芦苇打包机关键机构设计及其仿真分析

发布时间：2018-06-18 23:51

本文选题：芦苇 + 打包机　；参考：《石河子大学》2014年硕士论文

【摘要】：芦苇是作为造纸的非木材纤维优质原料,也是我国造纸工业的重要原料之一。芦苇产区距造纸企业路途遥远,不断提高的运输成本已成为疆内造纸企业扩大规模提高效益遇到的主要瓶颈之一,将芦苇打成高密度包是降低运输成本的有效方法,而芦苇打包密度与打包机的工作性能密切相关,故本文主要对高密度芦苇打包机关键机构展开研究和分析,主要内容包括： (1)通过对影响芦苇压缩密度的因素进行分析,采用闭式压缩方法针对影响压缩密度的喂入量,压缩速度和含水率三个因素进行压缩试验,得到影响芦苇压缩密度的因素显著程度从大到小依次为喂入量、压缩速度、含水率。在实验环境下喂入量为550g,压缩速度在10mm/min,含水率为17%时可获得较优的压实效果。试验结果表明在实际打包过程中,在一定范围提高喂入量,优先采用低水平压缩速度和高含水率可提高打包密度。 (2)通过分析芦苇打包机在工作过程中的功能要求对关键机构——喂入压缩机构进行设计并建模；计算确定偏心距、曲柄和曲柄连杆长度分别为130mm,273mm和1048.5mm,并通过验证最小传动角证明设计合理；对喂入压缩机构进行了运动学和动力学仿真分析,得到二者在相互协同配合时的位移和速度变化情况以及关键零部件之间铰接处受力情况；喂入动作与压缩动作顺序时差为0.085秒,配合精度符合要求；获得喂入机构中拨叉的扫掠轨迹和喂料拨叉在XY平而内四个外廓极限位置,扫掠而积在0.1m2至0.2m.2之间；在拨叉喂入最高点处,拨叉曲柄与拨叉套轴铰接处受力最大,最可能发生失效或破坏。 (3)基于有限元方法并利用Ansys软件对关键零件曲柄连杆进行模态分析,提取并分析了曲柄连杆前10阶自由模态和约束模态的固有频率和振型,分析结果表明,曲柄连杆在实际工作过程中变形可能性较大的位置为连杆中心及中心对称的两侧位置。在ADAMS中建立压缩机构的刚柔混合模型,对刚性模型和刚柔混合模型的速度和受力进行对比分析,其分析结果表明,刚柔混合系统在系统启动时速度和力值波动均较大,持续时间约为0.05秒,稳定后与刚性系统的运动规律和受力情况基本吻合,最大幅值处相差幅值不超过0.5%；仿真结果表明曲柄连杆柔性对系统影响较小,刚体系统仿真结果满足要求。
[Abstract]:Reed is one of the most important raw materials in China's papermaking industry. The Reed production area is far from the paper making enterprise, and the increasing transportation cost has become one of the main bottlenecks of increasing the scale and benefit of the paper making enterprises in Xinjiang. The effective way to reduce the transportation cost is to pack the Reed into a high-density bag. However, the packing density of Reed is closely related to the working performance of the baler, so this paper mainly studies and analyses the key mechanism of the high density Reed baler. The main contents are as follows: (1) by analyzing the factors affecting the compression density of Reed, the closed compression method is used to carry out compression tests on three factors: feed rate, compression speed and moisture content, which affect the compression density. The results showed that the factors influencing the compression density of Reed were feed rate, compression speed and moisture content from big to small. In the experimental environment, a better compaction effect can be obtained when the feeding rate is 550 g, the compression speed is 10 mm / min, and the moisture content is 17 mm / min. The experimental results show that the feeding rate is increased in a certain range during the actual packing process. The packing density can be increased by using low horizontal compression speed and high moisture content. (2) by analyzing the functional requirements of Reed baling machine in the working process, the key mechanism-feeding compression mechanism is designed and modeled. The eccentricity of crank and crank is determined to be 130mm 273mm and 1048.5mm respectively, and the minimum transmission angle is verified to be reasonable. The kinematics and dynamics simulation analysis of feeding compression mechanism are carried out. The displacement and velocity changes of the two parts and the stress between the key parts are obtained, the time difference between the feeding action and the compression action sequence is 0.085 seconds, and the matching accuracy meets the requirements. The sweep path of the fork in the feeding mechanism and the limit position of the feed fork in XY flat and inside four outer profiles are obtained, which sweep and accumulate between 0.1m2 and 0.2m.2; at the point where the fork is fed into the highest point, the forked fork crank and the fork sleeve shaft hinge have the greatest force. Based on finite element method and Ansys software, the modal analysis of crank and connecting rod of key parts is carried out, and the natural frequencies and modes of the first 10 free modes and constrained modes of crank and connecting rod are extracted and analyzed. The results show that the position where the crank connecting rod is more likely to deform is the center of the connecting rod and the position of both sides of the center symmetry. The rigid-flexible mixing model of compression mechanism is established in Adams. The speed and force of rigid model and rigid-flexible mixed model are compared and analyzed. The results show that the velocity and force of rigid-flexible hybrid system fluctuate greatly when the system starts. The duration is about 0.05 seconds, which is basically consistent with the motion and force of the rigid system after stabilization, and the maximum difference is less than 0.5. The simulation results show that the flexibility of crank and connecting rod has little effect on the system. The simulation results of rigid body system meet the requirements.
【学位授予单位】：石河子大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB486

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