Formed panel and associated method

Abstract

An improved method of forming a panel out of a workpiece, the panel being substantially free of ripples and free of ruptures, includes forming a number of smooth bulges in the workpiece in order to effectively spread a quantity of excess material that results from forming a number of desirable features into the workpiece by taking up in the bulges an amount of material. The quantity, dimensions, locations, orientations, shapes, and configurations of the bulges with respect to the features are determined by an iterative process that examines the degree to which the excess material resulting from formation of the features is effectively spread about the panel. Effective material spreading can be characterized by at least one of reduced thickening of the workpiece, reduced amplitude of ripples in the workpiece, and increased period of the ripples. An improved panel formed according to the aforementioned process is also disclosed.

What is claimed is:  
     
         1 . A method of forming a metal panel out of a workpiece, the method comprising: 
 forming a feature into the workpiece;    drawing away a quantity of excess material of the workpiece from a region of the workpiece;    avoiding fracturing the workpiece; and    resisting the formation of visible wrinkling in the region.    
     
     
         2 . The method of  claim 1  wherein 
 said drawing away a quantity of excess material includes forming a bulge into the workpiece and drawing generally toward the bulge at least a portion of the excess material.  
 
     
     
         3 . The method of  claim 2  wherein 
 said forming a bulge in the workpiece includes selecting a configuration for the bulge to resist the formation of visible wrinkling in the region during said forming a feature in the workpiece.  
 
     
     
         4 . The method of  claim 3  wherein 
 said selecting a configuration for the bulge to resist the formation of visible wrinkling includes selecting a configuration for the bulge to effectively spread at least a portion of the excess material away from the region.  
 
     
     
         5 . The method of  claim 2  wherein 
 said drawing away a quantity of excess material includes effectively spreading at least a portion of the excess material away from the region.  
 
     
     
         6 . The method of  claim 5  wherein 
 said effectively spreading includes at least one of:  
 reducing the amplitude of a number of ripples formed in the region;  
 increasing the period of the ripples formed in the region; and  
 resisting thickening of the workpiece in the region.  
 
     
     
         7 . The method of  claim 5  wherein 
 said effectively spreading includes determining a distribution of thickening along a portion of the workpiece, and selecting a configuration for the bulge to spread the distribution of thickening along the at least portion of the workpiece.  
 
     
     
         8 . The method of  claim 2  wherein 
 said forming a bulge in the workpiece includes forming the bulge in a location that is spaced from the region.  
 
     
     
         9 . The method of  claim 2  wherein 
 said forming a bulge in the workpiece includes forming a substantially smooth bulge.  
 
     
     
         10 . The method of  claim 2  wherein 
 said forming a bulge in the workpiece includes forming a first bulge portion and forming a second bulge portion, the second bulge portion being at least partially disposed on the first bulge portion.  
 
     
     
         11 . The method of  claim 10  wherein 
 said forming a first bulge portion includes forming the first bulge portion to protrude outwardly from the workpiece in a first direction;  
 said forming a second bulge portion including forming the second bulge portion to at least partially extend from the first bulge portion in a second, different direction.  
 
     
     
         12 . The method of  claim 11  wherein 
 said forming the second bulge portion to at least partially extend from the first bulge portion in a second, different direction includes forming the second bulge portion to at least partially extend from the first bulge portion in a substantially opposite direction.  
 
     
     
         13 . The method of  claim 2  wherein 
 said forming a bulge includes forming a bulge having a perimeter;  
 said taking up a quantity of excess material including drawing at least a portion of the quantity of excess material from a location disposed on a perpendicular to a tangent to the perimeter at a point on the perimeter, the perpendicular extending through the point.  
 
     
     
         14 . A method of characterizing a degree of wrinkling of a metal workpiece resulting from forming a feature into the workpiece, the method comprising: 
 determining the degree of effective spreading of excess material that results from formation of the feature, said determining the degree of effective spreading including at least one of: 
 determining an amplitude of a ripple in the workpiece;  
 determining a period of a ripple in the workpiece; and  
 determining a change in thickness of the workpiece along a portion of the workpiece.  
   
     
     
         15 . The method of  claim 14  wherein 
 said determining a change in thickness includes determining a length for the portion of the workpiece along which the change in thickness occurs.  
 
     
     
         16 . The method of  claim 15  further comprising 
 providing a characterization of the degree of wrinkling based upon both the change in thickness and the length.  
 
     
     
         17 . The method of  claim 15  wherein 
 said determining a change in thickness of the workpiece along a portion of the workpiece includes determining a range of the change in thickness along the portion of the workpiece.  
 
     
     
         18 . The method of  claim 17 , further comprising 
 determining a peak change in thickness in the range of the change in thickness.    
     
     
         19 . The method of  claim 17  wherein 
 said determining a range of the change in thickness along a portion of the workpiece includes determining a nonzero minimum change in thickness and a peak change in thickness along the portion of the workpiece.  
 
     
     
         20 . The method of  claim 15  wherein 
 said determining a change in thickness of the workpiece includes determining the change in thickness as a percentage change in thickness.  
 
     
     
         21 . A metal panel having a minimum of wrinkling while avoiding rupturing thereof during the forming process, the panel including an area that is structured to take up excess material during the forming process.  
     
     
         22 . The panel of  claim 21  wherein 
 the area includes a substantially smooth bulge.  
 
     
     
         23 . The panel of  claim 22  wherein 
 the bulge protrudes from a portion of the panel surrounding the bulge.  
 
     
     
         24 . The panel of  claim 23  wherein 
 the bulge includes a first bulge portion and a second bulge portion;  
 the first bulge portion protruding from the panel;  
 the second bulge portion being at least partially disposed on the first bulge portion.  
 
     
     
         25 . The panel of  claim 24  wherein 
 the first bulge portion protrudes outwardly from the panel in a first direction;  
 the second bulge portion protruding from the first bulge portion in a second, different direction.  
 
     
     
         26 . The panel of  claim 25  wherein 
 the second bulge portion protrudes from the first bulge portion in a substantially opposite direction.  
 
     
     
         27 . The panel of  claim 22  wherein 
 the bulge includes a perimeter, and wherein at least a portion of the excess material out of which the bulge is formed includes material drawn from a location disposed on a perpendicular to a tangent to the perimeter at a point on the perimeter, the perpendicular extending through the point.  
 
     
     
         28 . The panel of  claim 22  wherein 
 the bulge is asymmetric.  
 
     
     
         29 . The panel of  claim 21  wherein 
 the panel includes a feature formed therein, the excess material resulting at least in part from formation of the feature.  
 
     
     
         30 . The panel of  claim 29  wherein 
 the bulge is disposed at a location that is spaced from the feature.