| 摘要 |
PURPOSE:To enable re-grinding of a bearing easily by applying ball burnishing to oil hole and hole for lightweight of a crankshaft and hardening the bearing with high frequency and to enable ultimate designing by improving fatigue resistant strength of each hole. CONSTITUTION:A crankshaft 1 is provided with oil holes 6 for supplying lubricant to bearings of crank journals 2 and crank pins 3, and provided with holes 7 for lightweight. In this case, said holes 6, 7 are applied with ball burnishing. The inner circumferential faces of holes 6, 7 are made rough, and balls whose diameters are larger than those of holes are inserted into the holes, and the inner circumferential faces of holes 6, 7 are rolled and hardened to form reinforced layers. Then high frequency hardening is applied to bearing portions of crank journals 2, crank pins 3 and fillet R portions. By this, re-grinding of bearing portions can be possible and fatigue resistant strength of holes 6, 7 is improved. |
