Design and experiments of active anti-blocking device with forward-reverse rotation

Conservation tillage has been a widely defined practice to maintain crop residues on at least 30% of the soil surface after tillage activities, in order to increase soil organic carbon and microbial biomass for less soil erosion in sustainable agriculture. However, a furrow opener of sowing can be twined and clogged by surface crop residues, leading to seed exposure and break ridge in fields. Furthermore, the current no-tillage seeder equipped with an anti-blocking device cannot fully meet the large crop residues with the whole straw coverage on the small plot in Southwest China. In this study, an active anti-blocking device with down-cut and up-cut was designed for the maize no-tillage planter using the support cutting principle. The bionic enlightenment of the anti-blocking device design was obtained from the movement mode and morphological structure of Batocera Horsfieldi. The profile curve of Batocera Horsfieldi mouthpart was extracted as the cutter edge of the right and left disc coulter using image processing. The parametric equation of the left and right disc coulter teeth was established using the fitting curves. A solution analysis was used to determine the functional relationship of tooth number and tooth height of the left and right disc coulter, according to the geometrical relation. A mechanical model of cutting straw was established to reveal the anti-blocking mechanism. A kinematic analysis was implemented to obtain the motion trajectory of the blade tip in the left and right disc coulter. The discrete element method (DEM) was selected to simulate the operation process of the anti-blocking device. A Hertz-Mindlin with a bonding contact model was also established for the crushable corn straw under EDEM software. Furthermore, the single-factor experiment demonstrated that the down-cut disc coulter was in the right disc type, and the number of teeth was 9. A quadratic regression rotatable orthogonal experiment was carried out to obtain the optimal parameter combination. Specifically, the forward speed, spacing, down-cut speed, and up-cut speed were taken as experimental factors, whereas, the number of broken bonds and power were as the experimental indexes. The Design-Expert was selected to establish the regression model for the number of broken bonds and power. A variance analysis showed that the forward speed presented an effect (0.01