数控专业英语-.doc

课程教案
授课时间
第 14周 第 1､2节课 2009 年 5 月 18日
课次
14
授课方式
(请打√)
理论课(√) 讨论课( ) 实践课( )
习题课( ) 其 他( )
课时安排

授课题目(教学章､节或主题):3.4.1 NC Electric Discharge Shaped Machine
3.4.2 NC WEDM Machine
教学目的､要求(分掌握､熟悉､了解三个层次):
目的:掌握特种加工中的电火花加工与线切割的工作原理及英文表达
要求:理解电火花加工与线切割的机床组成及英文表达
教学内容重点及难点:
重点:电火花加工与线切割的工作原理
难点:电火花加工与线切割的工作原理
教 具

作业
思考题

课后小结

教 学 基 本 内 容
方法及手段
一:New words and phrases
u discharge v.放电
u spark n.火花
u erode v.腐蚀,磨损
u erosion n.腐蚀,磨损
u roughness n.粗糙度
u electrode n.电极
u density n.密度
u gasify v.汽化
u minute adj.微小的

理论讲授
教 学 基 本 内 容
方法及手段
u corrode v.蚀,蚀除
u melt v.熔化
u scatter v.散布
replicate v.复制
reciprocate v.往复,互换
rigidity n.刚性
pulley n.滑轮,滑车
gang n.一组,一群
insulation n.绝缘
flush v.清洗
二､content
Electrical discharge machining (EDM), or spark machining, as it is so called, is based on the eroding effect of an electric spark on both the electrodes used to produce.The advantage is that electrical discharge machining processes with good surface roughness and machines metal of any hardness.
放电加工或称为电火花加工,是基于两电极之间产生的电火花的腐蚀作用实现的｡电火花加工的主要优点是可获得较低的表面粗糙度,并且可以加工任何硬度的金属｡
u Impulse power is linked to the tool electrode and the workpiece. Using automatic feed adjustment device makes the tool electrode and the workpiece all along keep a small discharge gap. By the action of impulse electric current, spark discharging is produced. The constant impulse discharge will replicate the tool shape of the tool electrode on the workpiece and carry out the shaped machining.
在工具电极与工件之间连接脉冲电源,利用自动进给调节装置使工具电极与工件始终保持一个很小的放电间隙｡在脉冲电流的作用下,产生火花放电｡不断的脉冲放电,就可将工具电极的形状复制在工件上实现成型加工｡
u NC electric discharge shaped machining machine is composed of machine itself, impulse power, automatic feed adjustment device,NC system, working liquid cycle system and so on.
数控电火花成型加工机床由机床本体､脉冲电源､自动进给调节装置､数控系统､工作液循环系统等组成｡

教 学 基 本 内 容
方法及手段
u The basic principal of WEDM is that the continuously moving thin metal wire is taken as tool electrode and the pulsating current is linked to the metal wire and the workpiece, and then with the impulse spark discharging between the metal wire and the workpiece, the metal is made to be melted or to be gasified.During the relative movement of the electrode wire and workpiece, the workpiece is cut and shaped.WEDM is also called wire cut.
电火花线切割的基本原理是利用连续移动的细金属丝作为工作电极,并在金属丝与工件之间通以脉冲电流,利用它们之间的脉冲火花放电效应,使金属熔化或汽化,并通过电极丝与工件的相对运动,对工件进行切割成型｡电火花切割也简称为线切割｡
u (1) WEDM\|HS .The electrode wire of this kind of machine tool carries out high-speed and reciprocating movement.So it is also called reciprocating or rapid wire cutting machine.､高速走丝线切割机床,这类机床的电极丝做高速往复运动,也称为往复走丝或快走丝线切割机｡
u (2) WEDM-LS .The electrode wire of this kind of machine tool carries out low-speed and single movement.So it is also called single or slow wire cutting machine.
低速走丝线切割机床,这类机床的电极丝做低速单向运动,故也称为单向走丝或慢走丝切割机｡

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注:课程教案按授课次数填写,每次授课均应填写一份;重复班授课可不另填写教案｡
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