| 摘要 |
PURPOSE:To form a uniform hardened part over the entire surface layer of a tooth profile by injecting cooling fluid having controllable cooling power to the top part and belly part of the tooth profile heated to prescribed temp. thereby cooling the same quickly. CONSTITUTION:Induction coils C are saddled on a tooth profile G1 from above in such a way that the inner sides in the longitudianl direction of the conductors 1 of said coils maintain a prescribed spacing over the entire part of the opposite tooth belly parts Gs of the tooth profile G1. Cooling fluid is flowed from a supply source P1 to a passage 1b, and a high frequency electric power source is turned on to heat the surface layers of the tooth belly parts Gs and tooth top part Gr of the tooth profile G1 by the magnetic lines of force from the conductors 1, thereby attaining hardening temp. Thence, the high frequency electric power source is turned off; at the same time, a fluid supply source P2 is driven and the cooling fluid of the flow rates controlled with valves 4a, 4b is supplied to a passage 1a and an injection pipe 5 through pipes 3a, 3b, so that the fluid is injected through injection holes 12 to the direction of the upper part Gsv and lower part GSD of the parts Gs. Also, the fluid is injected directly to the tooth top part Gr through injection holes 51. Thereby, the tooth part G1 is cooled uniformly. |
