Kobe Steel, Ltd.

Tatsuo Yamasaki

Yoshihiro Yamaguchi

Tomiharu Matsushita

Masao Nishihara

Kunihiko Nishioka

Masataka Noguchi

Hideaki Ide

Yuuzi Nakahara

Masataka Nogushi

A method and machine for use in hydrostatic extrusion wherein a portion of an elastic-plastic viscous pressure medium is introduced into the rear portion of a container, with the rear end thereof being sealed in a fluid tight fashion. The pressure medium being of such a nature that it has a high viscosity and cannot flow by itself. Subsequently, a billet is charged into the container and then a die is mounted in the container at the forward end thereof. The aforesaid pressure medium is caused to fill around the outer circumferential surface of the billet. In this respect, a high pressure seal is provided for the junctions between the die and the forward end of the container and between the die and the forward end of the billet before the pressure medium flows out of the container in a practically negligible small amount, immediately after which a pressure stem is pushed into the container from the rear end thereof, thus proceeding with the hydrostatic extrusion.

Machine for use in hydrostatic extrusion

A hydrostatic extrusion method and apparatus for the extrusion of tubes is disclosed wherein the simplified structure of the nose or tip portion of the billet and the cooperating surfaces of the die defining the die cavity and those of the mandrel facilitate an improved initial sealing among the associated surfaces of the die, billet and mandrel. Such an initial sealing is effected between such interfaces of the members and billet at a point which is located substantially rearwardly from the position at which the actual extrusion to the final tubular configuration occurs between the bearing portion of the die and the cooperating sizing portion of the mandrel. Such structure and method permits the extrusion of tubes having walls of asymmetric or non-circular configurations in cross section, even those of complex configurations. In order to further enhance the efficacies of the present invention, the mandrel is provided with a head portion which may be replaced, or exchanged as desired, and a position-aligning member is associated with the mandrel in order to maintain the proper orientation of the mandrel relative to the die. The mandrel may also have a specifically designed configuration in order to provide the inner surface of the tube extruded with a gloss finish.

Hydrostatic extrusion method and apparatus

Method and machine for use in hydrostatic extrusion

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Kobe, Japan

Tatsuo Yamasaki