Research On Pressure Characteristics And Optimization Design Of Pneumatic Parking Brake System Of A Commercial Vehicles

With the development of road construction and automobile technology,the carrying capacity and speed of commercial vehicles continue to improve,which gradually pose higher requirements for the performance of commercial vehicles.Pneumatic parking brake system is a key safety device of commercial vehicles,whose braking pressure characteristics directly determine the system performance and then affect the safety and reliability of vehicles.In order to tackle the engineering problems such as slow release of parking brake and poor parking brake performance caused by poor pressure characteristics,the method of theoretical analysis,simulation experiment and test verification are adopted to accurately explore the pressure characteristics and key influencing factors of pneumatic parking brake system,which is of great significance to improve the braking performance of the system.The main research work of this paper is as follows:(1)By consulting relevant literature,the research status of pressure characteristics of commercial vehicle pneumatic brake systems and key components at home and abroad were understood,and the structure and working principle of the pneumatic parking brake system,the basic theory of pneumatic system modeling,etc.were introduced.The structure and working principle of each key component were analyzed in-depth,and the mathematical model for the pressure characteristics of key components such as parking brake valve,relay valve,spring brake chamber were established.(2)Based on the pneumatic foundation theory and the mathematical model of components,simulation models for the pressure characteristics of key components and systems such as parking brake valve were established using MATLAB/Simulink software to obtain the simulation data of pressure characteristics of various key components and systems.(3)An experimental platform for the pressure characteristics of the commercial vehicle pneumatic parking brake system was set up,and key components and systems were tested according to relevant standards,and the simulation and test data were compared to verify the accuracy of the pressure characteristic simulation model.The comparison results show that the overall trend of the two sets of data is relatively consistent,and the error is relatively small,which proves that the test scheme is reasonable,and the simulation model is accurate and meets the experimental requirements.(4)Using the verified simulation model for pressure characteristics of the pneumatic parking brake system,the key influencing factors of the pressure characteristics of the system were analyzed,and the orthogonal test method was used to obtain the optimization scheme of the system: 10 mm diameter one-way valve,1m installation position of the relay valve,and 750 m L initial volume of the air chamber.Finally,the results before and after optimization were compared and analyzed: the inflation response time and deflation response time of the system were reduced by 0.16 s and 0.24 s respectively after optimization,and the problem of slow release during parking brake was improved,and the parking brake performance was significantly improved.The research content of this paper can provide reference for simulation modeling of pressure characteristics of pneumatic parking brake system of commercial vehicles and serve as a theoretical basis for structural optimization of components and system design and matching,which improves parking brake performance of commercial vehicles and shortens development cycle and reduce costs.Therefore,the research content of this paper plays a certain guiding role in both theoretical research and engineering problems.