Joint structure

Abstract

A joint structure 1 includes: a first member 10; a second member 20 arranged opposite to the first member 10; a joint part 50 for joining the first member 10 and the second member 20 by adhesion; and a suppression part 22. The suppression part 22 is arranged in a target area A10 including a joint area A11 where the joint part 50 is arranged and a peripheral area A12 which is a periphery of the joint area A11, and suppresses approach of the first member 10 and the second member 20. The suppression part 22 protrudes from the second member 20 to the first member 10 side. The joint part 50 has a constricted part 51 partway through a direction Z in which the first member 10 and the second member 20 face each other. The smallest outer diameter D51 of the constricted part 50 is larger than the outer diameter D22 of a tip of the suppression part 22.

Description

Joint structure

[0001] The present disclosure relates to a joint structure using an adhesive.

[0002] Some exterior parts of automobiles are made up of thin panels. For example, a panel such as an outer panel of an automobile hood is joined to an inner member with an adhesive such as a mastic sealer at a position that maintains a certain clearance between the inner member and the panel (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2023-147940

[0004] Usually, when the outer panel and the inner member are joined with an adhesive, the adhesive has not yet hardened, and the outer panel and the inner member are in a state where they can easily move relative to each other. In this state, the outer panel may be washed with a powerful shower. At this time, the outer panel is subjected to a strong external force from the shower water.

[0005] Here, if the outer panel is thick, its rigidity is high, so even if a strong external force acts on the outer panel, the amount of deflection and displacement at the adhesive-applied portion of the outer panel is small. However, panels are required to be further lightened to improve energy-saving performance. To reduce the weight of automobile bodies, when the thickness of outer panels of automobile bodies such as hoods, doors, and roofs is reduced to less than 0.6 mm, the outer panel becomes particularly prone to deflection. Therefore, when a thin outer panel is subjected to an external force such as a high-pressure shower, if the adhesive is relatively soft before curing, the external force temporarily narrows the clearance between the outer panel and the inner member. As a result, the adhesive between the outer panel and the inner member is severely crushed. If the adhesive is severely crushed, even if the external force is removed and the clearance between the outer panel and the inner member returns to normal, the adhesive may become deficient. Such a deficient state is undesirable for ensuring the adhesive bond strength between the outer panel and the inner member.

[0006] In view of the above problems, the present disclosure aims to suppress deficiencies in joints formed with adhesive in joint structures for automobile panels and the like, thereby enabling the original joint performance to be exhibited.

[0007] The present disclosure relates to the following joining structure.

[0008] (1) A joining structure comprising: a first member; a second member arranged opposite the first member; and a joining portion that joins the first member and the second member by adhesive, the joining structure comprising: a suppression portion that suppresses the first member and the second member from approaching each other in a target area including a joining area where the joining portion is arranged and a peripheral area around the joining area; the suppression portion protruding from the second member toward the first member; the joining portion having a constricted portion midway in the direction in which the first member and the second member face each other; and the minimum outer diameter of the constricted portion being larger than the outer diameter of the tip of the suppression portion.

[0009] (2) The joint structure according to (1), wherein the suppression portion is provided in a part of the target area.

[0010] (3) The joining structure described in (1) or (2), wherein the second member includes a flat portion, and the suppression portion protrudes from the flat portion toward the first member in the target region.

[0011] (4) The second member includes a flat portion and a convex base protruding from the flat portion toward the first member in the target area, and the suppression portion protrudes from the convex base toward the first member, in the joining structure described in (1) or (2).

[0012] (5) The second member includes a flat portion and a recessed base recessed from the flat portion in the target area, and the suppression portion protrudes from the second member toward the first member in the target area, in the joining structure described in (1) or (2).

[0013] (6) The joint structure according to any one of (1) to (5), wherein the joint portion covers the entire suppression portion.

[0014] (7) A joint structure according to any one of (1) to (6), wherein the outer diameter of the suppression portion is half or less of the outer diameter of the joint portion.

[0015] (8) The joint structure according to any one of (1) to (7), wherein a plurality of the joints are arranged side by side.

[0016] (9) The joint structure according to (8), wherein the plurality of joints are arranged in a ring shape.

[0017] (10) A joining structure according to any one of (1) to (9), wherein the outer peripheral surface of the joining portion is spaced apart from the first member and the second member.

[0018] (11) The joining structure described in any one of (1) to (10), wherein the first member is an outer panel of an automobile, the second member is an inner member joined to the outer panel by the joining portion, and the suppression portion is provided on the inner member.

[0019] According to the present disclosure, in a joining structure for automobile panels or the like, it is possible to suppress deficiencies in the joint formed with adhesive and to exhibit the original joining performance.

[0020] FIG. 1 is a schematic cross-sectional view showing a joint structure according to an embodiment of the present disclosure. FIGS. 2A to 2C are diagrams showing an example of a manufacturing method of a joint structure. FIG. 3 is a cross-sectional view of a main portion of Modification 1. FIG. 4 is a cross-sectional view of a main portion of Modification 2, with FIG. 4A showing the completed joint structure and FIG. 4B showing the joint structure in the middle of its manufacturing. FIG. 5 is a cross-sectional view of a main portion of Modification 3, with FIG. 5A showing the completed joint structure and FIG. 5B showing the joint structure in the middle of its manufacturing. FIG. 6A is a plan view of a main portion of Modification 4 showing a configuration in which a plurality of joints are arranged side by side, and FIG. 6B is a schematic vertical cross-sectional view of the configuration shown in FIG. 6A.

[0021] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In this embodiment, a joining structure 1 for an outer panel of an automobile will be described as an example of a joining structure. Examples of outer panel panels of an automobile include an outer panel of an automobile hood, an outer door panel, a roof panel, a fender panel, and a back door panel. The present disclosure may also be applied to joining structures other than automobiles.

[0022] Fig. 1 is a schematic cross-sectional view showing a joint structure 1 according to an embodiment of the present disclosure. Figs. 2A to 2C are diagrams showing an example of a manufacturing method of the joint structure 1. As shown in Fig. 1, the joint structure 1 is provided, for example, on an automobile front hood or the like provided at the front of an automobile.

[0023] The joining structure 1 includes a first member 10 located on the outside of the vehicle, a second member 20 as an inner member located opposite the first member 10 on the inside of the vehicle, and a joining portion 50 which is an adhesive that joins the first member 10 and the second member 20. The joining structure 1 has a target area A10 formed between the first member 10 and the second member 20, the target area A10 including a joining area A11 where the joining portion 50 is located and a peripheral area A12 that is the periphery of the joining area A11.

[0024] The first member 10 is, for example, a plate-shaped outer panel. The second member 20 is, for example, an inner panel, and may be a reinforcement member that supports a roof panel, a framework reinforcement member that is joined to a door outer panel, or the like.

[0025] The first member 10 constitutes a part of the exterior surface of the automobile. The first member 10 is formed of a metal material such as a mild steel plate or a high-tensile steel plate. Examples of high-tensile steel plates include steel plates with a tensile strength of 340 MPa or more, such as a steel plate with a tensile strength of 590 MPa or more. The tensile strength can be measured, for example, by taking a flat portion 21 (a portion with a curvature radius of 1000 mm or more) of the first member 10 as a test specimen and measuring it according to JIS (Japanese Industrial Standards) Z2241 (2011). The first member 10 is formed, for example, by press-forming a steel plate. The thickness of the first member 10 (the thickness of the steel plate) is set to 0.60 mm or less, preferably 0.50 mm or less, and more preferably 0.40 mm or less. The thickness of the first member 10 is, for example, 0.30 to 0.45 mm. As such, the thinner the thickness of the first member 10, the lighter the joining structure 1 can be.

[0026] When the first member 10 is made of an aluminum alloy, the plate thickness of the first member 10 is, for example, 0.50 to 0.80 mm.

[0027] There are no particular restrictions on the shape of the first member 10. The first member 10 is formed relatively flat, and the radius of curvature is several thousand mm or more, excluding portions with large changes in curvature such as character lines. The outer peripheral edge of the first member 10 is joined to the outer peripheral edge of the second member 20 by, for example, hemming. Figure 1 shows central portions of the first member 10 and the second member 20, and does not show the joined portions formed by hemming or the like.

[0028] The second member 20 reinforces the first member 10 by being joined to the first member 10 via a joint 50. As a result, the second member 20 increases the surface rigidity, such as the tensile rigidity, of the first member 10.

[0029] The tension stiffness corresponds to the sense of elastic resistance or deflection when the first member 10 is pressed by hand. This characteristic is usually expressed as the amount of deflection when a load is applied, and the smaller the amount of deflection when a certain load is applied, the higher the tension stiffness. Furthermore, the surface stiffness refers to the resistance to deformation within a certain area range of the outer panel when the first member 10 receives a load such as a vertical load from the outer surface of the first member 10.

[0030] The second member 20 is formed by, for example, pressing a metal material such as a steel plate. The thickness of the second member 20 (the thickness of the steel plate) is preferably 0.30 mm to 0.60 mm. The thickness of the second member 20 may be less than the thickness of the first member 10, may be the same as the thickness of the first member 10, or may be greater than the thickness of the first member 10.

[0031] When the second member 20 is made of an aluminum alloy, the thickness of the second member 20 is, for example, 0.50 to 1.00 mm, and may be 0.50 to 0.80 mm. In this embodiment, the direction in which the first member 10 and the second member 20 face each other, i.e., the thickness direction of the first member 10 and the second member 20, is referred to as the thickness direction Z, and viewing in the thickness direction Z is simply referred to as viewing in the thickness direction.

[0032] The second member 20 includes a flat portion 21 and a suppression portion 22 that protrudes from the flat portion 21 toward the first member 10 in the target area A10.

[0033] The flat portion 21 is a flat portion having approximately the same radius of curvature as a portion of the first member 10 facing it in the plate thickness direction Z. The flat portion 21 is not limited to being completely flat (having an infinite radius of curvature), and may be a portion having a radius of curvature of several hundred mm or more, 1,000 mm or more, several thousand mm or more, or 10,000 mm or more.

[0034] A seating surface 23 that comes into contact with the joint 50 is set on the upper surface of the flat portion 21 in the target area A10. The seating surface 23 is generally parallel to a portion of the underside 10a of the first member 10 that faces the seating surface 23 in the plate thickness direction Z. The seating surface 23 may be inclined with respect to the portion of the underside 10a of the first member 10 that faces the seating surface 23 in the plate thickness direction Z. A suppressing portion 22 is formed on the seating surface 23.

[0035] The suppression unit 22 is installed in a portion of the target area A10 and is configured to suppress approach between the first member 10 and the second member 20 along the plate thickness direction Z. The region of the target area A10 where the joint 50 is actually located is the joining area A11. The peripheral area A12 is a region surrounding the joining area A11, and can also be said to be a region within a distance of, for example, several tens of millimeters to several hundred millimeters from the joint 50 in a direction perpendicular to the plate thickness direction Z of the first member 10. In this embodiment, the joining area A11 is located between the bearing surface 23 and a portion of the underside 10a of the first member 10 that faces the bearing surface 23 in the plate thickness direction Z. In this embodiment, a portion of the bearing surface 23 and the suppression unit 22 are located in the joining area A11.

[0036] The suppression portion 22 is formed in a protruding shape that protrudes from the seating surface 23 toward the first member 10, and can be considered an embossed protrusion. The shape of the suppression portion 22 is not limited to a specific shape, as long as it is formed in a shape that protrudes from the seating surface 23 toward the first member 10. The suppression portion 22 is formed by, for example, press processing the material that will become the second member 20, and is not configured by providing a through-portion such as a slit in the material and deforming the periphery of the through-portion so that the periphery of the through-portion is raised. In other words, no portion formed by penetrating the second member 20 exists around the suppression portion 22 throughout the entire circumferential direction of the suppression portion 22. The suppression portion 22 may be formed in a truncated cone shape or a truncated polygonal pyramid shape. It is preferable that the tip of the suppression portion 22 is not sharp. This is because, when the first member 10 and the second member 20 are brought closer to each other, deformation due to stress concentration is likely to occur in the first member 10 due to the sharpness of the suppression portion 22. That is, it is preferable that the tip of the suppression portion 22 is flat. The tip of the suppression portion 22 is formed, for example, by a tip surface 22a, which may be flat or curved, and is preferably flat. If the tip surface 22a is a curved surface that is convex toward the first member 10, the outer diameter D22 of the tip surface 22a is measured at a point where the outer peripheral surface 22b changes from a straight line to a curve (a point where the radius of curvature changes) when moving from the portion of the suppression portion 22 that is continuous with the seat surface 23 toward the first member 10 in the cross section shown in FIG. 1 .

[0037] The suppression portion 22 preferably has a tapered shape toward the first member 10. With this configuration, when the first member 10 and the second member 20 approach each other while the adhesive 40 is in a state before the joint 50 hardens, the load within the joint 50 can be smoothly distributed. In a cross section perpendicular to the thickness direction Z, the suppression portion 22 preferably has a circular shape, which allows for smooth distribution of the load within the joint 50. The height of the suppression portion 22 from the seating surface 23 is set to, for example, several millimeters. In a free state in which no external force is acting between the first member 10 and the second member 20 in a direction that causes them to approach each other in the thickness direction Z, the suppression portion 22 is spaced apart from the first member 10 in the thickness direction Z. In the free state, the distance D1 between the suppression portion 22 and the first member 10 in the thickness direction Z is less than the distance D2 (the height of the joint 50) between the seating surface 23 of the second member 20 and the first member 10 in the joint region A11.

[0038] The joint 50 is an adhesive. An example of this adhesive is a mastic sealer (mastic adhesive). An example of this mastic sealer is a resin-based adhesive. The adhesive may have a property of hardening at room temperature (e.g., 20 degrees Celsius), or may have a property of hardening after undergoing a heating process or a drying process. The joint 50 is a curing adhesive that hardens after being applied to the first member 10 and the second member 20.

[0039] The joint 50 joins the seating surface 23 on which the joint 50 is provided and the underside 10a of the first member 10. The specific shape of the joint 50 is not limited as long as the joint 50 joins the first member 10 and the second member 20. The joint 50 preferably covers the entire suppression portion 22, but may also cover a portion of the suppression portion 22. In this embodiment, the joint 50 is bonded to the outer peripheral surface 22b of the suppression portion 22 and to an annular base end portion that is continuous with the seating surface 23.

[0040] The joint 50 has a constricted portion 51 midway in the thickness direction Z (the direction in which the first member 10 and the second member 20 face each other). As shown in FIG. 1 , the constricted portion 51 may be formed near the middle of the joint 50 in the thickness direction Z. As will be described later with reference to FIG. 2 , the constricted portion 51 is formed when a load F, such as high-pressure shower water for cleaning, acts on the first member 10 while the adhesive 40 is in a state before the joint 50 hardens, temporarily reducing the clearance C between the first member 10 and the second member 20. The diameter of the constricted portion 51 may or may not be the minimum diameter at the joint 50. In some cases, the diameter of the joint 50 at the lower surface 10 a of the first member 10 is larger than the diameter at the bearing surface 23. 2A , the adhesive 40 that will become the joint 50 is applied to the suppression portion 22, and then, when the clearance C between the first member 10 and the second member 20 becomes small before the adhesive 40 hardens to become the joint 50, the adhesive 40 passes over the suppression portion 22 and reaches the seating surface 23. The outer diameter D50, which is the maximum diameter of the joint 50, is approximately 5 mm to 25 mm, and an example of this is 10 mm. The outer diameter D22 of the tip surface 22a (tip) of the suppression portion 22 is approximately 5 mm to 15 mm, and an example of this is 5 mm or 10 mm.

[0041] As shown in FIG. 1 , the outer diameter D22 of the tip surface 22a, which is the tip of the suppression portion 22, may be less than half the outer diameter D50 of the joint portion 50. In this case, the outer diameter D50 of the joint portion 50 is the maximum diameter of the joint portion 50. The joint portion 50 covers the entire tip surface 22a (tip) of the suppression portion 22. Furthermore, in a cross section perpendicular to the thickness direction Z, the shape of the constricted portion 51, where the area of ​​the joint portion 50 is smallest, is larger than the cross-sectional shape of the tip surface 22a of the suppression portion 22. In other words, the minimum outer diameter D51 of the outer peripheral surface of the constricted portion 51 is larger than the outer diameter D22 of the tip surface 22a, which is the outer diameter of the tip of the suppression portion 22. The minimum outer diameter D51 of the outer peripheral surface of the constricted portion 51 may be more than twice the outer diameter D22 of the tip surface 22a, which is the outer diameter of the tip of the suppression portion 22. Furthermore, as in this embodiment, the minimum outer diameter D51 of the outer peripheral surface of the constricted portion 51 may be larger than the outer diameter D220 of the base end 22c of the suppression portion 22. The outer peripheral surface 52 of the joint portion 50 is separated from the first member 10 and the second member 20 and is not blocked by the first member 10 or the second member 20. More specifically, the outer peripheral surface 52 of the joint portion 50 is not blocked by other members over the entire circumferential area of ​​the outer peripheral surface 52.

[0042] The above is a schematic configuration of the joint structure 1. Next, an example of a method for manufacturing the joint structure 1 will be described.

[0043] 2A , when manufacturing the joint structure 1, first, adhesive 40 that will become the joint 50 is applied to the underside 10 a of the first member 10 or the suppression portion 22 of the second member 20. When applied, the adhesive 40 is viscous but not hardened.

[0044] Next, the first member 10 and the second member 20 are placed opposite each other in the plate thickness direction Z, so that the adhesive 40 comes into contact with the underside 10a of the first member 10 and at least the suppressing portion 22 of the second member 20. In this state, welding or hemming is performed to join the outer peripheral edge of the first member 10 and the outer peripheral edge of the second member 20, so that the first member 10 and the second member 20 become an integrated member.

[0045] Subsequently, as shown in FIG. 2B , a large load F acts on the center of the first member 10 toward the second member 20, for example, by supplying high-pressure shower water to the upper surface 10b of the first member 10 for cleaning. This load F causes the first member 10 to bend, reducing the clearance C between the first member 10 and the second member 20. In particular, the smaller the thickness of the first member 10 is for weight reduction, the greater the bending of the first member 10 and the greater the reduction in the clearance C. Due to the reduction in the clearance C, the adhesive 40 is compressed between the first member 10 and the second member 20, and the adhesive 40 spreads to cover the entire suppression portion 22 and also contacts the bearing surface 23 of the second member 20. At this time, the suppression portion 22 approaches or comes into contact with the first member 10, forming a path between the first member 10 and the second member 20 that can support the large load F. Therefore, the presence of the suppressing portion 22 prevents the distance between the seat surface 23 of the second member 20 and the first member 10 from becoming any smaller.

[0046] When the load F is removed, for example by stopping the supply of shower water, the clearance C between the first member 10 and the second member 20 returns to the state it was in before the load F was applied, as shown in Figure 2C. At this time, because the suppression section 22 prevents the clearance C between the first member 10 and the second member 20 from becoming excessively small, the adhesive 40 is not excessively crushed, which would cause a shortage of the outer periphery of the adhesive 40. After the load F is removed, the adhesive 40 hardens through a paint baking process or the like for the first member 10 and the second member 20, forming the joint 50.

[0047] As described above, according to this embodiment, the suppression portion 22 is formed in the target region A10, for example, in the joining region A11, thereby preventing excessive crushing of the uncured adhesive 40 due to a decrease in the clearance C between the first member 10 and the second member 20. Therefore, even in the joint 50 formed by the cured adhesive 40, deficiency at the outer periphery can be prevented. In particular, when the thickness of the first member 10 is reduced to reduce weight, deficiency of the adhesive 40 (joint 50) is likely to occur due to a temporary large decrease in the clearance C. However, this configuration more reliably prevents such deficiency. Therefore, the inherent joining performance of the joint 50 can be exhibited. Furthermore, the minimum outer diameter D51 of the constricted portion 51 is larger than the outer diameter D22, which is the outer diameter of the tip of the suppression portion 22. This configuration ensures a large cross-sectional area of ​​the joint 50, even in the constricted portion 51. Therefore, the inherent joining performance of the joint 50 can be exhibited.

[0048] Furthermore, according to the present embodiment, the suppression portion 22 is provided in a portion of the target region A10. With this configuration, when the uncured adhesive 40 spreads as the clearance C decreases, the suppression portion 22 can suppress excessive spreading of the adhesive 40. More specifically, when the uncured adhesive 40 spreads as the clearance C decreases, the presence of the suppression portion 22 allows a region of thick adhesive 40 to remain. This prevents defects such as breaks from occurring in the outer periphery of the adhesive 40 when the clearance C returns to its original size. If the suppression portion 22 were not present and the area where the suppression portion 22 would be located were flat, the uncured adhesive 40 would spread excessively as the clearance C decreases. This would result in a thinner overall thickness of the adhesive 40, and the clearance C would return to its original size after the adhesive 40 thinned, causing defects such as breaks in the adhesive 40 (bonding portion 50). According to this embodiment, the suppression section 22 can more reliably suppress the shortage of the adhesive 40 described above.

[0049] Furthermore, according to the present embodiment, the suppression portion 22 protrudes from the flat portion 21 toward the first member 10 in the target area A10. With this configuration, a simple configuration in which a part of the flat portion 21 protrudes toward the first member 10 can suppress deficiency of the adhesive 40 (bonding portion 50).

[0050] Furthermore, in this embodiment, the joint 50 covers the entire suppression portion 22. With this configuration, when the adhesive 40 that forms the joint 50 is expanded due to a temporary decrease in the clearance C, the suppression portion 22 functions as a pillar that passes through the inside of the adhesive 40. Therefore, more of the load F from the first member 10 can be borne by the suppression portion 22, and by reducing the load on the adhesive 40, it is possible to more reliably suppress depletion of the outer periphery of the adhesive 40 that forms the joint 50.

[0051] Furthermore, in this embodiment, the outer diameter D22 of the suppression portion 22 is equal to or less than half the outer diameter D50 of the joint portion 50. With this configuration, a space can be secured around the outer periphery of the suppression portion 22 for the adhesive 40 to be appropriately expanded when the clearance C temporarily decreases. This prevents the adhesive 40 from being excessively crushed. As a result, it is possible to prevent the outer periphery of the joint portion 50 from becoming depleted.

[0052] Furthermore, in this embodiment, the outer peripheral surface 52 of the joint 50 is spaced apart from the first member 10 and the second member 20. With this configuration, when the clearance C temporarily decreases, the deformation of the adhesive 40 is not hindered by the first member 10 and the second member 20. This makes it possible to prevent the outer peripheral portion of the adhesive 40 (joint 50) from being damaged and causing defects.

[0053] Furthermore, in this embodiment, the first member 10 is an outer panel of an automobile, the second member 20 is an inner member joined to the outer panel by the joint 50, and the suppression portion 22 is provided on the inner member. With this configuration, it is possible to reduce the thickness of the outer panel to achieve a lighter automobile, while suppressing a shortage of adhesive 40 at the outer periphery due to a temporary decrease in clearance C. This increases the support rigidity of the joint 50, and further increases the tensile rigidity of the first member 10, which is the outer panel.

[0054] The embodiments of the present disclosure have been described above. However, the present disclosure is not limited to the above-described embodiments. Various modifications of the present disclosure are possible within the scope of the claims. Note that the following mainly describes configurations that differ from the above-described embodiments and modifications, and similar configurations are designated by similar reference numerals and detailed description thereof is omitted.

[0055] <Modification 1> In the above embodiment, an example has been described in which the seat surface 23 and the suppression portion 22 are formed on the flat portion 21. However, this is not necessarily the case. Fig. 3 is a cross-sectional view of the main portion of Modification 1. As shown in Fig. 3, a convex base 24 may be formed on the flat portion 21, and the suppression portion 22 may be formed on this convex base 24.

[0056] In this case, the second member 20 has a flat portion 21, a convex base 24 protruding from the flat portion 21 toward the first member 10 in the target area A10, and a suppression portion 22 formed on the convex base 24.

[0057] The convex base 24 is formed in a shape that is convex from the flat portion 21 toward the first member 10. The shape of the convex base 24 is not limited to a specific shape as long as it is formed in a shape that is convex from the flat portion 21 toward the first member 10. The convex base 24 may be formed in a truncated cone shape or a truncated polygonal pyramid shape. A seat surface 23 that comes into contact with the joint portion 50 is formed on the upper surface of the convex base 24.

[0058] According to this first modification, the provision of the convex seat 24 on the second member 20 can further increase the bending rigidity and torsional rigidity of the second member 20. As a result, the bending rigidity and torsional rigidity of the first member 10 and the second member 20 as a whole, which are supported by the second member 20, can further increase.

[0059] 4A shows a completed state of the joint structure 1, and FIG. 4B shows a state during the manufacturing of the joint structure 1. As shown in FIG. 4A, a recessed seat 25 may be formed in the flat portion 21, and the suppression portion 22 may be formed in this recessed seat 25.

[0060] In this case, the second member 20 includes a flat portion 21 , a recessed base 25 recessed from the flat portion 21 in the target area A10 , and a suppression portion 22 formed on the recessed base 25 .

[0061] The recessed base 25 is formed in a shape recessed in a direction away from the first member 10. The specific shape of the recessed base 25 is not limited as long as the flat portion 21 is recessed in the plate thickness direction Z. The recessed base 25 may be formed in a truncated cone shape or a truncated polygonal pyramid shape. A seat surface 23 that comes into contact with the joint 50 is formed on the bottom surface of the recessed base 25. The suppression portion 22 is disposed in the joint region A11 of the target region A10 and protrudes from the recessed base 25 of the second member 20 toward the first member 10. The width of the recessed base 25 (the length in the direction perpendicular to the plate thickness direction Z) is set to a wide value of, for example, 100 mm or more, and the distance to an adjacent joint 50 (not shown) is increased.

[0062] The height H22 of the suppression portion 22 is less than the depth H25 of the recessed seat 25. As a result, the suppression portion 22 is located further back (lower) than the flat portion 21. The clearance C between the first member 10 and the second member 20 is the clearance between the lower surface 10a of the first member 10 and the tip surface 22a, which is the tip of the suppression portion 22. The clearance C may be larger than the difference (H25-H22) between the depth H25 of the recessed seat 25 and the height H22 of the suppression portion 22.

[0063] Furthermore, the clearance C (the distance between the lower surface 10a of the first member 10 and the tip surface 22a, which is the tip of the suppression portion 22) is larger than the clearance E between the lower surface 10a of the first member 10 and the upper surface 21a of the flat portion 21 of the second member 20. It is preferable that the clearance C is at least twice the clearance E. The reason for this is that when the gap between the first member 10 and the second member 20 becomes smaller, a larger area can be secured into which the deformed portion of the adhesive 40 (joint portion 50) can escape.

[0064] Even with this configuration, during manufacturing of the joined structure 1, a large load F may act on the center of the first member 10 toward the second member 20, for example, due to the supply of high-pressure shower water for cleaning to the upper surface 10b of the first member 10. This load F reduces the clearance C between the first member 10 and the second member 20, as shown in FIG. 4B . As a result, the adhesive 40 disposed between the first member 10 and the suppression portion 22 is compressed between the first member 10 and the second member 20, expands to cover the entire suppression portion 22, and also contacts the bearing surface 23 of the second member 20. At this time, as the suppression portion 22 approaches or comes into contact with the first member 10, a path capable of supporting the large load F between the first member 10 and the second member 20 is formed. This prevents the clearance C between the first member 10 and the second member 20 from becoming excessively small.

[0065] As described above, according to the configuration of Modification 2, the suppression portion 22 is formed in the recessed seat 25 of the second member 20 and protrudes from the second member 20 toward the first member 10. According to this configuration, the provision of the recessed seat 25 in the second member 20 can further increase the bending rigidity and torsional rigidity of the second member 20. As a result, the bending rigidity and torsional rigidity of the first member 10 and the second member 20 as a whole, which are supported by the second member 20, can be further increased.

[0066] Alternatively, the convex pedestal 24 shown in the first modified example may be formed on the concave pedestal 25 , and the suppressing portion 22 may be formed on this convex pedestal 24 .

[0067] 5A shows a completed state of the joined structure 1, and FIG. 5B shows a state during the manufacturing of the joined structure 1. As shown in FIG. 5A, a recessed seat 25 may be formed in the flat portion 21, and a suppression portion 22 may be formed in the flat portion 21 in a peripheral region A12 of the recessed seat 25.

[0068] In this case, the second member 20 includes a flat portion 21 , a recessed seat 25 recessed from the flat portion 21 in the target area A10 , and a suppression portion 22 formed on the flat portion 21 .

[0069] In Modification 3, the suppression portion 22 is disposed in the peripheral region A12 of the target region A10, and protrudes from the flat portion 21 of the second member 20 toward the first member 10. The width of the recessed base 25 (the length in the direction perpendicular to the plate thickness direction Z) is set to a relatively small value of, for example, several tens of millimeters or more. It is preferable that a plurality of suppression portions 22 are provided in the circumferential direction of the recessed base 25. The suppression portions 22 are spaced apart from the joint portion 50 and do not contact the joint portion 50.

[0070] Even with this configuration, during manufacturing of the joined structure 1, a large load F is applied to the center of the first member 10 toward the second member 20, as shown in FIG. 5B , for example, by supplying high-pressure shower water for cleaning to the upper surface 10b of the first member 10. This load F reduces the clearance C between the first member 10 and the second member 20. As a result, the adhesive 40 is compressed between the first member 10 and the second member 20. At this time, the suppression portion 22 comes into contact with the first member 10, forming a path between the first member 10 and the second member 20 that can support the large load F. This prevents the clearance C between the first member 10 and the second member 20 from becoming excessively small.

[0071] <Modification 4> In the above-described embodiment and modification, a single joint 50 has been mainly described. In these embodiments and modification, a plurality of joints 50 may be arranged side by side. Fig. 6A is a plan view of the main part of modification 4 showing a configuration in which a plurality of joints 50 are arranged side by side, and Fig. 6B is a schematic vertical cross-sectional view of the configuration shown in Fig. 6A.

[0072] As shown in FIGS. 6A and 6B , a plurality of bonding portions 50 may be arranged side by side on a single convex pedestal 26. The convex pedestal 26 is formed on the second member 20. The convex pedestal 26 is formed, for example, in the shape of a hexagonal truncated pyramid, with a through-hole 26a formed in the upper portion. The plurality of convex pedestals 26 are arranged, for example, in a close-packed arrangement, and a flat portion 21 is formed on the upper surface of each convex pedestal 26. In this case, the flat portion 21 has a hexagonal annular surface. A plurality of bonding portions 50 are arranged side by side on each flat portion 21. For example, one bonding portion 50 and suppression portion 22 are formed on each side of the flat portion 21, and the suppression portion 22 is arranged in the bonding region A11. With this arrangement, the plurality of bonding portions 50 are arranged in a ring shape.

[0073] In this way, by arranging a plurality of joints 50 in a line, the support rigidity of the first member 10 can be increased, and therefore the tensile rigidity of the first member 10 can be increased.

[0074] Furthermore, since the multiple joints 50 are arranged in a ring shape, the support rigidity of the first member 10 can be increased, and therefore the tensile rigidity of the first member 10 can be increased.

[0075] The convex pedestal 26 is not limited to a hexagonal truncated pyramid, and may be a polygonal truncated pyramid shape other than a hexagon, or may be a truncated cone shape. The multiple convex pedestals 26 do not have to be closely packed. The joining structure of Modifications 2 and 3 may also be applied to the convex pedestal 26.

[0076] The present disclosure is widely applicable to joining structures.

[0077] REFERENCE SIGNS LIST 1 Joint structure 10 First member 20 Second member 21 Flat portion 22 Suppression portion 24 Convex base 25 Concave base 26 Convex base 50 Joint portion 51 Neck portion A10 Target area A11 Joint area A12 Peripheral area D22 Outer diameter of tip of suppression portion D51 Minimum outer diameter of neck portion

Claims

1. A joining structure comprising: a first member; a second member arranged opposite the first member; and a joining portion that joins the first member and the second member by adhesive, wherein a suppression portion that suppresses approach between the first member and the second member is provided in a target area including a joining area where the joining portion is arranged and a peripheral area around the joining area, the suppression portion protruding from the second member toward the first member, the joining portion having a constricted portion midway in the direction in which the first member and the second member face each other, and the minimum outer diameter of the constricted portion being larger than the outer diameter of the tip of the suppression portion.

2. The joint structure according to claim 1, wherein the suppression portion is provided in a portion of the target area.

3. A joining structure as described in claim 1, wherein the second member includes a flat portion, and the suppression portion protrudes from the flat portion toward the first member in the target area.

4. A joining structure as described in claim 1, wherein the second member includes a flat portion and a convex base that protrudes from the flat portion toward the first member in the target area, and the suppression portion protrudes from the convex base toward the first member.

5. A joining structure as described in claim 1, wherein the second member includes a flat portion and a recessed base recessed from the flat portion in the target area, and the suppression portion protrudes from the second member toward the first member in the target area.

6. The joint structure according to claim 1, wherein the joint portion covers the entire restraining portion.

7. The joint structure according to claim 1, wherein the outer diameter of the suppression portion is equal to or less than half the outer diameter of the joint portion.

8. The joint structure according to claim 1, wherein a plurality of the joints are arranged side by side.

9. The joint structure according to claim 8, wherein the plurality of joints are arranged in an annular shape.

10. The joint structure according to claim 1, wherein the outer peripheral surface of the joint is spaced apart from the first member and the second member.

11. A joining structure as described in any one of claims 1 to 10, wherein the first member is an outer panel of an automobile, the second member is an inner member joined to the outer panel by the joining portion, and the suppression portion is provided on the inner member.

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