| 摘要 |
PURPOSE:To obtain an exact and efficient bolt flaw inspection device by detecting a difference between the peak of an ultrasonic reflection echo and a reference value in a neck part, a screw end part and a bolt bottom face, and detecting the peak value of the echo in another part in the course of clamping a bolt. CONSTITUTION:In each position of the neck part of a bolt 2, the screw end part and the bolt bottom face, the gates G1, G2 and G3 of a range in which an ultrasonic reflection echo inputted from an ultrasonic probe 4 can be received before and after clamping the bolt are set by a gate setting/peak detecting circuit 7. Also, in other part thereof, namely, between the gates G1 and G2, and G2 and G3, gates G4, G5 are provided, respectively. A microprocessor CPU 9 stores the peak values E1 - E3 of a reflection echo from a reference bolt received by the gates G1 - G3 as a comparison reference value, compares it with peaks X1 - X3 of the reflection echo of the bolt where a clamping work is executed, obtained by an A/D converting circuit 8 and detects the flaw. Also, in the gates G4, G5, its reflected wave echo, etc., are measured, and when its peak value exceeds a prescribed value, it is decided to be the flaw. |
