INDUCTION PLANT FOR SURFACE HARDENING OF GEAR-WHEEL MEMBERS, METHOD FOR HIGH-FREQUENCY CHECK OF GEAR-WHEEL MEMBER TEMPERATURE, INDUCTION HARDENING PLANT, METHOD FOR HIGH- FREQUENCY CONTROL OF POWER SUPPLY TO INDUCTION HARDENING PLANT Russian patent published in 1998 - IPC

FIELD: surface hardening of machine members, such as gear wheels. SUBSTANCE: induction hardening plant has phase angle recording circuit that shapes pulse each time measured phase angle of ac current signal is recorded. Pulse shaped by phase detector is applied to circuit input coupled with starting relay; to ensure operation of this circuit, mentioned pulse must arrive at it and starting relay must operate simultaneously to shape output pulse signal of definite width. This pulse signal actuates respective devices functioning to turn on or off power supply and to supply respective working signal to high-frequency oscillator feeding induction heating coil. EFFECT: provision for fully controlled induction heating due to high-frequency regulation of high-frequency oscillator output signal. 14 cl, 4 dwg