Bonding structure, method for manufacturing the same, and outer body for electric wire

Abstract

This invention provides a bonding structure and a method for manufacturing the same, as well as an outer casing for electrical wires using the bonding structure. The bonding structure allows resin boards to be bonded together even without requiring excessive resin board portions for bonding, and also offers excellent operability when bonding the resin boards. The bonding structure 1 has a joint portion 10 formed by welding a first resin board 21 with a surface portion 22 made of a first resin and a second resin board 23 with a surface portion 24 made of a second resin. The first resin of the bonding structure 1 is a foamed resin, and the second resin is either a non-foamed resin or a foamed resin. The joint portion 10 has a welding recess 25 on the surface 22a of the surface portion 22 and a weld overlay portion 27 formed by the melting and solidification of at least the first resin (either the first or second resin) on the inner corner 10a of the back surface 22b.

Description

Technical Field

[0001] This invention relates to a joint structure and a method for manufacturing the same, as well as an outer casing for electrical wires. Background Technology

[0002] A wire casing is used around the periphery of wiring harnesses installed in vehicles, etc., to protect the wiring harnesses from external damage. The wire casing protects the wires from external damage by covering the outer periphery of the wires.

[0003] As a protective casing for such wiring harnesses, patent documents 1 and 2 describe, for example, a casing for wires that is installed on the periphery of a wire by bending a thermoplastic resin foam sheet to form a cylindrical receiving portion.

[0004] The outer casing for the wire in Patent Document 1 is constructed in such a way that it has a plurality of wall portions extending along the extension direction of the wire and forming a receiving portion for receiving the wire. These plurality of wall portions have an outer cover wall portion, an inner cover wall portion overlapping and joined with the outer cover wall portion, and side wall portions adjacent to both ends of the inner cover wall portion, and the inner cover wall portion is supported by the side wall portions at both ends.

[0005] Furthermore, in the outer casing for an electrical wire in Patent Document 2, the wall portion constituting the receiving portion includes a first wall portion having a protrusion and a second wall portion having a hole. Here, the receiving portion is configured such that at least one of the protrusion and the hole is deformed so that the protrusion is inserted into the hole, thereby engaging the first wall portion with the second wall portion.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2019-13107

[0009] Patent Document 2: Japanese Patent Application Publication No. 2020-89041 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] In the outer casing for electrical wires described in Patent Documents 1 and 2, a cylindrical receiving portion is formed by stacking and joining the surfaces of resin plates such as thermoplastic resin foam sheets, or by engaging the protrusions and holes formed on the resin plates.

[0012] In this regard, if the resin boards can be joined without overlapping their surfaces, the area of ​​resin boards required to form the joining structure for the electrical wire casing, etc., can be reduced, which is preferable in terms of reducing material costs. Furthermore, if the resin boards can be joined without forming protrusions and holes in them, the number of steps required to form the joining structure for the electrical wire casing, etc., is reduced, which is preferable in terms of improved operability.

[0013] The above situation is not limited to the outer casing of wires, but also applies to other bonded structures formed by bonding a first resin made of foamed resin with a second resin made of non-foamed resin or foamed resin.

[0014] The object of the present invention is to provide a bonding structure and a method for manufacturing the same, as well as an outer casing for wires using the bonding structure, which can bond resin boards together even without providing too many resin board portions for bonding, and also has excellent operability when bonding resin boards.

[0015] Methods for solving problems

[0016] The inventors of this application discovered that, as a joining structure, by providing a welding recess on the surface of the first resin plate in a state where the surface of the first resin plate formed by welding is aligned with the end face of the second resin plate formed by welding, and by providing a weld overlay portion formed by melting and solidifying at least the first resin among the first and second resins at the inner corner of the back side, it is possible to join resin plates with excellent operability without overlapping the surfaces of the resin plates, thus completing the present invention.

[0017] That is, the main structure of the present invention is as follows.

[0018] (1) A joint structure having a joint formed by welding a face of a first resin plate formed of a first resin and an end face of a second resin plate formed of a second resin, wherein the first resin is a foamed resin and the second resin is a non-foamed resin or a foamed resin, and the joint has a welding recess on its surface and an overlay portion formed by melting and solidifying at least the first resin of the first resin and the second resin at the inner corner of its back side.

[0019] (2) The joint structure as described in (1) above, wherein the minimum thickness of the first resin when measured at the bottom surface of the aforementioned welding recess is in the range of 0.1 mm to 2.0 mm.

[0020] (3) The joint structure as described in (1) or (2) above, wherein the minimum thickness of the joint when measured from the position of the aforementioned welding recess is 0.1 mm or more.

[0021] (4) The joint structure as described in any one of (1) to (3) above, wherein the mating angle between the face of the first resin plate and the end face of the second resin plate is in the range of 45° to 90° when measured on the acute angle side.

[0022] (5) The bonding structure as described in any one of (1) to (4) above, wherein one or both of the first resin and the second resin contain polypropylene resin.

[0023] (6) An outer casing for an electrical wire, which is an outer casing for an electrical wire installed on the outer periphery of an electrical wire, wherein the aforementioned outer casing for an electrical wire has a connecting structure as described in any one of (1) to (5) above.

[0024] (7) A wiring harness with an outer casing, comprising a wiring harness and an outer casing for wires as described in (6) above, wherein the outer casing for wires is mounted on the outer periphery of the wiring harness.

[0025] (8) A method for manufacturing a joint structure, comprising: a positioning step, wherein an end face of a second resin plate formed of a second resin is positioned and held in a state of being engaged with the back face of a first resin plate formed of a first resin; a welding head pressing step, wherein, in a state of being engaged with the end face of the first resin plate and the end face of the second resin plate, a front end of a welding head is pressed against the surface side of the end face of the first resin plate; and a joint forming step, wherein ultrasonic waves are emitted from the welding head, and welding is performed in a state of being engaged with the end face of the first resin plate and the end face of the second resin plate to form a joint, wherein the first resin is a foamed resin, the second resin is a non-foamed resin or a foamed resin, and the joint has a welding recess on its surface and an overlay portion formed by melting and solidifying at least the first resin among the first resin and the second resin at the inner corner of its back face.

[0026] (9) The manufacturing method of the joint structure as described in (8) above, wherein the front end of the aforementioned welding head is formed as a convex protrusion.

[0027] (10) The method of manufacturing a joint structure as described in (8) or (9) above, wherein at least a portion of the surface of the front end of the aforementioned weld head is formed as a curved surface.

[0028] (11) The method of manufacturing a joint structure as described in any one of (8) to (10) above, wherein at least a portion of the surface of the front end of the aforementioned weld head is formed by a plurality of irregularities.

[0029] Invention Effects

[0030] According to the present invention, a bonding structure and a method for manufacturing the same thereof, as well as an outer casing for wires using the bonding structure, are provided. The bonding structure enables resin boards to be bonded together even without providing excessive resin board portions for bonding, and also provides excellent operability when bonding resin boards. Attached Figure Description

[0031] [ Figure 1 ] Figure 1 To show a schematic diagram of the main parts of the joint structure, including the joint, Figure 1 (a) is a top view. Figure 1 (b) is Figure 1 (a) is a cross-sectional view (cross section view).

[0032] [ Figure 2 ] Figure 2 This is a schematic top view of the welding recess in the joint portion of the joint structure that constitutes various embodiments. Figure 2 (a) shows the case where the bottom surface of the weld recess is formed in a striped, uneven shape. Figure 2 (b) shows the case where the bottom surface of the weld recess is formed with an irregular concave-convex shape, and Figure 2 (c) shows the case where the bottom surface of the weld recess is formed by a flat surface.

[0033] [ Figure 3 ] Figure 3 A top view showing the shape of the welding recess in the joint of a joint structure according to another embodiment.

[0034] [ Figure 4 ] Figure 4 This is a schematic diagram showing the main parts of the joint structure, including the joint portion, of another embodiment of the joint structure. Figure 4 (a) shows a case where the surface of the weld overlay portion of the joint is formed into a concave shape when viewed from the inside corner, and Figure 4 (b) shows the case where the surface of the weld overlay portion of the joint is formed into a convex shape when viewed from the inside angle.

[0035] [ Figure 5 ] Figure 5 A schematic perspective view showing the structure of the outer casing for electrical wires.

[0036] [ Figure 6 ] Figure 6 This is a flowchart of a method for manufacturing a joint structure.

[0037] [ Figure 7 ] Figure 7This diagram illustrates a method for manufacturing a joint structure, specifically a schematic diagram illustrating an example of the welding head pressing process and the joint formation process.

[0038] [ Figure 8 ] Figure 8 This is a schematic diagram illustrating an example of the shape of the front end of a welding head used in a method for manufacturing a joint structure according to other embodiments. Figure 8 (a) shows the case where the front end of the weld joint has an uneven surface formed by knurling. Figure 8 (b) is a case where the front end of the weld joint has a convex protrusion, and the front end face of the protrusion has an uneven surface formed by sandblasting. Figure 8 (c) shows a case where the front end of the welding head has a convex protrusion, and the front end of the protrusion has a convex surface formed by rounding.

[0039] [ Figure 9 ] Figure 9 The figure is a cross-section perpendicular to both the first resin plate and the second resin plate, taken for viewing the joint structure of Example 1 of the present invention. Detailed Implementation

[0040] Next, the joining structure and the outer casing for wires according to several embodiments of the present invention will be described below.

[0041] Figure 1 To show a schematic diagram of the main parts of the joint structure, including the joint, Figure 1 (a) is a top view. Figure 1 (b) is Figure 1 (a) is a cross-sectional view (cross-sectional view). Additionally, Figure 2 This is a schematic top view of the welding recess in the joint portion of the joint structure that constitutes various embodiments. Figure 2 (a) shows the case where the bottom surface of the weld recess is formed in a striped, uneven shape. Figure 2 (b) shows the case where the bottom surface of the weld recess is formed with an irregular concave-convex shape, and Figure 2 (c) shows the case where the bottom surface of the weld recess is formed by a flat surface. Figure 3 This is a top view showing the shape of the welding recess in the joint of a joint structure according to another embodiment. Additionally, Figure 4 This is a schematic diagram showing the main parts of the joint structure, including the joint portion, of another embodiment of the joint structure. Figure 4 (a) shows a case where the surface of the weld overlay portion of the joint is formed into a concave shape when viewed from the inside corner, and Figure 4 (b) shows the case where the surface of the weld overlay portion of the joint is formed into a convex shape when viewed from the inside angle.

[0042] 1. Regarding the joint structure

[0043] like Figure 1 As described, the joining structure 1 has a joint portion 10 formed by welding the surface 22 of a first resin plate 21 formed of a first resin with the end portion 24 of a second resin plate 23 formed of a second resin. The first resin of the joining structure 1 is a foamed resin, and the second resin is a non-foamed resin (solid resin) or a foamed resin. The joint portion 10 has a welding recess 25 on the surface 22a of the surface 22 of the first resin plate 21, and an overlay portion 27 formed by melting and solidifying at least the first resin of the first resin and the second resin at the inner corner 10a of the back surface 22b of the surface 22.

[0044] Therefore, by forming a welding recess 25 on the surface 22a of the first resin plate 21's surface portion 22, the first resin is extruded along the depth direction of the welding recess 25, melts and flows to the vicinity of the end portion 24 of the second resin plate 23, and is welded to the end portion 24 of the second resin plate 23. Thus, the bonding area between the end portion 24 of the second resin plate 23 and the surface portion 22 of the first resin plate 21 becomes larger. In particular, the second resin constituting the end portion 24 of the second resin plate 23 also melts together with the first resin constituting the surface portion 22 of the first resin plate 21, thereby forming a layer of a mixture of the first and second resins at the boundary between the first resin plate 21 and the second resin plate 23. Therefore, the first resin plate 21 and the second resin plate 23 are joined by welding. Therefore, even without joining the surface of the first resin board 21 to the surface of the second resin board 23, the first resin board 21 and the second resin board 23 can be joined by welding. Thus, a joining structure 1 can be provided that allows the first resin board 21 and the second resin board 23 to be joined even without providing too many resin board portions, and that the operability of joining them is also excellent.

[0045] Here, "welding" refers to resin welding. In this embodiment, ultrasonic welding is preferably used as the resin welding method. Resin welding is a technique that joins multiple resin plates or multiple parts of a single resin plate formed of thermoplastic resin by heating them above their melting point. Ultrasonic welding, on the other hand, is a technique that joins multiple resin plates or multiple parts of a single resin plate by melting them together using ultrasonic vibration and pressure.

[0046] (Regarding the first resin board and the second resin board)

[0047] The first resin board 21 and the second resin board 23 are respectively composed of the first resin and the second resin.

[0048] Here, the first resin plate 21 and the second resin plate 23 can be made of the same resin plate or different resin plates. When the first resin plate 21 and the second resin plate 23 are made of the same resin plate, they are formed by bending one resin plate. In this case, the first resin plate 21 is formed by the surface portion of the resin plate, and the second resin plate 23 is formed by the end portion of the same resin plate. This further reduces the number of parts constituting the joining structure 1, thus further improving the operability of forming the joining structure.

[0049] The resin of at least the first resin constituting the first resin plate 21 and the second resin plate 23 is preferably a thermoplastic resin, such as polyethylene resin, polypropylene resin, polycarbonate resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyamide resin, polyphenylene sulfide resin, polystyrene resin, polyvinyl chloride resin, polyvinyl acetate resin, polytetrafluoroethylene resin, acrylic resin, etc. Here, it is preferable that one or both of the first resin and the second resin contain polypropylene resin.

[0050] The first resin and the second resin can be made of the same type of resin or different types of resin. In particular, by making the first resin and the second resin the same type of resin, the bonding strength between the first resin plate 21 and the second resin plate 23 can be further improved.

[0051] In the first and second resins, various additives commonly used in resins may be added, depending on the intended application. Additives may be used without particular limitation, such as one or more of the following: fillers, antioxidants, stabilizers, flame retardants, metal passivators, ultraviolet absorbers, light stabilizers, plasticizers, nucleating agents, solubilizers, transparentizing agents, antistatic agents, lubricants, etc.

[0052] At least the first resin, of the first resin and the second resin, is composed of a foaming resin. Therefore, when the resin is melted, air bubbles are expelled from the resin, causing it to shrink, thus preventing the area where the resin is melted from expanding in the direction of the surface of the first resin plate 21 and the second resin plate 23. In particular, when the welding recess 25 is formed on the first resin plate 21, the first resin is easily squeezed out along the depth direction of the welding recess 25. As a result, it promotes the solidification of the resin being welded and suppresses excessive melt flow of the resin, preventing the resin from flowing out of the joint 10.

[0053] The density of the foaming resin is not specifically limited here; for example, it can be 200 kg / m³. 3 Above 1000kg / m 3The following range. In particular, from the viewpoint of making application products with joint structure 1, such as wire casings and wiring harnesses with casings, lighter and improving the buffering effect against mechanical impact, the density of the foamed resin is preferably 1000 kg / m³. 3 The following is more preferably 700 kg / m 3 The following is a further preferred value: 500 kg / m 3 Below. On the other hand, from the viewpoint of ensuring the mechanical strength of the foamed resin and promoting the melt flow of the foamed resin when forming the weld recess 25, the density of the foamed resin is preferably 200 kg / m³. 3 above.

[0054] On the other hand, the second resin constituting the second resin plate 23 can be made of a non-foamed resin, or it can be made of the foamed resin described above. In particular, by making the second resin of a non-foamed resin, the bonding strength between the first resin plate 21 and the second resin plate 23 can be further improved.

[0055] The thickness t1 of the first resin plate 21 and the thickness t2 of the second resin plate 23 are not particularly limited. For example, from the viewpoint of further improving the balance between welding ease and mechanical strength based on the welding recess 25, the thicknesses are preferably 0.5 mm or more and 5.0 mm or less, and particularly preferably 1.0 mm or more and 2.0 mm or less.

[0056] (Regarding the joint)

[0057] The joining structure 1 has a joint portion 10 formed by welding the surface portion 22 of a first resin plate 21 formed of a first resin with the end portion 24 of a second resin plate 23 formed of a second resin. Here, as... Figure 1 As shown, the joint 10 is formed by aligning the end face 24 of the second resin plate 23 with the back face 22 of the first resin plate 21. Figure 1 It is formed by welding in the state of the lower side surface.

[0058] The joint 10 has a welding recess 25 on the surface 22a of the plate surface 22 of the first resin plate 21. Here, the surface 22a of the plate surface 22 is the side that is not mated to the end face 24 of the second resin plate 23. By providing the welding recess 25 in the joint 10, at least the first resin contained in the first resin plate 21 can be extruded and melted along the depth direction of the welding recess 25 to the vicinity of the end face 24 of the second resin plate 23, and the molten resin is welded to the end face 24 of the second resin plate 23 to form the weld overlay 27 described later. It should be noted that the resin that melts and flows due to the formation of the welding recess 25 may contain a second resin in addition to the first resin.

[0059] The bottom surface 26 of the welding recess 25 can also be made of non-foamed resin. In particular, when the first resin is extruded along the depth direction of the welding recess 25 and melts and flows to the vicinity of the end face 24 of the second resin plate 23, most of the first resin located on the bottom surface 26 of the welding recess 25 will also melt. Therefore, most of the bottom surface 26 of the welding recess 25 is formed with non-foamed resin.

[0060] Here, it is preferable to proceed along the thickness direction of the second resin plate 23. Figure 1 The width w of the bottom surface 26 of the welding recess 25 (in the X1 direction) is equal to or greater than the thickness t2 of the second resin plate 23. Preferably, the bottom surface 26 of the welding recess 25 is configured to include both sides of the second resin plate 23 when viewed in the thickness direction (X1 direction). Furthermore, it is preferable that the width w of the bottom surface 26 of the welding recess 25 is greater than the thickness t2 of the second resin plate 23 in a range exceeding 0 mm and less than 1.0 mm. By configuring the welding recess 25 in this way, the resin extruded along the depth direction of the welding recess 25 can easily melt and flow to the vicinity of the end face 24 of the second resin plate 23. On the other hand, the width w of the bottom surface 26 of the welding recess 25 can also be less than the thickness t2 of the second resin plate 23.

[0061] The surface shape of the bottom surface 26 of the welding recess 25 can be formed, for example, as follows: Figure 1 The lattice-like uneven shape described in (a) is formed, as will be described later. This lattice-like uneven shape can be formed by pressing the front end of the weld head, which has been knurled into a diagonal pattern, against the surface 22a of the first resin plate 21. As a result, resin can be easily extruded in the depth direction of the weld recess 25.

[0062] It should be noted that the surface shape of the bottom surface 26 of the welding recess 25 is not limited to Figure 1 The lattice-like concave-convex shape described in (a). For example, it could also be... Figure 2 The striped, uneven shape formed by knurling the front end of the weld head, as described in (a). Alternatively, it could be... Figure 2 (b) describes the irregular, uneven shape formed by using the front end of a sandblasted weld head. Alternatively, it could also be... Figure 2 The flat surface recorded in (c).

[0063] Furthermore, the shape of the welding recess 25 is not limited to Figure 1 The rectangle described in (a) could also be, for example, a rectangle. Figure 3 The circle shown.

[0064] like Figure 1As shown, the joint 10 has an overlay portion 27 formed by the melting and solidification of at least the first resin, which is formed by the surface portion 22 of the first resin plate 21 and the end portion 24 of the second resin plate 23, at the inner corner 10a of the back surface 22b. This results in a larger joint area between the end portion 24 of the second resin plate 23 and the surface portion 22 of the first resin plate 21, thus enabling the first resin plate 21 and the second resin plate 23 to be joined by welding.

[0065] The shape of the weld overlay 27 is not particularly limited; for example, it can be as follows: Figure 4 As described in (a), the surface of the weld overlay portion 27E of the joint 10E is concave when viewed from the inner angle 10a, and may also be as described in the diagram. Figure 4 As described in (b), the surface of the weld overlay portion 27F of the joint 10F is convex when viewed from the inner angle 10a.

[0066] For the joint 10, the minimum thickness t3, measured from the position of the welding recess 25 and independent of the measurement direction, is preferably 0.1 mm or more, and more preferably 0.3 mm or more. Here, the preferred lower limit of the minimum thickness t3 of the joint 10 can be 0.1 mm or 0.10 mm. The minimum thickness t3 of the joint 10 measured from the position of the welding recess 25 can be less than 0.1 mm, but by setting it to 0.1 mm or more, even near the area where the welding recess 25 is formed, the thickness of the joint 10 (the overall thickness of the first resin plate 21 and the second resin plate 23) can be ensured, thus reducing the likelihood of breakage of the first resin at the joint 10. On the other hand, the upper limit of the minimum thickness t3 of the joint 10 measured from the position of the welding recess 25 is preferably 2.0 mm, and more preferably a value that is about 0.1 mm smaller than the plate thickness (the thickness of the first resin plate 21). Here, when the upper limit of the minimum thickness t3 is set to a value approximately 0.1 mm less than the plate thickness, for example, when the thickness of the first resin plate 21 is 1.5 mm, the upper limit of the minimum thickness t3 of the joint 10 can be set to 1.4 mm. Alternatively, for example, when the thickness of the first resin plate 21 is 1.0 mm, the upper limit of the minimum thickness t3 of the joint 10 can be set to 0.9 mm. Thus, by setting the upper limit of the minimum thickness t3 of the joint 10, measured from the position of the welding recess 25, to 2.0 mm or a value approximately 0.1 mm less than the plate thickness, resin is more easily extruded when the welding recess 25 is formed, thereby improving the bonding strength between the first resin plate 21 and the second resin plate 23.

[0067] Furthermore, in the joint 10, the minimum thickness t4 of the first resin along the thickness direction of the first resin plate 21, measured at the bottom surface of the welding recess 25, is preferably 0.1 mm or more, and more preferably 0.3 mm or more. Here, the preferred lower limit of the minimum thickness t4 of the first resin can be set to 0.1 mm or 0.10 mm. The minimum thickness t4 of the first resin at the bottom surface of the welding recess 25 can be less than 0.1 mm, but by setting it to 0.1 mm or more, the breakage of the first resin at the joint 10 is less likely to occur. On the other hand, by making the minimum thickness t4 of the first resin at the bottom surface of the welding recess 25 2.0 mm or less, and more preferably 1.0 mm or less, the resin is easily extruded when forming the welding recess 25, thus further improving the operability when joining the first resin plate 21 and the second resin plate 23. In addition, when forming the joint structure 1 by ultrasonic welding as described later, the end face 24 of the second resin plate 23 can be easily melted by the vibration of the ultrasonic wave U. The minimum thickness t4 of the first resin along the thickness direction of the first resin plate 21 is mostly the thickness of the first resin plate 21 measured at the deepest position of the bottom surface 26 of the welding recess 25, but it can also be the thickness of the first resin plate 21 measured at different positions.

[0068] Furthermore, when measured on the acute angle side, the mating angle between the surface portion 22 of the first resin plate 21 and the end portion 24 of the second resin plate 23 of the joint 10 is preferably in the range of 45° to 90°, and more preferably in the range of 60° to 90°. By ensuring that the mating angle between the surface portion 22 of the first resin plate 21 and the end portion 24 of the second resin plate 23 is within this range, when resin is extruded along the depth direction of the welding recess 25, it is easier for the resin to melt and flow to both sides of the end portion 24 of the second resin plate 23.

[0069] 2. Regarding the outer casing for electrical wires

[0070] The outer casing 30 for the wire is an outer casing for the wire installed on the outer periphery of the wire 4, and it has a connecting structure 1.

[0071] The following is a detailed explanation using accompanying drawings. Figure 5 This is a schematic perspective view showing the structure of the wire casing 30. The wire casing 30 has a wall portion 31 extending along the X2 direction of the wire 4, and a receiving portion 32 formed by and surrounding the wall portion 31 and accommodating the wire 4. By having the aforementioned joining structure 1, the wire casing 30 can be constructed even without providing an excessive amount of resin board for joining, and the operability of forming the wire casing 30 by joining resin boards can be improved. Therefore, a lightweight wire casing 30 that can adequately protect the wire 4 can be obtained. It should be noted that, in Figure 5 In this context, wire 4 is represented by a single cylindrical shape, but wire 4 can also be a wire bundle consisting of two or more wires, such as a wiring harness, or a wire bundle that branches as needed.

[0072] The shape of the outer casing 30 for the electrical wire is not particularly limited, for example, Figure 5 As shown, the wall portion 31 can also be formed by bending a single resin board at multiple bends 30a to 30c. In this case, the wall portion 31 of the wire casing 30 is preferably configured to surround the entire circumference of the wire 4. Thus, by forming the wire casing 30 from a single resin board, the number of joints in the resin board is reduced, thereby enabling more efficient manufacturing of the wire casing 30.

[0073] 3. Wiring bundle with external casing

[0074] The wiring bundle 3 with an outer casing of the present invention includes a wiring bundle 40 composed of wires 4 and the aforementioned outer casing 30 for wires, the outer casing 30 for wires being mounted on the outer periphery of the wiring bundle 40. Thus, the outer casing 30 for wires can protect at least a portion of the electrical wiring bundle constituting the wiring bundle 40, and of a bundle of wires formed by multiple segmented wire bundles extending further from the electrical wiring bundle.

[0075] 4. Manufacturing methods for joint structures

[0076] Next, the manufacturing method of the above-mentioned joint structure 1 will be described. Figure 6 This is a flowchart of a manufacturing method for the joint structure 1. The manufacturing method includes: a positioning step ST1, in which the end face 24 of the second resin plate 23 formed of the second resin is positioned and held in a state where it is engaged with the back side 22b of the face face 22 of the first resin plate 21 formed of the first resin; a welding head pressing step ST2, in which, while the face face 22 of the first resin plate 21 is engaged with the end face 24 of the second resin plate 23, the front end 51 of the welding head 5 is pressed against the face face 22 of the first resin plate 21 from the surface 22a side; and a joint forming step ST3, in which ultrasonic waves U are emitted from the welding head 5, and welding is performed while the face face 22 of the first resin plate 21 and the end face 24 of the second resin plate 23 are engaged to form a joint 10.

[0077] First, a first resin plate 21 formed of a first resin and a second resin plate 23 formed of a second resin are prepared. Here, the first resin constituting the first resin plate 21 is preferably a foamed resin. By using a component formed of foamed resin as the first resin plate 21, after pressing the front end 51 of the welding head 5 against the first resin plate 21 in the welding head pressing step ST2 (described later), when the first resin is melted using ultrasonic waves U in the joint forming step ST3, bubbles detach from the first resin and shrink, and the first resin is easily squeezed out toward the depth direction of the welding recess 25. Therefore, the solidification of the welded resin is promoted, and the melting flow of the first resin beyond the necessary limit is suppressed, making it difficult for the first resin to flow out of the joint 10. On the other hand, the second resin constituting the second resin plate 23 can be any of non-foamed resin and foamed resin.

[0078] A positioning process ST1 is performed on these first resin plates 21 and second resin plates 23. In the positioning process ST1, the end face 24 of the second resin plate 23, formed of the second resin, is positioned and held in a state where it is engaged with the back face 22b of the face face 22 of the first resin plate 21, formed of the first resin. For example, in the case of manufacturing an outer casing 30 for an electrical wire having a connecting structure 1, by positioning the first resin plates 21 and the second resin plates 23 in the positioning process ST1, the receiving portion 32 for receiving the electrical wire 4 can be formed at the desired position and size.

[0079] Regarding the positioning and holding of the surface 22 of the first resin plate 21 and the end face 24 of the second resin plate 23 in the positioning process ST1, their positional relationship can be fixed by using a means to hold them in a specified position (e.g., a special positioning fixture made according to the shape and size of the resin plate) while the surface 22 of the first resin plate 21 is in contact with the end face 24 of the second resin plate 23.

[0080] Figure 7 This diagram illustrates a method for manufacturing a joint structure, specifically a schematic diagram showing an example of the welding head pressing process and the joint formation process. After the positioning process ST1, as... Figure 7 As shown in (a), with the surface 22 of the first resin board 21 and the end face 24 of the second resin board 23 aligned, a welding head pressing process ST2 is performed, in which the front end portion 51 of the welding head 5 is pressed against the surface 22a side of the surface 22 of the first resin board 21. This allows the front end portion 51 of the welding head 5 to be positioned on the surface 22 of the first resin board 21 and the end face 24 of the second resin board 23.

[0081] The front end portion 51 of the welding head 5 is preferably formed as a convex protrusion. As a result, deformation of the base of the welding head 5 is less likely to occur, and when the front end portion 51 of the welding head 5 is pressed against the surface portion 22 of the first resin plate 21 in the welding head pressing step ST2, the force acting on the surface portion 22 of the first resin plate 21 per unit area increases. Therefore, when the welding recess 25 is formed in the joint forming step ST3 described later, the first resin can be easily extruded into the depth direction of the welding recess 25.

[0082] Figure 8 This is a schematic diagram illustrating an example of the shape of the front end of a weld head used in the manufacture of a joint structure according to other embodiments. Figure 8 (a) is a diagram showing a structure with a concave-convex surface formed by knurling at the front end of the weld head. Figure 8 (b) is a diagram showing a structure with a convex protrusion at the front end of the weld head, and the front end face of the protrusion having a concave-convex surface formed by sandblasting. Figure 8 (c) is a diagram showing a structure with a convex protrusion at the front end of the weld head, the front end of which has a convex surface formed by rounding.

[0083] Here, the front end 51 of the welding head 5 can be as follows: Figure 8 As shown in (a), multiple irregularities are formed on at least a portion of the surface by knurling, such as twill or plain knurling. Alternatively, it can be as follows... Figure 8 As shown in (b), a convex protrusion is formed at the front end 51G of the welding head 5G. Alternatively, multiple protrusions and recesses can be formed on at least a portion of the surface of the front end 51G by sandblasting. In this way, by forming multiple protrusions and recesses on the surface of the front ends 51 and 51G of the welding heads 5 and 5G, the contact area with the first resin plate 21 is reduced. This allows the pressure applied to the contact portion with the first resin plate 21 to be concentrated on the protruding portion. Furthermore, in the joint formation process ST3 described later, the vibration of the ultrasonic wave U can also be concentrated on the protruding portion. Therefore, at least the first resin can be easily extruded into the depth direction of the welding recess 25.

[0084] In addition, such as Figure 8As shown in (c), at least a portion of the surface of the front end portion 51H of the welding head 5H can be formed as a curved surface. More specifically, a convex surface that is chamfered by rounding can be formed at the front end of the convex protrusion formed on the front end portion 51H. In this way, by forming a curved surface at the front end portion 51 of the welding head 5, the contact area with the first resin plate 21 is reduced, thereby concentrating the pressure applied to the contact portion with the first resin plate 21. Furthermore, the vibration of the ultrasonic wave U can be concentrated in the joint formation process ST3 described later. Therefore, at least the first resin can be easily extruded along the depth direction of the welding recess 25. Furthermore, by forming a curved surface at the front end 51, when the portion overlapping the plate surface 22 of the first resin plate 21 and the end surface 24 of the second resin plate 23 is pressed against the protruding portion of the curved surface in the front end 51, the end portion of the front end 51 is shallowly pressed in. Therefore, the required size can be easily obtained for the thickness of the first resin plate 21 after the welding recess 25 is formed (especially the minimum thickness t3 of the first resin plate when measured from the position of the welding recess 25).

[0085] Next, as Figure 7 As shown in (b), in the joint formation step ST3, ultrasonic waves U are emitted from the welding head 5, and welding is performed to form the joint 10 while the surface 22 of the first resin plate 21 and the end face 24 of the second resin plate 23 are aligned. Through the vibration of the ultrasonic waves U emitted from the welding head 5, at least the first resin is heated and melted, and the molten resin is extruded from the welding head 5. At this time, a portion of the end face 24 of the second resin plate 23 can melt together with the first resin, forming a mixture with the extruded first resin. The extruded resin melts and flows to the vicinity of the end face 24 of the second resin plate 23, and is welded to the back surface 22b of the surface 22 and the inner angle 10a of the end face 24 of the second resin plate 23, thereby forming the joint 10. At this time, a welding recess 25 is formed in the portion of the surface 22a of the surface 22 of the first resin plate 21 that presses against the welding head 5. At the same time, a weld overlay portion 27 is formed on the inner angle 10a of the end face 24 of the second resin plate 23 formed on the back side 22b of the plate face 22.

[0086] Thus, a joint structure 1 can be obtained in which the joint portion 10 has a welding recess 25 on the surface 22a of the plate surface 22 of the first resin plate 21, and a weld overlay portion 27 formed by melting and solidifying at least the first resin and the second resin at the inner corner 10a of the joint portion 10 located on the back surface 22b of the plate surface 22.

[0087] The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments, and includes all the concepts and methods contained in the claims, and various changes can be made within the scope of the present invention.

[0088] Example

[0089] Next, in order to further clarify the effects of the present invention, examples of the present invention and comparative examples will be described, but the present invention is not limited to these examples.

[0090] [Example 1 of the present invention]

[0091] Both the first resin board 21 and the second resin board 23 use resin with a density of 480 kg / m³. 3 The foamed resin board is formed from foamed polypropylene resin. Here, the thickness t1 of the first resin board 21 and the thickness t2 of the second resin board 23 are both 1.5 mm. It should be noted that, in order to easily confirm the welding status, the first resin board 21 and the second resin board 23 are made of resin boards of different colors.

[0092] For the first resin plate 21 and the second resin plate 23, as a positioning process ST1, the end face 24 of the second resin plate 23, formed of the second resin, is aligned at a right angle with the back surface 22b of the plate face 22 of the first resin plate 21, formed of the first resin. Positioning is performed using a positioning fixture while they are in contact, and their positional relationship is maintained. That is, the alignment angle between the plate face 22 of the first resin plate 21 and the end face 24 of the second resin plate 23 is set to 90°.

[0093] Next, as part of the welding head pressing process ST2, with the surface 22 of the first resin board 21 and the end face 24 of the second resin board 23 aligned, the front end 51 of the welding head 5 is pressed against the surface 22a of the surface 22 of the first resin board 21. Here, the welding head 5 is as follows: Figure 8 As shown in (a), a convex protrusion with a front end face of 2.4 mm in length and 8.0 mm in width is formed at the front end 51. Multiple uneven welding heads are formed on the front end face of this protrusion by knurling with a modulus (m) of 0.2 as specified in JIS B 0951. The front end 51 of this welding head 5 is pressed against the first resin plate 21 and the second resin plate 23 in a manner that overlaps the front end 51 in the short side direction (longitudinal direction) along the thickness direction of the second resin plate 23. At this time, the front end 51 of the welding head 5 extends evenly from the second resin plate 23 in the thickness direction of the second resin plate 23.

[0094] With the front end 51 of the welding head 5 pressed against the first resin plate 21 and the second resin plate 23, as part of the joint formation process ST3, ultrasonic waves U are emitted from the welding head 5. Here, the oscillation of ultrasonic waves U from the welding head 5 is performed by a small welding machine (manufactured by Ultrasonic Industries Co., Ltd., model: P128), with an output power of 100W and a frequency of 28kHz, and the welding head 5 is pressed into the ground at a depth of 0.75mm, thereby welding the first resin plate 21 and the second resin plate 23 to form the joint 10, thus creating the joint structure 1.

[0095] The resulting joint structure 1 was observed in a cross-section perpendicular to both the first and second resin plates, and the results are as follows: Figure 9 As shown. According to Figure 9 The observations show that in the joint formation process ST3, the first resin constituting the first resin plate 21 and the second resin constituting the second resin plate 23 are heated and partially melted by the oscillation of the ultrasonic wave U. The molten first resin is extruded through the welding head 5 in a state where the voids have decreased due to foaming. Here, it is known that the extruded first resin, while forming a mixture with the molten second resin, melts and flows to the vicinity of the end face 24 of the second resin plate 23, and is welded to the back surface 22b of the plate face 22 and the inner angle 10a of the end face 24 of the second resin plate 23 to form a weld overlay 27.

[0096] Furthermore, the joint portion 10 of the obtained joint structure 1 has a welding recess 25 formed on the surface 22a of the plate surface 22 of the first resin plate 21, and a grid-like uneven shape formed on its bottom surface 26. Additionally, the longitudinal and transverse dimensions of the bottom surface 26 of the welding recess 25 are approximately the same as the dimensions of the front end portion 51 of the welding head 5. That is, the width w of the bottom surface 26 of the welding recess 25 along the thickness direction of the second resin plate 23 is approximately 2.4 mm.

[0097] Furthermore, in the obtained joint structure 1, the minimum thickness t3 of the joint 10, measured from the position of the welding recess 25 and independent of the measurement direction, was measured to be 0.75 mm. Additionally, the front end position of the end face 24 of the second resin is located approximately at the same position as the plate face 22 of the first resin plate 21 before the joint 10 is formed, and the minimum thickness t4 of the first resin, measured at the position of the deepest bottom surface 26 in the welding recess 25 and along the thickness direction of the first resin plate 21, was measured to be 0.75 mm.

[0098] For the obtained joint structure 1, the joint strength when the joint 10 was peeled off along the depth direction of the weld recess 25 was measured using an Autograph tensile testing machine (model: AGS-X, 10N-10kN) manufactured by Shimadzu Corporation. The joint strength was measured to be 147 [N].

[0099] [Example 2 of the present invention]

[0100] As the welding head 5, a convex protrusion with a front end face of 2.0 mm in length and 8.0 mm in width is formed at the front end 51. Multiple concave and convex welding heads are formed on the front end face of the protrusion by knurling with a modulus (m) of 0.2 as specified in JIS B 0951. The joint structure 1 is manufactured in the same manner as in Example 1 of the present invention.

[0101] For the joint portion 10 of the obtained joint structure 1, similar to Example 1 of the present invention, a welding recess 25 is formed on the surface 22a of the plate portion 22 of the first resin plate 21, and a grid-like uneven shape is formed on its bottom surface 26. Furthermore, the longitudinal and transverse dimensions of the bottom surface 26 of the welding recess 25 are approximately the same as the dimensions of the front end portion 51 of the welding head 5. That is, the width w of the bottom surface 26 of the welding recess 25 along the thickness direction of the second resin plate 23 is approximately 2.0 mm.

[0102] Furthermore, in the obtained joint structure 1, the minimum thickness t3 of the joint portion 10, measured from the position of the welding recess 25 and independent of the measurement direction, was measured to be 0.75 mm. Additionally, the minimum thickness t4 of the first resin along the thickness direction of the first resin plate 21, measured at the deepest position on the bottom surface 26 of the welding recess 25, was also measured to be 0.75 mm.

[0103] For the obtained joint structure 1, the joint strength was measured using the same measurement method as in Example 1 of the present invention, and the joint strength was measured to be 143 [N].

[0104] [Example 3 of the present invention]

[0105] As the welding head 5, a convex protrusion with a front end face of 1.6 mm in length and 8.0 mm in width is formed at the front end 51. Multiple concave and convex welding heads are formed on the front end face of the protrusion by knurling with a modulus (m) of 0.2 as specified in JIS B 0951. The joint structure 1 is manufactured in the same manner as in Example 1 of the present invention.

[0106] For the joint portion 10 of the obtained joint structure 1, similar to Example 1 of the present invention, a welding recess 25 is formed on the surface 22a of the plate portion 22 of the first resin plate 21, and a grid-like uneven shape is formed on its bottom surface 26. Furthermore, the longitudinal and transverse dimensions of the bottom surface 26 of the welding recess 25 are approximately the same as the dimensions of the front end portion 51 of the welding head 5. That is, the width w of the bottom surface 26 of the welding recess 25 along the thickness direction of the second resin plate 23 is approximately 1.6 mm.

[0107] Furthermore, in the obtained joint structure 1, the minimum thickness t3 of the joint portion 10, measured from the position of the welding recess 25 and independent of the measurement direction, was measured to be 0.75 mm. Additionally, the minimum thickness t4 of the first resin along the thickness direction of the first resin plate 21, measured at the deepest position on the bottom surface 26 of the welding recess 25, was also measured to be 0.75 mm.

[0108] For the obtained joint structure 1, the joint strength was measured using the same measurement method as in Example 1 of the present invention, and the joint strength was measured to be 123 [N].

[0109] [Example 4 of the present invention]

[0110] As a welding joint, such as Figure 8 As shown in (b), a welding head 5G with a cross-sectional area of ​​2.0 mm in length and 8.0 mm in width and a peak-shaped protrusion of 0.5 mm at the front end 51G, and a concave-convex surface formed by sandblasting on the front end face of the protrusion, is used to manufacture the joint structure 1 in the same manner as in Example 1 of the present invention.

[0111] For the joint portion 10 of the obtained joint structure 1, similar to Example 1 of the present invention, a welding recess 25 is formed on the surface 22a of the plate surface 22 of the first resin plate 21, and a peak-shaped convex protrusion of the welding head 5 is directly transferred onto its bottom surface 26. In addition, the size and shape of the bottom surface 26 of the welding recess 25 are approximately the same as the size and shape of the front end portion 51 of the welding head 5. That is, the width w of the bottom surface 26 of the welding recess 25 along the thickness direction of the second resin plate 23 is approximately 2.0 mm.

[0112] Furthermore, in the obtained joint structure 1, the minimum thickness t3 of the joint portion 10, measured from the position of the welding recess 25 and independent of the measurement direction, was measured to be 1.00 mm. Additionally, the minimum thickness t4 of the first resin along the thickness direction of the first resin plate 21, measured at the deepest position on the bottom surface 26 of the welding recess 25, was measured to be 0.75 mm.

[0113] For the obtained joint structure 1, the joint strength was measured using the same measurement method as in Example 1 of the present invention, and the joint strength was measured to be 135 [N].

[0114] [Example 5 of the present invention]

[0115] As a welding joint, such as Figure 8 As shown in (c), a welding head 5H with a cross-sectional area of ​​2.0 mm in length and 8.0 mm in width and a peak-shaped protrusion at the front end 51H, a rounded corner with a radius of 1.0 mm at the front end of the protrusion, and a convex surface with a protrusion height of 0.5 mm is used to manufacture the joint structure 1 in the same manner as in Example 1 of the present invention.

[0116] For the joint portion 10 of the obtained joint structure 1, similar to Example 1 of the present invention, a welding recess 25 is formed on the surface 22a of the plate portion 22 of the first resin plate 21, and the shape of the peak-shaped protrusion of the welding head 5 is directly transferred onto its bottom surface 26. In addition, the size and shape of the bottom surface 26 of the welding recess 25 are approximately the same as the size and shape of the front end portion 51 of the welding head 5. That is, the width w of the bottom surface 26 of the welding recess 25 along the thickness direction of the second resin plate 23 is approximately 2.0 mm.

[0117] Furthermore, in the obtained joint structure 1, the minimum thickness t3 of the joint 10, measured from the position of the welding recess 25 and independent of the measurement direction, was measured to be 0.90 mm. Additionally, the minimum thickness t4 of the first resin, measured at the deepest position on the bottom surface 26 of the welding recess 25 along the thickness direction of the first resin plate 21, was measured to be 0.75 mm.

[0118] The joint strength of the obtained joint structure 1 was measured using the same measurement method as in Example 1 of the present invention, and the joint strength was measured to be 146 [N].

[0119] [Example 6 of the present invention]

[0120] Except that the pressing depth of the welding head 5 when forming the joint 10 is set to 1.45 mm, the joint structure 1 was manufactured in the same manner as in Example 1 of the present invention.

[0121] The joint portion 10 of the obtained joint structure 1 has a welding recess 25 formed on the surface 22a of the plate surface 22 of the first resin plate 21, and a grid-like uneven shape formed on its bottom surface 26. Furthermore, the longitudinal and transverse dimensions of the bottom surface 26 of the welding recess 25 are approximately the same as the dimensions of the front end portion 51 of the welding head 5. That is, the width w of the bottom surface 26 of the welding recess 25 along the thickness direction of the second resin plate 23 is approximately 2.4 mm.

[0122] Furthermore, in the obtained joint structure 1, the minimum thickness t3 of the joint 10, measured from the position of the welding recess 25 and independent of the measurement direction, was measured to be 0.05 mm. Additionally, the front end position of the end face 24 of the second resin is located approximately at the same position as the plate face 22 of the first resin plate 21 before the joint 10 is formed, and the minimum thickness t4 of the first resin, measured at the position of the deepest bottom surface 26 in the welding recess 25 and along the thickness direction of the first resin plate 21, was measured to be 0.05 mm.

[0123] For the obtained joint structure 1, the joint strength was measured using the same measurement method as in Example 1 of the present invention, and the joint strength was measured to be 70 [N].

[0124] [Example 7 of the present invention]

[0125] The thickness t1 of the first resin plate 21 is set to 3.0 mm, the thickness t2 of the second resin plate 23 is set to 1.5 mm, and the pressing depth of the welding head 5 when forming the joint 10 is set to 0.90 mm. Otherwise, the joint structure 1 is manufactured in the same manner as in Example 1 of the present invention.

[0126] The joint portion 10 of the obtained joint structure 1 has a welding recess 25 formed on the surface 22a of the plate surface 22 of the first resin plate 21, and a grid-like uneven shape is formed on its bottom surface 26. In addition, the longitudinal and transverse dimensions of the bottom surface 26 of the welding recess 25 are approximately the same as the dimensions of the front end portion 51 of the welding head 5. That is, the width w of the bottom surface 26 of the welding recess 25 along the thickness direction of the second resin plate 23 is approximately 2.4 mm.

[0127] Furthermore, in the obtained joint structure 1, the minimum thickness t3 of the joint 10, measured from the position of the welding recess 25 and independent of the measurement direction, was measured to be 2.10 mm. Additionally, the front end position of the end face 24 of the second resin is located approximately at the same position as the plate face 22 of the first resin plate 21 before the joint 10 is formed, and the minimum thickness t4 of the first resin along the thickness direction of the first resin plate 21, measured at the position of the deepest bottom surface 26 in the welding recess 25, was measured to be 2.10 mm.

[0128] For the obtained joint structure 1, the joint strength was measured using the same measurement method as in Example 1 of the present invention, and the joint strength was measured to be 12 [N].

[0129] [Comparative Example 1]

[0130] As a comparative example 1, a joining structure as described in FIG. 11 of the aforementioned Patent Document 2 was formed. A through hole is provided on the first resin plate 21, and a protrusion is provided at the front end of the end face 24 of the second resin plate 23. The protrusion has a wide head forming the front end and a narrow body portion connecting the head to the mating surface of the first resin plate 21. Next, the wider portion of the head in the protrusion is inserted into the through hole of the plate face 22 of the first resin plate 21 from the back side in a bent state, in the order of head and body portion, and the end face 24 of the second resin plate 23 is aligned at a right angle. Then, the two ends of the head are restored to their state before bending, and the protrusion is inserted into the through hole so that the body portion passes through the through hole, thus forming a joining structure.

[0131] In Comparative Example 1, more resin plates were required than in the present invention example in order to provide a protrusion at the front end of the end face 24 of the second resin plate 23. The joint strength of the obtained joint structure was measured using the same measurement method as in Example 1 of the present invention, and the measured joint strength was a maximum of 93 [N].

[0132] [Comparative Example 2]

[0133] In Comparative Example 2, a hole is provided on the first resin plate 21, and a protrusion is provided at the front end of the end face 24 of the second resin plate 23. Next, the protrusion of the end face 24 of the second resin plate 23 is inserted from the back side into the hole of the surface face 22 of the first resin plate 21, aligning the end face 24 of the second resin plate 23 at a right angle. Then, the protrusion of the end face 24 of the second resin plate 23 protruding from the hole of the surface face 22 of the first resin plate 21 is fused together by heat fusion, thereby fixing the end face 24 of the second resin plate 23 and the surface face 22 of the first resin plate 21.

[0134] In Comparative Example 2, more resin plates were required than in the present invention example in order to provide a protrusion at the front end of the end face 24 of the second resin plate 23. The joint strength of the obtained joint structure was measured using the same measurement method as in Example 1 of the present invention, and the joint strength was measured to be a maximum of 120 [N].

[0135] As can be seen from the above, the joining structure 1 of Examples 1 to 7 of the present invention does not require a protrusion at the front end of the end face 24 of the second resin plate 23. Therefore, it is not necessary to provide too much resin plate for joining. In addition, all of them have a joining strength of more than 10 [N]. Moreover, since welding can be performed simply by oscillating ultrasonic waves U from the welding head 5, the operability of joining the first resin plate 21 and the second resin plate 23 is also excellent.

[0136] Therefore, the joining structure 1 of Examples 1 to 7 of the present invention can join resin plates together even without providing too many resin plates for joining, and the operability when joining resin plates is also excellent.

[0137] In particular, when the minimum thickness t4 of the first resin along the thickness direction of the first resin plate 21 is within the range of 0.1 mm to 2.0 mm when measured at the bottom surface of the welding recess 25, the bonding strength of the bonding structure 1 in Examples 1 to 5 of the present invention exceeds 120 [N], thus exhibiting high bonding strength and firmly bonding the resin plates together. Therefore, from the viewpoint of improving bonding strength, in particular, and achieving a firm bonding of the resin plates together even in parts where an excessive number of resin plates are not provided for bonding, it is considered preferable to set the minimum thickness t4 of the first resin along the thickness direction of the first resin plate 21 when measured at the bottom surface of the welding recess 25 to the range of 0.1 mm to 2.0 mm.

[0138] On the other hand, the joining structures of Comparative Examples 1 and 2 require a protrusion at the front end of the end face 24 of the second resin plate 23 in order to join the first resin plate 21 and the second resin plate 23, which requires more resin plates.

[0139] Explanation of reference numerals in the attached figures

[0140] 1. 1A~1F Joint Structure

[0141] 10, 10A~10F Joint

[0142] 10a Internal corner of the back side of the joint

[0143] 21, 21A~21D First Resin Board

[0144] 22. The surface of the first resin board

[0145] 22a The surface area of ​​the first resin board.

[0146] 22b The front (back) side of the first resin board.

[0147] 23 Second Resin Board

[0148] 24 End face of the second resin plate

[0149] 25, 25A~25F Welding recesses

[0150] 26, 26A~26F Bottom surface of the welding recess

[0151] 27, 27E, 27F weld overlay sections

[0152] 3. Wiring bundle with external casing

[0153] 30. Cable casing

[0154] 30a~30c Bending section

[0155] 31 Wall section

[0156] 32 Containment Department

[0157] 4. Electrical wires

[0158] 40 Wiring bundle

[0159] 5. 5G, 5H welding joints

[0160] The front end of the 51, 51G, and 51H welding joints

[0161] t1 Thickness of the first resin board

[0162] t2 Thickness of the second resin board

[0163] t3 Minimum thickness of the first resin plate when measured from the weld recess position.

[0164] t4 The minimum thickness of the first resin when measured at the bottom surface of the weld recess.

[0165] U Ultrasonic

[0166] X1 Second resin board thickness direction

[0167] X2 Direction of wire extension

Claims

1. A joining structure having a joint formed by welding a surface portion of a first resin plate formed of a first resin with an end portion of a second resin plate formed of a second resin in a mating state, wherein, The first resin is a foaming resin. The second resin is either a non-foaming resin or a foaming resin. The joint has a welding recess on the surface and an overlay portion formed by the melting and solidification of at least the first resin and the second resin at the inner corner of the back side.

2. The bonded structure of Claim 1, wherein, When the thickness of the first resin is measured at the bottom surface of the welding recess in the joint, the minimum thickness is in the range of 0.1 mm to 2.0 mm.

3. The bonded structure of Claim 1 or 2, wherein, When measured from the location of the welded recess, the minimum thickness of the joint is 0.1 mm or more.

4. The bonded structure of Claim 1 or 2, wherein, The angle between the face of the first resin board and the end face of the second resin board, when measured on the acute angle side, is within the range of 45° to 90°.

5. The joining structure as claimed in claim 3, wherein, The angle between the face of the first resin board and the end face of the second resin board, when measured on the acute angle side, is within the range of 45° to 90°.

6. The joining structure as described in claim 1, 2, or 5, wherein, One or both of the first resin and the second resin contain polypropylene resin.

7. The joining structure as claimed in claim 3, wherein, One or both of the first resin and the second resin contain polypropylene resin.

8. The joining structure as claimed in claim 4, wherein, One or both of the first resin and the second resin contain polypropylene resin.

9. An outer casing for an electrical wire, which is an outer casing for an electrical wire installed on the outer periphery of an electrical wire, wherein, The outer casing for the wire has a joint structure as described in any one of claims 1 to 8.

10. A wiring harness with an outer casing, comprising the wiring harness and the outer casing for the wire as described in claim 9. The wires are mounted on the outer periphery of the wiring bundle using an outer casing.

11. A method for manufacturing a joint structure, comprising: In the positioning process, the end face of the second resin plate formed of the second resin is positioned and held in a state that aligns with the back face of the first resin plate formed of the first resin. In the welding head pressing process, with the surface of the first resin board and the end face of the second resin board aligned, the front end of the welding head is pressed against the surface of the first resin board. In the joint formation process, ultrasonic waves are emitted from the welding head, and welding is performed while the surface of the first resin plate and the end face of the second resin plate are aligned to form a joint. The first resin is a foaming resin. The second resin is either a non-foaming resin or a foaming resin. The joint has a welding recess on the surface and an overlay portion formed by the melting and solidification of at least the first resin and the second resin at the inner corner of the back side.

12. The method for manufacturing the joint structure as described in claim 11, wherein, The front end of the welding head is formed into a convex protrusion.

13. The method for manufacturing the joint structure as described in claim 11 or 12, wherein, At least a portion of the surface of the front end of the welding head is formed as a curved surface.

14. The method for manufacturing the joint structure as described in claim 11 or 12, wherein, At least a portion of the surface of the front end of the welding head is formed by a plurality of irregularities.

15. The method for manufacturing the joint structure as described in claim 13, wherein, At least a portion of the surface of the front end of the welding head is formed by a plurality of irregularities.

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