| 摘要 |
PURPOSE:To prevent generation of uneven quenching on receiving mouth internal surface due to uneven cooling by a method wherein uniform heating is applied to the receiving mouth internal surface of constant-speed universal joint outer ring of a car, then cooling water is brought into uniform contact with the entire area of the receiving mouth internal surface. CONSTITUTION:On a turn-table having a throughhole 10 at its center, is mounted the receiving mouth of constant-speed universal joint of a car so that the mouth 3 faces downward. A high-frequency heating coil 11 supported by rod 12 having water supply pipe 13 is inserted through the throughhole 10 into the internal surface of the receiving mouth 3. The turn-table 9 is rotated and current is passed through the coil 11, so that the internal surface of the mouth 3 is uniformly heated by induction. Then, cooling water is supplied from the pipe 13 and is jetted from nozzles 14 at the end of the pipe 13. Cooling water is controlled in direction by umbrella type rectification plate 15 so as to uniformly cool recessed groove on the mouth 3 internal surface and rib section 8 where wall thickness is different. This effectively removes uneven cooling and prevents quenched layer B from becoming uneven thickness. |
