Flat die thread rolling machine and method for operating such a machine

Abstract

A flat die thread rolling machine ( 1 ) includes a stationarily arranged first tool part ( 2 ) and a second tool part ( 3 ) that moves relative thereto in an oscillatory manner. The two tool parts ( 2, 3 ) have a profiled surface which can be rolled into a workpiece ( 4 ) arranged between the tool parts ( 2, 3 ). The second tool part ( 3 ) is connected to a drive ( 5 ) that can cause the oscillatory motion of the second tool part ( 3 ). The drive ( 5 ) includes a servomotor ( 6 ) that is controlled by a machine controller ( 7 ).

What is claimed is: 
     
         1 . A flat die thread rolling machine ( 1 ), comprising:
 a thread rolling module ( 10 ), including
 a stationarily arranged first tool part ( 2 ); and 
 a second tool part ( 3 ) that moves relative to the first tool part ( 2 ) in an oscillatory motion, 
 wherein the first tool part ( 2 ) and the second tool part ( 3 ) have a profiled surface, 
 wherein the profiled surface is rolled into a workpiece ( 4 ) arranged between the first tool part ( 2 ) and the second tool part ( 3 ), 
 wherein the second tool part ( 3 ) is connected to a drive ( 5 ) that causes the oscillatory motion of the second tool part ( 3 ), 
 wherein the drive ( 5 ) comprises a servomotor ( 6 ), and 
 wherein the servomotor ( 6 ) is controlled by a machine controller ( 7 ). 
   
     
     
         2 . The flat die thread rolling machine ( 1 ) according to  claim 1 ,
 wherein the servomotor ( 6 ) directly or indirectly drives a threaded spindle ( 8 ),   wherein the threaded spindle ( 8 ) engages in a threaded nut, and   wherein the threaded nut is directly or indirectly connected to the second tool part ( 3 ).   
     
     
         3 . The flat die thread rolling machine ( 1 ) according to  claim 2 , further comprising
 a transmission ( 9 ) arranged between the servomotor ( 6 ) and the threaded spindle ( 8 ), whereby a rotary motion of the servomotor ( 6 ) is transmitted to the threaded spindle ( 8 ).   
     
     
         4 . The flat die thread rolling machine ( 1 ) according to  claim 3 ,
 wherein the transmission ( 9 ) is a belt drive transmission.   
     
     
         5 . The flat die thread rolling machine ( 1 ) according to  claim 1 , further comprising
 a further thread rolling module ( 11 ) having a stationarily arranged further first tool part ( 2 ) and a further second tool part ( 3 ) driven in an oscillatory manner by a further servomotor ( 6 ),   wherein the thread rolling module ( 10 ) and the further thread rolling module ( 11 ) are arranged at a specified distance (a) from each other.   
     
     
         6 . The flat die thread rolling machine ( 1 ) according to  claim 5 ,
 wherein the specified distance (a) is adjustable.   
     
     
         7 . The flat die thread rolling machine ( 1 ) according to  claim 1 ,
 wherein a first side area ( 12 ) of the machine is defined at a first end position of the second tool part ( 3 ) and   wherein a second side area ( 13 ) of the machine is defined at a second end position of the second tool part ( 3 ),   wherein a first handling element ( 14 ) for feeding the workpiece ( 4 ) as a raw workpiece is arranged in the first side area ( 12 ), and   wherein a second handling element ( 15 ) for removing the workpiece ( 4 ) as a rolled workpiece ( 4 ) is arranged in the second side area ( 13 ).   
     
     
         8 . The flat die thread rolling machine ( 1 ) according to  claim 7 ,
 wherein the oscillatory motion of the second tool part ( 3 ) defines a direction of motion (B), and   wherein the first handling element ( 14 ) and the second handling element ( 15 ) are displaceable in the direction of motion (B).   
     
     
         9 . A method, comprising:
 providing a flat die thread rolling machine ( 1 ), having
 a thread rolling module ( 10 ), including
 a stationarily arranged first tool part ( 2 ); and 
 a second tool part ( 3 ) that moves relative to the first tool part ( 2 ) in an oscillatory motion, 
 wherein the first tool part ( 2 ) and the second tool part ( 3 ) have a profiled surface, 
 wherein the profiled surface is rolled into a workpiece ( 4 ) arranged between the first tool part ( 2 ) and the second tool part ( 3 ), 
 wherein the second tool part ( 3 ) is connected to a drive ( 5 ) that causes the oscillatory motion of the second tool part ( 3 ), 
 wherein the drive ( 5 ) comprises a servomotor ( 6 ), and 
 wherein the servomotor ( 6 ) is controlled by a machine controller ( 7 ); and 
 
   specifying a defined motion profile for the servomotor ( 6 ) by the machine controller ( 7 ).   
     
     
         10 . The method according to  claim 9 ,
 wherein the defined motion profile causes the second tool part ( 3 ) to travel at a constant speed over at least a part of its path.   
     
     
         11 . The method according to  claim 10 ,
 wherein the second tool part ( 3 ) travels at the constant speed over at least 50% of its stroke length.   
     
     
         12 . The method according to  claim 9 ,
 wherein the defined motion profile causes the second tool part ( 3 ) to travel at a lower speed during a working stroke than during a return stroke of the second tool part ( 3 ).   
     
     
         13 . The method according to  claim 9 ,
 wherein the defined motion profile
 causes the second tool part ( 3 ) to travel at a constant working stroke speed over at least 50% of a working stroke length, and 
 causes the second tool part ( 3 ) to travel at a constant return stroke speed over at least 50% of a return stroke length, and 
   wherein the constant working stroke speed is lower than the constant return stroke speed.   
     
     
         14 . The method according to  claim 9 ,
 wherein the defined motion profile causes the second tool part ( 3 ) to travel at two different speeds during a working stroke of the second tool part ( 3 ), and   wherein the two different speeds include a lower speed followed by a higher speed.   
     
     
         15 . The method according to  claim 9 ,
 wherein the defined motion profile is a path-speed profile for the servomotor ( 6 ), and   wherein the path-speed profile is shifted by a specified displacement (Δx) in a path direction with respect to a nominal profile.