Patent ID: 7207201
Filing Date: 2007-04-24
Classification: B21D,Y10T

Abstract:
1. An U/Z-shaped steel bar manufacturing process, which comprises the steps of: a) feeding a steel sheet metal from a roll of steel sheet metal located on a spindle of a material rack to a flattening machine; b) flattening the steel sheet metal to form a flattened steel sheet metal utilizing a flattening machine and feeding the flattened steel sheet metal into a punch press; c) punching punch holes in the flattened steel sheet metal and cutting the flattened steel sheet metal to a predetermined length forming a punched steel sheet metal having a plurality of holes having a predetermined pattern utilizing a plurality of punch dies of the punch press; d) rolling the punched steel sheet metal into a steel bar having a cross section having a predetermined shape utilizing ramming rolls of a roll forming unit, the predetermined shape is selected from a group consisting of a U shape and a Z shape; and e) straightening the steel bar utilizing a straightening machine to form the U/Z-shaped steel bar, wherein in the punching step c), the predetermined pattern is formed by selectively moving a selected punch die of a plurality of a plurality of punch dies between punching and non-punching positions, when the selected punch die is located in the punching position, a plurality of heads of the selected punch die are located on a bottom surface of the selected punch die positioning a plurality of punch rods connected thereto in a punching rod position, and, when the selected punch die is located in the non-punching position, the plurality of heads of the selected punch die are located entirely in recessed portions located in the bottom surface of the selected punch die positioning the plurality of punch rods connected thereto in a non-punching rod position.