| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for hardening the inner peripheral surface of a cylindrical member with which the inner peripheral surface of the cylindrical member can be hardened while restraining the deformation without needing large electric power. <P>SOLUTION: The hardening method for inner peripheral surface of the cylindrical member is performed, with which the cylindrical member 20 is induction-heated by time t1 with an induction heating coil 40 under fixing state without rotating and vertically shifting, and a portion faced to the approached portion 40a in grooves 24 is heated to hardening temperature. In such a way, while rapidly cooling by injecting cooling liquid to the induction-heated portion into the hardening temperature from a cooling jacket 47, the cylindrical member 20 is started to rotate and descend. In this way, while ascending the induction-heating coil 40 along the grooves 24, the portion faced to the approached portion 40a is induction-heated into the hardening temperature and also, the portion heated into the hardening temperature is rapidly cooled with the cooling liquid jetted from the cooling jacket 47. After completing the time t1, while rotating and descending the cylindrical member 20 by time t2, being induction-heated with the induction-heating coil 40 and cooled from the cooling jacket 47. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
