Process and device for the manufacture of polygonal tubes

Abstract

This invention concerns a device for the manufacture of polygonal tubes, with a base frame ( 2 ) and an upright assembly wall ( 10 ) that is equipped with a rotating mandrel ( 7 ) having a polygonal cross-section and a drive system ( 6 ); a corrugated strip of foil ( 60 ) fed by feed rolls ( 29 ) is wound onto this mandrel; on both edges, the strip of foil ( 60 ) has a pre-formed fold; during the winding process, adjacent edges with such pre-formed folds can be inserted in each other and closed to form a fold; in the assembly wall ( 10 ), shafts ( 16 ) that are concentric to the axis of rotation of the mandrel ( 7 ) carry arms ( 20 ) with rolling tools ( 30 ) directed at the mandrel ( 7 ). In the device proposed by the invention, at least one shaping roll ( 42 ) is provided that is located outside the mandrel ( 7 ) in axial direction of the tube to be manufactured.

1  Device for the manufacture of polygonal tubes, with a base frame ( 2 ) and an upright assembly wall ( 10 ) that is equipped with a rotating mandrel ( 7 ) having a polygonal cross-section and a drive system ( 6 ); a corrugated strip of foil ( 60 ) fed by feed rolls ( 29 ) is wound onto this mandrel; on both edges, the strip of foil ( 60 ) has a pre-formed fold; during the winding process, adjacent edges with such pre-formed folds can be inserted in each other and closed to form a fold; in the assembly wall ( 10 ), shafts ( 16 ) that are concentric to the axis of rotation of the mandrel ( 7 ) carry arms ( 20 ) with rolling tools ( 30 ) directed at the mandrel ( 7 ), characterized by the feature that at least one shaping roll ( 42 ) is provided that is located outside the mandrel ( 7 ) in axial direction of the tube to be manufactured.  
     
     
         2  Device according to  claim 1 , characterized by the feature that this includes a first shaping roll ( 41 ) and a second shaping roll ( 42 ), with the first shaping roll ( 41 ) located on the outside of the tube, and the second shaping roll ( 42 ) located on the inside of the tube.  
     
     
         3  Device according to  claim 3 , characterized by the feature that the surfaces of the first and second shaping roll ( 41 ,  42 ) approximately face each other.  
     
     
         4  Device according to one of the claims  2  or  3 , characterized by the feature that the first and second shaping roll ( 41 ,  42 ) each consists of individual disks, and that the disks are axially spaced with reference to the axis of rotation of the shaping rolls ( 41 , 42 ).  
     
     
         5  Device according to  claim 4 , characterized by the feature that the first and the second shaping roll ( 41 ,  42 ) mesh with each other in such way that some disks of both shaping rolls partially overlap each other in axial direction.  
     
     
         6  Device according to one of the claims  1 - 5 , characterized by the feature that the first and/or the second shaping roll are mounted on at least one swiveling arm ( 20 ,  44 ).  
     
     
         7  Device according to  claim 6 , characterized by the feature that the first shaping roll is mounted on a first arm ( 20 ) and the second shaping roll is mounted on a second arm ( 44 ).  
     
     
         8  Device according to  claim 7 , characterized by the feature that the first arm ( 20 ) and the second arm ( 44 ) are coupled kinematically.  
     
     
         9  Device according to one of the  claims 2  to  8 , characterized by the feature that the first and the second shaping roll ( 41 ,  42 ) can be moved axially with reference to the circumferential line of the mandrel.  
     
     
         10  Device according to one of the  claims 8  to  9 , characterized by the feature that the first arm ( 20 ) and the second arm ( 44 ) are coupled hydraulically.  
     
     
         11  Device according to one of the  claims 8  to  9 , characterized by the feature that the first arm ( 20 ) and the second arm ( 44 ) are coupled pneumatically.  
     
     
         12  Device according to one of the  claims 8  to  9 , characterized by the feature that the first arm ( 20 ) and the second arm ( 44 ) are coupled by means of a spring.  
     
     
         12  Device according to one of the  claims 1  to  12 , characterized by the feature that at least one of the shaping rolls ( 41 ,  42 ) engages the foil strip ( 60 ) in such way that during the closing or after the closing of the fold this fold is located in radial direction of the tube.  
     
     
         13  Process for manufacturing polygonal hollow sections from a corrugated web of thin material ( 60 ) that is wound helically, and with overlapping of the edges for the purpose of forming a fold, onto a polygonal mandrel ( 7 ) under the pressure of rolling tools ( 30 ) that are supported, with the ability to move in an approximately radial direction relative to the mandrel ( 7 ) on swiveling arms ( 20 ), pressing the web of material ( 60 ) against the outer surface of the mandrel ( 7 ); on both edges, the web of material ( 60 ) has a pre-formed fold that is closed during the winding process by means of at least one shaping roll, characterized by the feature that the fold is formed in such way that it runs essentially radially relative to the center axis of the tube.  
     
     
         14  Hollow section made from a web of corrugated thin material that was wound helically, and with overlapping of the edges for the purpose of forming a fold, onto a polygonal mandrel, characterized by the feature that the fold is approximately radial relative to the center axis of the hollow section.