Method of and apparatus for unfolding a sheet metal part employing a CAD apparatus
First Claim
Patent Images
1. A method of unfolding sheet metal part employing a CAD apparatus, which comprises:
- a first step in which a three-dimensional surface model of a sheet metal part provided by a data input device is decomposed into pattern entities through the scanning movement of a three-dimensional scanner having a scanning axis whose length is equal t the thickness of the sheet metal forming the sheet metal part, and the pattern entities thus obtained are classified into groups;
a second step in which auxiliary lines are generated, each auxiliary line connecting an end point of one of the pattern entities of an internal shape of the sheet metal part and an end point of a pattern entity of an external shape forming a plane including the end point of the pattern entity of the internal shape;
a third step in which the three-dimensional surface model decomposed in the first step is reconstructed into a reconstructed three-dimensional surface model by assembling the pattern entities and the auxiliary lines, and the reconstructed three-dimensional surface model is unfolded into a two-dimensional pattern on the basis of a scanning operation of the three-dimensional scanner in which the external shape of the reconstructed three-dimensional surface model is scanned by the three-dimensional scanner having the scanning axis corresponding to the thickness of the sheet metal and the loci of the thus obtained three-dimensional scanner is unfolded into the two-dimensional reference plane;
a fourth step in which a decision is made on the basis of the direction of the scanning as of the scanning three-dimensional scanner as to whether or not the sheet metal part has any bend, the length of a pattern entity corresponding to an unfolded bend unfolded in the third step when the sheet metal part has a bend or bends, and a bending line or lines are added to the unfolded two-dimensional pattern;
a fifth step in which a decision is made as to whether or not the reconstructed three-dimensional surface model has any auxiliary lines and, when the reconstructed three-dimensional surface model has an auxiliary line or lines, the auxiliary line or lines and a pattern entity or entities of the internal shape connecting with the auxiliary line or lines are unfolded; and
a sixth step in which an unfolded pattern or patterns corresponding to the auxiliary line or lines ar deleted from the unfolded pattern of the three-dimensional surface model after the completion of the scanning operation of the three-dimensional scanner.
1 Assignment
0 Petitions
Accused Products
Abstract
A method of and apparatus for unfolding a sheet metal part has a three-dimensional scanner which is moved along the profile of a three-dimensional surface model to decompose the three-dimensional surface model into groups of pattern entities. Auxiliary lines interconnecting the end points of pattern entities of the internal shape of the sheet metal part and the end points of the pattern entities of the external shape of the sheet metal pattern including the end points of the pattern entities of the internal shape are produced. An unfolding three-dimensional surface model is constructed by assembling the pattern entities and the auxiliary lines, and then the reconstructed three-dimensional surface model is scanned by the three-dimensional scanner to unfold it into a two-dimensional unfolded pattern. Bends in the sheet metal part are detected from the variation of the direction of the scanning axis of the three-dimensional scanner, the length of the pattern entities each having a portion corresponding to a bend is corrected by a bending allowance, and a bending line is added to the unfolded pattern at a position corresponding to a bend. When the three dimensional surface model has an auxiliary line, the pattern entities of the corresponding internal shape are unfolded, and then the auxiliary line is selected after the completion of the scanning operation.
64 Citations
2 Claims
-
1. A method of unfolding sheet metal part employing a CAD apparatus, which comprises:
-
a first step in which a three-dimensional surface model of a sheet metal part provided by a data input device is decomposed into pattern entities through the scanning movement of a three-dimensional scanner having a scanning axis whose length is equal t the thickness of the sheet metal forming the sheet metal part, and the pattern entities thus obtained are classified into groups; a second step in which auxiliary lines are generated, each auxiliary line connecting an end point of one of the pattern entities of an internal shape of the sheet metal part and an end point of a pattern entity of an external shape forming a plane including the end point of the pattern entity of the internal shape; a third step in which the three-dimensional surface model decomposed in the first step is reconstructed into a reconstructed three-dimensional surface model by assembling the pattern entities and the auxiliary lines, and the reconstructed three-dimensional surface model is unfolded into a two-dimensional pattern on the basis of a scanning operation of the three-dimensional scanner in which the external shape of the reconstructed three-dimensional surface model is scanned by the three-dimensional scanner having the scanning axis corresponding to the thickness of the sheet metal and the loci of the thus obtained three-dimensional scanner is unfolded into the two-dimensional reference plane; a fourth step in which a decision is made on the basis of the direction of the scanning as of the scanning three-dimensional scanner as to whether or not the sheet metal part has any bend, the length of a pattern entity corresponding to an unfolded bend unfolded in the third step when the sheet metal part has a bend or bends, and a bending line or lines are added to the unfolded two-dimensional pattern; a fifth step in which a decision is made as to whether or not the reconstructed three-dimensional surface model has any auxiliary lines and, when the reconstructed three-dimensional surface model has an auxiliary line or lines, the auxiliary line or lines and a pattern entity or entities of the internal shape connecting with the auxiliary line or lines are unfolded; and a sixth step in which an unfolded pattern or patterns corresponding to the auxiliary line or lines ar deleted from the unfolded pattern of the three-dimensional surface model after the completion of the scanning operation of the three-dimensional scanner.
-
-
2. An apparatus for unfolding a sheet metal part employing a CAD apparatus including a pattern display unit, a pattern operating data input unit, a position data input unit, a pattern processing unit, and a pattern memory, wherein said CAD apparatus further includes an automatic sheet metal part unfolding unit comprising:
-
a three-dimensional scanning means for scanning a three-dimensional surface model of a sheet metal part along surfaces of the model representing the thickness of the sheet metal forming the sheet metal part and for decomposing the three-dimensional surface model into two part surface entities, entities interconnecting the two part surface entities and entities of a bend or bends; a closed pattern group interconnection means for producing an auxiliary line for interconnecting a group of entities forming the external profile of the sheet metal part, and a group of entities forming the internal profile of the sheet metal part such as punched hole or holes; a part surface interconnection means for assembling the entities obtained by decomposing the three-dimensional surface model to reconstruct a reconstructed three-dimensional surface model; a part surface memory means for storing data representing the shape of one of two major part surfaces of the sheet metal part; a part surface memory means for storing data representing the shape of the other of the two major part surfaces of the sheet metal part; a part surface interconnecting entity memory means for storing data representing entities interconnecting the two major part surfaces; a bend entity memory means for storing data representing entities of a bend or bends; an unfolding controller means for determining an unfolded pattern; and an unfolding data memory means for storing unfolding data for producing an unfolded pattern of the sheet metal part.
-
Specification
-
- Resources
Litigation Campaign Assessment
Thank you for your request. You will receive a custom alert email when the Litigation Campaign Assessment is available.
×
-
Current AssigneeOKI Electric Industry Company Limited
-
Original AssigneeOKI Electric Industry Company Limited
-
InventorsHaga, Takeshi, Aoyama, Yoshitada
-
Primary Examiner(s)MacDonald, Allen
-
Application NumberUS07/360,029Time in Patent Office299 DaysField of Search364/472, 364/521, 364/522, 364/518, 364/300US Class Current700/98CPC Class CodesG06T 17/10 Constructive solid geometry...
