旋挖钻机工作机构的优化与力学特性分析

发布时间：2018-07-26 18:23

【摘要】：旋挖钻机由于其施工方便,环保的特点,近几年来迅速的在国内外道路、桥梁、铁路等方面得到了广泛的应用。而且随着当前工程难度的增加,要求入岩桩基础较多,因此对旋挖钻机工作机构的要求越来越高。本文通过工程施工和理论研究相结合,通过分析旋挖钻机钻进岩层的效率,从源头得出极限工况下主机需要提供的各项能力指标,据此建立力学模型,通过计算得出作用于平行四边形机构上的力,通过尺寸、力的约束采用遗传算法对平行四边形机构建立模型进行优化,使其工作机构优化得到了较为理想的结果。结合工业性试验中出现断轴的实际情况,找出了出现断轴问题的根本原因。具体研究内容如下:(1)通过类比分析,对旋挖钻机的破岩机理进行了详细的阐述,引入岩石切削过程中贯入度的概念,建立岩石切削的理论模型,对实际机型的钻进效率进行了计算,从源头得出极限工况下主机需要提供的扭矩和加压力。通过对施工现场的统计数据分析,验证了该模型的正确性。(2)利用上述计算的结果,通过列举所有工况,对不同工况进行受力分析,找出最危险的工况,为后期进行危险工况校核提供数据支持。通过对两种限位工况的分析,找出了旋挖钻机断轴的主要原因,提出了相应的保护措施。(3)考虑变幅机构的特点,抽象变幅机构优化的设计变量,建立了以油缸安装距和长度最短,油缸动作的压力角最小,整机结构尺寸最小,变幅上下前后动作范围最大为目标的多目标优化模型。在其机构相互约束条件下,确立了其对应的约束函数,通过多目标优化中常见的权重系数法,成功的将多目标的优化转换为单目标函数的优化方法。(4)为提高计算效率,采用了具有全局搜索功能的遗传算法对机构优化的多目标函数进行计算,得到了不同权重系数下的优化结果。通过将优化结果和实际机型进行对比,两者数据接近,说明了该优化模型的正确性与可行性。(5)结合多目标优化模型的计算结果,设计了相应的变幅机构(动臂、支撑杆、连接体部件)等,通过有限元方法,计算构件的应力应变,找到最大应力点和应力集中位置,有效优化应力集中位置,形成最终需要的设计模型。
[Abstract]:Rotary drilling rig has been widely used in road, bridge, railway and so on in recent years because of its convenient construction and environmental protection. With the increasing of engineering difficulty, the foundation of pile is required more and more, so the working mechanism of rotary drilling rig is required more and more. Through the combination of engineering construction and theoretical research, this paper analyzes the efficiency of drilling with rotary drilling rig, and obtains from the source all kinds of capability indexes that the main engine needs to provide under the limit working conditions. Based on this, the mechanical model is established. The force acting on the parallelogram mechanism is calculated. The genetic algorithm is used to optimize the model of the parallelogram mechanism through the size and force constraints, and the optimal results are obtained. Combined with the actual situation of broken shaft in industrial test, the root cause of the problem of broken shaft is found out. The specific research contents are as follows: (1) through analogy analysis, the rock breaking mechanism of rotary drilling rig is expounded in detail, the concept of penetration in rock cutting is introduced, and the theoretical model of rock cutting is established. The drilling efficiency of the actual engine is calculated, and the torque and pressure required by the main engine under the limited working conditions are obtained from the source. The correctness of the model is verified by analyzing the statistical data of the construction site. (2) by enumerating all the working conditions, the most dangerous working conditions are found out. To provide data support for the later stage of dangerous condition check. Based on the analysis of two limiting working conditions, the main reasons of shaft breakage of rotary drilling rig are found out, and the corresponding protection measures are put forward. (3) considering the characteristics of amplitude change mechanism, the design variables of abstract amplitude change mechanism optimization are considered. A multi-objective optimization model with the shortest installation distance and length of the cylinder, the smallest pressure angle of the cylinder action, the smallest structure size of the whole machine, and the maximum range of the upper and lower movements of the oil cylinder are established. Under the constraint condition of the mechanism, the corresponding constraint function is established. Through the weight coefficient method, the multi-objective optimization is successfully converted into the single-objective optimization method. (4) in order to improve the computational efficiency, The genetic algorithm with global searching function is used to calculate the multi-objective function of mechanism optimization, and the optimization results under different weight coefficients are obtained. By comparing the optimization results with the actual models, the two data are close to each other, which shows the correctness and feasibility of the optimization model. (5) combined with the calculation results of the multi-objective optimization model, the corresponding amplitude-changing mechanism (arm, support rod) is designed. Through the finite element method, the stress and strain of the member are calculated, the maximum stress point and the stress concentration position are found, the stress concentration position is effectively optimized, and the final design model is formed.
【学位授予单位】：石家庄铁道大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU67

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