Workpieces processing machine and method for automatically controlling the dimensions of workpieces in such a machine

Abstract

A workpiece processing machine comprising a handler for loading a working station of the machine with workpieces for processing. The machine includes a laser detection cell and a computation apparatus configured to compute a first dimension of the workpiece based upon a position of the handler when the workpiece crosses a laser beam of the laser detection cell while being moved by the handler in a first direction. The method automatically controls dimensions of workpieces processed in a working station thereof. The method includes steps of: a) picking a workpiece in an inlet station, b) moving the workpiece using a handler in a direction towards a laser beam of the laser detection cell, c) detecting the position of the handler when the workpiece crosses the laser beam along the direction and d) computing a dimension of the workpiece on the basis of the position of the handler (in step c).

1 . A workpiece processing machine comprising a handling tool for loading a working station of the machine with workpieces to be processed, the machine comprising:
 a laser detection cell; and   a computation apparatus configured to compute at least a first dimension of a workpiece on the basis of a position of the handling tool when the workpiece crosses a laser beam of the laser detection cell while being moved by the handling tool in a first direction.   
     
     
         2 . The machine according to  claim 1 , wherein the computation apparatus is configured to additionally compute a second dimension of the workpiece on the basis of the position of the handling tool when the workpiece crosses the laser beam of the laser detection cell while being moved by the handling tool in a second direction. 
     
     
         3 . The machine according to  claim 1 , wherein the handling tool is mounted on a multi-axis robot, preferably a six-axis robot. 
     
     
         4 . The machine according to  claim 1 , wherein the handling tool is mounted on a six-axis robot. 
     
     
         5 . The machine according to  claim 1 , wherein the handling tool is a clamp provided with a gripping element for gripping the workpiece. 
     
     
         6 . The machine according to  claim 1 , wherein the machine is a grinding machine for bearing rings and the dimension computed by the computing apparatus is one of a diameter or an axial length of a bearing ring. 
     
     
         7 . A method for automatically controlling some dimensions of workpieces to be processed in a working station of a machine, the method comprising steps of:
 a) picking a workpiece in an inlet station of the machine;   b) moving the workpiece with a handling tool, in a first direction towards a laser beam of a fixed laser detection cell;   c) detecting the position of the handling tool when the workpiece crosses the laser beam along the first direction; and   d) computing a dimension of the workpiece on the basis of the position of the handling tool detected at step c).   
     
     
         8 . The method according to  claim 7 , wherein the computation of step d) is based on a distance between the laser beam and a part of the handling tool in contact with the workpiece . 
     
     
         9 . The method according to  claim 8 , wherein a diameter of the bearing ring is computed at step d) on the basis of the distance between the laser beam and the part of the handling tool in contact with the workpiece. 
     
     
         10 . The method according to  claim 9 , wherein an axial length of the bearing ring is computed at step d) as the distance between the two positions is respectively detected at steps c) and f). 
     
     
         11 . The method according to  claim 7 , further comprising steps implemented prior to step d) and consisting of:
 e) moving the workpiece with the handling tool in a second direction towards the laser beam;   f) detecting the position of the handling tool when the workpiece crosses the laser beam along the second direction; and   in that the computation of step d) is based on a distance between the positions of the handling tool respectively detected at steps c) and f).   
     
     
         12 . The method according to  claim 11 , wherein several diameters of the bearing ring are computed on the basis of several positions of the handling tool when the bearing ring crosses the laser beam along different directions. 
     
     
         13 . The method according to  claim 7 , wherein the method is implemented on a grinding machine, the workpieces are bearing rings and the dimension computed at step d) is one of a diameter or an axial length of a bearing ring. 
     
     
         14 . The method according to  claim 7 , wherein the position of the handling tool is detected by sensors coupled to driving actuators of the handling tool.