| 摘要 |
PURPOSE:To harden steel pipes without producing flaws by the impact with the surfaces of the steel pipes or without causing hardening irregularity over the entire part of the steel pipes in the stage of hardening the steel pipes by dipping the steel pipes into cooling water while gripping the same with the cradle at the leading end of a rotating arm. CONSTITUTION:A heated steel pipe 19 rolls on the skid 16 over a cooling tank 11 and is once stopped by a stopper 21 at one end face of an arm 15. An oil hydraulic cylinder 13 is operated to rotate the arm 15 clockwise around a revolving shaft 12, thereby lowering the end part of the stopper surface and stopping the steel pipe 19 in abutment on the arc-shaped piece 18a provided to the cradle 18 in the end part 5 on the opposite side of the arm 15. Next, the arm 15 is rotated counterclockwise to dip the cradle 18 together with the pipe 19 into cooling liquid 17, whereby the pipe 19 is hardened. Next, an oil hydraulic cylinder 23 is operated to rotate an arm 25 around a shaft 22 and to drop the hardened pipe 19 into a carrying-out skid 28 from the cradle 18 by means of the leading end part thereof. After the pipe is thoroughly cooled by this, it is removed from the cooling tank 11 with chain dogs or the like. |
