Method of reducing wrinkles in pressed sheet metal components

Abstract

A method of forming a sheet metal component includes the steps of initially forming a profiled blank from a metal sheet and then identifying on a surface of the blank, one or more wrinkle lines across which a buckling stress exceeds a critical buckling stress limit. Then at least one slot is cut into in the profiled blank, with the or each slot extending entirely through a thickness of the profiled blank and being coincident with one of the wrinkle lines, and a hole is cut at one end of the slot with the hole having a diameter greater than a lateral width of the slot. The profiled blank is then processed in a pressing operation to form a shaped blank with one or more welding operations being carried out on the shaped blank along each slot to produce a finished sheet metal component.

1 . A method of forming a sheet metal component, the method comprising the steps of:
 (i) forming a profiled blank from a metal sheet;   (ii) identifying on a surface of the blank, one or more wrinkle lines across which a buckling stress exceeds a critical buckling stress limit;   (iii) cutting at least one slot in the profiled blank, the or each slot extending entirely through a thickness of the profiled blank, the or each slot being coincident with a respective one of the or each wrinkle lines;   (iv) processing the profiled blank in a pressing operation to form a shaped blank; and   (v) performing one or more welding operations on the shaped blank along the or each slot to thereby produce a finished sheet metal component.   
     
     
         2 . The method as claimed in  claim 1 , wherein step (iii) comprises the additional step of cutting a hole at one end of the slot, the hole having a diameter greater than a lateral width of the slot. 
     
     
         3 . The method as claimed in  claim 1 , wherein step (iii) comprises the additional step of:
 (iii)′ cutting a hole at each end of the slot, each hole having a diameter greater than a lateral width of the slot.   
     
     
         4 . The method as claimed in  claim 1 , wherein each slot has a constant lateral width along the length of the slot. 
     
     
         5 . The method as claimed in  claim 1 , wherein each slot has a lateral width that tapers in a direction extending from a first end of the slot towards an opposite second end of the slot. 
     
     
         6 . The method as claimed in  claim 1 , wherein step (v) comprises the step of:
 (v)′ performing one or more welding operations on the shaped blank along the entire length of the or each slot to thereby produce a finished sheet metal component.   
     
     
         7 . The method as claimed in  claim 2 , wherein each slot has a constant lateral width along the length of the slot. 
     
     
         8 . The method as claimed in  claim 3 , wherein each slot has a constant lateral width along the length of the slot. 
     
     
         9 . The method as claimed in  claim 2 , wherein each slot has a lateral width that tapers in a direction extending from a first end of the slot towards an opposite second end of the slot. 
     
     
         10 . The method as claimed in  claim 3 , wherein each slot has a lateral width that tapers in a direction extending from a first end of the slot towards an opposite second end of the slot. 
     
     
         11 . The method as claimed in  claim 2 , wherein step (v) comprises the step of:
 (v)′ performing one or more welding operations on the shaped blank along the entire length of the or each slot to thereby produce a finished sheet metal component.   
     
     
         12 . The method as claimed in  claim 3 , wherein step (v) comprises the step of:
 (v)′ performing one or more welding operations on the shaped blank along the entire length of the or each slot to thereby produce a finished sheet metal component.   
     
     
         13 . The method as claimed in  claim 4 , wherein step (v) comprises the step of:
 (v)′ performing one or more welding operations on the shaped blank along the entire length of the or each slot to thereby produce a finished sheet metal component.   
     
     
         14 . The method as claimed in  claim 5 , wherein step (v) comprises the step of:
 (v)′ performing one or more welding operations on the shaped blank along the entire length of the or each slot to thereby produce a finished sheet metal component.   
     
     
         15 . The method as claimed in  claim 7 , wherein step (v) comprises the step of:
 (v)′ performing one or more welding operations on the shaped blank along the entire length of the or each slot to thereby produce a finished sheet metal component.   
     
     
         16 . The method as claimed in  claim 8 , wherein step (v) comprises the step of:
 (v)′ performing one or more welding operations on the shaped blank along the entire length of the or each slot to thereby produce a finished sheet metal component.   
     
     
         17 . The method as claimed in  claim 9 , wherein step (v) comprises the step of:
 (v)′ performing one or more welding operations on the shaped blank along the entire length of the or each slot to thereby produce a finished sheet metal component.   
     
     
         18 . The method as claimed in  claim 10 , wherein step (v) comprises the step of:
 (v)′ performing one or more welding operations on the shaped blank along the entire length of the or each slot to thereby produce a finished sheet metal component.