? 有时所加工的光滑直孔的直径太大或者不是标准系列尺寸，无法匹配钻头或铰刀时，就需要进行镗孔加工。
? 为了使镗孔加工精度高，装夹必须刚性好，机床必须牢固，而且必须采用自动进给。
幻灯片65
5.4 Drilling and Drill Press
? Types of drill press ? Sensitive bench type ? Upright type ? Radial type ? Special purpose type
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5.4 Drilling and Drill Press
Construction Features of Sensitive Drilling Machine Base Column Chuck
Head
Quill assembly
Table Head Quill Assembly Chuck Column Table Base 幻灯片67
Construction Features of Sensitive Drilling Machine Base It is heavy gray iron or ductile iron casting with slots to support and hold work that is too large for the table. Column The outer surface is machined to function as a precision way of aligning the spindle with table. Chuck Chuck is used to clamp and fix the drill through a cone surface locking mechanism. Table Most worktables have slots and holes for mounting vises and other workholding accessories. Head Speeds on a stepped V pulley drive are changed by changing the position of the V-belt. Speeds on a variable-speed drive mechanism are changed by a hand wheel on the head. Quill Assembly The quill moves vertically by means of a rack and pinion. Located on the lower end of the spindle is either a Morse taped hole or a threaded stub where the drill chuck is mounted. 解决各种难切削材料的加工问题
工业现 代化对 机械制 造业提 出的新 要求 解决各种复杂表面的加工问题
解决各种超精、光整或具有特殊要求的零件的加工问题 解决各种特殊材料、特殊零件的加工问题
上述工艺问题依靠传统切削已无法加工，特种加工在这种环境和条件下即应运而生。 幻灯片4
Unit6 Nontraditional Machining Processes What is main difference between traditional machining and Nontraditional Machining Processes? 幻灯片5
Unit6 Nontraditional Machining Processes ? 6.1 Introduction
……Non-traditional machining processes are defined as a group of processes that remove excess material by various techniques involving mechanical,
thermal,
electrical
or
chemical
energy
or
combinations of these energies but do not a sharp cutting tool as it is used in traditional manufacturing processes. thermal ['θ?:m?l] adj. 热的、热量的
特种加工是指这样一组加工工艺，它们通过各种涉及机械能、热能、电能、化学能或者以上能量的组合形式的技术而不使用传统加工所需的锐利刀具来去除工件的多余材料。 幻灯片6
Unit6 Nontraditional Machining Processes
? 6.1 Introduction
……Traditional machining also results in tool wear and loss of quality in the product owing to induced residual stresses during machining. owing to 由于
residual stresses 残余应力
由于在加工过程中会产生残余应力，传统加工会造成刀具磨损以及损坏产品质量。 幻灯片7
Unit6 Nontraditional Machining Processes ? 6.2 Electrical Discharge Machining (EDM) ? 知识背景（ Background ）：
电火花加工是在特定介质中，通过工具电极和工件电极之间脉冲放电时的电腐蚀作用，对工件进行加工的一种方法，可以加工各种高熔点、高硬度、高强度、高纯度、高韧性材料，广泛用于模具制造中。