Joining method and joining device

Abstract

To provide a joining method and joining device capable of more reliably joining members having different material melting points.SOLUTION: A joining method according to an embodiment joins a plate-shaped first member mainly composed of a first metallic element and a plate-shaped second member mainly composed of a second metallic element that has a higher melting point than the first metallic element and has a eutectic point with the first metallic element. The joining method includes a step of overlapping a second end portion of the second member on a first end portion of the first member. The joining method further includes a joining step in which the second end portion is pressed toward the first member by a frustoconical or conical tip of a rotating tool, and the tip of the rotating tool travels along the end face on the second member side of the first end portion. In the joining step, the rotational direction of the tool on the front side on which the tool travels is the direction heading from the second member toward the first member.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to a joining method and a joining device.

Background Art

[0002] A technique has been proposed in which an end portion of a plate-like member containing a material with a relatively low melting point and an end portion of a plate-like member containing a material with a relatively high melting point are overlapped and joined to obtain a butt joint. The overlapped end portions are pressed with a rotated tool, and the end portions are joined to each other by using frictional heat.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The problem to be solved by the present invention is to provide a joining method and a joining device capable of more reliably joining members having different melting points of materials.

Means for Solving the Problems

[0005] The joining method according to the embodiment is a joining method for joining a plate-shaped first member mainly composed of a first metal element and a plate-shaped second member mainly composed of a second metal element having a melting point higher than that of the first metal element and having a eutectic point with the first metal element. The joining method includes a step of overlapping a second end portion of the second member on a first end portion of the first member. The joining method includes a joining step of pressing the second end portion toward the first member by a frustum-conical or conical tip portion of a rotated tool and causing the tip portion of the rotated tool to travel along an end surface on the second member side of the first end portion. In the joining step, the rotation direction of the tool on the front side where the tool travels is a direction from the second member toward the first member.

Brief Description of the Drawings

[0006]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

[0007] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. The drawings are schematic or conceptual, and the relationships between the thicknesses and widths of the respective parts, the ratios of the sizes between the parts, etc. are not necessarily the same as those in reality. Even when representing the same part, the dimensions and ratios may be represented differently in the drawings. In the present specification and each figure, the same reference numerals are given to elements similar to those already described, and detailed descriptions are appropriately omitted.

[0008] FIGS. 1(a) and 1(b) are schematic cross-sectional views illustrating a bonding method according to an embodiment. FIG. 2 is a schematic perspective view illustrating a bonding method according to an embodiment. FIG. 3 is a schematic plan view illustrating a bonding method according to an embodiment. FIG. 3 corresponds to the state of FIG. 2 as viewed from above.

[0009] First, as shown in FIG. 1(a), the first member 101 and the second member 102 are placed on the backing 200. At this time, the end portion (second end portion 12) of the second member 102 is overlapped on the end portion (first end portion 11) of the first member 101.

[0010] The first member 101 and the second member 102 can be, for example, thin flat plate-like plate materials. There is no particular limitation on the thickness of the first member 101 and the thickness of the second member 102. For example, these thicknesses can be 2 mm or less. Also, the thickness of the second member 102 may be the same as or different from the thickness of the first member 101.

[0011] The first member 101 contains a first metal element as a main component. The second member 102 contains a second metal element as a main component. The melting point of the first single metal composed of the first metal element is lower than the melting point of the second single metal composed of the second metal element. The solidus temperature of the first member 101 is lower than the solidus temperature of the second member 102. The first metal element and the second metal element have a eutectic point, and when the first single metal and the second single metal are in direct contact, they can be melted at a temperature lower than their respective melting points. Note that the main component of a certain member means the element with the highest content (mass percentage) among the elements constituting the member.

[0012] As an example, the first metal element is aluminum and the second metal element is copper. The first member 101 can be made of aluminum, an aluminum alloy, etc., and the second member 102 can be made of copper, a copper alloy, etc. Not limited to this, the first metal element and the second metal element can be a combination described below that causes a eutectic reaction. First metal element Second metal element Magnesium Aluminum Iron Titanium Nickel Titanium Silver Copper

[0013] In the description of the embodiment, the direction perpendicular to the upper surface 101a of the first member 101 before joining is defined as the Z-axis. Directions perpendicular to the Z-axis and orthogonal to each other are defined as the X-axis and the Y-axis. In FIG. 1, the left-right direction of the figure is the X-axis and the depth direction is the Y-axis. The direction from the backing 200 toward the first member 101 is defined as "up", and the opposite direction is defined as "down". The Z-axis is a direction along the up-down direction. The first end 11 is the end of the first member 101 on the X-axis, and the second end 12 is the end of the second member 102 on the X-axis. The mutually overlapping first end 11 and second end 12 extend in the Y-axis. That is, the first end 11 includes a side extending in the Y-axis of the first member 101. The second end 12 includes a side extending in the Y-axis of the second member 102.

[0014] For example, when the thickness of the first member 101 and the thickness of the second member 102 are about 1 mm, the length along the X-axis of the portion of the second member 102 that overlaps the first member 101 (the overlapping margin) can be about 2 mm to 6 mm.

[0015] As shown in Fig. 1(a), a rotating tool 301 (hereinafter, the rotating tool may be referred to as a "rotating tool") is disposed above the second end portion 12 of the second member 102 and the vicinity thereof. Then, as shown in Fig. 1(b), the position of the rotating tool 301 is lowered, and the second end portion 12 of the second member 102 and the vicinity thereof are pressed by the rotating tool 301.

[0016] As shown in Fig. 1(a), the tool 301 has a base portion 301b and a tip portion 301c. The base portion 301b and the tip portion 301c are integrally formed. For example, the tip portion 301c is a convex portion formed by processing one end portion of the columnar base portion 301b. There is no particular limitation on the materials of the base portion 301b and the tip portion 301c, but a material having a higher melting point and harder than the first member 101 and the second member 102 to be joined is used. The materials of the base portion 301b and the tip portion 301c can be, for example, tool steel, tungsten alloy, ceramic, iridium alloy, cubic boron nitride, etc.

[0017] The tip portion 301c is, for example, frustum-shaped. In this case, the tip portion 301c has a tip surface s1 and a side surface s2. The tip surface s1 is located at the lower end of the tool 301 and is, for example, circular and orthogonal to the central axis 301a (the central axis of the tip portion 301c) of the tool 301. The area of the tip surface s1 is smaller than the cross-sectional area in a plane perpendicular to the central axis 301a of the base portion 301b. The side surface s2 surrounds the central axis 301a and connects the tip surface s1 and the side surface of the base portion 301b. The side surface s2 is, for example, inclined with respect to the central axis 301a and approaches the central axis 301a as it moves away from the base portion 301b. Note that the tip surface s1 may be a flat surface, a curved surface, or a spherical surface. The tip portion 301c may be conical.

[0018] Note that the side surface s2 may be formed not only by a single curved surface but also with steps or grooves provided. That is, the range of the frustum of a cone shape (or conical shape) includes not only a precise frustum of a cone (or cone) but also a substantially frustum of a cone shape (or substantially conical shape).

[0019] The central axis 301a is parallel to the Z-axis, for example. The central axis 301a is the rotation axis of the tool 301. Also, when the thicknesses of the first member 101 and the second member 102 are each 1 mm, the diameter (the maximum length in the X direction) of the tip portion 301c can be about 6 mm to 10 mm.

[0020] The first position P1 is a position in the X-Y plane where, in the state before the joining process shown in Fig. 1(a), the end (the side overlapping the second end portion 12 and extending in the Y-axis direction) of the first member 101 on the second member 102 side is located. The height H1 is the position on the Z-axis where the upper surface 101a of the first member 101 is located in the state before the joining process shown in Fig. 1(a). The height H2 is the position on the Z-axis where the upper surface 102c of the second member 102 is located in the state before the joining process shown in Fig. 1(a). The upper surface 102c is a region of the upper surface of the second member 102 that does not overlap with the first member 101 and extends along the X-Y plane. The height H2 is the position of the upper surface of the portion of the second member 102 other than the end portion related to the joining with the first member 101. For example, the height H2 is the position on the Z-axis of a region parallel to the X-Y plane, for example, of the upper surface of the second member 102. Note that the height H2 hardly changes even after the joining process.

[0021] On the X-axis, the central axis 301a of the rotary tool 301 is positioned at the end of the first member 101 on the side of the second member 102, at the first position P1, or on the side of the second member 102 rather than the first position P1. When the central axis 301a is at the first position P1, the lower part of the central axis 301a in the Z-axis direction is the end of the first member. When the central axis 301a is offset from the first position P1 towards the second member 102, there is no first member 101 on the extension line of the central axis 301a in the downward direction of the Z-axis, and only the second member 102 remains. Note that the second position P2 is the position in the X-Y plane where the end of the second member 102 on the side of the first member 101 (the side overlapping with the first end portion 11 and extending in the Y-axis direction) is located in the state before the joining process shown in Fig. 1(a).

[0022] Also, for example, as shown in Fig. 1(a), the distance L on the X-axis between the central axis 301a of the rotary tool and the second position P2 can be longer or shorter than the distance R between the central axis 301a and the outer peripheral end of the tip portion 301c, and joining is still possible. However, if L is too short, the side surface s2 of the rotary tool 301 will contact the first member 101, so the distance L needs to be within an appropriate range.

[0023] When the rotated rotary tool 301 is lowered to the position shown by the solid line in Fig. 1(b), the tip portion 301c of the rotary tool 301 contacts the second end portion 12 of the second member 102. When the rotary tool 301 is further lowered, the contact surface C1 between the first member 101 and the second member 102 is pressurized and plastically deformed. Due to this plastic deformation, the clean surfaces of the first member 101 and the second member 102 are exposed, and contact between the clean surfaces occurs at the contact surface C1. The rotational speed of the rotary tool 301 can be, for example, about 4000 rpm to 10000 rpm.

[0024] When the second member 102 is pressurized downward in the Z-axis direction by the rotary tool 301, frictional heat is generated between the rotary tool 301 and the second member 102. Due to the generated frictional heat, the second end portion 12 of the second member 102 and its vicinity are heated, and the temperature rises. Also, the heat of the second member 102 is transmitted to the first member 101, causing the temperature of the first end portion 11 of the first member 101 and its vicinity to rise.

[0025] When the rotational speed of the rotary tool 301 is appropriately selected, the temperature of the contact surface C1 between the first member 101 and the second member 102 exceeds the eutectic point of the first metal element and the second metal element. When the temperature exceeds the eutectic point, eutectic melting occurs at the contact surface C1, and the surfaces of the first member 101 and the second member 102 at the contact surface C1 melt, generating a melt mainly composed of the first metal element and the second metal element.

[0026] By gradually lowering the rotary tool 301, the melt is extruded from the contact surface. Metal oxides, contaminants, etc. on the surfaces of the first member and the second member are incorporated into the melt and are also extruded from the contact surface. As a result, the surfaces facing the contact surface C1 of the first member 101 and the second member 102 become clean surfaces with almost no oxides, contaminants, etc. Next, melting occurs on the surfaces of the first member 101 and the second member 102 after the melt is extruded, and the generated melt is discharged from the contact portion. By repeating this, the area of the contact surface C1 between the first member 101 and the second member 102 gradually increases.

[0027] At this time, since the contact surface C1 is pressurized by the side surface s2 of the rotary tool 301, a pressure difference occurs in the Z-axis direction. As a result, the contact surface C1 becomes an inclined surface that follows the side surface s2 of the rotary tool 301 to a certain extent.

[0028] Further, lower the rotary tool 301 to the position indicated by the two-dot chain line in Fig. 1(b). That is, further move the rotary tool 301 to the side of the first member 101 (the side of the backing 200), press the overlapping portion of the second member 102 and the first member 101, and hold this state for several seconds. The position of the tip of the rotary tool 301 on the Z-axis can be selected so as to obtain a joined body with the intended shape of the first member 101 and the second member 102. For example, when the thicknesses of the first member 101 and the second member 102 are the same and a joined body in which the first member 101 and the second member 102 are arranged at substantially the same height is to be obtained, the position of the tip of the rotary tool 301 on the Z-axis is aligned with the height H2 of the upper surface of the second member 102. For example, when the thicknesses of the first member 101 and the second member 102 are 1 mm, the joining device is controlled so that the variation in the Z-axis position is within 0.2 mm.

[0029] Then, for example, from the position of the rotary tool 301 indicated by the two-dot chain line in Fig. 1(b), as shown in Figs. 2 and 3, move the rotary tool 301 in the traveling direction Dm. The traveling direction Dm is the direction along the Y-axis. That is, the tip portion 301c of the rotary tool 301 presses the second end portion 12 (and the vicinity of the second end portion 12 of the second member 102) toward the first member 101, and the tip portion 301c of the rotary tool 301 travels along the second end portion 12 (the overlapping portion of the first end portion 11 and the second end portion 12). When the rotary tool 301 moves, the pressure and temperature of the contact surface C1 between the first member 101 and the second member 102 formed in the step of lowering the rotary tool 301 decrease and the eutectic melting stops, and a part of the first member 101 and a part of the second member 102 are joined. At the contact surface between the first member 101 and the second member 102 in front of the traveling direction of the rotary tool 301, exposure and contact of the clean surface due to plastic deformation of the surfaces of the first member 101 and the second member 102, eutectic melting, melt discharge, and expansion of the contact surface occur due to the passage of the rotary tool 301. After the passage of the rotary tool 301, the pressure and temperature of the contact surface decrease and the eutectic melting stops, and a part of the second member 102 and a part of the first member 101 are joined to each other.

[0030] For example, in the joining process, the position of the Z-axis of the tip of the rotary tool 301 (for example, the tip surface s1) can be within a range of 20% or less of the thickness T102 of the second member 102 with respect to the height H2 (first height) shown in FIG. 1(a). That is, for example, the difference between the position of the tip surface s1 on the Z-axis and the position of the upper surface 102c on the Z-axis is 20% or less of the thickness T102 of the second member 102. Thereby, for example, in the joining process, it is possible to suppress the rotary tool 301 from contacting the first member 101. The rotary tool 301 does not have to contact the first member 101. Note that the thickness T102 corresponds to the length of the Z-axis of the portion of the second member 102 that extends along the X-Y plane.

[0031] In the above-described joining process, a part of the melt generated by eutectic melting and extruded from the contact surface between the first member 101 and the second member 102 may enter between the second member 102 and the backing 200. When the above-mentioned melt enters between the second member 102 and the backing 200, the second member 102 is lifted. The lifted portion of the second member 102 is pressurized by the rotary tool 301. Therefore, when the vicinity of the end of the second member 102 is deformed by the pressurization by the rotary tool 301, the thickness of the vicinity of the end of the second member 102 becomes thinner due to the above-mentioned melt that has entered. That is, the thickness of the vicinity of the end of the second member 102 decreases due to the above-mentioned melt that has entered. When the thickness of the vicinity of the end of the second member 102 decreases, the joining strength decreases or the electrical resistance of the joined portion increases.

[0032] Therefore, in the joining method according to the embodiment, a part of the melt is stored inside the recess 200a that opens on the surface of the backing 200. If the recess 200a is provided, it is possible to prevent the melt from entering between the second member 102 and the backing 200, so that it is possible to suppress a decrease in the thickness of the vicinity of the end of the second member 102.

[0033] On the portion for placing the first member 101 of the backing 200, there is a holding mechanism that determines the positional relationship between the concave portion 200a of the backing 200 and the first member 101 and fixes it to the backing. When the end of the first member 101 on the side opposite to the second member 102 is abutted against this holding mechanism, the position of the end of the first member 101 on the second member 102 side in the X-axis may be the same as the opening edge on the first member 101 side of the concave portion 200a in the X-axis. Further, it may be a position separated by about 0.5 mm in the X-axis from the opening edge on the first member 101 side of the concave portion 200a toward the first member 101 side, or it may be separated by about 0.2 mm in the X-axis from the end on the first member 101 side of the concave portion 200a toward the second member 102 side so that the first end portion 11 of the first member 101 slightly protrudes above the concave portion 200a. That is, the distance between the end of the first member 101 on the second member 102 side and the opening edge of the concave portion 200a does not need to be extremely long. With such a positional relationship between the first member 101 and the concave portion 200a, it is possible to effectively suppress the material of the first member 101 from entering between the second member 102 and the backing 200. FIG. 1 shows a case where the end of the concave portion 200a on the first member 101 side is at the same position as the end of the first member 101.

[0034] Also, for example, as shown in FIG. 3, the rotation direction Dr of the tool 301 is a direction from the second member 102 toward the first member 101 on the front side surface (traveling front surface 301f) where the tool 301 travels. Thereby, the first member 101 and the second member 102 can be joined more reliably.

[0035] As described above, the first member 101 and the second member 102 can be joined to manufacture a joined body having a butted joint between the first member 101 and the second member 102. In the manufactured joined body, a eutectic alloy in which the melt stored inside the concave portion 200a has solidified is adhered, but the adhered material may be removed by machining or the like.

[0036] FIGS. 4(a) and 4(b) are microscope photographs illustrating a joined body formed by the joining method according to the embodiment. FIG. 4(b) is an enlarged photograph of part A in FIG. 4(a). In order to join the second end portion 12 of the second member 102 superposed on the first end portion 11 of the first member 101 by pressing with a rotary tool having a truncated cone shape or a conical shape at the tip, as shown in FIG. 4(a), the joint surface 111a between the first member 101 and the second member 102 is inclined with respect to the thickness direction of the first member 101.

[0037] Generally, when manufacturing a joined body having a butted joint between plate-like members, end faces perpendicular to the surfaces of the members, that is, the ends are joined. When the thickness of the member is small, the joint area becomes small, and it may be difficult to obtain the required joint strength. On the other hand, according to the joining method according to the embodiment, since the inclined joint surface is formed and joined in the vicinity of the end portion of the member, the joint area can be increased as compared with the general joining method. Therefore, even when the thickness of the member is small, it becomes easy to obtain the required joint strength.

[0038] When joining members made of different metal elements, a layer containing an intermetallic compound (IMC) may be formed on the joint surface. For example, when the first member 101 is aluminum or an aluminum alloy and the second member 102 is copper or a copper alloy, a formed layer 103 mainly composed of an intermetallic compound is formed. The formed layer 103 formed on the joint surface 111a shown in FIG. 4 is composed of CuAl, CuAl2, etc., which are intermetallic compounds of aluminum and copper.

[0039] Intermetallic compounds are often brittle materials. In that case, when the thickness of the production layer 103 increases, the bonding strength decreases. The intermetallic compound of copper and aluminum is a brittle material, and the literature (Xie, Yamaguchi, Nishi: Formation of Intermetallic Compounds at the Bonding Interface of Aluminum / Copper Clad Materials, Journal of the Japan Institute of Metals, 75-3 (2011), 166-172.) shows that when the thickness of this intermetallic compound layer increases, the bonding strength decreases. For example, when the thickness of the intermetallic compound layer is 4 μm, the strength is 90 MPa, and when the thickness increases to 8 μm, the strength decreases to 60 MPa. Intermetallic compounds tend to become thicker as the heating time increases.

[0040] In the bonding method according to the embodiment, without applying excessive frictional heat to the bonding portion, by selecting the rotational speed and traveling speed of the rotating tool so that the temperature of the bonding surface drops in a short time behind the traveling rotating tool, the thickness of the production layer 103 can be made around 1 μm. When the production layer is an intermetallic compound layer and the thickness of the layer is 1 μm, the strength is about 90 MPa. For example, when the angle formed by the bonding surface and the upper surface of the first member 101 is 30 degrees, the bonding area is twice that when the bonding surface is a vertical plane with respect to the upper surface 101a of the first member 101. That is, the strength against the tension in the left-right direction in the cross-sectional photograph of the bonding portion shown in FIG. 4 is equivalent to 180 MPa. For example, the tensile strength of aluminum A1050-H24 used in bus bars etc. is 95 MPa. That is, it can be said that the tensile strength of the bonding surface of 180 MPa exceeds the member strength and is a necessary and sufficient strength.

[0041] As described above, in the joining method according to the embodiment, plates of dissimilar metals having a eutectic point can be joined with high joining strength. In this joining, while pressing the overlapping portion of the first member 101 and the second member 102 with a rotary tool, the rotary tool is caused to travel along the overlapping portion. In this case, joining is possible even if the relationship between the traveling direction of the rotary tool and the rotational direction of the rotary tool 301 is changed, but the quality of the joining changes. For example, at the traveling front surface 301f of the rotary tool 301, when the rotational direction of the rotary tool 301 is from the first member 101 toward the second member 102, non-joining is likely to occur at the upper part of the inclined joining surface. On the other hand, at the traveling front surface 301f of the rotary tool 301, when the rotational direction of the rotary tool 301 is from the second member 102 toward the first member 101, it has been found that the occurrence of non-joining is suppressed and a well-finished joining can be obtained over the entire surface of the joining surface.

[0042] The reason for this is considered as described below. Figs. 5(a) to 5(c) are schematic diagrams illustrating the pressure distribution in the joining process. The tool 301 moves on the Y-axis from the back to the front side of the figure. The arrows in Figs. 5(a) to 5(c) schematically represent the pressure distribution. Fig. 5(a) shows the distribution of the pressure component in the Z-axis direction. Fig. 5(b) shows the distribution of the pressure component in the X-axis direction when the rotational direction of the rotary tool 301 at the traveling front surface 301f is from the second member 102 side toward the first member 101 side. Fig. 5(c) shows the distribution of the pressure component in the X-axis direction when the rotational direction of the rotary tool 301 at the traveling front surface 301f is from the first member 101 side toward the second member 102 side. Note that at the traveling rear surface of the tool 301, since the tool 301 and the second member 102 are not in contact, the pressure component in the X-axis direction due to the rotation of the tool 301 is smaller than that at the traveling front surface of the tool 301. In this joining, a rotary tool with a frustum - of - cone shape or a conical shape at its tip is moved downward along the Z - axis and brought into contact with the upper surface of the second member 102 and pressed toward the first member 101. Therefore, as shown in Fig. 5(a), the pressure applied to the joining surface becomes lower as it goes toward the upper part of the joining surface, and non - joining is likely to occur. Thus, as shown in Fig. 5(b), if the rotation direction of the rotary tool 301 on the running front surface 301f is set to be from the second member 102 side toward the first member 101 side, in the direction intersecting the central axis 301a (for example, the X - axis), due to the rotation of the rotary tool 301, a horizontal force is applied to the joining surface to increase the pressure, and joining can be achieved. For example, affected by the plastic flow of copper occurring around the rotary tool 301, the pressure of the X - axis at the upper part of the joining surface increases, compensating for the low pressure of the Z - axis at the upper part of the joining, and a good joining can be obtained. On the contrary, as shown in Fig. 5(c), if the rotation direction of the rotary tool 301 is set to be from the first member 101 side toward the second member 102 side on the running front surface 301f, a force in the direction of reducing the pressure on the joining surface is applied, and non - joining at the upper part of the joining surface is likely to occur. For example, the pressure of the X - axis at the upper part of the joining surface becomes low, and joining failure is likely to occur.

[0043] Figs. 6(a) to 6(d) are schematic plan views illustrating the joining method according to the embodiment. In the embodiment, the above - described joining process may be divided and performed multiple times. In this example, the joining process includes a first process shown in Figs. 6(a) and 6(b) and a second process shown in Figs. 6(c) and 6(d).

[0044] As shown in Fig. 6(a), the rotary tool 301 is disposed at the first starting point SP1 in the X-Y plane. That is, the rotary tool 301 is disposed at a position where the central axis of the rotary tool 301 overlaps with the first starting point SP1 in the X-Y plane. Then, by rotating the rotary tool 301 located at the first starting point SP1 in the direction Dr1 and moving it downward along the Z-axis (toward the overlapping portion side of the first member 101 and the second member 102), the tip 301c of the rotary tool 301 (see Fig. 1(a)) is brought into contact with and pressed against the second end portion 12 of the second member 102 and its vicinity. That is, at the first starting point SP1, the second member 102 is pressed toward the first member 101 by the rotary tool 301. The first starting point SP1 is, for example, the center in the Y direction of the second end portion 12.

[0045] After keeping the rotary tool 301 lowered to a predetermined position on the Z-axis for several seconds, the rotary tool 301 is run from the first starting point SP1 in the traveling direction Dm1. The traveling direction Dm1 is a direction along the second end portion 12, that is, a direction along the Y-axis. The traveling direction Dm1 is a direction from the first starting point SP1 toward one end 102a of the second member 102 on the Y-axis.

[0046] As shown in Fig. 6(b), the rotary tool 301 is run to the first end point EP1. That is, the rotary tool 301 is run until the central axis of the rotary tool 301 overlaps with the first end point EP1 in the X-Y plane. The first end point EP1 may be, for example, a point on one end 102a of the second member 102.

[0047] In this way, in the first step, the rotary tool 301 travels while heating and pressing the range from the first starting point SP1 to the first end point EP1 on the Y-axis in the overlapping portion of the first member 101 and the second member 102 by frictional heat. When the central axis of the rotary tool 301 reaches the first end point EP1, it is held in that state for, for example, 1 second, the rotary tool 301 is moved upward along the Z-axis (to the opposite side of the overlapping portion of the first member 101 and the second member 102), and the rotation is stopped.

[0048] Next, as shown in FIG. 6(c), the rotary tool 301 is disposed at the second starting point SP2 in the X-Y plane. That is, the rotary tool 301 is disposed at a position where the central axis of the rotary tool 301 overlaps with the second starting point SP2 in the X-Y plane. Thereafter, while rotating the rotary tool 301 located at the second starting point SP2 in the direction Dr2 opposite to the first step, it is moved downward (toward the side of the first member 101) to a predetermined position on the Z axis. The position of the rotary tool 301 on the Z axis in the second step may be the same as that in the first step, or may be lowered from the position on the Z axis in the first step.

[0049] Here, the position of the second starting point SP2 on the Y axis is between the position of the first starting point SP1 on the Y axis and one end 102a of the second member 102 in the Y direction. That is, in a plan view, the traveling start point of the rotary tool 301 after the second step is within the traveling range of the rotary tool 301 in the immediately preceding step. The position of the second starting point SP2 on the X axis may be the same as the position of the first starting point SP1 on the X axis.

[0050] Then, the rotary tool 301 is caused to travel from the second starting point SP2 in the traveling direction Dm2. The traveling direction Dm2 is a direction along the second end portion 12, that is, a direction along the Y axis. The traveling direction Dm2 is a direction from the second starting point SP2 toward the other end 102b of the second member 102 on the Y axis.

[0051] As shown in FIG. 6(d), the rotary tool 301 is caused to travel to the second end point EP2. That is, the rotary tool 301 is caused to travel until the central axis of the rotary tool 301 overlaps with the second end point EP2 in the X-Y plane. The second end point EP2 may be, for example, a point on the other end 102b of the second member 102. After waiting for several seconds at the second end point EP2, the rotary tool 301 is rotated and moved upward on the Z axis, and the rotation is stopped to complete the joining.

[0052] Thus, in the second step, the rotary tool 301 travels while pressing and heating the unjoined range (the range up to the second end point EP2, on the side of the second end point EP2 rather than the first start point SP1 on the Y-axis) of the overlapping portion of the first member 101 and the second member 102 with frictional heat.

[0053] The height (position on the Z-axis) of the rotary tool 301 traveling in the second step may be, for example, the same as the height of the rotary tool 301 traveling in the first step, or may be a position shifted 0.1 to 0.2 mm downward on the Z-axis.

[0054] FIG. 7 is a schematic plan view illustrating a joining method according to a reference example. In the reference example, the joining process is not divided into a plurality of times. In this case, as shown in FIG. 7, the joining start point is set at a position inside rather than at the end (the other end 102b) in the Y direction of the overlapping portion. The reason for this is that the temperature of the member at the start of joining is often room temperature, and it is necessary to secure the contact area between the rotary tool 301 and the second member 102 and raise the temperature of the contact surface of the first member and the second member to the eutectic point of the first metal and the second metal in a short time. Thus, in order to set the joining start point inside the end, the range from the joining start point to the other end 102b may not be sufficiently heated and pressed, and there is a risk of an unjoined portion occurring.

[0055] On the other hand, in the joining method according to the embodiment, as described above, in the first step, the second end portion 12 is pressed toward the first member 101 by the tip portion 301c of the rotary tool 301, and the rotary tool 301 is caused to travel to a position where the position of the central axis 301a overlaps with one end 102a of the second member 102. In the second step, the second end portion 12 is pressed toward the first member 101 by the tip portion 301c of the rotary tool 301, and the rotary tool 301 is caused to travel to a position where the position of the central axis 301a overlaps with the other end 102b of the second member 102. Thereby, the occurrence of an unjoined portion can be suppressed. Therefore, it becomes possible to more reliably join the first member 101 and the second member 102.

[0056] Also, as described above, in the first step, the rotary tool 301 starts traveling from the first starting point SP1 toward one end 102a. In the second step, the rotary tool 301 starts traveling from the second starting point SP2 toward the other end 102b. The position of the second starting point SP2 in the Y-axis (the first direction from the other end 102b toward the one end 102a) is between the position of the first starting point SP1 in the Y-axis and the position of the one end 102a in the Y-axis. In this way, by setting the traveling starting point of the rotary tool 301 in the second and subsequent joints within the traveling range of the rotary tool 301 in the immediately preceding joint, the generation of unjoined portions can be more suppressed. The first member 101 and the second member 102 can be joined more reliably.

[0057] As shown in FIG. 6(a), in the first step, the rotation direction of the rotary tool 301 on the traveling front surface 301f of the rotary tool 301 is the direction from the second member 102 toward the first member 101. As shown in FIG. 6(c), in the second step, the rotation direction of the rotary tool 301 on the traveling front surface 301f of the rotary tool 301 is the direction from the second member 102 toward the first member 101. Thereby, the first member 101 and the second member 102 can be joined more reliably. In this way, for example, in the second and subsequent joints, the traveling direction and the rotation direction of the rotary tool 301 may be different from those in the immediately preceding joint.

[0058] In the second step, the rotary tool 301 may be brought into contact with the inside of the traveling range (such as the first starting point, etc.) of the rotary tool 301 in the first step, but it does not have to be brought into contact. In the second step, the rotary tool 301 does not have to substantially pressurize the inside of the traveling range of the rotary tool 301 in the first step.

[0059] For example, the second step is started before the temperatures of the first member 101 and the second member 102 heated in the first step drop excessively. Thereby, joining in the second step becomes easy. It is desirable that the second step be started without delay after the end of the first step. Since the temperature of the backing also rises in the first step, the temperatures of the first member and the second member do not drop rapidly. For example, the second step is started within 3 seconds after the end of the first step.

[0060] In the present specification, descriptions regarding the direction in which the rotary tool 301 travels and positions such as height are related to the relative direction and height positions between the rotary tool 301 and the first member 101 and the second member 102. That is, for example, by fixing the positions of the first member 101 and the second member 102 in the X-Y plane and changing the position of the rotary tool 301, the rotary tool 301 may be relatively run with respect to the first member 101 and the second member 102. Conversely, by fixing the position of the rotary tool 301 in the X-Y plane and changing the positions of the first member 101 and the second member 102, the rotary tool 301 may be relatively run with respect to the first member 101 and the second member 102.

[0061] The rotation direction of the rotary tool 301 may be changed between the first step and the second step. Alternatively, the rotation directions of the rotary tool 301 in the first step and the second step may be the same, and the orientations of the first member 101 and the second member 102 may be changed.

[0062] Figs. 8(a) to 8(e) are photographs illustrating a joined body formed by the joining method according to the embodiment. Fig. 8(a) is a photograph of the first member 101 and the second member 102 joined by the joining method described with respect to Figs. 6(a) to 6(d), as viewed from above. Figs. 8(b) to 8(e) are optical microscope photographs illustrating the X-axis cross sections of the first member 101 and the second member 102.

[0063] Fig. 8(b) represents a cross section taken along line A1-A2 shown in Fig. 8(a). The line A1-A2 is located in the vicinity of one end 102a of the second member 102. Figure 8(c) represents the cross-section along line A3 - A4 shown in Figure 8(a). The line A3 - A4 is located on the Y-axis between the second starting point SP2 and the line A1 - A2. Figure 8(d) represents the cross-section along line A5 - A6 shown in Figure 8(a). The line A5 - A6 is located on the Y-axis between the first starting point SP1 and the second starting point SP2. Figure 8(e) represents the cross-section along line A7 - A8 shown in Figure 8(a). The line A7 - A8 is located near the other end 102b of the second member 102.

[0064] As shown in Figures 8(b) to 8(e), there is almost no difference in the inclination angle of the joint surface at the position of the joint, and the thickness of the formed layer 103 formed on the inclined joint surface is about 1μm before and after. By the joint method according to the embodiment, the first member 101 and the second member 102 can be joined well.

[0065] Figures 9(a) and 9(b) are schematic cross-sectional views illustrating the joint method according to the embodiment. Figure 10 is a schematic plan view illustrating the joint method according to the embodiment. Figure 10 corresponds to the state of Figure 9(b) as viewed from above. Regarding the Y-axis, the lower part of the figure is referred to as the plus direction, and the upper part of the figure is referred to as the minus direction. In the example shown in Figures 9(a) to 10, the angle and position of the central axis 301a of the tool 301 with respect to the first member 101 and the second member 102 are different from the above-described joint method. That is, in this example, the central axis 301a is inclined with respect to the Z-axis.

[0066] As shown in Figure 9(a), also in this example, the second end 12 of the second member 102 is overlapped on the first end 11 of the first member 101. The central axis 301a of the rotary tool 301 is inclined with respect to the Z-axis. Then, the tool 301 with the inclined central axis 301a is rotated, and the joint process shown in Figure 9(b) is executed. The joint process lowers the position of the rotary tool 301 to, for example, the position indicated by the two-dot chain line in Figure 9(b). The joint process presses the second end 12 of the second member 102 downward along the Z-axis by the tip 301c of the rotary tool 301.

[0067] As shown in FIGS. 9(a) and 9(b), the upper surface 101a of the first member 101 extends in the X-axis (first extending direction). The first member 101 has an end portion (third end portion 13) on the side opposite to the first end portion 11. The third end portion 13 is located on the side opposite to the side of the second member 102 in the joining process. The third end portion 13 is separated from the first end portion 11 in the X-axis. The second member 102 has an end portion (fourth end portion 14) on the side opposite to the second end portion 12. The fourth end portion 14 is located on the side opposite to the side of the first member 101 in the joining process.

[0068] In this example, the tip portion 301c of the tool 301 has a conical shape. The conical shape of the tip portion 301c has a side surface s2 and a vertex. The tip e1 of the tool 301 is the vertex of the conical shape. The tip e1 and the rear end e2 of the tool 301 are on the central axis 301a.

[0069] As shown in FIG. 9(b), in the joining process, the central axis 301a of the tool 301 is inclined with respect to the direction perpendicular to the upper surface 101a (for example, the Z-axis) so as to approach the third end portion 13 in the X-Z plane as it goes from the rear end side of the tool 301 to the tip side of the rotary tool 301. In the joining process, the position Pe1 of the tip e1 of the tool 301 in the X-axis is substantially the same as the position of the end surface on the second member 102 side of the first member 101.

[0070] In the second member 102, the portion strongly pressed by the tool 301 softens due to frictional heat. Then, it is likely to become locally thinner due to the pressing and rotation by the tool 301. In particular, when the second member 102 is a thick plate material, if joined by the method shown in FIGS. 1(a) to 1(b), since the bending rigidity of the second member 102 is high, the portion of the second member 102 pressed by the tool 301 becomes thinner. On the other hand, the portion not strongly pressed is difficult to deform, and the second member 102 may be deformed into a zigzag shape. That is, it is difficult to obtain a joined body with a uniform thickness. This occurs remarkably, for example, when the thicknesses of the first member 101 and the second member 102 are 5 mm or more. As a result, the quality such as the strength and appearance of the joined product deteriorates.

[0071] One method to prevent the above-described problem is to incline the central axis 301a of the tool 301 in the joining process as described above. By this, on the conical side surface s2, the overlapping portion of the first member 101 and the second member 102 and the range from the overlapping portion of the second member 102 to the bending line (bending line L1) of the second member 102 are also pressed, and local deformation of the second member 102 can be suppressed. As a result, the members can be joined more reliably, and a high-quality joined body can be surely obtained.

[0072] In this example, the tip portion 301c of the tool 301 preferably has, for example, a conical shape. The conical shape may be, for example, a substantially conical shape with the tip of the cone rounded.

[0073] For example, in the joining process, let the angle formed by the Z-axis and the central axis 301a be θt. Also, for example, let the apex angle of the conical shape of the tip 301c of the tool 301 be θc. In this case, it is desirable that the relationship -5 < θt - (180 - θc)÷2 < 5 holds. As a result, the angle θd formed by the X-axis and the generatrix closest to the second member 102 on the side surface of the tip 301c having a conical shape becomes 5 degrees or less, and it becomes easier to press the overlapping portion of the first member 101 and the second member 102 with the conical side surface s2. For example, θc satisfies 90° < θc < 180°, and it is preferably 135° or more and 165° or less. Also, if θt and θc are set such that θd becomes 0 degrees, a joined body with a substantially flat upper surface can be obtained.

[0074] Note that the apex angle (θc) of the conical shape is the apex angle of the cross-sectional shape of an isosceles triangle of the tip 301c in the cross-section of the tip 301c in the X-Z plane including the central axis 301a, as shown in FIGS. 9(a) and 9(b). The apex angle of the conical shape is the angle between two straight lines (i.e., for example, generatrices) extending linearly from the end on the base 301b side of the side surface s2 in the shape of the tip 301c in the cross-section.

[0075] For example, as shown in FIG. 9(a), the second member 102 has a central portion 102d and a bent portion 102e. The bent portion 102e is between the central portion 102d and the second end portion 12. The central portion 102d extends in the X direction. Before the joining process (FIG. 9(a)), the bent portion 102e is bent upward from the central portion 102d with respect to the Z-axis and extends to the second end portion 12. For example, before the joining process, the second member 102 is subjected to a bending process of bending the second member 102 along the bending line L1 to form the bent portion 102e. The bending line L1 is substantially parallel to the Y-axis.

[0076] As described above, a concave portion 200a is provided on the surface of the backing 200 on the side of the second member 102. In the joining process shown in FIG. 9(b), the concave portion 200a overlaps the second member 102 on the Z-axis and is located below a part of the second member 102. The concave portion 200a does not have to overlap the first member 101 on the Z-axis.

[0077] As shown in FIG. 9(b), the position PL1 of the bending line L1 on the X-axis is between the position P200a of the opening end on the second member 102 side of the concave portion 200a on the X-axis and the position Ps3 of the outer peripheral end s3 of the rotary tool on the X-axis. Thus, the bending line L1 is within the pressing range of the tip portion 301c of the tool 301. Thereby, the end portion including the bent portion of the second member 102 is pressed by the rotary tool. By increasing the contact area between the rotary tool and the second member 102, the rotational speed of the tool 301 for obtaining the frictional heat necessary for joining can be lowered. Therefore, the amount by which the second member 102 is shaved by the rotation of the tool 301 is reduced, and the upper surface of the second end portion 12 of the second member 102 is shaped to follow the side surface of the tool 301. As a result, a joined body with a substantially flat upper surface can be obtained.

[0078] As shown in FIG. 9(b), the position PL1 of the bending line L1 on the X-axis is between the position Ps3 of the outer peripheral end s3 on the second member 102 side of the tool 301 and the position P200a of the opening end on the second member 102 side of the concave portion 200a of the backrest 200. The position Pe1 of the tip e1 of the tool 301 in the X direction is substantially the same as the position of the end face on the second member 102 side of the first member 101. The overlapping portion of the first member 101 and the second member 102 can be pressed by the side surface s2 along the X-axis of the tool 301.

[0079] As shown in FIG. 10, in the joining step, while pressing the overlapping portion of the first member 101 and the second member 102 with the rotary tool 301 whose central axis 301a is inclined, the rotary tool 301 whose central axis 301a is inclined is made to travel along the overlapping portion. The traveling direction Dm is the Y-axis. When viewed from above as in FIG. 10, the central axis 301a is perpendicular to the Y-axis, for example.

[0080] As shown in FIG. 10, the rotational direction Dr of the tool 301 is the direction from the second member 102 toward the first member 101 on the traveling front surface 301f of the tool 301. Thereby, the first member 101 and the second member 102 can be joined more reliably.

[0081] In FIGS. 1(a) to 3, FIG. 6, etc., as an example, the case where the central axis 301a is parallel to the Z-axis is illustrated. However, in the joining method described above with respect to FIGS. 1(a) to 3, FIG. 6, etc., similar to FIGS. 9(a) to 10, the central axis 301a may be inclined with respect to the Z-axis. For example, in the joining process of inclining the central axis 301a of the tool 301 as shown in FIGS. 9(a) to 10, a first step of running the tool 301 in the positive direction of the Y-axis (FIG. 10) toward one end of the second member 102 and a second step of running the tool 301 in the negative direction of the Y-axis toward the other end of the second member 102 may be included.

[0082] FIG. 11 is a schematic diagram illustrating a joining apparatus according to an embodiment. The joining apparatus 300 shown in FIG. 11 performs the joining method according to the embodiment. The joining apparatus 300 is provided with, for example, a rotary tool 301, a stage 302, a machining unit 303, a moving unit 304, a frame 305, and a controller 306.

[0083] The stage 302 has a backing 200 and a holding unit 201 that positions the first member 101 and the second member 102 and fixes them to the backing 200. On the backing 200, in a state where the vicinity of the end of the second member 102 is superposed on the vicinity of the end of the first member 101, the first member 101 and the second member 102 are placed. The backing 200 can be made of, for example, hot work tool steel. However, the material of the backing 200 is not limited to the exemplified one. Further, the backing 200 has a groove-shaped recess 200a capable of storing a part of the molten liquid extruded from the joining surface. The recess 200a opens on the surface of the backing 200.

[0084] The holding part 201 is provided, for example, on the surface of the backing 200. The holding part 201 holds the first member 101 and the second member 102 placed on the surface of the backing 200. The holding part 201 can be, for example, a chuck or the like. By this holding part 201, the positional relationship between the end of the first member 101 on the side of the second member 102 and the opening edge of the recess 200a is adjusted. For example, the holding part 201 positions the first member 101 on the backing 200 such that the distance between the end face of the first member 101 and the edge of the recess 200a is within 1 mm. For example, as shown in FIG. 1, the end of the first member 101 (the first position P1) is aligned with the position of the recess 200a in the X direction. Also, for example, the first member 101 may be positioned such that the first position P1 and the recess 200a are separated by 0.5 mm in the X direction, or the first member 101 may be positioned such that the end of the first member 101 protrudes 0.2 mm into the opening of the recess 200a.

[0085] The processing part 303 holds the tool 301. The processing part 303 rotates the tool 301. Also, the processing part 303 changes the position of the rotated tool 301 (rotating tool 301). For example, the processing part 303 changes the position of the rotating tool 301 in the Z direction to bring the tip 301c of the rotating tool 301 into contact with the second member 102. The processing part 303 includes, for example, a motor that rotates the rotating tool 301 and a motor that moves the rotating tool 301 in the Z direction. That is, the processing part 303 abuts and presses the rotated rotating tool 301 against the portion of the second member 102 that is overlapped with the first member 101.

[0086] A stage 302 is attached to the moving part 304. The moving part 304 changes the position of the stage 302 in the X direction. Also, the moving part 304 may change the position of the stage 302 in the X and Y directions. The moving part 304 is, for example, a uniaxial table or a biaxial table (XY table). The stage 302 and the moving part 304 may be an electric stage including a motor.

[0087] In this example, the moving part 304 moves the stage 302 to cause the tool 301 to travel relative to the first member 101 and the second member 102. However, it is not limited to this. The moving part may be a mechanism that moves the tool 301 to cause the tool 301 to travel relative to the first member 101 and the second member 102. The moving part 304 causing the tool 301 to travel means moving at least one of the stage 302 and the tool 301 to cause the tool 301 to travel relative to the first member 101 and the second member 102.

[0088] The processing part 303 and the moving part 304 are attached to the frame 305. For example, the processing part 303 is attached above the moving part 304.

[0089] The joining device 300 may further be provided with an angle changing part 307. The angle changing part 307 is installed between the stage 302 and the moving part 304 and changes the inclination of the first member 101 and the second member 102 with respect to the tool 301. That is, by the angle changing part 307, as shown in FIGS. 9(a) to 10, the central axis 301a of the tool 301 can be inclined from the vertical direction with respect to the first member 101, the second member 102, the backrest 200, etc. In this example, the angle changing part 307 is installed between the stage 302 and the moving part 304, but it may also be attached to the frame 305. For the angle changing part 307, a jack that moves up and down by hydraulic pressure, a motor, manual force, etc., an angle changing mechanism using a ball screw, an inclination mechanism that rotates around the Y-axis center, etc. may be used.

[0090] Note that in this example, the angle changing unit 307 changes the inclination of the central axis of the tool 301 with respect to the first member 101 and the second member 102 by moving the stage 302. However, it is not limited to this. The angle changing unit 307 may be a mechanism for changing the inclination of the tool 301. That is, the angle changing unit 307 has at least either a function of inclining the central axis 301a of the tool 301 or a function of inclining the stage 302, thereby changing the relative inclination of the central axis 301a with respect to the first member 101 and the second member 102. For example, the angle changing unit 307 when inclining the tool 301 may be an angle changing mechanism composed of a motor and a ball screw or an angle changing mechanism using a rotating plate.

[0091] The controller 306 includes, for example, an arithmetic unit such as a CPU (Central Processing Unit) and a storage unit such as a memory. The controller 306 is, for example, a computer. The controller 306 controls the operations of the respective elements provided in the joining device 300 based on the control program stored in the storage unit. For example, the controller 306 controls the operations of the respective elements provided in the joining device 300, executes the above-described joining method, and joins the first member 101 and the second member 102 to manufacture a joined body having a butt joint.

[0092] For example, the controller 306 controls the processing unit 303 to execute a pressing operation (joining process) on the processing unit 303. The pressing operation presses the second end portion 12 of the second member 102 stacked on the first end portion 11 of the first member 101 toward the first member 101 by the tip portion 301c of the rotated tool 301. For example, the controller 306 may control the moving unit 304 to execute a traveling operation (joining process) on the moving unit 304. The traveling operation causes the tool 301 to travel with respect to the first member 101 and the second member 102. For example, the controller 306 may control the angle changing unit 307 to execute an angle changing operation on the angle changing unit 307. When the angle changing unit 307 is provided on the processing unit 303 side, the angle changing operation inclines the central axis of the tool 301 in a direction perpendicular to the upper surface 101a of the first member 101 so as to approach the third end portion 13 (see FIG. 9) on the X-axis as it goes from the rear end side to the front end side of the tool 301. When the angle changing unit 307 is provided on the stage 302 and the moving unit 304 side, the stage 302 is inclined so that the first member 101 and the second member 102 are inclined in a direction in which the fourth end portion 14 (FIG. 9) of the second member 102 approaches the tool 301.

[0093] The embodiment may include the following configuration (for example, technical solution). (Configuration 1) A bonding method for bonding a plate-shaped first member mainly composed of a first metal element and a plate-shaped second member mainly composed of a second metal element having a melting point higher than that of the first metal element and having a eutectic point with the first metal element, a step of overlapping the second end portion of the second member on the first end portion of the first member; a bonding step of pressing the second end portion toward the first member by a frustum-shaped or conical tip portion of a rotating tool and causing the tip portion of the rotating tool to travel along an end surface on the second member side of the first end portion; comprising In the bonding step, the rotation direction of the tool on the front side where the tool travels is a direction from the second member toward the first member. The bonding method. (Configuration 2) A bonding method for bonding a plate-shaped first member mainly composed of a first metal element and a plate-shaped second member mainly composed of a second metal element having a melting point higher than that of the first metal element and having a eutectic point with the first metal element, a step of overlapping the second end portion of the second member on the first end portion of the first member; A first step of pressing the second end portion toward the first member by the tip of the rotated tool and causing the tip of the rotated tool to travel toward one end of the second member; A second step of pressing the second end portion toward the first member by the tip of the rotated tool and causing the tip of the rotated tool to travel toward the other end of the second member opposite to the one end; A joining method comprising the above. (Configuration 3) In the first step, the rotation direction of the tool on the front side where the tool travels is the direction from the second member toward the first member, In the second step, the rotation direction of the tool on the front side where the tool travels is the direction from the second member toward the first member, the joining method according to Configuration 2. (Configuration 4) In the first step, the rotated tool starts traveling from the first starting point toward the one end, In the second step, the rotated tool starts traveling from the second starting point toward the other end, The position of the second starting point in the first direction from the other end toward the one end is between the position of the first starting point in the first direction and the position of the one end in the first direction, the joining method according to Configuration 2 or 3. (Configuration 5) The upper surface of the portion of the second member other than the end portion related to the joining with the first member is located at a first height before the joining step, In the joining step, the position of the tip of the tool in the thickness direction is within a range of 20% of the thickness of the second member with respect to the first height, the joining method according to any one of Configurations 1 to 4. (Configuration 6) The end of the first member on the second member side is located at a first position in a plane along the upper surface of the first member before the joining step, In the joining step, the central axis of the tool is at the first position or a position shifted toward the second member side from the first position, and the lower part of the central axis of the tool is the end of the first member or there is no first member. The joining method according to any one of Configurations 1 to 5. (Configuration 7) The upper surface of the first member extends in a first extending direction. The first member has a third end portion located on the opposite side of the second member in the first extending direction. The central axis of the tool in the joining step is inclined with respect to the direction perpendicular to the upper surface so as to approach the third end portion in the first extending direction as it goes from the rear end side to the front end side of the tool. The joining method according to any one of Configurations 1 to 4. (Configuration 8) A joining method for joining a plate-like first member mainly composed of a first metal element and a plate-like second member mainly composed of a second metal element having a melting point higher than that of the first metal element and having a eutectic point with the first metal element, A step of overlapping the second end portion of the second member on the first end portion of the first member, A joining step of pressing the second end portion toward the first member by the conical tip portion of the rotated tool, Comprising The upper surface of the first member extends in a first extending direction. The first member has a third end portion located on the opposite side of the second member in the first extending direction. The central axis of the tool in the joining step is inclined with respect to the direction perpendicular to the upper surface so as to approach the third end portion in the first extending direction as it goes from the rear end side to the front end side of the tool. A joining method. (Configuration 9) In the joining step, the tip portion of the rotated tool is run along the end surface on the second member side of the first end portion. The joining method according to Configuration 8. (Configuration 10) The joining method according to Configuration 9, wherein in the joining step, the rotational direction of the tool on the front side where the tool travels is the direction from the second member toward the first member. (Configuration 11) In the joining step, when the apex angle of the conical shape of the tip of the tool is θc and the angle formed by the perpendicular to the upper surface of the first member and the central axis is θt, the relationship -5 < θt - (180 - θc)÷2 < 5 holds. The joining method according to any one of Configurations 7 to 10. (Configuration 12) Before the joining step, the second member has been bent along a bending line. In the joining step, The first member and the second member are placed on a backing provided with a recess. The recess is located below a part of the second member. The second member has a fourth end portion located on the side opposite to the first member side. The position of the bending line in the first extending direction is between the position of the opening edge on the fourth end portion side of the second member in the first extending direction of the recess and the position of the outer peripheral end on the fourth end portion side of the second member in the first extending direction of the conical tip portion. The joining method according to any one of Configurations 7 to 11. (Configuration 13) The first metal element is aluminum. The second metal element is copper. The joining method according to any one of Configurations 1 to 12. (Configuration 14) The first metal element is magnesium. The second metal element is aluminum. The joining method according to any one of Configurations 1 to 12. (Configuration 15) The first metal element is iron. The second metal element is titanium. The joining method according to any one of Configurations 1 to 12. (Configuration 16) The first metal element is nickel. The joining method according to any one of Configurations 1 to 12, wherein the second metal element is titanium. (Configuration 17) The first metal element is silver, The joining method according to any one of Configurations 1 to 12, wherein the second metal element is copper. (Configuration 18) The joining method according to any one of Configurations 1 to 17, wherein the solidus temperature of the first member is lower than the solidus temperature of the second member. (Configuration 19) A joining apparatus for joining a plate-shaped first member mainly composed of a first metal element and a plate-shaped second member mainly composed of a second metal element having a melting point higher than the melting point of the first metal element and having a eutectic point with the first metal element, A tool having a conical tip, A machining unit that holds and rotates the tool, An angle changing unit that changes the angle of the tool center axis with respect to the first member and the second member, A controller that controls the machining unit, Comprising, The controller causes the machining unit to perform a pressing operation of pressing the second end portion of the second member stacked on the first end portion of the first member toward the first member by the tip portion of the rotated tool, The upper surface of the first member extends in a first extending direction, The first member has a third end portion located on the opposite side of the second member in the first extending direction, During the pressing operation, the central axis of the tool is inclined with respect to the direction perpendicular to the upper surface of the first member so as to approach the third end portion in the first extending direction from the rear end side of the tool to the tip side of the tool by the angle changing unit. Joining device.

[0094] According to the embodiment, a joining method capable of more reliably joining members having different melting points of materials can be provided.

[0095] In this specification, "vertical" and "parallel" include not only strict verticality and strict parallelism, but also, for example, variations in the manufacturing process, and it is sufficient if they are substantially vertical and substantially parallel.

[0096] As described above, several embodiments of the present invention have been illustrated. However, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, changes, etc. can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof. Further, the above-described embodiments can be implemented in combination with each other.

Description of Reference Numerals

[0097] 11: First end 12: Second end 13: Third end 14: Fourth end 101: First member 101a: Upper surface 102: Second member 102a: One end 102b: The other end 102c: Upper surface 102d: Central portion 102e: Bent portion 103: Generation layer 111a: Joint surface 200: Backing 200a: Recess 201: Holding portion 300: Joining device 301: Tool 301a: Central axis 301b: Base 301c: Tip 301f: Traveling front surface 302: Stage 303: Processing portion 304: Moving portion 305: Frame 306: Controller 307: Angle change part C1: Contact surface Dm, Dm1, Dm2: Travel direction Dr: Rotation direction Dr1, Dr2: Direction EP1: First end point EP2: Second end point H1: Height H2: Height L: Distance L1: Bending line P1: First position P2: Second position P200a, PL1, Pe1, Ps3: Positions Ps3: Outer peripheral end R: Distance SP1: First starting point SP2: Second starting point e1: Tip s1: Tip surface s2: Side surface T102: Thickness

Claims

1. A bonding method for bonding a plate-shaped first member mainly composed of a first metal element and a plate-shaped second member mainly composed of a second metal element having a melting point higher than that of the first metal element and having a eutectic point with the first metal element, comprising: a step of overlapping a second end portion of the second member on a first end portion of the first member; a bonding step of pressing the second end portion toward the first member by a frustum-shaped or conical tip portion of a rotating tool, and causing the tip portion of the rotating tool to travel along an end face on the second member side of the first end portion; wherein in the bonding step, a rotation direction of the tool on a front side where the tool travels is a direction from the second member toward the first member.

2. A bonding method for bonding a plate-shaped first member mainly composed of a first metal element and a plate-shaped second member mainly composed of a second metal element having a melting point higher than that of the first metal element and having a eutectic point with the first metal element, comprising: a step of overlapping a second end portion of the second member on a first end portion of the first member; a first step of pressing the second end portion toward the first member by a tip portion of a rotating tool, and causing the tip portion of the rotating tool to travel toward one end of the second member; a second step of pressing the second end portion toward the first member by the tip portion of the rotating tool, and causing the tip portion of the rotating tool to travel toward the other end opposite to the one end of the second member; wherein the bonding method is provided.

3. In the first step, a rotation direction of the tool on a front side where the tool travels is a direction from the second member toward the first member; in the second step, a rotation direction of the tool on a front side where the tool travels is a direction from the second member toward the first member. The bonding method according to claim 2.

4. In the first step, the rotating tool starts traveling from a first starting point toward the one end; in the second step, the rotating tool starts traveling from a second starting point toward the other end; a position of the second starting point in a first direction from the other end toward the one end is between a position of the first starting point in the first direction and a position of the one end in the first direction. The bonding method according to claim 2 or 3.

5. The upper surface of the portion of the second member other than the end portion related to the joining with the first member is located at a first height before the joining step, In the joining step, the position of the tip of the tool in the thickness direction is within a range of within 20% of the thickness of the second member with respect to the first height. The joining method according to any one of claims 1 to 3.

6. The end of the first member on the second member side is located at a first position in a plane along the upper surface of the first member before the joining step, In the joining step, the position of the central axis of the tool is the first position or a position moved to the second member side from the first position, and below the central axis of the tool is the end of the first member or there is no first member. The joining method according to any one of claims 1 to 3.

7. The upper surface of the first member extends in a first extending direction, The first member has a third end portion located on the side opposite to the second member in the first extending direction, The central axis of the tool in the joining step is inclined with respect to the direction perpendicular to the upper surface so as to approach the third end portion in the first extending direction as it goes from the rear end side of the tool to the tip side of the tool. The joining method according to any one of claims 1 to 3.

8. A joining method for joining a plate-like first member mainly composed of a first metal element and a plate-like second member mainly composed of a second metal element having a melting point higher than that of the first metal element and having a eutectic point with the first metal element, A step of overlapping the second end portion of the second member on the first end portion of the first member, A joining step of pressing the second end portion toward the first member by a conical tip portion of a rotated tool, Comprising, The upper surface of the first member extends in a first extending direction, The first member has a third end portion located on the side opposite to the second member in the first extending direction, The central axis of the tool in the joining step is inclined with respect to the direction perpendicular to the upper surface so as to approach the third end portion in the first extending direction as it goes from the rear end side of the tool to the tip side of the tool. A joining method.

9. In the joining step, the tip portion of the rotated tool is run along the end surface of the first end portion on the second member side. The joining method according to claim 8.

10. The joining method according to claim 9, wherein in the joining step, the rotational direction of the tool on the front side where the tool travels is the direction from the second member toward the first member.

11. In the joining step, when the apex angle of the conical shape of the tip of the tool is θc and the angle formed by the perpendicular to the upper surface of the first member and the central axis is θt, the relationship of -5 < θt - (180 - θc)÷2 < 5 holds. The joining method according to any one of claims 8 to 10.

12. Before the joining step, the second member has been bent along a bending line. In the joining step, the first member and the second member are placed on a backing provided with a recess. The recess is located below a part of the second member. The second member has a fourth end portion located on the side opposite to the first member side. The position of the bending line in the first extending direction is between the position of the opening edge on the fourth end portion side of the second member in the first extending direction of the recess and the position of the outer peripheral end on the fourth end portion side of the second member in the first extending direction of the tip having a conical shape. The joining method according to any one of claims 8 to 10.

13. The first metal element is aluminum. The second metal element is copper. The joining method according to any one of claims 1 to 3.

14. The first metal element is magnesium. The second metal element is aluminum. The joining method according to any one of claims 1 to 3.

15. The first metal element is iron. The second metal element is titanium. The joining method according to any one of claims 1 to 3.

16. The solidus temperature of the first member is lower than the solidus temperature of the second member. The joining method according to any one of claims 1 to 3.

17. A joining device for joining a plate-shaped first member mainly composed of a first metal element and a plate-shaped second member mainly composed of a second metal element having a melting point higher than that of the first metal element and having a eutectic point with the first metal element, a tool having a conical tip, a processing unit that holds and rotates the tool, an angle changing unit that changes the inclination of the tool with respect to the first member and the second member, a controller that controls the processing unit, and is provided with. The controller causes the processing unit to perform a pressing operation of pressing the second end portion of the second member, which is overlapped on the first end portion of the first member, toward the first member by the tip portion of the rotated tool. The upper surface of the first member extends in a first extending direction. The first member has a third end portion located on the opposite side of the second member in the first extending direction. A bonding device in which, at the time of performing the pressing operation, a central axis of the tool is inclined with respect to a direction perpendicular to the upper surface so as to approach the third end portion in the first extending direction from the rear end side of the tool toward the tip end side of the tool by the angle changing portion.

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