# US 10,479,407 B2 · Metal pipe and structural member using metal pipe for vehicle > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,479,407 B2 - Document ID: US10479407B2 - Status: Granted - Kind: B2 - Application number: 16/301,780 - Filed: 2017-06-05 - Published: 2019-05-23 - Granted: 2019-11-19 - Earliest claimed: 2016-06-07 - Assignees: Nippon Steel Corporation - Applicants: Nippon Steel & Sumitomo Metal Corporation - Inventors: Satoshi Hirose; Yuichi Ishimori; Hiroshi Fukuchi - Web page: https://patentgrep.com/patent/US10479407B2 ## CPC - B62D 21/08: built up with interlaced cross members - B60R 19/04: formed from more than one section {in a side-by-side arrangement} - B62D 21/15: having impact absorbing means, e.g. a frame designed to permanently or temporarily change shape or dimension upon impact with another body (bumpers B60R19/02; shock absorbers in general F16F) - B62D 23/005: {with integrated chassis in the whole shell, e.g. meshwork, tubes, or the like (B62D33/044 takes precedence)} - B62D 29/007: {predominantly of special steel or specially treated steel, e.g. stainless steel or locally surface hardened steel} - C21D 9/08: for tubular bodies or pipes - C21D 2221/00: Treating localised areas of an article - B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M) - B60R: VEHICLES, VEHICLE FITTINGS, OR VEHICLE PARTS, NOT OTHERWISE PROVIDED FOR - C21D: MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING (surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by this subclass C23F17/00; unidirectional solidification of eutectic materials or unidirectional demixing of eutectoid materials C30B) ## Abstract A metal pipe includes a pair of side walls facing each other and having a height H, a top portion connected to an upper edge of each of the pair of side walls, and a bottom portion connected to a lower edge of each of the pair of side walls. The metal pipe has a length six times the height H of the side walls or more. Each side wall pair includes a high-strength portion and a pair of low-strength portions, the low strength portions sandwiching the high strength portion. A high-strength portion dimension is not less than ⅔H and not more than 3H as measured longitudinally of the metal pipe, the high-strength portions forming opposite portions of the side wall pairs. The low-strength portion yield strength is 60 to 85% of that of the high-strength portion, whose yield strength is not less than 500 MPa. ## Claims ### Claim 1 A metal pipe comprising a quadrangular cross section and further comprising: a pair of side walls facing each other; a top portion connected to an upper edge of each of the pair of side walls; and a bottom portion connected to a lower edge of each of the pair of side walls, the metal pipe having a dimension six times a height H of a higher one of the pair of side walls or more as measured in a longitudinal direction of the metal pipe, each of the pair of side walls including: a high-strength portion having a dimension not less than ⅔H and not more than 3H as measured in the longitudinal direction of the metal pipe, the high-strength portions forming opposite portions of the pair of side walls, each high-strength portion having a yield strength not less than 500 MPa, and a pair of low-strength portions sandwiching each of the high-strength portions as determined along the longitudinal direction of the metal pipe, each of the pair of low-strength portions having a yield strength of 60 to 85% of that of the high-strength portion, wherein a dimension of each of the low-strength portions as measured in the longitudinal direction of the metal pipe is 3/5H or more. ### Claim 2 (depends on 1) The metal pipe according to claim 1, wherein each of the high-strength portions is located in a middle of the metal pipe as measured in the longitudinal direction of the metal pipe. ### Claim 3 (depends on 2) The metal pipe according to claim 2, wherein the metal pipe is curved to protrude on the top portion. ### Claim 4 (depends on 1) The metal pipe according to claim 1, wherein the metal pipe is curved to protrude on the top portion. ### Claim 5 A vehicle comprising: a structural member comprising a metal pipe with a quadrangular cross section, the metal pipe further comprising: a pair of side walls facing each other; a top portion being connected to an upper edge of each of the pair of side walls and located on an outside of the vehicle; and a bottom portion being connected to a lower edge of each of the pair of side walls and located toward an interior of the vehicle, wherein at least one of the side walls, top portion and bottom portion includes two connections to be joined to another member, the connections being separated by a distance six times a height H of a higher one of the pair of side walls or more as measured in a longitudinal direction of the metal pipe, each of the pair of side walls includes: a high-strength portion located between the connections and having a dimension not less than ⅔H and not more than 3H as measured in the longitudinal direction of the metal pipe, the high-strength portions forming opposite portions of the pair of side walls, each high-strength portion having a yield strength not less than 500 MPa, and a pair of low-strength portions located between the connections and sandwiching each of the high-strength portions as determined along the longitudinal direction of the metal pipe, each of the pair of low-strength portions having a yield strength of 60 to 85% of that of the high-strength portion, wherein a dimension of each of the low-strength portions of the metal pipe as measured in the longitudinal direction of the metal pipe is 3/5H or more. ### Claim 6 (depends on 5) The vehicle according to claim 5, wherein each of the high-strength portions of the metal pipe is located midway between the two connections. ### Claim 7 (depends on 6) The vehicle according to claim 6, wherein the metal pipe is curved to protrude on the top portion. ### Claim 8 (depends on 5) The vehicle according to claim 5, wherein the metal pipe is curved to protrude on the top portion. ### Claim 9 (depends on 5) The vehicle according to claim 5, wherein the vehicle structural member forms part of a vehicle body of the vehicle, and the vehicle body has a space-frame structure.