Method of forming a surface finished workpiece for a vehicle from a metal sheet

Abstract

In at least one embodiment of the present invention, a method of forming a surface finished workpiece for a vehicle from a metal sheet is provided. The workpiece is machined, which generates string chips having a desired maximum length for removal from the workpiece. The method comprises stamping the metal sheet into a blank having an edge with a contour, wherein the edge includes a plurality of interrupting segments spaced apart. Stamping the blank into the workpiece. Machining at least a portion of the workpiece to within a surface tolerance, wherein the edge is a stamping precursor of the portion, whereby the generated string chips break at interrupting segments such that the lengths are less than the desired maximum.

1 . A method of forming a surface finished workpiece for a vehicle from a metal sheet, wherein machining of the workpiece generates string chips having a desired maximum length for removal from the workpiece, the method comprising:
 stamping the metal sheet into a blank having an edge with a contour, wherein the edge includes a plurality of interrupting segments spaced apart;   stamping the blank into the workpiece; and   machining at least a portion of the workpiece to within a surface tolerance, wherein the edge is a stamping precursor of the portion, whereby the generated string chips break at the interrupting segments such that the lengths are less than the desired maximum.   
   
   
       2 . The method according to  claim 1  further comprising removing the string chips from the workpiece. 
   
   
       3 . The method according to  claim 1  wherein the geometry of the edge contour is substantially curved and the interrupting segments are substantially flat. 
   
   
       4 . The method according to  claim 1  wherein the interrupting segments are equally spaced apart. 
   
   
       5 . The method according to  claim 1  wherein the edge defines a substantially circular blank. 
   
   
       6 . The method according to  claim 1  wherein the step of stamping the blank into the workpiece depressively reshapes the geometry of the interrupting segments. 
   
   
       7 . The method according to  claim 6  wherein the reshaped segments have a scalloped geometry. 
   
   
       8 . The method according to  claim 6  wherein the reshaped segments have a slotted geometry. 
   
   
       9 . The method according to  claim 1  wherein the interrupting segments are depressions. 
   
   
       10 . The method according to  claim 1  wherein the step of stamping the blank into the workpiece does not substantially reshape the interrupting segments. 
   
   
       11 . The method according to  claim 10  wherein the interrupting segments have a slotted geometry. 
   
   
       12 . The method according to  claim 10  wherein the interrupting segments have a scalloped geometry. 
   
   
       13 . The method according to  claim 1  wherein decreasing the spacing between interrupting segments decreases the lengths of the string chips. 
   
   
       14 . The method according to  claim 1  wherein the step of machining the workpiece includes a plurality of machining passes, which remove the interrupting segments. 
   
   
       15 . A method of forming a surface finished workpiece for a vehicle from a metal sheet, wherein machining of the workpiece generates string chips having a desired maximum length for removal from the workpiece, the method comprising:
 forming the metal sheet into a blank having an edge with a contour, wherein the edge includes a plurality of interrupting segments spaced apart;   forming the blank into the workpiece;   machining at least a portion of the workpiece to within a surface tolerance, wherein the edge is a forming precursor of the portion and the geometry of the interrupting segments are depressively reshaped during forming, whereby the generated string chips break at the reshaped segments such that the lengths are less than the desired maximum; and   removing the string chips from the workpiece.   
   
   
       16 . The method of  claim 15  wherein forming includes stamping. 
   
   
       17 . The method of  claim 16  wherein the edge defines a substantially circular blank where the interrupting segments are substantially flat and the reshaped segments have a scalloped geometry. 
   
   
       18 . The method of  claim 17  wherein the metal sheet is low carbon steel and the blank has a diameter substantially between 10 and 20 inches, wherein the edge includes between 5 and 11 interrupting segments substantially between 1.0 and 1.5 inches in length that are equally spaced apart, whereby the generated string chips have lengths that are less than 2.0 inches. 
   
   
       19 . The method of  claim 15  wherein the step of machining the workpiece includes a plurality of machining passes, which remove the interrupting segments. 
   
   
       20 . A method of forming a surface finished workpiece for a vehicle from a metal sheet, wherein machining of the workpiece generates string chips having a desired maximum length for removal from the workpiece, the method comprising:
 stamping the metal sheet into a blank having an edge with a substantially curved contour, wherein the edge includes a plurality of substantially flat segments spaced apart;   stamping the blank into the workpiece;   welding a bladed structure to the workpiece;   machining at least a portion of the workpiece to within a surface tolerance, wherein the edge is a stamping precursor of the portion and the flat segments are reshaped during stamping into a scalloped geometry, whereby the generated string chips break at the reshaped segments such that the lengths are less than the desired maximum; and   removing the string chips from the workpiece.