Showing papers on "Hydroforming published in 1995"

Extended jacket end, double expansion hydroforming

Abstract: Hydroforming double wall tubular stock into an air gap tubular element comprising providing a plural wall tubular workpiece having at least an inner wall liner and an outer wall jacket having adjacent open axial ends, causing at least one of the jacket ends to extend axially beyond the adjacent liner end and to be flared outwardly, placing the workpiece into a first mold cavity of a size and configuration to result in the desired size and configuration of the liner, sealing the open ends of said liner, injecting hydroforming fluid into said liner to fill it and applying pressure thereto to expand the liner and jacket in the first mold cavity, releasing the pressure, placing the workpiece in a second mold cavity of a size and configuration desired for the jacket on a resulting air gap tubular element, providing hydroforming end closures to seal off the jacket ends, at least one of the end closures having an annular shoulder aligned with the flared extended jacket end radially outwardly offset from the adjacent liner end, pressing the annular shoulder directly against the flared jacket end to seal the flared jacket end between the shoulder and an anvil surface, injecting fluid into the workpiece to fill it and applying pressure to expand only the jacket.

Apparatus for hydroforming a vehicle manifold

Abstract: A hydroforming process and apparatus for manufacturing components of a vehicle exhaust or intake manifold. The hydroforming process is utilized to form a tubular member to the desired configuration for use in a manifold. The tubular member is loaded into a hydroform press and filled with a suitable liquid. The liquid within the tube is pressurized in order to maintain a predetermined internal fluid pressure which prevents collapse and crimping of the tube during forming. The hydroform press includes two sets of dies to form a compound bend in the pressurized tube. Upper and lower dies close on the tube first to bend the tube in a vertical plane. Horizontal dies are wedged inwardly spreading the first die set and bending the tube in a horizontal plane. As a result, a compound configuration may be placed on the tube making it suitable for use in a vehicle manifold.

A Fuzzy Self-Learning Control Method with Application to Hydroforming Processes

Abstract: In this paper, a tracking control of hydroforming pressure which is used for precision forming of sheet metals, is considered. In this process, forming pressure of the process needs to be strictly controlled to ensure high quality of the forming products. However, conventional control method alone makes it difficult to achieve satisfactory control performance due to complexities and uncertainties of the process. To overcome this problem, a fuzzy self-learning control scheme is proposed. In the proposed scheme, a series of experiments were performed to show the effectiveness of the proposed control scheme and to investigate influence of the design parameters of the proposed algorithm. The experimental results show that the proposed fuzzy self-learning controller can guarantee good tracking performance and thus, high quality of products even when knowledge of the process is vague, imprecise and fragmentary.

Protected seal for blow down platen

Abstract: A blow down hydroforming apparatus for sheet material incorporates an hydraulically inflatable seal disposed between a platen and a table in circumscribing relationship with a cavity formed in the platen to maintain the pressure of gas in the cavity during forming of the sheet material.

Process and apparatus for hydroforming a vehicle manifold

Abstract: A hydroforming process and apparatus 10, for shaping tubular members of a vehicle exhaust or intake manifold to the desired configuration for use in the manifold. The tubular member 100 is loaded into the apparatus and filled with a suitable liquid 14. The liquid within the member is pressurised in order to maintain a predetermined internal fluid pressure which prevents collapse and crimping of the tube during forming by its ends being engaged between hydraulically actuated opposing plugs 24. The apparatus includes two sets of dies to form a compound bend in the pressurised member. Upper and lower dies 32, 26 close on the member first to bend the tube in a vertical plane. Horizontal dies (not shown in Fig. 2) am wedged inwardly spreading the first die set and further bending the member in a horizontal plane. As a result, a compound curvature of the member is provided for use in the vehicle manifold.