Contoured air vent holes for dies

Abstract

The present disclosure describes a die for forming sheet metal. The die includes a die body, an outer surface, and a sheet metal facing surface. At least one passage extends through the die body to form an escape route, purging an amount of air trapped in-between the die and a sheet metal during a sheet metal operation. The passage includes an entry port, an exit port, and a bore that connects the entry port to the exit port. Each port has a transition area between its respective surface and the bore. The transition area is configured to be other than a right angle.

We claim: 
     
         1 . A die for forming sheet metal, the die comprising:
 a die body, an outer surface, and a sheet metal facing surface;   at least one passage extending through the die body to form an escape route to purge an amount of air trapped in-between the die and the sheet metal during a sheet metal operation, the passage having:
 an entry port on the sheet metal facing surface; 
 a bore, having a cross-sectional area, leading from the entry port; 
 an exit port on the outer surface and extending from the bore, each of the ports having a transition area between its respective surface and the bore, the transition area being other than a right angle. 
   
     
     
         2 . The die of  claim 1 , wherein the transition area is rounded. 
     
     
         3 . The die of  claim 1 , wherein the entry port and the exit port have a larger cross-sectional area than the bore's cross-sectional area. 
     
     
         4 . The die of  claim 3 , wherein the bore's cross-sectional area is configured to be circular. 
     
     
         5 . The die of  claim 1 , wherein the die is a draw die. 
     
     
         6 . The die of  claim 1 , wherein the die is at least one of the following:
 an upper die plate; and   a lower die plate.   
     
     
         7 . An air venting system in a die, the system comprising:
 at least one passage configured through the die to purge air trapped in-between the die and a sheet metal during a stamping operation, the passage defining:
 an entry port; 
 an exit port; 
 a bore, connecting the entry port to the exit port, the ports having a transition area between their respective surface and the bore, the transition area being other than a right angle. 
   
     
     
         8 . The system of  claim 7 , wherein the die is a draw die. 
     
     
         9 . The system of  claim 7 , wherein the die comprises at least one of the following:
 an upper die plate; and   a lower die plate.   
     
     
         10 . The system of  claim 7 , wherein the transition area is rounded. 
     
     
         11 . The system of  claim 7 , wherein the bore includes a circular cross-sectional area. 
     
     
         12 . The system of  claim 11 , wherein the entry port and the exit port have a larger cross-sectional area than the bore's cross-sectional area. 
     
     
         13 . A method of stamping sheet metal, the method comprising:
 reciprocating an upper die plate relative to a lower die plate, with at least one passage configured at least through the upper die plate, the passage forming an escape route for purging an amount of air trapped in-between the upper die plate and a sheet metal during a sheet metal operation, the passage having:
 an entry port; 
 an exit port; 
 a bore, having a cross-sectional area, connecting the entry port and the exit port. 
   
     
     
         14 . The method of  claim 13 , wherein the entry port and the exit port have a transition area between their respective surface and the bore, the transition area being other than a right angle. 
     
     
         15 . The method of  claim 14 , wherein the transition area is rounded. 
     
     
         16 . The method of  claim 13 , wherein the entry port and the exit port have a larger cross-sectional area than the bore's cross-sectional area. 
     
     
         17 . The method of  claim 16 , wherein the bore's cross-sectional area is circular.