centre-drilling or, pilot-hole drilling (i.e, see Fig. 50b) prior to drilling to size. Drill technol-ogy includes a range of specialised hole-making tool-ing, including: twist drills, solid drills, counter-boring and trepanning tools and deep-hole drills  . In the first instance, mention will be made of twist drilling opera-tions, then a review of these other drilling production methods will occur.Twi s t Dr i l l sTwist drilling operations have been carried out for around 150 years, with a twist drill imparting  ‘bal-anced cutting conditions’  , assuming that the drill’s geometry is symmetrical. It has been suggested that the work of drilling may be considered as two single-point lathe tools engaged in an internal straight turn-ing operation. A twist drill produces both torque and thrust as it rotates and is fed into the workpiece. The main contribution to torque is through the lips, with a small amount of torque being generated by the chisel point as the drill rotates against the resistance of the    ‘Surface Integrity’ has been coined to describe the ‘altered ma-terial zone’ (AMZ), for localised sub-surface layers that differ from those of the bulk material – considerably more will be said on this subject in Chapter 7. 0  ‘Short-hole drilling’ operations cover depth-to-hole-diam-eter-ratios of up to 6D (i.e. for diameters up to 30 mm), whilst larger drilled holes are limited to depths of 2.5D.  Where: D = nominal drill diameter.    ‘Deep-hole drilling’ and  ‘Gun-drilling’ operations are virtu-ally the same, with the term Deep-hole drilling being the pre-ferred term in this text.
钻机的发展钻孔作业也许是最流行的加工过程今天正在进行的，与他们的的起源可追溯到刀具的发展在美国北部，在第十九世纪。1864对美国内战后期，史提芬莫尔斯（即后来的设计意义的莫尔斯电码锥度的–为“套钻定位准确的为配合机床主轴）成立在莫氏麻花钻和机械有限公司。Morse接着发展可能最重要的刀具提前日期，即，无处不在的麻花钻。在图42中，今天的一些麻花钻说明的只是一个小的范围内‘实’当代设计。莫尔斯的最初设计的麻花钻过去变化很小150年–自其概念。在比较的有点粗糙，当代钻设计时间，莫尔斯说：“普通钻擦伤金属钻孔，而我切开金属和放电芯片和孔不堵塞的。莫尔斯的声明在某种程度上是最好的，乐观的，而冷酷的现实”讲述了一个不同的故事，为钻头的性能是由相当数量的因素的影响，其中大部分是在图43的上市。论文网
麻花钻的基础
一个传统的麻花钻的基本建设图44a描绘。这说明两个不同的切削区域可以成立：首先，该主切削刃，或嘴唇；然后在十字路口的间隙和主切削刃–称为横刃。事实上，麻花钻的切削过程，可以等同于一个左斜转弯工具，在耙和清除面部的几何形状这两个加工过程之间的相同和相关的已验证的实验工作在1982。这两个地区去除材料，与切削刃产生高效的材料去除，而横刃的贡献是低效的，主要负责钻井中的几何误差，加上高推力载荷。主切削刃是相对传统的芯片组负责，详见急停”照片图44B。斜切割作用发生的运动方向，是对平行于嘴唇的偏移结果径向线–提前–约为中心等于一半的钻尖的腹板厚度和增加对钻头的中心。该倾角负责在一个方向稳定的法律根据嘴唇正常诱导流屑。增加芯片流倾角可以看到图45A条，通过观察流线从芯片的产生沿唇接口和长笛的脸。这样的斜切割作用可增加捻度钻孔的有效前角的几何。随着“球直接获得三文计算–的先前描述的三角计算机软件（1982）在二文公式的切削刃性能–这些计算得到增强。在凿点，或网页，材料的去除机理是相当复杂的。近底这些凹槽在半径与凿边缘，钻头清除表面形成一个切削刀表面在本质上是高度负。为中心钻头的接近，钻头的作用类似于这一“钝楔形压头” 钻削技术英文文献和中文翻译(3):http://www.youerw.com/fanyi/lunwen_33754.html