Component manufacturing method and component

{
  "publication_number": "US11408050B2",
  "country": "US",
  "kind": "B2",
  "title": "Component manufacturing method and component",
  "abstract": "A component manufacturing method includes: disposing, in a fluid, an unprocessed component having a hole that has an opening in an outer surface of the unprocessed component; creating a flow of the fluid such that air bubbles resulting from laser peening performed by irradiating an inner wall of the hole of the unprocessed component with a laser beam in the fluid flow along the hole; setting an irradiation area of the laser beam in an inner surface of the hole; and in the fluid of which the flow has been created, irradiating the irradiation area with the laser beam from the side of the outer surface through the opening.",
  "claims": [
    "1. A component manufacturing method comprising: immersing an unprocessed component in a fluid, the unprocessed component presenting a shape of a cylinder having a cavity inside and a hole that has an opening in an outer surface of the unprocessed component, the hole extending from the opening to the cavity, the unprocessed component having a first central axis, the hole having a second central axis that has an origin at a point on the first central axis and extends along a radial direction of the unprocessed component orthogonal to the first central axis; creating a flow of the fluid such that air bubbles resulting from laser peening performed by irradiating an inner wall of the hole of the unprocessed component with a laser beam in the fluid flow along the hole, the flow of the fluid being oriented from a side of the outer surface toward the cavity; setting an irradiation area of the laser beam in an inner surface of the hole by controlling a stage on which the unprocessed component is disposed, the stage being rotatable around the first central axis and the second central axis; and in the fluid of which the flow has been created, irradiating the irradiation area with the laser beam from a side of the outer surface through the opening, wherein: in setting the irradiation area of the laser beam, the irradiation area is set such that a plurality of spots of the laser beam are disposed in the inner surface along a circumferential direction of the hole, with each spot partially overlapping with and shifted by a predetermined amount from a preceding spot; and in irradiating each of the spots disposed in the inner surface along the circumferential direction of the hole with the laser beam, the stage is rotated around the second central axis so that n segment regions are irradiated with the laser beam in turns such that the spot that does not overlap with the spot having been irradiated last with the laser beam is irradiated with the laser beam.",
    "2. The component manufacturing method according to claim 1, wherein: the unprocessed component is provided with a plurality of the holes; in creating the flow of the fluid, a pump that suctions the fluid is connected to the cavity; and at least one of the holes other than the hole that is to be irradiated with the laser beam is masked.",
    "3. The component manufacturing method according to claim 1, wherein, in irradiating with the laser beam, an irradiation condition of the laser beam with which the inner surface is irradiated is varied in a circumferential direction of the hole.",
    "4. The component manufacturing method according to claim 3, wherein: in irradiating with the laser beam, the irradiation condition is varied periodically in the circumferential direction of the hole.",
    "5. The component manufacturing method according to claim 4, wherein: in irradiating with the laser beam, the irradiation condition is varied such that a compressive residual stress occurring in radial portions of the inner wall located at rotation angles of 45° and 225° in one circumferential direction of the hole from one radial direction of the hole becomes higher than a compressive residual stress occurring in the radial portions of the inner wall located at rotation angles of 135° and 315° in the one circumferential direction from the one radial direction, the one radial direction being one of radial directions of the hole that are parallel to the first central axis among radial directions of the hole having an origin at a point on the second central axis and orthogonal to the second central axis.",
    "6. The component manufacturing method according to claim 1, wherein the unprocessed component and the stage are disposed in a tank, the laser beam passes through a side wall of the tank to the irradiation area, and an optical member which guides the laser beam to the irradiation area is disposed outside of the tank."
  ],
  "description_excerpt": "The present disclosure relates to a component manufacturing method and a component.\n\nLaser peening is known as a processing technique for improving the strength of a surface of a component being processed. As described in Japanese Patent Application Publication No. 2006-322446 (JP 2006-322446 A), Japanese Patent Application Publication No. 2009-074417 (JP 2009-074417 A), Published Japanese Translation of PCT Application No. 2016-515475 (JP-A-2016-515475), and Japanese Patent Application Publication No. 2008-260064 (JP 2008-260064 A), laser peening involves focusing a laser beam on a surface of a component in water to laser-ablate the surface. Thus, plasma is generated on the surface of the component. The pressure of the generated plasma causes shockwaves, which plastically deform the surface of the component. As a result, a compressive stress occurs in the surface of the component. The resulting compressive stress is imparted to the surface of the component as a compressive residual stress.\n\nThus, laser peening enhances the strength of a component by imparting a compressive residual stress to a surface of the component. Laser peening is superior in micro-processability to shot peening described in Japanese Patent Application Publication No. 04-175561.\n\nJP 2006-322446 A describes a component (common rail) which has a rail hole provided inside and branch holes extending from the rail hole to an outer surface of the component, and in which laser peening is performed on an opening of the branch hole on the rail hole side and on an inner wall of the rail hole.",
  "cpc": [
    "C21D 10/005",
    "B23K 2101/04",
    "B23K 26/009",
    "B23K 26/122",
    "B23K 26/356",
    "C21D 1/09",
    "C21D 7/06",
    "C21D 9/08",
    "C21D 9/14",
    "C21D 9/28"
  ],
  "ipc": [
    "B23K 26/00",
    "B23K 26/356",
    "C21D 10/00",
    "C21D 9/14"
  ],
  "assignees": [
    "Toyota Motor Corp"
  ],
  "inventors": [
    "Kazumi SERIZAWA",
    "Haruka YANO"
  ],
  "filing_date": "2018-08-23",
  "publication_date": "2022-08-09",
  "grant_date": "2022-08-09",
  "priority_date": "2017-09-04",
  "application_number": "US-201816109957-A",
  "family_id": "63442447",
  "cited_by_count": 1,
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}