2.8 Automatic Programming manual programming: program written in word address trigonometry was a must for tool paths ↓ machine halted while keying the program need to verify the program and involve machining a test part cannot program some difficult parts Computer changed the way programs are written ， checked ， and run ( dramatic improvements by the computer include off-line programming ， use of computer-aided programming languages ， application of CAD ／ CAM )

2.8.1 Computer-aided programming language A computer-aided programming language allows the programmer to write the program using English- like commands ， not G and M codes ． trigonometric computations are not needed, programmer need not tailor the program to a particular controller (A file known as a postprocessor can translate the program into a corresponding word address program)

The computer’s role ： ① input translation ，② numerical values ， ③ editing ， and ④ post processing

2.8.2 Interactive computer graphics part programming inconveniences with APT: difficult to describe complicated geometric drawing short of direct-vision difficult to connect to CAD and CAM database → three-dimensional designs, analysis and NC integrated manufacturing automatic programming systems: CATIA ， Pro ／ Engineering ， MasterCAM ， UGII ， I-DEAS ， Cimatron ， SolidWorks ， etc ．

interactive graphics programming system : faster speed ， higher precision ， better direct-vision ， etc ． → programs complex parts The programming steps: analyzing part drawing and machining technology ， geometric modeling ， selecting tools ， working out parameters ， Computing tool path ， producing the tool path, post-processing ， outputting the program ， etc ．

(1)Geometric modeling Geometric modeling involves the use of a CAD system to develop a mathematical description of part geometry

(2) Producing tool path

刀具参数 切入切出方式

切削用量 下刀方式 加工边界

(3) Post-process 包括 “ 后置设置 ” 、 “ 生成 G 代码 ” 和 “ 校核 G 代码 ” 等功能 后置设置 : 包括【机床信息】和【后置设置】设置

机床信息选项设置

后置设置选项

UG example 型腔模型

外形粗加工仿真

内腔精加工仿真

上表面加工仿真

下面是所生成的 NC 代码。 % N0010G40G17G80G90 N0011T01M06 N0012G43H01Z100. N0013G54 N0014G00Y10.598S0X-.267M13 N0015G00Z29. N0016G00Z5. N0017G41G01Y10.424Z4.61F250D11X N0018G01Y9.82Z4.148X N0019G01Y8.85Z3.686X N0020G01Y7.57Z3.224X N0021G01Y6.43Z2.872X N0022G01Y4.79Z2.41X-7.095

N0023G01Y3.071Z1.948X N0024G01Y1.37Z1.486X N0025G01Y-.215Z1.024X N0026G01Y-1.595Z.562X N0027G01Y-2.69Z.1X N0028G01Y-3.44Z-.362X N0029G01Y-3.8Z-.824X-.658 N0030G01Z-1.X0.0 …… …… 

N1950G03Y I7.J0.0X101. N1951G00Z29. N1952G40 N1953Z100. N1954G00Y S0X-101.M13 N1955G00Z N1956G41G01Z-24.75F250 N1957G03Y-77.I-4.J5.745X-98. N1958G01Y77.Z N1959G03Y82.745I-7.J0.0X-101. N1960G00Z29. N1961G00Z200. N1962G00Y0.0X0.0 N1963G40 N1964G49Z200. N1965M02 %