METHOD FOR DEEP-ROLLING TRANSITIONS BETWEEN THE BEARING JOURNALS AND THE FLANGES OF CRANKSHAFTS

摘要

The invention pertains to a method for deep-rolling radiior fillets (2) at the transition between the bearingjournals (3) and the adjacent flange (4) of a bearingpoint of a crankshaft (1) with the aid of deep-rollingcylinders. The deep-rolling cylinders are pressed intothe radius or the fillet (2) of the transition with adeep-rolling force until a predetermined roll-down depth(10) is reached while the crankshaft (1) is turned. Thetransition is initially deep-rolled with a first deep-rollingcylinder, the radius (6) of which has anosculating ratio between 1 and 0.85 referred to theradius of the transition or the fillet (2), namely with afirst deep-rolling force that produces a maximum internalcompressive stress (7) in the transition at a depthbetween 1 and 2 mm below the deep-rolled surface (8). Thesame transition is subsequently rerolled with a seconddeep-rolling cylinder that has a smaller radius (14) thanthe first deep-rolling cylinder (5), the magnitude ofwhich is chosen such that the second deep-rollingcylinder causes a further plastic deformation (11) on thedeep-rolled surface (8) of the transition in addition tothe plastic deformation achieved with the firstdeep-rolling cylinder.