Structural Design And Performance Tests Of Liquid Lubrication Drag Reduction Curved Surface Subsoiler

Long-term tillage,rotary tillage and repeated operations of agricultural machinery,exacerbating the problem of shallowing the cultivated land and thickening the plow bottom of China.Studies have shown that the subsoiling operation can effectively break the bottom layer of the plow,field soil can reach the state of “virtual and real combination”,increase yield up to 5.9%~26.9% for food crops.Subsoiler technology has been promoted by the government.However,subsoiling operation has some problems such as large working resistance,serious wear and tear on equipment,dependence on imports of key components.To deal with these problems of subsoiling operation,scholars at home and abroad has studied the subsoiling drag reduction from different perspectives such as bionics,vibration,surface coating,and achieved good research results.However,at this stage,the problems with subsoiling operation still hinder the promotion,development and popularization of the technology.This paper aims the problems in the process of subsoiling operation at this stage,based on the “13th Five-Year Plan” national key R&D plan project and Shandong key R&D plan project,takes the curved surface subsoiler as the research object and combining agronomic needs,innovates a lubrication and drag reduction subsoiling operation mode.With EDEM software,studied the contact state of the curved surface subsoiler with the soil during the operation,to obtain the main resistance source and the main contact surface with soil.Selection of major components and develop a liquid-lubricated drag reduction curved surface subsoiler.This paper has been field contrast experiments for resistance of two types of subsoiling.The results show that the liquid lubrication drag reduction surface deep shovel has a good drag reduction effect.The main research in this paper includes the following four parts.(1)Analysis of liquid lubrication and drag reduction subsoil operation modeThrough the investigation and analysis of the research status of subsoiling drag reduction and liquid lubrication drag reduction,combined with agronomic demand,proposed a liquid lubrication subsoiling operation drag reduction mode.Designed and fabricated the test samples,did the test in soils with different water content and compactness.The drag reduction effect was between 9-26%,verified the feasibility of the operation mode.(2)Selection lubrication surface of curved surface subsoilerModel the curved surface subsoiler geometric by the 3D scanning system.Using measured soil parameters and related literature to establish the discrete element model of the subsoiler operation process.Analyzed the simulation results,obtain the main resistance source and the main contact surface with soil,compared with the worn curved surface subsoiler,verified the simulation results.(3)Develop the liquid-lubricated drag reduction curved surface subsoilerCombined with the curved surface subsoiler structure performances and working environment requirements,based on the results of discrete element simulation,apply the shark skin shield scale shape and size feature to the curved surface subsoiler lubrication drag reduction design,and finish the processing and manufacturing of lubrication drag reduction curved surface subsoiler.Combined with the interaction with the soil during the operation of the curved surface subsoiler,designed for hydraulic systems;selected,processed and assembled the components of the liquid lubrication drag reduction system and the operating parameter test system.(4)Field performance test and analysisThe field contrast experiments for resistance of two types of subsoiler at the speed of 0.4 m/s,0.8 m/s and 1.4 m/s were carried out in Daan Town,Yanzhou District,Jining City.The results shown that the lubrication and drag reduction subsoiler has good drag reduction effect at various working speeds.The drag reduction effect reaches 13.18% at 0.4 m/s working speed,under the 0.8 m/s working speed the effect is 10.29%,and the drag reduction is 6.50% at 1.4 m/s working speed.Establish the average resistance regression model of the three speeds of the flow rate under the condition of 12 L/min,and carry out the significance test,which indicated that the working speed and the flow rate had significant effects on the liquid lubrication subsoiling resistance.