钻削工况在线监测研究

发布时间：2018-12-10 14:41

【摘要】：目前针对摇臂钻、组合机床、专用机床的钻削动力头研究就多,但应用于动平衡机的钻削动力头和钻削工况的在线监测研究较少,动平衡机的钻削深度控制关键在于确定工件与钻头接触点,本文在自行设计的钻削动力头的基础上,实现了对轴向力和电机电流的在线监测,分析了影响钻头耐用度的因素和钻头磨损的在线监测的方法,对钻削工况的在线监测进行了研究,对提高动平衡机去重精度和自动化程度有很大帮助,具有重要的研究价值和意义。本文介绍了钻削工况发展概况和国内外研究现状,并围绕着以下几个方面展开本课题的研究工作:首先,介绍了钻削动力头的机械结构。对自动钻削系统系统的工作原理进行了描述,确定了测力盘的最佳贴片位置,并对钻削动力头和主轴的动态特性进行了有限元分析。其次,轴向力和电机电流的在线检测及钻削深度控制。分析了轴向力和电机电流分别与进给速度和主轴转速的关系公式。通过对测力盘的应变敏感梁变形的检测得到轴向力的变化曲线,通过霍尔电流传感器对电机电流进行实时监测,根据得到的轴向力和主轴电流的变化曲线进行曲线拟合判断钻头与工件接触初始点,通过DSP控制发出脉冲信号达到需要的钻削深度。然后,对钻头耐用度的影响进行了研究。分析了钻头磨损破坏的主要形式及应对办法,理论推导出钻头耐用度与切削用量之间的关系公式,用线性回归法对泰勒公式中参数的确定分析。建立切削温度与轴向力等变量之间的关系,刀具寿命与轴向力和转矩之间的关系。最后,钻头耐用度实验验证。选定钻削用量的前提下,对理论刀具寿命和现场刀具寿命的比较与分析。
[Abstract]:At present, there are many researches on drilling power head for rocker arm drill, combination machine tool and special machine tool, but there are few on-line monitoring researches on drilling power head and drilling condition applied to dynamic balancing machine. The key of drilling depth control of dynamic balancing machine is to determine the contact point between workpiece and bit. Based on the self-designed drilling power head, the on-line monitoring of axial force and motor current is realized in this paper. The factors affecting bit durability and the on-line monitoring method of bit wear are analyzed. The on-line monitoring of drilling condition is studied, which is of great help to improve the weight removal accuracy and automation degree of dynamic balancing machine. It has important research value and significance. This paper introduces the development of drilling conditions and the present research situation at home and abroad, and carries out the research work around the following aspects: firstly, the mechanical structure of drilling power head is introduced. The working principle of the automatic drilling system is described, the optimum placement of the force measuring plate is determined, and the dynamic characteristics of the drilling power head and spindle are analyzed by finite element method. Secondly, the axial force and motor current on-line detection and drilling depth control. The relations between axial force and motor current with feed speed and spindle speed are analyzed. The change curve of axial force is obtained by measuring the strain sensitive beam deformation of the force measuring plate, and the motor current is monitored in real time by Hall current sensor. According to the curves of axial force and spindle current, the initial contact point between bit and workpiece is estimated by curve fitting, and the required drilling depth is obtained by DSP control. Then, the influence of bit durability is studied. The main forms and countermeasures of bit wear failure are analyzed, the relationship between bit durability and cutting parameters is derived theoretically, and the determination of parameters in Taylor formula is analyzed by linear regression method. The relationship between cutting temperature and axial force and the relationship between tool life and axial force and torque are established. Finally, the bit durability is verified by experiments. The theoretical tool life and field tool life are compared and analyzed on the premise of selecting drilling dosage.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG52

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