Automatically programmed tools

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APT (Automatically Programmed Tools) is an application-related programming language for generating control information for machine tools .

APT was developed in the USA in the 1950s and coded in Fortran IV in order to be able to describe complex production tasks for NC and CNC production machines in a problem-related manner, e.g. B. on wing connections in aircraft construction . APT primarily allows a machining geometry description, but has also undergone technological extensions in many APT dialects .

One of the best-known extensions is EXAPT , " EX tended Subset of APT ". The EXAPT Association was founded in Germany in the 1970s at the Universities of Stuttgart and Aachen with the involvement of industrial companies such as EXAPT Systemtechnik GmbH in order to further develop the APT language.

Code sample

An APT program is described in sentences (formerly called "cards"). A part program always begins with a PARTNO block and ends with a FINI block. A simple example of milling along a line:

PARTNO / EXAMPLE

$$ parameters, variables, coordinates D0 = 200 D1 = 180 F1 = 0.1 X0 = 0 Y0 = 0 X1 = 100 Y1 = 50

$$ Geometry definitions P0 = POINT / X0 , Y0 P1 = POINT / X1 , Y1 L1 = LINE / P0 , P1 $$ Define line through points P0 and P1

$$ Technology TOOLNO / 1 $$ Selection of the first tool, milling cutter SPINDL / 300, CCLW $$ Speed ​​300 1 / min counterclockwise FROM / 0,0,100 $$ Approach from Z coordinate 100 above the workpiece RAPID $$ Rapid traverse ZSURF / 10 $$ move to 10 mm above the workpiece GOTO / P0 $$ approach defined zero point PLGFED / 0.15 $$ switch to Z-axis feed / deselect rapid traverse ZSURF / 0 $$ specify new reference plane in Z GOTO / P0 $$ Approach new Z coordinate 0 in feed, workpiece surface. FEDRAT / F1 $$ switch on feed for milling plane x / y GOTO / P1 $$ approach point P1 at an angle on the surface RAPID $$ rapid traverse on GODLTA / 20 $$ lift 20 mm in the Z direction STOP $$ stop spindle

FINI

APT sentences always have a noun with up to six letters; the secondary words, determining secondary information, are separated by the slash "slash".

By changing the parameters , this simple line milling program can be adapted to all production tasks. If the machining task changes (for example to wire EDM instead of milling ), only the technology part needs to be changed; the geometry description of the workpiece remains unchanged.

APT contains extensive options for systematically describing processing tasks, such as conditional and unconditional jumps, jump instructions , loops , subroutines .

APT itself cannot be bought directly, but a number of commercially available CNC programming systems are APT-based.

See also

literature

  • Douglas T. Ross, Clarence G. Feldmann, David F. McAvinn: The automatically programmed tool system. Ed .: Massachusetts Institute of Technology. 7 volumes. Cambridge, Mass. 1959, OCLC 15264910 .
  • Shimon Y. Nof: Computer-Assisted Part Programming: APT and EXAPT . In: Springer Handbook of Automation . Springer Science & Business Media, Berlin 2009, ISBN 978-3-540-78831-7 , p. 846 ( books.google.de - restricted reading sample).
  • Helmi A. Youssef, Hassan El-Hofy: Machining Technology: Machine Tools and Operations . CRC Press, Boca Raton, Fl. 2008, ISBN 978-1-4200-4340-2 , pp. 334 ( books.google.de - restricted reading sample).