逆向重构D型打结器运动仿真分析与打结钳嘴受力分析研究

发布时间：2018-04-19 02:17

本文选题：打结器 + 打结钳嘴　；参考：《中国农业大学》2015年硕士论文

【摘要】：秸秆作为一种重要的生物质资源,对其进行高效利用逐步成为农业和农村社会经济可持续发展的必然要求。由于秸秆存在分散、结构疏松等特点,利用方草捆压捆机进行压缩处理,是破解其高效利用过程中难以储运瓶颈的重要手段。打结器是压捆机的关键核心部件,直接影响压捆机成结效率和捆形质量。本研究以D型单结打结器(RS3770)为研究对象,利用逆向重构技术,对其进行三维几何模型重构及其重构关键面精度分析研究；基于重构打结器模型进行运动仿真研究,获取打结过程中各机构运动特性和时序关系；基于张力传感器、高速摄影以及同步技术,利用ANSYS软件平台对承载较大载荷的打结钳嘴进行了受力分析研究。具体研究结论如下： (1)通过HandySCAN700TM型手持式三维激光扫描仪获取了D型单结打结器(RS3770)所有部件的复杂曲面点云数据；基于逆向工程重构技术,借助CATIA逆向模块,对打结器所有部件进行了三维几何模型重构；对打结器重构部件的关键工作面精度进行了分析,结果发现机架轴孔、驱动齿盘内齿和内凸轮、打结钳嘴下颚、锥齿轮面90%以上区域达到了精确等级以上,所有关键工作面均能满足后期运动仿真要求。 (2)将D型打结器重构部件在Solidworks环境下装配,通过自由拖动驱动齿盘、脱绳杆、打结钳嘴、卡线轮等,发现不存在干涉现象,证明重构部件具有良好的装配效果；开展了重构D型单结打结器的卡线轮分支、打结钳嘴分支、脱绳杆分支三大传动系统的自由度分析研究,发现上述3个分支在运动时自由度均为1,驱动齿盘能保证其具有确定的运动；当卡线轮分支和打结钳嘴分支中的锥齿轮分别与驱动齿盘锁止平面接触时,其自由度均为-1,表明卡线轮分支和打结钳嘴处于静止状态；基于逆向重构打结器进行运动仿真分析研究,获得了卡线轮、打结钳嘴、上颚、脱绳杆等部件角速度-时间和角位移-时间的运动特性,其各部件运动时序规律精确解析如下：卡线轮首先旋转,0.03s后打结钳嘴开始转动,0.06s后上颚开始张开,0.11s后脱绳杆开始摆动,0.12s后卡线轮、打结钳嘴、打结钳嘴同步停止运动,0.34s秒后脱绳杆停止运动。 (3)利用华德9YFQ-1.5系列压捆机开展了秸秆捆扎试验,创制了张力传感、高速摄影以及同步控制的试验方案,首次成功获取了秸秆捆扎过程中捆绳张力数据和捆绳对打结钳嘴的作用部位；研究构建了捆绳张力与捆绳对打结钳嘴作用力转换模型,结果显示捆绳对上颚的正向压力较大,达到了314.89N；通过上述所获得的捆绳对打结钳嘴作用力大小和作用位置,利用ANSYS对上颚进行相关有限元分析,得到上颚在捆绳张力最大时刻的应力-应变图,发现上颚安装滚子轴处出现应力集中,达到了755.52MPa,进而提出了两种改进方案以减小应力集中、延长打结钳嘴使用寿命。
[Abstract]:As an important biomass resource, the efficient utilization of straw has gradually become an inevitable requirement for the sustainable development of agriculture and rural social economy.Because the straw has the characteristics of dispersion and loose structure, it is an important means to solve the bottleneck of storage and transportation in the process of high efficiency utilization by using the baler to compress the straw.Knitting machine is the key component of the baler, which directly affects the binding efficiency and the quality of bundles.In this study, the D type single knot knotting machine RS3770 is used as the research object, the 3D geometric model reconstruction and its key surface precision analysis are studied by using reverse reconstruction technology, and the kinematics simulation research based on the reconstructed knotting device model is carried out.Based on the tension sensor, high-speed photography and synchronization technology, the force analysis of the knots loaded with a large load was carried out by using ANSYS software platform.The specific findings of the study are as follows:HandySCAN700TM handheld 3D laser scanner is used to obtain the point cloud data of complex curved surface of all components of D type single knot knotter RS3770. Based on reverse engineering reconstruction technology, CATIA reverse module is used.The 3D geometric model reconstruction of all the parts of the knotter is carried out, and the precision of the key working face of the reconstructed part of the knotting apparatus is analyzed. The results show that the shaft hole of the rack drives the inner teeth and inner cam of the tooth disk, and the jaw of the knotted pliers.More than 90% of the bevel gear face has reached the accuracy level, and all the key working faces can meet the requirements of the later stage motion simulation.(2) assembling the reconstruction parts of D type knots in the Solidworks environment, by freely driving the tooth disc, the detaching rod, the knotting pliers, the clamping wheels, etc., it is found that there is no interference phenomenon, and it is proved that the reconstructed parts have good assembly effect.The degrees of freedom of three transmission systems, namely, clamping wheel branch, knotting clamp branch, and detaching rod branch, are analyzed and studied in this paper.It is found that the above three branches have a degree of freedom of 1 when moving, and the drive disk can guarantee its definite motion, and when the bevel gears in the branch of the clamping wheel and the clamping clamping mouth are in contact with the locking plane of the drive disk,The degree of freedom is -1, which indicates that the clamping wheel branch and the knotted tongs are in a static state, and the kinematic simulation analysis based on the reverse reconfiguration knotting device is carried out, and the clamping wheel, knot tongs and jaws are obtained.The kinematic characteristics of angular velocities, angular displacements and time of detaching rod and other components,The timing rules of motion of each component are as follows: the clamping wheel first rotates 0.03s, then the knotted tongs start to rotate 0.06s, then the upper jaw starts to open 0.11s, then the detaching rod begins to swing 0.12s after the clamping wheel, and the knotted pliers,The knotted tongs stop synchronously for 0.34 seconds and then the rope rod stops moving.(3) the strapping test was carried out with Ward 9YFQ-1.5 series strapping machine, and the test scheme of tension sensing, high speed photography and synchronous control was developed.For the first time, the data of rope tension in strapping process and the action position of tie rope on knots were obtained successfully, and the model of the force conversion between cord tension and tie rope on knot tongs was constructed. The results showed that the forward pressure of tie rope on jaw was high.Through the above obtained force and position of the binding rope to the knotted forceps, the relative finite element analysis of the upper jaw is carried out by using ANSYS, and the stress-strain diagram of the upper jaw at the maximum tension of the cord is obtained.It is found that the stress concentration appears at the axis of the jaw roller, reaching 755.52 MPa, and two improved schemes are proposed to reduce the stress concentration and prolong the service life of the knotted tongs.
【学位授予单位】：中国农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S817.11

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