Member joint structure and method for manufacturing the same

Abstract

To provide a member joint structure increased in strength and a method for manufacturing the same.SOLUTION: A member joint structure 10 is formed by joining a plurality of kinds of members which are first and second rod-like bodies 12 and 14. A recess 16 is formed in the first rod-like body 12. The recess 16 is formed from the outer periphery of the first rod-like body 12 toward the center axis of the first rod-like body 12. The shape of the recess 16 is similar to that of the end of the second rod-like body 14. The end of the second rod-like body 14 enters the recess 16. A part from the outer periphery in the first rod-like body 12 to the bottom of the recess 16 and the end of the second rod-like body 14 are joined to form a joined part 18.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a member joining structure in which a plurality of metal members are joined together, and a method for manufacturing the same. [Background technology]

[0002] Aircraft obstruction lights are installed on structures that obstruct aircraft navigation. A protective net (protective frame) is installed to protect the aircraft obstruction lights from lightning. Paragraph 0009 of Patent Document 1 describes that the protective net of the aircraft obstruction lights is made of aluminum rods fixed together by welding.

[0003] However, obstacle lights are often installed at high altitudes and are subject to strong winds. Strong winds can cause the protective net to vibrate, causing the rods that make up the net to come loose. This has led to a demand for a component joint structure that can increase the joint strength between the rods. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2005-117874 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a member joining structure with increased strength and a method for manufacturing the same. [Means for solving the problem]

[0006] The component joining structure of the present invention comprises a first rod-shaped body made of metal, a recess formed in the first rod-shaped body, a second rod-shaped body made of metal and having its end inserted into the recess, and a joint where the portion from the outer periphery of the first rod-shaped body to the bottom of the recess and the end of the second rod-shaped body are kneaded together to join the first rod-shaped body and the second rod-shaped body.

[0007] The manufacturing method of the present invention includes the steps of preparing a first rod-shaped body and a second rod-shaped body made of metal, forming a recess from the outer periphery of the first rod-shaped body toward the central axis of the first rod-shaped body, inserting the end of the second rod-shaped body into the recess and bringing the bottom of the recess into contact with the end of the second rod-shaped body, and rotating and pressing a friction stir welding tool from the outer periphery of the first rod-shaped body toward the bottom of the recess, thereby joining the bottom of the recess and the end of the second rod-shaped body by friction stir welding. [Effects of the Invention]

[0008] According to the present invention, two rod-shaped bodies are joined by friction stir welding, resulting in the two rod-shaped bodies being integrated. This provides higher joining strength than conventional welding. When this member joining structure is used in a protective net for an aircraft obstruction light, it can reduce the probability of the rod-shaped bodies coming apart due to strong winds. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a cross-sectional view of a member joining structure. [Figure 2] FIG. 10 is a cross-sectional view of a first rod-shaped body having recesses formed therein. [Figure 3] FIG. 2 is a cross-sectional view of a first rod-shaped body with a plane formed on the outer periphery thereof. [Figure 4] FIG. 10 is a cross-sectional view showing the end of a second rod-shaped body inserted into a recess of a first rod-shaped body. [Figure 5] FIG. 10 is a cross-sectional view of a first rod-shaped body before a tool is pressed against the first rod-shaped body from the outside. [Figure 6] FIG. 10 is a cross-sectional view of the tool being pressed to form a joint. [Figure 7] FIG. 1 is a perspective view of a protective net placed around an aviation obstruction light. [Figure 8] 1A and 1B are diagrams showing a first rod-shaped body joined to a base plate, where (a) is a cross-sectional view showing the end of the first rod-shaped body inserted into a recess in the base plate, and (b) is a cross-sectional view showing the weld formed by friction stir welding. [Figure 9] FIG. 10 is a cross-sectional view of the first rod-shaped body before a tool is pressed against the outside of the first rod-shaped body without forming a flat surface on the first rod-shaped body. DETAILED DESCRIPTION OF THE INVENTION

[0010] The member joining structure and the manufacturing method thereof according to the present invention will be described with reference to the drawings, which are schematic diagrams.

[0011] [Embodiment 1] The member joint structure 10 of the present invention is a structure in which a plurality of types of members are joined together. In this description, the plurality of types of members are a first rod-shaped body 12 and a second rod-shaped body 14.

[0012] The first rod-shaped body 12 and the second rod-shaped body 14 are linear rod-shaped bodies. The material of each rod-shaped body 12, 14 is a metal such as aluminum, copper, iron, brass, or an alloy thereof. The first rod-shaped body 12 and the second rod-shaped body 14 are cylindrical, prism-shaped, or the like, but their shapes are not limited thereto. The first rod-shaped body 12 and the second rod-shaped body 14 shown in the figure are cylindrical. Since the second rod-shaped body 14 is inserted into the first rod-shaped body 12, the cross-sectional diameter of the first rod-shaped body 12 is larger than the cross-sectional diameter of the second rod-shaped body 14.

[0013] The angle formed by the central axis of the first rod-shaped body 12 and the central axis of the second rod-shaped body 14 is 90 degrees. When the first rod-shaped body 12 is oriented vertically, the second rod-shaped body 14 is oriented horizontally.

[0014] A recess 16 is formed in the first rod-shaped body 12. The recess 16 is formed from the outer periphery of the first rod-shaped body 12 toward the central axis of the first rod-shaped body 12. The shape of the recess 16 is the same as the shape of the end of the second rod-shaped body 14. The end of the second rod-shaped body 14 fits into the recess 16.

[0015] A joint 18 is formed by joining the portion of the first rod-shaped body 12 from the outer periphery to the bottom of the recess 16 to the end of the second rod-shaped body 14. The joint 18 includes an exposed portion 20 that is exposed from the outer periphery of the first rod-shaped body 12. The joint 18 is formed so as to include a portion where the central axis of the second rod-shaped body 14 extends into the first rod-shaped body 12. The joint 18 is formed by friction stir welding, and the first metal rod 12 and the second metal rod 14 are kneaded and solidified. The first rod-shaped body 12 and the second rod-shaped body 14 are integrated by friction stir welding.

[0016] When the first rod-shaped body 12 is cylindrical, as described below, friction stir welding may be performed after forming a flat surface. In this case, the outer periphery of the first rod-shaped body 12 and the exposed portion 20 of the joint 18 have different shapes. This difference in shape may result in a step that is recessed from the outer periphery of the first rod-shaped body 12 to the exposed portion 20. The step may not be uniform, and there may be a portion where there is no step between the outer periphery of the first rod-shaped body 12 and the exposed portion 20. The exposed portion 20 may have a flat portion, or may have traces of mixing caused by friction stir welding.

[0017] The manufacturing method of the member joint structure 10 will be described below. (1) Prepare a first rod-shaped body 12 and a second rod-shaped body 14. The first rod-shaped body 12 and the second rod-shaped body 14 are cylindrical metal rods made of aluminum, copper, or the like as described above.

[0018] (2) Using a drill or the like, form a recess 16 from the outer periphery of the first rod-shaped body 12 toward the central axis (FIG. 2). The rotation axis of the drill should be perpendicular to the central axis of the first rod-shaped body 12. The bottom of the recess 16 should be at or near the central axis of the first rod-shaped body 12. The bottom of the recess 16 does not need to be completely flat.

[0019] (3) If the first rod-shaped body 12 is a cylinder or the like, its outer periphery is curved. A flat surface 22 may be formed on the outer periphery of the first rod-shaped body 12 (FIG. 3). The flat surface 22 is the portion against which the tool for friction stir welding is pressed. The flat surface 22 is circular in shape and is the same size as or slightly larger than the portion against which the tool for friction stir welding is pressed. The flat surface 22 is the portion through which the central axis of the second rod-shaped body 14 passes when the second rod-shaped body 14 is inserted into the recess 16. The flat surface 22 may be formed so as to be parallel to the bottom of the recess 16. The flat surface 22 is formed by an end mill or the like.

[0020] Note that steps (2) and (3) may be performed in any order, or may be performed simultaneously. The order may be changed as appropriate, as long as step (2) is completed before inserting the second rod-shaped body 14 into the recess 16, and step (3) is completed before performing friction stir welding.

[0021] When the flat surface 22 is formed, the first rod-shaped body 12 is not limited to being cylindrical, and when the outer periphery of the first rod-shaped body 12 is curved, the flat surface 22 may be formed on the curved surface. Even when the first rod-shaped body 12 has a shape with corners, such as a rectangular column, a flat surface may be formed on the corner if it is necessary to press a tool for friction stir welding against the corner.

[0022] (4) The end of the second rod-shaped body 14 is inserted into the recess 16 (FIG. 4). The central axis of the first rod-shaped body 12 and the central axis of the second rod-shaped body 14 are aligned perpendicularly. The bottom of the recess 16 and the end of the second rod-shaped body 14 are brought into contact. If the shapes of the bottom of the recess 16 and the end of the second rod-shaped body 14 do not match, the bottom of the recess 16 and a portion of the second rod-shaped body 14 may be in contact. Even if the bottom of the recess 16 and the end of the second rod-shaped body 14 are not in contact, the first rod-shaped body 12 will melt first, as described below, and the end of the second rod-shaped body 14 will come into contact with the bottom of the recess 16 when the second rod-shaped body 14 melts. Therefore, it is preferable to insert the end of the second rod-shaped body 14 deepest into the recess 16.

[0023] (5) A friction stir welding tool 24 is rotated from the outside of the first rod-shaped body 12 toward the bottom of the recess 16 ( FIG. 5 ), and a load is applied to press the first rod-shaped body 12 against the bottom. The rotation axis L1 of the tool 24 preferably coincides with an extension line L2 of the central axis of the second rod-shaped body 14. The extension line L2 is a linear extension of the central axis of the second rod-shaped body 14. The rotation axis L1 of the tool 24 is aligned with the extension line L2 of the central axis of the second rod-shaped body 14, and the tool 24 is moved toward the bottom of the recess 16. When the tool 24 comes into contact with the first rod-shaped body 12, the first rod-shaped body 12 softens, and when the tool 24 comes into contact with the second rod-shaped body 14, the second rod-shaped body 14 also softens. Frictional heat is generated at the bottom of the recess 16 in the first metal rod 12 and at the end of the second rod-shaped body 14, causing softening, and the rotation of the tool 24 causes plastic flow and mixing. The bottom of the recess 16 and the end of the second rod-shaped body 14 are friction stir welded together, forming a welded portion 18 (FIG. 6).

[0024] The rotation axis L1 of the tool 24 and the extension line L2 of the central axis of the second rod-shaped body 14 do not necessarily have to be perfectly aligned, and may be slightly misaligned. It is sufficient that the extension line L2 of the central axis of the second rod-shaped body 14 overlaps with the tool 24. The shape of the welded portion 18 shown in the figure is an example, and the shape of the welded portion 18 may be slightly different. As long as the first rod-shaped body 12 and the second rod-shaped body 14 are integrated by friction stir welding, the shape of the welded portion 18 may be slightly different from that shown in the figure.

[0025] (6) The tool 24 is removed from the joint 18 to complete the joining (FIG. 1). Because friction stir welding has been performed from the outer periphery of the first rod-shaped body 12 to the end of the second rod-shaped body 14, an exposed portion 20 of the joint 18 is formed so as to be exposed from the outer periphery of the first rod-shaped body 12.

[0026] As described above, the two rod-shaped bodies 12 and 14 are joined by friction stir welding, facing perpendicular to each other. Unlike welding or screwing the first rod-shaped body 12 and the second rod-shaped body 14, the present invention integrates the two rod-shaped bodies 12 and 14, thereby firmly joining the two rod-shaped bodies 12 and 14.

[0027] [Embodiment 2] The number of first rod-shaped bodies 12 and second rod-shaped bodies 14 is not limited to one, and may be multiple. For example, as in the protective net (protective frame) 30 of an aviation obstruction light shown in FIG. 7, there may be four first rod-shaped bodies 12 and eight second rod-shaped bodies 14. The central axes of the multiple first rod-shaped bodies 12 are parallel to each other, and the first rod-shaped bodies 12 are arranged at the corners of a quadrangle. Two second rod-shaped bodies 14 join two other first rod-shaped bodies 12. The central axes of the first rod-shaped bodies 12 and the second rod-shaped bodies 14 are perpendicular to each other. The end of the second rod-shaped body 14 is inserted into the recess 16 of the first rod-shaped body 12, and the first rod-shaped body 12 and the second rod-shaped body 14 are joined to each other by friction stir welding.

[0028] The end of the first rod-shaped body 12 is attached to a base plate 32. The base plate 32 is a plate-shaped body made of a metal such as aluminum. An aviation obstruction light (not shown) is attached to the center of the base plate 32. As described above, the first rod-shaped body 12 and the second rod-shaped body 14 are firmly joined together. Compared to protective nets manufactured by conventional welding, this is less likely to be damaged by strong winds. It has been confirmed that when the first rod-shaped body 12 and the second rod-shaped body 14 are both made of aluminum cylinders, and the first rod-shaped body 12 has a diameter of 2 cm and the second rod-shaped body 14 has a diameter of 1 cm, the two rod-shaped bodies 12 and 14 will not come loose even when a load of approximately 2 tons is applied.

[0029] It is also possible to friction stir weld the base plate 32 of the protective net 30 and the first rod-shaped body 12. The base plate 32 is made of a metal such as aluminum or copper. The end of the first rod-shaped body 12 may be placed in contact with the base plate 32, and a friction stir welding tool 22 may be pressed from the base plate 32 toward the end of the first rod-shaped body 12 to knead and solidify the base plate 32 and the end of the first rod-shaped body 12. A recess 34 may be formed in the base plate 32 (FIG. 8(a)), and the end of the first rod-shaped body 12 may be inserted therein. Then, friction stir welding may be performed in this state to form a weld 36 (FIG. 8(b)).

[0030] 7, the first rods 12 are arranged at the corners of a rectangle, but they may be arranged at the corners of other polygons. The number of second rods 14 arranged between the first rods 12 is also not limited to two and may be other numbers. The number and arrangement of the first rods 12 and second rods 14 may be changed as appropriate to match the shape and size of the aviation obstruction light.

[0031] [Embodiment 3] As long as the end of the second rod-shaped body 14 can be inserted into the recess 16 of the first rod-shaped body 12, other structures are not limited. The cross section of the portion of the second rod-shaped body 14 that fits into the recess 16 may be different from that of the other portion. The strength of the second rod-shaped body 14 may be increased by thickening the portion of the second rod-shaped body 14 that does not fit into the recess 16.

[0032] The first rod-shaped body 12 and the second rod-shaped body 14 are not limited to being straight, and each of the rod-shaped bodies 12 and 14 may be bent or curved at any position.

[0033] Although the central axes of the first rod-shaped body 12 and the second rod-shaped body 14 are perpendicular to each other in the above embodiment, this is not limited to a perpendicular direction. Depending on the method of forming the recess 16, the angle of the central axis of the second rod-shaped body 14 relative to the central axis of the first rod-shaped body 12 may be changed as appropriate. Furthermore, the same applies when there are multiple first rod-shaped bodies 12, multiple second rod-shaped bodies 14, or both. The central axes of the multiple first rod-shaped bodies 12 are not necessarily parallel to each other. Similarly, the central axes of the multiple second rod-shaped bodies 14 are not necessarily parallel to each other.

[0034] By forming the flat surface 22 on the outer periphery of the first rod-shaped body 12, a difference in shape occurs between the first rod-shaped body 12 and the exposed portion 20, forming a step. The difference in shape may be eliminated by filling the exposed portion 20 with metal to the extent that the flat surface 22 is formed. Alternatively, the difference in shape between the first rod-shaped body 12 and the exposed portion 20 may be eliminated by cutting, polishing, grinding, etc. the first rod-shaped body 12 down to the exposed portion 20.

[0035] [Embodiment 4] The melting points of the first rod-shaped body 12 and the second rod-shaped body 14 may be different. For example, the first rod-shaped body 12 may be made of aluminum or an aluminum alloy, and the second rod-shaped body 14 may be made of copper or a copper alloy. The melting point of aluminum is approximately 660°C, and the melting point of copper is approximately 1085°C. When the first rod-shaped body 12 is melted by friction stir welding, the heat of the first rod-shaped body 12 is conducted to the second rod-shaped body 14, making it easier for the second rod-shaped body 14 to melt.

[0036] [Embodiment 5] Although friction stir welding was performed after forming the flat surface 22 on the outer periphery of the first rod-shaped body 12, friction stir welding may also be performed without forming the flat surface 22 (FIG. 9). If the first rod-shaped body 12 originally has a flat surface on its outer periphery, the tool 24 may be pressed against that flat surface.

[0037] [Embodiment 6] The melting point of the first rod-shaped body 12 may be higher than the melting point of the second rod-shaped body 14. For example, the first rod-shaped body 12 may be copper or a copper alloy, and the second rod-shaped body 14 may be aluminum or an aluminum alloy. The melting points of the first rod-shaped body 12 and the second rod-shaped body 14 may be selected appropriately depending on the characteristics of the tool 24 used to perform friction stir welding, etc.

[0038] In addition, the present invention can be implemented in various forms with various improvements, modifications, and changes made based on the knowledge of those skilled in the art without departing from the spirit of the present invention. [Explanation of symbols]

[0039] 10: Component joint structure 12: First rod-shaped body 14:Second rod-shaped body 16, 34: Recess 18, 36: Joint 20: Exposed part of joint 22: A plane formed on the outer periphery of the first rod-shaped body 24: Tools for friction stir welding 30: Protective netting placed around aviation obstruction lights 32: Base plate

Claims

1. a first rod-shaped body formed of metal; a recess formed in the first rod-shaped body; a second rod-shaped body made of metal and having an end inserted into the recess; a joint portion where the portion from the outer periphery of the first rod-shaped body to the bottom of the recess and the end portion of the second rod-shaped body are kneaded together to join the first rod-shaped body and the second rod-shaped body; A component joining structure equipped with the above.

2. 2. The member joining structure according to claim 1, wherein the outer periphery of the first rod-shaped body and the exposed portion of the joining portion have different shapes.

3. 2. The member joining structure according to claim 1, wherein the first rod-shaped members are plural in number, and the second rod-shaped members are disposed between the first rod-shaped members.

4. 2. The member joining structure according to claim 1, further comprising a base plate made of a metal plate, the base plate and the end of the first rod being joined by kneading the base plate and the end of the first rod.

5. providing a first rod-shaped body and a second rod-shaped body formed of metal; forming a recess from the outer periphery of the first rod-shaped body toward the central axis of the first rod-shaped body; inserting an end of a second rod-shaped body into the recess; a step of pressing a friction stir welding tool from the outer periphery of the first rod-shaped body toward the bottom of the recess while rotating, and joining the bottom of the recess and the end of the second rod-shaped body by friction stir welding; A manufacturing method of a member joining structure comprising:

6. 6. The method for manufacturing a member welding structure according to claim 5, further comprising the step of forming a flat surface on an outer periphery of the first rod-shaped body before performing the friction stir welding.

7. 6. The method for manufacturing a member joint structure according to claim 5, wherein the first rod-shaped bodies are plural in number, and the second rod-shaped bodies are disposed between two of the first rod-shaped bodies.

8. 6. The method for manufacturing a member joining structure according to claim 5, further comprising a step of friction stir welding an end of the first rod-shaped body to a base plate made of a metal plate.

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