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US 6,332,932 B1Granted
Punch, powder pressing apparatus and powder pressing method
AssigneeSumitomo Special Metals Co., Ltd.
InventorsSeiichi Kohara, Shinji Kidowaki
Life of this patent
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AssigneeSumitomo Special Metals Co., Ltd.
InventorsSeiichi Kohara, Shinji Kidowaki
Estimating the term…
A powder pressing apparatus comprises a die having a through hole, an upper punch and a lower punch. At least one of the upper and lower punches has a punching surface having an edge portion provided with a projection. The projection has a tip chamfered by a width not greater than 0.5 mm. The punching surface has a slope having a surface roughness Ra not greater than 1.0 μm. A rare-earth alloy powder is fed into a cavity formed in the through hole of the die. The rare-earth alloy powder in the cavity is oriented by magnetic field, and pressed by using the upper and lower punches. The upper punch and the lower punch are brought closest to each other at a minimum distance not smaller than 1.7 mm during the pressing. An obtained compact is used for manufacture of a sintered body and a voice coil motor.
A compact manufactured by a powder pressing method using a punch and a die, the punch including a punching surface for pressing the rare-earth alloy powder, the punching surface including an edge portion provided with a projection having a tip chamfered by a width of not greater than 0.5 mm, the die including a through hole for insertion by the punch, the method comprising:
A compact manufactured by a powder pressing method using a punch and a die, the punch including a punching surface for pressing the rare-earth alloy powder, the punching surface including a projection provided with a slope having a surface roughness Ra not greater than 1.0 μm, the die including a through hole for insertion by the punch, the method comprising:
A compact made of a rare-earth alloy powder, comprising:
A compact made of a rare-earth alloy powder, comprising:
A sintered body made of a rare-earth alloy powder, comprising:
A sintered body made of a rare-earth alloy powder, comprising:
A voice coil motor using a sintered body of a rare-earth alloy powder, the sintered body comprising:
A voice coil motor using a sintered body of a rare-earth alloy powder, the sintered body comprising:
Dependencies are inferred from the claim text.