• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.10a
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• pp.204-207
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• 2001

The bending process for the circular curved tube and rectangular curved tube with fins can be developed by the hot metal extrusion machine with the multiple punches moving in the different velocity. The bending phenomenon can be controlled by the two variables. The one of them is the difference of velocity at the die exit section by the different velocity of billets through the multi-hole container. The other is the one by the different hole diameter. The results of the experiment show that the circular curved tube with fins and rectangular curved tube with pins can be formed by the extrusion process and that the curveture of the product can be controlled by the velocity of punch and diameter of container hole and that the defects such as the distortion of section and the thickness change of the wall of tube the folding and wrinkling of thin tube and fins did not happen after the bending processing by the extrusion bending machine.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.10a
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• pp.212-215
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• 2001

The bending process for the rectangular curved tube can be developed by the hot metal extrusion machine with the multiple punches moving in the different velocity. The bending phenomenon can be controlled by the two variables, the one of them is the difference of velocity at the die exit section by the different velocity of billets through the multi-hole container. The other is the difference by the different hole diameter. The results of the experiment show that the rectangular curved tube can be formed by the extrusion process and that the curvature of the curved product can be controlled by the velocity of punch and the diameter of container hole and that the defects such as the distortion of section and the thickness change of the wall of tube and the folding and wrinkling of thin tube did not happen after the bending processing by the extrusion bending machine.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.05a
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• pp.102-105
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• 2001

The bending process for the curved tube can be developed by the hot metal extrusion machine with the multiple punches moving in the different velocity. The bending phenomenon has been studied to be occurred by the different of velocity at the die extrusion. The difference of velocity at the die exit section can be obtained by the different velocity of billets through the multi-hole container and by the welding of billets inside the porthole die chamber. The multiple billets are moving differently by the multiple extrusion punches controlled by PLC with the servo mechanism units. The results of the experiments show that the curved tube can be bended by the extrusion process and that the defects such as the distortion of section and the thickness change of thick tube, tile folding and wrinkling of thin tube can not be shown after the bending processing by the extrusion bending machine.