METHOD FOR INCREASING WALL THICKNESS OF WORK BOSS PART, AND WALL THICKNESS INCREASING DEVICE USED THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a method and a device for increasing the wall thickness of a work boss part in which the boss part can be formed by increasing a circumferential wall of a vertical cylindrical part of the work and the manufacturing cost can be reduced by one swaging operation without any more swaging operations.;SOLUTION: A plate part 10 of the work 1 is held by a work placement face 32 of a work supporting part 3 and a die 5 by performing one swaging operation to press the vertical cylindrical part 12 by a punch 6 in the swaging direction where L is the buckling preventive distance of preventing any buckling phenomenon of the vertical cylindrical part 12 of the work 1. In a state in which a wall thickness increasing space 65 is formed between a mandrel 4 and the vertical cylindrical part 12, the mandrel 4 is retracted in the swaging direction of a punch 6 while the material of the vertical cylindrical part 12 is allowed to flow into the space 65. The boss part is formed by increasing the thickness of the vertical cylindrical part 12 while maintaining the length of a swageable part of the vertical cylindrical part 12 to be within L, and the vertical cylindrical part 12 is swaged to shorten the length in the axial direction of the vertical cylindrical part 12.;COPYRIGHT: (C)2003,JPO