US-12627204-B2 - Laminated iron core and laminated iron core manufacturing method

US12627204B2US 12627204 B2US12627204 B2US 12627204B2US-12627204-B2

Abstract

A laminated iron core includes a laminated body including a plurality of laminated metal sheets. The laminated body includes a welded portion where an endmost metal sheet located at an endmost position in a lamination direction and the metal sheet in contact with the endmost metal sheet are welded. A welding end of the welded portion is in contact with at least one endmost metal sheet.

Inventors

Go Kato
Yasutaka Ohba
Yuki Tokimoto
Tetsuya Hirakawa

Assignees

MITSUI HIGH-TEC, INC.

Dates

Publication Date: 20260512
Application Date: 20240312
Priority Date: 20230315

Claims (10)

1 . A laminated iron core comprising: a laminated body including a plurality of laminated metal sheets, wherein the laminated body includes: a first welded portion where a first endmost metal sheet located at a first endmost position in a lamination direction and the metal sheet in contact with the first endmost metal sheet are welded, and a second welded portion where a second endmost metal sheet located at a second endmost position in the lamination direction opposite the first endmost position and the metal sheet in contact with the second endmost metal sheet are welded, and wherein a first welding end of the first welded portion is in contact with the first endmost metal sheet, and a second welding end of the second welded portion is in contact with the second endmost metal sheet.
2 . The laminated iron core according to claim 1 , wherein the first welded portion has a plurality of crescent-shaped welding marks, and wherein the plurality of welding marks protrude in a direction away from the first endmost metal sheet.
3 . The laminated iron core according to claim 2 , wherein the plurality of welding marks are arranged in a row.
4 . The laminated iron core according to claim 2 , wherein the plurality of welding marks are arranged in a plurality of rows.
5 . The laminated iron core according to claim 1 , wherein the laminated body has a through hole penetrating along the lamination direction, and wherein a magnet extending along the lamination direction is sealed with a resin inside the through hole.
6 . A laminated iron core manufacturing method comprising: a laminated body forming process of forming a laminated body by laminating a plurality of metal sheets; and a welding process of welding a first endmost metal sheet located at a first endmost position in a lamination direction of the laminated body and the metal sheet in contact with the first endmost metal sheet and welding a second endmost metal sheet located at a second endmost position in the lamination direction opposite the first endmost position and the metal sheet in contact with the second endmost metal sheet, wherein in the welding process, a position in contact with each of the first and the second endmost metal sheets is welded last.
7 . The laminated iron core manufacturing method according to claim 6 , wherein in the welding process, welding is first performed at a position away from the first endmost metal sheet, and welding is performed a plurality of times at positions gradually approaching a position in contact with the first endmost metal sheet.
8 . The laminated iron core manufacturing method according to claim 7 , wherein in the welding process, welding is performed a plurality of times such that welding marks are arranged in a row.
9 . The laminated iron core manufacturing method according to claim 7 , wherein in the welding process, welding is performed a plurality of times such that welding marks are arranged in a plurality of rows.
10 . The laminated iron core manufacturing method according to claim 6 , further comprising: a process of inserting a magnet into a through hole penetrating the laminated body along the lamination direction; and a process of sealing the magnet with a resin.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2023-040206 filed on Mar. 15, 2023, the contents of which are incorporated herein by reference. TECHNICAL FIELD An embodiment disclosed herein relates to a laminated iron core and a laminated iron core manufacturing method. BACKGROUND ART A laminated iron core constituting a stator or a rotor of a motor is manufactured by, for example, feeding a strip-shaped metal sheet to a die device sequentially, performing punching sequentially at processing stations located side by side along a feeding direction of the metal sheet to form iron core pieces of a desired shape, and laminating the obtained iron core pieces. In the laminated iron core, in order to prevent separation of an iron core piece located at an endmost position in a lamination direction (hereinafter also referred to as an endmost iron core piece), a technique of welding the endmost iron core piece and an iron core piece adjacent to the endmost iron core piece is used. CITATION LIST Patent Literature Patent Literature 1: JP5278551B On the other hand, in a welding process, cracks may occur in a welded portion due to residual stress in a tensile direction generated when the welded portion contracts during cooling. As a result, welding quality of the laminated iron core may deteriorate. SUMMARY An aspect of the embodiment has been made in view of the above, and an object thereof is to provide a laminated iron core and a laminated iron core manufacturing method that can improve the welding quality. A laminated iron core according to an aspect of an embodiment includes a laminated body including a plurality of laminated metal sheets. The laminated body includes a welded portion where an endmost metal sheet located at an endmost position in a lamination direction and the metal sheet in contact with the endmost metal sheet are welded. A welding end of the welded portion is in contact with at least one endmost metal sheet. A laminated iron core manufacturing method according to an aspect of the embodiment includes a laminated body forming process and a welding process. In the laminated body forming process, a plurality of metal sheets are laminated to form a laminated body. In the welding process, an endmost metal sheet located at an endmost position in a lamination direction of the laminated body and the metal sheet in contact with the endmost metal sheet are welded. In the welding process, a position in contact with at least one endmost metal sheet is welded last. According to an aspect of the embodiment, the welding quality of the laminated iron core can be improved. The effects described herein are not necessarily limited, and may be any of the effects described in the present disclosure. BRIEF DESCRIPTION OF DRAWINGS FIG. 1A is a schematic diagram showing an example of a laminated iron core according to an embodiment. FIG. 1B is a cross-sectional view taken along line X-X shown in FIG. 1A. FIG. 2 is a schematic view showing an example of a manufacturing device for a laminated iron core according to the embodiment. FIG. 3 is a flowchart showing an example of a procedure of each manufacturing process performed by the manufacturing device for a laminated iron core according to the embodiment. FIGS. 4A to 4C are diagrams illustrating an example of a welding process according to a reference example. FIGS. 5A to 5C are diagrams illustrating an example of a welding process according to the embodiment. FIGS. 6A to 6C are diagrams illustrating an example of a welding process according to a first modification of the embodiment. FIGS. 7A to 7C are diagrams illustrating an example of a welding process according to a second modification of the embodiment. DESCRIPTION OF EMBODIMENTS Hereinafter, a laminated iron core and a laminated iron core manufacturing method disclosed in the present application will be described with reference to the accompanying drawings. It should be noted that the present disclosure is not limited by the embodiments shown below. It should be noted that the drawings are schematic, and a dimensional relationship of elements, ratios of the elements, and the like may differ from reality. Further, even between the drawings, there are cases where portions having different dimensional relationships and ratios are included. Laminated Iron Core First, a configuration of a laminated iron core 1 according to an embodiment will be described with reference to FIG. 1A and FIG. 1B. FIG. 1A is a schematic diagram showing an example of the laminated iron core 1 according to the embodiment, and FIG. 1B is a cross-sectional view taken along line X-X shown in FIG. 1A. The laminated iron core 1 is, for example, a rotor laminated iron core, and is a part of a rotor. A motor is formed by combining the rotor with a stator. The laminated iron core 1 according to the embodiment is used in, for example, an interior permanent magn