Method of and apparatus for forging hollow blank member
AssigneeJidosha Kiki Co., Ltd.
InventorsKazuhisa Kumekawa, Shinichi Ando
Life of this patent
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Abstract
A method of and an apparatus for shaping a hollow blank member by a forging operation is provided. The interior of a hollow blank member is filled with a liquid pressure medium which is enclosed therein in sealed condition. An external pressure is applied to the hollow blank member, and the pressure of the pressure medium is maintained as an internal pressure which opposes the external pressure, and part of the pressure medium is discharged externally while applying a desired plastic deformation to the hollow blank member.
Claims7
A method for forging a hollow blank member comprising the steps of filling the hollow interior of a hollow blank member with a liquid pressure medium and enclosing the latter in sealed condition therein, applying an external pressure to the hollow blank member when the latter is filled with the pressure medium, allowing part of the pressure medium to be discharged gradually so as to maintain the pressure of the pressure medium as an internal pressure which opposes the external pressure, and applying a desired plastic deformation to the hollow blank member while the pressure medium is being discharged.
An apparatus for forging a hollow blank member comprising a lower die having a recess formed therein which receives a hollow blank member so as to block its opening, an upper die adapted to be fitted into the recess, the lower die being formed with a passage which allows the internal space of the hollow blank member which is received within the lower die to communicate with the exterior, and means disposed within the passage for restricting the flow rate of the pressure medium enclosed within the hollow blank member and discharged as a result of the application of the external pressure by the upper die, whereby said means maintains an internal pressure.
Dependencies are inferred from the claim text.