| 摘要 |
<p>PROBLEM TO BE SOLVED: To cleanly remove oil on an inner surface of a product, and to continuously use a scraping rubber for a long time by providing a hooked bolt on a tip of a mandrel, and arranging the grooved scraping rubber having a spring through the spring linked with the bolt. SOLUTION: A reciprocating ring die 1 rolls the outside diameter of a base tube 2. A mandrel 5 inserted in the inside diameter side of the base tube 2 determines the wall thickness of a product 8. An inner surface lubricating oil 4 and an outer surface lubricating oil 6 are supplied to the base tube 2 to cool the machining heat. A hooked bolt 12 is provided on a tip of the mandrel 5, a spring 3 is linked with the hooked bolt 12, and a scraping rubber 14 is arranged on a tip of the spring 13. A groove is provided in the scraping rubber 14. The scraping rubber 14 is pressed against an inner surface of the product 8 with a large force by the spring effect of the groove, and the scraping rubber 14 follows the motion of the product 8 by the spring 13 to cleanly remove the inner surface lubricating oil 4.</p> |
