错位式机采棉秸秆拔取机理分析与机构的研究

The cotton stalk and root is very good biomass raw material but the recycling rate is very low in Xinjiang. The narrow line distance is only about 10 cm in large amount area of Xinjiang cotton harvester machine cropping pattern，and a large number of fracture and leakage occurred to harvest two lines at the same time, which seriously affected the recycling rate of the cotton stalk. In this project, solution will be proposed to adapt the dislocation removal of the stem and the mechanism will be studied. On the basis of determination of the mechanical properties of cotton stalk, the analysis of coupling model modeling will be used to study the coupling characteristics of cotton root and soil, and the multiple physical field coupling effect will be explored between pulling device and cotton stalk - soil composite model. The finite element analysis will be utilized to design the feeding and pulling device, and the motion model will be established and the kinematics and dynamics analysis will be carried on. The dimension, material and working speed of the pulling roller and its belt will be researched to study the influence on cotton stalk removal. The optimal lifting point, pulling force and velocity will be analyzed. The test bench will be set up, and a high-speed camera will be used to analyze the displacement process, motion and the effect. The optimal mechanism and motion parameters will be determined. The project will enrich ultra-narrow line of whole stalk recycling theory, provide theoretical and design reference to new type cotton stalk recycling machine and promote the recycling utilization of cotton stalk on Xinjiang cotton harvester machine.

棉花茎秆与根是很好的生物质原料，但在新疆利用率较低，新疆大面积采用的机采棉种植窄行行距多为十公分左右，两行同时收获会造成棉秆折断或漏拔，进而影响回收率。本项目提出错位“裹持”拔取解决方案，并进行机理及机构的研究，在测定机采棉秆的力学特性的基础上，建立耦合模型研究棉根及土壤结合体的耦合特性，分析起拔机构与棉根-土壤复合模型间的多物理场耦合作用; 利用有限元分析方法设计棉秆导入拔取装置，建立运动模型，进行运动学和动力学分析，研究起拔轮和起拔皮带的结构、材料及工作速度等对拔取棉秆的影响，分析确定最佳起拔点、起拔力和起拔速度; 搭建棉杆起拔试验台，采用高速摄影机分析错位拔取过程、轨迹及效果，确定最佳的机构参数和运动参数。项目的执行可以丰富窄行密植作物的整秆拔取回收理论，能为研制新型棉秆回收机提供理论与设计参考，有利于加速促进新疆机采棉秸秆的循环利用。

针对机采棉“矮、密、早”的种植模式特点，超窄行棉杆距离过近，在拔取中会出现大量的折断及漏拔等现象出现，严重影响棉秆的生物质能源循环利用，本研究在充分研学棉秆起拔收获的基础上，提出错位式无入土部件整秆收获概念，以适应新疆机采棉种植模式为前提，以解决超窄行对棉秸秆回收的影响为目标，运用挤压、裹挟和夹持等原理和技术手段，重点发展无入土部件整秆收获机械设计和改造的新技术、新方法和新策略；通过对棉秆进行物理力学特性试验研究，运用离散元方法对新疆棉花秸秆仿真参数标定，在测量棉秆的直径、株高、根长和含水率等物理特性以及测定棉秆不同部位的抗拉强度、拉伸破坏载荷、横纹压缩强度、以及抗弯特性等力学特性参数的基础上，对棉秆起拔机整机和关键部件进行了设计，确定了棉秆起拔机整机设计方案，建立三维模型，创制了棉秆起拔装置；对棉秆起拔装置进行了结构设计和参数计算，对棉秆起拔装置起拔棉秆的过程进行了受力及运行分析；对产生漏拔和拔断的原因进行了剖析，确定了影响机具作业效果的试验因素，采用正交试验方法开展了田间试验，确定了最佳运动参数和结构参数；本项目的研究有助于开发多种无入土整秆回收机械，满足新疆南北疆各主要棉区棉花秸秆收获工作，为开发棉杆整秆回收机提供理论与设计基础。