| 摘要 |
PURPOSE:To eliminate the generation of burrs when the said part is processed and the removing process of burrs, in a captioned shaft having port grooves with chamfer parts on its periphery, by forming a level difference between chamfer parts and the periphery. CONSTITUTION:In a rotary type valve mechanism for a power steering system, a rotary valve shaft 22 rotated by a steering wheel is provided with port grooves 22a formed by grinding process or the like on its periphery and chamfer parts 22b shaped on their edges. At this point, a concave part A with a V-shaped section is formed at both edge parts of the bottom of each port groove 22a with the chamfer part 22b as one side. The other side of this concave part A and the periphery of the shaft 22 form a sharp-edge-shaped level difference 22c, which is desirably processed by pressing and prevents the generation of metal roughs at the time of processing. |
