Post on 18-Jan-2016
Unit FourUnit Four
Passage Two
Machining Centers
Learning Targets
• To understand the whole passage
• To know how to express types of machining centers and parts of the CNC Machining Center in English
• Step A: Lead in • Step B: Passage Understanding• Step C: Structural Analyzing • Step D: Assignment
Teaching Procedures
Do you know?
1.What are the types of machining centers?
2. What are the parts of CNC Machining Center ?
You can find the answer after fast reading.
Passage Understanding
Passage Understanding
Types of machining centers
卧式加工中心
horizontal spindle type
Passage Understanding
立式加工中心
Types of machining centers
vertical spindle type
Passage Understanding
Parts of the CNC Machining Center
bed
saddle
column
table
床身
溜板
立柱
工作台
Passage Understanding
servo system
spindle
tool changers
MCU
Parts of the CNC Machining Center
伺服系统
主轴
刀具交换装置
机床控制单元
Passage Understanding托盘
梭子
滑鞍
导轨
参数
pallet
shuttle
saddle
bedway
specification
Sentences StructureThe vertical spindle machining center is a saddle-type construction with sliding bedways which utilizes a sliding vertical head instead of a spindle movement.主句的表语后面有较长的后置定语，在翻译时把 with sliding bedways 转换成前置定语，而把定语从句作为一个单句来处理。
立式加工中心是一种带有滑动床身导轨的溜板型结构，它是利用垂直方向的床头的滑动来代替主轴的移动。
Sentences StructureThe bed is usually made of high-quality cast iron which provides a rigid machine capability of performing heavy-duty machining and maintaining high precision.
这一句比较长，在翻译时应转化为两个短句。定语从句中 ,provides 的宾语是 capability 。床身通常由优质铸铁制成 ,铸铁为刚性机床提供了执行重载加工任务和保持高精度加工的能力。
Sentences StructureThe servo system, which consists of servo drive motors, ball screws, and position feedback encoders, provides fast, accurate movement and positioning of the XYZ axis slides.主语： the servo system 谓语： provides
定语从句： which consists of servo drive motors, ball screws, and position feedback encoders伺服系统包括伺服电机、滚珠丝杠和位置反馈编码器，它提供快速而准确的 XYZ 轴的移动和定位。
Sentences StructureTool changers are usually bidirectional, which allows for the shortest travel distance to randomly access a tool.
which 指代的是前面整个句子。做这种用法时， which 可以替换成 as.
刀具交换装置通常是双向的，这样就允许以最短的路径任意地存取刀具。
Structural Analyzing
Part one: para1- 4
Part two: para 5- 13
Part three: para 14
Types of machining centers
Parts of the CNC machining center
Machine axes
ExercisesPut the following into Chinese and Put the following into Chinese and recite them.recite them.NC: numerical control
NC machine tools
计算机数控CNC: computerized numerical control
数字控制
MCU: machine control unit
机床控制单元
数控机床
ExercisesPut the following into Chinese and Put the following into Chinese and recite them.recite them.
a DC motor
incremental positioning
步进电机a stepper motor
直流电机
absolute positioning 绝对定位
相对定位
ExercisesTry to identify the subject, predicate, object Try to identify the subject, predicate, object and attribute of the following sentences and to and attribute of the following sentences and to underline them separately.underline them separately.
1. The bed is usually made of high-quality cast iron which provides a rigid machine capability of performing heavy-duty machining and machining high precision.
The bed is usually made of high-quality cast iron which provides a rigid machine capability of performing heavy-duty machining and machining high precision.
ExercisesTry to identify the subject, predicate, object Try to identify the subject, predicate, object and attribute of the following sentences and to and attribute of the following sentences and to underline them separately.underline them separately.
2. New MCUs are becoming more sophisticated, making machine tools more reliable and the entire machining operations less dependent on human skills.
New MCUs are becoming more sophisticated, making machine tools more reliable and the entire machining operations less dependent on human skills.
AssignmentAnswer the following questions Answer the following questions according to the text.according to the text.
1. What are the types of machining centers?
2. What are the parts of CNC Machining Center?
3. What is the five-axis machining center?