Method for manufacturing component
A manufacturing method for a shaft 1 by imparting a residual compressive stress to an inner surface 4 p of the lateral hole 4 of the workpiece 2 includes a disposing step and an irradiation step. In the disposing step, a lateral-hole mirror 14 a is disposed inside the lateral hole 4 . In the irradiation step, a laser beam L is emitted from one of an inner-side opening 4 a and an outer-side opening 4 b of the lateral hole 4 toward the lateral-hole mirror 14 a , making the laser beam L reflect on the lateral-hole mirror 14 a , and thereby applying the laser beam L to the inner surface 4 p of the lateral hole 4.
1. A method for manufacturing a component by imparting a residual compressive stress to an inner surface of a lateral hole of a hollow cylindrical body by performing laser peening, the hollow cylindrical body including an axial hole and the lateral hole, the axial hole being an internal space of the hollow cylindrical body and extending in a longitudinal direction of the hollow cylindrical body, the lateral hole being opened on an inner peripheral surface and an outer peripheral surface of the hollow cylindrical body, the manufacturing method comprising:
a disposing step of disposing a lateral-hole mirror inside the lateral hole; and
an irradiating step of emitting a laser beam from one of the two openings of the lateral hole toward the lateral-hole mirror, making the laser beam reflect on the lateral-hole mirror, and thereby applying the laser beam to the inner surface of the lateral hole, wherein
in the irradiating step, the laser beam is emitted from, of the two openings of the lateral hole, the opening located on the inner peripheral surface toward the lateral-hole mirror,
in the disposing step, an axial-hole mirror is further disposed inside the axial hole, and
in the irradiating step, the laser beam is applied to the inner surface of the lateral hole by emitting the laser beam from the opening of the axial hole in the longitudinal direction of the hollow cylindrical body toward the axial-hole mirror and making the laser beam first reflect on the axial-hole mirror and then reflect on the lateral-hole mirror.
2. The manufacturing method according to claim 1 , wherein in the irradiating step, the lateral-hole mirror is rotated around a central axis of the lateral hole, or is moved along the central axis of the lateral hole.
3. The manufacturing method according to claim 1 , wherein in the irradiating step, the laser beam is applied to at least an area of the inner surface of the lateral hole that is away from the outer peripheral surface in a radially inward direction by a distance equivalent to a minimum inner diameter of the lateral hole.
4. The manufacturing method according to claim 1 , wherein in the disposing step, the axial-hole mirror is disposed inside the axial hole by inserting a rod-like axial-hole mirror rod including the axial-hole mirror at a tip thereof from the opening of the axial hole in the longitudinal direction of the hollow cylindrical body into the axial hole.
5. The manufacturing method according to claim 1 , wherein in the disposing step, the lateral-hole mirror is disposed inside the lateral hole by inserting the rod-like lateral-hole mirror rod including the lateral-hole mirror at a tip thereof from the opening of the lateral hole located on the outer peripheral surface.
6. The manufacturing method according to claim 1 , wherein the lateral-hole mirror is a concave mirror.