| 摘要 |
PURPOSE:To prevent non-quenching face from roughening caused by spark by closely bringing each non-quenching face of plural works having polygonal section and long columnar shape into contact with each jointing block and executing shifting quench by a surrounding type high frequency induction quenching coil. CONSTITUTION:The electric conductive jointing block 12 having almost rectangular shape section is inserted between each non-quenching faces 111a, 111b of the works 11a, 11b having almost rectangular shape section and long columnar shape to closely bring into contact with and fix to the non-quenching faces 111a, 111b and the high frequency induction quenching coil is arranged so as to surround the works 11a, 11b. At the time of conducting current to this quenching coil 10 toward the arrow mark A direction, the current flows toward the arrow mark B direction through the works 11a, 11b and the block 12 and the spark between the non-quenching faces 11a, 11b and the block 12 is not generated. Under this condition, the works 11a, 11b are shifted to the longitudinal direction and the other three faces in the works 11a, 11b are heated and next, by cooling liquid, they are cooled to execute the surface quenching.
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