| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a wheel bearing device, an intermediate and a manufacturing method thereof with reduced cost achieved by reducing weight input to forging and an amount of lathe turning.SOLUTION: A wheel bearing device is provided with a bolt insertion hole 10 into which hub bolts 6a are press-fitted at equally spaced positions in a circumferential direction of a wheel attachment flange 6. Before the bolt insertion holes 10 are bored, a recess 11 is formed at each position of the bolt insertion holes 10 in a side surface 6c of the wheel attachment flange 6, in a cone-shape with an inclined plane 11a at the top and a flat bottom part 11b at the bottom. The bottom part 11b has the bolt insertion hole 11, and chamfers at both ends of the opening part formed by cutting. At least one of the two chamfers is the inclined plane 11a of the recess 11 formed by forging.</p> |
