(19)
(11) EP 1 162 014 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
24.07.2002 Bulletin 2002/30

(43) Date of publication A2:
12.12.2001 Bulletin 2001/50

(21) Application number: 01304835.0

(22) Date of filing: 01.06.2001
(51) International Patent Classification (IPC)7: B21J 5/12, B21J 5/04, B21C 23/00, B21C 23/10, B21K 1/12, B21K 1/30
(84) Designated Contracting States:
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR
Designated Extension States:
AL LT LV MK RO SI

(30) Priority: 09.06.2000 JP 2000173006

(71) Applicant: Aida Engineering Ltd.
Sagamihara-shi, Kanagawa 229-1181 (JP)

(72) Inventors:
  • Kanamaru, Hisanobu
    Sagamihara-shi, Kanagawa 229-1181 (JP)
  • Kobayashi, Kazub
    Sagamihara-shi, Kanagawa 229-1181 (JP)

(74) Representative: Shelley, Mark Raymond et al
K R Bryer & Co., 7 Gay Street
Bath BA1 2PH
Bath BA1 2PH (GB)

   


(54) Pressure controlled fluid pressure extrusion method


(57) The lower part of a material blank to be molded forms a lower seal (9) with a die (2). A punch (3) applying a molding force to the material forms an upper seal (7) with the perimeter of the die. The space between the upper and lower seals (9) forms a pressure chamber (6) that is filled with a fluid. As the punch descends into the die, the fluid is pressurized. The lower seal (9) is a complete seal to prevent leakage of fluid into the die. The upper seal is given a clearance with the die that permits controlled leakage of fluid therepast at a rate that limits the maximum pressure in the pressure chamber while permitting the development of an adequate pressure on the material being molded.






Search report