秸秆还田机抛撒装置设计与试验

秸秆还田机是将农作物秸秆切碎抛撒还田的常用机械,其作业性能好坏直接影响秸秆还田效果,针对目前还田机抛撒装置普遍存在的调节功能单一、可调角度小及操作繁琐等问题,本文设计了一种还田机抛撒装置。在简述其结构与原理基础上,对抛撒装置零件进行了结构与参数设计,其中导向叶片宽×厚设计为30 mm×2 mm,其后端内、外弧半径为300 mm×330 mm,推杆长×宽设计为863 mm×30 mm,其上相邻孔距为194.5 mm,凸轮长、短半轴长度为145 mm、45 mm,调节轴、套相对可调长度为46.3 mm。应用Solidworks建立了抛撒装置零件模型,根据零件间对应关系进行了虚拟装配,得到了抛撒装置仿真模型,应用ANSYS对导向叶片进行了应力分析,结果表明导向叶片所受最大应力远小于其材料的屈服强度。通过对步进电机输出轴添加虚拟马达、对调节套施加旋转力,实现了抛撒装置左右与上下调节机构的运动仿真。仿真结果表明,建立的抛撒装置零件间无运动干涉,导向叶片左右摆动周期为10.2 s、摆角为+30°～-30°,导流板上下摆动周期为9.9 s、摆角为-15°～+15°,与设计值比较一致,经田间试验可得,秸秆抛撒幅宽、距离的可调范围分别为0～0.69 m、0～0.18 m,所有2因素3水平下的秸秆抛撒不均匀度均小于等于20.26%,符合国标中不高于30%的规定要求,这表明设计的秸秆抛撒装置能够根据作业需要适时调整秸秆抛撒幅宽与距离,进而为类似装置设计与试验提供了参考。

Design and test of spreading device for straw returning machine

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.