Study On Tracked Micro-rototiller And Working Parts

The quality of soil cultivating significantly influences on crop output as well ascrop properties. In thus, to design and research on a kind of tilling machine is of vitalimportance with respect to not only improving soil condition, production, and alsodecreasing energy consumption and optimizing agricultural power management. Inorder to address such problems of the micro-rototiller as inadequacy in engine poweradaption ability, poor operation quality and so forth, this dissertation is to study on asmall-scale power chassis with muti-functional ancillary equipment. Based on thetheories of vehicle-terramechanics and mathematical models of the travelingmechanism concerning both with kinematics and dynamics, power performance andtraction capacity could be analyzed and thus improved. Having the workingparameters calculated, prototype machines are to be manufactured for field orthogonalexperiment and regression experiment, through which dynamics parameters could bevalidated and optimized.Detailed research contents and methods are as following:1. To design a double-track power chassis with low transmission position, whichtravels in each field ditch so that overall machine size could be reduced withoutweakening its operating stability, field trafficability and landform adaptability.2. Based on modular design modeling method of virtual prototype technology,entity models, virtual assembling and motion interference analyzing of each parts arecarried out in3D (3-dimensional) designing software. In thus, the structural rationalityis guaranteed and model files for finite element analysis are provided. Through volumeproperties of the virtual prototype of tracked micro-rototiller, ground pressure of thetrack unit is validated and unnecessary experimental prototype is saved to improve theefficiency of machine design.3. By analyzing the stress nephogram and USUM displacement nephogram of thefinite element analysis result, the dimensional parameters of rotary blade is optimized.In order to reduce the weight of the micro-rototiller, nylon was chosen as the material for track driving wheel, and strength analysis was therefore carried out by means offinite element analysis to ensure that nylon wheel won’t fail under both commoncondition and extreme working condition. Modal analysis was researched on enginecarrier. The result showed that the first five inherent frequencies of the engine carrierare all beyond engine oscillation frequency, so that the occurrence possibility ofsympathetic vibration for engine carrier was diminished.4. Prototype machines were manufactured for field experiments. Taking thepower chassis and rotary tilling parts as a whole research object, track slippage rate asthe orthogonal experimental indexes, while blade shaft rotary speed, unit forwardspeed, and machine weight as the orthogonal experimental factors, the orthogonalexperiment is performed. According to orthogonal experiment data processing,influence primary sequence of experimental factors is obtained in range analysis asfollowing: blade shaft rotary speed influences on track slippage rate most notably,followed are interaction effect between blade shaft rotary speed and unit forward speed,unit forward speed, and machine weight as the least notable factor; the optimal factorcombination were specified as blade shaft rotary speed equals120r/min, track drivingwheel rotary speed equals60r/min，and machine weight equals120kg. In varianceanalysis of orthogonal experiment, the result was reached as following: blade shaftrotary speed is notably correlated with the track slippage rate at the possibility ofα0.05, while the interaction effect between blade shaft rotary speed and track drivingwheel rotary speed is correlated with the track slippage rate at the possibility of α0.1.According to orthogonal experiment variance analysis, quadratic regressionexperiment was done with track slippage rate and soil breaking rate as experimentalindexes and blade shaft rotary speed, track driving wheel rotary speed as theexperimental factors. Based on MATLAB experimental data were processed and factorinfluential law as well as the regression equation was achieved and optimumparameters are predicted as a result as following: when blade shaft rotary speed equals200r/min, and track driving wheel rotary speed equals45r/min, the optimal trackslippage rate equals4.9944%and soil breaking rate equals86.9535%.