Method and apparatus for designing sheet metal parts

An apparatus for resolving a collision between a first face and a second face of a sheet metal part represented by a 3-D model, the faces colliding with one another as a result of a 2-D model of a flat sheet metal part designed on a CAD system being folded into the 3-D model displayed on the CAD system, the apparatus comprising:

• a detector that detects each collision between the faces becoming adjacent when the 2-D model is folded into the 3-D model;
• a classifying system that determines whether the colliding faces are parallel;
• a bounding box computing system that computes a first bounding box of a first collision area corresponding to the first face, and a second bounding box of a second collision area corresponding to the second face, the bounding boxes completely containing all points in the collision areas;
• and
• a re-design system that calculates a trim-loop based upon the first and second bounding boxes, the model being trimmed by the trim-loop so that the collision is eliminated and a smooth transition results between the faces after bending a re-designed 2-D model into a revised 3-D model.

A method for resolving a collision between a first face and a second face of a sheet metal part represented by a 3-D model, the faces colliding with one another as a result of a 2-D model of a flat sheet metal part designed on a CAD system being folded into the 3-D model displayed on the CAD system, the method comprising:

• detecting each collision between the faces becoming adjacent when the 2-D model is folded into the 3-D model;
• determining whether the colliding faces are parallel;
• computing a first bounding box of a first collision area corresponding to the first face, and a second bounding box of a second collision area corresponding to the second face, the bounding boxes completely containing all points in the collision areas;
• and
• re-designing the 2-D model based upon a trim-loop calculated based upon the first and second bounding boxes, the 2-D model being trimmed by the trim-loop, so that the collision is eliminated and a smooth transition results between the faces after bending the re-designed 2-D model into a revised 3-D model.

A method for extending at least one of two faces of a sheet metal part, represented by a 3-D model, so that a gap between the two faces is reduced, the extension being reflected in the design of a 2-D model of the sheet metal part so that when the 2-D model is folded into the 3-D model, the gap is reduced, the method comprising:

• selecting an edge of a first face to extend;
• selecting a target face to which the first face will be extended, the target face defining a target plane;
• selecting an extension direction along which the edge of the first face will be extended to the target face;
• and
• designing a modified part that reduces the gap based on the selected edge, target face, and extension direction.

A method for resolving a collision between a first bendline and a second bendline of a sheet metal part represented by a 3-D model, the bendlines colliding with one another as a result of a 2-D model of a flat sheet metal part designed on a CAD system being folded into the 3-D model displayed on the CAD system, the method comprising:

• detecting the collision between the bendlines in the 3-D model;
• computing 3-D polyline corresponding to a collision area;
• computing 2-D polylines from the 3-D polylines;
• computing a cut-loop from the 2-D polylines;
• and
• refining the 2-D model by using the cut-loop to remove a portion of the 2-D model of the flat sheet part so that a two radius corner results in a revised 3-D model where the bendlines intersected, when the refined model is folded into the revised 3-D model.