玉米垄作免耕播种机新型切拨防堵装置的设计与试验

Design and Experiment of Stubble-cutting and Anti-blocking Mechanism for Ridge-till and No-till Planter

免耕播种机田间作业时,根茬堵塞是影响垄作免耕播种机作业效率和播种质量的主要因素,国内外现有破茬防堵装置种类繁多,但适合我国东北玉米垄作区的较少。针对东北保护性耕作区玉米秸秆覆盖量大,根茬粗壮不易破切,致使下茬作物免耕播种时易出现秸秆缠绕和根茬堵塞严重现象,设计一种与中小型玉米垄作免耕播种机配套使用的新型切拨防堵装置,并确定新型切拨防堵装置的主要结构配置。通过对清垄刀的运动学分析,建立清垄刀侧推速度和后拨速度的数学方程,分析得出清垄刀配置偏角与机具前进方向为30°时,可以满足保护性耕作的清垄要求;通过对破茬犁刀工作状况分析,取配置偏角为6°时,不仅可将玉米根茬的根上节劈开,还可为后续的播种开沟器提供一个良好的工作环境,有利于保持播种深度的均匀性。为确定该装置合理的作业参数,采用二因素三水平正交试验方法,以机具作业速度及配重为影响因素,以切茬深度和牵引阻力为评价指标进行试验研究,并进行田间验证试验。试验结果表明:当机组作业速度5km·h-1,配重113kg时,切茬深度为84.4mm,牵引阻力为0.96k N,能够有效切断并清除玉米根茬,创造良好的种床,动力消耗小。该研究可为东北保护性耕作区玉米垄作免耕播种机的整机改进设计提供理论参考。

When no-till planter works in the field, residue blocking is the main factor that influences working efficiency and seeding quality. There are many kinds of stubble-breaking and anti-blocking device, but few applies to the Northeast ridge zone in China. In view of the phenomenon that straw winding and residue blocking between units which were caused by large amount of corn straw and stubble in this area, a new type of anti-blocking mechanism for ridge till and no-till planter was researched and designed and its main structural configuration was analyzed and determined. Through kinematics analysis of the ridge cleaning knife, in this paper, the mathematical equation of lateral velocity and behind direction velocity were established. When the configuration angle is 30°, the ridge-cleaning device can meet the requirements of conservation tillage and ridge-clearing. Through the analysis on the working condition of the stubble breaking coulter, when the configuration angle is 6°, stubblecutting disc not only can split corn stubble root section, but also can provide a good working environment for the subsequent seeding furrower, which is conducive to maintaining the uniformity of seeding depth. Orthogonal experiment of two factors with three levels was conducted to find out its reasonable operation parameters. The travel speed and pullback weigh were selected as factors, and stubble-cutting depth and draught resistance were selected as evaluation indexes to study its working performance. Field verification experiments indicated that stubble-cutting depth and draught resistance were 84.5mm and 0.96kN respectively when travel speed was 5km.s^-1, and pullback weigh was ll3kg, the mechanism could effectively cut off and remove corn stubble, create a good seed bed. In addition, its power consumption was small. This study provides a reference for the design of no-till planter in the Northeast ridge zone in China.