| 摘要 |
A method and apparatus for inductively heating in an inductor and quench hardening the finished ground cam lobes of steel camshafts to a uniform shallow pattern depth with minimal lobe surface deformation. The inductor is shaped to correspond to the contour of and encircle the individual cam lobes with a minimal uniform induction coupling gap therebetween of less than 0.1 inch, and it is energized with high intensity power at a high frequency greater than 200 KHz, with sufficient power to create a power density of at least 25 KW/inch2 at the surface of the cam lobe being heated in the inductor, for only a short heat time less than 1.0 second so as to effect the rapid inductive heating of the cam lobe surface to a uniform elevated temperature and uniform shallow depth therearound without causing unacceptable reheating and resultant drawing back or tempering of the previously hardened next adjacent cam lobe. The inductor is comprised of two complementary elongated copper segments which are normally interconnected at one end to form a conductor loop and conjointly provide a ring-shaped inductor element of the aforementioned contour for receiving the individual cam lobes in inductive heating position therein. The inductor segments are movable apart laterally outward from the camshaft a sufficient distance to permit both axial and rotative index movement of the camshaft relative to the inductor to position the other cam lobes of the camshaft individually in proper axial and rotative oriented position for encirclement and inductive heating by the inductor.
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