Simulation Analysis And Optimization Of Roll Characteristics Of Air Suspension For Heavy Duty Vehicle

V rod air suspension is a kind of double trailing arm type air suspension and it is universally applied on heavy duty trucks.Compared with leaf spring suspension,it has the advantages of light weight,good ride comfort and long service life.However,since the rigidity of air suspension is relatively small,and no roll angle stiffness is raised by the V rod guiding mechanism,the roll angle stiffness of suspension is very small,which makes the stabilizer bar must be installed.Considering the problem of big vehicle body roll angle occurred during the test of a heavy duty vehicle equipped with V rod air suspension,this paper using simulation technology analyzes the influences of V rod and X rod on air suspension roll characteristics and vehicle stability,improve the V rod to X rod and optimize the vehicle handling stability.The main contents are as followings:1)States the roll characteristics of air suspension,deduces the calculation formulas of vehicle roll angle stiffness and body roll angle and sketches the influence of suspension roll on vehicle handling stability.2)Introduces the heavy duty vehicle modeling method and instructions in software Adams/Car and establishes the kinetic models of vehicle and frame and subsystems of front leaf spring suspension,rear air suspension,cabin,power transmission system and tires.There are two kinds of air suspension models and guiding mechanisms are V rod and X rod respectively.3)Simulation analyzes the roll characteristics of V rod and X rod air suspension.The roll angle stiffness of X rod guiding mechanism is bigger than V rod guiding mechanism.In the case of the suspension structure is basicallydetermined;the rubber bushing of X rod-drive axle has the greatest influences on X rod air suspension roll angle.4)Steady state cornering and angle step input of steering wheel simulation test of the two kinds of kinetic models equipped with V rod and X rod air suspensions.The bigger the roll angle stiffness,the smaller the body roll angle.The bigger the degree of understeer,the smaller the exceed value of yaw rate.Finally,it optimizes the X rod air suspension to achieve the improvement of the vehicle handling stability,...