To provide a machine tool accurately detecting a vibration of a rotary table, which occurs when the rotary table causes a rotational imbalance, without the need of adding a vibration sensor for detecting the vibration of the rotary table.
When causing the rotational imbalance, the rotary table 30 vibrates according to its rotational speed and the amount of imbalance. This vibration appears as a vibration in position droop in the X-axis direction via a ball screw 16. A centrifugal force of the rotary table 30 and an amplitude thereof at vibration time are correlated with each other, and the centrifugal force and the position droop in the X-axis direction are correlated with each other as well. As the amplitude and the position droop are correlated with each other, in other words, a main controller 110 monitors the variation in the position droop in the X-axis direction to detect the vibration of the rotary table 30.
YAMAMOTO TORU
SUZUKI YASUHIKO
OKADA SATOSHI
KURATA MASAHIRO
| JP2002149241A | 2002-05-24 |
Makoto Onda