PURPOSE: To enable quenching of plural parts to be quenched in a long-sized work in a short time by using plural saddle shaped semi-opening type coils, cooling liquid injecting jackets and pseudo induction loads, and executing reciprocatively shifting quenching to the work.
CONSTITUTION: The parts H1, H2, H3 to be quenched having plural different lengths in the long columnar work 100 are quenched with the high frequency reciprocatively shifting quenching method. Then, plural works 100 are quenched in order. Electric currents are started to conduct at the same time to plural saddle shaped semi-opening type heating coils 10, 20, 30, separately laid on each part H1, H2, H3 to be quenched, and the cooling liquid is injected from each jacket 16, 26, 36 and shifted. After completing the heating, the heating coils 10, 20, 30 are lifted in order. The pseudo heating coils 15, 20 are inserted in electric feeding loops 13, 23 except the longest quenching part. Successively, the second work is quenched by shifting the coils and the jackets to the reverse direction. In this way, the reciprocatively shifting quenching is executed to plural works 100. By this method, fitting and detaching of the long work to the quenching position can be easily executed.
KASHIWABARA MASAYUKI
MUTO YASUO
