Research On Pressure Characteristics Of Bus Air Brake Chamber

Pneumatic brake system is widely used in bus braking.Bus air brake chamber is an important part of bus air brake system,the role of brake chamber in bus pneumatic brake process is converting the pressure energy of air into mechanical energy of actuator.Bus air brake chamber is the final element of pneumatic circuit,also is the beginning element of the mechanical brake actuator.Pressure characteristic of bus brake chamber is directly related to the performance of bus air brake system.The paper takes the method of theoretical,simulation and experimental researching the pressure characteristics of bus air brake chamber systematically.The main works of this paper are summarized as followed:(1)Combined with the structure of the bus air brake system,analysis the type,structure and working principle of bus air brake chamber.Analysis its role and influence in bus air brake system.Confirm the requirements of bus air brake system to the pressure characteristics of bus air brake chamber referring to the national standard,international standards and related research.Confirm the influencing factors of bus air brake chamber combined with its structure.(2)Simplify the bus air brake circuit for engineering-oriented,establish the pressure characteristics mathematical model of bus air brake chamber in charge and discharge process.The mathematical model mainly consists of pressure change equation of air reservoir,pipeline and brake chamber,flow characteristic equation of brake chamber inlet and relay valve,and the motion equation of piston.Deformation force of rubber and effective pressure area of piston are mainly studied in mathematical model.And build on the MATLAB / Simulink simulation algorithm of the mathematical model of bus air brake chamber pressure characteristic.Obtain the simulation data of bus air brake chamber pressure characteristics.(3)Build the pressure characteristic test bench of bus air brake chamber referring to the national standards and industry standards.Verify the accuracy of the mathematical model and simulation analysis.The test bench consists of hardware systems and software systems.Hardware system mainly consists of air circuit and test circuit designing,test devices selection.Software systems use LabVIEW to design convenient and simple test program to collect,handle and display all kinds of data,for real-time monitoring and subsequent data processing.(4)Contrast test and simulation data of bus air brake chamber pressure characteristics obtained,to verify the accuracy and reliability of test and simulation data.According to the requirements of bus air brake system to the pressure characteristics of bus air brake chamber,combine the test and simulation data analyze the influence of chamber air inlet,chamber initial volume,initial force and elasticity coefficient of return spring to bus air brake chamber pressure characteristics.This paper from the pressure response time,stability and energy efficiency three aspects study the pressure characteristics of bus air brake chamber and its influence factors.This provides a reference for design and selection of bus air brake chamber,provides technical support for the design of bus air brake system,to improve the performance of bus air brake system.