English Cour of
Numerical Control
数控专业英语
主讲老师：刘秀娟
基础课部大学英语教研室
教学目标考研英语二历年真题 (Teaching Target):
To make the students learn English related to their major
To improve students’ listening, speaking, reading and translation skills
上海彩妆培训学校To enlarge students’ vocabulary realted to their major（
片假名翻译
教学材料及工具 (Teaching Materials & Aids):
Text-book, tape-recorder, Materials from the internet
考核与评价方式 (Testing & Evaluating Mode):
Ask students to talk about the advantages of CNC, the heart of CNC, safety notes for CNC machine operations and so on. Then the teacher evaluates their performances.
Unit 1 Fundamentals of CNC
数控基础
SectionⅠ Talking Face to Face
At Fast Food Restaurant 在快餐馆
Fast food restaurants are popular in the United States for quick, inexpensive meals or snacks. You order your food and take it to a table yourlf. If you order your food "to go", you take it out of the restaurant. Tipping is not necessary in this kind of restaurant.
Dialogue 1:
A： What would you like to eat？
B： I'd like a hamburger with lettuce and tomato.
A： How about something to drink？
B： A Coke, plea.
A： OK. I'll e if I can get waited on.
Dialogue 2：
Ahot potato： What are you going to have？
B： I'll try a steak sandwich.
A： Can I get you anything to drink？
B： Yes, I'd like a chocolate shake.
梦工厂动画电影大全 A： That sounds good. I think I'll have the same.
SectionⅡ Being All Ears
You can think of any CNC----①------ as being nothing more than the standard type of equipment, it is replacing with a very sophisticated -----②----------added.cosplay是什么意思 Instead of activating things manually by -------③july怎么读----------and manual labor, you will be preparing a program that tells the machine what to do. Virtually anything that needs to be done on a machining center can be activated through a------④------, and anything you need the machine to do can be -------⑤--------in a program.
Section Ⅲ Maintaining a Sharp Eye
installation
Text Fundamentals of CNC
你还差得远呢What is CNC?
CNC stands for Computerized Numerical Control and has been around since the early 1970s. Prior to this, it was called NC, for Numerical Control. While people in most walks of life have never heard of this term, CNC has touched almost every form of manufacturin
g process in one way or another. If you will be working in manufacturing, it’s likely that you will be dealing with CNC on a regular basis.
The advantages of CNC
While the specific intention and application for CNC machines vary from one machine type to another, all forms of CNC have common benefits. Here are but a few of the more important benefits offered by CNC equipment.
The first benefit offered by all forms of CNC machine tools is improved automation. The operator intervention related to producing workpieces can be reduced or eliminated. Many CNC machining can run unattended during their entire machine cycle, freeing the operator to do other tasks. This gives the CNC ur veral side benefits including reduced operator fatigue, fewer mistakes caud by human error, and consistent and predictable machining time for each workpiece. Since the machine will be running under program control, the skill level required of the CNC operator (related to basic machining practice) is also reduced as compared to a machinist producing workpieces with conventi
onal machine tools.
The cond major benefit of CNC technology is consistent and accurate workpieces. Today’s CNC machines boast almost unbelievable accuracy and repeatability specifications. This means that once a program is verified, two, ten, or one thousand identical workpieces can be easily produced with precision and consistency.
A third benefit offered by most forms of CNC machine tools is flexibility. Since the machines are run from programs, running a different workpiece is almost as easy as loading a different program. Once a program has been verified and executed for one production run, it can be easily recalled the next time the workpiece is to be run. This leads to yet another benefit, fast change over. Since the machines are very easy to t up and run, and since programs can be easily loaded, they allow very short tup time. This is imperative with today’s just-in-time (JIT) product requirements.
Motion control – the heart of CNC
The most basic function of any CNC machine is automatic, preci, and consistent motion control. Rather than applying completely mechanical devices to cau motion as is required on most conventional machine tools, CNC machines allow motion control in a revolutionary manner. All forms of CNC equipment have two or more directions of motion, called axes. The axes can be precily and automatically positioned along their lengths of travel. The two most common axis types are linear (driven along a straight path) and rotary (driven along a circular path).
Instead of causing motion by turning cranks and hand wheels as is required on conventional machine tools. CNC machines allow motions to be commanded through programmed commands. Generally speaking, the motion type (rapid, linear, and circular). The axes to move, the amount of motion and the motion rate (federate ) are programmable with almost all CNC machine tools.
