| 摘要 |
<p>PURPOSE:To rationally relieve the residual stress in each fillet part of a crankshaft and to improve the fatigue strength by properly combining the distribution, temps. and times of heating and cooling of each part of the crankshaft. CONSTITUTION:An outside heater 4 and an inside heater 5 are fixed on the outside and inside of each journal part 3 of a welded crankshaft 1 including a weld zone 2. The outside heater 4 is heated to a stress relief annealing temp. dependent on the material, e.g., to 650 deg.C and is kept at the temp. The inside heater 5 is kept at a temp. below the temp. of the outside heater 4 by <=about 100 deg.C, e.g., at 600 deg.C. While the journal part 3 is held under heating, each fillet part 6 is forced to be cooled by feeding a cooling medium such as air or water as shown by arrows 8 or by using a chilling block so that the temp. of the fillet part 6 does not exceed 500 deg.C at a temp. measuring point 7.</p> |
