磨机换衬板专用机械手的拓扑优化设计

发布时间：2018-03-28 23:15

本文选题：磨机换衬板专用机械手　切入点：拓扑优化　出处：《江西理工大学》2017年硕士论文

【摘要】：对于整个磨机系统而言,衬板是数量最大的零部件之一,也是受磨损破坏量最多的零部件之一。传统采用人工的方式更换衬板耗时长,工人的劳动强度也大且还存在安全隐患,这严重影响磨机的作业效率。因此,研制出性能稳定、工作可靠的磨机换衬板专用机械手对解决矿山磨机衬板更换问题,将产生重大意义。本文以某矿山选矿厂筒体直径为4.8m的球磨机为对象,针对初期设计的磨机换衬板专用机械手挠度过大的问题,采用连续体拓扑优化的方法对其进行拓扑优化设计,得到的磨机换衬板专用机械新手结构,并通过仿真分析进行验证。全文主要进行了以下研究工作。(1)分析磨机换衬板专用机械手的原理及组成,设计其运动系统的主要技术参数与最大负载下四个不同工况。对比分析各工况,并针对其中三个相对较危险工况做了结构静力分析,以确定危险工况。同时,为确定对整机挠度变形影响较大的零部件,对主要组成部件吊臂与爪具体也进行了具体的挠度变形分析。结果表明:安装离机械手最远且俯仰角最小位置的衬板时对应的工况3的应力与变形都是最大的,即确定工况3为危险工况;危险工况下,整机最大变形量为7.713mm,即挠度变形过大、刚度不足;且吊臂与爪具体单部件独的变形量都大,则知它们对整机的挠度变形影响度很大。由此得到的结论为后文磨机换衬板专用机械手拓扑优化设计指明了方向。(2)在Hyperworks软件的优化模块Optistruct中,基于SIMP方法的拓扑优化模型,以体积分数为约束、最小柔度为目标的方法,对磨机换衬板专用机械手的吊臂与爪具体分别做了拓扑优化设计,得到新结构。最后针对危险工况做了整机的刚度验证。结果表明:经拓扑优化设计后,整机的挠度变形减小到4.228mm,且应力仍小于材料许用应力值,机械手准确抓取并对位安装衬板的可靠性得到提高。(3)针对危险工况,对拓扑优化后的磨机换衬板专用机械手做模态分析与瞬态分析,并与优化前的分析结果作对比;同时在Solidworks Motion插件中做工作过程运动仿真。结果显示:拓扑优化后的磨机换衬板专用机械手的前两阶固有频率得到提高,更好地避免低频干扰共振的发生;在瞬态冲击载荷作用下,优化前的整机在1.6s后达到稳定状态,而优化后仅在0.8s后就达到了稳定状态,时间明显缩短,整机的稳定性更好;运动仿真过程中位移、速度及加速度曲线均是光滑的,不产生零部件间的干涉碰撞,即拓扑优化设计的整机在运动性能方面结构合理。
[Abstract]:For the whole mill system, the liner is one of the largest parts, and also one of the most damaged parts. The traditional manual method to replace the liner takes a long time, the labor intensity of workers is also large and there are hidden dangers of safety. This has seriously affected the working efficiency of the mill. Therefore, a special manipulator, which has stable performance and reliable work, has been developed to solve the problem of replacing the lining plate of the mine mill. This paper takes the ball mill with the diameter of 4.8 m in a mine concentrator as the object, aiming at the problem of excessive deflection of the special manipulator designed in the initial stage for changing the lining plate of the mill. The topology optimization method is used to optimize the topology of the mill, and the new mechanical structure is obtained. The main work of this paper is as follows: 1) analyzing the principle and composition of the special manipulator for the mill lining plate. The main technical parameters of the motion system are designed and four different working conditions under the maximum load are designed. Each condition is compared and analyzed, and structural static analysis is made for three relatively dangerous working conditions in order to determine the dangerous working conditions. In order to determine the parts which have great influence on the deflection of the whole machine, The deflection analysis of the main components of the boom and claw is also carried out. The results show that the stress and deformation of the working condition 3 are maximum when installing the liner which is the farthest away from the manipulator and with the smallest pitch angle. The maximum deformation of the whole machine is 7.713mm, that is, the deflection is too large and the stiffness is insufficient. It is known that they have great influence on the deflection and deformation of the whole machine. The conclusion indicates the direction of topology optimization design of the special manipulator for the mill lining plate.) in the optimization module Optistruct of Hyperworks software, the topology optimization model based on SIMP method is proposed. Taking volume fraction as constraint and minimum flexibility as objective method, the specific topology optimization design of boom and claw of special manipulator for changing lining plate of grinding machine is made. The new structure is obtained. Finally, the stiffness of the whole machine is verified according to the dangerous conditions. The results show that the deflection of the whole machine is reduced to 4.228 mm after topology optimization, and the stress is still less than the allowable stress of the material. According to the dangerous condition, the modal analysis and transient analysis of the special manipulator after topology optimization are done, and the results are compared with the results before optimization. At the same time, the simulation of the working process in the Solidworks Motion plug-in is done. The results show that the first two natural frequencies of the special manipulator for changing linings of the mill are improved after topology optimization, and the low frequency interference resonance is better avoided; Under the action of transient impact load, the whole machine before optimization reaches the stable state after 1.6 seconds, but only reaches the stable state after 0.8 seconds after optimization, the time is obviously shortened, and the stability of the whole machine is better. The velocity and acceleration curves are smooth, and there is no interference collision between parts, that is, the structure of the whole machine designed by topology optimization is reasonable in terms of motion performance.
【学位授予单位】：江西理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD453;TP241

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