玉米秸秆垄沟条带混埋还田机的设计与试验

Design and Experimental Study of Maize Straw Ridge-furrow-strip Mixed Burying Machine

为了满足东北地区旱地合理耕层构建技术的要求,改善土壤耕层结构,实现秸秆混埋还田,研制了一种玉米秸秆条带混埋还田机。该机具主要由限深破茬装置、弹齿清垄装置、深松装置、混拌装置、镇压装置等组成,可以同时在三个垄沟内将地表上的秸秆混埋于15～20cm深度的土壤中,同时完成清垄、深松、镇压等多项作业,适合东北棕壤土区旱地合理耕层的构建技术要求。通过对弹齿清垄装置的运动轨迹分析得出,当机具前进速度范围在1.1～1.6m·s^(-1)时,弹齿清垄器的弹齿端部的绝对速度为1.73～2.51m·s^(-1),弹齿的拨草范围角为46°。通过对混拌装置的运动轨迹分析得出,当机具前进速度为1.38m·s^(-1)时,混拌刀切土节距为4.6cm,单条混拌幅宽为350mm,混拌刀辊的转速为300r·min^(-1)。并根据切土节距和混拌耕深设计了一种C型混拌刀,通过分析计算得到了C型混拌刀的各项参数以及侧切刃的阿基米德螺线方程。利用二维软件CAXA和三维软件Solidworks对混拌刀进行参数设计和实体模型的建立,同时利用ANSYS Workbench对所设计的混拌刀进行静力学分析来验证混拌刀结构的合理性。通过Design-expert软件对田间试验数据分析得出各因素对田间秸秆混埋率的影响主次顺序为:混拌深度>秸秆覆盖量>机具前进速度。最佳试验条件:在机具前进速度为1.25m·s^(-1),混拌深度为17.5cm,田间秸秆覆盖量为0.93kg·m^(-2)的条件下,秸秆混拌率为94.6%。该试验结果验证了机具作业性能达到了设计要求,为条带秸秆还田机的改进设计提供理论和实践参考。

In order to meet the requirement of reasonable plough layer construction technology、improve soil plough layer structure and realize straw mixed-buried returning in Dryland of Northeast China,a corn straw strip mixed-buried returning machine is developed.The machine is mainly composed of stubble cutting device,ridge cleaning device,subsoiling device,mixing device,and compression device.It can simultaneously bury the straw on the ground in the soil of 15-20 cm depth in three ridges and furrows.At the same time,it can complete ridge cleaning,subsoiling,compression and other operations.It is suitable for the technical requirements for construction of rational cultivation layer in the dryland of the brown loam region of northeast China.Through the motion trajectory analysis of elastic tooth which is key part,getting the motion parameters and structural parameters of the cleaning device:when the speed range of the machine is 1.1-1.6 m·s^-1,the absolute velocity range of the end of the elastic tooth clearance device is 1.73-2.51 m·s^-1,the angle rangeФ1 of the elastic tooth is 46°.Through the motion trajectory analysis and the structural parameter analysis of the mixing device,we get the following results:when the speed of the machine is 1.38m·s^-1,the mixing pitch is 4.6cm.The mixing width is 350 mm,and the speed of the mixing cutter roller is 300 r·min^-1.And a kind of C-type mixing cutter is designed according to cut soil pitch and mixing depth.Through analysis and calculation,the parameters of the C-type mixing cutter and the Archimedes spiral equation of the side cutting edge are obtained.Two-dimensional software CAXA and Three-dimensional software Solidworks are used to design the parameters and establish the solid model of the mixing cutter,at the same time,ANSYS Workbench is used to carry out static analysis of the designed mixing cutter to verify the rationality of the mixing cutter structure.Through the analysis of the field experiment data by Design-expert software,it is concluded that the order of the factors affecting the rate of straw mixing is:Mixing depth>Straw mulching>Speed of machine tool.The optimum test conditions were as follows:the mixing rate of straw was 94.6%under the conditions of 1.25 m·s^-1,17.5 cm mixing depth and 0.93 kg·m^-2 straw coverage.It is verified that the performance of the machine meets the design requirements and provides a theoretical and practical reference for the improved design of straw returning machine.