The Research On The Braking Control System Of Loader

Brake system plays a very important role in wheel engineering machine. It is a key part for ensuring personal safety and normal operation of wheel engineering machine. At the same time, braking performance directly influences the working efficiency of engineering machine. With the modernization of the industry, wheel engineering machine is developing towards high-speed, heavy duty and automation. So the demand for reliability, controllability, stability of wheel engineering machine's brake system is more and more high. Power brake system is used widely in wheel engineering machine due to its excellent braking performance. At present, most of domestic engineering machine adopt air-over-hydraulic brake system, while general application of full power hydraulic brake system in foreign country. This thesis researches on the two brake systems which are adopted by wheel loader.In Chapter 1, firstly introduces loader's classification, composition and development course. Then, detailedly summarizes brake system's function classification, composition, evaluating indicator of braking performance and the research status in domestic and foreign. At last, describes the research significance and research contents of this thesis.In Chapter 2 and 3, the working principle of air-over-hydraulic brake system, full power hydraulic brake system, the structure and the working principle of important components in two systems are analyzed respectively in detail. Then, mathematic models of these systems are built.In Chapter 4, base on the mathematic models, the simulation models of those two systems are set up on the AMESim simulation platform and some simulation study is done. It primarily concludes that the braking pressure response of full power hydraulic brake system is faster than air-over-hydraulic brake system through analyzing on the simulation results. Besides, the effect on the braking performance with brake pipe is studied.In Chapter 5, experiments of the two systems are done on the CG935H and ZL40F loader respectively. The experimental results are in basic agreement with the simulation results. The simulation models are validated by experiments and can be used for future work. At last, comprehensive comparison of the two systems is done.In Chapter 6, summarizes the research work of the whole thesis and gives a prospect of the next step's work.