Roller hemming apparatus and roller hemming method

Abstract

A roller hemming apparatus includes: a cylindrical roller supported rotatably on a main body; a first position adjusting mechanism for adjusting a first position of the roller in a direction which is perpendicular to a rotating axis direction thereof; a second position adjusting mechanism for adjusting a second position of the roller in the rotating axis direction; and a control unit for controlling the first and second position adjusting mechanisms. The control unit adjusts the first position by controlling the first position adjusting mechanism to abut the roller with a third position which is apart from a bending point of the flange, and the control unit adjusts the second position by detecting a load acting on the roller in an axial direction thereof as a drive load, calculating a difference between the drive load and a given master load, and controlling the second position adjusting mechanism according to the difference.

1 . A roller hemming apparatus for hemming a flange formed on a workpiece, comprising:
 a main body;   a cylindrical roller supported rotatably on the main body;   a first position adjusting mechanism for adjusting a first position of the roller with respect to a direction which is perpendicular to a rotating axis direction of the roller;   a second position adjusting mechanism for adjusting a second position of the roller with respect to the rotating axis direction; and   a control unit for controlling the first position adjusting mechanism and the second position adjusting mechanism,   wherein the control unit adjusts the first position of the roller by controlling the first position adjusting mechanism to bring the roller into abutment with a third position which is spaced by a given distance apart from a bending point of the flange, and   wherein the control unit adjusts the second position of the roller by detecting a load acting on the roller in an axial direction of the roller as a drive load, calculating a difference between the drive load and a given master load, and controlling the second position adjusting mechanism according to the difference.   
     
     
         2 . The roller hemming apparatus according to  claim 1 , wherein
 when the drive load is larger than the master load, the control unit controls the second position adjusting mechanism so as to position the roller in a direction in which the flange is bent largely.   
     
     
         3 . A roller hemming method for hemming a flange formed on a workpiece, comprising:
 providing a roller hemming apparatus including: a main body; a cylindrical roller supported rotatably on the main body; a first position adjusting mechanism for adjusting a first position of the roller with respect to a direction which is perpendicular to a rotating axis direction of the roller; and a second position adjusting mechanism for adjusting a second position of the roller with respect to the rotating axis direction;   adjusting the first position of the roller by controlling the first position adjusting mechanism to bring the roller into abutment with a third position which is spaced by a given distance apart from a bending point of the flange;   detecting a load acting on the roller in an axial direction of the roller as a drive load;   calculating a difference between the drive load and a given master load; and   adjusting the second position of the roller by controlling the second position adjusting mechanism according to the difference.   
     
     
         4 . The roller hemming method according to  claim 3 , wherein
 when the drive load is larger than the master load, the roller is positioned in a direction in which the flange is bent largely by controlling the second position adjusting mechanism.