PURPOSE: To allow drawing, bulging, etc., under an extra-high pressure with good formability by joining an upper half frame and lower half frame which are respectively semicircular to constitute a spherical outer frame.
CONSTITUTION: A blank W is installed to a die 90 of a lower frame 3. While a liquid is filled into a liquid pressure dome 9 through a liquid pressure port 91 from a confronted liquid pressure supply and control device A, the liquid is supplied into a blank holding cylinder 5 via a liquid pressure port 51 from a liquid pressure supply and control device B for blank holding. A mounting block 60 is lowered in a cavity 20 for guide in the upper frame 2 by the extension of a ram 40 when an inner cylinder 4 is actuated in the state of crimping the peripheral part of the blank W by said holder and a die 90. A punch 6, therefore, descends in the cavity 32 and comes into contact with the blank W, thereby pushing the blank into the dome 9. The generation of the counter liquid pressure is obviated and the pressure is increased in this way so that the blank W is wound around the punch 6. The counter liquid pressure acts directly on the blank W and since the pressure of the blank holding cylinder 5 can be regulated freely, the good drawing property is obtd. and the intricate forming is possible as well.
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