Vertical type surface grinding machine

Abstract

A vertical type surface grinding machine includes a column arranged over an index table. The column includes, in a plan view, a lateral side portion extending along a direction of arrangement of first and second positions, and a vertical side portion extending perpendicularly to the lateral side portion. The column is supported from below by both ends of the lateral side portion and at least one end of the vertical side portion. Each of first and second grinding mechanisms is supported by the lateral side portion and the vertical side portion while arrange like a bridge between the lateral side portion and the vertical side portion. Each of feeding mechanisms of the first and second grinding mechanisms is located at a corner at which the lateral side portion and the vertical side portion intersect.

What is claimed is: 
     
         1 . A vertical type surface grinding machine configured to grind a surface of a workpiece, the machine comprising:
 an index table having at least two chucks on each of which the workpiece is mounted, the index table having a central axis extending in an upward/downward direction and being configured to move the two chucks rotationally between a first position and a second position arranged in a circumferential direction around the central axis;   a column arranged over the index table;   a first grinding wheel mechanism supported by the column and configured to machine the workpiece mounted on one of the chucks located at the first position; and   a second grinding wheel mechanism supported by the column and configured to machine the workpiece mounted on another one of the chucks located at the second position,   the column including, in a plan view along the central axis:   a lateral side portion extending along a direction of arrangement of the first and second positions; and   a vertical side portion extending from a central portion of the lateral side portion perpendicularly to the lateral side portion,   the column being supported from below by both ends of the lateral side portion and at least one end of the vertical side portion,   the first and second grinding wheel mechanisms each including:   a spindle driven rotationally by a motor so as to rotate around a predetermined rotation axis; and   a feeding mechanism configured to move the spindle in an axial direction along the rotation axis,   each of the first and second grinding wheel mechanisms being supported by the lateral side portion and the vertical side portion while arranged like a bridge between the lateral side portion and the vertical side portion,   each of the feeding mechanisms of the first and second grinding wheel mechanisms being located at a corner at which the lateral side portion and the vertical side portion intersect.   
     
     
         2 . The vertical type surface grinding machine of  claim 1 , wherein
 the lateral side portion is supported from below by first and second supporting portions located at both ends of the lateral side portion in the direction of arrangement,   the vertical side portion is supported from below by a third supporting portion located at one end of the vertical side portion opposite to the lateral side portion,   the spindle of the first grinding wheel mechanism is located at a central portion of a straight line connecting the first supporting portion and the third supporting portion in the plan view,   the spindle of the second grinding wheel mechanism is located at a central portion of a straight line connecting the second supporting portion and the third supporting portion in the plan view, and   each of the feeding mechanisms of the first and second grinding wheel mechanisms is located inside a triangle connecting the first supporting portion, the second supporting portion, and the third supporting portion in the plan view.   
     
     
         3 . The vertical type surface grinding machine of  claim 2 , wherein
 the first and second grinding wheel mechanisms each include   a pair of linear guides configured to support the spindle on the column and arranged along a straight line passing through the rotation axis of the spindle in the plan view,   one of the pair of linear guides is supported by the lateral side portion, and   another one of the pair of linear guides is supported by the vertical side portion.   
     
     
         4 . The vertical type surface grinding machine of  claim 2 , wherein
 a pedestal supporting the index table includes, in the plan view:   a first chamfer cut along the straight line connecting the first supporting portion and the third supporting portion;   a second chamfer cut along the straight line connecting the second supporting portion and the third supporting portion; and   an operation surface located between the first chamfer and the second chamfer and extending along the lateral side portion.   
     
     
         5 . The vertical type surface grinding machine of  claim 1 , wherein
 the index table has three chucks on each of which the workpiece is mounted, the index table being configured to move the three chucks rotationally among the first position and the second position arranged in the circumferential direction and a third position at which the workpiece is replaced,   the lateral side portion extends in between the third position and the first and second positions in the plan view, and   the vertical side portion extends in a direction away from the third position in the plan view.