Design And Test Of Electric Self-propelled Cave Digging Machine For Mountain Orchard

China ranks first in the world in fruit production and planting area,among which mountain orchards provide strong guarantee for its good development.However,due to the instability of orchard income,most mountain orchards are in a state of unmanned management and inadequate management.Therefore,there is an urgent need for orchard machinery to replace manual labor.In the daily management of fruit trees,digging and fertilizing is an unavoidable link.At the same time,corresponding fertilizing holes need to be excavated.However,because of the large volume of hanging and traction diggers,they can not adapt to the narrow terrain of mountain orchards;portable diggers need manual handling and completion of digging operations;diggers using gasoline engines as power sources will work on natural rings.Environmental pollution.This paper designs a small electric self-propelled excavator,which has walking power and realizes the automation of excavation process by motor and stroke switch.The main research contents and conclusions are as follows:1)Design of the whole machine.Based on the application environment and agronomic requirements of fruit tree digging and fertilization,the design goal of digging machine is determined,and the design of digging mechanism,automatic lifting mechanism,walking mechanism,supporting mechanism and control system in digging machine is completed.2)numerical simulation of soil cutting process with screw drill.The soil stress concentration around the drill tip and blade is obvious.The maximum cutting power is 0.638 k W by analyzing the cutting power curve,which is 9.3% different from the theoretical calculation.3)Kinematics simulation analysis of excavator operation process.The kinematics simulation analysis of the excavator’s excavation process is carried out by using Pro/E software kinematics simulation module.The results show that the excavator takes 47 seconds to complete a single excavation cycle,there is no interference in the excavation process,and the structure design of the excavator is reasonable.4)Static and modal analysis of drill bit.The static analysis and modal analysis of the main working parts of the drill are carried out by using the finite element software ANSYS.The results show that the stress concentration of the drill occurs at the weld between the auxiliary blade and the main shaft,the maximum deformation of the drill occurs at the outer edge of the main blade and the lower edge of the helical blade,and the structure of the drill is reliable;the natural frequencies of the first eight modes of the drill are higher than their working frequencies,which can be effectively avoided.No resonance.5)Field test of a prototype excavator.The results show that the average effective excavation time of the prototype is 50.7s,1.77 times faster than that of the manual hoe,and the average energy consumption of the single effective excavation is 5.2W.h.The average effective excavation time of the slow excavation is 72.75 s,1.31 times faster than that of the manual hoe,and the average energy consumption of the single effective excavation is 6.38 W.h.The average diameter of fertilization hole is 303 mm,and the average depth of fertilization hole is 393 mm,which meets the requirements of fertilization agronomy;the prototype does not roll over when it works on the slope of 12.3～14.6 and the working process is stable;the maximum speed of the prototype is 1.237 m/s on the rigid road surface,1.202 m/s on the mud road surface,and it can pass through the slope of 14.6 and the transverse slope of 11.6 ～14.3.The walking stability is good.Therefore,the electric self-propelled small excavator designed in this paper has a certain practical value.