| 摘要 |
PURPOSE:To improve the hardening efficiency of a steel pipe by providing a pair of rollers on plural rotary stands which are provided on a cooling vessel, and furnishing a means for blowing a cooling medium into the steel pipe which is immersed in the cooling vessel by the rotation of the stands. CONSTITUTION:A carried-in steel pipe 1 to be hardened is transferred onto a supporting roller 12 provided to plural rotary stands 4, and a working shaft 15 is turned to retain the steel pipe 1 between a supporting roller 14 at the leading end of the shaft 15 and said supporting roller 12. The stand 4 is rotated to immerse the steel pipe 1 into a cooling vessel 2, and cooling water is blown into the steel pipe 1 by advancing a nozzle 18. The outer surface of the steel pipe 1 is also cooled by the cooling liquid in the vessel 2. Meanwhile, a succeeding steel pipe 1 is retained between supporting rollers 12 and 14. Then the spouting of the cooling water from the nozzle 18 is stopped, and the stand 4 is rotated. The treated steel pipe 1 is dropped from between the supporting rollers 12 and 14 onto a conveyor, etc., and transported to a specified position. |
