JPS57206521A - Pipe forming device - Google Patents

Abstract

PURPOSE:To obtain a pipe forming device which is capable of forming a pipe by small pressing force, and also can be automated, by consituting so that both end parts of a working plate can be formed to a downward pipe by cooperation of an arc surface die cavity of an upper die, an arc-like die carity of a lateral die, and an upward mandrel. CONSTITUTION:Lateral dies 6, 6a are junctioned with a mandree 5 by oil pressure cylinders 7, 7a, and a steel plate material P is placed on a prescribed position of the upper surface of the lateral dies 6, 6a. Subsequently, both ends of the material P are bent like an arc by lowering an upper die 11 and making its die cavities 15, 15a press- contact with die cavities 10, 10a of the lateral dies 6, 6a, and after that, as the upper die 11 rises, the material P is also sucked by electromagnets 16, 16a, and is raised. Subsequently, the lateral dies 6, 6a are shifted backward respectively. After that, by lowering the upper die 11, the material P is bent from the center part in a twice-folded state by a die cavity 14 in the center part on the lower surface of the upper die, and the mandrel 5. Subsequently, the lateral dies 6, 6a are advanced again, are made to press-contact with the mandrel 5, and the material P is deformed further inward by curves surfaces 9, 9a of the front of the lateral die, and the mandrel 5, and a pipe body is formed.