基于近等速机构的玉米全膜双垄沟穴播机作业性能试验

Operation Performance Test of Hill-seeder Based on Mechanism with Approximate Constant Speed for Corn Whole Plastic-film Mulching on Double Ridges

应用Plackett-Burman试验设计并结合玉米全膜双垄沟穴播机工作原理分析获得的8个初始参数(放大机构比例、近等速机构传动比、成穴器开启位移、成穴器角度、曲柄转速、机器前进速度、主动杆转速、成穴器播深)进行筛选,得到作业机曲柄转速、机器前进速度以及主动杆转速对穴孔错位率、采光面机械破损率影响显著。在通过最陡爬坡试验确定显著性参数最优值区间的基础上,根据Box-Behnken试验结果分别建立了穴孔错位率、采光面机械破损率与显著性参数的二阶回归模型,探究单一因素及交互因素对不同响应值的影响效应,并结合OptimizationNumerical计算方法对直插式穴播机工作参数进行优化与田间试验验证。试验结果表明:样机作业性能在符合国家标准要求前提下,各显著性参数对其穴孔错位率的影响主次顺序为机器前进速度、曲柄转速、主动杆转速;对采光面机械破损率的影响贡献由大到小为机器前进速度、主动杆转速、曲柄转速。优化所得的样机最佳工作参数条件为:机器前进速度为0.52 m/s、曲柄转速为72 r/min、主动杆转速为140 r/min。同时在此条件下,样机田间验证试验的穴孔错位率均值为1.23%,采光面机械破损率均值为9.56%,较优化前穴孔错位率(1.56%~5.87%)、采光面机械破损率(10.63%~73.37%)有明显的下降,表明在优化工作参数条件下作业机能够实现零速投种,基本无穴孔错位与撕膜、挑膜现象出现,能够有效避免对采光面地膜的机械损伤,表明建立的回归模型是可靠的。

The furrow sowing with whole plastic-film mulching on double ridges had been widely used in the arid region of Northwest China,because it could resist drought and increase production. The mechanical sowing with film was an inevitable trend in farming. The working performance of operation machine for direct insert hill-seeder based on mechanism with approximate constant speed for corn whole plastic-film mulching on double ridges was studied,and the best working parameters of prototype,which avoided phenomenon of dislocation of soil hole and mechanical damage of daylighting mulch,were obtained. The Plackett-Burman test was performed to screen the significant parameters from the eight selected parameters( proportion of amplification mechanism,transmission ratio of the mechanism with approximate constant speed,opening displacement of hole-former,angle of hole-former,rotation speed of crank,forward speed of machine,rotation speed of driving lever and planting depth of hole-former). It was found that the rotation speed of crank,forward speed of machine and rotation speed of driving leverhad significant effects on dislocation of soil hole rate and mechanical damage rate of daylighting mulch while the other five parameters' influence was negligible. The steepest ascent test was used to determine the best region of significant parameters. Based on the result of Box-Behnken test, the quadratic polynomial model for dislocation of soil hole rate and mechanical damage rate of daylighting mulch with the three significant parameters were created,the effect of single factor and interaction factors on different response values was explored,and the Optimization-Numerical calculation method was combined to optimize and test the work parameters of direct insert hill-seeder in the fields. The test results showed that the operation performance of prototype was in accordance with requirements of national standard,the effects orders of three parameters on dislocation of soil hole rate were as follows: forward speed of machine,rotation speed of crank and rotation speed of driving lever. The effects orders of three parameters on mechanical damage rate of daylighting mulch were as follows: forward speed of machine,rotation speed of driving lever and rotation speed of crank. The optimal working parameters were machine forward speed of0. 52 m / s,crank rotation speed of 72 r / min and driving lever rotation speed of 140 r / min. Confirmatory tests showed that the average value of dislocation of soil hole rate was 1. 23% and mechanical damage rate of daylighting mulch was 9. 56%,which were dropped significantly compared with before optimization of dislocation of soil hole rate( 1. 56% ~ 5. 87%) and mechanical damage rate of daylighting mulch( 10. 63% ~ 73. 37%). With the optimized working parameters,the threw speed could achieve zero and the problems of picking and tore films and holes with seedlings dislocation were solved, and the mechanical damage of daylighting mulch was also avoided. Meanwhile,it proved that the established regression model was reliable.