Curved tubular product, in particular a vehicle air spring, manufacture, involves pressure forming of tube with hot fluid against vulcanization tool wall

摘要

A tubular section (10) of suitable length is filled with a heated fluid. The fluid is pressurized and presses the tube against the wall of a tool (30) where it is vulcanized in its final shape. A tube length (10) is placed in a vulcanizing tool (30) and sealed at both ends by clamping with end plugs (41, 42) against the inside of the tool. Clamping is effected by dividing the tool and moving the separate parts along the tool axis towards the end plugs. The tube is slightly pressurized via the end plugs and then the tool is closed. Pressure is then increased to the full vulcanization pressure by introducing steam. An independent claim is included for the vulcanization equipment including a vulcanizing tool (30) divided perpendicular to the length of a cut tube (10) length to be vulcanized. Two end pugs (41, 42) inserted into the tool ends hold the tube section in the tool and pressurizing fluid is introduced through one or both end plugs.