Surface grinding method for workpiece and surface grinder

Abstract

[Problem] To enable efficiently grinding a workpiece of a hard brittle material, a difficult-to-cut material, or others at a moderate high load. [Solution Means] When surface-grinding a workpiece by a grinding wheel, a grinding load is monitored while the grinding wheel is reduced in cut-in speed when the grinding load rises and the cut-in speed is increased when the grinding load falls. Respective cut-in speeds with which the grinding wheel has a slower cut-in speed at a larger grinding load have been set in a manner corresponding to a plurality of respective load thresholds of the grinding load, and after starting grinding at a predetermined speed, the grinding wheel is decelerated or accelerated to a corresponding cut-in speed every time the grinding load rises or falls to a predetermined load threshold.

What is claimed is: 
     
         1 . A surface grinding method for a workpiece characterized by, when surface-grinding a workpiece by a grinding wheel, monitoring a grinding load while reducing the grinding wheel in cut-in speed with a rise in the grinding load. 
     
     
         2 . A surface grinding method for a workpiece characterized by, when surface-grinding a workpiece by a grinding wheel, monitoring a grinding load while reducing the grinding wheel in cut-in speed when the grinding load rises and increasing the cut-in speed when the grinding load falls. 
     
     
         3 . The surface grinding method for a workpiece according to  claim 1 , characterized by having set respective cut-in speeds with which the grinding wheel has a slower cut-in speed at a larger grinding load, in a manner corresponding to a plurality of respective load thresholds of the grinding load, and after starting grinding at a predetermined speed, decelerating or accelerating the grinding wheel to a corresponding cut-in speed every time the grinding load rises or falls to a predetermined load threshold. 
     
     
         4 . The surface grinding method for a workpiece according to  claim 1 , characterized by having set a returning load threshold higher than a maximum load threshold at cut-in time of the grinding wheel, and returning the grinding wheel at a predetermined return speed while grinding when the grinding load exceeds the returning load threshold. 
     
     
         5 . The surface grinding method for a workpiece according to  claim 1 , characterized by repeating a cut-in and return of the grinding wheel before spark-out. 
     
     
         6 . The surface grinding method for a workpiece according to  claim 1 , characterized by, when the grinding load exceeds a load threshold for implementation of a speed limit, even if the grinding load thereafter falls to a load threshold of a predetermined cut-in speed, causing the grinding wheel to cut in at a limit cut-in speed slower than the predetermined cut-in speed, or not making the cut-in speed faster than the limit cut-in speed. 
     
     
         7 . The surface grinding method for a workpiece according to  claim 3 , characterized by having set a returning load threshold higher than a maximum load threshold at cut-in time of the grinding wheel, and returning the grinding wheel at a predetermined return speed while grinding when the grinding load exceeds the returning load threshold. 
     
     
         8 . The surface grinding method for a workpiece according to  claim 3 , characterized by repeating a cut-in and return of the grinding wheel before spark-out. 
     
     
         9 . The surface grinding method for a workpiece according to  claim 3 , characterized by, when the grinding load exceeds a load threshold for implementation of a speed limit, even if the grinding load thereafter falls to a load threshold of a predetermined cut-in speed, causing the grinding wheel to cut in at a limit cut-in speed slower than the predetermined cut-in speed, or not making the cut-in speed faster than the limit cut-in speed. 
     
     
         10 . The surface grinding method for a workpiece according to  claim 4 , characterized by, when the grinding load exceeds a load threshold for implementation of a speed limit, even if the grinding load thereafter falls to a load threshold of a predetermined cut-in speed, causing the grinding wheel to cut in at a limit cut-in speed slower than the predetermined cut-in speed, or not making the cut-in speed faster than the limit cut-in speed. 
     
     
         11 . The surface grinding method for a workpiece according to  claim 2 , characterized by having set respective cut-in speeds with which the grinding wheel has a slower cut-in speed at a larger grinding load, in a manner corresponding to a plurality of respective load thresholds of the grinding load, and after starting grinding at a predetermined speed, decelerating or accelerating the grinding wheel to a corresponding cut-in speed every time the grinding load rises or falls to a predetermined load threshold. 
     
     
         12 . The surface grinding method for a workpiece according to  claim 2 , characterized by having set a returning load threshold higher than a maximum load threshold at cut-in time of the grinding wheel, and returning the grinding wheel at a predetermined return speed while grinding when the grinding load exceeds the returning load threshold. 
     
     
         13 . The surface grinding method for a workpiece according to  claim 2 , characterized by repeating a cut-in and return of the grinding wheel before spark-out. 
     
     
         14 . The surface grinding method for a workpiece according to  claim 2 , characterized by, when the grinding load exceeds a load threshold for implementation of a speed limit, even if the grinding load thereafter falls to a load threshold of a predetermined cut-in speed, causing the grinding wheel to cut in at a limit cut-in speed slower than the predetermined cut-in speed, or not making the cut-in speed faster than the limit cut-in speed. 
     
     
         15 . The surface grinding method for a workpiece according to  claim 11 , characterized by having set a returning load threshold higher than a maximum load threshold at cut-in time of the grinding wheel, and returning the grinding wheel at a predetermined return speed while grinding when the grinding load exceeds the returning load threshold. 
     
     
         16 . The surface grinding method for a workpiece according to  claim 11 , characterized by repeating a cut-in and return of the grinding wheel before spark-out. 
     
     
         17 . The surface grinding method for a workpiece according to  claim 11 , characterized by, when the grinding load exceeds a load threshold for implementation of a speed limit, even if the grinding load thereafter falls to a load threshold of a predetermined cut-in speed, causing the grinding wheel to cut in at a limit cut-in speed slower than the predetermined cut-in speed, or not making the cut-in speed faster than the limit cut-in speed. 
     
     
         18 . The surface grinding method for a workpiece according to  claim 12 , characterized by repeating a cut-in and return of the grinding wheel before spark-out. 
     
     
         19 . The surface grinding method for a workpiece according to  claim 13 , characterized by, when the grinding load exceeds a load threshold for implementation of a speed limit, even if the grinding load thereafter falls to a load threshold of a predetermined cut-in speed, causing the grinding wheel to cut in at a limit cut-in speed slower than the predetermined cut-in speed, or not making the cut-in speed faster than the limit cut-in speed. 
     
     
         20 . A surface grinder which in-feed grinds a workpiece by a grinding wheel, characterized by comprising: a grinding load measuring means that measures a grinding load of the grinding wheel during grinding; a speed setting means in which a plurality of grinding wheel cut-in speeds are set corresponding to a plurality of load thresholds; and a speed control means that compares the grinding load during grinding with a load threshold while accelerating or decelerating the grinding wheel, on the basis of each load threshold, at a cut-in speed corresponding to each load threshold so that the grinding wheel is reduced or increased in cut-in speed with a rise or fall in the grinding load.