# US 11,121,610 B2 · Method of manufacturing laminated core

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- Number: US 11,121,610 B2
- Document ID: US11121610B2
- Status: Granted
- Kind: B2
- Application number: 16/158,633
- Filed: 2018-10-12
- Published: 2019-04-18
- Granted: 2021-09-14
- Earliest claimed: 2017-10-16
- Applicants: Mitsui High-tec, Inc.
- Inventors: Akihiro Hashimoto; Takahiro Shimizu
- Web page: https://patentgrep.com/patent/US11121610B2

## CPC

- H02K 15/026: Wound cores
- H02K 1/148: {Sectional cores (H02K1/141 takes precedence)}
- H02K 15/021: Magnetic cores
- B21D 28/22: Notching the peripheries of circular blanks, e.g. laminations for dynamo-electric machines
- H02K 1/146: {consisting of a generally annular yoke with salient poles}
- Y10T 29/49078: Laminated
- H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53})
- B21D: WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL (working or processing of wire B21F)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A method of manufacturing a laminated core includes supplying a stator material to a punching device and obtaining an electromagnetic steel plate corresponding to a rectangular processed body by punching the stator material. To obtain the electromagnetic steel plate ES, a slit is formed outside a processed body forming area in the stator material along a long side of the processed body forming area, and a center portion of the processed body forming area is punched out in a circular shape. Additionally, the processed body forming area is punched out after the slit is formed and the center portion is punched out. The laminated core is obtained by laminating and fastening a plurality of the electromagnetic steel plates.

## Claims

### Claim 1

A method of manufacturing a laminated core comprising:
supplying a workpiece plate to a die;
obtaining a rectangular processed body by punching the workpiece plate using the die; and
obtaining a laminated core by laminating and fastening a plurality of processed bodies,
wherein obtaining the rectangular processed body includes:
a slit forming step of forming a slit outside a processed body forming area in the workpiece plate along a long side of the processed body forming area, wherein the processed body forming area corresponds to an area formed as the processed body;
an inner diameter removal step of punching a center portion of the processed body forming area in a circular shape; and
a processed body removal step of punching the processed body forming area after the slit forming step and the inner diameter removal step, and
wherein in the slit forming step, the slit having six or more sides in plan view is formed.

### Claim 2

A method of manufacturing a laminated core comprising:
supplying a workpiece plate to a die;
obtaining a rectangular processed body by punching the workpiece plate using the die; and
obtaining a laminated core by laminating and fastening a plurality of processed bodies,
wherein obtaining the rectangular processed body includes:
a slit forming step of forming a slit outside a processed body forming area in the workpiece plate along a long side of the processed body forming area, wherein the processed body forming area corresponds to an area formed as the processed body;
an inner diameter removal step of punching a center portion of the processed body forming area in a circular shape; and
a processed body removal step of punching the processed body forming area after the slit forming step and the inner diameter removal step, and
wherein in the inner diameter removal step, the center portion is punched while a reinforcement member is inserted into the slit, and
wherein in the inner diameter removal step, the center portion is punched in a state where the workpiece plate is fastened by inserting a pin into each pilot hole of a plurality of pilot holes which surround the processed body forming area, while the reinforcement member is inserted into the slit.

### Claim 3 (depends on 1)

The method according to claim 1,
wherein the inner diameter removal step is performed after the slit forming step.