圆盘破茬刀切割玉米根茬运动特性测绘装置设计与试验

免耕播种机是保护性耕作的关键机具之一,其播种质量的好坏在很大程度上影响着保护性耕作的效果。为了优化免耕播种机的关键部件破茬刀,研制了一种圆盘破茬刀切割玉米根茬运动特性测绘装置,该装置能够实现实时地测绘出圆盘破茬刀待测点的运动轨迹。通过对三种圆盘破茬刀的运动轨迹的测绘与试验,得出光面圆盘破茬刀上待测点的运动轨迹为光滑的摆线,半圆型缺口盘和阿基米德螺线盘上待测点的运动轨迹为由不同长度的圆弧组成的云曲线。在此基础上对三种圆盘破茬刀冲击情况、入土滑切角和滑切速度变化进行了分析比较,建立了阿基米德螺线型圆盘破茬刀切割根茬运动的运动学模型。描绘出阿基米德螺线型圆盘破茬刀刃口上点的运动轨迹是由不同长度的圆弧组成的云曲线,建立了阿基米德螺线型圆盘破茬刀刃口上点的运动方程。发现阿基米德螺线型圆盘破茬刀刃口上点的轨迹具备了光面圆盘破茬刀的摆线规律,也具备了半圆型缺口圆盘破茬刀的冲击性,并且滑切角较大,滑切性能更好。通过圆盘破茬刀切割玉米根茬运动特性测绘装置的两因素三水平正交试验分析,得出阿基米德螺线型圆盘破茬刀、机具配重为100 kg时破茬效果达90%以上,破茬率较高。

Design and experiment of the surveying and mapping device for the movement characteristics of corn stubble cutting with disc cutting knife

No-till planter is one of the key equipment of conservation tillage, the seeding quality greatly affect the development of conservation tillage. In order to optimize key components of no-till planter, we developed a disc stubble knife cutting corn rootstalk motion characteristics testing device. The device can realize real-time mapping of disc coulter work when measured point trajectories. Through the mapping and test on the three kinds of disc stubble knife trajectory, inferred that the movement track of smooth disc broken stubble knife''s stay measuring points was smooth cycloid, the movement track of semicircular type gap disc and Archimedes spiral disc''s stay measuring points was cloud curves by different length of arc. Based on the above mention, make the kinematic analysis on three disc cutting knives, impact situation, buried slip angle and cutting speed changes were respectively analyzed and compared. To establish a stubble breaking cutter cutting stubble movement kinematics model with Archimedes spiral disc type. Depict the Archimedes spiral disc broken stubble blade mouth point trajectory was composed of different length of the are cloud curve and to establish a broken stubble blade mouth point equations of motion with Archimedes spiral disc type. Found the track of the knife-edge points on linear Archimedes screw disc stubble has the cycloidal law on the smooth disc stubble knife, but also has the impact on the semi-circular notch disc stubble knife, and the sliding cutting angle bigger, sliding cut performance better. Through the disc break stubble cutter cutting corn root stubble motion characteristics testing device of 2 factors 3 levels orthogonal test analysis, that Archimedes spiral disc type stubble breaking cutter, machine counterweight to 100 kg breaking stubble is best, stubble breaking rate is high.