PURPOSE: To obtain an eddy current flaw detector having high performance, by placing 4 moving pieces energized to the outside by a spring, on a fixed shaft whose section is square, and providing a pair of detecting coils whose section is fan-shaped.
CONSTITUTION: 4 moving pieces 416 are placed to a fixed shaft 420 whose section is a square, both its ends are inserted into guide cylinders 430, 431, and they are energized in the outside direction by V type plate springs 426, 427. In the center of the moving piece 416, detecting coils 411, 412 are wound round a magnetic core 413 whose section is fan-shaped, it is sealed by a copper plate 414, and is connected to a flaw detector by a lead wire 415. According to such a constitution, each detecting coil closely contacts with a pipe to be detected, by a spring action, and as for an eddy current working on the pipe to be detected, the eddy current is generated within a short range as shown by a part Z' in the figure. Therefore, influence of a factor except a defect is reduced, and the defect can be detected with high performance.
KAMIMURA TAKEO
ARAKI YASUO
MISASA MASAHIRO
MARUTA ATSUSHI
SEIRYO ENG
| JP55132665B |