Design Of A Soil Resistance Test Platform For Small Soil Contact Parts

Soil trough test-bed can simulate soil properties such as soil firmness and water content in the field,and can effectively control the traction speed,depth and speed of the tested parts.It can accurately test the parameters of tension,torque and deformation of agricultural machinery during walking.However,the existing soil trough test equipment is heavy,heavy in soil,large in energy consumption and noise,and it is not convenient for small-scale soil-touching parts to repeate tests.According to the design standard of "Mechanical Design Manual",this paper designs a general platform for the test and research of small soil-touching parts by using modern design method.The main research contents are as follows:(1)The overall design requirements of the test-bed are put forward,and its basic design parameters are determined.Through multi-scheme design and research,the optimal scheme of track and wheel set and the structure scheme of the test-car are finally determined to meet the design requirements,and the force measurement method of sensor redundancy is proposed.(2)The design parameters of leaf spring under different working conditions are determined by virtual prototyping technology,and the key components are designed in detail.(3)External hoisting drum wire rope traction is used as the driving device of the test vehicle.The drum and wire rope are designed and calculated;and the tensioning device is designed.(4)A multi-sensor force measurement scheme is proposed to detect the force exerted on the soil-touching parts,and the design of the force measurement structure is completed.The correctness of the multi-sensor force measurement scheme is verified by theoretical derivation,and the calibration equation of the force measurement system is calculated by the classical least square method.The scheme avoids the influence of the installation accuracy of sensor connection components on the accuracy of measurement parameters,and effectively improves the measurement accuracy.(5)Finally,the design results are simulated by virtual prototype test,and the feasibility of the design results is preliminarily determined.The appearance size of the test vehicle is determined to be 1100 mm x 1400 mm x 350 mm by the design of the test platform of the soil tank with the help of computer aided design.The test vehicle adopts the support form of the pre-tightened leaf spring wheel setand the front and rear wheel spacing is 977 mm.The feasibility of the multi-sensor force measurement scheme is preliminarily verified.The mechanical analysis of the key parts of the machine is carried out through finite element analysis to ensure that it can meet the design requirements.Based on the design of soil tank test-bed,the application of computer aided design method in agricultural machinery equipment was explored.