Patent FR-2911807-A1 (FR)
Title: Cutting parts predefined in a material made of several layers, comprises locating coordinates of reference points in the material by moving the corresponding part, and superposing the pattern according to the placement of reference points
Inventor: BARBE STEPHANE
IPC: B23K26/03
Filed: 2007-01-29
Abstract: The process for cutting parts that are predefined in a material made of several layers, comprises locating coordinates of reference points in the material by moving the corresponding part, superposing the pattern according to the placing of reference points by applying a size adaptation for correcting any deformation of the part, automatically checking the dimensions of deformed pattern to ensure that it meets predefined size tolerances, and cutting the part according to the deformed pattern with the location of coordinates corresponding to following part to be cut in the material. The process for cutting parts that are predefined in a material made of several layers, comprises locating coordinates of reference points in the material by moving the corresponding part, superposing the pattern according to the placing of reference points by applying a size adaptation for correcting any deformation of the part, automatically checking the dimensions of deformed pattern to ensure that it meets predefined size tolerances, and cutting the part according to the deformed pattern with the location of coordinates corresponding to following part to be cut in the material. Each part comprises a pattern of predetermined geometry and a point of reference corresponding to predetermined coordinates in the pattern. The automatic checking of the dimensions of the deformed pattern is carried out by defining an external tolerance envelope corresponding to an image of the pattern to cut into largest dimension, defining an internal tolerance envelope corresponding to an image of the pattern to cut into smallest dimension, superposing the envelopes of tolerance compared to their respective reference point, defining a surface of tolerance resulting from the difference between the surfaces defined by the external and internal envelope, applying the deformed pattern on the superposed envelopes of tolerance, and verifying each contour point of deformed pattern of the part belonging on the surface of tolerance. Each envelope of tolerance comprises a same reference point of which the coordinates in the envelope correspond to the reference point (F) of the part to be cut. The contour point verification is carried out by calculating the number of intersections between a straight line that connects a contour point of the pattern deformed at an external point and the contour of envelopes of internal and external tolerance, and deciding belonging or non-belonging of contour point on the surface of tolerance. The material has a grid constituted of lines parallel to the longitudinal and transversal directions of material movement. The lines forming the grid are automatically identified and then the damaged lines having missing parts are reconstituted by calculating the average points forming lines. An independent claim is included for a process for automatic checking of the size of a part to be cut in a material made of several layers.