| 摘要 |
A method for forming a closed channel structural member (10) having a central portion that is enlarged relative to the end portions thereof is disclosed. Initially, a tube is formed in a hydroforming die (11) to have a desired shape that is preferably characterized by a relatively small diameter central portion extending between a pair of relatively large diameter end portions (15). Next, the tube (10) is divided into two pieces in any conventional manner, such as by cutting, to provide two tube sections (10a) and (10b). Each of the two tube sections (10a) and (10b) is then oriented in the opposite direction such that the relatively large end portions (15) of the tube are disposed adjacent to one another. Lastly, the relatively large end portions (15) are joined together in any conventional manner, such as by butt welding, to form a unitary member (30) characterized by a relatively large diameter central portion extending between a pair of relatively small diameter end portions (16). In an alternative embodiment, a pair of tubes (50) and (60) are initially formed in the same manner. Each of the tubes is divided into two pieces (50a), (50b) and (60a), (60b). Then, the first section (60a) of the first tube (50) is aligned with the second section (60b) of the second tube (60), and the first section (60a) of the second tube (60) is aligned with the second section (50b) of the first tube (50). Then, each of the four tube sections (50a), (60b) and (60a), (50b) is oriented in the opposite direction, and the adjacent end surfaces (51), (61) of the tube sections are joined together to form a pair of unitary members (70) and (80). The unitary members (70) and (80) can be used as components, such as the side rails, of a vehicle body and frame assembly (40). |
