| With the increasing awareness of energy conservation and environmental protection,the development of environmentally friendly and energy-saving products has become a trend in the development of engineering machinery.In the current situation of energy crisis and green environmental protection,energy-saving research on hydraulic excavators has become a very promising topic.Hydraulic excavator is a kind of engineering machinery with typical functions,complicated working conditions and wide application.Multi-way valve is one of the main products of energy-saving technology for excavators.Its application has made a qualitative leap in various performances of hydraulic excavators.In this paper,from the perspective of energy loss,the LUDV(Load Indenpendent Flow Distribution)system is used as the research object,focusing on the analysis of the energy saving of the excavator and the optimization of the energy saving performance of the multi-way valve.as follows:1.The significance of energy-saving control of hydraulic excavator is reviewed.The characteristics of various energy-saving systems of excavators at home and abroad are analyzed and compared.The basic structure of excavators and several common working conditions are analyzed.The multi-way valves are described.A key role in the excavator system.2.Analyze the principle of constant power regulation of hydraulic pump and give the mathematical model of hydraulic pump power control,establish the relationship between pressure,flow and efficiency of hydraulic pump.The power adjustment system of the variable pump is analyzed in detail,considering the influence of the compensation valve on the sensitive pump on the system,and a control system transfer function from the power adjustment signal to the power regulating valve and the pump swashplate is established.And finally get a simplified mathematical model of LUDV.3.In-depth study of the principle and internal structure of the main components of the hydraulic excavator load sensing hydraulic system,with the large-scale hydraulic excavator multi-cylinder flow distribution system LUDV as the object,study the flow distribution characteristics and efficiency,analyze the working conditions and the system hydraulic impedance,establish a dynamic model of multi-cylinder "load compensation" loop and AMESim simulation model to understand the internal law and the influence of various parameters on the performance of "load compensation"4.According to the boom lifting action of the actual double-pump combined working condition of the hydraulic excavator,considering the multi-way valve throttle and internal flow passage structure,the FLUENT software is used to analyze the internal flow field of the multi-way valve,and the overall model is studied.The internal flow resistance loss of the road valve and its main occurrence.In view of the cause of the lateral force generated by the fast-lifting double-pump combined with the main part of the resistance loss,the valve body flow path structure is optimized,the flow field calculation and analysis of the optimized flow channel are performed,and the flow resistance in the flow channel before optimization is optimized.Compare.Finally,the existing research contents and research results are summarized,and the future research work is prospected. |
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