Simulation And Experiment Of Vibration Drag Reduction Of Digging Shovel Of Decursivum Harvester

Fixed digging shovel has problems of large digging resistance and high energy consumption.To solve these problems,the theory based on vibration drag reduction and established of discrete element model for digging shovel.In this paper,EDEM software is used to carry out the vibration mining simulation of the digging shovel,and the methods and ways of drag reduction and consumption reduction of the digging shovel are obtained.A test rig for vibration excavation of soil bin is designed.The effectiveness of discrete element simulation is verified by the actual test in the test rig.The main contents are as follows:1)The soil parameter is measured.The soil physical parameters is measured such as soil texture,moisture content,solidity and wet density.The soil mechanical parameter of cohesion and friction coefficient is measured by triaxial compression test.These parameters are used for the creation of discrete element soil model and soil preparation of soil bin test bench.Through the stress analysis of the excavation shovel,the appropriate entry angle is determined.2)The soil groove test bench was designed.In order to carry out the indoor soil tank test,the vibration structure of the eccentric wheel is designed.The vibration frequency and amplitude can be adjusted by the eccentricity and speed of the vibration mechanism.PLC lower computer control system is designed to control and adjust the traction speed.Appropriate tension pressure and earth pressure sensors are selected to connect the host computer to complete the acquisition and display of the forces in all directions and parts of the digging shovel during the movement.3)Simulation of vibration mining process based on the discrete element method.The model of digging shovel-soil is established,and the EDEM compared high frequency vibration,low frequency vibration and no vibration tests.The results show that the drag reduction effect of high frequency vibration is better and the drag reduction effect of horizontal,vertical and overall force in vibration excavation is 17.4 %,9.6 % and 10.1 %,respectively.In this experiment,the influence of different motion factors on excavation resistance and the drag reduction mechanism of vibration excavation are studied and orthogonal analysis experiment is carried out to obtain the optimal solution for reducing resistance.4)Comparative analysis of soil tank test and simulation test.The drag reduction effect of the optimal combination of motion parameters in the orthogonal test was verified to be27.6 % in the soil tank test.After that,the single-factor experiment were carried out,the comparison between the soil bin test and the simulation test showed that the trend of the traction resistance in the vibration digging test and the horizontal force in the simulation was consistent with the variation of the motion parameters.The above results showed that vibration excavation did have effect on resistance reduction,and its various factors had different effects on the excavation resistance.Vibration mining technology can be simulated by Discrete Element Method.This study provides reference value for the exploration of vibration mining drag reduction technology of similar crop harvesting machinery.