Research On Energy-saving Hydraulic System And Control Strategy Of Wheel Loader

Because of its alacrity,adaption to harsh working environment and large loading capacity,the wheel loader is widely used in engineering fields.Thus,its high energy consuming property has gained focus recently,by virtues of the energy saving trends nowadays.The hydraulic systems of working equipment and direction changing equipment are thus objective to study for their low energy utility rate.The objective for energy saving is not only to exploit fuel to its extreme,but also to obtain the result of reducing utility cost.Thus,in this paper,an energy-saving hydraulic system is designed by taking use as auxiliary energy source an accumulator and its control strategy proposed and testified by simulation method,based on the idea of series hybrid vehicles and in joint with ‘Extreme load estimation and intelligent extrapolation optimization of hybrid engineering vehicle in whole working condition' project(National Science Foundation project)The main contents of the paper are as following:1.An energy-saving hydraulic system is designed based on the traditional hydraulic system.In this system two accumulators are added to the original one as auxiliary energy sources,which forms the energy saving system in accordance with such devices as sensors,electromagnetic directional valve and controller.The overall efficiency is obtained by coordinating the powers supplied by motor and needed by load and reducing energy loss from overflow.2.The control strategy is devised with switch and power following control method,because of the short working cycle and obvious working regularity properties of wheel loader and its hydraulic systems.3.The data of pressure,flux,temperature and displacement of piston of the hydraulic systems of working equipment and direction changing equipment are obtained and analyzed to get their efficiency.4.In the joint simulation environment of AMEsim and Simulink,the model is verified by constructing original hydraulic system and contrasting with test data,in combination with the rationale of steering gear,multiple valve and other key components.The types of key components are confirmed.An energy-saving hydraulic system is constructed and its control strategy defined based on primary system and their rationality verified by simulation.The data from simulation and test show that,the efficiency of energy-saving hydraulic system under its control strategy proposed in this paper raises prominently without vitiating the normal function of working and direction changing equipment.