JPS58223743A - Orthogonal probe coil - Google Patents

Abstract

PURPOSE:To detect a defect and its direction simultaneously, by arranging an interelectrode energizing coil and a coil perpendicular to the axis connecting both ends of the former coil between electrodes. CONSTITUTION:The energizing coil 2 wound around an interelectrode core 1 is connected to an AC or pulse power source 3 to form the interelectrode energizing coil. A core 4 for detection is provided in the middle of the interelectrode core 1 and the detection coil 5 is wound at right angles to the line connecting both electrodes of the interelectrode core 1 and connected to a detector 6. When current is generated at the AC or pulse power source 3, a line of magnetic force passes between both electrodes of the interelectrode core 1, but the detection coil 5 is at right angles, no indication is generated at a detector 6.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a probe coil for eddy current flaw detection, and particularly to an orthogonal probe coil suitable for detecting the direction of a detected defect.

Conventional probe coils for eddy current flaw detection have an excitation coil and a detection coil coaxially wound around a cylindrical core, so they have the disadvantage that they do not have a function to detect the direction of a linear defect.

An object of the present invention is to provide an orthogonal globe coil that can detect defects and detect the direction of the detected defects in eddy current flaw detection of surface linear defects using a globe coil.

We focused on the fact that when the excitation coil has a pole-to-pole shape, the current value induced in the detection coil differs depending on the direction of the line connecting the two poles and the angle at which the linear defect intersects.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an overall front view and a plan view of the orthogonal probe coil, and a state in which the orthogonal probe coil is brought into contact with a specimen to be tested for flaw detection. The excitation coil 2 wound around the pole-to-pole type core 1 is connected to an alternating current or pulse power source 3 to form a pole-to-pole type excitation coil. The detection core 4 is installed and fixed in the middle of the pole-to-pole type core 1, and a detection coil 5 is wound perpendicularly to a line connecting the two poles of the pole-to-pole type core 10, and connected to a detector 6. . In FIG. 1, when a current is generated in the alternating current or pulse power source 3, magnetic lines of force pass between the two poles of the interpolar core 10, but since the detection coils 5 are perpendicular to each other, no indication is generated on the detector 6.

FIG. 2 shows a top view when the orthogonal probe coil is arranged so that the direction of both poles and the direction of the defect 8 match.
As above, no indication appears on the detector.

FIG. 3 shows a top view when the orthogonal globe coil is arranged so that the direction of both poles and the defect 8 intersect at 45 degrees.

In this case, the lines of magnetic force flowing between the two poles are perpendicular to the detection coil, so no indication is generated on the detector 6, but an eddy current 9. and 10
Due to the defect 8, this eddy current 9. lO flows obliquely to the axis of the detection coil 5. Detection coil 5
The eddy current 9.10 flowing obliquely to the axis generates an induced voltage in the detection coil 5 and gives an indication to the detector 6.

According to this embodiment, there is an effect that the directionality of the detected defect can be detected.

According to the present invention, there is an effect that the directionality of defects detected in probe-type eddy current flaw detection of the surface layer of a metal material can be detected.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the direct-fired probe coil, Figure 2 is a top view of the direct-fired probe coil arranged so that the direction of both poles matches the direction of the defect, and Figure 3 is a 45° intersection. A top view is shown when the device is arranged as shown in FIG.

Claims (1)

[Claims] 1. An orthogonal globe type coil characterized in that a pole-to-pole type excitation coil and a coil orthogonal to an axis connecting both ends of the pole-to-pole type excitation coil are installed between the poles.