基于加捻筒与燕麦草相互作用的单捻制辫成型机理研究

Green grass braid is the most widely used modulation storage form in Qinghai-tibet Plateau. Single twisting braid is one of the core technologies of green grass braid. The working performance of twisting roller directly affects the continuity and twisting quality of green grass braid. In this project, the research objects of studying the relationship between twisting roller and green oat grass. The effect of structure and installation form of shovelling plate on feed is analyzed in order to make sure that green oat grass can be fed into the twist roller smoothly. Based on the analysis of the friction characteristics of the shovelling plate and green oat grass, the mechanical model of the collision is established between the twist roller and the grass bundle, and the effect laws of the structure and motion parameters of the shovelling plate on the force and motion of the green oat grass bundle are obtained. In order to ensure the continuity of single twist braid, by means of coupling simulation, the interaction between external and internal green oat grass, the variation of stress along the cross-section of single twist braid and the interaction between two adjacent bundles of green oat grass are studied in the process of making single twist braid. The structural parameters of the shovelling plate twisting roller are optimized and the twisting performance test is carried out. The successful development of the project will lay a solid theoretical foundation for the design and development of the single twist braid forming machine. It is of great significance for the gain of production and efficiency of forage and the sustainable development of animal husbandry in China.

青草辫是青藏高原地区使用最多的青干草调制贮存形式，单捻制辫是青草制辫的核心技术之一，加捻筒的工作性能直接影响青草制辫的作业连续性和加捻质量。本项目以加捻筒与青燕麦草作用关系为研究对象，通过分析加捻筒的抄板结构和抄板安装方式对喂料的影响，确保青燕麦草顺利喂入加捻筒内；通过分析加捻筒内抄板与青燕麦草的碰撞摩擦力学特性，构建加捻筒与青燕麦草草束的抄草碰撞力学模型，得到加捻筒内抄板结构和运动参数对草束的受力和运动影响规律；通过耦合仿真研究单捻制辫过程中单捻外部青燕麦草与内部青燕麦草之间的相互作用关系，明确草辫单捻过程中一束草沿草辫横截面内应力的变化规律以及单捻制辫过程中相邻两束青燕麦草之间的相互作用关系，确保单捻制辫的连续性；优化抄板式加捻筒结构参数，开展加捻性能试验。项目的成功开展将为单捻制辫成型机的设计与开发奠定坚实的理论基础，对我国饲草增产增效，畜牧业的可持续发展具有重要意义。

青干草草辫或草把子是青藏高原地区牧民使用最多的青干草调制贮存形式，可有效缓解枯草季难以满足放牧家畜营养需求的草畜矛盾。牧区草辫成型主要以手工劳作为主，劳动强度大，工作效率低，牧区劳力不足，无法满足生产需求。前期研究发现，草辫单捻的质量决定了草辫的加工质量，草辫单捻的质量取决于相邻两束草之间的衔接，因此，为确保制辫连续性，解决相邻两束草之间的有效衔接，本项目系统性研究“单捻-合股”分段式青草制辫成型方案，明确了青草单捻制辫成型主要以自由端加捻的成型方案为主，通过深入分析抄板式加捻筒抄板安装方式、抄板结构参数排斥喂料的规律，得出了抄板阻碍喂料主要以不同相位角循环排斥的自然规律，加捻筒转速和喂料速度是影响排斥喂料程度最主要的因素；为实现有效喂料，发明了一种喂量自适应的青草制辫喂料装置；为实现青燕麦草的有效衔接，主要进行了牧草摩擦特性的研究；进行了青燕麦草的压缩特性试验，试验结果显示，压缩力与压缩位移在一元四次多项式关系的情况下，拟合度为99%以上，压力受到位移影响规律呈开口向上的抛物线，可为有效喂料提供理论支撑；为减少喂料加捻过程阻力，实现高效加捻，研制了一种立式单捻制辫成型装置，进行了多因素正交试验，得出喂料辊压力在8-18Kg之间，喂料厚度越大，喂料辊压力越大，加捻扭矩需要达到12N.m以上，在喂料线速度5.97 m/min，加捻转速89 r/min，喂料厚度0.06m的条件下，草辫最大抗拉强度最大为120N，能够满足草辫晾晒不发生破坏的指标要求，实现了在牧草喂入量自适应的情况下连续强制加捻。本项目的顺利开展，丰富了牧草加工技术与理论，加快了青草制辫成型机械化，有效促进牧民增产增收。