KR102578674B1 - Method for manufacturing a metal structure - Google Patents

Abstract

[Problem to be solved] To provide a method of manufacturing a metal structure that can efficiently form a sealed space with excellent sealing properties and improve the degree of freedom in designing the sealed space.
[Solution] A method of manufacturing a metal structure having at least one sealed space therein, the manufacturing method comprising: a preparation process for two metal members, an assembly process for the two metal members, and at least one seal between the two metal members. A sealing process of forming a joint for joining two metal members along the movement path of the tool so that a sealing space of It is characterized by comprising an expansion process of moving the tool to form the joint to expand the longitudinal joint being formed.

Description

Method for manufacturing a metal structure {METHOD FOR MANUFACTURING A METAL STRUCTURE}

The present invention relates to a method of manufacturing a metal structure.

As a conventional metal structure, there is a metal structure including a main body portion and a cover portion. A cover groove is formed in the main body portion. A concave groove is further formed on the bottom surface of the cover groove of the main body. The cover portion is fitted into the cover groove. Around the cover groove, the main body part and the cover part are joined. Thereby, the space surrounded by the concave groove and the cover portion becomes a sealed space. The sealed space can be used as a flow path for fluid. Such a metal structure can be used as a metal structure for heat transfer. The metal structure for heat transfer is disposed, for example, in contact with or close to an object to be heat exchanged, heated or cooled. For example, when heat is emitted from an object, a cooling medium flows through the corresponding flow path and heat is transferred from the object to the metal body and the cooling medium.

Patent Document 1 discloses a technique for forming an internal space in a metal structure by joining the main body portion and the cover portion around the cover groove by friction stir welding. The internal space can be used as a sealed space.

Japanese Patent Publication No. 2014-240706

The purpose of the present invention is to provide a method for manufacturing a metal structure that can efficiently form a sealed space with excellent sealing properties and can improve the degree of freedom in designing the sealed space.

The present inventor studied the above-described problem and obtained the following findings.

Generally, in friction stir welding, when the joining operation by the tool is completed, the tool is pulled out from the surface (upper surface) of the material by moving upward in a rotated state. At this time, there are cases where a concave portion resulting from the extraction of the tool is formed at the extraction position. This concave portion is formed unexpectedly. The shape of the concave part is not constant. Therefore, when manufacturing a metal structure with a sealed space by friction stir welding, depending on the shape of the recess, there is a risk that the recess and the internal space may communicate. It is difficult to stably form a sealed space by this method.

For this problem, a method of moving the tool in the horizontal direction to the side of the assembly and pulling it out from the side of the assembly can be adopted. According to this method, since the tool is never pulled out from the surface (upper surface) of the material, no recess is formed. However, in order to extract the tool from the side of the assembly, the tool must move horizontally to the side while avoiding the sealed space. There is a need to secure a path for this. As a result, the layout of the sealed space in the metal structure is restricted. The degree of freedom in designing the sealed space is reduced. For example, in a metal structure for heat transfer, the shape of the sealed space is an important factor that affects the efficiency of heat exchange. Therefore, it is desirable to secure the design freedom of the sealed space. Additionally, if the tool path is long, the time required for manufacturing becomes longer, and manufacturing efficiency decreases.

Therefore, in order to efficiently form a sealed space with excellent sealing properties and also improve the design freedom of the sealed space, the tool must be installed to ensure sealing properties while keeping the movement of the tool for extraction as short as possible. How to pull it out upward becomes important.

The present invention is an invention completed based on the above-described knowledge, and the following configuration can be adopted.

(1) A method of manufacturing a metal structure having at least one sealed space therein, comprising:

The metal structure includes two metal members joined by friction stir welding while overlapping each other in the vertical direction, and the two metal members overlap each other in the vertical direction, thereby forming the two metal members. Configured to form an assembly having an internal space to be the at least one sealing space therebetween,

The manufacturing method is,

A preparation process of preparing the two metal members,

an assembly process of forming the assembly by overlapping the two metal members in the vertical direction;

The two metal members are inserted into the upper surface of the assembly while rotating the tool for friction stir welding, and the tool is moved so that the at least one sealing space is formed between the two metal members. A sealing process of forming a joint to be joined in the vertical direction along a movement path of the tool;

Before withdrawing the tool from its extraction position on the top surface of the assembly, an expansion process of moving the tool to form the joint to expand the longitudinal joint formed when the tool reaches the extraction position.

It is characterized by including.

According to the manufacturing method of (1), the joint is formed so that the longitudinal joint is expanded. The longitudinal joint extends outward in the radial direction of the longitudinal joint. Accordingly, even if a recess is formed at the extraction position by the tool being pulled upward from the extraction position, the joint portion can remain around the depression. The remaining joints can prevent or suppress communication between the exterior and interior of the metal structure (eg, sealed space) through the concave portion. Therefore, high sealing properties are obtained. Additionally, because this makes it possible to pull out the tool upward, it becomes unnecessary to secure a path for moving the tool to the side. Therefore, the degree of freedom in designing the sealed space can be improved.

As one embodiment, the following aspect can be adopted.

(2) As the manufacturing method of (1),

In the expansion process, the longitudinal joint is expanded by moving the tool so that the joint overlaps the entire outer edge of the longitudinal joint.

According to the manufacturing method (2), the longitudinal joint is expanded so that the joint overlaps around the entire outer circumference. Therefore, the recess and the internal space can be separated more reliably when removing the tool. Higher sealing properties can be obtained, and the degree of freedom in designing the sealed space can be further improved.

As one embodiment, the following aspect may be adopted.

(3) The manufacturing method of (1) or (2),

In the expansion step, the longitudinal joint portion is expanded by moving the tool to draw a ring surrounding the extraction position.

According to the manufacturing method (3), a sealed space with high sealability can be formed more efficiently, and the degree of freedom in designing the sealed space can be further improved.

As one embodiment, the following aspect may be adopted.

(4) The manufacturing method of any one of (1) to (3),

The manufacturing method is,

Characterized in that it includes an extraction process of moving the tool to the extraction position located inside the expanded end joint and extracting the tool from the extraction position.

According to the manufacturing method (4), higher sealing properties can be obtained, and the degree of freedom in designing the sealed space can be further improved.

As one embodiment, the following aspect may be adopted.

(5) The manufacturing method of any one of (1) to (4),

When the two metal members overlap each other in the vertical direction, the two metal members have portions that surface contact each other in the vertical direction,

In the expansion process, the tool passes through portions in surface contact with each other in the vertical direction.

In the manufacturing method of (5), when two metal members overlap each other in the vertical direction during the assembly process, the portions that surface contact each other in the vertical direction are aligned in the vertical direction with each other, for example, by gravity and/or a jig. Since they are in contact with each other, the occurrence of gaps can be suppressed or prevented. In the expansion process, the tool passes through portions that surface contact each other in the vertical direction. As a result, the expanded longitudinal joint includes portions that surface contact each other in the vertical direction. Therefore, the occurrence of voids in the extended end joint can be suppressed or prevented. Higher sealing properties can be obtained, and the degree of freedom in designing the sealed space can be further improved.

As one embodiment, the following aspect may be adopted.

(6) The manufacturing method of any one of (1) to (5),

In the expansion process, the tool moves so that the expanded end joint has a distance from the sealing space in plan view.

According to the manufacturing method of (6), the expanded longitudinal joint does not overlap the sealing space in plan view. By securing the distance between the end joint and the sealed space, higher sealing properties can be obtained and the degree of freedom in designing the sealed space can be further improved.

As one embodiment, the following aspect may be adopted.

(7) The manufacturing method of any one of (1) to (6),

The sealed space is configured to prevent fluid from entering and exiting between the inside and the outside.

According to the manufacturing method (7), high sealing properties can be obtained and the degree of freedom in designing the sealed space can be improved. It can effectively prevent fluid from entering and exiting the sealed space.

As one embodiment, the following aspect may be adopted.

(8) The manufacturing method of any one of (1) to (7),

The metal structure is a metal structure for heat transfer that is installed in contact with or close to an object to be heat exchanged, heated or cooled.

According to the manufacturing method (8), high sealing properties can be obtained and the degree of freedom in designing the sealed space can be improved. By using the sealed space as a fluid flow path, for example, a metal structure with densely arranged flow paths excellent in fluid sealing properties can be realized. In other words, a metal structure with excellent heat conductivity can be realized through high sealing properties. That is, according to the manufacturing method (8), a metal structure that is efficient and suitable for heat transfer can be manufactured.

According to the present invention, it is possible to efficiently form a sealed space with excellent sealing properties, and the degree of freedom in designing the sealed space can be improved.

[Figure 1] Figure 1(a) is a schematic cross-sectional view for explaining the preparation process, and Figure 1(b) is a schematic cross-sectional view for explaining the assembly process. (c) is a schematic cross-sectional view for explaining the sealing process.
[FIG. 2] Figures 2 (a) to (c) are schematic plan views for explaining the sealing process.
[FIG. 3] FIG. 3(a) is a plan view schematically showing the state when the tool reaches the extraction position in the sealing process, and FIG. 3(b) is a cross-sectional view thereof.
[FIG. 4] FIG. 4(a) is a plan view schematically showing the expansion process, and FIG. 4(b) is a cross-sectional view thereof.
[Figure 5] Figure 5(a) is a plan view schematically showing the expansion process, and Figure 5(b) is a cross-sectional view thereof.
[Figure 6] Figure 6(a) is a plan view schematically showing the extraction process, and Figure 6(b) is a cross-sectional view thereof.

The manufacturing method of the metal structure according to the embodiment will be described below. The metal structure according to the embodiment includes a cover portion 2 and a main body portion 1 as two metal members. The main body portion 1 and the cover portion 2 are examples of metal members. In the drawing, the vertical direction W is the direction in which two metal members (main body portion 1 and cover portion 2) overlap, the direction in which the two metal members are joined, and the vertical direction W in which the tool 5 is inserted. It's a direction. The width direction P corresponds to the width direction of the rectangular sealed space 3. The longitudinal direction Q corresponds to the longitudinal direction of the rectangular sealed space 3. The width direction P and the longitudinal direction Q are directions perpendicular to the vertical direction W, that is, the horizontal direction.

<Preparation process>

First, as shown in Fig. 1(a), in the preparation process, the main body portion 1 and the cover portion 2 are prepared.

The main body portion 1 is a rectangular plate-shaped body when viewed in cross section. The main body portion 1 is made of metal. The metal constituting the main body 1 is a metal material capable of plastic flow by being softened by the frictional heat of friction stirring. Examples of the metal include copper, aluminum, or an alloy containing at least one of these.

The main body portion 1 has a concave portion 1r on the upper surface 1u. The concave portion 1r has a rectangular space when viewed in cross section. The recessed portion 1r is configured to receive the cover portion 2 within the recessed portion 1r by fitting the cover portion 2 into it.

A sealed space 3 is formed in the bottom surface 1V of the concave portion 1r. Then, the sealed space 3 is sealed to be liquid-tight by joining the main body 1 and the cover 2. After the main body portion 1 and the cover portion 2 are joined, the metal structure supplies fluid to the sealed space 3 by connecting a fluid injection pipe or discharge pipe to a through hole 3a described later. It is structured as possible. Therefore, liquid-tight in this embodiment means liquid-tight except for the fluid inlet or outlet. Accordingly, at the inlet and outlet, fluid can enter and exit between the outside of the metal structure and the sealed space, but at locations other than the inlet or outlet, fluid cannot enter and exit between the outside of the metal structure and the sealed space.

The metal structure may or may not have an inlet and/or outlet connected to the sealed space. The metal structure may be used, for example, with pipes, etc. connected to the inlet and/or outlet. The metal structure may be used, for example, with a sealing member (stopper, etc.) installed at the inlet and/or outlet. The sealed space may be, for example, liquid-tight or air-tight. In FIG. 1(a), the space that becomes the sealed space 3 after joining is shown as the sealed space 3. The sealed space 3 is a rectangular space extending in the longitudinal direction Q.

The cover portion 2 is a rectangular plate-shaped body when viewed in cross section. The cover portion 2 is made of metal. The metal constituting the cover portion 2 is a metal material capable of plastic flow by being softened by the frictional heat of friction stirring. Examples of the metal include copper, aluminum, or an alloy containing at least one of these. The main body portion 1 and the cover portion 2 may be made of the same metal or may be made of different metals. The thickness of the cover portion 2 is equal to or substantially equal to the depth of the concave portion 1r.

<Assembly process>

In the assembly process, as shown in FIG. 1(b), the main body portion 1 and the cover portion 2 overlap in the vertical direction W. The cover portion 2 is mounted on the main body portion 1 so that the cover portion 2 is fitted into the concave portion 1r of the main body portion 1. Thereby, the assembly 10a having the sealed space 3 is formed. The assembly 10a includes two metal members (body portion 1 and cover portion 2) that are combined with each other and are not joined. The metal structure is made of, for example, at least two metal members (body portion 1 and cover portion 2) joined to each other so as to have at least one sealed space 3 therein.

At this time, a boundary 6 is formed between the upper surface 1u of the main body portion 1 and the upper surface 2u of the cover portion 2. Additionally, the bottom surface 2b of the cover portion 2 is in surface contact with the bottom surface 1V of the concave portion 1r in the vertical direction W. This part is “the part where the two face each other in the vertical direction” (11). The bottom surface 1V and the bottom surface 2b are parallel to the horizontal direction at least in the “portion where they surface contact each other in the vertical direction” 11.

Additionally, the concave portion 1r does not necessarily need to be formed. The assembly 10a is formed by mounting the plate-shaped cover portion 2 on the upper surface of the main body portion 1 where a space serving as the sealing space 3 is formed and where the concave portion 1r is not formed. It's okay. In this case as well, a portion is formed between the two metal members that are in vertical surface contact with each other.

<Sealing process>

The sealing process is performed on the assembly 10a, as shown in FIG. 1(c). In the sealing process, the main body portion 1 and the cover portion 2 are joined by friction stir welding. The tool 5 of a friction stirring device (not shown) is used in the sealing process. The tool 5 is made of a material with high heat resistance and wear resistance. The tool 5 is a cylindrical body having a sharp tip 5a at the tip. The tool 5 is controlled by a drive device included in the friction stirring device so that it moves while rotating.

As a device for friction stirring, a conventionally known device can be adopted. Specifically, while rotating, the tool 5 is capable of moving up and down relative to the main body 1 and the cover 2, and horizontal movement relative to the main body 1 and the cover 2. . The lifting movement is movement in the vertical direction W. Horizontal movement is, for example, movement in the width direction P or the longitudinal direction Q. At the distal end 5a of the tool 5, a spiral screw groove (not shown) is formed on the outer peripheral surface. Then, the assembly 10a is fixed so as not to move by a jig (not shown). The cover portion 2 is fixed to the main body portion 1 by a jig (not shown).

In the sealing process, the tool 5 is rotated and inserted into the upper surface of the assembly 10a. The insertion direction of the tool 5 is not particularly limited. Of the tools 5, for example, the tip portion 5a is inserted into the assembly 10a. When the tip 5a of the rotating tool 5 is inserted into the assembly 10a, as shown in FIG. 1(c), in addition to the area where the tip 5a is inserted, a joint is formed around that area as well. (7) is formed. Therefore, the depth of the joint portion 7 is greater than the depth at which the tip portion 5a is inserted. The width of the joint portion 7 is larger than the diameter of the tip portion 5a. The tip portion 5a is inserted so that the joint portion 7 reaches at least the bottom surface 1V.

The tip portion 5a is inserted so as to reach the bottom surface 1V. The depth of the joint portion 7 is greater than the thickness of the cover portion 2. The depth of the joint portion 7 is smaller than the sum of the thicknesses of the main body portion 1 and the cover portion 2. That is, the joint portion 7 reaches the bottom surface 1V, but does not penetrate the main body portion 1. As a result, a joint portion 7 is formed at the position where the tool 5 passes, so that the main body portion 1 and the cover portion 2 are joined.

Next, the operation of the tool 5 in the horizontal direction in the sealing process will be described with reference to FIGS. 2(a) to 2(c). First, each configuration when viewed from a plan view will be described. As shown in Fig. 2(a), the main body portion 1 has a rectangular shape in plan view. More specifically, the main body portion 1 has a rectangular shape with the vertical direction as the longitudinal direction in the drawing.

One recess 1r is formed in the upper surface 1u of the main body 1. The concave portion 1r is a long rectangle (oval shape) with rounded corners in the longitudinal direction Q than in the width direction P when viewed from the top. The cover portion 2 is also rectangular with rounded corners when viewed from the top. The cover portion 2 has a shape and size such that the cover portion 2 can be fitted into the concave portion 1r. By overlapping the main body portion 1 and the cover portion 2 in the vertical direction W, a portion 11 in surface contact with each other in the vertical direction W is formed to surround the entire outer edge of the sealed space 3. .

A plurality of through holes 3a are formed in the cover portion 2. The number of through holes 3a is, for example, 2. The through hole 3a can be used as an inlet or outlet for a fluid such as a refrigerant to the sealed space 3, which will be described later. The through hole 3a communicates with the exterior of the metal structure and the sealed space 3. The through hole may be formed on one of the two surfaces (upper surfaces 1u and 2u and the opposite surface) of the metal structure (assembly 10a) facing the vertical direction W, or on both surfaces. do. Through holes do not need to be formed.

It is preferable that through holes are not formed on surfaces where tools are not inserted (upper surfaces 1u and 2u). The sealability of the sealing space on the side where the tool is not inserted is maintained. Thereby, the main body portion 1 can be suitably used as a heat transfer surface that contacts or approaches the object to be heat exchanged, heated or cooled.

Figure 2(a) shows a state in which the tool 5 (not shown) is inserted into the insertion position 4 of the assembly 10a. The tool 5 is inserted into the assembly 10a from the position of the boundary 6. A joint portion 7 is formed at the position where the tool 5 is inserted. The tool 5 moves in the horizontal direction along the boundary 6 so as to surround the space that becomes the sealed space 3 . Figure 2(b) shows the assembly 10a when the tool 5 is moving along the boundary 6. Figure 2(c) shows the assembly 10a when the tool 5 reaches the extraction position 9. In FIG. 2(b) and FIG. 2(c), the thick arrow schematically represents the movement path of the tool 5.

The movement path when the tool 5 moves horizontally in the sealing process is a plane surrounding the space that becomes the sealing space 3, as shown, for example, in FIGS. 2(a) to 2(c). When viewed from, it contains an annular path. By forming the joint 7 along the corresponding movement path, the sealed space 3 can be formed. The movement path of the tool 5 in the sealing process includes an annular path in plan view surrounding the sealing space 3, for example between the insertion position 4 and the extraction position 9.

The movement path of the tool 5 passes around the entire outer edge of the sealed space 3 and the “portion in surface contact with each other in the vertical direction” 11. In “parts that surface contact each other in the vertical direction” (11), the occurrence of a gap in the vertical direction can be suppressed or prevented. The tool 5 moves so as to surround the entire outer periphery of the sealing space 3 while tracing the “portion that makes surface contact with each other in the vertical direction” 11. Around the entire outer edge of the sealed space 3, the “portions in surface contact with each other in the vertical direction” 11 are at least partially joined. As a result, among the "parts that surface contact each other in the vertical direction" (11), the part where two metal members (the main body part (1) and the cover part (2)) are joined in the vertical direction is outside the sealed space (3). Located all around the edge. Thereby, higher sealing properties are obtained.

FIG. 3(a) is a plan view schematically showing the state when the tool 5 reaches the extraction position 9, and FIG. 3(b) is a cross-sectional view thereof. In the drawing, the extraction position 9 represents the center position in plan view of the tip portion 5a of the tool 5 when the tool 5 is pulled out upward. By rotating the tip portion 5a of the tool 5 located at the extraction position 9, the longitudinal joint portion 8 is formed.

The longitudinal joint 8 refers to a joint formed by rotation of the tool 5 when the tool 5 is located at the extraction position 9. The longitudinal joint portion 8 shown in Fig. 3(a) and Fig. 3(b) is not yet expanded. The basic outer edge 8or of the terminal joint 8 represents the outer edge in an unexpanded state. That is, the basic outer edge 8or corresponds to the outer edge of the joint formed by rotation of the tool 5 when the tool 5 is located at the extraction position 9. The basic outer edge 8or of the longitudinal joint 8 is positioned to surround the tip 5a of the tool 5 located at the extraction position 9.

In Fig. 3(a), the joint portion 7 drawn above the basic outer edge 8or of the longitudinal joint portion 8 is formed when the tool 5 starts to move from the insertion position 4. (See Figure 2(a)). On the other hand, the joint portion 7 drawn below the extraction position 9 is formed just before the tool 5 reaches the extraction position 9 (FIGS. 2(b) and 2(c)). . That is, as shown in Fig. 3(a) and Fig. 3(b), when the tool 5 reaches the extraction position 9, an annular joint portion is formed in a plan view as shown in Fig. 2(c). (7) is formed to surround the sealed space (3).

Next, the expansion process is performed. The expansion process is thus carried out, for example, after the joint portion 7 has been formed to surround the sealed space 3 . In the expansion process of this embodiment, the tool 5 first moves a distance R from the extraction position, and then moves to draw a circle of radius R centered on the extraction position 9 ((a in FIG. 4 ), see Figure 4 (b), Figure 5 (a) and Figure 5 (b)).

A circle of radius R centered on the extraction position 9 is an example of a ring surrounding the extraction position. Examples of the ring include any ring shape, such as a perfect circle, an ellipse, or a polygonal ring. In this embodiment, the distance R (radius R) is less than or equal to the diameter of the basic outer edge 8or of the longitudinal joint portion 8. In this way, in the expansion process of the present embodiment, the terminal joint 8 is expanded by moving the tool 5 so that the joint overlaps the entire circumference of the basic outer edge 8or of the terminal joint 8. . The expanded longitudinal joint portion 8 includes “a portion that makes surface contact with each other in the vertical direction” 11. Between the basic outer edge 8or and the extended outer edge 8ex, an annular area is formed. This area includes “a portion that makes surface contact with each other in the vertical direction” (11). Thereby, sealing properties can be further improved.

As shown in Fig. 5(a), the expanded outer edge 8ex of the longitudinal joint portion 8 is annular in plan view. The basic outer edge 8or of the longitudinal joint 8 is also annular in plan view. The extended outer edge 8ex extends radially from the basic outer edge 8or around the entire circumference. The expanded outer edge 8ex is located at a position spaced radially outward from the annular basic outer edge (or).

The expansion process of this embodiment ends when the tool 5 draws a circle of radius R centered on the extraction position 9 for one round. The number of weeks is not particularly limited and may be multiple weeks. Figure 5(a) and Figure 5(b) show the state at the end of the expansion process.

Next, an extraction process is performed. In the extraction process of this embodiment, the tool 5 is first returned to the extraction position 9. Subsequently, the tool 5 moves upward from the extraction position 9, so that the tool 5 is pulled out from the assembly 10a (metal structure).

According to the manufacturing method of this embodiment, since the joint portion 7 is formed so that the longitudinal joint portion 8 is expanded, the tool 5 is pulled upward from the extraction position 9 to be recessed at the extraction position 9. Even if a portion (not shown) is formed, the joint portion 7 (specifically, the expanded longitudinal joint portion 8) can remain around the concave portion.

The remaining joint portion 7 can prevent or suppress communication between the exterior and interior of the assembly 10a (metal structure) (e.g., the sealed space 3) through the concave portion. Therefore, high sealing properties are obtained. Additionally, this makes it possible to pull out the tool 5 upward. Therefore, it becomes unnecessary to secure a path for moving the tool 5 to the side of the assembly 10a (metal structure). Therefore, the design freedom of the sealed space 3 can be improved.

The present invention is not limited to the above-described embodiments. As an embodiment, the following form can be adopted.

In this embodiment, after the tool is moved from the insertion position to the extraction position to form a sealing space in the sealing process, the end joint is expanded by performing an expansion process, and then the tool is returned to the extraction position and the tool is extracted. Pull it out upward from its position. However, the sequence of these operations is not limited to this embodiment. Although it is necessary that the end joint be expanded before the tool is pulled upward from the extraction position, the sequence of other operations is not particularly limited.

For example, when the insertion position and the extraction position are the same, first, the tool is moved to draw a ring surrounding the insertion position (extraction position), thereby forming an extended end joint in advance. , After that, the tool may be moved to the extraction position to form a sealed space, and the tool may be removed from the extraction position.

In this case, when the tool reaches the extraction position, the expanded longitudinal joint has already been formed. That is, once the tool reaches the extraction position, the expansion process and extraction process may be performed in the order of the expansion process and extraction process, or the expansion process may be performed before the tool reaches the extraction position. That is, regarding the order of the sealing process and the expansion process, either the sealing process or the expansion process may come first. The sealing process, expansion process, and extraction process are performed with the tool inserted, and the tool is not extracted during the process.

When the sealing process, the expansion process, and the extraction process are performed as one set of processes, one or more sealed spaces can be formed by one set of processes. On the other hand, one sealed space can also be formed through a plurality of sets of processes.

The expansion process is performed continuously with the sealing process, and the tool insertion depth in the expansion process is preferably the same or substantially the same as the tool insertion depth in the sealing process. Substantial here means that deviation due to rotation and movement of the tool is allowed. In the sealing process, the movement path of the tool includes “parts in surface contact with each other in the vertical direction” around the entire outer edge of the sealing space, and in the expansion process, the extended longitudinal joint portions include “portions in surface contact with each other in the vertical direction.” It is desirable to include a “part where we interview each other.” The sealability of the sealed space can be improved.

In this embodiment, the extraction position 9 is the same as the insertion position 4. However, the extraction position does not necessarily have to be the same as the insertion position. In this embodiment, the annular path in plan view, which is set to surround the sealing space 3 to form the sealing space 3, includes both the insertion position 4 and the extraction position 9. However, the annular path when viewed in plan need not necessarily include an insertion or extraction site.

The extraction position may be outside the annular path in plan view, that is, a position further away from the enclosed space than the annular path in plan view. In that case, the tool moves along an annular path in plan view, for example to seal the sealing space, and then moves to an extraction position located outside the annular path in plan view, and performs an expansion process at the extraction position. You can do it. Since the extraction position is located outside the annular path in plan view, the longitudinal joint can be expanded even if the distance between the annular path and the sealing space in plan view is relatively short.

The use of the metal structure manufactured by the above-described manufacturing method is not particularly limited. For example, the metal structure may be a hollow metal structure used in a state where the sealed space 3 is hollow. The metal structure can be preferably used as a heat transfer metal structure installed to be in contact with or close to an object to be heat exchanged, heated or cooled. The metal structure can be suitably used so that the sealed space 3 functions as a flow path or reservoir for fluid. The fluid in question is, for example, a gas or liquid.

When the metal structure is used as a metal structure for heat transfer, the fluid is, for example, a heat transfer fluid such as a refrigerant. The metal structure cannot be used as a vehicle member mounted on a vehicle, for example. Metal structures are used for non-mobile purposes, for example. Metal structures are not used in environments subject to vibration, for example, due to engine or vehicle driving.

Metal structures are used, for example, in vacuum. And, vacuum refers to the state of space filled with gas at a pressure lower than atmospheric pressure. The metal structure is installed, for example, in contact with or close to an object to be cooled at 500°C or higher. The metal structure is used, for example, in an atmosphere of 500°C or higher. The metal structure has sealing properties that can prevent leakage of fluid from the sealed space even at temperatures above 500°C. Therefore, the metal structure can be preferably used as a metal structure for heat transfer in a high temperature and vacuum environment as described above. A metal structure can be preferably used, for example, as a backing plate. In this case, examples of the object to be cooled include a sputtering target.

Additionally, the method for manufacturing a metal structure may further include the following steps. For example, the method for manufacturing a metal structure may include a temporary joining process of the main body portion 1 and the cover portion 2 between the assembling process and the sealing process. The temporary welding process is a process of performing friction stir welding in the form of dots and/or broken lines. Before the temporary joining process, the main body portion 1 and the cover portion 2 are not joined. In the sealing process, the main body portion 1 and the cover portion 2 are linearly joined. In this way, deformation can be more effectively prevented or suppressed by performing dot-shaped and/or broken-line bonding between the non-bonded state and the linear bonded state. Additionally, after the sealing process, a flattening treatment may be performed to remove burrs generated by the sealing process. Additionally, in the sealing process, the tool 5 may be inclined. In addition, it is also possible to measure against leakage by leaving a column-shaped protrusion below the extraction position and performing the expansion process and extraction process in the same direction as in the present invention.

In addition, the numerical values, materials, structures, shapes, etc. mentioned in the above-described embodiments and examples are merely examples, and numerical values, materials, structures, shapes, etc. different from these may be used as necessary.

1: main body
1r: recess
1u: top surface
1V: bottom surface
2: cover part
2b: bottom surface
2u: top surface
3: sealed space
3a: Through hole
4: Insertion position
5: Tool
5a: tip
6: border
7: joint
8: End joint
8or: basic outer edge
8ex: Extended outer edge
9: extraction position
10a: assembly
11: Parts that face each other in the vertical direction

Claims (8)

A method of manufacturing a metal structure having at least one sealed space therein, comprising:
The metal structure includes two metal members joined by friction stir welding while overlapping each other in the vertical direction, and the two metal members overlap each other in the vertical direction, thereby forming the two metal members. Configured to form an assembly having an internal space to be the at least one sealing space therebetween,
The manufacturing method is,
A preparation process of preparing the two metal members;
an assembly process of forming the assembly by overlapping the two metal members in the vertical direction;
The two metal members are inserted into the upper surface of the assembly while rotating the tool for friction stir welding, and the tool is moved so that the at least one sealing space is formed between the two metal members. a sealing process of forming a joint to be joined in the vertical direction along a movement path of the tool;
Before withdrawing the tool from its extraction position on the top surface of the assembly, move the tool to form the joint to expand the longitudinal joint formed when the tool reaches the extraction position. When the tool moves, the tool passes through a portion where the two metal members are in surface contact with each other in the vertical direction, thereby causing the longitudinal joint portion to move the two metal members in the vertical direction. Expanding the longitudinal joint to include portions in surface contact with each other, and making it possible to leave the expanded longitudinal joint around the concave portion even if a concave portion is formed at the extraction position when extracting the tool. process; and
Moving the tool to the extraction position located inside the expanded longitudinal joint so that even if a concave is formed at the extraction position by extracting the tool, the expanded longitudinal joint remains around the concave portion, and An extraction process of extracting the tool from the extraction position;
A method of manufacturing a metal structure comprising a. According to paragraph 1,
In the expansion process, the longitudinal joint is expanded by moving the tool so that the joint overlaps the entire outer edge of the longitudinal joint. According to claim 1 or 2,
In the expansion step, the end joint is expanded by moving the tool to draw a ring surrounding the extraction position. According to claim 1 or 2,
In the expansion process, the tool moves so that the expanded end joint has a distance from the sealing space in a plan view. According to claim 1 or 2,
A method of manufacturing a metal structure, wherein the sealed space is configured to prevent fluid from entering and exiting between the inside and the outside. According to claim 1 or 2,
A method of manufacturing a metal structure, wherein the metal structure is a metal structure for heat transfer that is installed in contact with or close to an object to be heat exchanged, heated or cooled. delete delete