山地果园开沟机倾斜螺旋式开沟部件设计与优化

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

为缓解中国山地果园开沟施肥作业中,可用开沟机型短缺、已有开沟机型普遍存在开沟功耗高、开沟稳定性差的问题,该文设计并优化了山地果园开沟机倾斜螺旋式开沟部件,进行了直刃刀、曲刃刀与齿形刀对比试验和齿形刀开沟刀片结构参数优化仿真试验。为验证优化效果及分析作业参数对开沟功耗的影响,进行了开沟作业参数对开沟功耗影响试验。试验结果表明:开沟功耗方面曲刃刀与齿形刀较优且差异不大,直刃刀较差;开沟沟深稳定性方面3者比较接近。利用响应面分析方法和EDEM软件建立了齿形刀结构参数优化仿真模型,仿真结果表明:对开沟功耗影响显著顺序为折弯角>刃角>安装角>齿形。优化后结构参数为安装角4.5?,折弯角49?,刃角21?,原齿倍数1.25,对应开沟功耗为9.73kW。对开沟功耗影响显著顺序为沟深>前进速度>开沟转速;转速为566r/min时,开沟功耗较低。优化后开沟功耗降低12.80%,沟深稳定性系数提高1.18%。对比现有开沟机,开沟功耗降低22.22%,沟深稳定性系数提高7.2%～8.5%。研究结果可为山地果园开沟机开沟部件结构设计和开沟刀片结构参数优化提供参考。

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.