| 摘要 |
<p>PURPOSE:To obtain a basic form of a bleeder plug without performing a cutting work and drilling work by forming a semi-finished product by compressing a tube material inlaid with a core bar within a longitudinal hole, to an axial direction within a prescribed frame, and thereafter by drawing out the a forementioned core metal. CONSTITUTION:Intermediate dies 30a, 30b are provided with a hole 32 having a space form similar to a basic form of a bleeder plug 10, and a tube material 26 of a long cylindrical form is set to the hole 32. After a core bar 34 is inserted to a through hole 28 of the tube material 26, a cold compression work is performed towards an axial direction through an upper punch number 36 and a lower punch number 38, and the core bar 34 is drawn out from a semi-finished product 40. Thereby, the semi-finished product having a basic form of a bleeder plug is obtained without performing a cutting work and a drilling work.</p> |
