Design and optimization of inclined helical ditching component for mountain orchard ditcher

Abstract: There is very few efficient ditchers for ditching in mountain orchard, and the ditchers using now generally waste a lot of power and can't work steadily. To solve these problems, inclined helical ditching component was designed and optimized in this paper. As the key components, helical blade, ditching blades and inserting blade were designed innovatively. Curve of helical blade was conical spiral with equal inclination and variable pitch type, and helix angle of helical blade was 30(. The 3 kinds of ditching blades designed were straight blade, curved blade and toothed blade, the edge angle was 30(, the installation angle was 10(, the bending angle was 45(and the cutting angle was 40(. Edge curve of curved blade was sinusoidal exponent curve and its initial sliding cutting angle was 65(, and the ratio of slip angle increment to polar angle was (0.1. The edge of toothed blade consists of many continuous teeth, its width was 8 mm, back height was 6 mm. general length was 10.4 mm, front end circle radius was 3 mm. Inserting blade was the plane triangle type. Experiments to find 3 kinds of blades' differences and to simulate trenching process were carried out, and influence of ditching parameters on the ditching power consumption was also inspected. Experimental results showed that the ditching power consumption of curved blade and toothed blade were lower and similar, but that of straight blade was higher, when the trench depth was 150, 200, 250, 300 and 350 mm, the ditching power consumption of straight blade was 19.28%, 10.60%, 17.54%, 14.04%, 9.60% higher than that of curved blade respectively, and 19.62%、12.24%、18.26%、16.13%、9.88% higher than that of toothed blade respectively. The ditch depth stability coefficient had little difference, the average ditch depth stability coefficients of straight blade, curved blade and toothed blade were 89.40%, 89.72% and 90.06% .respectivly, the ditch depth stability coefficient of the toothed blade was 0.38% higher than that of curved blade and 0.74% higher than that of straight blade. In terms of ditching power consumption and ditch depth stability coefficient, the number of tooth shaped knives was optimal. Simulation optimization model about toothed blade was established based on response surface analysis method and EDEM software. The optimization results showed that influence on ditching power consumption was in the order of bending angle > edge angle > installation angle > multiple of original tooth, the optimal parameters combination for toothed blade was that installation angle was 4.5°, bending angle was 49(, blade angle was 21(, multiple of original tooth was 1.25, and in this case ditching power consumption was 9.73 kW. The influence on ditching power consumption was in the order of ditch depth > forward speed > ditching speed. When ditching speed was 566 r/min, ditching power consumption power was minimum. and ditching power consumption decreased by 12.80%, groove deep stability coefficient increased by 1.18% compared with before optimiztion, . Compared with the existing ditching machine, the power consumption of this paper reduced by 22.22%, and the gully depth stability improved by 7.2%-8.5%. The research results can provide references for structural design and improvement of ditching component.