Apparatus and method for forming and hydropiercing a tubular frame member

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;
• c) 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;
• c) gripping the opposed ends of the tube to control the material flow;
• and
• d) bending the bulged tube to form the preformed tube
• bending the preformed tube in a third die cavity in a second plane comprising the steps of:
• a) placing the preformed tube in the third die cavity;
• b) pressurizing the preformed tube in the third die cavity;
• and
• c) bending the preformed tube in the third die cavity
• creating the frame member by altering the elevational view configuration and the cross-sectional view configuration of the bulged tube.

A method of forming a frame member from a tubular blank having opposed ends and an interior comprising the steps of:

• placing the blank in an open first die cavity, said first die cavity defining an expanded tube;
• closing the first die cavity;
• applying hydraulic pressure to the interior of the blank and force to the opposed ends of the blank to cause the blank to expand into the first die cavity and create an expanded tube;
• removing the force and pressure applied to the expanded tube;
• transferring the expanded tube from the first cavity to an open second die cavity, said second die cavity defining the frame member having a varying elevational configuration and a varying cross-sectional configuration;
• closing the second die cavity;
• applying hydraulic pressure above the material yield limit of the expanded tube to the interior of the expanded tube to form the frame member;
• removing the internal pressure;
• and
• removing the frame member from the second die cavity.

A method of forming a frame member from a tubular blank having opposed ends and an interior comprising the steps of:

• placing the blank in an open first die cavity, said first die cavity defining an expanded tube;
• closing the first die cavity;
• applying hydraulic pressure to the interior of the blank and simultaneously applying force to the opposed ends of the blank to place the blank under compression to create an expanded tube;
• removing the force and pressure applied to the expanded tube;
• transferring the expanded tube from the first die cavity to an open second die cavity, said second die cavity defining a bent tube member;
• forming a bent tube by applying hydraulic pressure below the yield limit of the expanded tube to the interior of the expanded tube as the second die cavity is closed around the expanded tube;
• removing the bent tube from the second die cavity;
• placing the bent tube in a third die cavity, said third die cavity defining the frame member having a varying elevational configuration and varying cross-sectional configuration;
• applying hydraulic pressure above the material yield limit of the expanded tube to the interior of the bent tube to create a frame member;
• removing the internal pressure;
• and
• removing the frame member from the third die cavity.

An apparatus for forming a frame member from a tubular blank having opposed ends and an interior comprising:

• a first station providing a first die cavity with a center, a pair of seals at each end of the first die cavity, the seals being capable of delivering hydraulic fluid to the interior of the blank, means for translating the pair of seals towards the center of the die cavity wherein the blank is placed in the first die cavity, the blank being greater in length than the die cavity so that the pair of seals are then translated toward the die cavity so that they engage the opposed ends of the blank and hydraulic fluid is then delivered to the interior of the tube thereby pressurizing the interior of the blank, the seals continuing to translate towards the center of the die cavity thereby placing the blank under compression;
• a second station providing a mutually cooperating punch and die, a pair of seals at each end of the punch and die, the seals being capable of delivering hydraulic fluid wherein the tube from the first station is delivered to the second station and the interior or the tube is pressurized by engaging the seals with the ends of the tube and delivering hydraulic fluid to the interior of the tube while the tube is being compressed between the punch and die to create a bent tube;
• and
• a third station providing a mutually cooperating punch and die, a pair of seals at each end of the punch and die, the seals being capable of delivering hydraulic fluid wherein the tube from the second station is delivered to the third station and the interior of the tube is pressurized by engaging the seals with the ends of the tube and delivering hydraulic fluid to the interior of the tube while the tube is compressed between the punch and die to form a frame member having the desired elevational view configuration and the desired varying cross-sectional view configuration.