Manufacturing method for structural members

Abstract

To provide a method for manufacturing a structural member capable of manufacturing a high-quality structural member by easily and smoothly joining extruded materials to each other.SOLUTION: A method for manufacturing a structural member includes the steps of: disposing a plurality of extruded panels 11A to 11D provided with surplus regions Ar at both ends in advance on a base plate 31 with edge portions abutted against each other; fixing the extruded panels 11A to 11D to the base plate 31 by bolts 39 inserted into through-holes 19 of the surplus regions Ar, friction-stir-welding the edge portions of the extruded panels 11A to 11D to each other on a front surface side so that a start point and an end point are disposed on the surplus regions Ar; reversing the plurality of extruded panels 11A to 11D to dispose again them on the base plate 31; fixing the extruded panels 11A to 11D to the base plate 31 by the bolts 39 inserted into the through-holes 19 of the surplus regions Ar; friction-stir-welding the edge portions of the extruded panels 11A to 11D to each other on the back surface side so that the start point and the end point are disposed on the surplus regions Ar; and removing the surplus regions Ar by detaching the plurality of the extruded panels 11A to 11D joined to each other from the base plate 31.SELECTED DRAWING: Figure 6A

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a structural member.

Background Art

[0002] Conventionally, there has been a demand for improving the safety of vehicle occupants, and for this purpose, the strength of the vehicle body has been improved. On the other hand, against the backdrop of the deepening of problems such as global warming, the movement to improve the fuel efficiency of automobiles has been accelerating. It is known that weight reduction of the vehicle body is effective for improving fuel efficiency. In addition, for the above-mentioned environmental improvement, the development of vehicles that run on electricity (including electric vehicles, hybrid vehicles, etc.) and devices such as self-propelled robots has been progressing. In such a battery system mounted on a vehicle or device, a configuration may be adopted in which a large number of batteries (cells, battery cells) are housed in a battery tray made of a structural member in which an aluminum extruded material is joined.

[0003] By the way, as a technique for joining members such as extruded materials, it is known to butt the members together and perform friction stir joining with a friction stir tool. In this friction stir joining, there is a possibility that an incomplete joining portion where the joining is insufficient may occur at the start and end. Therefore, when friction stir joining members, a tab plate is arranged on the extension line at both ends of the butting portion of the members, and the start and end of the friction stir joining are positioned on the tab plate, so as to suppress the occurrence of incomplete joining portions at the joint part (for example, see Patent Documents 1 to 3).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

[0005] However, in techniques using tab plates, the tab plates must be positioned and placed on the member without gaps or steps, which is time-consuming. In addition, the joining conditions may change at the boundary between the member and the tab plate, potentially degrading the joining quality at both ends of the joint. Furthermore, when joining the front and back of a butt joint, the tab plates must be repositioned and placed at both ends of the joint, which adds to the joining process.

[0006] Therefore, the present invention aims to provide a method for manufacturing structural members that enables the easy and smooth joining of extruded materials to produce high-quality structural members. [Means for solving the problem]

[0007] This invention consists of the following configuration. A manufacturing method for producing a structural member by joining the edges of multiple extruded panels made of extruded material, A first arrangement step involves arranging a plurality of the extruded panels, each having an excess region with through holes pre-provided at both ends, on a base plate with their edges butted together, A first fixing step involves inserting a fastening member into the through hole in the excess area and fixing the extruded panel to the base plate with the fastening member, A first joining step in which, on the surface side of the extruded panel, the abutting edges of the extruded panel are frictionally stirred and joined together using a friction stirring tool such that the start and end points are the excess region, A second placement step involves releasing the fixation of the multiple extruded panels, which are joined on the surface side, to the base plate, inverting them, and then repositioning the extruded panels on the base plate. A second fixing step involves inserting a fastening member into the through hole in the excess area and fixing the extruded panel to the base plate with the fastening member, A second joining step in which, on the back side of the extruded panel, the abutting edges of the extruded panel are frictionally stirred and joined together using a friction stirring tool, such that the start and end points are the excess region, A process of removing excess areas by removing the multiple extruded panels that are joined together from the base plate and removing the excess areas, including, A method for manufacturing structural members. [Effects of the Invention]

[0008] According to the present invention, high-quality structural members can be manufactured by easily and smoothly joining extruded materials together. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a perspective view of a structural member manufactured by the manufacturing method of the structural member in this example. [Figure 2] Figure 2 is an enlarged front view of a portion of the structural member shown in Figure 1. [Figure 3] Figure 3 is a perspective view illustrating the jig used in the manufacturing method of the structural member in this example. [Figure 4] Figure 4 is a plan view of the jig shown in Figure 3. [Figure 5] Figure 5 is a cross-sectional view along the VV line in Figure 4. [Figure 6A] Figure 6A is an explanatory diagram illustrating the procedure for joining extruded panels together to form a structural member. [Figure 6B] Figure 6B is an explanatory diagram illustrating the procedure for joining extruded panels together to form a structural member. [Figure 6C] Figure 6C is an explanatory diagram illustrating the procedure for joining extruded panels together to form a structural member. [Figure 6D] Figure 6D is an explanatory diagram illustrating the procedure for joining extruded panels together to form a structural member. [Figure 6E] Figure 6E is an explanatory diagram illustrating the procedure for joining extruded panels together to form a structural member. [Figure 6F]FIG. 6F is an explanatory diagram for explaining the procedure of joining extrusion panels to form a structural member. [Figure 6G] FIG. 6G is an explanatory diagram for explaining the procedure of joining extrusion panels to form a structural member. [Figure 6H] FIG. 6H is an explanatory diagram for explaining the procedure of joining extrusion panels to form a structural member.

Embodiments for Carrying out the Invention

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view of a structural member 100 manufactured by the manufacturing method of the structural member of this example. FIG. 2 is a front view of a part of the structural member 100 shown in FIG. 1 enlarged.

[0011] As shown in FIGS. 1 and 2, the structural member 100 manufactured by the manufacturing method of the structural member according to this configuration example is a plate-shaped structure, and is composed of extrusion panels 11A to 11D made of a plurality (in this example, four as an example) of extruded materials. The structural member 100 is configured by joining the edges along the extrusion direction of the extrusion panels 11A to 11D to each other.

[0012] As the extrusion panels 11A to 11D, plate-shaped extruded materials made of aluminum or an aluminum alloy are used. As the aluminum alloy used as the extrusion panels 11A to 11D, aluminum alloys of the 5000 series, 6000 series, 7000 series, etc. according to JIS or AA standards are preferable in terms of having excellent strength and being able to be made thinner. The hollow extruded profiles of these aluminum alloys can preferably use those manufactured by appropriately combining heat treatment processes such as casting (DC casting method or continuous casting method), homogenization heat treatment, hot extrusion, solution treatment and quenching treatment, and artificial aging treatment if necessary. According to this, the structural member 100 can be made into a high-strength configuration while being lightweight.

[0013] Each of the extruded panels 11A to 11D has one or more hollow sections 13 formed in the center of its thickness. The extruded panels 11A to 11D are, for example, thin plates with a thickness of 15 mm or less. Preferably, the thickness of the hollow sections 13 in the extruded panels 11A to 11D is about half the thickness of the extruded panels 11A to 11D.

[0014] The structural member 100 shown in Figure 2 is joined at a joint 21 where the edges of the extruded panels 11B and 11C are butted together. Similarly, the extruded panels 11A and 11B, and the extruded panels 11C and 11D are also joined. The extruded panels 11A to 11D have protruding pieces 15 and stepped portions 17 on the edges facing each other at the joint 21. These pairs of protruding pieces 15 are overlapped in the thickness direction. At each joint 21, the protruding piece 15 of one extruded panel abuts against the wall portion 17a forming the stepped portion 17 of the other extruded panel, and the butt joints on the front and back surfaces are joined. As a result, the joint 21 has a first joint portion 23 on the front surface and a second joint portion 25 on the back surface. The first joint 23 and the second joint 25 are joined by friction stir welding using a friction stir tool.

[0015] In this configuration, the structural member 100 has butt joints between the extruded panels 11A to 11D on the front and back sides, with a balanced and stable joint strength at the first joint 23 on the front side and the second joint 25 on the back side. Therefore, sufficient strength can be ensured at the joint portion 21 of the structural member 100 and its surrounding area.

[0016] Next, we will describe the jig 30 used when joining the extruded panels 11A to 11D together. Figure 3 is a perspective view illustrating the jig 30 used in the manufacturing method of the structural member in this example. Figure 4 is a plan view of the jig 30 shown in Figure 3. Figure 5 is a cross-sectional view along the VV line in Figure 4.

[0017] As shown in Figures 3 to 5, the jig 30 has a base plate 31, a plurality of spacers 33, and a plurality of backing plates 35.

[0018] The base plate 31 is formed as a flat plate with a smooth upper surface. The base plate 31 is formed as a rectangle in plan view, and the extruded panels 11A to 11D, which are joined together, are arranged on its upper surface along the longitudinal direction of the base plate 31. These extruded panels 11A to 11D are aligned so that their extrusion directions are aligned. The base plate 31 has a plurality of bolt holes 31a consisting of female threads, spaced apart in the longitudinal direction, near its short edge. Bolts (fastening members) 39 are fastened to these bolt holes 31a to fix the extruded panels 11A to 11D to the base plate 31.

[0019] Each spacer 33 is a flat plate material and is inserted into the hollow section 13 from both ends of the extrusion direction of the extrusion panels 11A to 11D. Each spacer 33 is inserted into the hollow section 13 of the extrusion panels 11A to 11D with a portion of it protruding from the end of the extrusion direction of the extrusion panels 11A to 11D. Each spacer 33 has an insertion hole 33a that penetrates through to the front and back.

[0020] Each backing plate 35 is a flat plate material and is positioned on the upper surface at both ends of the extrusion direction of the extrusion panels 11A to 11D. The backing plates 35 have through holes 35a formed in them corresponding to the hollow portions 13 of each of the extrusion panels 11A to 11D. Here, the total number of through holes 35a (6) of the backing plates 35 positioned on one side of the extrusion direction is the same as the number of hollow portions 13. In other words, the backing plate 35 positioned on the upper surface of the extrusion panels 11A and 11D, which have one hollow portion 13, has one through hole 35a, and the backing plates 35 positioned on the upper surface of the extrusion panels 11B and 11C, which have two hollow portions 13, have two through holes 35a, each spaced at the same pitch as the hollow portions 13.

[0021] Next, we will describe the case in which the structural member 100 is manufactured using the jig 30 described above. Figures 6A to 6H are explanatory diagrams illustrating the procedure for joining extruded panels 11A to 11D together to form a structural member 100.

[0022] (1st placement process) As shown in Figure 6A, excess regions Ar are provided in advance at both ends of each extrusion panel 11A to 11D in the extrusion direction, and through holes 19 are formed in these excess regions Ar. Preferably, the dimension W of the excess region Ar in the joining direction by the friction stir tool is set to be 10 times or more the wall thickness at the joining point. The through holes 19 are formed, for example, in the center of the excess region Ar in the joining direction at the center of the width direction of the hollow portion 13 (see Figure 4). The extrusion panels 11A to 11D, each having an excess region Ar with a through hole 19, are arranged on the base plate 31 parallel to the extrusion direction, and the edges of each extrusion panel 11A to 11D in the direction of alignment are butted together. The bolt holes 31a of the base plate 31 (see Figure 5) are formed in positions that communicate with the through holes 19 of the multiple extrusion panels 11A to 11D arranged on the upper surface of the base plate 31. The extruded panels 11A to 11D are then placed on the base plate 31 with their through holes 19 communicating with the bolt holes 31a of the base plate 31.

[0023] (1st fixing process) As shown in Figure 6B, spacers 33 are inserted into the hollow portion 13 from both ends in the extrusion direction of the extrusion panels 11A to 11D placed on the base plate 31, and the insertion holes 33a of these spacers 33 are connected to the through holes 19 of the extrusion panels 11A to 11D.

[0024] Furthermore, backing plates 35 are placed on the upper surfaces of the extruded panels 11A to 11D that are opposite the base plate 31 at both ends, and the insertion holes 35a of these backing plates 35 are connected to the through holes 19 of the extruded panels 11A to 11D. Then, bolts 39 are inserted from above (perpendicular to the panel surface) into the mutually connected insertion holes 33a, 35a and through holes 19 and fastened to the bolt holes 31a of the base plate 31. This fixes the extruded panels 11A to 11D, which are placed on the base plate 31, to the base plate 31. At this time, since spacers 33 are inserted into the hollow portions 13 of the extruded panels 11A to 11D, deformation of the hollow portions 13 due to the fastening of the bolts 39 is suppressed. In addition, the backing plates 35 suppress damage to the extruded panels 11A to 11D caused by contact with the bolts 39. The extruded panels 11A to 11D are then fastened and fixed to the base plate 31 with bolts 39, pressing them against the base plate 31 and arranging them in a smooth, even position relative to each other.

[0025] (1st joining process) As shown in Figure 6C, the joint portion 21, which is formed by the abutting of the edges of the extruded panels 11A to 11D, is friction-stir-welded on its surface side using a friction stir tool. As a result, each of the extruded panels 11A to 11D is joined to each other on its surface side, with a first joint portion 23 formed at the joint portion 21. Here, the friction stir welding is performed so that the start and end points of the friction stir tool are in the excess region Ar. As a result, the start and end points Pse of the friction stir welding of the first joint portion 23 are positioned in the aforementioned excess region Ar.

[0026] (Second placement process) Loosen the bolts 39 that secure the extruded panels 11A to 11D to release them from the base plate 31, and remove the spacers 33 and backing plates 35. Once the extruded panels 11A to 11D have been removed from the base plate 31, as shown in Figure 6D, invert the extruded panels 11A to 11D, which are joined at the first joint 23 on the surface side, and place them back on the base plate 31. Then, connect the through holes 19 of the extruded panels 11A to 11D to the bolt holes 31a (see Figure 5) of the base plate 31.

[0027] (Second fixing process) As shown in Figure 6E, spacers 33 are inserted into the hollow portion 13 from both ends of the extrusion direction of the extruded panels 11A to 11D, and backing plates 35 are placed on the upper surfaces opposite to the base plate 31 at both ends of the extrusion direction of the extruded panels 11A to 11D, so that the insertion holes 33a and 35a of the spacers 33 and backing plates 35 are connected to the through holes 19 (Figure 6D) of the extruded panels 11A to 11D. Then, bolts 39 are inserted from above (perpendicular to the plate surface) into the mutually connected insertion holes 33a, 35a and through holes 19 and fastened to the bolt holes 31a of the base plate 31. In this way, the extruded panels 11A to 11D placed on the base plate 31 are fixed to the base plate 31. At this time as well, deformation of the hollow portion 13 due to the fastening of the bolts 39 is suppressed by the spacers 33, and damage to the extruded panels 11A to 11D due to contact with the bolts 39 is suppressed by the backing plates 35. Furthermore, by fixing the extruded panels 11A to 11D to the base plate 31 with bolts 39, each extruded panel 11A to 11D is pressed against the base plate 31, and the warp that occurred when the surface side was joined in the first joining process is returned to the opposite side, resulting in a smooth arrangement.

[0028] (Second joining process) As shown in Figure 6F, the joint portions 21, which are the abutting points between the edges, are friction-stir-welded on the back sides of the extruded panels 11A to 11D using a friction stir tool. As a result, a second joint portion 25 is formed at the joint portion 21 of each extruded panel 11A to 11D, and they are joined to each other on the back sides. In this case as well, the friction stir welding is performed so that the start and end points of the friction stir tool are in the excess region Ar. As a result, the start and end points Pse of the friction stir welding of the second joint portion 25 are positioned in the excess region Ar.

[0029] (Excess area removal process) As shown in Figure 6F, loosen the bolts 39 that secure the extruded panels 11A to 11D, which are joined on both sides, to release the extruded panels 11A to 11D from the base plate 31, and remove the spacers 33 and backing plates 35. As shown in Figure 6G, once the extruded panels 11A to 11D have been removed from the base plate 31, as shown in Figure 6H, cut and remove the excess region Ar of the extruded panels 11A to 11D where the start and end Pse of the first joint 23 and the second joint 25 are formed, at their boundary. This results in a structural member 100 in which multiple extruded panels 11A to 11D are friction stir-bonded on both sides. The removed excess region Ar can be recycled, for example, and molded again into an extruded panel. At this time, the excess region Ar having the friction stir-bonded portion is made of the same material as the extruded panels 11A to 11D, and since there is no contamination with other metals, it can be molded again into an extruded panel without the need to remove impurities.

[0030] As explained above, according to the manufacturing method of structural members in this example, friction stir welding is performed such that the start and end points of friction stir welding using a friction stir tool are positioned in the excess regions Ar provided in advance at both ends of the extruded panels 11A to 11D, and the excess regions Ar are removed after welding. This suppresses the occurrence of incomplete joints in the joint portion 12 of the manufactured structural member 100. Furthermore, bolts 39 are inserted into the through holes 19 of the excess region Ar, and the extruded panels 11A to 11D are fixed to the base plate 31 with these bolts 39, allowing for stable friction stir welding. As a result, compared to a method in which tab plates are placed at the start and end points of friction stir welding, high-quality structural members 100 without incomplete joints can be easily manufactured. In other words, high-quality structural members 100 in which extruded panels 11A to 11D are joined on both sides can be easily manufactured while keeping costs down.

[0031] Furthermore, by setting the dimension W in the joining direction of the friction stir tool in the excess region Ar to more than 10 times the wall thickness at the joining point, the start and end points Pse of the friction stir joining by the friction stir tool can be smoothly positioned in the excess region, enabling the manufacture of high-quality structural members 100.

[0032] Furthermore, since spacers 33 are inserted into the hollow portions 13 of the extruded panels 11A to 11D and the extruded panels 11A to 11D are fixed to the base plate 31 with bolts 39, deformation in the hollow portions 13 when the bolts 39 are tightened can be suppressed.

[0033] Furthermore, the backing plate 35 can suppress the occurrence of scratches on the extruded panels 11A to 11D due to contact with the bolts 39. Moreover, the fastening force of the bolts 39 can be distributed, allowing the extruded panels 11A to 11D to be fixed to the base plate 31 in a stable state, and friction stir welding can be performed smoothly.

[0034] In the above embodiment, an example was given of manufacturing a structural member 100 by joining extruded panels 11A to 11D having hollow portions 13. However, the present invention is also applicable to manufacturing a structural member 100 by joining solid extruded panels 11A to 11D without hollow portions 13. In this case, the extruded panels 11A to 11D are fixed to the base plate 31 and friction stir-welded without using spacers 33.

[0035] Furthermore, in the above embodiment, the extruded panels 11A to 11D were fixed to the base plate 31 by bolts 39. However, the fixing of the extruded panels 11A to 11D to the base plate 31 is not limited to fastening with bolts 39, but may also be done by various fastening methods using clamps, pins, etc.

[0036] Thus, the present invention is not limited to the embodiments described above. It is also intended and within the scope of protection to be provided for the combination of each configuration of the embodiments, as well as for modifications and applications by those skilled in the art based on the description in the specification and well-known technology.

[0037] As described above, the following matters are disclosed in this specification: (1) A manufacturing method for producing a structural member by joining the edges of a plurality of extruded panels made of extruded material, A first arrangement step involves arranging a plurality of the extruded panels, each having an excess region with through holes pre-provided at both ends, on a base plate with their edges butted together, A first fixing step involves inserting a fastening member into the through hole in the excess area and fixing the extruded panel to the base plate with the fastening member, A first joining step in which, on the surface side of the extruded panel, the abutting edges of the extruded panel are frictionally stirred and joined together using a friction stirring tool such that the start and end points are the excess region, A second placement step involves releasing the fixation of the multiple extruded panels, which are joined on the surface side, to the base plate, inverting them, and then repositioning the extruded panels on the base plate. The fastening member is inserted into the through hole in the excess area, and the extruded panel is fastened by the fastening member. A second fixing step involves fixing the base plate, A second joining step in which, on the back side of the extruded panel, the abutting edges of the extruded panel are frictionally stirred and joined together using a friction stirring tool, such that the start and end points are the excess region, A process of removing excess areas by removing the multiple extruded panels that are joined together from the base plate and removing the excess areas, A method for manufacturing structural members, including According to this manufacturing method for structural members, friction stir welding is performed so that the start and end points of the friction stir welding using a friction stir tool are positioned in pre-prepared excess areas at both ends of the extruded panel, and the excess areas are removed after welding. This suppresses the occurrence of incomplete joints in the joints of the manufactured structural members. Furthermore, fastening members are inserted into through holes in the excess areas, and these fastening members are used to fix the extruded panel to the base plate, allowing for stable friction stir welding. As a result, compared to a method in which tab plates are placed at the start and end points of friction stir welding, high-quality structural members without incomplete joints can be easily manufactured. In other words, high-quality structural members in which extruded panels are joined on both sides can be easily manufactured while keeping costs down. (2) The method for manufacturing a structural member according to (1), wherein the dimensions of the excess region in the joining direction by the friction stirring tool are 10 times or more the thickness at the joining point. According to this method of manufacturing structural members, the start and end points of friction stir welding using a friction stir tool can be smoothly positioned in the surplus area, enabling the production of high-quality structural members. (3) The extruded panel has a hollow portion, A method for manufacturing a structural member according to (1) or (2), wherein in the first fixing step and the second fixing step, a spacer is inserted into the hollow portion at the fixing point of the extruded panel to the base plate by the fastening member. According to this manufacturing method for structural members, a spacer is inserted into the hollow portion and the extruded panel is fixed to the base plate by a fastening member, thereby suppressing deformation in the hollow portion when the fastening member is fastened. (4) The method for manufacturing a structural member according to (1) or (2), wherein in the first fixing step and the second fixing step, a backing plate is placed on the side opposite to the base plate at the point where the extruded panel is fixed to the base plate by the fastening member. (5) The method for manufacturing a structural member according to (3), wherein in the first fixing step and the second fixing step, a backing plate is placed on the side of the fixing location of the extruded panel that is opposite to the base plate. According to the manufacturing method of the structural members described in (4) and (5) above, the backing plate can suppress the occurrence of scratches on the extruded panel due to contact with the fastening member. In addition, the fastening force of the fastening member can be distributed, allowing the extruded panel to be fixed to the base plate in a stable state, and friction stir welding can be performed smoothly. [Explanation of Symbols]

[0038] 11A, 11B, 11C, 11D Extruded Panels 19 Through hole 23 1st joint 25 Second joint 31 Base plate 33 Spacers 35 backing plate 39 Bolts (fastening components) 100 Structural members Ar extra region Pse start and end

Claims

1. A manufacturing method for producing a structural member by joining the edges of multiple extruded panels made of extruded material, A first arrangement step involves arranging a plurality of the extruded panels, each having an excess region with through holes pre-provided at both ends, on a base plate with their edges butted together, A first fixing step involves inserting a fastening member into the through hole in the excess area and fixing the extruded panel to the base plate with the fastening member, A first joining step in which, on the surface side of the extruded panel, the abutting edges of the extruded panel are frictionally stirred and joined together using a friction stirring tool, such that the start and end points are the excess region, A second placement step involves releasing the fixation of the multiple extruded panels, which are joined on the surface side, to the base plate, inverting them, and then repositioning the extruded panels on the base plate. A second fixing step involves inserting a fastening member into the through hole in the excess area and fixing the extruded panel to the base plate with the fastening member, A second joining step is to friction stir join the abutting edges of the extruded panels on the back side of the extruded panel using a friction stir tool, such that the start and end points are in the excess region. A process of removing excess areas by removing the multiple extruded panels that are joined together from the base plate and removing the excess areas, including, A method for manufacturing structural members.

2. The excess region is such that the dimension in the joining direction by the friction stirring tool is 10 times or more the wall thickness at the joining point. A method for manufacturing a structural member according to claim 1.

3. The extruded panel has a hollow portion, In the first fixing step and the second fixing step, a spacer is inserted into the hollow portion at the fixing point of the extruded panel to the base plate by the fastening member. A method for manufacturing a structural member according to claim 1.

4. In the first fixing step and the second fixing step, a backing plate is placed on the side opposite to the base plate at the point where the extruded panel is fixed to the base plate by the fastening member. A method for manufacturing a structural member according to claim 1 or 2.

5. In the first fixing step and the second fixing step, a backing plate is placed on the side of the fixing location of the extruded panel opposite to the base plate. A method for manufacturing a structural member according to claim 3.

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