| As a common type of construction machinery,excavator economy and maneuverability have always been the focus of the mechanical industry.The power matching method between the diesel engine with mechanical speed regulation and the hydraulic system with open center is widely used in excavators produced by domestic main engine manufacturers.Compared with mechanical governor diesel engine,electronic control diesel engine have better speed regulation characteristics and energy saving effect,and the closed center hydraulic system can avoid unnecessary air flow and throttling loss compared with the open center hydraulic system.Therefore,it is of great significance to study the power matching between electronic control diesel engine and closed center hydraulic system.Combined with the school-enterprise cooperation project "FW80 full hydraulic crawler excavator development"(project no.FW/RD201717),this paper studied the characteristics of its hydraulic system and engine,and analyzed the reasons for its power loss.By studying the principle and method of power matching of excavator,the paper puts forward the strategy of control under different working conditions.Through the method of software simulation and experimental research,the energy-saving effect of power matching in different operating conditions is studied.The following is the main research from the following aspects1.The research status of hydraulic control system and power matching technology of excavator was summarized through extensive reading of relevant literature.Through the analysis of Lastdruck unabh?ngige Durchfluss verteilung 's working principle and characteristics,the load sensitivity and anti-saturation characteristics of Lastdruck unabh?ngige Durchfluss verteilung are defined,that is,the pressure and flow of the hydraulic system are suitable for the demand of the load,and when multiple actuator compound action,the flow distribution is not affected by the load,to ensure the coordination of the compound action.2.Compared with the mechanical governor diesel engine,the electronic control engine has better speed regulating characteristics and higher combustion efficiency.There are many working conditions of the excavator,and the load pressure changes dramatically in the working process.Based on the analysis of the engine characteristics,the electronic control diesel engine has better performance than the mechanical governor diesel engine,and the engine speed can be stabilized near the set speed.3.Engine power matching method was studied.In this paper,power matching was carried out from two aspects: pump-load and engine-pump.Electronic control diesel engine and constant power variable pump realize constant engine speed control through the electronic control unit of the electronic control diesel engine.By controlling the engine throttle,the engine torque is changed,and the output power of the engine is controlled to realize the matching between the engine and the pump.4.On the platform of AMESim simulation model of hydraulic system is established and the working condition and control model,established in the ADAMS dynamics simulation model of excavator working device,through the joint simulation method,the simulation of the single action and compound action cylinder pressure curve,in the cases of constant power of pump characteristic curve and the working condition and control flow.The comparative analysis with the experimental results can verify the correctness of the simulation model and lay a foundation for the future research.5.Design the full cycle operating condition of the excavator and measure the engine speed and load pressure.It can be found that the engine speed remains stable at the set speed when the load pressure changes dramatically.By analyzing the energy consumption of the prototype in full cycle operation,the effectiveness of power matching in different working conditions can be verified. |
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