The Research Of Modern Design Method Of Electronically Controlled Hydraulic Retarder Of Vehicle

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.Following items are included in this dissertation:(1) Contrasting the differences of all sorts of auxiliary braking devices, studying principle and application of hydraulic retarder and 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 liquid theory is introduced at first, based on one-dimensional flow theory, braking torque mathematical models of hydraulic retarder are established and the equation between braking torque and rotate speed are deduced; additionally, analyze the liquid flowage quantity in the retarder's circler, set up the equation between flow quantity and rotate speed, effects on braking performance from different oil quantity in the retarder's circler are discussed either. The paper uses measurable geometry parameter and theory to calculate parameter of hydraulicretarder and draw curve of characteristic .(3) Make performance experiments of some type of retarder to verify the test-bed's reliability; deal with and analyze experimental data to calculate the result that the brake performance would be greater when the vehicle with higher velocity and the retarder with more fluid .(4)Two design methods for hydraulic retarder are introduced, including hydraulic calculation method and Similitude Principle calculation method. Base on some type of retarder, we design 3D models of components with CAD software and realize virtual assembly with software.