JP-7854875-B2 - Leakage flux detection probe

Inventors

• 小畠 卓也
• 古田 久人
• 原田 浩幸
• 後藤 壮善
• 村松 潤
• 小原 史郎

Assignees

• 株式会社カナデビアエンジニアリング
• 株式会社ネクスコ・エンジニアリング北海道
• ＡＣＴＵＮＩ株式会社

Dates

Publication Date

20260507

Application Date

20220630

Claims (3)

1. A magnetic sensor is provided in the center of the U-shaped magnetization core, A rectangular parallelepiped sensor case housing the aforementioned U-shaped magnetization core, A leakage flux inspection probe comprising the U-shaped magnetization core positioned diagonally within the sensor case so that the magnetic sensor is located near the end of the sensor case.
2. The leakage flux inspection probe according to claim 1, wherein the number of turns of the magnetization coil is 300 or more.
3. The leakage flux inspection probe according to claim 1, wherein the end of the sensor case on the side where the magnetic sensor is located is chamfered.

Description

This invention relates to a leakage flux inspection probe and a crack evaluation system, and more particularly to a leakage flux inspection probe and a crack evaluation system capable of detecting cracks at an early stage. Traditionally, inspections of areas of metal columns where cracks or other damage are expected have primarily relied on visual inspection. If a crack is suspected during the visual inspection, penetrant testing or magnetic particle testing is performed on the area to confirm its presence. Both non-destructive testing methods require the removal of any coatings or plating beforehand. Furthermore, visual inspections can be influenced by the inspector's experience and skill, and it can be difficult to detect cracks through coatings. Figures 10(A) to 10(D) show areas in the metal column where crack formation is suspected and their specific locations. Figure 10(A) shows a crack 27 in the axial direction of the weld, Figure 10(B) shows a crack 28 in the circumferential direction of the weld, Figure 10(C) is a cross-sectional view showing the axial cross-section of the weld shown in Figures 10(A) and 10(B), and Figure 10(D) is a cross-sectional view showing the circumferential cross-section. Referring to Figures 10(A) to 10(D), cracks 27 and 28 occur near the weld 30 between the metal column 125 and the rib 29. Cracks 27 and 28 include cracks that occur along the weld toe (cracks that do not propagate into the column base material) and cracks that occur in the column plate thickness direction (cracks that propagate into the column base material). The figures also show the direction of crack formation at the areas where crack formation is expected. Among these, the leakage flux inspection probe targets the initial stage of cracks that have propagated from the weld toe to the column base material. Furthermore, a conventional apparatus for inspecting cracks in welded joints is disclosed, for example, in Japanese Patent Publication No. 2019-20273 (Patent Document 1). Japanese Patent Publication No. 2019-20273 (Abstract, etc.) This is a perspective view showing an improved leakage flux inspection probe according to one embodiment of the present invention.This figure shows an image of crack detection using an improved magnetic flux leakage detection probe.This is a diagram showing a leakage flux inspection probe.This is a diagram showing the main body of the device.This is a block diagram showing the configuration of a crack evaluation system.This is a flowchart showing the operation of the crack evaluation system.This diagram shows a method for evaluating crack depth.This diagram shows the X-axis origin correction function.This figure shows an example of a display screen for measurement results.This figure shows examples of crack formation in metal pillars.This is a diagram showing a typical leakage flux detection probe.This figure shows an image of crack detection using a typical magnetic flux leakage detection probe.This figure shows an image of a crack inspection system using a magnetic flux leakage detection probe. Hereinafter, an embodiment of this invention will be described with reference to the drawings. First, in this embodiment, a leakage flux inspection probe having a diagonally positioned magnetization core (hereinafter referred to as a "diagonal magnetization core") is used. Therefore, this leakage flux inspection probe having a diagonal magnetization core will be described. Figure 1(A) is a perspective view showing a leakage flux inspection probe (inclined probe) 10, which is an inspection probe according to one embodiment of this invention. Figure 1(B) shows the state in which a crack 121 originating from the weld toe 122 of a fillet weld 120 is detected using the leakage flux inspection probe 10. First, referring to Figure 1(A), the leakage flux inspection probe 10 is designed so that the magnetic sensor 15 is positioned closer to the edge of the sensor case 13 than in the conventional inspection probe 110, by tilting the magnetization core 11 located inside the leakage flux inspection probe 10. Specifically, the leakage flux inspection probe 10 includes an angled magnetization core 11 housed in a cubic sensor case 13. The U-shaped magnetization core 11 includes a magnetization coil 12 wound around its center, and a rectangular magnetic sensor 15 formed in the center of the U-shaped magnetization core 11 detects cracks. The leakage flux inspection probe 10, which has an angled magnetization core 11, has a U-shaped magnetization core positioned at an angle such that the detection part of the magnetic sensor 15 is located in the center near one side of the bottom of the sensor case 13. Furthermore, as shown in Figure 1(B), the sensor case 13 of the leakage flux inspection probe 10 has a predetermined thickness at the end where the magnetic sensor 15 is located. To bring the magnetic sensor 15 as close as possible to the weld toe 122 (the measurement area) during measurement, the end of