PLUG HARDENING DEVICE AND METHOD

摘要

PROBLEM TO BE SOLVED: To provide a plug hardening device and method capable of reducing exchange time of a core grid at a hardening position.SOLUTION: A plug hardening device 100 for performing hardening processing of an annular workpiece W with a state that an inner diameter of the workpiece W is restrained, comprises: plural hardening units 110 into which the workpiece W is accommodated respectively; a hardening part 150 for performing hardening processing of the workpiece W accommodated in the respective hardening units 110; and hardening unit movement means 140 for moving the respective hardening units 110 into the hardening part 150 independently each other. The respective hardening units 110 have a core grid 116 inserted into the inside of the workpiece W, respectively.