Research On Characteristic Of Pressure Valve In Peneumatic System Of Electronic Control Hydraulic Retarder

With the developing of domestic traffic, the status of traffic and traffic capability of vehicle has improved greatly, the load and quantity of commercial vehicle is demanded much more either. The performance of vehicle has been improving, including average velocity and the power of engine, while no perfect breakthrough on the vehicle brake performance all over the world. For the limitation of brake system dimension and cooling system capability, the accumulation of heat produced by brake system results in safety question of drivers, occupants, pedestrian and vehicle.The vehicle must be equipped with auxiliary braking system besides the service brake to ensure the well brake performance. As a kind of auxiliary brake system, hydraulic retarder can reduce the load of the service brake, make vehicle slowdown smoothly, enhance the reliability of the brake system, and reduce the traffic cost greatly. The hydraulic retarder is very suitable for continuous braking since it has many advantages such as: durable performance, high braking power and good quality of control, the development prospect of it is promising. Research and application of hydraulic retarder has been deeply investigated abroad, while theory research and samples development just begin in china.The main purpose of this paper is to study on the characteristic of pressure valve in pneumatic system of electronic control hydraulic retrader,make a model for pressure valve using matlab software and do some experiments. This paper give the reference to research on hydraulic retarder and methods for factories developing and manufacturing hydraulic retarder.Following items are included in this dissertation:(1) Contrasting the differences of all sorts of auxiliary braking devices, studying principle and the strongpoint of hydraulic retarder. the application of hydraulic retarder ,introducing the proportional pressure valve, then putting forward to the emphasis of the paper based on the hi-tech project of the Science and Technology committee of JILIN province.(2) The theory for the design of hydraulic retarder is introduced, two designmethods for hydraulic retarder are introduced, including hydraulic calculation method and Similitude Principle calculation method. Introducing modern design methods through CAD technique.(3) Studying the components and structure of hydraulic retarder ,and based on this we analyze the pneumatic system of hydraulic retarder,introdcing the components of pressure valve and the function in the pneumatic system.(4) Analyzing the structure , the control signal, the characteristic of pressure valve, a model for pressure valve using simulink software is built, and then do some dynamic simulation.(5) Make experiments both on proportional valve and on/off valve,analyze the results and draw curve , proof the correctness of the simulation modol. Make performance experiments for hydraulic retarder ,analyze the working state of the pneumatic system in hydraulic retarder, analyze the results and draw curve.Through the analyse of pneumatic system of electronic control hydraulic retrader,foucs on the characteristic of pressure valve,build model for simulation and make experiments. We conclude that the characteristic of pressure valve satisfy the demand of pneumatic system,control the pressure of pneumatic system,supply the brake moment at a short time and keep it,make sure the safety of vehicle.