Inspection method and inspection device for membrane electrode assembly

Patent metadata

Field	Value
Publication number	US-11781998-B2
Application number	US-202217670910-A
Country	US
Kind code	B2
Filing date	Feb 14, 2022
Priority date	Mar 15, 2021
Publication date	Oct 10, 2023
Grant date	Oct 10, 2023

Abstract

An inspection method of a membrane electrode assembly includes a first process of acquiring an X-ray transmission image of the membrane electrode assembly, a second process of identifying a luminance-reduced region having a luminance lower than a luminance of a surrounding region in the X-ray transmission image acquired in the first process, a third process of correcting the luminance of the luminance-reduced region identified in the second process, in accordance with a planar size of the luminance-reduced region, based on a correlation between a planar size of a foreign matter in the membrane electrode assembly and change in luminance due to diffraction of X-rays, and a fourth process of finding a thickness of the foreign matter in the membrane electrode assembly based on the luminance corrected in the third process.

First claim

What is claimed is:

1. An inspection method of a membrane electrode assembly, the inspection method comprising:
a first process of acquiring an X-ray transmission image of the membrane electrode assembly;
a second process of identifying a luminance-reduced region having a luminance lower than a luminance of a surrounding region in the X-ray transmission image acquired in the first process;
a third process of correcting the luminance of the luminance-reduced region identified in the second process, in accordance with a planar size of the luminance-reduced region, based on a correlation between a planar size of a foreign matter in the membrane electrode assembly and change in luminance due to diffraction of X-rays; and
a fourth process of finding a thickness of the foreign matter in the membrane electrode assembly based on the luminance corrected in the third process.

2. The inspection method according to claim 1 , further comprising a fifth process of finding a three-dimensional size of the foreign matter, based on the thickness found in the fourth process and the planar size of the luminance-reduced region.

3. The inspection method according to claim 2 , further comprising a sixth process of performing quality determination processing for determining whether the membrane electrode assembly is defective or non-defective, by comparing the three-dimensional size of the foreign matter found in the fifth process with a defect determination threshold value set in advance.

4. An inspection device of a membrane electrode assembly, the inspection device comprising:
an acquisition unit configured to acquire an X-ray transmission image of the membrane electrode assembly; and
a processing unit configured to
identify a luminance-reduced region having a luminance lower than a luminance of a surrounding region in the X-ray transmission image,
correct the luminance of the luminance-reduced region in accordance with a planar size of the luminance-reduced region, based on a correlation between a planar size of a foreign matter in the membrane electrode assembly and change in luminance due to diffraction of X-rays, and
find a thickness of the foreign matter in the membrane electrode assembly based on the corrected luminance.

5. The inspection device according to claim 4 , wherein the processing unit is configured to find a three-dimensional size of the foreign matter, based on the thickness found by the processing unit and the planar size of the luminance-reduced region.

6. The inspection device according to claim 5 , wherein the processing unit is configured to perform quality determination processing for determining whether the membrane electrode assembly is defective or non-defective, by comparing the three-dimensional size of the foreign matter with a defect determination threshold value set in advance.

Assignees

• Toyota Motor Co Ltd
• Hitachi High Tech Science Corp

Inventors

• Takeshita Shinya
• Takahara Toshiyuki

Classifications

• G01N23/18 Primary

  Investigating the presence of flaws defects or foreign matter · CPC title

• G01B15/025 Primary

  by measuring absorption · CPC title

• G01N23/04

  and forming images of the material · CPC title

• G01N23/083 Primary

  the radiation being X-rays · CPC title

• G01N2223/04

  and measuring absorption · CPC title