| 摘要 |
The method for hydroforming an angled tubular part having portions with first and second axes disposed at an angle of at least 30ºC comprises; disposing an angled metal tubular blank (70) within a generally correspondingly angled die cavity (12), the tubular blank having an exterior surface, wherein at an angled portion of the tubular blank, the exterior surface has a concave surface portion (75) and a convex surface portion (76) on generally opposite sides of the tubular blank; sealing opposite ends of the tubular blank; providing high pressure fluid to an interior of the tubular blank; expanding the blank into conformity with surfaces defining the die cavity as a result of the high pressure fluid; applying force to at least one end of the tubular blank so as to create longitudinal flow of metal material within the tubular blank to maintain a wall thickness of the blank within a predetermined range. The method is characterised in that a greater amount of force is applied to a portion of the tubular blank which is longitudinally aligned with the convex surface portion of the tubular blank in comparison with the amount of force applied to a portion of the tubular blank which is longitudinally aligned with the concave surface portion of the tubular blank. This is to create a greater amount of flow of metal material toward portions of the tubular blank adjacent the convex surface portion, so as to inhibit wrinkle formation at the portions of the tubular blank adjacent the concave surface portion. The hydroforming system includes a pair of hydraulic ram assemblies (16 and 18) arranged to engage opposite ends of the tubular metal blank. The tube end engaging structures provide a port through which the pressurised fluid can be provided to the interior of the blank.
|
