Design And Optimization Of The Automatic Tensioner Of The Engine Front End Accessory Drive System On Vehicle

This article is mainly pay more attention to studying the automatic tensioner of theEngine Front End Accessory Drive (referred to as EFEAD) system on Vehicle, includingtheory exploration and experimental verification. Because our technical level of automatictensioner’s design, development, production and other fields is still in the early stage. So itneeds to carry out more perfect and deeper research about design theory and method ofautomatic tensioner. In this paper, main works have been done in the following content:1. Makes detailed introduction about structure composition, working principle,performance index and experimental verification of automatic tensioner. Expounds themeanings and purposes of the identification position on automatic tensioner. Points out thatkeys technology of automatic tensioner design are the helical torsion spring and dampingmechanism.2. The design process of automatic tensioner is discussed, which includes the designand calculation of EFEAD system and the design method of some parts. Especially this papergives deep research about the design and calculation of the helical torsion spring and dampingmechanism, establishes the mechanism model, and then deduces the calculation formula oftorque value and damping value.3. In the design process of automatic tensioner, faces two shortages which are that thetraditional design method of helical torsion spring is very backward and poor precision, andthe asymmetric damping value of the existing damping mechanism is not ideal. And then thispaper has carried out the optimized design. Compiles the optimized calculation proceduresbased on the GUIDE function and fmincon() function of MATLAB software, which caneffectively solve weakness of traditional design method. Builds the new damping mechanismmodel after deeply studying the asymmetric damping coefficient, and then makes deductionof calculation method of damping coefficient.4. Does experimental exploration of automatic tensioner before and after optimization.This paper introduces the experimental equipments and methods. And then gets experimentalresults of various performance parameters, such as the belt’s static tension, the rotational vibration amplitude of the tensioner arm, the belts’ transverse vibration amplitude and so on.At last, compares the results before and after optimization in order to verify that optimizedresults.5. Finally, reviews and summarizes main works about the thesis that is studied,afterwards makes prospect about the future research direction and contents.