초록 ▼

A method and apparatus for forming complex shaped frame members from a tubular blank where the blank is transferred from station to station and various tooling are performed on the blank at each station. For example, at a first station the blank is expanded into a tube having a varying cross-section

A method and apparatus for forming complex shaped frame members from a tubular blank where the blank is transferred from station to station and various tooling are performed on the blank at each station. For example, at a first station the blank is expanded into a tube having a varying cross-section throughout the length of the tube by applying pressure to the interior of the tube and compressive force to the opposed ends of the tube preferably simultaneously. At another station, the expanded tube is preformed by introducing a bend therein. The bend in the preformed tube is then increased at another station. While the expanded tube is being preformed and bent, the flow of material into the die cavity at those stations is controlled to reduce the amount of folding that may occur. The shape of the frame member is finished at another station by introducing a lateral bend and varying the cross-sectional configuration of the bent tube. Holes may then be pierced into the finished frame member at another station by pressurizing the interior of the frame member with hydraulic fluid and striking the frame member with a piercing punch. Final stations crop the ends and flush the interior of the frame member before it is unloaded for further transport.

대표청구항 ▼

[ What is claimed is:] [1.] A method of forming in a series of die cavities a frame member having an interior, an elevational view configuration and a cross-sectional view configuration from a tubular blank material having opposed ends, a blank wall and a blank interior comprising the steps of:expan

[ What is claimed is:] [1.] A method of forming in a series of die cavities a frame member having an interior, an elevational view configuration and a cross-sectional view configuration from a tubular blank material having opposed ends, a blank wall and a blank interior comprising the steps of:expanding a portion of the blank in a first die cavity to form a bulged tube comprising the steps of:a) placing the blank in the first die cavity;b) applying internal pressure within the blank interior to stabilize the blank wall; andc) applying external pressure to the opposed ends of the blank to allow material to flow into the first die cavity to form the bulged tube;bending the bulged tube in a second die cavity in a first plane to form a preformed tube comprising the steps of:a) placing the bulged tube in the die cavity;b) pressurizing the bulged tube in the die cavity; andc) bending the bulged tube to form the preformed tubebending the preformed tube in a die cavity in a second plane comprising the steps of:a) placing the preformed tube in the die cavity;b) pressurizing the preformed tube in the die cavity; andc) bending the preformed tube in the die cavity creating the frame member by altering the elevational view configuration and the cross-sectional view configuration of the expanded tube.