APPARATUS AND METHOD FOR HARDENING BEARING SURFACES OF A CRANKSHAFT

摘要

An apparatus and method for hardening the concentric main bearing surfaces and orbital pin bearing surfaces of a crankshaft for an internal combustion engine rotatable about the common center axis of the main bearing surfaces. The apparatus comprising an inductor for encircling each one of the surfaces to be hardened over at least a portion of the surface and riding on the surface where the inductors are connected to a high frequency power source with a power controller to cause the power source to direct a given power to the inductor at given rotational heating positions of the crankshaft. A quench chamber is associated with the inductor and has outlet orifices directed toward the surface encircled by the inductor. A supply of quenching liquid with a flow controller directs a given quantity of quench liquid against the surface after the surface has been inductively heated by the inductor. A master controller creates output signals to control the power controller for each of the surfaces encircled by an inductor and at rotational positions in arcuate power control increments of less than 30 degrees, but preferably about 10 degrees. The master controller may also provide incremental pulsed quench control at rotational positions in arcuate quench control increments of less than about 360 degrees. The apparatus and method includes a first multi-surface hardening station with encircling inductors for all of the main bearing surfaces, a second multi-surface hardening station with encircling inductors for pins 2 and 3 and a third multi-surface hardening station with encircling inductors for pins 1 and 4. Total indicator run out (TIR) is measured after the first station to adjust the heating process in the third station to produce a straight crankshaft.