| 摘要 |
PURPOSE:To form compressed residual stress layer on surface of a hoop raw material or a spiral spring by giving one side surface or both surfaces itself the stroke while shifting on the plane surface or on the curved surface to longitudinal direction. CONSTITUTION:A rotary type wire brush 1 is continuously rotated to the arrow mark Z direction and the material 10 wound on a supplying roller 4 is continuously drawn with a supporting roller 2 continuously rotated to the arrow mark X direction. While this material 10 passes through gap between the rotary type wire brush 1 and the supporting roller 2, the surface is stroken with tip part of the wires 11 of the rotated wire brush 1 and plastic working is received on the surface and as a result, the surface becomes the state developing the compressed residual stress and the material is wound on a winding roller 5. By this method, the compressed residual stress developed on the surface of the material 10 has counterbalancing effect to loaded stress and the worked spiral spring reduces the harmful tension stress to fatigue and therefore, the service life thereof can be extended. |
