| 摘要 |
PURPOSE:To manufacture the resistance welded tube of various kinds of diameters and thicknesses without changing a forming roll by changing the abutting direction of the forming roll of a strip steel at the resistance welding steel tube manufacturing time in accordance with the strip steel width and the necessary number of forming stages. CONSTITUTION:The pipe of small bore upto that of large bore and yet a thick strip steel are formed in circular cross section with a single form-roll in case of manufacturing a resistance welded tube by welding its both end parts by forming a strip steel 10 in a circular shape from semi-circular shape. Since the strip steel 10 is formed in circular shape by the upper and lower roll 5, 18 in case of this forming the rolling face is formed to coincide with the curve face at the upper side of the lower forming roll 5 in the end face bending of the strip steel with width and to the upper side curve face of the lower forming roll 5 in the end part bending of the strip steel with narrow width so that one part of the whole part of the cross sectional curve of these roll faces is coincided with the pre-set curve of the strip steel end part in each roll flower of the steel pipe of various outer diameters. The strip steel is formed in the aiming diameter by moving the forming roll so that the necessary curve face comes to the prescribed position according to the bore of the resistance welded steel tube, namely the width of the steel strip.
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