CN-122003600-A - Defect detection device and method for manufacturing defect detection device

CN122003600ACN 122003600 ACN122003600 ACN 122003600ACN-122003600-A

Abstract

The defect detection device is a defect detection device for detecting a defect of a rotor core, which is cylindrical with an axis as a center, and has a plurality of slots recessed from an outer peripheral surface toward a radial inner side and arranged at intervals in a circumferential direction, the slots having a head portion formed by a pair of first surfaces that open toward the outer peripheral side and extend in the radial direction when viewed in the axial direction, a dovetail portion formed by a pair of inclined surfaces that communicate with the head portion and that gradually expand in the circumferential interval toward the inner peripheral side, and a trunk portion formed by a pair of second surfaces that communicate with the dovetail portion and extend in the radial direction, and the defect detection device has a device body having a first inspection surface that abuts against the first surfaces, an inclined inspection surface that abuts against the inclined surfaces, and a second inspection surface that abuts against the second surfaces, a plurality of array coils that are buried inside the first inspection surface, the inclined inspection surface, and the second inspection surface, respectively, and a plurality of permanent magnets that are arranged in parallel to the array coils.

Inventors

URATA MIKIYASU
KATO TAKASHI
YAMAGUCHI TAKEHIKO
Hisashi Yoshiharu
Kana Kentaro
Zhong Yongtai Announcement
OHTOMO ATSUSHI
Erlang Murakami

Assignees

三菱发电机株式会社

Dates

Publication Date: 20260508
Application Date: 20231012

Claims (7)

1. A defect detecting device for detecting a defect of a rotor core having a columnar shape centered on an axis and having a plurality of slits recessed from an outer peripheral surface toward a radial inner side and arranged at intervals in a circumferential direction, The slot has a head portion formed by a pair of first faces that open toward an outer peripheral side and extend in a radial direction when viewed in the axial direction, a dovetail portion formed by a pair of inclined faces that communicate with the head portion and whose circumferential intervals gradually expand toward an inner peripheral side, and a trunk portion formed by a pair of second faces that communicate with the dovetail portion and extend in the radial direction, The defect detection device comprises: a device body having a first inspection surface in contact with the first surface, an inclined inspection surface in contact with the inclined surface, and a second inspection surface in contact with the second surface; A plurality of array coils embedded in the first inspection surface, the inclined inspection surface and the second inspection surface, respectively, and And a plurality of permanent magnets arranged in parallel with the array coil.
2. The defect detecting apparatus of claim 1, wherein, The plurality of array coils are different from each other in radial positions when viewed from the axis direction, and a part of each of the array coils overlaps with each other in the radial direction.
3. The defect detecting apparatus according to claim 1 or 2, wherein, And a plurality of array coils, a part of which is arranged at a corner between the first inspection surface and the inclined inspection surface and a corner between the inclined inspection surface and the second inspection surface.
4. The defect detecting apparatus according to claim 1 or 2, wherein, The permanent magnets are each provided with a pair so as to sandwich the array coil from both sides in the axial direction.
5. The defect detecting apparatus according to claim 1 or 2, wherein, The device further includes holding portions provided at end portions of the device body on both sides in the axial direction, respectively.
6. The defect detecting apparatus according to claim 1 or 2, wherein, And a film-shaped abrasion-resistant member covering the first inspection surface, the inclined inspection surface, and the second inspection surface.
7. A method for manufacturing a defect detecting device, the defect detection apparatus is the method for manufacturing a defect detection apparatus according to claim 1 or 2, comprising: a step of acquiring the size of each portion related to the shape of the slit; a step of forming the device body by three-dimensional lamination molding based on the dimensions, and And a step of installing the array coil and the permanent magnet.

Description

Defect detection device and method for manufacturing defect detection device Technical Field The present disclosure relates to a defect detection apparatus and a method of manufacturing the defect detection apparatus. Background In order to realize stable operation of a large-sized generator (motor) used in a power plant or the like, it is necessary to detect defects in each part due to aged operation with high accuracy. In particular, a load due to centrifugal force acts on the rotor core as a rotating body. Therefore, defects such as cracks due to stress concentration are likely to occur in each portion of the rotor core. Here, a member called a wedge for preventing the coils from flying out is inserted into a slot formed in the outer peripheral surface of the rotor core for accommodating the coils. The wedge is fitted from the inner peripheral side to a dovetail portion formed on the inner surface of the slot. Since centrifugal force is applied to the wedge, a load is particularly easily applied to the dovetail portion. As a technique for detecting a defect of a tongue portion, a technique described in patent document 1 below is known. The device of patent document 1 described below mainly includes a jig that can be abutted against the inner surface of a notch including a tenon portion, and a pressing mechanism for pressing the jig to the notch. Prior art literature Patent literature Patent document 1 Japanese patent No. 6121711 Disclosure of Invention Technical problem to be solved by the invention However, in the case where the jig is pressed against the inner surface of the notch by the pressing mechanism alone as described above, the jig may float up (float up) and affect the detection accuracy of the defect when the jig is moved along the notch. Further, since the rotor core of the motor is generally a magnetic body, there is a disadvantage in that the detection accuracy is lowered due to magnetic noise. The present disclosure has been made to solve the above-described problems, and an object thereof is to provide a defect detection device capable of stably performing defect detection with high accuracy, and a method for manufacturing the defect detection device. Technical proposal adopted for solving the technical problems In order to solve the above-described problems, a defect detection device according to the present disclosure is a defect detection device for detecting a defect of a rotor core having a cylindrical shape centered on an axis and having a plurality of slots recessed from an outer peripheral surface toward a radially inner side and arranged at intervals in a circumferential direction, the slots having a head portion formed of a pair of first surfaces that open toward the outer peripheral side and extend in the radial direction when viewed in the axis direction, a dovetail portion formed of a pair of inclined surfaces that communicate with the head portion and that gradually expand at intervals in the circumferential direction toward an inner peripheral side, and a trunk portion formed of a pair of second surfaces that communicate with the dovetail portion and extend in the radial direction, the defect detection device having a device body having a first inspection surface that abuts against the first surfaces, an inclined inspection surface that abuts against the inclined surfaces, and a second inspection surface that abuts against the second surfaces, a plurality of array coils that are buried in the first inspection surface, the inclined inspection surface, the second inspection surface, and the array coils that are juxtaposed with the plurality of permanent magnets. The manufacturing method of the defect detecting device of the present disclosure is a manufacturing method of the defect detecting device described above, and includes a step of obtaining a size of each portion related to a shape of the slit, a step of forming the device body by three-dimensional lamination molding based on the size, and a step of mounting the array coil and the permanent magnet. Effects of the invention According to the present disclosure, a defect detection device capable of stably performing defect detection with high accuracy and a method for manufacturing the defect detection device can be provided. Drawings Fig. 1 is a sectional view showing a structure of a rotor core of an electric motor. Fig. 2 is an enlarged view of a main portion of a rotor core, and is a sectional view showing a structure of a defect detecting device of an embodiment of the present disclosure. Fig. 3 is a front view showing the structure of a defect detection apparatus of an embodiment of the present disclosure. Fig. 4 is an explanatory diagram showing the arrangement of the array coil of the embodiment of the present disclosure, and is an expanded view of each face of the device main body. Fig. 5 is a flowchart showing steps of a method of manufacturing a defect detection device according to an embodiment of the present