Patents Assigned to Tokyo Seitan Inc.
  • Patent number: 6511560
    Abstract: A thin, forged magnesium alloy casing is integrally constituted by a thin plate with projections on either or both surfaces, and the thin plate is as thin as about 1.5 mm or less. The thin forged casing can be produced by (a) carrying out a first forging step for roughly forging a magnesium alloy plate to form an intermediate forged product under the conditions of a preheating temperature of the magnesium alloy plate of 350-500° C., a die temperature of 350-450° C., a compression pressure of 3-30 tons/cm2, a compressing speed of 10-500 mm/sec. and a compression ratio of 75% or less; and (b) carrying out a second forging step for precisely forging the intermediate forged product under the conditions of a preheating temperature of the intermediate forged product of 300-500° C., a die temperature of 300-400° C., a compression pressure of 1-20 tons/cm2, a compressing speed of 1-200 mm/sec., and a compression ratio of 30% or less.
    Type: Grant
    Filed: April 16, 2001
    Date of Patent: January 28, 2003
    Assignees: Tokyo Seitan Inc., Sony Corporation
    Inventors: Isao Seki, Shigeo Hama, Shigehiro Taniike, Fukashi Watanabe, Masahiko Kakizaki, Shinji Seki
  • Patent number: 6316129
    Abstract: A thin, forged magnesium alloy casing is integrally constituted by a thin plate with projections on either or both surfaces, and the thin plate is as thin as about 1.5 mm or less. The thin forged casing can be produced by (a) carrying out a first forging step for roughly forging a magnesium alloy plate to form an intermediate forged product under the conditions of a preheating temperature of the magnesium alloy plate of 350-500° C., a die temperature of 350-450° C., a compression pressure of 3-30 tons/cm2, a compressing speed of 10‥500 mm/sec. and a compression ratio of 75% or less; and (b) carrying out a second forging step for precisely forging the intermediate forged product under the conditions of a preheating temperature of the intermediate forged product of 300-500° C., a die temperature of 300-400° C., a compression pressure of 1-20 tons/cm2, a compressing speed of 1-200 mm/sec., and a compression ratio of 30% or less.
    Type: Grant
    Filed: March 24, 1999
    Date of Patent: November 13, 2001
    Assignees: Tokyo Seitan Inc., Sony Corporation
    Inventors: Isao Seki, Shigeo Hama, Shigehiro Tanike, Fukashi Watanabe, Masahiko Kakizaki, Shinji Seki