Method for manufacturing iron core

Patent metadata

Field	Value
Publication number	US-11298739-B2
Application number	US-201916552135-A
Country	US
Kind code	B2
Filing date	Aug 27, 2019
Priority date	Sep 20, 2018
Publication date	Apr 12, 2022
Grant date	Apr 12, 2022

Abstract

Provided is a method for manufacturing an iron core that enables reduction of variations in dimension of a plurality of metal plates that occur during pressing of the laminate of these metal plates. The method includes: a laminate preparation step of stacking a plurality of metal plates to prepare a laminate; a pressing step of giving a temperature gradient to the laminate and pressing the laminate with a pressing machine having a punch and a die; and a temperature-gradient removal step of removing the temperature gradient from the laminate. The pressing step gives the temperature gradient to the laminate so that the temperature rises from the punch-side to the die-side in the stacking direction of the laminate.

First claim

What is claimed is:

1. A method for manufacturing an iron core operatively associated with a press device comprising a punch and a die, comprising steps of:
a laminate preparation step of stacking a plurality of metal plates for iron core to prepare a laminate;
a pressing step of giving a temperature gradient to the laminate and pressing the laminate with the punch device; and
a temperature-gradient removal step of removing the temperature gradient from the laminate,
wherein
the pressing step gives the temperature gradient to the laminate so that a temperature rises from a part close to the punch to a part close to the die in a stacking direction of the laminate.

2. The method for manufacturing the iron core according to claim 1 , wherein the metal plates for iron core include amorphous metal.

3. The method for manufacturing the iron core according to claim 1 , wherein the die includes a heater, and
the pressing step gives the temperature gradient to the laminate with the heater.

4. The method for manufacturing the iron core according to claim 1 , wherein the temperature gradient is controlled based on a linear expansion coefficient of the metal plates for iron core and a contact area between the metal plate for iron core and an upper face of the die.

5. The method for manufacturing the iron core according to claim 1 , wherein the temperature-gradient removal step returns a temperature of the laminate to a room temperature.

Assignees

• Toyota Motor Co Ltd

Inventors

• Shikii Kenta
• Ishikura Hiroshi

Classifications

• B21D37/16

  Heating or cooling · CPC title

• B21D24/02

  Die-cushions · CPC title

• B21D28/22 Primary

  Notching the peripheries of circular blanks, e.g. laminations for dynamo-electric machines · CPC title

• B21D22/02 Primary

  Stamping using rigid devices or tools · CPC title

• H02K15/02

  of stator or rotor bodies · CPC title