Abstract:Corn stalks are stout and non-perishable in Northeast China, which results in the low cutting-out rate and high working resistance torque of the no-tillage planter. To improve the cutting efficiency of corn stalks and stubbles, a dynamic bionic stubble cutting device was designed, which was based on both the multistep serrated mouthpart structure and the moving mode of different-direction isokinetic occlusion. The planetary gear mechanism and bionic cutting disc were designed through bionic-construction, mechanism design, theoretical analysis and parameter optimization;the intelligent driving system was designed by using Arduino system and intelligent control method, and thus the coupling bionic of motion mode and structure was realized. Moreover, the effect of structure and operating parameters, including the number of blades, radius of gyration and forward speed,on the cutting efficiency and working torque was studied via optimization test and regression analysis. The simulation tests results showed that the dynamic bionic stubble cutting device achieved the optimal working efficiency when the machine speed was 10km/h, the radius of gyration was 250mm, the number of bionic locust mouthpart blade in positive rotation cutting disc was 9, and the number of bionic locust mouthpart blade in reverse rotation cutting disc was 18. The comparative tests showed that for the dynamic bionic stubble cutting device, the cutting rate of corn stalks and stubbles were decreased with the increase of machine speed. The cutting-out rate was the highest with a value of 97.1% when the machine speed was 6km/h, while it was the lowest with a value of 92.9% when the machine speed was 10km/h. Compared with the passive notch disc and the driving notch disc, the cutting-out rate of the dynamic bionic stubble cutting device was increased by 22.6%~27.4% and 8.6%~13.5%, respectively. Besides, the cutting torque of dynamic bionic stubble cutting device was decreased with the increase of the machine speed. When the machine speed was 6km/h, the cutting torque was the largest with value of 60.5N·m. Whereas the cutting torque reached the minimum at the machine speed of 10km/h with value of 54.1N·m. The cutting torque of dynamic bionic stubble cutting device was reduced by 19.5%~21.8% compared with the driving notch disc. After the operation, the average surface roughness and the maximum wear scar depth were decreased by 14.5% and 15.9%, respectively, compared with that of the driving notch disc.
