METHOD OF UNIFORM INDUCTION HEATING OF AN ELONGATED WORKPIECE

摘要

METHOD OF UNIFORM INDUCTION HEATING OF AN ELONGATED WORKPIECE ( ) A method for uniformly heating an elongated workpiece having a first portion with uniform cross-section over a major portion of the workpiece length and a second portion having a larger cross-section than the first portion. A multi-turn inductor is operatively mounted on a carriage or the like and is coaxially disposed about an elongated workpath. The carriage is selectively movable axially of the workpath from a first or home position. As the workpiece first portion is fed along the workpath at some preselected rate of travel into and through the inductor, it is heated to a desired temperature over the length thereof. The inductor carriage is energized as the enlarged workpiece second portion enters the inductor so that the inductor will travel along the workpath with the workpiece. Such travel increases the heating time for the second portion so that it too is heated to the desired temperature. After a predetermined time interval, the carriage movement is reversed back toward the first or home position. The method is adapted to use with workpieces having plural enlarged areas spaced therealong and is adaptable to simultaneous heating of a plurality of workpieces with plural inductors.