Molding device, metal mold, method of manufacturing magnet roll and method of magnetizing magnet roll

Patent metadata

Field	Value
Publication number	US-10698344-B2
Application number	US-201615543184-A
Country	US
Kind code	B2
Filing date	Jan 19, 2016
Priority date	Jan 28, 2015
Publication date	Jun 30, 2020
Grant date	Jun 30, 2020

Abstract

A molding device for molding a magnet roll with a profiled cross-section comprises a heating and kneading unit that supplies, to a cylindrical metal mold, a kneaded material obtained by heating and kneading a raw mixture including ferromagnetic particles and thermoplastic resin, an extrusion molding unit that molds the supplied kneaded material by the metal mold, and a magnetic field generating unit disposed at an end portion of the metal mold in a lengthwise direction that generates a magnetic field inside the metal mold, and the metal mold has a profiled C-shaped cross-section at an inlet for the kneaded material and a profiled cross-section at an outlet for the kneaded material more complex than the inlet.

First claim

The invention claimed is:

1. A molding device for molding a magnet roll with a profiled cross-section, comprising:
a heating and kneading unit that supplies, to a cylindrical metal mold, a kneaded material obtained by heating and kneading a raw mixture including ferromagnetic particles and thermoplastic resin;
an extrusion molding unit that molds the supplied kneaded material by the metal mold; and
a magnetic field generating unit disposed at an end portion of the metal mold in a lengthwise direction that generates a magnetic field inside the metal mold,
wherein the metal mold has a profiled C-shaped cross-section at an inlet for the kneaded material and a profiled C-shaped cross-section at an outlet for the kneaded material, and
wherein, in the metal mold, the cross-section at the outlet for the kneaded material has more irregularities than the cross-section at the inlet for the kneaded material.

2. The molding device according to claim 1 ,
wherein the inlet has a cross-sectional area equal to or larger than the cross-sectional area of the outlet.

3. The molding device according to claim 1 ,
wherein the outlet of the metal mold is provided with a protruding portion that protrudes in an extrusion direction so as to encircle the outlet and a flange portion that is circumferentially provided on an outer surface of the outlet.

4. The molding device according to claim 1 , further comprising:
a cooling unit that cools a molding formed of the kneaded material that has been extruded from the outlet.

5. A metal mold for extruding and molding a magnet roll, comprising:
an inlet having a profiled C-shaped cross-section;
an outlet having a profiled C-shaped cross-section; and
a diminishing-diameter portion where an internal surface progressively diminishes in diameter from the inlet having the profiled C-shaped cross-section to the outlet having the profiled C-shaped cross-section,
wherein the cross-section at the outlet has more irregularities than the cross-section at the inlet.

6. A molding device for molding a magnet roll with a profiled cross-section, comprising:
a heating and kneading unit that supplies, to a cylindrical metal mold, a kneaded material obtained by heating and kneading a raw mixture including ferromagnetic particles and thermoplastic resin;
an extrusion molding unit that molds the supplied kneaded material by the metal mold; and
a magnetic field generating unit disposed at an end portion of the metal mold in a lengthwise direction that generates a magnetic field inside the metal mold,
wherein the metal mold has a profiled C-shaped cross-section at an inlet for the kneaded material and a profiled C-shaped cross-section at an outlet for the kneaded material, and
wherein, in the metal mold, a difference between distances from an adjacent depression portion and projection portion to a central axis at the outlet for the kneaded material is larger than a difference between distances from the adjacent depression portion and projection portion to the central axis at the inlet for the kneaded material.

7. The molding device according to claim 6 ,
wherein the inlet has a cross-sectional area equal to or larger than the cross-sectional area of the outlet.

8. The molding device according to claim 6 ,
wherein the outlet of the metal mold is provided with a protruding portion that protrudes in an extrusion direction so as to encircle the outlet and a flange portion that is circumferentially provided on an outer surface of the outlet.

9. The molding device according to claim 6 , further comprising:
a cooling unit that cools a molding formed of the kneaded material that has been extruded from the outlet.

10. A metal mold for extruding and molding a magnet roll, comprising:
an inlet having a profiled C-shaped cross-section;
an outlet having a profiled C-shaped cross-section; and
a diminishing-diameter portion where an internal surface progressively diminishes in diameter from the inlet having the profiled C-shaped cross-section to the outlet having the profiled C-shaped cross-section,
wherein a difference between distances from an adjacent depression portion and projection portion to a central axis at the outlet is larger than a difference between distances from the adjacent depression portion and projection portion to the central axis at the inlet.

Assignees

• Hitachi Metals Ltd

Inventors

• Taniguchi Osamu
• Orimo Masahiko

Classifications

• H01F41/0273

  Imparting anisotropy (methods and devices for magnetising permanent magnets H01F13/003) · CPC title

• H01F7/0273

  Magnetic circuits with PM for magnetic field generation · CPC title

• G03G15/0921

  Details concerning the magnetic brush roller structure, e.g. magnet configuration · CPC title

• H01F41/0266

  Moulding; Pressing (H01F41/0273 takes precedence; hard magnetic particles H01F1/06, H01F1/11) · CPC title

• G03G15/0942 Primary

  with means for preventing toner scattering from the magnetic brush, e.g. magnetic seals · CPC title