Abstract:Aiming at the problems of high power consumption and straw entanglement of rice straw returning to the field, combined with the operation process of the straw returning machine, the reasons of high power consumption and straw entanglement of the straw returning blade before optimization were analyzed, and a kind of reverse rotating deep-buried sliding cutting returning blade was designed. The Archimedes spiral was used to design the side cutting edge of the straw returning blade to improve the sliding cutting performance of the straw returning blade and the dynamic sliding cutting angle of the side cutting edge curve was calculated and verified to meet the condition that the soil and straw slipped out of the straw returning blade. The arc curve was used to design the tangent section of the straw returning blade and the radius of circular arc was determined to be 60mm on the basis of ploughing width and installation angle of tangent section. The EDEM simulation software was used to simulate and compare the straw returning blade with the straw returning blade before optimization. The results showed that the straw returning rate and throwing performance of the reverse rotating sliding cutting returning cutter were basically the same as those of the optimized previous straw returning blade, and the working power consumption was reduced by 18.19%. The stubble height, cutter roll speed and machine forward speed were selected as three factors, and the working power consumption was selected as the evaluation index to carry out the orthogonal test design. Finally, the factors affecting the working power consumption of the straw returning blade from big to small were determined as follows: cutter roll speed, machine forward speed and stubble height. The field test results showed that when the field soil moisture content was 20%~30%, the surface straw coverage rate was 336~353g/m2, the tractor operating speed was 1.5km/h, and the blade roller rotating speed was 250r/min, the operation effect of straw deep-buried sliding cutting returning blade was that the average tillage depth was about 18cm, the returning rate was 87.9%~89.7%, and the surface flatness was 2.1~3.7cm. All the operation indexes met the agronomic requirements of straw returning, and the rationality of simulation test was verified.
