JPS5570421A - Roll forming method for cylindrical pipe - Google Patents

Abstract

PURPOSE: To manufacture the cylindrical pipe with good sectional shape, by approximately equalizing the forming angle of the cylindrical formed product and the angle of inclination of the conical face of the forming roll, and by carrying out the forming work approximately linearly changing the forming angle from small at the first stand to large at the latter forming stand, correspondingly to the position of the forming stand in the forward direction of the forming work.

CONSTITUTION: The apparatus for manufacturing the cylindrical pipe from the metallic sheet 1 according to the roll forming method, is constituted of the feed roll 11, forming rolls 12W16, fin rolls 17W19, etc. The sectional shape of the formed product obtained from metallic sheet 1 is assumed to be approximately circular arc, and the angle made by the tangent to the circular arc at the side edge of the formed product against the horizontal direction is called as the forming angle; this forming angle is made approximately equal to the angle of inclination of the conical face of the forming rolls 12W16; and also, the forming angle is enlarged approximately linearly toward the latter forming stand correspondingly to the position of the forming stand in the forward direction of the forming work; and then, the forming work is carried out. The section of the cylindrical pipe formed by this method is prevented from being deformed into polygonal shape.

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