Abstract:In order to solve the problems of high stubble residue in the Huang-Huai-Hai double-cropping area, the stubble-residue is difficult to break in the process of no-tillage sowing of maize, which leads to the winding and congestion of the bed preparation device, thus dragging and pushing soil, resulting in uneven sowing bed and poor sowing quality. Based on the idea of “root stubble cutting, crushing and shifting”, a straw cutting, stubble breaking and seed bed preparation device was designed. The coaxial upper and lower distributed moving and fixed knife combined root stubble cutting device and the root stubble crushing and shifting device were adopted to achieve the cutting of high stubble left above ground and the crushing and removal of root stubble in wheat. Based on the sliding cutting principle, the blade curves of the dynamic and fixed combined root straw cutting cutter and the root stubble crushing and shifting cutter were designed by logarithmic helix and Archimedes helix curve, and the structural parameters of the dynamic and fixed combined root straw cutting cutter and the root stubble crushing and shifting cutter were determined through dynamic analysis. The forward speed of the machinery, the depth of the root stubble crushing and shifting cutter into the soil, and the rotational speed of device were selected as the test factors, and the straw clearance rate of the seed bed and the coefficient of variation of the seed bed width were taken as the test indicators to conduct the three-factor and three-level orthogonal rotation combination test. The regression models and response surface mathematical models of each factor and indicator were established. The test results showed that the optimal parameter combination was as follows: the forward speed of the machinery was 9km/h, the depth of the root stubble crushing and shifting cutter into the soil was 70mm, and the rotational speed of device was 515r/min. At this time, the straw removal rate of the seed belt was 92.59%, the coefficient of variation of the seed belt width was 7.77%, and the machinery pass rate was qualified, meeting the operation requirements of the no-tillage planter for corn in the Huang-Huai-Hai two-cropping area. The research result can provide a reference for the design and improvement of the seed bed preparation device of the no-till seeding machine for corn in plots with high stubble retention.
