초록 ▼

Method of deep-rolling of crankshaft pins by applying different rolling forces over a rotational angle (phi) of 360°, such as to produce in each angular position a constant enlargement of the angle (alpha) subtended by the mirror faces i.e. the faces connected with the respective transition radii to

Method of deep-rolling of crankshaft pins by applying different rolling forces over a rotational angle (phi) of 360°, such as to produce in each angular position a constant enlargement of the angle (alpha) subtended by the mirror faces i.e. the faces connected with the respective transition radii to provide, at least, in the angular region most subject to damage the desired fatigue strength increase.

대표청구항 ▼

1. The method of deep rolling the fillets of a workpiece having bearing pins parallel to the axis of rotation, said bearing pins being bounded at at least one end by a lateral surface, each of said fillets forming a transition radius between the said lateral surface and the surface of a related bear

1. The method of deep rolling the fillets of a workpiece having bearing pins parallel to the axis of rotation, said bearing pins being bounded at at least one end by a lateral surface, each of said fillets forming a transition radius between the said lateral surface and the surface of a related bearing pin, comprising the steps of rotating said workpiece about its axis while simultaneously continuously applying to the said fillets a rolling force of varying magnitude, the magnitude of said rolling force being maintained at a value to cause said lateral surfaces of said bearing pins to assume a constant angle of enlargement relative to the axis of said pins throughout an entire rotation of said workpiece, said rolling force being at least of the magnitude necessary to produce a desired fatigue strength increase in selected arcuate areas of said workpiece. 2. The method in accordance with claim 1 wherein the minimum value of the rolling force applied is at all times sufficient to achieve a smooth rolling result. 3. The method in accordance with claim 1 wherein said rolling force pulsates at a frequency of from about 30 to 300 Hz and at an amplituted of from about 5 to 50% of the instantaneous average value of the rolling force. 4. The method of claim 1 and including the step of providing a radial cam having a profile coordinated with the rolling force necessary to achieve said constant angle of enlargement, rotating said cam in synchronized relation to said workpiece, and varying the rolling force applied to said workpiece as a function of the rotated position of said cam. 5. The method of claim 4 and including the step of forming said radial cam by first rolling a said workpiece with a constant high rolling force to thereby induce a permanent angle of enlargement of said lateral surfaces relative to the axis of said pins, and thereafter forming the profile of said cam as a function of the degree of enlargement of said lateral surfaces. 6. The method of deep rolling the fillets of a workpiece, to be formed into a crankshaft having bearing pins parallel to and offset from the axis of said crankshaft, said bearing pins being bounded at opposite ends by mirror surfaces substantially perpendicular to the axis of the crankshaft comprising the steps of rotating said crankshaft about its axis while simultaneously continuously applying to the said fillets a rolling force of varying magnitude, the magnitude of said rolling force being continuously maintained at a value to cause said mirror surfaces to opposite sides of said bearing pins to assume a constant angle of enlargement relative to the axis of said bearing pins throughout an entire rotation of said workpiece, said rolling force being at least of the magnitude necessary to produce a desired fatigue strength increase in selected arcuate areas of said workpiece.