| 摘要 |
PROBLEM TO BE SOLVED: To provide an automatic detection device of the crack of a pipe body for detecting the presence or absence of the generation of the crack of a tube, specifying a generation part, and further detecting the size of the generated crack. SOLUTION: An automatic detection device of a pipe body crack detects a crack in a pipe body using ultrasonic waves in water being filled into the pipe body and is provided with a reflection mirror 29 with first and second reflection mirror surfaces 26 and 28 that discharge ultrasonic waves toward a pipe wall while rotating around a rotary axis 30 along the longitudinal direction of the pipe body and receive ultrasonic echoes, a rotary device 32 for rotating the reflection mirror 29 around a rotary axis, a probe 34 for transmitting ultrasonic waves in parallel with the rotary axis and receiving reflected ultrasonic echoes, and a detector 12 that can advance and retreat in the pipe body. The first reflection mirror surface 26 allows ultrasonic waves to enter a pipe wall vertically and the second reflection mirror surface 28 allows ultrasonic waves to enter the pipe wall at a specific incidence angle obliquely. The first and second reflection surfaces 26 and 28 are arranged so that they occupy an area that do not exceed 1/2 of the incidence surface of ultrasonic waves from the probe 34 and they do not mutually overlap for the incidence direction of the ultrasonic waves. |
