| 摘要 |
<p>Forming hollow, box-section, frame members which include localized reinforcement. The frame members are produced by fitting a sleeve (11) about a tube (10), deforming the tube (10) and sleeve (11) to avoid the occurrence of pinching on closing of die sections about the deformed tube and sleeve in a sectional die, and then expanding the tube and sleeve in the die to form the hollow, box-section, frame member in which the sleeve (11) is mechanically locked on an inwardly offset intermediate portion (14) of the tube (10). The expansion is achieved by application of an internal pressure within the tube.</p> |
