毕业论文-复杂零件加工工艺设计及数控编制(完稿)

==========机电工程学院机电一体化专业毕业论文复杂零件加工工艺设计及数控编制

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专业：机电一体化

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完成时间：2012年4月

数字控制（number control）简称数控（NC），是近代发展起来的一种自动控制技术，是用数字化信息实现机械设备控制的一种方法。

随着科学技术的不断发展，社会对产品多样化的要求日益强烈，产品更新换代悦来越快，多品种、中小批量生产的比重明显增加，复杂形状的零件越来越多，精度要求也越来越高。此外，激烈的市场竞争要求产品研制生产周期越来越短，传统的加工设备和制造方法已难于适应这种多样化、柔性化与复杂形状零件的高效，高质量加工要求。因此，近几十年来，能有效解决复杂、精密、小批多变零件加工问题的数控加工技术得到了迅速发展和广泛应用，使制造技术发生了根本性的变化。

关键词：数控技术核心；数控装备；高精尖

Digital Control (number control) referred to as NC (NC), developed a kind of modern automation technology is the use of digital information to achieve a method of control of machinery and equipment.

With the continuous development of science and technology, the community has increasingly stronger demands for product diversification, product upgrading Panda faster, multi-species, a marked increase in the proportion of small and medium volume production, complex-shaped parts, more and more the more precision to the higher. In addition, the intense competition in the market demands shorter and shorter product development cycle, the traditional processing equipment and manufacturing methods are difficult to adapt to this diversity, flexible high-performance parts with complex shapes, high-quality processing requirements. Thus, in recent decades, can effectively solve the complex, sophisticated, small batch processing problems and ever-changing parts CNC machining technology has been rapid development and wide application of

Manufacturing technology to make fundamental changes have taken place.

Key words: numerical control technology

引言 (5)

1.概论 (6)

1.1 数控加工技术概况 (6)

1.2 数控技术的特点 (6)

1.3 数控机床的加工原理 (6)

1.4 数控加工技术的主要应用对象 (7)

1.5 数控技术的发展趋势 (7)

2．数控加工工艺 (7)

2.1 数控加工工艺概述 (7)

2.1.1 数控加工工艺的特点 (8)

2.1.2 数控加工工艺的主要能容 (8)

2.1.3 数控机床的合理选用 (8)

2.2 控加工工艺分析与工艺设计 (8)

2.2.1 控加工工艺分析 (8)

2.2.2 数控加工工艺设计 (8)

3．数控编程基础 (8)

3.1 程序格式 (9)

3.1.1 程序段的格式和组成 (9)

3.1.2 程序号 (9)

3.1.3 坐标字的表示方式 (9)

3.2 数控程序的指令代码 (9)

4．数控车床实例应用 (10)

4.1 工艺方案订制 (10)

4.2 程序设计 (11)

结束语 (12)

谢辞 (14)

参考文献 (15)

数字控制简称数控，是近代发展起来的一种自动控制技术，是用数字化信息实现机械设备控制的一种方法。1952年美国研制出世界上第一台数控铣床，开创了世界数控机床发展的先河。随后，德国、日本、苏联等国于1956年分别研制出本国第一台数控机床。我国于1958年由清华大学和北京第一机床厂合作研制出我国第一台数控铣床。近年来，由于引进了外国色数控系统与伺服系统的制造技术，使我国数控机床在品种、数量、和质量方面得到了迅速发展，缩短了与国外厂家的差距。在“九五”末期，国产数控机床的国内市场占有率达50%，配国产数控系统也达到了10%，2001年国内数控金属切削机床产量已达1.8万台。

1.概论

1.1 数控加工技术概况

随着科学技术的不断发展，社会对产品多样化的要求日益强烈，产品更新换代悦来越快，多品种、中小批量生产的比重明显增加，复杂形状的零件越来越多，精度要求也越来越高。此外，激烈的市场竞争要求产品研制生产周期越来越短，传统的加工设备和制造方法已难于适应这种多样化、柔性化与复杂形状零件的高效，高质量加工要求。因此，近几十年来，能有效解决复杂、精密、小批多变零件加工问题的数控加工技术得到了迅速发展和广泛应用，使制造技术发生了根本性的变化。

数控加工是根据被加工零件的图样和工艺要求，编制成以数码表示的程序输入到机床的数控装置或控制计算机中，以控制工件和工具的相对运动，使之加工出合格零件的方法。该项技术是20世纪40年代后期为适应加工复杂零件外形而发展起来的一种自动化加工技术。1948年，美国帕森斯公司接受美国空军委托，研制飞机螺旋桨叶片轮廓样板的加工设备。由于样板形状复杂多样，精度要求高，一般加工设备难以适应，于是提出计算机控制机床的设想。1949年，该公司在美国麻省理工学院私服机构研究室的协助下，开始数控机床的研究，并于1952年试制成第一台三坐标数控铣床，揭开了数控加工技术的序幕。

当时的数控系统采用电子管、继电器和模拟电路组成，体积庞大，价格昂贵，一般称之为第一代数控系统。1959年研制成晶体管和印刷电路的第二代数控技术，体积小，成本有所下降。1965年出现了第三代的集成电路数控系统，不仅体积小，功率低，而且可靠性提高，价格进一步下降，促进了数控机床品种和产量的发展。20世纪60年代末，先后出现了由一台计算机直接控制多台机床的直接数控系统，及采用小型计算机控制的计算机数控系统，使数控系统进入了以小型计算机化为特征的第四代。1974年，以微处理器为基础的cnc 系统问世，标志着数控系统进入第五代。

1.2 数控技术的特点

与普通机床加工相比，数控加工工具有如下的特点：

（1）自动化程度高

（2）具有加工复杂形状零件能力

（3）生产准备周期短

（4）加工精度高、质量稳定

（5）生产效率高

（6）易于建立计算机通信网络

当然，数控加工在某些方面也有不足之处，这就是数控机床价格昂贵，加工成本高，技术复杂，对工艺和编程要求较高，加工中难以调整，维护困难等。

1.3 数控机床的加工原理

在数控机床上加工零件时，要事先根据零件加工图样的要求确定零件加工的工艺过程，工艺参数和刀具参数，再按规定编写零件数控加工程序，然后通过手动数据输入方式或计算机通信等方式将数控加工程序送到数控系统，在数控系统控制软件的支持下，经过分析处理与计算后发出相应的指令，通过伺服系统是机床按预定的轨迹运动，从而控制机床进行零件的自动加工。

1.4 数控加工技术的主要应用对象

数控加工是一种可编程的柔性加工方法，但其设备费用相对较高，故目前数控加工主要应用于加工零件形状比较复杂，精度要求比较高，以及产品更换频繁，生产周期要求短的场合。集体的说，下面这些类型的零件最适合于数控加工。

（1）形状复杂，加工精度高

（2）公差带小，互换性高

（3）价值高的零件

（4）小批量生产零件

（5）钻，镗，铰，攻螺纹及铣削加工联合进行的零件

1.5 数控技术的发展趋势

1952年美国研制出世界上第一台数控铣床，开创了世界数控机床发展的先河。随后，德国、日本、苏联等国于1956年分别研制出本国第一台数控机床。我国于1958年由清华大学和北京第一机床厂合作研制出我国第一台数控铣床。近年来，由于引进了外国色数控系统与伺服系统的制造技术，使我国数控机床在品种、数量、和质量方面得到了迅速发展，缩短了与国外厂家的差距。在“九五”末期，国产数控机床的国内市场占有率达50%，配国产数控系统也达到了10%，2001年国内数控金属切削机床产量已达1.8万台。目前我国中档数控机床与国外产品无太大差别，但与国际先进水平还存在一定的差距，主要表现在：可靠性差，外观质量差，产品开发周期长，应变能力差等方面。

目前，国内外新一代数控系统的总体发展趋势是：

（1）数控系统采用开发方式体系结构。

（2）数控系统控制性能大大提高。

新一代数控系统技术水平大大提高，大大促进了数控机床性能的提高。当前，世界数控技术及其装备发展趋势主要体现在以下几个方面。

（1）高速、高效化。

（2）高精度化

（3）高可靠性

（4）模块化、专门化与个性化

（5）高柔性化

（6）复合化

（7）出现新一代数控加工工艺与装备

2．数控加工工艺

合理确定数控加工工艺对实现优质、高效和经济的数控加工具有极为重要的作用。其内容包括选择合适机床、刀具、夹具、走刀路线及切削用量等，只有选择合适的工艺参数及切削策略才能获得铰理想的加工效果。

2.1 数控加工工艺概述

从加工的角度看，数控加工技术主要是围绕加工方法与工艺参数的合理确定及其实现的理论与技术。数控加工通过计算机控制刀具做精确的切削加工运动，是完全建立在复杂的数值运算之上的，它能实现传统的机加工无法实现的合理、完整的工艺规划。

2.1.1 数控加工工艺的特点

（1）内容十分明确而具体

（2）工艺工作要求相当准确而严密

（3）采用多坐标联动自动控制加工复杂表面

（4）采用先进的工艺装备

（5）采用工序集中

2.1.2 数控加工工艺的主要能容

（1）选择适合在数控机床上加工的零件，确定数控机床加工内容

（2）对零件样图进行数控加工工艺分析，明确加工内容及技术要求

（3）具体设计数控加工工序

（4）处理特殊工艺问题

（5）编程误差及其控制

（6）处理数控机床上部分工艺指令

2.1.3 数控机床的合理选用

（1）形状尺寸适应性

（2）加工精度适应性

（3）节拍适应性

2.2 控加工工艺分析与工艺设计

数控机床加工中所有工部的刀具选择、走刀轨迹、切削用量、加工余量等都是要预先确定好并编入加工工序。

2.2.1 控加工工艺分析

数控加工工艺性分析涉及内容很多，在此仅从数控加工的必要性、可能性与方便性加以分析。

（1）决定零件进行数控加工的内容

1）优先选择通用机床无法加工的内容

2）重点选择通用机床难以加工或质量难以保证的内容

3）采用通用机床加工效率低，劳动强度大的内容

（2）零件的结构工艺性分析

1）零件的内腔和外形尽可能地采用统一的几何类型和尺寸

2）内槽圆角的大小决定了刀具直径的大小，因此内槽圆角不应过小

3）铣削零件的底面时，槽地圆角半径r不应过大

4）保证基准统一

2.2.2 数控加工工艺设计

数控加工工艺设计与普通加工工艺设计相似。

首先需要选择定位基准；再确定所有加工表面的加工方法和加工方案；然后确定所有工序的加工顺序，把相邻工步划为一个工序，即进行工序划分；最后再将需要的其他工序如普通加工工序，热处理等工序插入，并衔接于数控加工工序序列之中，就得到了要求零件的数控加工工艺路线。

3．数控编程基础

数控机床是一种按照输入的数字程序信息进行自动加工的机床。因此，零件加工程序的编制是实现数控加工的重要环节。所谓的编程就是把零件的图形尺寸、工艺过程、工艺参

数、机床的运动及刀具位移等按照CNC系统的程序段格式和规定的语言记录字程序上的全过程。

3.1 程序格式

数控加工工序是由一系列机床数控装置能辨识的指令有序结合而构成的，可分为程序号，程序段和程序结束等及部分。

3.1.1 程序段的格式和组成

程序段的格式可分为地址段，分隔顺序格式，固定程序段格式和可编程程序段格式等。

下面以N10程序段为例介绍程序段的格式

N10 G01 X 40.0 Z0 F0.2;

式中：

N：程序段地址码，用于指令程序段号；

G：指令动作方式的准备功能地址

X：坐标轴地址

F：进给量指令地址

3.1.2 程序号

目前计算机数控机床，都具有记忆程序的功能，能将程序存储在内存中。为了区分不同的程序，故在程序的最前端加上程序号码以区分。程序号码以地址O及1~9999范围内的任意数字组成。

如：

O 0001

O：程序号地址

0001：程序的编号

3.1.3 坐标字的表示方式

程序中控制刀具移动的指令中坐标字的表示方式有两种：用小数点表示法和不用小数点表示法。

（1）用小数点表示法

即数值的表示用小数点“.”明确的表示出个位的位置.

（2）不用小数点表示法

即数值中没有小数点,这时数控装置会将此数值乘以最小位移量作为输入数值。

3.2 数控程序的指令代码

数控程序所用的代码，主要有准备功能G代码，辅助功能M代码，进给功能F代码，主轴转速功能S代码和刀具功能T代码。在数控编程中，用各种G代码和M代码来描述工艺过程的各种操作和运动特征。

常用指令表

代码功能代码功能

G00 快速定位M00 程序停止

G01 直线插补M01 选择停止

G02 顺时针插补M02 程序结束

G03 逆时针插补M03 主轴正转

G04 程序暂停M04 主轴反转

G17 M05 主轴停止

G18 M08 切削液开

G19 M09 切削液关

G27 返回参考点检查M30 程序结束

G28 自动返回参考点M98 子程序调用

G29 从参考点返回M99 子程序结束并返回主程序G32 螺纹切削G99_F_ 每转进给

G33 G98_F_ 每分钟进给

G34 G50 S_ 主轴最高转速

G35 G96 S_ 恒线速度

G40 取消刀尖圆弧半径补偿G97 S_ 恒转速

G41 刀具左补偿T____ 换刀

G42 刀具右补偿

G50 工件坐标系

G70 精加工循环

G71 轴向粗车复合循环

G72 径向粗车复合指令

G73 仿形粗车循环

G76 螺纹车削多次循环

G90 轴向切削循环指令

G92 用于切削螺纹的循环指令

G94 径向切削循环指令

4．数控车床实例应用

下面以下图所示零件为例，介绍在数控车床上加工的程序方法。已知该零件毛胚为Φ85x45mm的棒料。

4.1 工艺方案订制

该零件在数控车床上分两次用三抓卡盘装夹加工。

第一次装夹加工工序为：

（1）钻Φ30底孔为Φ28

（2）端面及Φ80外圆粗加工，留0.2mm精加工余量

（3）Φ40及Φ30内孔粗加工至Φ39.7x16.85，Φ29.7

（4）端面及Φ80外圆精加工至Φ80x18

（5）Φ40精加工至Φ40x17

第二次装夹加工工序为：

（1）外圆粗加工（复合循环），留0.2mm精加工余量

（2）Φ30内孔精加工至Φ30x23

（3）外圆精加工至尺寸；

（4）车螺纹M50；

4.2 程序设计

加工程序单

程序号O 0001

序号程序内容程序说明

1 O 0001; 程序号

2 N1001 G28 U0 W0 X，z轴返回参考点

3 M00; 程序停止

4 G00 U_W_; X，z轴快速到达起刀点

5 M00; 程序停止

6 N1010 G9

7 S1000 T1100; 钻Φ30底孔至Φ28开始程序段

7 G50 X370.0 Z150.0 M08; 建立工件坐标系，冷却液开

8 G00 X0 Z10.0 T1111 M03; 建立刀具长度补偿，刀具正转

9 Z4.0; 快速进刀至z=4.0

10 G01 Z-45.0 F0.1; 钻孔至孔深

11 G00 Z4.0; 快速退刀

12 X370.0 Z150.0 T1100; 返回起刀点，取消刀具补偿

13 M01; 选择停止

14 N1100 G96 S120 T0100; 端面及Φ80外圆粗加工开始

15 G50 X370.0 Z150.0 M08; 建立工件坐标系

建立刀具补偿

16 G00 X90.0 Z0.2 T0101

M03;

17 G01 X28.0 F0.3; 车端面

18 G00 X80.4 Z1.0; 快速退刀至外圆加工起刀点

19 G01 Z-18.0; 粗车Φ18外圆

20 G00 X85.0 Z1.0; 快速退刀

21 X76.4; 快进至倒角起刀点

22 G01 U6.0 W-3.0; 倒角

23 G00 X370.0 Z150.0 T0100; 返回起刀点

24 M01; 选择停

25 N1200 G96 S120 T0300; Φ40及Φ30内孔粗加工开始

26 G50 X370.0 Z150.0 M08; 建立工件坐标系

27 G00 X28.0 Z10.0 T0303 M03; 建立刀具补偿

28 Z2.0; 刀具至循环起点

29 G90 X33.0 Z-16.85 F0.25; 单一固定循环第一次走刀粗车Φ

40孔

30 G00 X33.0; 刀具至循环起点

31 G90 X38.0 Z-16.85; 单一固定循环第二次走刀粗车Φ

40孔

32 G00 X38.0; 刀具至循环起点

33 G90 X39.7 Z-16.85; 单一固定循环第三次走刀粗车Φ

40孔

34 G00 X46.2; 快进至倒角起刀点

35 G01 U-5.5 W-2.75; 倒角

36 Z-16.9 R-0.5; 单一固定循环第四次走刀粗车Φ

40孔，倒角

37 X29.7 K-1.3; 车内孔台阶面，倒角

38 Z-43.0; 粗车Φ30内孔

39 G00 X28.0; x向退刀

40 Z10.0; Z向进刀

41 X370.0 Z150.0 T0300; 返回起刀点

42 M01; 选择停

43 N1300 G96 S180 T0500; 端面及Φ80外圆精加工开始

44 G50 X370.0 Z150.0 M08; 建立工件坐标系

建立刀补

45 G00 G42 X39.0 Z2.5 T0505

M03;

46 G01 Z0 F0.5; 至起始点

47 X80.0 K-1.0 F0.2; 精车端面，倒角

48 Z-18.0; 精车Φ80外圆

49 G00 G40 X370.0 Z150.0 T0500; 返回起刀点

50 M01; 选择停

51 N1400 G96 S180 T0700; 精车Φ40内孔开始

52 G50 X370.0 Z150.0 M08; 建立工件坐标系

53 G00 X40.0 Z10.0 T0707 M03; 建立刀补

54 G41 X46.0 Z2.0; 建立左刀补

55 G01 U-08.0 W-4.0 F0.08; 倒角

56 G00 Z1.0; Z轴退刀

57 X40.0; X轴进刀

58 G01 Z-17.0 R-1.0 F0.1; 精车Φ40内孔，倒角

59 X32.0; 车内孔台阶面

60 U-4.0 W-2.0; 倒角

61 G00 Z2.0; Z向进刀

62 G40 X370.0 Z150.0 T0700 M09; 返回起刀点

63 M02; 程序结束

64 M99 P1010 返回N1010程序段

结束语

先进制造技术是制造技术的最新发展阶段，是由传统的制造技术发展起来的，既保持了过去制造技术中的有效要素，又要不断吸收各种高新技术成果，并渗透到产品生产的所有领域及其全部过程。先进制造技术与现代高新技术相结合而产生了一个完整的技术群，它是具有明确范畴的新的技术领域，是面向21世纪的技术。近年来，我国的制造业不断采用先进制造技术，但与工业发达国家相比，仍然存在一个阶段性的整体上的差距。制造技术不仅是衡量一个国家科技发展水平的重要标志,也是国际间科技竞争的重点。我国正处于经济发展的关键时期,制造技术是我们的薄弱环节。只有跟上发展先进制造技术的世界潮流,将其放在战略优先地位,并以足够的力度予以实施,才能尽快缩小与发达国家的差距,才能在激烈的市场竞争中立于不败之地。总之,在我国研究和发展先进制造技术势在必行。

谢辞

本论文的完成，得益于陈尚坤老师传授的知识，使本人有了完成论文所要求的知识积累。在这里，特别感谢大学三年学习期间给我诸多教诲和帮助的各位老师，你们给予我的指导和教诲我将永远记在心里！

感谢和我一起生活3年的室友，是你们让我们的寝室充满快乐与温馨，“君子和而不同”，我们正是如此！愿我们以后的人生都可以充实、多彩与快乐！

感谢我的同学们，谢谢你们给予我的帮助！

回首本人的求学生涯，父母的支持是本人最大的动力。父母不仅在经济上承受了巨大的负担，在心里上更有思子之情的煎熬与望子成龙的期待。忆往昔，每次回到家时父母的欣喜之情，每次离家时父母的依依不舍之眼神，电话和信件中的殷殷期待和思念之语，皆使本人刻苦铭心，目前除了学习成绩尚可外无以为报，希望以后的学习、工作和生活能使父母宽慰。

参考文献

[1]杨叔子.机械加工工艺手册.北京机械工艺出版社，2002

[2]周济，周艳红.数控加工技术.北京国防工业出版社，2002

[3]李佳.数控机床及应用.北京清华大学出版社，2001

[4]李宏胜.机床数控技术及应用.北京高等教育出版社，2001

为你提供优秀的毕业论文参考资料，请您删除以下内容，O(∩_∩)O谢谢！！！Shanghai’s Suzhou Creek has witnessed much of the city’s history. Zhou Wenting travels this storied body of water and finds its most fascinating spots. Some lu cky cities can boast a great body

of water, like London with the river Thames and Paris with the river Seine. Shanghai is privileged enough to have two great bodies of water: Huangpu River and Suzhou Creek.Huangpu River became famous when colonists established clusters of grand buildings on its banks on what became known as the bund. Today, the bund overlooks the breathtaking skyline of Lujiazui financial district. Shanghai’s other body of water, however, Suzhou Creek, has been somewhat overshadowed. Suzhou Creek links the inland cities of Jiangsu province with Shanghai. When the British colonists, who arrived in the city after it was opened as a commercial port in 1843 found they could reach Suzhou, Jiangsu province, via the creek, they named it Suzhou Creek. Thanks to its location, a large amount of cargo and travelers were transported via the creek before rail links were established. But after a century of being utilized as a waterway to

transport goods and labor, the creek grew dark and smelly. Industrial factories were established along the banks. In the 1990s it became a key task of the city government to clean the creek. Suzhou Creek, which snakes 17 km from the iconic Waibaidu Bridge downtown to the outer ring road in west Shanghai, maps the changing periods of the city’s history, including the imprints of the concessions, the beginning of industrialization and the improvement in people’s living conditions. Where the Bund began In-between the shopping street of East Nanjing Road and the Bund, are a cluster of streets that give me the illusion that I am no longer in modern Shanghai. The streets are narrow and old and criss-cross each other. Any old residential house may turn out to be a former office of the British, constructed

in the 1880s. Pawnshops and hardware stores that are hard to find elsewhere, are plentiful here. This area, at the confluence of Huangpu River and Suzhou Creek, is called the Bund Origin. Countless tour buses stop at the site every day and visitors from around the world get off to see this place, the starting point of the concessions in the city. It all started in 1872, when the former British Consulate General was constructed and the Bund began its

transformation into an the financial street of the East. Now the site of the former consulate is called “No 1 Waitanyuan”, which translates to “the Bund

Origin”, to honor its beginnings. The entire complex of this historical site comprises of five buildings, the former British Consulate General, the official residence of the consul, the former Union Church, the church apartments and the former Shanghai Rowing Club. The size of the courtyard is equivalent to that of four standard soccer fields. The building of the former consulate is a two-storey masonry

building on an H-shaped plan in typical English

renaissance style. The building is designed with

a five-arch verandah on the ground floor with a

raised terrace facing the garden, while the facade

features an entry portico beneath a colonnaded loggia. It has been turned into a café where dinner and

afternoon tea are available. Visitors can choose to sit indoors or outdoors to enjoy the magnificent gardens with nearly 30 ancient trees.

Yuanmingyuan Road behind the complex is also a historical site. The road has been revamped as

a pedestrian shopping street and high-end brands have seized the best spots. Altogether,

14 old buildings, including those used for offices and residences constructed during 1920s and 1930s, remain. Today, it is a popular location for commercial fashion photo shoots.N ew Tian’an Church, or Union Church, stands at the intersection of Yuanmingyuan Road and Suzhou Creek. The church, designed in the style of the English countryside, has a capacity of 500 people.

It was very popular during the concession period but was converted into factory offices after 1949. The church we see today is a replica, the original burned down in 2007. There used to be an outdoor swimming pool, the first of its kind in Shanghai, beside the church but has been filled-in and is now a small garden. Bridge of romance There is perhaps no other place that’s more representative of Shanghai than

this bridge, which appears in

quite a lot of movies about the

city. Dozens of couples visit

every day to pose for their pre-

wedding photos on the bridge

where Suzhou Creek begins

and interconnects with

Huangpu River. This is

Waibaidu Bridge, or the

Garden Bridge. The soon-to-be-

wed couples pose in splendid

attire on the bridge, leaning

against the railing or sitting on

the wooden floor. Some even

risk walking into the middle of

the road to get the perfect

shot.Colorful lights illuminate the bridge

throughout the night, making it a picturesque place for pre-wedding portraits and lovers

to meet. Constructed in 1873 and designed by a British company, the 106-meter-long bridge was the first-ever major bridge in Shanghai. In 1856, the first large wooden bridge, Wells Bridge, was built over Suzhou Creek but the bridge toll led to complaints from citizens. So 17 years later, another wooden bridge, which did not require toll s, was built. People called it Waibaidu, which means “going across for free”. The bridge was renovated as a steel truss structure in 1907. Because nearly 40 bridges have now been built over Suzhou Creek, the bridge is no longer a traffic artery but is more of an observation deck for tourists. It is a tradition in Shanghai for a grandmother to walk across a bridge with their grandchild when he or she reaches one month. This represents that the newborn has overcome all the twists and turns and its journey wil l be safe and smooth throughout his or her life. "Waibaidu Bridge is always the best option because it’s the icon of Shanghai. The picture of my daughter when she was a baby held by her grandmother was also taken here. It’s like a family tradition," says W ang Xuefen, a Shanghai native who has a newborn grandson. Changning Riverside There is a 5-km stretch of waterfront by Suzhou Creek in Changning district on Changning Road from the intersection of Hami Road to Jiangsu Road. It has become a popular place to take a walk and sunbathe on the lawn. There is an overpass at the intersection of Changning Road and Gubei Road for people to enjoy the view of the creek and a 3-

km plastic runway on both sides of Changning Road, which attracts people of all ages, Chinese and expat. "Jogging on the two sides gives a different feeling because the north side is next to the creek, and the south side is adjacent to the residential highrises, which is like jogging in the jungle," says Xiao Xu, a 27-year-old woman who lives nearby. The riverside used to be completely different. Dozens of textile mills, chemical plants and machine manufacturing factories were set up along the creek in the 1920s. They brought industrialization but also pollution. From the 1930s the creek could no longer be used as a source for tap water, and no living fish or shrimp could be found. "Suzhou Creek in my memory is dark and smelly. I used to go to the riverbank to watch the sewage disposal running out from the chemical plants when I was a little girl. W e didn’t know it was pollution. We thought it was a red waterfall," says Huang Qi, a 57-year-old Shanghai resident. "So the residential houses along the creek were unpopular, and only migrants with low incomes would live in that area," she says. However,

things have changed. The plants were closed and turned into riverside parks and the apartments in the new highrises, especially those facing the creek, are much sought after. East China University of Political Science and Law This is the famous former Saint John’s University, China’s first-ever modern institution of higher education established by missionaries from the United States in 1879. The buildings combine Chinese and Western elements. Address: 1575 Wanhangdu Road, Changning district The old residential area After you leave the university from its east gate you will enter a shabby neighborhood that retains its original look. The alleys are narrow and the houses are overcrowded. Some things have not changed for many generations, such as raising chickens at home. Address: West Guangfu Road Moganshan Road This is an artsy street that has become very popular among artists and fashionistas in recent years. Graffiti covers the walls on the winding street, where you can find a cluster of art galleries and creative industry offices. Sihang Warehouse Four banks jointly funded the construction of this warehouse, so it is named sihang, or four banks. The warehouse, built in 1931, was used for the storage of food, first-aid supplies and ammunition during the years of war. The building, which is also a masterpiece left by the Hungarian architect Laszlo Hudec in the 1930s, has been recently transformed into a center of creative industry workshops. Address: 1 Guangfu Road, Zhabei district