Control system for surface grinding of like workpiece blanks

Claim 1

In a control process for surface grinding of a plurality of substantially like workpiece blanks to a predetermined accuracy in a precision grinding machine, which has a plurality of spindles each with a workpiece receiving component and a workpiece mount on a switchable spindle head, said control process having a control apparatus comprising a measuring sensor and an electronic measuring unit, in which said measuring sensor determines an actual height value of a workpiece blank to be worked relative to a reference point of the appropriate one of said spindles and in which said actual height value is fed to said measuring unit and said measuring unit controls said surface grinding considering said actual height value, the improvement wherein said measuring unit is associated with at least one reference workpiece of a predetermined thickness being geometrically similar to said workpiece blanks to be worked which rests on individual ones of said workpiece mounts and is measured in substantially the same way on each of said workpiece mounts as said workpiece blanks, said measuring unit has a memory to which a plurality of height measurements of said reference workpiece for said individual workpiece mounts relative to said reference points are fed as setpoint values and said measuring unit compares said actual height values of said workpiece blanks on said workpiece mounts with said setpoint values fed to said memory for said individual workpiece mounts and according to the difference between said actual height values and said setpoint values controls said surface grinding of said workpiece blanks, and wherein said measuring unit additionally detects variation in length of said spindles relative to said spindle head.