Process for producing hollow metal articles

Abstract

The invention concerns a process for producing a metallic hollow body ( 1 ), in which a hollow cast part ( 1 ′) is produced by metal casting, in which the cast part ( 1 ′) is deformed by means of internal high pressure deformation in the hollow body ( 1 ). In order to improve the quality of the hollow body ( 1 ), the cast part ( 1 ′) is so produced, that it has a wall thickness distribution supporting or simplifying the internal high pressure deformation.

1 . A process for producing a metallic hollow body ( 1 ), including the steps 
 producing a hollow cast part ( 1 ′) by metal casting, such that the cast part ( 1 ′) includes a deformation area ( 2 ) which is to be subsequently deformed by internal high pressure deformation, and has at least one thereto adjacent reservoir zone ( 7 ), which has a thicker wall thickness relative to the deformation area ( 2 ) than the adjacent neighboring area ( 8 ) of the cast part ( 1 ′), so that the distribution of the wall thickness supports or simplifies an internal high pressure deformation,    deforming the cast part ( 1 ′) by internal high pressure deformation to form the hollow body ( 1 ).    
     
     
         2 . A process according to  claim 1 , wherein a cast part ( 1 ′) is produced, 
 in which the respective deformation area ( 2 ) is surrounded by the reservoir zone ( 7 ) or by multiple such reservoirs zones ( 7 ), and/or    in which the respective reservoir zones ( 7 ) are formed by respective bulges protruding relative to an adjacent area ( 8 ), and/or    in which the respective reservoir zone ( 7 ) exhibits an enlarged wall thickness only towards inwards with reference to the mold core.    
     
     
         3 . A process according to  claim 1 , wherein the cast part ( 1 ′) and the internal high pressure deformation area are so designed, 
 that in the hollow body ( 1 ) the wall thickness in the deformation area ( 2 ) and in the respective reservoir zone ( 7 ) are the same following the internal high pressure deformation, or    that after the internal high pressure deformation the hollow body ( 1 ) exhibits approximately the same wall thickness in the deformation area ( 2 ) and in the respective reservoir zone ( 7 ), or    that after the internal high pressure deformation the hollow body ( 1 ) exhibits the same wall thickness in respective adjacent areas ( 2 ) and in the respective reservoir zone ( 7 ), or    that prior to the internal high pressure deformation the wall thickness in the reservoir zone ( 7 ) is at least 50% larger then in the deformation area ( 2 ) and/or in the adjacent area ( 8 ), or    that the wall thickness in the reservoir zone ( 7 ) after the internal high pressure deformation is maximally 10% larger or smaller than in the deformation area ( 2 ) and/or then in the adjacent area ( 8 ).    
     
     
         4 . A process according to  claim 1  comprising forming on said cast part ( 1 ′), adjacent to a deformation area ( 2 ) in which the cast part ( 1 ′) is deformed during internal high pressure deformation, at least one anchor ( 9 ), which is located on an outer contour ( 1 ) of the cast part ( 1 ′), 
 introducing said cast part ( 1 ′) into a mold having a matrix or die such that said anchor is in mating engagement with a recess ( 4 ) adapted to receive said anchor zone, and    subjecting said cast part ( 1 ′) to internal high pressure deformation, whereby during internal high pressure deformation said anchor ( 9 ) cooperates with said matrix or die ( 4 ) of an internal high pressure deformation tool ( 3 ) for fixing the cast part ( 1 ′) in the matrix or die ( 4 ).    
     
     
         5 . A process according to  claim 4 , wherein the cast part ( 1 ′) is produced, 
 in which the respective deformation area ( 2 ) is surrounded by the anchor zone ( 9 ) or multiple such anchor zones ( 9 ), or    in which the respective anchor zones ( 9 ) relative to an adjacent neighboring area ( 8 ) of the cast part ( 1 ′) exhibit a greater wall thickness, or    in which, in the respective anchor zones ( 9 ), the enlarged wall thickness is directed only towards outwards, or    in which the respective anchor zones ( 9 ) are formed by a bulge projecting towards outwards from the respective neighboring area ( 8 ), or    in which the respective anchor zones ( 9 ) are formed by a recess formed in the outer contour ( 10 ).    
     
     
         6 . A process according to  claim 5 , wherein the internal high pressure deformation is continued only so long, that the respective anchor zone ( 9 ) continues to remain on the hollow body ( 1 ) even after the internal high pressure deformation.  
     
     
         7 . A process according to  claim 2 , wherein a cast part ( 1 ′) is produced, which has, next to a deformation area ( 2 ), at least one reservoir zone ( 7 ) directed inwards and at least one anchor zone ( 9 ) directed outwards.  
     
     
         8 . A process according to  claim 1 , wherein a cast part is produced, 
 in which the cast part ( 1 ′) is produced completely under-sized or undersized relative to the hollow body ( 1 ) or,    in which the outer dimensioning, relative to the outer contour ( 1 ) and/or relative to the inner contour ( 12 ) of the hollow body ( 1 ), is at least 5%.    
     
     
         9 . A process according to  claim 1 , wherein 
 the cast part ( 1 ′) is produced using a core ( 18 ), which is positioned in a hollow space ( 18 ) of a cast mold ( 13 ) using metallic core supports ( 19 ), and/or    an outlet opening of the cast part ( 1 ′) is provided, through which a core ( 18 ) or a core material can be removed out of the cast part ( 1 ′) subsequent to casting, said opening for acting upon the cast part ( 1 ′) with internal high pressure during internal high pressure deformation, and/or    at least one of the core supports ( 19 ) remains in the finished hollow body ( 1 ) as a securing element, and/or    as the core support ( 19 ), a securing element is employed, which is a part of the finished hollow body ( 1 ).    
     
     
         10 . A process according to  claim 1 , wherein 
 the cast part ( 1 ′) is a thin-wall cast part, and/or    that the cast part ( 1 ′) is a steel cast part or a light metal cast part, in particular, an aluminum cast part or a magnesium cast part.    
     
     
         11 . A process according to  claim 1 , wherein 
 the internal high pressure deformation is carried out as a thermal internal high pressure deformation, and/or    the internal high pressure deformation is coupled with a trimming process for trimming at least a part of the hollow body ( 1 ), and/or    the internal high pressure deformation is coupled with a stamping process for removing at least one wall area out of the wall of the hollow body ( 1 ).