Design Of Function And Structure Of Automatic Pressure Regulator For Vehicle Electronically Controlled Air Braking System

The air braking is the main braking way for heavy-duty vehicles,such as passenger cars and trucks.Its excellent performance is the key to ensuring the safety,stability and smoothness of the vehicles.The pneumatic brake pressure regulating valve is the core pressure regulating device of the air braking system.Its function and performance directly affect the working performance of the entire air braking system.This paper is aimed at intelligent braking,taking air braking circuit and its pneumatic brake pressure regulating valve as the research objects,a new electronically controlled air braking circuit is proposed and an automatic pressure regulator suitable for electronically controlled air braking circuit is designed.The structure of the automatic pressure regulator is systematically studied by the methods of systematic modeling,simulation analysis and experimental verification.The main research work of the paper is as follows:(1)The working principle of the traditional air braking circuit and its shortcomings are analyzed,then a new electronically controlled air braking circuit is introduced.The functions of the automatic pressure regulator which is the core pressure regulating component in the electronically controlled air braking circuit are designed.Aimed at intelligent braking,the performance indices of the automatic pressure regulator are proposed,and the design goal of the automatic pressure regulator is clarified.(2)According to the functional requirements of the automatic pressure regulator of the vehicle electronically controlled air braking circuit,the structural principle and working principle of the automatic pressure regulator is proposed,and the structure of it is designed.The 3D modeling and motion analysis of the automatic pressure regulator are carried out to verify the feasibility of its working principle and determine the biggest opening height of the valve port.The action processes of the key structures and the main influence parameters of the performance of the automatic pressure regulator are analyzed.A hardware-in-the-loop function equivalent test bench is established to test and analyze the functions of the automatic pressure regulator.(3)The analytical model and the Simulink simulation model of the automatic pressure regulator are established.The factor response surface test design method is used to design the simulation test scheme,and the key influence parameters affecting the performance of the automatic pressure regulator are analyzed.The method of fitting simulation test data by multi-factor response surface method is combined with genetic algorithm to optimize the key influence parameters,and the optimal key influence parameters of the automatic pressure regulator structure are obtained.The performance indices of the automatic pressure regulator are tested and analyzed by the automatic pressure regulator simulation model.By using the research results of this paper on the electronically controlled air braking circuit and the automatic pressure regulator,the braking pressure response delay can be shortened,the coordination of braking pressure of each wheel can be improved,the real-time under-pressure compensation of the braking pressure can be realized,and the safety,stability and smoothness of the vehicles can be ensured,which has important engineering application value for the development of electronically controlled air intelligent braking technology.