微小孔钻削关键技术研究

发布时间：2018-03-23 17:48

本文选题：微小孔　切入点：微钻削　出处：《华北理工大学》2015年硕士论文

【摘要】：微钻削是微小孔的主要加工方法,与常规孔钻削相比微小孔钻削在刀具结构、钻削机理等方面都有很大差异,微小孔钻削技术的研究成为人们广泛关注的焦点。以理论、仿真、试验相结合的研究方式对微小孔钻削的关键技术进行研究,具体内容包括:1)通过对微小孔钻削加工进行分析,得出微小孔钻削特点:刀具细小,金属切削模型需考虑刃口圆弧,存在最小切削厚度;刀具强度、刚度较差,使刀具折断成为主要破损形式;刀具的心径比大、无刃带以增加刀具强度、刚度;高速钻削下轴向力小,受刀具刚度、工件材料等影响径向钻削力不能相互抵消,成为主要钻削力,径向力也是导致刀具折断的主要因素。2)通过对小尺寸麻花钻的重要几何参数进行分析,得出螺旋角、顶角、钻心直径这三个参数通过影响刀具的前角、横刃长度、刃倾角等来间接影响刀具结构和钻削过程。通过正交仿真试验做进一步分析、优化,得到最优刀具角度为螺旋角25°、顶角120°、钻心直径0.25mm。3)对钻削参数进行分析,讨论其对钻削层厚度、钻削面积等的影响,进而讨论钻削参数对钻削力、扭矩、温度、钻头磨损破损、切屑形状、钻孔质量等因素的影响。研究表明,转速越高越有利于微小孔钻削;进给量越小,钻削力、钻削扭矩、钻削温度、磨损越小,钻孔质量越好,越有利于排屑;但进给量过小,接近最小切削厚度则会使钻削力、扭矩、温度增大,钻头磨损严重。采用特殊的建模方式对小尺寸麻花钻三维模型和微小孔钻削仿真模型进行创建,使刀具模型、钻削模型更符合实际。最后对试验结果与模拟结果进行对比,结果偏差12.06%,验证了仿真模拟在微小孔钻削研究中的有效性。
[Abstract]:Micro-drilling is the main machining method of micro-hole. Compared with conventional drilling, micro-hole drilling has great differences in cutting tool structure, drilling mechanism and so on. The research of micro-hole drilling technology has become the focus of widespread concern. The key technology of micro hole drilling is studied in combination of experiments. The specific contents include: 1) by analyzing the micro hole drilling, the characteristics of micro hole drilling are obtained: the cutting tool is small, the metal cutting model needs to consider the cutting edge arc, There is a minimum cutting thickness; the strength and stiffness of the cutting tool is poor, which makes the cutting tool fracture become the main form of breakage; the center diameter ratio of the tool is large and there is no edge band to increase the strength and stiffness of the tool; the axial force is small and the tool stiffness is affected by the cutting tool stiffness under the high speed drilling. The influence of workpiece material on radial drilling force can not be offset each other, become the main drilling force, radial force is also the main factor leading to the cutting tool break. 2) through the analysis of the important geometric parameters of small size twist drill, the helix angle and the top angle are obtained. These three parameters affect the cutting tool structure and drilling process indirectly by influencing the cutting tool's front angle, the length of the cutting edge, the angle of the edge inclination, and so on. The optimum tool angle is helix angle 25 掳, vertex angle 120 掳, drilling core diameter 0.25 mm 路3). The influence of drilling parameters on drilling layer thickness and drilling area is discussed. Furthermore, drilling parameters on drilling force, torque, temperature, bit wear and breakage are discussed. The research shows that the higher the rotational speed is, the better the drilling force, the torque, the temperature, the better the quality of drilling, the better the quality of drilling, and the better the quality of drilling. However, if the feed is too small, close to the minimum cutting thickness, the drilling force, torque and temperature will increase, and the bit wear will be serious. Finally, the experimental results are compared with the simulation results, and the deviation of the results is 12.06, which verifies the effectiveness of simulation in the research of micro-hole drilling.
【学位授予单位】：华北理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TG52

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