| 摘要 |
<p>PROBLEM TO BE SOLVED: To correctly detect whether or not a work is by judging that the work is not when an electrostatic capacity value detected with an electrostatic capacity sensor is smaller than a prescribed threshold even though reflected light equal to reflected light from the work is detected with a light quantity detecting sensor when the light quantity detecting sensor detects that it is not on the work. SOLUTION: Plural works 60, 62 are placed away from each other on a work receiving part 61 and a crosspiece and a frog or the like 63 of the work receiving part 61 are exposed between the works. When a nozzle part 23 of a machining device comes out of the work 60, this is detected with a light quantity detecting sensor and machining is finished. The nearly same light quantity as that from the works 60, 62 is detected from the crosspiece and the frog or the like 63 with the light quantity detecting sensor. At this time, since the detected value by the electrostatic capacity sensor is detected with a value to which a value equivalent to the thickness of the works 60, 62 is added, the detected value remains as a small value, whereby the works 60, 62 are judged that they are not. When the detected value by the electrostatic capacity sensor becomes >= a prescribed threshold value, the works 60, 62 are judged that they are.</p> |
