关键词: 秸秆还田机, 抛撒装置, 调节机构, 零件设计, 建模仿真, 田间试验

Abstract: Straw returning machine is a common machine for chopping and spreading crop straw back to the field. Its operation performance directly affects the returning effect of crop straws.Aiming at the problems such as single regulating function, small adjustable angle, and complicated operation, which are commonly existed in the spreading device of straw returning machine at present, a spreading device of returning machine was designed in this paper. After briefly describing its structure and principle, the structures and parameters of the spreading device parts were designed.The width×thickness of the guide blade was designed to be 30 mm×2 mm, the inner and outer arc radii of the rear end were 300 mm×330 mm, the length×width of the push rod was designed to be 863 mm×30 mm, the adjacent hole distance was 194.5 mm, the length of the oval cams long and short half axes were 145 mm and 45 mm, and the relative adjustable length of the adjusting shaft and sleeve was 46.3 mm. The component models were built by applying Solidworks. After virtual assemblies were carried out according to the corresponding relationships between parts, the simulation model of the spreading device was obtained, and the stress analysis of the guide blade was carried out usingANSYS. The result showed that the maximum stress on the guide blade was far less than the yield strength of the material. By adding a virtual motor to the output shaft of the stepping motor and applying a rotational force to the regulating sleeve, the motion simulations of leftright and updown regulating mechanisms of the spreading device were realized.The simulation results showed that there was no motion interference between the parts of the spreading device.The leftright swinging period of the guide blade was 10.2 s,the swinging angle was +30° to -30°, the updown swinging period of the guide plate was 9.9 s, and the swinging angle was -15° to +15°, which were consistent with the design values. It could be obtained through the field test that the adjustable ranges of the straw scattering width and distance were, respectively, 0-0.69 m and 0-0.18 m.The unevenness of straw scattering under all twofactors and threelevels were less than or equal to 20.26%.It met the requirement of no more than 30% in the national standard.This indicated that the designed straw scattering device could adjust the width and distance of straw scattering according to the operation needs. It provided a reference for the design and test of a similar device.

Key words: straw returning machine, spreading device, regulating mechanism, component design, modeling and simulation, field test