倾斜抛物线型孔轮式小麦供种装置设计与试验

Design and Experiment of Inclined Parabolic Cell Wheel in Seed Feeding Device for Wheat

为解决淮北平原玉米秸秆覆盖地小麦播量较大且难以精量控制以及现有小麦集排供种装置结构较复杂的问题,设计了一种具有倾斜抛物线型孔轮式小麦精量供种装置。阐述了该供种装置结构和工作原理,分析并确定了主要相关参数,建立了型孔截面曲线限制方程,构建了小麦充种过程的力学模型,以型孔锥角、型孔轮转速和供种轮数量为试验因素,以供种速率、供种速率稳定性变异系数和种子破损率为试验指标,进行了供种性能试验研究。试验表明:倾角为40°抛物线型孔的供种稳定性较优,其供种速率稳定性变异系数小于1.8%,种子破损率低于0.2%;在型孔轮数量1~5、工作转速10~100 r/min条件下,小麦供种速率随型孔轮数目和转速增加呈上升趋势,其供种速率范围为30~1 500 g/min,供种速率稳定性变异系数随型孔轮数量增加呈下降趋势、随转速增加呈先降后升趋势,其稳定性变异系数均小于2.0%,种子破损率均不大于0.2%;以安装5个抛物线型孔轮供种机构建立单位面积播种量数学模型进行的主动供种匹配试验得出,模拟机组前进速度不大于9.8 km/h时,可实现较大范围的主动供种,其稳定性变异系数均小于2.0%;田间试验得出直播小麦种植密度为230~270株/m2,均匀性变异系数为21.97%。倾斜抛物线型孔轮可实现小麦高速供种并简化供种装置结构。

In order to solve the difficulty of high speed and precision control of wheat in corn straw covered ground of Huaibei Plain and simplify the existing wheat seed supplying pneumatic type mechanism,a inclined parabolic cell wheel seed feeding device for wheat was designed. The structure and working principle of wheat precision seed device was described,the relevant parameters were analyzed and determined,the curve limit equation of cell and the mechanical model of wheat seed supplying process was established,and then taking the cone angle,speed of cell and wheel number as test factors,seed feeding rate,stability coefficient of variation of seed feeding and damage rate were taken as test indexes and a performance experiment was carried out. Experimental results showed that parabolic cell with a dip angle of 40° had better stability,whose stability coefficient of variation of seed supplying was less than 1. 8% and damage rate was below 0. 2%; under the condition that the amount of cell wheel was 1 ～ 5 and working speed was 10 ～ 100 r/min,wheat seed feeding rate,which was ranged from35 g/min to 1 500 g/min,was rising as the number and speed of cell wheel was increased; stability coefficient of variation of seed feeding,which was less than 2. 0%,was decreased as cell wheel number was increased,and it was decreased first and then raised as cell wheel speed was increased; according tothe variable feeding matching experiment with the mathematical model of sowing amount per hectare,which was established by seed feeding device for wheat with the installment of 5 cell wheel,a large range of variable supplying,whose stability coefficient of variation of seed supplying was less than 2%,was achieved when simulation advancing velocity of the equipment was less than 9. 8 km/h. The field experiment showed that the planting density of direct seeding wheat was 230 ～ 270 strain per square,and homogeneity coefficient of variation of seed supplying was 21. 97%. Inclined parabola cell wheel proposed can realize a wide range of wheat seed supplying and simplify the structure of seed supplying device,in order to design a high performance wheat variable seed sowing machine for corn straw mulch in Huaibei Plain and provide the basis.