METHOD FOR MANUFACTURING A DAMPER IN YOUR MOLD PLATE PROGRESSIVE

摘要

The present invention relates to a method to manufacture a damper inner plate in a progressive mold and, more specifically, relates to a method to efficiently manufacture a damper inner plate without any defects. The present invention, when manufacturing a damper inner plate by drawing by stage in a progressive mold, makes a conveying bridge processing a first pilot pin piercing and a second circular lancing piercing to a third hourglass lancing piercing to manufacture by drawing by stage after the above work. In the present invention, when a metal plate material is entered in the progressive mold, the conveyance distance is set through the first pilot pin piercing process; an edge defect on the damper inner plate is removed through the second circular lancing piercing process; a pulling state of the materials is made uniform through the third hourglass lancing piercing process to minimize the changes in thickness; and since drawing is conducted by stage, the changes in thickness and defects such as a rupture can be removed, and the damper inner plate efficiently manufactured.