| 摘要 |
<p>For real-time detection of breakage of the drill, a light beam (30) may pass through along a groove of bushes (23, 24), but there are the following problems: since the bushes (23, 24) are extruded through an elastomer O-ring into a drilled hole of a turret (21), so when the bushes (23, 24) are repeatedly in contact with a substrate and pressurize the same, the bushes are gradually rotated, so that the light beam (30) is blocked to perform erroneous detection. To solve the problems, according to the present invention, the light beam (30) passes through the groove of the bushes (23, 24), and further a light projector (28) and a light receiving device (29) are installed in a position which is not in contact with a bush switching device (35). Moreover, the light projector (28) is controlled to install a detection unit detecting tool breakage by processing s signal from the light receiving device (29), and stoppers (21a, 21b) are given to be attached to the bush switching device (35) for the bushes (23, 24) not to be rotated, thereby blocking the light beam (30) for erroneous detection not to occur.</p> |
