| 摘要 |
A bolt insertion hole (7a) into which a securing bolt (16) to be fastened to a knuckle is formed in each of a plurality of portions in the circumferential direction of a vehicle body mounting flange (7), an outer member (2) is previously formed by hot forging, and the side surface (10) on the outer side of the vehicle mounting flange (7) and the bolt insertion hole (7a) are formed by cold forging, thereby making it possible to ensure desired finishing accuracy and abolish machining of the side surface (10) on the outer side of the vehicle mounting flange (7) and a drilling step. Consequently, it is possible to provide a wheel bearing device which achieves a reduction in cost by improving the yield of materials and reducing the number of processing steps. |
