Abstract:
PROBLEM TO BE SOLVED: To provide a roll suspending tool capable of performing crane suspending in a safe and easy way without tilting a roll unit in which a weight distribution is ununiform when an exchange of the roll unit is easily performed in a roll stand.SOLUTION: A suspension shaft 40 with which a hook 70 of a crane is engaged is swingably connected to an upper side of a suspending frame 20 with a slant lever 50. The slant lever 50 is pivoted at a position shifting in a horizontal direction relative to a gravity line of the supporting frame 20, and elastically held in an inclined status with a spring mechanism 60. In a state that the suspending tool is crane-suspended alone, a center of gravity of the suspending tool is positioned just under a suspending position. In a state that the suspending tool is crane-suspended while the suspending frame 20 cramps the roll unit downward, the spring mechanism 60 is elastically deformed, and the slant lever 50 stands up. The center of gravity of the suspending tool is apart from a position just under the suspending position toward the horizontal direction, and a combined center of gravity of the suspending tool and the roll unit is moved to near a position just under the suspending position.
Abstract:
PROBLEM TO BE SOLVED: To perform the roll-forming of a circular tube into a square tube without giving any excessive burden on scheduled portions for corner parts and shoulder parts of a stock tube, and to manufacture a square tube having high accuracy of the dimension and the shape and excellent internal quality at low cost with common use of the roll. SOLUTION: The curvature of a forming roll surface in the direction of the axis of rotation is constituted so that a stock tube portion (a shoulder part scheduled portion) adjacent to a corner part scheduled portion of a square tube is straightened prior to the other stock (the other ridge part scheduled portion). For example, stands of four-roll configuration are arranged for the most upstream and most downstream side forming roll stands, and upper and lower and right and left stands of two-roll configuration are arranged therebetween. By employing the forming roll of the configuration in which the curvature of restraining the stock tube portion forming a shoulder part adjacent to the corner part of the square tube is smaller than the curvature of restraining the stock tube portion forming a center of ridge parts of the section of the square tube, the roll common use effect and the equipment cost can be optimally balanced, and the square tube having excellent quality can be manufactured at low cost together with common use of the roll. COPYRIGHT: (C)2006,JPO&NCIPI
Abstract:
PROBLEM TO BE SOLVED: To provide a pipe cutting method elongating the serviceable life of a cutter, reducing the running cost, enhancing the cutting speed to such an extent as is applicable to a production line for a small-diameter pipe of high production speed, and producing an extremely favorable cutting surface quality in a cutting machine adopting a milling cutter, or a carbide tip saw in particular, as the cutter. SOLUTION: Ultrasonic vibration is applied in the specific direction, namely a cutting direction, of an outer circumferential edge so as to elongate the serviceable life of the cutter, enhance the cutting speed, and improve the cutting surface quality. The application of the ultrasonic vibration facilitates the discharge of the cutting chips and hardly produces a built-up edge so as to greatly improve the cutter serviceable life in cutting a stainless steel pipe, greatly improves the finishing accuracy of the cutting surface, and dispenses with post-machining such as burr removal for the cutting surface. COPYRIGHT: (C)2004,JPO