Method for producing rare-earth magnets, and slurry application device

Patent metadata

Field	Value
Publication number	US-10854382-B2
Application number	US-201615569881-A
Country	US
Kind code	B2
Filing date	Apr 18, 2016
Priority date	Apr 28, 2015
Publication date	Dec 1, 2020
Grant date	Dec 1, 2020

Abstract

When a slurry in which a rare-earth-compound powder is dispersed is applied to sintered magnet bodies 1 and dried to apply the powder thereto, the sintered magnet bodies 1 are conveyed by a conveyer 2 and made to pass through the slurry 4 to apply the slurry to the sintered magnet bodies 1 . Furthermore, a plurality of push-up members 51 , which pass through insertion holes 22 provided in a conveyor belt 21 , and protrude above the conveyor belt, are used to temporarily push up the sintered magnet bodies 1 , and temporarily separate the conveyor belt 21 and the sintered magnet bodies 1 . As a result, the slurry can be efficiently applied, even mass production can be suitably dealt with, and the slurry can be uniformly and reliably applied to the entire surface of each of the sintered magnet bodies.

First claim

The invention claimed is:

1. A method for producing rare earth magnet comprising the steps of applying a slurry of a powder in a solvent to a sintered magnet body of R 1 —Fe—B composition, wherein R 1 is one or more elements selected from Y, Sc and rare earth elements, the powder containing one or more compounds selected from an oxide, fluoride, oxyfluoride, hydroxide and hydride of R 2 wherein R 2 is one or more elements selected from Y, Sc and rare earth elements, drying the slurry to coat the sintered magnet body with the powder, and heat treating the coated magnet body for causing R 2 to be absorbed in the sintered magnet body, the method further comprising the steps of:
providing a slurry tank filled with the slurry, a conveyor having a conveyer belt for conveying the sintered magnet body, a plurality of insertion holes perforated in the conveyer belt, and a plurality of column or rod shaped push-up members,
arranging the conveyor and the plurality of column or rod shaped push-up members so that i) the conveyer belt forms a horizontal track which goes through the slurry in the slurry tank, and ii) each of the column or rod shaped push-up members is vertically arranged to move up and down through the insertion holes of the conveyor belt, and iii) the plurality of column or rod shaped push-up members are disposed under the conveyor belt and moved in a horizontal direction parallel to the horizontal track of the conveyor belt within the slurry tank,
moving the conveyor belt and the plurality of column or rod shaped push-up members so that the plurality of column or rod shaped push-up members are moved in a same direction as the conveyor belt and are moved beneath the conveyor belt within the slurry tank,
placing and conveying the sintered magnet body on the conveyor belt by the conveyor so as to pass through the slurry in the slurry tank, for thereby immersing the sintered magnet body in the slurry and applying the slurry to the sintered magnet body, and
temporarily pushing up the sintered magnet body on the conveyor belt during the immersion duration within the slurry tank, by the plurality of column or rod shaped push-up members which protrude from the conveyor belt through the insertion holes of the conveyor belt, such that the sintered magnet body is lifted up and separated from an upper surface of the conveyor belt and then moved down onto the prior position on the upper surface of the conveyor belt without turning over.

2. The rare earth magnet producing method of claim 1 wherein the conveyor belt is a mesh belt.

3. The rare earth magnet producing method of claim 1 or 2 wherein the push-up member is a thin rod having a diameter of 0.5 to 5 mm.

4. The rare earth magnet producing method of claim 1 , further comprising the step of conveying the sintered magnet body which has passed though the slurry and had the slurry applied thereto, as such by the conveyor so as to pass through a residual droplet removing zone and a drying zone in sequence for thereby removing any residual droplets on the sintered magnet body surface and drying.

5. The rare earth magnet producing method of claim 1 wherein the plurality of column or rod shaped push-up members are connected by a push-up circular belt.

6. The rare earth magnet producing method of claim 1 wherein a cam member is disposed below the conveyor belt, and
the cam member is arranged so that when the push-up members are passing beneath the conveyor belt, the push-up members come in contact with the cam member, thereby pushing up the push-up members to protrude from the conveyor belt and separate the sintered magnet body from the surface of the conveyor belt.

Assignees

• Shinetsu Chemical Co

Inventors

• Kuribayashi Yukihiro
• Kamiya Shogo
• Maegawa Harukazu
• Tanaka Shintaro

Classifications

• B22F3/00

  Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor {; Presses and furnaces} · CPC title

• B05C3/10

  the articles being moved through the liquid or other fluent material (conveying articles through baths B65G, e.g. B65G49/02) · CPC title

• B05C13/02

  for particular articles · CPC title

• H01F1/0577

  sintered · CPC title

• B05D5/12

  to obtain a coating with specific electrical properties · CPC title