Simulation Of Hydraulic Excavator Swing System Based On Secondary Regulation

Hydraulic excavator is a kind of important construction machinery. Although it has many advantages such as large digging force, high working efficiency, strong ability of adapting to working conditions and so on, it also has some disadvantages such as high fuel consumption, poor emissions etc. According to statistics, the total energy of a conventional hydraulic excavator utilization rate is only about 20%. The energy loss during rotation accounts for 25%-40% of the total energy consumption of conventional hydraulic excavator in a working cycle, and most rotary kinetic energy loses through the relief valve, finally dissipating in the form of heat. Therefore, it is significant to study the braking energy recovery of the hydraulic excavator rotary system.To solve these problems, the braking energy recovery of the hydraulic excavator rotary system by using secondary regulation method is researched in this paper. In the process of hydraulic excavator rotary braking, the second element can be switched from the motor to the pump operating mode condition, so it can achieve energy-saving purpose by recapturing a part of braking energy. The main research contents of this paper are as follows:A hydraulic excavator swing system based on secondary regulation technology is built; this paper calculates and matches the parameters of the system by Bobcat435,which is produced in American, as the prototype; at the same time, the simulation model of the whole system via simulation software AMESim is established and mainly the secondary element model, including the valve plate, piston, swash plate, stroke cylinder, electro-hydraulic servo valve etc is built.Speed control of the system and speed step response by PID control strategy are researched and speed step response between Fuzzy PID and PID control strategy are compared;the influence of different external load torque, rotational inertia and the viscous damping coefficient parameters on speed control are qualitative investigated.Based on a typical working condition that the hydraulic excavator slews 90 degrees, the energy-saving simulation of excavator slewing brake energy recovery efficiency is investigated. The results show that the total brake energy recovery efficiency of system can reach 62.4%,and that the hydraulic excavator with secondary regulation technology can save 24.7%. Influence of different rotational inertia, system pressure and accumulator volume parameters on energy recovery efficiency are also qualitative investigated.The relevant results of this paper can provide a theoretical reference for the development of such products and related engineering applications.