Soft magnetic material, dust core, transformer core, motor core, and method for producing dust core

• US 20060237096A1
• Filed: 07/30/2004
• Published: 10/26/2006
• Est. Priority Date: 07/30/2003
• Status: Abandoned Application

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.), Sumitomo Electric Industries Limited (Sumitomo Corporation)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.), Sumitomo Electric Industries Limited (Sumitomo Corporation)
• Inventors: Shimada, Yoshiyuki, Shiga, Ryuji, Toyoda, Haruhisa, Ueda, Kazuhiko, Tanaka, Shohzoh, Kugai, Hirokazu
• Application Number:
  US10/565,939
• Publication Number:
  US 20060237096A1
• Time in Patent Office: Days
• US Class Current: 148/104
• CPC Class Codes: H01F 1/26 by macromolecular organic substances
• CPC Class Codes: H01F 41/0246 Manufacturing of magnetic circuits by moulding or by pressing powder magnetic cores made by moulding or by pressing powder H01F27/255; soft magnetic particles H01F1/20, H01F1/36

Abstract

A soft magnetic material includes a plurality of composite magnetic particles each having a metal magnetic particle and an insulating film surrounding a surface of the metal magnetic particle, and an organic substance joining the plurality of composite magnetic particles together. The organic substance has a deflection temperature under load of not more than 100° C. With this structure, the soft magnetic material can obtain a desired magnetic property.

Claims

1. A soft magnetic material, comprising:

a plurality of composite magnetic particles each having a metal magnetic particle and an insulating film surrounding a surface of said metal magnetic particle, and

an organic substance joining said plurality of composite magnetic particles together,

wherein said organic substance has a deflection temperature under load of not more than 70°

C., and a magnetic flux density when a magnetic field of 100 (oersted) is applied to a dust core fabricated using the soft magnetic material is not less than 1.4 (T;

tesla).

2. The soft magnetic material according to claim 1, wherein a ratio of said organic substance to the soft magnetic material is not less than 0.3% by mass and not more than 0.5% by mass.

3. A dust core using the soft magnetic material according to claim 2, wherein the dust core is formed as a hollow cylinder having a height H and a wall thickness T, said height H being not less than 25 mm and a ratio H/T of said height H to said wall thickness T being not less than 3.

4. The dust core according to claim 3, wherein said hollow cylinder has an outer diameter of not less than 30 mm.

5. A linear motor core using the dust core according to claim 3.

6. A transformer core using the dust core according to claim 3.

7. A method of manufacturing the dust core according to claim 3, comprising the steps of:

preparing a mold having an inner wall and defining a compression space at a location surrounded by said inner wall, and

putting the soft magnetic material into said compression space without applying a lubricant to said inner wall, and compression molding the soft magnetic material.

8. The method of manufacturing the dust core according to claim 7, further comprising the step of performing thermal treatment after said step of compression molding, at a temperature of more than a glass transition temperature of said organic substance and not more than a thermal decomposition temperature of said organic substance.

9-15. -15. (canceled)