# US 9,517,533 B2 · Welded portion inspection apparatus and inspection method thereof, with inspection in different zones of the molten pool > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,517,533 B2 - Document ID: US9517533B2 - Status: Granted - Kind: B2 - Application number: 14/781,129 - Filed: 2014-03-28 - Published: 2016-02-25 - Granted: 2016-12-13 - Earliest claimed: 2013-03-29 - Assignees: Toyota Jidosha Kabushiki Kaisha - Applicants: Toyota Jidosha Kabushiki Kaisha - Inventors: Keisuke Uchida; Masashi Furukawa; Hiroomi Kobayashi; Atsushi Kawakita; Shuhei Ogura; Hiroaki Kishi; Eiji Akamatsu; Yuta Iwamoto - Web page: https://patentgrep.com/patent/US9517533B2 ## CPC - B23K 31/125: {Weld quality monitoring} - B23K 26/03: Observing, e.g. monitoring, the workpiece - B23K 26/21: by welding - B23K 26/24: Seam welding - G01B 11/30: for measuring roughness or irregularity of surfaces - B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS ## Abstract A welding laser beam (L1) is radiated along welding loci (C11, C12) set in workpieces (W1, W2), or an inspection laser beam (L5) is radiated along scanning loci (C51, C52) set in a molten pool (Y1) of the workpieces that are molten by radiation of the welding laser beam, a returned light beam (L2) including reflection light from the molten pool, vapor light caused due to melting and evaporation of the workpieces, and thermal radiation light emitted from the molten pool is received, and a welding state of a welded portion of the workpieces is inspected based on an intensity of a returned light beam received in a first region inside the molten pool which is relatively close to a given point and an intensity of a returned light beam received in a second region inside the molten pool which is relatively spaced from the given point. ## Claims ### Claim 1 A welded portion inspection apparatus that inspects a welding state of a welded portion formed at the time when a plurality of workpieces is welded, the welded portion inspection apparatus comprising: a laser beam radiation portion that radiates a welding laser beam several times along one welding locus set in the workpieces so as to weld the workpieces, or radiates an inspection laser beam several times along one scanning locus set in a molten pool of the workpieces that are molten by the welding laser beam; a laser-receiving sensor that receives a returned light beam including at least one of reflection light of the welding laser beam or the inspection laser beam radiated by the laser beam radiation portion, the reflection light being reflected from the molten pool of the workpieces, vapor light caused due to melting and evaporation of the workpieces, and thermal radiation light emitted from the molten pool of the workpieces; and a measuring instrument that monitors an intensity of a returned light beam received by the laser-receiving sensor in a first region inside the molten pool of the workpieces which is relatively close to a given point and an intensity of a returned light beam received by the laser-receiving sensor in a second region inside the molten pool of the workpieces which is relatively spaced from the given point, in order to inspect a welding state of a welded portion of the workpieces. ### Claim 2 (depends on 1) The welded portion inspection apparatus according to claim 1, wherein: the measuring instrument inspects the welding state of the welded portion of the workpieces based on a ratio between the intensity of the returned light beam received by the laser-receiving sensor in the first region and the intensity of the returned light beam received by the laser-receiving sensor in the second region. ### Claim 3 (depends on 1) The welded portion inspection apparatus according to claim 1, wherein: the welding locus of the welding laser beam or the scanning locus of the inspection laser beam has a closed loop shape or a spiral shape. ### Claim 4 (depends on 3) The welded portion inspection apparatus according to claim 3, wherein: the welding locus of the welding laser beam or the scanning locus of the inspection laser beam has a round shape or an elliptical shape. ### Claim 5 (depends on 3) The welded portion inspection apparatus according to claim 3, wherein: the given point is a welding center of the workpieces. ### Claim 6 (depends on 1) The welded portion inspection apparatus according to claim 1, wherein: the measuring instrument inspects the welding state of the welded portion of the workpieces based on an average intensity of the returned light beam received by the laser-receiving sensor in the first region and an average intensity of the returned light beam received by the laser-receiving sensor in the second region. ### Claim 7 A welded portion inspection method for inspecting a welding state of a welded portion formed at the time when a plurality of workpieces is welded, the welded portion inspection method comprising: radiating a welding laser beam several times along one welding locus set in the workpieces so as to weld the workpieces, or radiating an inspection laser beam several times along one scanning locus set in a molten pool of the workpieces that are molten by the welding laser beam; receiving a returned light beam including at least one of reflection light of the welding laser beam or the inspection laser beam which is reflected from the molten pool of the workpieces, vapor light caused due to melting and evaporation of the workpieces, and thermal radiation light emitted from the molten pool of the workpieces; and inspecting a welding state of a welded portion of the workpieces based on an intensity of a returned light beam received in a first region inside the molten pool of the workpieces which is relatively close to a given point and an intensity of a returned light beam received in a second region inside the molten pool of the workpieces which is relatively spaced from the given point. ### Claim 8 (depends on 7) The welded portion inspection method according to claim 7, wherein: in the of the welding state, the welding state of the welded portion of the workpieces is inspected based on a ratio between the intensity of the returned light beam received in the first region and the intensity of the returned light beam received in the second region. ### Claim 9 (depends on 7) The welded portion inspection method according to claim 7, wherein: the welding locus of the welding laser beam or the scanning locus of the inspection laser beam has a closed loop shape or a spiral shape. ### Claim 10 (depends on 9) The welded portion inspection method according to claim 9, wherein: the welding locus of the welding laser beam or the scanning locus of the inspection laser beam has a round shape or an elliptical shape. ### Claim 11 (depends on 9) The welded portion inspection method according to claim 9, wherein: the given point is a welding center of the workpieces. ### Claim 12 (depends on 7) The welded portion inspection method according to claim 7, wherein: in the inspecting of the welding state, the welding state of the welded portion of the workpieces is inspected based on an average intensity of the returned light beam received in the first region and an average intensity of the returned light beam received in the second region.