| 摘要 |
PURPOSE:To improve the processing speed of a metallic tube with grooved inner surface and to make the double-grooves forming process easy by arranging the 1st and 2nd inner surface-groove processing parts on a straight line and installing continuous tube-drawing devices between both processing parts and at the rear side of the 2nd processing part. CONSTITUTION:A metallic tube 1 to be processed is sent to the 1st inner surface-groove processing part through a die 2; the tube 1 is subjected to the 1st reduction of diam. and the formation of the 1st groove 16 with the aids of a grooved plug, a processing head 5, and plural steel balls 6 for formation, and then is drawn by a caterpillar drawing device 19 through a sizing die 18. Successively, the metallic tube 1 is introduced to the 2nd inner surface-groove processing part through a tube guide 21, and is subjected to the 2nd reduction of diam. and the formation of double grooves 13 with the aids of a grooved plug 12, a processing head 22, and plural steel balls 11 for reduction, and then is drawn by the 2nd caterpillar drawing device 24 through a finish die 26, and is wound up by a winder. In this way, the resistance burdened on the tube 1 to be processed on the way of process can be dispersed. |
