Device and method for producing a hollow body from a workpiece in the form of a round blank

Abstract

The invention relates to a device for producing a hollow body from a workpiece in the shape of a circular blank, comprising a forming mandrel supported in a rotationally driven manner, a pressing element which is also supported on the machine bed in a rotating manner and in an axially displaceable manner relative to the forming mandrel for clamping the workpiece, and at least one forming roller which can be fed axially and/or radially to the forming mandrel. The provision is made that on the pressing element at least one forming die is arranged, into which the forming mandrel can be entered axially for forming the workpiece and that the forming die can be displaced axially with respect to the pressing element. The invention further relates to a method for producing a hollow body from a workpiece in the shape of a circular blank.

1 - 16 . (canceled) 
   
   
       17 . Device for producing a hollow body from a workpiece ( 1 ) in the shape of a circular blank, in particular a spinning and/or flow-forming machine, comprising
 a forming mandrel ( 11 ), which is supported in a rotationally driven manner about an axis of rotation ( 10 ),   a pressing element ( 18 ), which is supported about the axis of rotation ( 10 ) in a rotatable manner and in an axially displaceable manner relative to the forming mandrel ( 11 ) for clamping the workpiece ( 1 ), and   at least one forming roller ( 31 ), which can be fed axially and/or radially to the forming mandrel ( 11 ),   wherein on the pressing element ( 18 ) at least one forming die ( 40 ) is arranged, which can be displaced axially with respect to the pressing element ( 18 ) and can be moved axially relative to the forming mandrel ( 11 ) for forming the workpiece ( 1 ),   
     characterized in that
 the device is adapted to draw the workpiece ( 1 ) into the forming die ( 40 ) through axial movement of the forming die ( 40 ) and/or the forming mandrel ( 11 ) and to thereby form the said workpiece. 
 
   
   
       18 . Device according to  claim 17 , characterized in that the forming die ( 40 ) surrounds the pressing element ( 18 ) in a ring-like manner. 
   
   
       19 . Device according to  claim 17 , characterized in that on the forming mandrel ( 11 ) and/or on the pressing element ( 18 ) a stamp ( 13 ) is arranged, which can be moved frontally out of the forming mandrel ( 11 ) or the pressing element ( 18 ) for carrying out a forming operation. 
   
   
       20 . Device according to  claim 17 , characterized in that the forming die ( 40 ) has several die elements ( 41 ,  42 ) which can be moved axially relative to one another. 
   
   
       21 . Method for producing a hollow body from a workpiece ( 1 ) in the shape of a circular blank by means of a device comprising a forming mandrel ( 11 ), which is supported in a rotationally driven manner about an axis of rotation ( 10 ), a pressing element ( 18 ), which is supported about the axis of rotation ( 10 ) in a rotatable manner and in an axially displaceable manner relative to the forming mandrel ( 11 ) for clamping the workpiece ( 1 ), and comprising at least one forming die ( 40 ), which is arranged on the pressing element ( 18 ) and can be displaced axially with respect to the pressing element ( 18 ) and which can be moved axially relative to the forming mandrel ( 11 ) for forming the workpiece ( 1 ), in particular by means of a device according to any one of claims  1  to  4 , wherein
 an external portion ( 5 ) of the workpiece ( 1 ), which has been set into rotation, is formed, in particular projected formed, spun or flow-formed into a cylindrical shape ( 8 ) by feeding at least one forming roller ( 31 ),   
     characterized in that
 through the deep drawing or pressing in a central portion ( 4 ) of the workpiece ( 1 ) a base portion of the hollow body is formed, in which case the workpiece ( 1 ) is drawn into the forming die ( 40 ) through axial movement of the forming die ( 40 ) and/or the forming mandrel ( 11 ) and is thereby formed. 
 
   
   
       22 . Method according to  claim 21 , characterized in that the deep drawing or pressing of the central portion ( 4 ) and the folding-over of the external portion ( 5 ) are carried out in the same setting. 
   
   
       23 . Method according to  claim 21 , characterized in that during the deep drawing or pressing the external portion ( 5 ) is left unformed or is formed in a funnel-like manner. 
   
   
       24 . Method according to  claim 21 , characterized in that during the deep drawing or pressing the external portion ( 5 ) is supported in particular by means of at least one supporting roller ( 61 ,  62 ). 
   
   
       25 . Method according to  claim 21 , characterized in that the portion of the cylindrical shape ( 8 ) of the workpiece ( 1 ) is stretch-formed in at least one roller pass. 
   
   
       26 . Method according to  claim 25 , characterized in that during the stretch-forming a selected wall thickness distribution ( 28 ) is produced in an end portion ( 7 ) of the cylindrical shape ( 8 ), in particular by means of at least one multi-stage stretching roller ( 36 ) and/or through split adjustment. 
   
   
       27 . Method according to  claim 21 , characterized in that after the forming and in particular after stretch-forming the end portion of the cylindrical shape ( 8 ) is drawn-in by feeding at least one draw-in roller ( 38 ) and is closed, in particular by forming a container neck. 
   
   
       28 . Method according to  claim 21 , characterized in that during the deep drawing or pressing the wall thickness is changed in the central portion ( 4 ). 
   
   
       29 . Method according to  claim 21 , characterized in that on the workpiece ( 1 ) in the shape of a circular blank an opening with a hub ( 2 ) is formed. 
   
   
       30 . Method according to  claim 21 , characterized in that in particular after the deep drawing or pressing material is removed in the base portion by means of at least one roller and is formed to a flange. 
   
   
       31 . Method according to  claim 21 , characterized in that the workpiece ( 1 ) is heated prior to the deep drawing or pressing.