WK-75矿用挖掘机前端工作机构刚柔耦合性能研究及优化

发布时间：2018-03-20 05:00

本文选题：矿用挖掘机　切入点：前端工作机构　出处：《太原理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：机械式挖掘机在露天煤矿开采生产活动中发挥着不可替代的作用,具有高产、高效、高耗等特点。西部地区近年不断有大型煤矿投入生产,其中不乏大型露天煤矿,机械式挖掘机需求连年增长。优异的挖掘机性能不仅能提高挖掘效率,提高机器使用寿命,也反映了国家重型机械制造的实力。在挖掘过程中,挖掘机的前端工作机构的性能优劣对整机的工作效果有着直接影响,因此有必要对前端工作机构的性能进行深入研究。课题获得国家高技术研究发展计划(863计划)项目“75m3大型露天矿用挖掘机研制”(NO.2012AA062001)的资助。本文以太原重工自主研发的WK-75系列大型矿用挖掘机前端工作机构为研究对象,主要研究内容如下:首先深入探讨机械式挖掘机挖掘轨迹数学模型,分析了对数螺旋线轨迹的理论推导过程不完善之处,并采用机构运动学方法对斗杆的运动进行分解与合成,进而推导出随推压提升速度变化的挖掘轨迹数学模型。其次,依托机构运动学挖掘轨迹,构建了挖掘后角、提升钢丝绳与斗杆中心线夹角、挖掘体积、初始投放角、出料角、最大切削厚度、挖掘阻力等数学模型,并采用ADAMS/Cable模块建立钢丝绳,进而完成挖掘机数字化样机。仿真后,测量推压轴中心到铲斗与提梁铰孔间距离等各参数,分析了切削后角和提升钢丝绳与斗杆中心线夹角在挖掘过程的变化规律。对比研究了虚拟样机仿真、机构运动学、对数螺旋线三组的挖掘轨迹。再次,在Patran中生成起重臂和斗杆的模态中性文件,并导入ADAMS中的挖掘机多刚体模型。采用这种刚柔耦合方法,建立了WK-75刚-柔耦合虚拟样机模型。仿真分析对比了多刚体系统和刚柔耦合系统中运动参数的差异。对起重臂和斗杆在挖掘过程中的三种工况下的应力变化情况进行了深入研究,获得了挖掘过程中的应力变化规律,可以为后续疲劳分析提供合理动态应力谱。最后,选取提升速度、推压速度、挖掘位置参数为设计变量,结构尺寸和挖掘体积为约束,选取挖掘后角变化最小、提升钢丝绳与斗杆中心线夹角最大和挖掘体积最大为目标函数,采用非线性二次规划Pointer算法,Isight与Matlab联合仿真进行优化设计,并将优化前后的参数进行分析比较检验优化效果。
[Abstract]:Mechanical excavators play an irreplaceable role in open-pit coal mining, and have the characteristics of high yield, high efficiency and high consumption. In recent years, large coal mines have been put into production in the western region, among which there are many large open pit coal mines. The demand for mechanical excavators has been increasing year after year. Excellent excavator performance can not only improve the efficiency and service life of the machine, but also reflect the strength of the national heavy machinery manufacturing. The performance of the front-end working mechanism of the excavator has a direct impact on the working effect of the whole machine. Therefore, it is necessary to conduct in-depth research on the performance of front-end working mechanism. The project is supported by the National High Technology Research and Development Program (NRDP) "75m3 large open-pit excavator development" (no. 2012AA062001). This paper is based on Taiyuan heavy Industry Autonomous Research. The front-end working mechanism of WK-75 series large-scale mining excavator is the object of study. The main research contents are as follows: firstly, the mathematical model of excavating trajectory of mechanical excavator is deeply discussed, and the imperfections in the theoretical derivation of logarithmic spiral trajectory are analyzed, and the kinematics method of mechanism is used to decompose and synthesize the motion of bucket rod. Then, the mathematical model of mining track is derived, which changes with the speed of pushing and lifting. Secondly, based on the kinematics track of the mechanism, the mining rear angle, the angle between the hoisting wire rope and the central line of the bucket rod, the excavating volume, the initial drop angle and the discharging angle are constructed. The maximum cutting thickness, digging resistance and other mathematical models are used to establish the wire rope with ADAMS/Cable module, and then the digitized prototype of the excavator is completed. After simulation, the distance between the center of the pushing shaft and the bucket and the hinge of the lifting beam is measured. In this paper, the variation law of the angle between the cutting back angle and the angle between the hoisting wire rope and the central line of the bucket rod in the mining process is analyzed. Three groups of mining tracks of virtual prototype simulation, kinematics of mechanism and logarithmic spiral line are compared and studied. The modal neutral files of lifting arm and bucket rod are generated in Patran, and the multi-rigid body model of excavator in ADAMS is introduced. The rigid-flexible coupling method is used. The WK-75 rigid-flexible coupling virtual prototyping model is established. The differences of motion parameters between multi-rigid body system and rigid-flexible coupling system are analyzed and compared by simulation. The stress changes of lifting arm and bucket rod under three conditions during excavation are analyzed and compared. A thorough study was carried out. The law of stress variation in mining process is obtained, which can provide a reasonable dynamic stress spectrum for subsequent fatigue analysis. Finally, the lifting speed, pushing speed, mining position parameter are selected as design variables, structure size and excavation volume as constraints. The minimum change of the rear angle, the maximum angle between the hoisting wire rope and the central line of the bucket rod, and the maximum volume of the excavating are selected as the objective functions, and the nonlinear quadratic programming (Pointer) algorithm is used to optimize the design by using the Pointer algorithm of nonlinear quadratic programming and the joint simulation of Matlab and Isight. The parameters before and after optimization are analyzed and compared to verify the optimization effect.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TD422.2

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