| At present,China’s agricultural development is facing new requirements,new opportunities and new challenges,in order to meet the requirements of conservation tillage put forward by the state,it is necessary to further improve and innovate the existing rotary tillage device.Aiming at the technical mode of wide and narrow row operation of protective tillage straw in the central region of Jilin Province,China,with a soil depth of not more than 10 cm and a soil moving rate of not more than 50%,this paper studies and designs a vertical strip rotary cultivator,which can not only meet the needs of operation,but also adapt to the freezing of soil surface in the early stage of autumn or spring plowing,including the following studies:(1)Research on soil characteristics of strip tillage: The soil characteristics research in strip tillage operation includes the determination of soil bulk density,moisture content,firmness,texture and direct shear test,which provides an important reference for subsequent simulation tests and soil trough and field verification tests.(2)Design of vertical strip rotary cultivator and ANSYS finite element quality check simulation test: The design of vertical strip rotary cultivator mainly includes the three-dimensional structure design of five parts: frame,transmission mechanism,pressing mechanism,vertical shallow rotary knife roller mechanism and depth limit wheel,among which the vertical shallow rotary knife roller mechanism also carried out knife group arrangement design and kinematic analysis,and designed three vertical blades with different soil entry angles to cope with the freezing of the soil surface in autumn ploughing or spring ploughing,and the soil entry angles were 30°,45°,and 60°,respectively;The repression apparatus was also equipped with a hydraulic motor to drive the repression wheel to rotate,matching the forward speed of the tractor and obtaining a better suppression effect;The transmission mechanism is also designed with a transmission ratio to check the strength of the central gear to meet the working requirements.ANSYS finite element quality check simulation tests mainly include quality checks of cutterheads and insert assemblies to ensure that the quality of the toolholder and blade welds passes;The static simulation check and modal analysis of the frame confirmed that the strength and stiffness of the frame were qualified,and there was no bending or fracture during operation,and no resonance phenomenon.(3)Performance test of vertical strip rotary cultivator: The test content of this paper includes two parts: simulation test and verification test.The vertical shallow rotary cutter roller mechanism and the pressing mechanism were introduced into the EDEM model,and the EDEM discrete element simulation test was obtained by taking the forward speed,knife shaft speed and blade entry angle as the influencing factors of the test,soil fragmentation rate,soil flatness and soil bulk density as the test indicators,and using the Design-Expert software to optimize the test data,and the best data combination of forward speed,knife shaft speed and blade soil entry angle was obtained.The best data combination was used to verify the soil trough test and collect data against the vertical shallow rotary knife roller mechanism,and the final result was that the soil crushing rate was 87.374% and the soil bulk density was 1.066 g.cm-3,which could meet the requirements of modern agricultural machinery.Finally,using the best data combination,field verification tests and data were collected for the suppression agency,and the final results were that the average flatness was 11.222 mm and the average firmness was 94.87 Kpa,which could meet the needs of mechanized operation. |
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