Method for producing a peripherally closed hollow profield element

Abstract

The invention relates to a method for producing a peripherally closed hollow profiled element by means of internal high-pressure forming, a hollow elongated blank ( 5 ) being inserted into an internal high-pressure forming tool ( 1 ), and the blank ( 5 ) located completely inside the forming tool ( 1 ) after the insertion being compressed in a region lying between its ends ( 9, 10 ) during the closing operation of the forming tool ( 1 ), after which the compressed blank ( 5 ) is expanded into the final shape of the hollow profiled element by means of fluidic internal high pressure. In order to permit reliable production of the hollow profiled element even during pronounced compression deformations of the blank ( 5 ) of the hollow profiled element, which are produced during the closing of the forming tool ( 1 ), it is proposed that the ends ( 9, 10 ) of the blank ( 5 ) be trimmed before the compression operation, with a respective beveled front face ( 12, 13 ) being formed, and that the trimming contour of the ends ( 9, 10 ) and the beveling angle (α) be selected in such a way that the ends ( 9, 10 ) are deformed by means of the compression operation in such a way that their front faces ( 12, 13 ) have an essentially plane form and assume a position which is as perpendicular as possible to the longitudinal extent of the blank ( 5 ).

1 . A method for producing a peripherally closed hollow profiled element by means of internal high-pressure forming, comprising: 
 inserting a hollow elongated blank into an internal high-pressure forming tool, the blank located completely inside the forming tool after the insertion being compressed in a region lying between its ends during the closing operation of the forming tool, after which the compressed blank is expanded into the final shape of the hollow profiled element by means of fluidic internal high pressure,    wherein the ends ( 9 ,  10 ) of the blank ( 5 ) are trimmed before the compression operation, with a respective beveled front face ( 12 ,  13 ) being formed, and    wherein the trimming contour of the ends ( 9 ,  10 ) and the beveling angle (a) are selected in such a way that the ends ( 9 ,  10 ) are deformed by means of the compression operation in such a way that their front faces ( 12 ,  13 ) have an essentially plane form and assume a position which is as perpendicular as possible to the longitudinal extent of the blank ( 5 ).    
     
     
         2 . The method as claimed in  claim 1 , wherein the trimming is effected in such a way that the front faces ( 12 ,  13 ) of the ends ( 9 ,  10 ) are beveled relative to the center axis ( 18 ) lying in the compression direction and running transversely to the longitudinal axis ( 11 ) of the blank ( 5 ).  
     
     
         3 . The method as claimed in  claim 1 , wherein the blank ends ( 9 ,  10 ) are trimmed in such a way that their front faces ( 12 ,  13 ) remain arranged parallel to one another.  
     
     
         4 . The method as claimed in  claim 1 , wherein the beveling angle (α) lies within a range of from 6° to 10°.  
     
     
         5 . The method as claimed in  claim 1 , wherein the end deformation occurring due to the subsequent compression operation is determined by a computer simulation before the trimming of the ends ( 9 ,  10 ) and then a trimming contour and a beveling angle (α) of the trimming to be effected is calculated therefrom for compensating for the deformation.  
     
     
         6 . The method as claimed in  claim 1 , wherein the trimming of the ends ( 9 ,  10 ) is effected two-dimensionally.  
     
     
         7 . The method as claimed in  claim 1 , wherein the trimming of the ends ( 9 ,  10 ) is effected by a three-dimensional contour cut.  
     
     
         8 . The method as claimed in  claim 1 , wherein the beveling angle (α) is 8°.