钻式采煤机钻头应力检测方法研究

发布时间：2018-08-18 10:48

【摘要】：煤炭资源是我国的重要资源。煤炭资源的开采主要依赖于采煤机。钻式采煤机是采煤机的一种类型,主要用于薄煤层的开采。减少采煤机的故障是采煤机安全可靠运行的前提。采煤机机械部分最常见的故障是钻头的断裂。通过应力检测可以及时发现钻头的受力情况,防止发生钻头断裂事故。目前,钻头的应力检测方法大都只能检测钻头的表面应力,但是多数的钻具断裂事故是由于内部应力过大引起的,所以寻找新的应力检测方法对钻头内部应力进行检测具有重要意义。本文将围绕采煤机钻头的漏磁应力检测技术开展研究,主要工作如下:首先,本文通过查阅相关资料,对比分析了几种常见的采煤机钻头应力检测方法,详细分析其检测机理,并给出其数学模型。在此基础上,对比这几种检测技术用于采煤机钻头应力检测的优缺点。其次,介绍了钻式采煤机的结构与工作原理,详细阐述了煤岩的主要物理特性,并建立钻头的受力数学模型。以实际案例为基础,仿真分析钻头的受力种类和受力情况。再次,简述了漏磁检测基本原理,给出了漏磁场的理论模型及基于点偶极子、线偶极子和面偶极子漏磁场分布解析表达式,分析了无限长矩形、V型和孔洞型磁偶极子的漏磁场分布特点,提出可以应用漏磁检测法对采煤机钻具进行应力检测的设想。最后,从宏观热力学理论出发,建立钻头的力磁耦合有限元数学模型。在此基础上,通过ANSYS电磁仿真软件,给出了钻头在不同应力作用下其磁场强度曲线、磁密、磁场矢量以及铁磁体内部磁感线的变化情况。通过载荷加载实验,验证了所建立的力磁耦合模型的正确性。由此验证了通过漏磁检测法,实现钻头应力检测的合理性。
[Abstract]:Coal resource is the important resource of our country. The exploitation of coal resources mainly depends on shearer. Drilling shearer is a type of shearer, which is mainly used in the mining of thin coal seam. Reducing the faults of shearer is the premise of safe and reliable operation of shearer. The most common fault in the mechanical part of the shearer is the breakage of the bit. The stress detection can detect the stress of the bit in time and prevent the bit from breaking. At present, most of the stress detection methods of drill bit can only detect the surface stress of drill bit, but most of the fracture accidents of drill tool are caused by excessive internal stress. Therefore, it is of great significance to find a new stress detection method to detect the internal stress of drill bit. The main work of this paper is as follows: firstly, through consulting relevant data, this paper compares and analyzes several common stress detection methods of shearer bit, and analyzes its detection mechanism in detail. The mathematical model is given. On this basis, the advantages and disadvantages of these detection techniques are compared. Secondly, the structure and working principle of drill shearer are introduced, the main physical characteristics of coal and rock are described in detail, and the force mathematical model of drill bit is established. On the basis of actual cases, the force type and force situation of drill bit are simulated and analyzed. Thirdly, the basic principle of magnetic leakage detection is briefly introduced, and the theoretical model of magnetic leakage field and the analytical expressions of leakage magnetic field distribution based on point dipole, line dipole and surface dipole are given. The distribution characteristics of magnetic field leakage of infinite rectangular, V-shaped and hole-type magnetic dipoles are analyzed, and the assumption that the magnetic field leakage detection method can be used to detect the stress of shearer drilling tools is put forward. Finally, based on the theory of macroscopic thermodynamics, the finite element model of force and magnetic coupling of drill bit is established. On this basis, the magnetic field intensity curve, magnetic density, magnetic field vector and magnetic inductance line of the bit under different stresses are given by ANSYS electromagnetic simulation software. The validity of the proposed model is verified by loading experiments. The rationality of bit stress detection is verified by magnetic flux leakage detection method.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD421.6

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