Deformation

The current technology of sheet metal, in small and medium thickness, is largely based on processes of punching and bending on CNC machinery. Both processes have experienced a recent boom by introducing a high flexibility due to two phenomena: on the one hand the current improvements in machines, supplies and tools and on the other to improvements in the numerical controls and the CAD/CAM systems for its automatic programming. The latter have been able to implement and optimize the use of the modern types of tools as well as the possibilities of the punching machines and CNC folding.

However, from the point of view of the cost calculation and study of time of manufacture, the CAM systems for sheet metal, and in particular for punching, they have not followed the same development. Advances in both useful flexibility of machine, such as the repositioning of sheet, use of multitool, autoindexadas tools (autoindex), automatic controls for expelling hatch of cuts, etc. has not but complicate and add a huge number of parametersthat previously did not were taken into account and that away estimates of calculation time and costs of the actual values that will arise at the time of manufacture (punching) Royal of plate or plates that make up the order.

To cite some of the main variables, include here:

• The possibility of shaping, threading, destalonar and even flush mounted with special tools, operations which get times totally different each other and different turn of "loose shock"

• The operations of engraving and the machining by chewing (nibling), that are made with speed, displacement and cutting area completely different which would have the same useful in the case of loose coup. This requires totally different tool life equations when is utili-zan (chewing) one way or another (loose blow).

• Possibility of ordering satisfied it several sheets of game, with different materials and thicknesses and even the use of machines combined laser-punching, with change of head even on the same sheet.

And if these factors we add the need to cover the cost (and time) total cost per piece or cost per batch, will understand that the number of CAM systems for punching that have been developed and include modules of costs is extremely small and very basic solutions.

This paper focuses on the study, definition and calculation of the cost and time aso-CLADES to punching of sheet metal work taking into account all these factors, and proposing an algorithm to give solution to most of the philosophies and ways of working of each company.

[1] J.C. Rico, e. Hill, S. Mateos, C. M. Suárez, analysis using an integrated CAD/CAM system of time and costs associated with the cutting of sheet metal, metal deformation, no. 229, p. 33-42, 1996.

[2] E. Cuesta, J.C. Rico, S. Mateos, C. M. Suárez, Times and Costs analysis for sheet-metal cutting processes in an integrated CAD/CAM system, Int. Journal of Production Research, Vol. 36, p. 1733-1747, 1998