METHOD OF L-SHAPED FIXING ELEMENT MANUFACTURE AND TANDEM DIE FOR METHOD IMPLEMENTATION Russian patent published in 2009 - IPC B21D22/02 

FIELD: metallurgy.

SUBSTANCE: invention relates to pressurised metal treatment, particularly, to die making industry. A hole is made in the first die impression during the first slide moving along the press. The hole is made at the required distance from the front end of the work piece by means of a punch. Simultaneously, a neck-down core is formed in the central of the work piece within the section from its front end to an assumed radius of bending by means of the second punch sections. The neck-down core height corresponds to the height of stiffening ribs being formed. After that, the work piece height is reduced to zero from the front end to the direction of the assumed bending radius. Then strip is moved ahead up to the stop and cut. Then, the work piece is bent by die till L-shaped profile is achieved in the second die impression during the second press slide moving. At the end of the movement, stiffening ribs are formed by the profiled die surface along the whole work piece length. The whole process is repeated for the next work piece. The tandem die includes top and bottom plates, guide with holder, punch and punching die, cut-off device, bending punch and die and work piece stop.

EFFECT: improved efficiency and reliability of fixing elements.

4 cl, 5 dwg