| 摘要 |
PROBLEM TO BE SOLVED: To accurately judge the exchange timing of a roller bit by monitoring the wear condition of the roller bit even if a worker does not enter a chamber. SOLUTION: A roller bit 121 is mounted to a slide take-in hole 122 of a cutter head 12 of a shield advancing machine 10, and a sensing probe 21 is mounted close to the blade tip of the outer periphery of the roller bit 121. When the sensing coil of each sensing probe 21 is excited by an excitation voltage E from a frequency oscillation part 251 of an eddy current flaw-detection control device 25, an eddy current is generated at the roller bit 12 by its alternate magnetic field and an induction electromotive force being outputted by the self induction of the sensing coil changes according to the level of the wear and damage of the roller bit 121, thus detecting the wear and damage of the roller bit 121 by receiving the output signal V using the eddy current flaw- detection control device 25 and a personal computer 26. |
