Apparatus for detecting and indicating the balance of a rotary body in a machine tool

An apparatus for detecting and indicating the balance of a rotating body in a machine tool, comprising:

• origin-point detecting means for detecting an origin-point on the rotating body;
• vibration detecting means for detecting vibration caused by an unbalanced condition of the rotating body;
• arithmetic means for computing, from the detected vibration, off-center deviation data of the rotating body at each of a plurality of index positions on the rotating body which are angularly spaced from the origin-point as a reference,
• the arithmetic means comprising means for computing as many deviation data as are able to be processed in one revolution of the rotating body from the origin-point and storing them in memory means connected to the arithmetic means, dividing the total number of the deviation data by the number of the index positions, totaling the magnitudes of the deviation data for the index positions, and dividing the total of said deviation magnitudes at said index positions by the number of deviation data for the index positions, thereby computing a primary average deviation data and storing said primary average deviation data in the memory means,
• the arithmetic means comprising means for totaling the primary average deviation data for the index positions in a predetermined number of revolutions of the rotating body, dividing the total deviation amount of the primary deviation data by the number of revolutions, and computing a secondary average deviation data for the index positions, thereby selecting a maximum deviation data and an index position where the maximum deviation is produced by comparing the secondary average deviation data for the index positions;
• unbalanced position indicating means for indicating the index position where the maximum deviation is produced;
• and
• display means for displaying a value corresponding to the maximum deviation.