Powder compacting apparatus and method of making rare-earth alloy magnetic powder compact
AssigneeSumitomo Special Metals Co., Ltd.
InventorsShuichi Okuyama, Tsutomu Harada, Takashi Tajiri
Life of this patent
Estimating the term…
Abstract
The present invention provides a powder compacting apparatus including: a die having a through hole forming a cavity; a first punch and a second punch for pressing a rare-earth alloy magnetic powder filled in the cavity; and a magnetic field generator for applying an orientation magnetic field parallel to a pressing direction through the rare-earth alloy magnetic powder in the cavity, wherein at least one of the first and second punches and has a curved pressing surface, and the pressing surface is given a shape such as to suppress the movement of particles of the rare-earth alloy magnetic powder along the pressing surface during the pressing step.
Claims29
A powder compacting apparatus for pressing powder in a pressing process, comprising:
- a die having a through hole forming a cavity;
- an upper punch and a lower punch for pressing a rare-earth alloy magnetic powder filled in said cavity in a pressing direction;
- and
- magnetic field generation means for applying an orientation magnetic field parallel to said pressing direction through the rare-earth alloy magnetic powder in said cavity, wherein:
- said upper punch and said lower punch have a convex curved pressing surface and a concave curved pressing surface, respectively;
- at least one of said convex curved pressing surface and a concave curved pressing surface is shaped to suppress movement of particles of the rare-earth alloy magnetic powder along said pressing surface during said pressing process.
A method of making a rare-earth alloy magnetic powder compact, comprising the steps of:
- providing a powder compacting apparatus;
- and
- using said powder compacting apparatus to compact a rare-earth alloy magnetic powder, wherein
- said powder compacting apparatus for pressing powder in a pressing process, comprising:
- a die having a through hole forming a cavity;
- a first punch and a second punch for pressing a rare-earth alloy magnetic powder filled in said cavity in a pressing direction;
- and
- magnetic field generation means for applying a orientation magnetic field parallel to said pressing direction through the rare-earth alloy magnetic powder in said cavity, wherein;
- at least one of said first and second punches has a curved pressing surface;
- and
- said pressing surface is shaped to suppress movement of particles of the rare-earth alloy magnetic powder along said pressing surface during said pressing process.
A method of producing a rare-earth magnet, comprising the steps of:
- providing a powder compacting apparatus;
- using said powder compacting apparatus to form a compact of a rare-earth alloy magnetic powder;
- and
- making a permanent magnet from the compact, wherein
- said powder compacting apparatus for pressing powder in a pressing process, comprising:
- a die having a through hole forming a cavity;
- a first punch and a second punch for pressing a rare-earth alloy magnetic powder filled in said cavity in a pressing direction;
- and
- magnetic field generation means for applying a orientation magnetic field parallel to said pressing direction through the rare-earth alloy magnetic powder in said cavity, wherein;
- at least one of said first and second punches has a curved pressing surface;
- and
- said pressing surface is shaped to suppress movement of particles of the rare-earth alloy magnetic powder along said pressing surface during said pressing process.
The powder pressing die set, comprising an upper punch and a lower punch having a convex curved pressing surface and a concave curved pressing surface, respectively, for pressing powder particles in said die set during a pressing process;
- wherein at least one of said convex curved pressing surface and a concave curved pressing surface is shaped to suppress movement of powder particles along the at least one pressing surface during said pressing process.
A rare-earth magnet formed from being pressed in a direction, wherein a pattern is formed on a surface thereof, said pattern including at least one of concave portions and convex portions extending in a direction generally parallel to a reference plane that is perpendicular to said pressing direction.
A rare-earth magnet formed by pressing magnet powder in a pressing direction, said magnet comprising:
- a surface including a plurality of parallel minute surfaces extending in a direction generally parallel to a reference plane that is perpendicular to said pressing direction,
- each of said minute surfaces is separated from adjacent minute surfaces by a step.
A rare-earth magnet formed by pressing magnet powder in a pressing direction, comprising a surface including a plurality of strip-shaped flat surfaces extending in a direction generally parallel to a reference plane that is perpendicular to a pressing direction.
A powder compacting apparatus for pressing powder in a pressing process, comprising:
- a die having a through hole forming a cavity;
- a first punch and a second punch for pressing a rare-earth alloy magnetic powder filled in said cavity in a pressing direction;
- and
- magnetic field generation means for applying an orientation magnetic field parallel to said pressing direction through the rare-earth alloy magnetic powder in said cavity, wherein:
- at least one of said first and second punches has a curved pressing surface;
- said pressing surface is shaped to suppress movement of particles of rare-earth alloy magnetic powder along said pressing surface during said pressing process;
- said pressing surface comprises parallel minute surfaces extending in a direction generally parallel to a reference plane that is perpendicular to said pressing direction;
- and
- each of said minute surfaces is separated from adjacent minute surfaces by a step.
A powder compacting apparatus for pressing powder in a pressing process, comprising:
- a die having a through hole forming a cavity;
- a first punch and a second punch for pressing a rare-earth alloy magnetic powder filled in said cavity in a pressing direction;
- and
- magnetic filed generation means for applying an orientation magnetic field parallel to said pressing direction through the rare-earth alloy magnetic powder in said cavity, wherein:
- at least one of said first and a second punches has a curved pressing surface;
- said pressing surface is shaped to suppress movement of particles of the rare-earth alloy magnetic powder along said pressing surface during said pressing process;
- and
- said pressing surface comprises a non-directional concave/convex portions formed randomly.
Dependencies are inferred from the claim text.