# US 7,073,701 B2 · Method of joining two members by friction stir welding > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,073,701 B2 - Document ID: US7073701B2 - Status: Granted - Kind: B2 - Application number: 10/600,573 - Filed: 2003-06-23 - Published: 2004-04-08 - Granted: 2006-07-11 - Earliest claimed: 1996-03-19 - Assignees: Hitachi, Ltd. - Inventors: Kinya Aota; Tsuyoshi Takenaka; Yasuo Ishimaru - Web page: https://patentgrep.com/patent/US7073701B2 ## CPC - B61D 17/043: {connections between superstructure sub-units (for road vehicles B62D27/00)} - B23K 20/122: {using a non-consumable tool, e.g. friction stir welding} - B23K 20/123: {Controlling or monitoring the welding process} - B23K 20/126: {Workpiece support, i.e. backing or clamping} - B23K 33/00: Specially-profiled edge portions of workpieces for making soldering or welding connections; Filling the seams formed thereby - B23K 33/004: {Filling of continuous seams} - E04C 2/08: of metal, e.g. sheet metal (E04C2/26 takes precedence) - E04C 2/36: spaced apart by transversely-placed strip material, e.g. honeycomb panels (honeycomb or other core members for layered products B32B) - E04C 2/543: {Hollow multi-walled panels with integrated webs} - B23K 2101/045: {Hollow panels} - Y10T 428/12: All metal or with adjacent metals - Y10T 428/1234: Honeycomb, or with grain orientation or elongated elements in defined angular relationship in respective components [e.g., parallel, inter- secting, etc.] - Y10T 428/12375: having member which crosses the plane of another member [e.g., T or X cross section, etc.] - Y10T 428/12382: Defined configuration of both thickness and nonthickness surface or angle therebetween [e.g., rounded corners, etc.] - Y10T 428/12493: Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.] - Y10T 428/192: Sheets or webs coplanar - Y10T 428/24777: Edge feature - B61D: BODY DETAILS OR KINDS OF RAILWAY VEHICLES (vehicles in general B60; adaptation of vehicles to special systems B61B; underframes B61F) - 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 - E04C: STRUCTURAL ELEMENTS; BUILDING MATERIALS (for bridges E01D; specially designed for insulation or other protection E04B; elements used as building aids E04G; for mining E21; for tunnels E21D; structural elements with broader range of application than for building engineering F16, particularly F16S) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract This invention provides a configuration of a joint that allows a satisfactory welded joint to be formed with reduced deformation of the joint region when two-face structures (panels) are friction-welded end to end. The panels 31, 32 each have two substantially parallel plates 33, 34 and a third member 35 connecting the two plates 33, 34. The end portions of the plates 33, 34 of one panel 32 are friction-welded to the end portions of the plates 33, 34 of the other panel 32. At least one of the panels has a plate 36 at its end for connecting the plates 33 and 34 and has a rigidity to support a pressing force produced during the friction welding. ## Claims ### Claim 1 A method of joining two members by friction stir welding, comprising the steps of: arranging said members so that respective joint faces thereof are adjacent each other, providing a joint region, and inserting, at one side of said members, a friction stir welding probe of material harder than that of said members into both said members at the location of the adjacent joint faces thereof, and rotating said probe so as to effect friction stir welding to join said members, forming a joining region, wherein at least one of said members has, at said one side thereof, a raised portion which is adjacent said joint face thereof and protrudes towards the probe so as to make the joint region thicker than a remaining region of each member, said raised portion being contacted by said probe during the friction stir welding and at least partially removed by the probe, and the method further includes cuffing off the part of said raised portion remaining after the friction stir welding by said probe. ### Claim 2 (depends on 1) A method according to claim 1, wherein a gap between said joint faces of the members before welding is filled with the material of the raised portion during the welding. ### Claim 3 (depends on 2) A method according to claim 2, wherein, following the friction stir welding and the cutting off of said part of said raised portion, said members, as seen in cross-section across the joining region, have substantially flat and mutually flush joined surfaces at said one side thereof. ### Claim 4 (depends on 2) A method according to claim 2, wherein the method comprises substantially wholly removing said raised portion after the friction stir welding so that said members, as seen in cross-section across the joining region, have substantially flat and mutually flush joined surfaces at said one side thereof. ### Claim 5 (depends on 4) A method according to claim 4, wherein both of said members are provided respectively with said raised portion, and the method comprises substantially wholly removing both of the raised portions so that said members, as seen in cross-section across the joining region, have substantially flat and mutually flush surfaces at said one side thereof. ### Claim 6 (depends on 5) A method according to claim 5, wherein said raised portion, prior to the friction stir welding, stands up higher than any other part of the member having the raised portion, at said one side of the members. ### Claim 7 (depends on 5) A method according to claim 5, wherein said raised portion is constituted by a local thickening of the member having the raised portion, at said joint face thereof. ### Claim 8 (depends on 7) A method according to claim 7, wherein each of said members is provided with said raised portion, the respective raised portions substantially abutting each other when said joint faces are adjacent each other, and said probe contacts and at least partially removes both said raised portions. ### Claim 9 (depends on 8) A method according to claim 8, wherein each raised portion is in one piece with the member on which it is provided. ### Claim 10 (depends on 8) A method according to claim 8, wherein said raised portion is a separate piece connected to said member on which it is provided prior to the friction stir welding. ### Claim 11 (depends on 8) A method according to claim 8, wherein said raised portion is on one member and extends over the other member when said members are arranged for welding, and said probe penetrates through said raised portion when inserted into the members. ### Claim 12 (depends on 11) A method according to claim 11, wherein by the friction stir welding, a welding bead is formed at a region of said two members beneath the location of said raised portion. ### Claim 13 (depends on 12) A method according to claim 12, wherein said two members are first and second metal panels which are joined together edge-to-edge to form a panel structure by the friction stir welding, each of said first and second panels having at said one side a first face sheet and at its opposite side a web parallel to and spaced from said first face sheet, and having at least one cross-member connecting said face sheet and said web, said first face sheets of said first and second panels being joined directly by a weld joint, at which a weld bead is formed by the friction stir welding, said cross-member of at least one of said panels constituting a weld-support cross-member which has one end located at an edge of the panel at which said weld joint is provided, extends across the panel in a transverse direction which is at an angle to said first face sheet of the panel, and has a thickness and location such that said welding bead lies at least partly in a projection area of said cross-member in said transverse direction. ### Claim 14 (depends on 13) A method according to claim 13, wherein each of said first and second panels has said weld-support cross-member at respective edges at which said weld joint is provided, the respective weld-support cross-members lying alongside each other. ### Claim 15 (depends on 14) A method according to claim 14, including forming two of said weld joints at opposite sides of the panel structure by twice performing the friction stir welding, said two weld joints lying respectively at opposite ends of said weld-support cross-members. ### Claim 16 (depends on 15) A method according to claim 15, wherein said web of each of said first and second panels is a second face sheet. ### Claim 17 (depends on 16) A method according to claim 16, wherein, at said edges of said first and second panels at which said at least one weld joint is formed, said first and second face sheets thereof are comprised of a sheet member and a portion of a reinforcing edge body which is connected by brazing to said sheet member, said welding bead is formed in both said sheet member and said reinforcing edge body, and said reinforcing edge body provides said weld-support cross-member. ### Claim 18 (depends on 13) A method according to claim 13, wherein said first face sheet of one of said panels has a projecting edge portion and the other of said panels has a recess receiving said projecting edge portion. ### Claim 19 (depends on 18) A method according to claim 18, wherein said web of one of said first and second metal panels also has a projecting edge portion and said web of the other of said panels has a recess receiving said projecting edge portion of said web of said one of said first and second metal panels. ### Claim 20 (depends on 1) A method according to claim 1, wherein the method comprises substantially wholly removing said raised portion after the friction stir welding so that said members, as seen in cross-section across the joining region, have substantially flat and mutually flush joined surfaces at said one side thereof. ### Claim 21 (depends on 20) A method according to claim 20, wherein both of said members are provided respectively with said raised portion, and the method comprises substantially wholly removing both of the raised portions so that said members, as seen in cross-section across the joining region, have substantially flat and mutually flush surfaces at said one side thereof. ### Claim 22 (depends on 1) A method according to claim 1, wherein said raised portion, prior to the friction stir welding, stands up higher than any other part of the member having the raised portion, at said one side of the members. ### Claim 23 (depends on 1) A method according to claim 1, wherein said raised portion is constituted by a local thickening of the member having the raised portion, at said joint face thereof. ### Claim 24 (depends on 1) A method according to claim 1, wherein each of said members is provided with said raised portion, the respective raised portions substantially abutting each other when said joint faces are adjacent each other, and said probe contacts and at least partially removes both said raised portions. ### Claim 25 (depends on 1) A method according to claim 1, wherein each raised portion is in one piece with the member on which it is provided. ### Claim 26 (depends on 1) A method according to claim 1, wherein said raised portion is a separate piece connected to said member on which it is provided prior to the friction stir welding. ### Claim 27 (depends on 1) A method according to claim 1, wherein said raised portion is on one member and extends over the other member when said members are arranged for welding, and said probe penetrates through said raised portion when inserted into the members. ### Claim 28 (depends on 1) A method according to claim 1, wherein by the friction stir welding, a welding bead is formed at a region of said two members beneath the location of said raised portion. ### Claim 29 (depends on 1) A method according to claim 1, wherein said two members are first and second metal panels which are joined together edge-to-edge to form a panel structure by the friction stir welding, each of said first and second panels having at said one side a first face sheet and at its opposite side a web parallel to and spaced from said first face sheet, and having at least one cross-member connecting said face sheet and said web, said first face sheets of said first and second panels being joined directly by a weld joint, at which a weld bead is formed by the friction stir welding, said cross-member of at least one of said panels constituting a weld-support cross-member which has one end located at an edge of the panel at which said weld joint is provided, extends across the panel in a transverse direction which is at an angle to said first face sheet of the panel, and has a thickness and location such that said welding bead lies at least partly in a projection area of said cross-member in said transverse direction. ### Claim 30 (depends on 29) A method according to claim 29, wherein each of said first and second panels has said weld-support cross-member at respective edges at which said weld joint is provided, the respective weld-support cross-members lying alongside each other. ### Claim 31 (depends on 30) A method according to claim 30, including forming two of said weld joints at opposite sides of the panel structure by twice performing the friction stir welding, said two weld joints lying respectively at opposite ends of said weld-support cross-members. ### Claim 32 (depends on 31) A method according to claim 31, wherein said web of each of said first and second panels is a second face sheet. ### Claim 33 (depends on 32) A method according to claim 32, wherein, at said edges of said first and second panels at which said at least one weld joint is formed, said first and second face sheets thereof are comprised of a sheet member and a portion of a reinforcing edge body which is connected by brazing to said sheet member, said welding bead is formed in both said sheet member and said reinforcing edge body, and said reinforcing edge body provides said weld-support cross-member. ### Claim 34 (depends on 29) A method according to claim 29, wherein said first face sheet of one of said panels has a projecting edge portion and the other of said panels has a recess receiving said projecting edge portion. ### Claim 35 (depends on 34) A method according to claim 34, wherein said web of one of said first and second metal panels also has a projecting edge portion and said web of the other of said panels has a recess receiving said projecting edge portion of said web of said one of said first and second metal panels.