental design, experimental method etc.; Test contents have vibration and noise under idle condition, vibration and noise under three full throttle acceleration and high speed condition etc., and have carried on the comparative analysis of the reference vehicle, meanwhile test scheme including M100 the co-pilot seat high-speed jitter and rearview mirror abnormal sound phenomenon is put forward.(3) According to the results of M100 vibration noise analysis, based on the principle of vibration noise control, improvement and validation containing the dash panel sealing, air-conditioning piping vibration isolation, fan dynamic balance, the co-pilot seat and rearview mirror was conducted.The experimental study of a commercial vehicle M100 NVH characteristics, theresults have been applied to M100 to achieve good effects. Through the study of this paper, there are some certain guidance and reference functions to the NVH performance improvement of the vehicle development and the quality improvement.