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Eddy current flaw detection device and eddy current flaw detection method

An eddy current flaw detection and eddy current technology, used in measuring devices, instruments, scientific instruments, etc., can solve the problems of reduced sensitivity, low conductivity of composite materials, and reduced eddy current density, and achieve a simple and low-cost device structure, high-sensitivity defect detection. Effect

Pending Publication Date: 2021-03-16
TOSHIBA FUEL CELL POWER SYST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] On the other hand, composite materials composed of two or more different materials may have a lower electrical conductivity than metal materials due to the use of laminated structures or the use of fibers, etc.
If such a composite material is used as the inspection object of eddy current flaw detection, the electrical conductivity of the composite material is low, so the eddy current density induced by the composite material is reduced.
Therefore, the magnetic flux density of the reaction magnetic field generated by the eddy current is also reduced, and the sensitivity of defect detection is reduced

Method used

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  • Eddy current flaw detection device and eddy current flaw detection method
  • Eddy current flaw detection device and eddy current flaw detection method
  • Eddy current flaw detection device and eddy current flaw detection method

Examples

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no. 1 approach

[0028] figure 1 It is a schematic cross-sectional view showing the state during flaw detection of the eddy current flaw detector according to the first embodiment of the present invention.

[0029] In this first embodiment, the object 11 to be inspected is made of a composite material having a lower electrical conductivity than a normal metal material. The composite material can be, for example, a composite material using silicon carbide fibers, carbon fiber reinforced plastic (CFRP), glass fiber reinforced plastic (GFRP), and the like. The test object 11 is, for example, flat and has a first plane 12 and a second plane 13 parallel to the first plane 12 on its back side. It is assumed that a defect portion (thin portion) 14 exists on the first plane 12 .

[0030] The eddy current testing apparatus of the first embodiment has an exciter 20 as a first excitation detector and a detector 21 as a second excitation detector. The exciter 20 and the detector 21 are, for example, he...

no. 2 approach

[0040] figure 2 It is a schematic cross-sectional view showing the state during flaw detection of the eddy current flaw detector according to the second embodiment of the present invention.

[0041] The eddy current testing apparatus of this second embodiment has a first excitation detector 25 and a second excitation detector 26 .

[0042]The first excitation detector 25 and the second excitation detector 26 are, for example, helical coils. The first excitation detector 25 is arranged in contact with the first flat surface 12 of the object 11 to be inspected, and the second excitation detector 26 is arranged in contact with the second flat surface 13 of the object to be inspected 11 . The first excitation detector 25 and the second excitation detector 26 are arranged such that the axes A of their coils face the first plane 12 and the second plane 13 vertically. The first excitation detector 25 is connected to the AC power supply 22, and the second excitation detector 26 is ...

no. 3 approach

[0049] image 3 It is a schematic cross-sectional view showing the state during flaw detection of the eddy current flaw detector according to the third embodiment of the present invention.

[0050] The third embodiment is a modification of the second embodiment, and the outer portions of the first excitation detector 25 and the second excitation detector 26 that do not face the object 11 are covered with a ferromagnetic cover 30 . Other structures are the same as those of the second embodiment.

[0051] According to this third embodiment, the action / effect of the second embodiment can be obtained, and the magnetic field generated by supplying an alternating current to the first excitation detector 25 and the second excitation detector 26 forms a The distribution of the resulting magnetic circuit increases the magnetic flux density. Thereby, the magnetic flux density which passes through the defect part 14 and interlinks with the 1st excitation detector 25 or the 2nd excitati...

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Abstract

This eddy current flaw detection device according to one embodiment includes: a first exciter / detector 20 that can induce an eddy current at an examination body 11 by imparting a magnetic-field changein the examination body 11 by the supply of an alternating current; and a second exciter / detector 21 that is disposed on the opposite side as the first exciter / detector 20 with the examination body 11 therebetween, and that can detect a change in a reaction magnetic field generated by the eddy current induced at the examination body 11.

Description

technical field [0001] Embodiments of the present invention relate to an eddy current flaw detection device and an eddy current flaw detection method. Background technique [0002] In general, eddy current flaw detection uses metallic materials as the inspection object, supplies an AC current from an AC power source to an excitation coil, induces an eddy current near the surface of the inspection object, and detects the reaction magnetic field generated by the eddy current with a detection coil. If there is a defect near the surface of the object to be inspected, the flow of the eddy current changes due to the defect, and the strength and distribution of the reaction magnetic field generated by the eddy current also change, so the presence or absence of the defect can be detected. [0003] On the other hand, a composite material composed of two or more different materials may have a lower electrical conductivity than a metal material due to its laminated structure or use of ...

Claims

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Application Information

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IPC IPC(8): G01N27/9093
CPCG01N27/90G01N27/904
Inventor 小林德康千星淳秋元惠鹈饲胜
Owner TOSHIBA FUEL CELL POWER SYST