Joined body and method for manufacturing joined body

Abstract

To provide a joined body excellent in both joining strength and rigidity by preventing the deterioration of welding quality caused by the interposition of an adhesive.SOLUTION: The joined body 1 has a weld zone 4 and an adhesive layer 5 between at least two metal sheets 2, 3 overlapping each other. A projecting part 6 is provided in a part positioned between the welding part 4 and the adhesive layer 5 in one metal plate 2, and a recessed part 7 fitted to the projecting part 6 is provided in a position opposed to the projecting part 6 of the other metal plate 3.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a joined body and a method for manufacturing the joined body, and more particularly to a manufacturing technique for a joined body in which a weld and an adhesive layer are provided between at least two overlapping metal plates. [Background technology]

[0002] Conventionally, in the manufacturing process of automobiles, multiple metal plates are integrated by spot welding. This type of welding is usually performed by sandwiching two or more metal plates to be welded between a pair of welding electrodes, applying pressure, and passing an electric current under predetermined conditions (see, for example, Patent Document 1).

[0003] On the other hand, recently, a method of joining multiple metal plates by combining spot welding and adhesive bonding has been proposed and implemented with the aim of improving not only the joint strength but also the rigidity of the joined body. For example, Patent Document 2 describes a method of obtaining a joined body in which spot welds and planar adhesive joints coexist, by sandwiching an adhesive between a pair of plates to be spot welded and applying electricity to the portions of the pair of plates where the adhesive is sandwiched between them. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-55338 [Patent Document 2] Japanese Patent Application Publication No. 2023-149228 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when attempting to form point-like welds in the bonding area by spot welding as described above, the adhesive flows due to heat softening caused by pressure or current flow, which can cause unstable contact between the metal plates, leading to the generation of dust (sparks) and blowholes, and can also lead to deterioration of the welding quality.Furthermore, the adhesive can scatter into the surrounding area, which can lead to a deterioration of the manufacturing environment.

[0006] To avoid the above-mentioned problems, a method of applying adhesive intermittently and spot welding the non-applied areas can be considered. However, if the amount of adhesive applied varies and more adhesive is applied near the weld, or if the metal plates are stacked out of position, the adhesive that was previously applied to one of the metal plates may be squeezed out and flow into the planned welding area when the metal plates are stacked. This makes it difficult to solve the above-mentioned problems.

[0007] In view of the above circumstances, the technical problem to be solved in this specification is to prevent deterioration in welding quality due to the presence of an adhesive and to provide a joined body that is excellent in both joining strength and rigidity. [Means for solving the problem]

[0008] The above-mentioned problems are solved by a joined body according to the present invention, which is a joined body having a weld and an adhesive layer formed between at least two overlapping metal plates, characterized in that one of the metal plates has a convex portion located between the weld and the adhesive layer, and the other metal plate has a concave portion located opposite the convex portion and fitting into the convex portion.

[0009] Thus, in the bonded structure according to the present invention, a weld and an adhesive layer are provided between at least two metal plates. Therefore, a convex portion is provided on one of the overlapping metal plates in a portion located between the weld and the adhesive layer. When the metal plates are overlapped, the convex portion blocks the adhesive extruded from the previously supplied area, thereby preventing the adhesive from flowing into the area where the weld is to be formed (the area to be welded). Furthermore, by providing a concave portion that fits into the convex portion on the other metal plate in a position facing the convex portion, the convex portion and the concave portion form a narrow space between the adhesive supply area and the area to be welded. By providing a space around the area to be welded that is difficult for the adhesive to penetrate, it is possible to more effectively prevent the adhesive from flowing into the area to be welded.

[0010] Furthermore, by providing a recessed portion that fits into the protruding portion, when the two metal plates are overlapped, it is possible to prevent the region of the other metal plate other than the recessed portion, particularly the region to be welded, from being tilted or deformed by being pressed by the protruding portion. Therefore, it is possible to avoid the electrode from excessively digging into or contacting the other metal plate unevenly during pressure and current application, making it possible to obtain a high-quality weld. Furthermore, when welding overlapping flat metal plates without adhesive, welding can be performed using the optimal pressure and current application conditions as in the past, making it possible to consistently obtain high-quality welds.

[0011] In the bonded body according to the present invention, the convex portion may surround the periphery of the welded portion.

[0012] The provision of such a convex portion makes it possible to more effectively prevent the adhesive from flowing into the intended welding area, and therefore makes it possible to stably obtain a bonded body having both a high-quality weld and an adhesive layer without strictly controlling, for example, the amount of adhesive supplied or the area where it is supplied.

[0013] In the bonded structure according to the present invention, the convex portion and the concave portion may be in contact with each other.

[0014] As described above, the convex portion and the concave portion are positioned to fit together, so that the contact between the convex portion and the concave portion closes at least a portion of the narrow space formed between the convex portion and the concave portion, thereby more likely preventing the adhesive from flowing into the intended welding area through the narrow space.

[0015] The above-mentioned problem is also solved by a method for manufacturing a joined body according to the present invention. That is, this manufacturing method is a method for manufacturing a joined body in which a weld and an adhesive layer are formed between at least two overlapping metal plates, and includes an adhesive supplying step of supplying an adhesive to form the adhesive layer to one metal plate, and a welding step of overlapping the one metal plate to which the adhesive has been supplied and the other metal plate and welding the overlapping portion to form a weld, characterized in that the welding step uses one metal plate having a convex portion provided between the portion where the weld is to be formed and the area to which the adhesive is supplied, and the other metal plate having a concave portion provided in a position facing the convex portion and fitting into the convex portion.

[0016] According to the method for manufacturing a joined body of the present invention, as with the joined body of the present invention, a convex portion is provided between the portion of one of the overlapping metal plates where the weld is formed and the region where the adhesive layer is supplied. Therefore, when the metal plates are overlapped, the convex portion blocks the adhesive extruded from the supply region, thereby preventing the adhesive from flowing into the portion where the weld is formed (the planned welding region). Furthermore, by providing a concave portion that fits into the convex portion on the other metal plate at a position facing the convex portion, the convex portion and the concave portion can form a narrow space between the adhesive supply region and the planned welding region. By providing a space around the planned welding region that is difficult for the adhesive to penetrate, it is possible to more effectively prevent the adhesive from flowing into the planned welding region.

[0017] Furthermore, by providing a recessed portion that fits into the protruding portion, when the two metal plates are overlapped, it is possible to prevent the region of the other metal plate other than the recessed portion, particularly the region to be welded, from being tilted or deformed by being pressed by the protruding portion. Therefore, it is possible to avoid the electrode from excessively digging into or contacting the other metal plate unevenly during pressure and current application, making it possible to obtain a high-quality weld. Furthermore, when welding overlapping flat metal plates without adhesive, welding can be performed using the optimal pressure and current application conditions as in the past, making it possible to consistently obtain high-quality welds. [Effects of the Invention]

[0018] As described above, according to the joined body or the method for manufacturing the joined body of the present invention, it is possible to prevent deterioration of welding quality due to the presence of an adhesive and to provide a joined body having excellent joint strength and rigidity. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 2 is a plan view of a main part of a bonded body according to an embodiment of the present invention. [Figure 2] 2 is a cross-sectional view of the bonded body shown in FIG. 1 along the line AA. [Figure 3] 2 is a flowchart showing a flow of a method for manufacturing the bonded body shown in FIG. [Figure 4] 4A is a plan view of a main part of one metal plate and FIG. 4B is a plan view of a main part of the other metal plate that are supplied to the bonding preparation step shown in FIG. 3. [Figure 5] 4A is a plan view of a main part of one of the metal plates in a state where an adhesive is applied in the bonding preparation step shown in FIG. 3, and FIG. 4B is a side view seen from the direction of arrow B. FIG. [Figure 6] 4 is a cross-sectional view showing a state in which two metal plates are overlapped in the welding step shown in FIG. 3. FIG. [Figure 7] 4 is a cross-sectional view showing a state immediately after application of pressure and current by a pair of welding electrodes is started in the welding step shown in FIG. 3. FIG. [Figure 8] FIG. 10 is a plan view of a main part of a bonded body according to another embodiment of the present invention. [Figure 9] FIG. 10 is a cross-sectional view of a bonded body according to still another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, a bonded body and a method for manufacturing the bonded body according to one embodiment of the present invention will be described with reference to the drawings. First, the bonded body according to this embodiment will be described, and then the method for manufacturing the bonded body will be described.

[0021] Fig. 1 shows a plan view of a main portion of a joined body 1 according to one embodiment of the present invention. Fig. 2 shows a cross-sectional view taken along line AA of the joined body 1 shown in Fig. 1. As shown in Figs. 1 and 2, the joined body 1 has a welded portion 4 and an adhesive layer 5 between two overlapping metal plates 2 and 3, and the two metal plates 2 and 3 are fixed together and integrated by the welded portion 4 and the adhesive layer 5.

[0022] In this embodiment, as shown in Figure 1, adhesive layers 5 are provided intermittently along the edges 2a, 3a of each metal plate 2, 3, and welds 4 are provided in areas near the edges 2a, 3a where no adhesive layer 5 is provided, in this case the areas between the adhesive layers 5, 5.

[0023] Furthermore, a convex portion 6 is provided between the weld 4 and the adhesive layer 5, protruding from one metal plate 2 toward the other metal plate 3 (see FIG. 2). Furthermore, a concave portion 7 that fits into the convex portion 6 is provided on the other metal plate 3 at a position facing the convex portion 6 (see FIG. 2 for both). These convex portion 6 and concave portion 7 are provided to prevent the adhesive that will become the adhesive layer 5 adjacent to one side from flowing into the portion where the weld 4 adjacent to the other side is to be formed when the weld 4 is formed. Detailed effects will be described later.

[0024] The convex portion 6 has, for example, a ridge shape and extends in a predetermined manner. In this embodiment, the convex portion 6 extends in a U-shape so as to surround the welded portion 4. Furthermore, in this embodiment, one end and the other end in the longitudinal direction of the convex portion 6 extend to the side end surface 2a1 of the edge portion 2a, completely separating the region 2b1 on the surface 2b of one metal plate 2 where the welded portion 4 is located from the region 2b2 on the side where the adhesive layer 5 is located. In this case, the concave portion 7 has a shape corresponding to the convex portion 6. That is, the concave portion 7 extends in a U-shape so as to surround the welded portion 4, and one end and the other end in the longitudinal direction of the concave portion 7 extend to the side end surface 3a1 of the edge portion 3a of the other metal plate 3, so as to fit over the entire area of ​​the convex portion 6.

[0025] In this embodiment, at least a portion of the convex portion 6 is in contact with the concave portion 7. In the example shown in Fig. 2, the inner side of the convex portion 6 (the side closer to the welded portion 4) is in contact with the inner side of the concave portion 7 (the side closer to the welded portion 4) over the entire longitudinal area.

[0026] Next, an example of a method for manufacturing the bonded body 1 having the above-mentioned configuration will be described, and the effects of the present invention will be described in the description.

[0027] Fig. 3 is a flowchart showing the flow of a manufacturing method for a joined body 1 according to one embodiment of the present invention. As shown in Fig. 3, the manufacturing method for the joined body 1 includes an adhesion preparation step S1 in which an adhesive 5a is supplied to one metal plate 2 of two metal plates 2 and 3 to be joined to prepare for adhesion, a welding step S2 in which the two metal plates 2 and 3 are overlapped and welded, and a bonding step S3 in which the adhesive 5a supplied to one metal plate 2 is solidified to bond and fix the two metal plates 2 and 3.

[0028] (S1) Adhesion preparation process In this step S1, two metal plates 2, 3 to be joined are prepared, and an adhesive 5a to become an adhesive layer 5 is supplied to one of the two prepared metal plates 2, 3, the metal plate 2 having the convex portion 6 provided thereon.

[0029] First, as shown in FIG. 4(a), one metal plate 2 having a convex portion 6 is prepared. Here, the shape of the convex portion 6 is as described in the description of the configuration of the joined body 1. In terms of the state before joining, this convex portion 6 is provided between the portion of the joining side surface 2b of one metal plate 2 where the weld 4 is to be formed (region to be welded 2c1) and the region 2c2 to which the adhesive 5a is to be supplied. In this case, the region to be welded 2c1 is included in the region 2b1 on the side where the weld 4 is located, and the region 2c2 to which the adhesive 5a is to be supplied is included in the region 2b2 on the side where the adhesive layer 5 is located.

[0030] Additionally, in this step S1, the other metal plate 3 having a recess 7 formed therein is prepared as shown in Fig. 4(b). The shape of the recess 7 is as described in the description of the configuration of the bonded body 1.

[0031] After preparing the two metal plates 2, 3 described above, adhesive 5a is supplied to one of the metal plates 2. Specifically, as shown in FIG. 5, a predetermined adhesive 5a is supplied to a predetermined region (adhesive supply region 2c2) on the joining side surface 2b of one of the metal plates 2, near the edge 2a and along the edge 2a. In this embodiment, the adhesive 5a is supplied so that welds 4 and adhesive layers 5 are alternately formed along the edge 2a. Here, there is no particular restriction on the type of adhesive 5a, and any adhesive with excellent mechanical properties, such as a structural adhesive, can be used without any particular restrictions.

[0032] In principle, the adhesive 5a can be applied in any manner, for example, by a sealer gun. In this case, it is preferable to apply the adhesive 5a intermittently along the edge 2a while avoiding the planned welding area 2c1, or more precisely, avoiding the planned welding area 2c1 and the convex portion 6. This allows the adhesive 5a to be supplied up to a position adjacent to the convex portion 6. In this case, the application height of the adhesive 5a or the height dimension of the convex portion 6 is preferably set so that the height of the adhesive 5a is lower than that of the convex portion 6 (see FIG. 5(b)).

[0033] (S2) Welding process In this step S2, the two metal plates 2 and 3 prepared in the bonding preparation step S1 are first overlapped. At this time, the two metal plates 2 and 3 are overlapped at a predetermined position so that the convex portion 6 of one metal plate 2 and the concave portion 7 of the other metal plate 3 fit together (see FIG. 6). This allows the two metal plates 2 and 3 to be automatically aligned in the planar direction. Depending on the manner in which the adhesive 5a is supplied, it is conceivable that the adhesive 5a supplied to one metal plate 2 may be crushed and flow toward the planned welding region 2c1 when the two metal plates are overlapped. However, because the convex portion 6 is provided between the adhesive supply region 2c2 and the planned welding region 2c1 (see FIG. 4(a)), even if the crushed adhesive 5a flows toward the planned welding region 2c1, the adhesive 5a is blocked by the convex portion 6 (see FIG. 6). Therefore, when the metal plates 2 and 3 are placed on top of each other, it is possible to prevent as much as possible the adhesive 5a from flowing into the intended welding region 2c1.

[0034] After the metal plates 2, 3 are overlapped as described above, the welding area 2c1 is clamped between a pair of welding electrodes 8, 8, and pressure and current application is initiated under predetermined conditions (see FIG. 7 ). This heats the welding area 2c1 of one metal plate 2 and the overlapping portion of this welding area 2c1 and the other metal plate 3, forming a weld 4 as shown in FIG.

[0035] It is anticipated that when applying pressure and current, the gap 9 in the planned welding region 2c1 between the two metal plates 2, 3 will close, further squeezing the adhesive 5a supplied to the adhesive supply region 2c2, but the narrow space 10 formed between the mating convex portion 6 and concave portion 7 prevents the adhesive 5a from entering this narrow space 10. This makes it possible to more effectively prevent the adhesive 5a from flowing into the planned welding region 2c1.

[0036] (S3) Adhesion process After forming the welded portion 4 as described above, the adhesive 5a is solidified (cured) by a corresponding means to form an adhesive layer 5 as shown in Fig. 1 between the two metal plates 2, 3. Since the two metal plates 2, 3 are sandwiched together during welding, the adhesive 5a is in close contact with both metal plates 2, 3, and so by solidifying the adhesive 5a in this step S3, the two metal plates 2, 3 are bonded and fixed to each other via the adhesive layer 5. The joined body 1 is manufactured through the above steps S1 to S3.

[0037] As described above, in the joined body 1 and the method for manufacturing the joined body 1 according to the present embodiment, the convex portion 6 is provided between the portion of one metal plate 2 of the two overlapping metal plates 2, 3 where the weld 4 is to be formed (the planned welding region 2c1) and the region where the adhesive layer 5 is to be formed (the adhesive supply region 2c2). Therefore, when the metal plates 2, 3 are overlapped, the convex portion 6 blocks the adhesive 5a extruded from the adhesive supply region 2c2, thereby minimizing the possibility of the adhesive 5a flowing into the planned welding region 2c1. Furthermore, by providing the other metal plate 3 with a recessed portion 7 that fits into the convex portion 6 at a position facing the convex portion 6, the convex portion 6 and the recessed portion 7 form a narrow space 10 between the adhesive supply region 2c2 and the planned welding region 2c1. By providing a space (narrow space 10) around the planned welding region 2c1 that is difficult for the adhesive 5a to penetrate, it is possible to more effectively prevent the adhesive 5a from flowing into the planned welding region 2c1.

[0038] Furthermore, by providing the recessed portion 7 that fits into the protruding portion 6, when the two metal plates 2, 3 are overlapped, it is possible to prevent the region of the other metal plate 3 other than the recessed portion 7, particularly the to-be-welded region 2c1, from being tilted or deformed by being pressed by the protruding portion 6. This prevents the electrode 8 from excessively digging into or contacting the other metal plate 3 on one side during pressure and current application, making it possible to obtain a high-quality welded joint 4. Furthermore, when welding overlapping portions of flat metal plates 2, 3 without the adhesive 5a interposed therebetween, it is possible to apply the optimum pressure and current application conditions as in the past, making it possible to stably obtain a high-quality welded joint 4.

[0039] In addition, in this embodiment, the convex portion 6 is provided so as to surround the periphery of the welded portion 4 in the state of the joined body 1 (see FIG. 1), which makes it possible to more likely prevent the adhesive 5a from flowing into the intended welding region 2c1 during the welding step S2. Therefore, it is possible to stably obtain the joined body 1 having both the high-quality welded portion 4 and the adhesive layer 5, for example, without strictly controlling the supply amount and supply area of ​​the adhesive 5a.

[0040] Furthermore, in this embodiment, the convex portions 6 are formed so that they are in contact with the concave portions 7 when the two metal plates 2, 3 are overlapped. The convex portions 6 and the concave portions 7 are positioned to fit together, and therefore the contact of the convex portions 6 with the concave portions 7 closes at least a portion of the narrow space 10 formed between the convex portions 6 and the concave portions 7 (see FIG. 2). This makes it possible to more effectively prevent the adhesive 5a from flowing into the intended welding region 2c1 through the narrow space 10.

[0041] Although one embodiment of the present invention has been described above, the bonded body and the method for manufacturing the bonded body according to the present invention can also adopt configurations other than those described above within the scope of the spirit thereof.

[0042] For example, in the above embodiment, the convex portion 6 is formed to surround the planned welding region 2c1. However, the shape of the convex portion 6 is not particularly limited as long as at least a portion of the convex portion 6 is located between the welding portion 4 (planned welding region 2c1) and the adhesive layer 5 (adhesive supply region 2c2). For example, although not shown, a convex portion having an annular shape in plan view may be provided on one of the metal plates 2 so as to surround the entire circumference of the welding portion 4 (planned welding region 2c1). Alternatively, the convex portion may be provided within the minimum necessary range to prevent the adhesive 5a from flowing into the planned welding region 2c1. FIG. 8 shows a plan view of a main portion of a joined body 11 according to one example (another embodiment of the present invention). As shown in FIG. 8, in the joined body 11 according to this embodiment, one of the metal plates 12 is provided with a convex portion 16 that extends linearly and intersects (orthogonally in the illustrated example) the direction along the edge 2a of the one of the metal plates 12. Similarly to the convex portion 16 of the above embodiment, the other metal plate 13 is provided with a concave portion 17 that extends linearly and fits into the convex portion 16 when the two metal plates 12, 13 are overlapped. This configuration makes it possible to easily create both the convex portion 16 and the concave portion 17 in a simple shape, while also effectively preventing the adhesive 5a from flowing into the intended welding region 2c1.

[0043] In all of the embodiments, the case where one end of the convex portion 6, 16 extends to the side end surface 2a1 of the edge portion 2a of one of the metal plates 2, 12 has been exemplified, but of course, this is not limited to this. Depending on the application area and amount of adhesive 5a, the convex portion 6, 16 may be formed so that one end is located closer to the center than the side end surface 2a1.

[0044] Furthermore, in this embodiment, the convex portions 6, 16 protrude from one of the front surfaces 2b of the metal plates 2, 12 and have a flat back surface. However, other configurations are also possible. FIG. 9 shows a cross-sectional view of a bonded assembly 21 according to one example (another embodiment of the present invention). As shown in FIG. 9, in the bonded assembly 21 according to this embodiment, the convex portion 26 provided on the one metal plate 22 protrudes toward the other metal plate 23 and has a recess 26a on the back surface. In this case, the other metal plate 23 is provided with a recess 27 that fits into the convex portion 26 at a position facing the convex portion 26. If the one metal plate 22 has a convex portion 26 of this configuration, the convex portion 26 can be formed simultaneously with three-dimensional shaping of the one metal plate 22 by, for example, press working, which is advantageous from a cost perspective. Of course, the method for forming the convex portions 6, 16, 26 is not limited to press working. A part of one of the metal plates 2, 12, 22 may be formed into the convex portion 6, 16, 26 by various machining processes such as cutting. Alternatively, only the protruding portion of the convex portion 6, 16 may be formed separately from the main body of one of the metal plates 2, 12 and then integrated with the main body.

[0045] Furthermore, in this embodiment, an example is given of supplying adhesive 5a to the metal plate on the side where convex portion 6 is provided (one metal plate 2), but it goes without saying that adhesive 5a may also be supplied to the metal plate on the side where concave portion 7 is provided (the other metal plate 3).

[0046] Furthermore, in the above explanation, an example has been given of the application of the present invention to a joined body 1 in which a weld 4 and an adhesive layer 5 are provided between two metal plates 2, 3, and a manufacturing method thereof, but it is of course possible to apply the present invention to joined bodies having other structures. For example, although not shown, it is also possible to apply the present invention to a joined body in which a weld 4 is formed across a set of three metal plates and an adhesive layer is formed between any one pair (two) of adjacent metal plates. Of course, it is also possible to apply the present invention to a joined body in which an adhesive layer is provided between each of two pairs of adjacent metal plates of a set of three metal plates. [Explanation of symbols]

[0047] 1,11,21 zygote 2,12,22 One metal plate 2a Edge 2a1 Side end face 2b surface 2b1 Area on the side where the weld is located 2b2 Area where the adhesive layer belongs 2c1 Planned welding area 2c2 Adhesive supply area 3, 13, 23 The other metal plate 3a Edge 3a1 Side end face 4 Welded parts 5 Adhesive layer 5a Adhesive 6,16,26 Convex part 7,17,27 Concave part 8 Welding electrodes 9 Gap 10. Small Space 26a Recess S1 Adhesion preparation process S2 Welding process S3 Adhesion process

Claims

1. A joint in which a weld and an adhesive layer are formed between at least two overlapping metal plates, A joint body, in which a convex portion is provided in a portion of one of the metal plates located between the welded portion and the adhesive layer, and a concave portion that fits into the convex portion is provided in a position facing the convex portion of the other metal plate.

2. A method for manufacturing a joint in which a weld and an adhesive layer are formed between at least two overlapping metal plates, comprising: an adhesive supplying step of supplying an adhesive to one of the metal plates to form the adhesive layer; a welding step of overlapping the one metal plate to which the adhesive has been supplied and the other metal plate, and performing the welding on the overlapping portion to form the welded portion, A method for manufacturing a joined body, wherein the welding process uses one metal plate having a convex portion provided between the part where the weld is formed and the area where the adhesive is supplied, and the other metal plate having a concave portion provided at a position opposite the convex portion that fits into the convex portion.

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