Rotary eddy current testing probe device
View Patent ↗A rotary eddy current flaw detection probe device has a plurality of Θ-shaped eddy current flaw detection probes attached in a rotating disc for detecting flaws in all directions regardless of the flaw direction. Four Θ-shaped eddy current testing probes P 11 to P 22 are arranged around the rotation center Ds 1 of a rotating disc 111 and are embedded in the disc 111 . The coil planes of detector coils Ds 11 to Ds 22 of the testing probes P 11 to P 22 are parallel with each other, and are perpendicular to the rotation plane of the rotating disc 111 . The coil planes of the detector coils incline at an angle θ relative to a line Y passing through the centers Ps 11 and Ps 12 of the probes P 11 and P 12 . The detector coils Dc 11 and Dc 12 are cumulatively connected to each other and the detector coils Dc 21 and Dc 22 are differentially connected to each other.
1. A rotary eddy current testing probe device for detecting flaws on an object being inspected, comprising:
a rotating disc ( 111 ); and
four eddy current testing probes (P 11 , P 21 , P 12 , P 22 ) attached at approximately equal intervals in a circumferential direction around a rotation center (Ds 1 ) of the rotating disc ( 111 ), wherein
the four eddy current testing probes (P 11 , P 21 , P 12 , P 22 ) are composed of two sets of the eddy current testing probes, each one set including two eddy current testing probes located on opposite sides with respect to a rotation center (Ds 1 ), and each of the four eddy current testing probes has a circular exciting coils (Ec 11 , Ec 21 , Ec 12 , Ec 22 ) for exciting a current in the object being inspected, and a rectangular detector coils (Dc 11 , Dc 21 , Dc 12 , Dc 22 ) disposed on an inside of the exciting coil for detecting the current exited in the object being inspected;
coil planes of the exciting coils (Ec 11 , Ec 21 , Ec 12 , Ec 22 ) are parallel with a rotation plane of the rotating disc;
coil planes of the detector coils (Dc 11 , Dc 21 , Dc 12 , Dc 22 ) are perpendicular to the rotation plane of the rotating disc;
the coil planes of the four detector coils (Dc 11 , Dc 21 , Dc 12 , Dc 22 ) are parallel with each other, and incline at a predetermined angle (θ) relative to a line (Y 1 ) passing through the respective centers of two eddy current testing probes of one set of the two-set eddy current testing probes; and
the two detector coils (Dc 11 , Dc 12 ) of the one set of eddy current testing probes are cumulatively connected to each other, and the two detector coils (Dc 21 , Dc 22 ) of the other set of eddy current testing probes are differentially connected to each other.
2. The rotary eddy current testing probe device according to claim 1 , wherein the predetermined angle (θ) is 15 to 60 degrees.
3. The rotary eddy current testing probe device according to claim 1 , wherein a ratio (W1:W2) of a distance (W 1 ) from a center (Ps 11 , Ps 12 ) of respective eddy current testing probes of one set to a rotation center (Ds 1 ) of the rotating disc to a distance (W 2 ) from a center (Ps 21 , Ps 22 ) of respective eddy current testing probes of the other set to the rotation center (Ds 1 ) of the rotating disc is 1:1 to 1:3.
4. The rotary eddy current testing probe device according to claim 3 , wherein in the case where an inspection surface of the object being inspected has a curvature, the ratio (W1:W 2 ) is 1:1.75.
5. The rotary eddy current testing probe device according to claim 1 , wherein the predetermined angle (θ) is 45 degrees.