Method and tool set for producing a thread in at least two working steps

Abstract

In order to produce a thread in a workpiece, a preliminary thread can be produced in the workpiece in at least one first working step by removing material from the workpiece. The preliminary thread profile of the workpiece (from which material was removed) has two preliminary thread flanks and a preliminary thread root connecting the two preliminary thread flanks. In addition, a preliminary thread profile that has a final thread having a final thread profile is produced in at least one second working step by plastic pressing-in of the material of the workpiece at least in a section of at least one of the two preliminary thread flanks by a predetermined or predeterminable pressing-in volume.

1 . A method of producing a thread in a workpiece, comprising the steps: 
 a) producing a preliminary thread in the workpiece in at least one first working step by removing material from the workpiece, wherein a preliminary thread profile of the preliminary thread has two preliminary thread flanks and a preliminary thread root connecting the two preliminary thread flanks;    b) producing a final thread in at least one second working step by plastic pressing-in of the material of the workpiece at least in a section of at least one of the two preliminary thread flanks by a predetermined pressing-in volume.    
   
   
       2 . The method as claimed in  claim 1 , wherein, in the second working step, the material of the workpiece is essentially pressed in over the entire preliminary thread flank(s) by the predetermined pressing-in volume.  
   
   
       3 . The method as claimed in  claim 1 , wherein, in the second working step, the material of the workpiece is in each case pressed in in at least one first flank section of the preliminary thread flank(s) and remains essentially unchanged in at least one second flank section which adjoins the first flank section of the preliminary thread flank(s).  
   
   
       4 . The method as claimed in  claim 1 , wherein the final thread has a final thread profile with two final thread flanks and a final thread root connecting the two final thread flanks.  
   
   
       5 . The method as claimed in  claim 4 , wherein at least one final thread flank is formed completely by plastic pressing-in in the second working step.  
   
   
       6 . The method as claimed in  claim 4 , further comprising the steps: 
 forming at least one final thread flank in at least one first flank section by plastic pressing-in in the second working step; and    producing the at least one final thread flank in a second flank section adjoining the first flank section solely by the material removal in the first working step.    
   
   
       7 . The method as claimed in  claim 1 , further comprising the steps: 
 using a thread-forming profile in the second working step for the plastic pressing-in of the material of the workpiece;    wherein the thread-forming profile has two flanks and a root region connecting the two flanks.    
   
   
       8 . The method as claimed in  claim 1 , further comprising producing, in the first working step, a preliminary thread in which at least one of its preliminary flanks has an outer flank section and an inner flank section extending between the outer flank section and the preliminary thread root.  
   
   
       9 . The method as claimed in  claim 8 , further comprising producing, in the second working step, a final thread having a final thread profile, wherein one or both of: 
 a) at least one of the final thread's final flanks comprises an outer flank section of the preliminary thread profile and an inner flank section of the thread-forming profile; or    b) at least one of the final thread's final thread flanks comprises an outer flank section of the thread-forming profile and an inner flank section of the preliminary thread profile.    
   
   
       10 . The method as claimed in  claim 8 , further comprising: 
 a) using, in the second working step for the plastic pressing-in of the material of the workpiece, a thread-forming profile which has two flanks and a root region connecting the two flanks, at least one of these flanks of the thread-forming profile being subdivided into an outer flank section and an inner flank section; and    b) producing, in the second working step, a final thread having a final thread profile, wherein one or both of: 
 1) at least one of the final thread's final flanks comprises an outer flank section of the preliminary thread profile and an inner flank section of the thread-forming profile; or  
 2) at least one of the final thread's final thread flanks comprises an outer flank section of the thread-forming profile and an inner flank section of the preliminary thread profile.  
   
   
   
       11 . The method as claimed in  claim 1 , wherein the pressing-in volume, with respect to an identical profile length of the preliminary thread profile, is larger at the preliminary thread root than at the preliminary thread flank(s).  
   
   
       12 . The method as claimed in  claim 1 , wherein the pressing-in volume, with respect to an identical profile length of the preliminary thread profile, is smaller at the preliminary thread root than at the preliminary thread flank(s).  
   
   
       13 . The method as claimed in  claim 1 , wherein the preliminary thread flanks of the preliminary thread profile and the flanks of the thread-forming profile enclose the same opening angle relative to one another.  
   
   
       14 . A device for producing threads in workpieces, comprising: 
 a) at least one preliminary thread production region for the cutting production of a preliminary thread, the preliminary thread profile of which has two preliminary thread flanks and a preliminary thread root connecting the two preliminary thread flanks; and    b) at least one thread-forming region for re-forming the preliminary thread by plastic pressing-in of the material of the workpiece at least in a section of the preliminary thread flanks by a predetermined pressing-in volume.    
   
   
       15 . The device as claimed in  claim 14 , wherein the at least one preliminary thread production region and the at least one thread-forming region are each formed on an associated tool.  
   
   
       16 . The device as claimed in  claim 14 , wherein the at least one preliminary thread production region and the at least one thread-forming region are formed on a common combined tool.  
   
   
       17 . The device as claimed in  claim 14 , wherein: 
 a thread-forming profile of the thread-forming region has two flanks and a thread root region connecting the two flanks; and    at least sections of the flanks of the thread-forming profile have larger dimensions, or are at a larger distance apart, than one of: 
 the preliminary thread flanks; or  
 the flanks of a thread-cutting profile of the preliminary thread production region.  
   
   
   
       18 . The device as claimed in  claim 14 , the device being configured for carrying out a method as claimed in one of  1 , wherein the final thread resulting from the preliminary thread is re-formed by the thread-forming region.