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Apparatus and method for hydroforming a dual wall conduit having a controlled size gap between the walls, a frame having an upper crown and a lower bed defining a hydroforming space therebetween, the bed having a slideway extending from the space to a load-unload-preform position out of the space. A

Apparatus and method for hydroforming a dual wall conduit having a controlled size gap between the walls, a frame having an upper crown and a lower bed defining a hydroforming space therebetween, the bed having a slideway extending from the space to a load-unload-preform position out of the space. A mold assembly on the slideway has a lower platen and an upper platen defining at least two hydroforming cavities, one cavity being an elongated preform and semi-finish cavity, and the other cavity being an elongated finish cavity. Mold shifting means is positioned for shifting the mold assembly on the slideway from the position in the space between the crown and bed, to and from the forward load-unload-preform position. Mold closing and preforming hydraulic cylinders are operably connected to the upper mold platen for closing the upper platen onto the lower platen and creating mechanical preforming on dual wall tubular stock in the preform and semi-finish form cavity. The upper crown has a peripherally retained bladder over the mold assembly for applying a closure clamping force on the mold assembly by the bladder. A first pair of double acting, tube sealing, hydroforming elements are at the ends of the preform, semi-finish cavity, and a second pair of tube sealing hydroforming elements are at the ends of the finish cavity.

대표청구항 ▼

Apparatus for forming a dual wall conduit having a controlled size gap between the walls, from dual wall tubular stock, comprising: a frame having upper and lower parts; a fixed upper crown on said upper part, and a fixed lower bed on said lower part, spaced from said upper crown to define a hydrofo

Apparatus for forming a dual wall conduit having a controlled size gap between the walls, from dual wall tubular stock, comprising: a frame having upper and lower parts; a fixed upper crown on said upper part, and a fixed lower bed on said lower part, spaced from said upper crown to define a hydroforming space therebetween for receiving a mold assembly; said bed comprising a slideway extending from said space to a load-unload preform position out of said space; a mold assembly on said slideway comprising a lower platen and an upper platen connected to said lower platen by a hinge, and mold elements defining at least two hydroforming cavities, one cavity being an elongated preform and semi-finish cavity having ends, and the other cavity being an elongated finish cavity having ends; mold closing and preforming hydraulic cylinders operably connected to said upper mold platen at a location spaced from said hinge, for closing said upper platen onto said lower platen and creating mechanical force between said mold elements for causing selected preform finishing on dual wall tubular stock in said preform and semi-finish form cavity; mold shifting means connected to said mold assembly for shifting said mold assembly on said slideway from said position in said space between said crown and bed, to and from said forward load-unload-preform position; said space having a height slightly greater than said mold assembly; said upper crown having a peripherally retained bladder device positioned over said mold assembly, a pressurized fluid source connected to said bladder device for applying a closure holding force on said mold assembly; a first pair of tube sealing, hydroforming elements at said ends of said preform, semi-finish cavity; and a second pair of tube sealing hydroforming elements at said ends of said finish cavity.