Research On Load-sensing System Of Hydrostatically Driven Rotary Tille

The rotary tiller plays an important role in the process of agricultural production and promotes the development of the modernization of agricultural machinery in China.The transmission mode of the rotary tiller has a decisive role in its driving force and working efficiency,so it is important to study the transmission mode of the rotary tiller.The traditional mechanical drive rotary tiller has a complex structure,high friction loss,and poor control accuracy.Therefore,this paper adopts hydrostatic transmission and control technology to design a rotary tiller quantitative pump electro-hydraulic load-sensitive control system,which is easy to arrange each actuator and has a simple and compact structure,meanwhile,the electric proportional and electronic technology is applied to the load-sensitive system to make it more intelligent and precise in the working process.The thesis mainly accomplished the following research.(1)According to the functional requirements of the rotary tiller,based on the design of the hydrostatic load-sensitive control system drive scheme,for the traditional machinehydraulic feedback load-sensitive system with low stability,low energy utilization and slow response speed,and other shortcomings,innovative design of hydrostatic drive rotary tiller electro-hydraulic load-sensitive control system,and the calculation and selection of system parameters and major hydraulic components,to lay the foundation for the subsequent indepth research of the system.(2)To verify whether the designed electro-hydraulic load-sensitive system of the hydrostatic-driven rotary tiller is reasonable,the dynamic characteristics of the system are studied.Based on the theoretical analysis of the system control scheme and the working principle of the main components,AMESim is used to establish its simulation model,and through simulation experiments,the dynamic characteristics of the electro-hydraulic loadsensitive system of the hydrostatic drive rotary tiller are obtained under various typical working conditions,and the variation law of the output characteristics is further studied.The results show that the electro-hydraulic load-sensitive system can realize the simultaneous compound action of multiple actuators driven by a single dosing pump of the rotary tiller,and has good maneuverability and anti-flow saturation characteristics.(3)To improve the load adaptability and expand the output range of the system,the pressure compensation valve variable differential pressure control and LS main variable differential pressure control scheme are proposed based on the electro-hydraulic load sensitive system.By establishing the system model and solving the model numerically,for the pressure compensation valve variable differential pressure control,the results show that the use of a solenoid proportional pressure compensation valve can realize the pressure compensation valve variable differential pressure control so that the system can improve the speed adaptability of each actuator according to the load requirements.For LS main variable differential pressure control,the results show that the scheme can improve the overall load adaptability,dynamic responsiveness,and output speed range of the electro-hydraulic loadsensitive system of hydrostatic drive rotary tiller.(4)To verify the energy consumption of the designed electro-hydraulic load-sensitive system for the hydrostatically driven rototiller,an energy consumption analysis of the system was carried out.Based on the AMESim simulation software,the energy utilization of the rotary tiller work device system was analyzed when executing individual actions as well as compound actions,and the effect of using LS main variable differential pressure control on the energy efficiency of the system was analyzed in depth.The results show that the energy utilization of the electro-hydraulic load-sensitive system of the hydrostatic drive rotary tiller is higher than that of the conventional fixed-flow load-sensitive system,and the energy utilization of the system is proportional to the actuator load pressure.When the system is in a small flow demand condition,by using LS main variable differential pressure control and reducing the LS preset differential pressure,the energy loss of the system can be reduced,thus improving the energy-saving effect of the system.