METHOD OF HELICAL SPRINGS HARDENING Russian patent published in 2016 - IPC B21F35/00 C21D9/02 F16F1/06 

FIELD: machine building.

SUBSTANCE: invention relates to machine building and can be used during helical compression springs hardening. Method comprises spring winding with pitch exceeding pitch of finished spring, thermal treatment, wheel blasting, penetrant inspection and thermally treated spring ends polishing. At final stage, spring outer and inner surfaces cold-hardening is carried oud and spring surface cold-hardening along turns to each other contact line. Spring outer and inner surfaces cold-hardening is performed by stamping using hardening device when spring is in female die opening by means of spring turns expansion to female die opening surface by male die entering into it. Gap between female die and male die surface opening is selected less than spring turn diameter for 0.2…2 mm. Spring surface cold-hardening along spring turns contact line between each other is performed by spring compression with force of 5…300F₃, where F₃ is spring force at maximum strain_.

EFFECT: higher efficiency of hardening and spring elastic properties stability.

3 cl, 3 dwg