Experimental Investigation On Noise Characteristics Of Engine Timing Silent Chain System

As a new form of transmission in engine valve timing system, timing silent chain drive are increasingly used in the modern gasoline engine with its low noise, strong wear resistance, high transmission efficiency and reliability. However, there is a large gap in technological level between domestic chain industry and industrialized countries as well as key development technology of timing silent chain is monopolied by foreign countries. These factors are constraining the development of key technologies about domestic research and performance evaluation for timing silent chain system which could meet the low engine noise and high reliability requirements. This paper was supported by major science and technology projects of Jilin Province "Research on the key technologies in development of modern gasoline engine timing chain system" which was cooperated with FAW technology center. For self-developed TA1gasoline engine timing silent chain system, through bench test and engine ignition test, the noise characteristics of self-developed timing silent chain system and original system at different speeds and different experimental conditions were analyzed and researched with the aim of establishing domestic noise test specifications and analytical skills for timing silent chain drive system.In this paper, the layout and working characteristics of different types of timing system were presented. The advantages and disadvantages of several engine timing systems and the different characteristics of silent timing chain and roller chain system were compared. The layout and working principle of self-developed TA1gasoline engine timing chain system was described in detail. In addition, the main source of the timing chain’s working noise was introduced briefly in this paper which laid the theoretical foundation for the study of the noise characteristics of the timing chain. In this paper, under the same measurement conditions, noise tests of self-developed timing chain system and original timing chain system were conducted in different speeds in self-developed noise test rig for TA1gasoline engine timing chain system, and the noise data was compared. Through bench test, the noise characteristics were analyzed when there was no engine load.On the basis of the first self-developed noise test rig for timing chain system, a new test rig was developed with some improvements in this paper in order to solve the problem that high-speed conditions noise test cannot be achieved in the first self-developed test rig. The noise of self-developed timing chain system and original timing chain system were tested on the new developed test rig and the data was compared with obtained obviously. The noise characteristics of timing chain system were researched, and the test performance of improved test rig was verified.In order to research the noise characteristics of self-developed timing chain system under actual ignition condition, ignition noise contrast tests of self-developed timing chain system and original timing chain system were taken in powertrain anechoic chamber. Through the engine ignition experiment, noise characteristics were studied during the process of the engine ignition and when the load was100%. The noise test compared data were analyzed to verify the noise performance of the self-designed timing silent chain system.The research results in this paper provide an important theoretical support for the study about timing chain noise and vibration. It has far-reaching for the establishment of R&D capabilities, enhancing the competitiveness of domestic engine timing silent chain system, as well as creating a competitive domestic brands.Results of this study have significance engineering guiding value in noise measurement and characteristics research of timing silent chain systems, and will effectively promote the formation of noise test specifications and performance evaluation techniques capacity of domestic independent timing silent chain system.