METHOD OF MAKING SPRINGS WITH HIGH STRENGTH Russian patent published in 2019 - IPC B21F35/00 

FIELD: manufacturing technology.

SUBSTANCE: invention relates to production of steel helical compression springs with high structural strength, which operate in aggressive hydrogen sulfide containing medium. Proposed method comprises spring winding from bar, its heat treatment and cold-hardening. Winding of spring is performed on mandrel made on working surface with spiral groove, direction and pitch of which correspond to direction and pitch of coiled spring, and with cross-section in form of circle. Cold hardening is performed by inner and outer spring surface rolling by hardening device containing two deforming rollers arranged at 180° relative to each other and at angle of 90° between rotational axis of roller and axis of winding wound on rod. Deforming rollers are made with groove on their cylindrical surface, which corresponds to dimensions of mandrel groove. Cold hardening is performed after winding of the spring and after its heat treatment.

EFFECT: increased resistance of spring against fatigue, corrosion under load and wear.

1 cl, 3 dwg