Pressure forming and piercing a hollow body
AssigneeSchafer Hydroforming GmbH & Co.
InventorsAugust Wilhelm Schafer, Hans Werner Scholz, Adolf Handel
Life of this patent
Estimating the term…
Abstract
A shaped and pierced hollow workpiece is made by first confining a hollow metal blank in a cavity of a die which has an inner surface and is formed with a lateral compartment. The blank is internally pressurized to press it outward against the inner surface of the cavity while forming at the compartment an outwardly projecting bulge. A tool is pressed against an outer surface of the bulge and the bulge is pressed inward so as to at least partially to invert it and press a central portion of the bulge against an opposite inside wall of the blank. A hole is then machined through the blank where the central portion of the bulge engages the opposite inside wall.
Claims12
A method of making a shaped and pierced hollow workpiece, the method comprising the steps of sequentially:
- confining a hollow metal blank in a cavity of a die, the cavity having an inner surface and being formed with a lateral compartment;
- internally pressurizing the blank and thereby pressing it outward against the inner surface of the cavity while forming at the compartment an outwardly projecting bulge;
- pressing a tool against an outer surface of the bulge and pressing the bulge inward so as to at least partially invert the bulge and press a central portion of the bulge against an opposite inside wall of the blank;
- and
- forming a hole through the blank where the central portion of the bulge engages the opposite inside wall.
An apparatus for making a shaped and pierced hollow workpiece, the apparatus comprising:
- a die adapted to hold a hollow blank and formed with a cavity having an inner surface and a lateral compartment;
- means for internally pressurizing the blank in the cavity and thereby pressing it outward against the inner surface of the cavity while forming at the compartment an outwardly projecting bulge;
- a tool engageable in the compartment against an outer surface of the bulge;
- actuator means connected to the tool for pressing the bulge inward so as to at least partially invert the bulge and press a central portion of the bulge against an opposite inside wall of the blank;
- and
- means for forming a hole through the blank where the central portion of the bulge engages the opposite inside wall.
Dependencies are inferred from the claim text.