The Research On Steering Characteristic Of Steering Mechanism

The steering system is a special mechanism which is used to change or recover thedirection of car driving, and its steering characteristic which is one of the kernel of thevehicle technologies plays an critical role in handling stability and security of car driving.The property of the vehicle steering system and steering characteristic is decided by thedesign of steering mechanism. The driving comfort, life of tire is affected by the design ofsteering mechanism.The content of this article’s research is the basic research part of the project, which isaided by the project of Chongqing science research plan (the project number isCSTC.2009AB6021)’the research and industrialization of the key technology of electricpower steering system’, and discussing the steering mechanism which is the basic part ofthe steering system. The theory of the steering triangle is advanced and the optimizationdesign of the existed plane steering mechanism is perfected by the research of the planesteering trapezoid mechanism. And the space suspension-steering mechanism model is setup which in order to research the influence of the steering mechanism’ steeringcharacteristic by the moving up and down of the suspension, and then get the conclusion.The main research contents include:1、The development and the works of the existed vehicle steering system is introduced.The research present situation and the development trend of the steering mechanism bothat home and abroad are analyzed. The existing theories for the influence of the steeringcharacteristic of the plane steering mechanism are analyzed and the limitations of theexisting optimization theories are studied. The steering principle, mechanical structure,working principle and key technology of the existing steering mechanism are analyzed.And the advantages and disadvantages of the front wheel steering mechanism areproposed.2、The mathematical model of the plane steering trapezoidal mechanism is set up bythe research of steering mechanism’s working principle. The steering triangle theory is putforward, and the intersection of the trapezoid arm’s extension cord (the vertex of thesteering triangle) as the research object, the influence of characteristic curve(thecharacteristic curve of the steering), which changed by the change of the steering triangle’svertex, are respectively discussed by the change of trapezoid arm and corner. 3、The basic concepts of the multiple body system theory and the ideal transformationmatrix and practical movement matrix between the adjacent bodies in the multiple bodysystem are introduced. The theoretical basis of the design of the space mechanism is stated.4、The independent suspension is introduced and the current research status of theMcpherson suspension and steering mechanism of domestic and international scholars isanalyzed. Based on this, the influence of the steering mechanism’ steering characteristic bythe research of the moving up and down of the suspension or vehicle load quantity is putforward according to the theory of multiple body system.5、The mathematical model of the space Mcpherson independent suspension andpinion and rack steering mechanism is set up according to the theory of existing multiplebody system based on a car’s Mcpherson independent suspension and pinion and racksteering mechanism as the research object. The key parametric points and sizes of thespace mechanism are designed. Base on the suspension and steering mechanism’s size ofJetta car and the mechanism model is set up by the software of Matlab, the results is got bythe program operation according to the influence of the steering mechanism’ steeringcharacteristic with the suspension’s moving up and down or the vehicle load quantity.