PURPOSE: To perform string extrusion in an optional shape in a short time precisely by arranging and retaining segmental dies at the outside of a cylindrical shell, and inserting a pressing rod equipped with an elastic body into the cylindrical shell and then applying an axial load.
CONSTITUTION: For the string extrusion of a cylindrical shell 1, a pressing rod 7 equipped with an elastic body 3 of annular rubber, etc., is inserted into the cylindrical shell 1. Sectional dies 2 each having a prescribed string shape worked in the internal surface are set at the outside of the cylindrical shell 1 facing the elastic body 3 and retained with a retaining rind 9. In this state, highly pressurized oil is fed from a hydraulic cylinder 6 to apply an axial load to the pressing rod 7, and thus the elastic body 3 is compressed to spread in radius directions. Consequently, internal pressure is allowed to operate on the internal surface of the cylindrical shell 1 in radius directions, thereby extruding the cylindrical shell 1 in the shape of grooves worked in the internal circumferences of the segmental dies 2. This method realizes excellent string extrusion in an optional shape.
SHIMAGUCHI TAKASHI
YOSHITOMI YUUJI
| JPS55165233A | 1980-12-23 | |||
| JPS4857877A | 1973-08-14 | |||
| JPS55141343A | 1980-11-05 |