Method for forming a groove and flow-forming machine

Abstract

The invention relates to a method and a flow-forming machine for inserting a groove in a cylindrical, thin workpiece. The workpiece is rotated relative to at least one spinning roller. The spinning roller is provided with a profile corresponding to the groove to be shaped. The spinning roller is radially infed to the workpiece and the groove is shaped. A particularly precise forming of the groove is brought about in that simultaneously with the radial infeeding of the spinning roller and the shaping of the groove, the workpiece is axially upset by means of at least one punch.

1 . Method for forming a groove into a thin wall of a workpiece, in which 
 the workpiece is axially fixed,    the workpiece is rotated relative to at least one spinning roller,    for shaping a groove, the spinning roller is radially infed to a working area of the workpiece and    with the radial infeeding of the spinning roller and the shaping of the groove, the workpiece is axially upset,     wherein 
 a spinning roller with a convex profile and support areas laterally adjacent thereto is infed and  
 the groove with its corner areas is formed in geometrically accurate manner corresponding to the convex profile and the laterally adjacent support areas of the spinning roller.  
   
     
     
         2 . Method according to  claim 1 , wherein the spinning roller is located outside the workpiece and is radially inwardly infed to the workpiece for shaping an outer groove.  
     
     
         3 . Method according to  claim 1 , wherein the spinning roller is located within the workpiece and is radially outwardly infed to the workpiece for shaping an inner groove.  
     
     
         4 . Method according to  claim 1 , wherein the workpiece is axially fixed between two movable spindle elements as punches, both of which are axially moved during upsetting.  
     
     
         5 . Method according to  claim 1 , wherein the workpiece is axially fixed between a movable spindle element and a stationary spindle element and that during axial upsetting the movable spindle element and the spinning roller are moved axially to the stationary spindle element, the movable spindle element being moved at a higher axial velocity than the spinning roller.  
     
     
         6 . Method according to  claim 1 , wherein during the axial upsetting of the workpiece the punch is moved in a clearly defined manner and in the vicinity of the groove a wall thickness of the workpiece remains virtually unchanged or is increased in planned manner.  
     
     
         7 . Method according to  claim 1 , wherein the movement of the punch is carried out as a function of the radial infeeding of the spinning roller in accordance with a predetermined control program.  
     
     
         8 . Method according to  claim 1 , wherein the groove is formed between the spinning roller on one side and an opposite roller on the other side.  
     
     
         9 . Method according to  claim 1 , wherein during the shaping of the groove, the workpiece is supported along its axial length on the outer circumference and/or inner circumference.  
     
     
         10 . Method according to  claim 1 , wherein on ending the radial infeed of the spinning roller for shaping the corner areas a certain axial upsetting is performed.  
     
     
         11 . Flow-forming machine, particularly for performing a method according to one of the  claims 1  to  10 , having 
 two spindle elements between which can be fixed a workpiece,  
 at least one radially adjustable spinning roller,  
 a rotary drive for rotating the workpiece relative to the spinning roller  
 at least one axial drive for the axial movement of at least one spindle element for upsetting and  
 control means with which, for a clearly defined shaping of a groove, at least one spindle element is moved axially and relatively towards the spinning roller,  
  wherein 
 the spinning roller has a convex profile and support areas laterally adjacent thereto and which are constructed in accordance with the groove to be formed and the corner areas thereof.  
 
 
     
     
         12 . Flow-forming machine according to  claim 11 , wherein both spindle elements, as punches, have a radial stop face and a circumferentially directed stop face.  
     
     
         13 . Flow-forming machine according to  claim 11 , wherein a holding device and/or an ejector is provided on at least one of the spindle elements.  
     
     
         14 . Flow-forming machine according to  claim 11 , wherein both spindle elements are displaceably mounted and in each case have a separate drive.  
     
     
         15 . Flow-forming machine according to  claim 11 , wherein one spindle element is displaceably mounted and driven, whereas the other spindle element is stationary and that the spinning roller is axially movable.  
     
     
         16 . Flow-forming machine according to  claim 11 , wherein the radial and/or axial infeeding of the spinning roller is controlled as a function of the punch movement.