The Design And Research Of The Integrated Valve Of The Pneumatic EPB System

At present,pneumatic parking brake system is generally used in commercial vehicles.But commercial vehicles often travel under complicated road conditions,and there are many problems with the traditional pneumatic parking brake system in these cases.Electronic parking brake system,with electronic buttons instead of hand control valve to implementing the electronic control method,can simplify the manipulation of the driver and enhance the safety of vehicles.As the key parts in the pneumatic EPB system,the valve components are mostly installed with the bracket and external pipeline,which are cumbersome,difficult to maintain and occupy large space.To solve these problems,the integrated design concept is adopted in this paper,and the structure model of the integrated valve is built on the basis of 3D software.Then the performance of the integrated valve is further studied,which is of great significance for the development of the pneumatic EPB system.Firstly,according to the relevant laws and regulations and the structure of traditional pneumatic brake system,the paper plans the functional requirements and proposes the overall framework of pneumatic EPB system.Then analyze working principle of the integrated valve and EPB system in detail,laying the foundation for the structural design of integrated valve.Furthermore,the paper puts forward relevant requirements and indicators for EPB integrated valve and carries out the necessary calculation to provide theoretical basis for subsequent parameter design.Based on the structural design requirements of valve components,the design of each component,the construction of 3D model and the final assembly process are all explained.Then in the premise of reasonable hypothesis to establish the mathematical sub-models for EPB integrated valve:electromagnetic field,spool movement,gas path and the piston motion model.The system simulation model is set up in two different simulation environments,AMESim and Simulink respectively.After running,coil current,spool displacement,chamber pressure and other parameters of the results can be obtained to analyze main reasons for the delayed response.At the same time,the simulation results are compared to verify the correctness of the model preliminarily.Finally,through the bench test and co simulation of an other pneumatic EPB system consisting of single valves,the feasibility of using the AMESim/Simulink co-simulation technology to study the integrated valve and EPB system in this subject is verified.Building a joint simulation model,the parameters which have a great influence on the performance are selected and are designed by genetic algorithm.After these,parameters are substituted into the co-simulation model for the comparison.The results show that all the features have improved after integration.