Simulation And Experimental Study On Operating Performance Of A Variable Piston Shock Absorber For Vehicles

Traditional shock absorber for rigid piston friction and heat phenomenon has not been able to get a good treatment,this paper designed a flexible piston to drive the vehicle variable piston shock absorber,and analyzed the working principle of the shock absorber,the internal obstruction link generated by the damping force analysis,each kind of working stroke are built a corresponding mathematical model and simulation to obtain the theoretical external characteristic curve,and finally the made shock absorber placed on the test bench for testing and analysis of test results,specifically from the following aspects:According to the current situation of shock absorbers at home and abroad,the relevant research content of the shock absorbers is analyzed,which provides a relevant reference for the design of automotive variable piston shock absorbers in this paper.The shock absorber in the slow and fast state of motion in the oil flow direction to make a specific description,different strokes of the oil flow through the structure and quantity are different,in this process need to use two-dimensional and three-dimensional diagrams to assist in the oil through the obstruction structure,the overall structure of the shock absorber has a deep understanding,in each part of the deliberate flexible piston and piston linkage of the two"center" design focus.In the damping characteristics of the shock absorber,a detailed analysis of the internal characteristics is carried out,focusing on the throttling theory of gap flow,thin-walled orifice flow,nozzle flow,slender orifice flow inside the shock absorber,and analyzing the structure of these damping elements and the relationship between pressure difference and flow rate.Based on the relationship between the oil flow direction,flow rate and pressure difference within the shock absorber,the mathematical model of the damping force of the compressive stroke(fast/slow)and the recovery stroke(fast/slow)of the shock absorber is established,and the mathematical modeling of the shock absorber is calculated with the help of MATLAB/Simulink,and the theoretical external characteristic curve of the model is obtained and the rationality of the established mathematical model is analyzed.According to the relevant regulations in the "QC/TC491-2018 Automotive Shock Absorber Performance Requirements and Bench Test Methods" formulated in China,a test scheme was formulated for the automotive variable piston shock absorber studied in this paper,and compression and restoration experiments were carried out on the test bench to obtain the actual external characteristic curve of the shock absorber,analyze the cause of the error between the external characteristic curve and the theoretical external characteristic curve,and prove the accuracy of the mathematical model of the shock absorber.