Welded structure, welding method, and welding device

Abstract

For example, the present invention provides an improved and novel welding structure, welding method, and welding device that can more reliably obtain a required joining strength. [Solution] The welded structure includes, for example, a first member, a second member, and a weld that covers substantially the entire first end of the first member and the second end of the second member, and is arranged to span between a first edge of the first end opposite the second end in a second direction and a second edge of the second end opposite the first end in the second direction, wherein the ratio of the maximum height between the bottom located at the end of the weld opposite to the first direction and the top located at the end of the weld in the first direction to the maximum width in a direction intersecting the first direction of the weld is 0.7 or more and 1.5 or less.

Description

[Technical Field]

[0001] The present invention relates to a welded structure, a welding method, and a welding apparatus. [Background technology]

[0002] BACKGROUND ART A welding method for laser welding a plurality of wires such as rectangular wires is known (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6551961 Summary of the Invention [Problem to be solved by the invention]

[0004] In a welded structure in which a plurality of wires are laser-welded, it is important to ensure a required joint strength.

[0005] Therefore, one object of the present invention is to provide an improved novel welding structure, welding method, and welding apparatus that can more reliably obtain a required joining strength, for example. [Means for solving the problem]

[0006] The welded structure of the present invention includes, for example, a first member made of a copper-based material, having a linear shape, and having a first end in the longitudinal direction; a second member made of a copper-based material, having a linear shape, and having a second end in the longitudinal direction, the second end extending approximately parallel to a first direction that is the extension direction of the first end and arranged adjacent to the first end in a second direction that intersects with the first direction; and a weld that covers approximately the entire first end and the second end and is provided between a first edge of the first end opposite the second end in the second direction and a second edge of the second end opposite the first end in the second direction, wherein the ratio of the maximum height between a bottom located at the end of the weld opposite to the first direction and a top located at the end of the weld in the first direction to the maximum width of the weld in the direction intersecting the first direction is 0.7 or more and 1.5 or less.

[0007] In the welded structure, the oxygen concentration of the first member and the second member may be 50 ppm or more and 500 ppm or less.

[0008] In the welded structure, the concentration of the additive different from copper in the first member and the second member may be 15 ppm or more and 50 ppm or less.

[0009] The welded structure may contain at least one of the elements S, Fe, Ag, Sn, Ni, Pb, Zn, As, Se, and Sb as the additive.

[0010] In the welded structure, the first edge extends linearly in a direction intersecting the first direction and the second direction, and the second edge extends linearly in a direction intersecting the first direction and the second direction. When viewed in the opposite direction to the first direction, a ratio of the deviation of the apex relative to the intersection position of a first diagonal line connecting an end of the first edge in a third direction intersecting the first direction and the second direction and an end of the second edge in the opposite direction to the third direction, and a second diagonal line connecting the end of the first edge in the opposite direction to the third direction and the end of the second edge, to the longer of the first diagonal line and the second diagonal line may be 0.25 or less.

[0011] The welding method of the present invention includes, for example, a first step of arranging the first end and the second end so that they are adjacent to each other in the second direction, and a second step of forming the welded portion by irradiating laser light toward at least one of the first end and the second end after the first step.

[0012] In the welding method, in the second step, an inert gas at 80° C. or higher and 250° C. or lower may be supplied toward at least one of the first end portion and the second end portion.

[0013] In the welding method, the flow rate of the inert gas supplied in the second step may be 5 [l / min] or more and 100 [l / min] or less.

[0014] In the welding method, the inert gas may be supplied from a plurality of locations that are spaced apart from the intersection position and are rotationally symmetrical approximately n times (n is an integer of 2 or more) around the intersection position when viewed in the direction opposite to the first direction, toward a virtual line extending in the first direction that includes an intersection position between a first diagonal line connecting an end of the first edge in a third direction that intersects the first direction and the second direction and an end of the second edge in the opposite direction to the third direction, and a second diagonal line connecting the end of the first edge in the opposite direction to the third direction and an end of the second edge in the third direction.

[0015] In the welding method, the laser light may include laser light having a wavelength of 800 [nm] or more and 1200 [nm] or less.

[0016] In the welding method, the laser light may include laser light having a wavelength of 300 nm or more and 600 nm or less.

[0017] The welding device of the present invention includes, for example, a laser device that outputs laser light, and an optical head that irradiates the laser light output from the laser device toward the first end or the second end.

[0018] The welding device may include a gas nozzle that supplies an inert gas toward the first end or the second end. [Effects of the Invention]

[0019] According to the present invention, for example, it is possible to provide a novel welding structure, welding method, and welding device that make it possible to more reliably obtain a required joint strength. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a schematic diagram illustrating an exemplary configuration of a welding device according to an embodiment. [Figure 2] FIG. 2 is an exemplary schematic side view of a wire before being welded by the welding method of the embodiment. [Figure 3] FIG. 3 is an exemplary schematic plan view of the wire rod of FIG. [Figure 4] FIG. 4 is an exemplary schematic side view of a welded structure obtained by the welding method of the embodiment. [Figure 5] FIG. 5 is an exemplary schematic plan view of the welded structure of FIG. [Figure 6] FIG. 6 is a table showing a plurality of parameters and strength (joint strength) when a plurality of samples of welded structures are manufactured by the welding method of the embodiment. [Figure 7]FIG. 7 is an exemplary schematic side view of a welded structure obtained by the welding method of the embodiment. [Figure 8] FIG. 8 is an exemplary schematic plan view of the contact structure of FIG. [Figure 9] FIG. 9 is a schematic plan view showing an example in which gas is supplied from a plurality of locations in the welding method according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0021] Exemplary embodiments and modifications of the present invention are disclosed below. The configurations of the embodiments and modifications shown below, as well as the actions and results (effects) brought about by these configurations, are merely examples. The present invention can also be realized by configurations other than those disclosed in the following embodiments and modifications. Furthermore, according to the present invention, it is possible to obtain at least one of the various effects (including derivative effects) obtained by the configurations.

[0022] The following embodiments and modifications have similar components, and in the following description, the same reference numerals will be used to designate the similar components, and redundant explanations may be omitted.

[0023] In each figure, the direction X is represented by an arrow X, the direction Y is represented by an arrow Y, and the direction Z is represented by an arrow Z. The directions X, Y, and Z intersect and are perpendicular to each other. The Z direction is the direction in which the multiple members that become the wires 21 and 22 extend. Note that the Z direction is approximately vertically upward, but may be inclined relative to the vertically upward direction.

[0024] In this specification, ordinal numbers are given for convenience to distinguish between parts, portions, directions, etc., and do not indicate priority or order.

[0025] [Welding equipment] Fig. 1 is a diagram showing a schematic configuration of a laser welding apparatus 100 according to an embodiment. As shown in Fig. 1, the laser welding apparatus 100 includes laser devices 111 and 112, an optical head 120, an optical fiber 130, a control device 140, a drive mechanism 150, and a gas supply mechanism 160. The laser welding apparatus 100 is an example of a welding apparatus.

[0026] The laser welding apparatus 100 irradiates laser light L onto ends of wires 21 and 22 to be laser welded. The energy of the laser light L partially melts the ends of the wires 21 and 22, and then the ends are cooled and solidified to form a welded portion 23. As a result, a welded structure 20 is formed in which the plurality of wires 21 and 22 are joined via the welded portion 23. The laser welding apparatus 100 is an example of an apparatus for welding the wires 21 and 22. Note that the laser welding apparatus 100 may also form a welded structure by welding three or more wires. The wire 21 is an example of a first member, and the wire 22 is an example of a second member.

[0027] The wires 21 and 22 are made of a copper-based material such as oxygen-free copper or a copper alloy. The wires 21 and 22 may be made of the same material or different materials. The wires 21 and 22 are, for example, core materials of conductors such as segment coils of a rotating electrical machine, but are not limited to this.

[0028] When welding the wires 21 and 22, first, as shown in Fig. 1, the ends of the wires 21 and 22 in the longitudinal direction (Z direction) are arranged side by side in the X direction (first step). Next, laser beam L is irradiated from the laser welding device 100 toward at least one of the adjacent ends to form a weld 23 (second step). At this time, the laser beam L is irradiated substantially along the opposite direction to the Z direction.

[0029] The laser devices 111 and 112 each have a laser oscillator and are configured to be able to output laser light with a power of several kW, for example. The laser devices 111 and 112 may also be configured to have a plurality of semiconductor laser elements therein and to be able to output multimode laser light with a power of several kW as the total output of the plurality of semiconductor laser elements. The laser devices 111 and 112 may also have various laser light sources, such as a fiber laser, a YAG laser, a disk laser, or a semiconductor laser element.

[0030] The laser device 111 outputs a first laser beam having a wavelength of 800 nm or more and 1200 nm or less. The output of the laser device 111 is, for example, 3000 W, but is not limited to this. The laser device 111 may also be referred to as a first laser device.

[0031] On the other hand, the laser device 112 outputs a second laser light having a wavelength of 300 nm or more and 600 nm or less. The output of the laser device 112 is, for example, 700 W, but is not limited to this. The laser device 112 may also be referred to as a second laser device.

[0032] Furthermore, each of the laser devices 111 and 112 may output a continuous wave of laser light or a pulse of laser light.

[0033] The optical fiber 130 guides the laser beams output from the laser devices 111 and 112 to the optical head 120 .

[0034] The optical head 120 is an optical device for irradiating the ends 21 a, 22 a of the wire rods 21, 22 with laser light including the first laser light input from the laser device 111 and the second laser light input from the laser device 112. This configuration enables faster melting and, therefore, welding to be performed by keyhole-type melting with the first laser light, while suppressing the generation of spatters and blowholes through thermal conduction-type melting with the second laser light. In other words, high-quality and fast welding of the ends 21 a, 22 a can be performed.

[0035] 1, the optical head 120 includes a collimating lens 121, a condensing lens 122, a mirror 123, and a filter 124. The collimating lens 121, the condensing lens 122, the mirror 123, and the filter 124 may also be referred to as optical components.

[0036] The optical head 120 is configured to be able to change its position relative to the wires 21 and 22 in order to scan the surface of the wires 21 and 22 or the welded portion 23 after irradiating it with laser light. Note that scanning with the laser light L may be achieved by at least one of movement of the optical head 120, movement of the wires 21 and 22, and change in the emission direction of the laser light beam from the optical head 120. The optical head 120 may also include a laser scanner such as a galvanometer scanner.

[0037] The collimating lenses 121 (121-1, 121-2) each collimate the laser light input via the optical fiber 130. The collimated laser light becomes parallel light.

[0038] The mirror 123 reflects the first laser light that has been collimated by the collimator lens 121-1. The first laser light reflected by the mirror 123 travels in the opposite direction of the Z direction toward the filter 124. Note that in a configuration in which the first laser light is input to the optical head 120 so as to travel in the opposite direction of the Z direction, the mirror 123 is not necessary.

[0039] Filter 124 is a high-pass filter that transmits the first laser light and reflects but does not transmit the second laser light. The first laser light passes through filter 124 and travels in the opposite Z direction toward condenser lens 122. On the other hand, filter 124 reflects the second laser light that has been collimated by collimator lens 121-2. The second laser light reflected by filter 124 travels in the opposite Z direction toward condenser lens 122.

[0040] The condenser lens 122 condenses the first laser light and the second laser light as parallel light, and outputs the laser light L as output light.

[0041] The optical head 120 also has a DOE 125 (diffractive optical element) between the collimator lens 121-1 and the mirror 123. The DOE 125 can appropriately shape the beam of the first laser light. The DOE 125 is an example of a beam shaper. Note that the optical head 120 does not necessarily have to have the DOE 125.

[0042] Furthermore, the laser welding apparatus 100 includes a control device 140 , a driving mechanism 150 , and a gas supply mechanism 160 .

[0043] The control device 140 controls the operation of the laser devices 111 and 112, the drive mechanism 150, the gas supply mechanism 160, the laser scanner, etc. The control device 140 is a computer and includes a controller, a main memory, an auxiliary memory, etc. The controller is, for example, a processor (circuit) such as a CPU (central processing unit). The main memory is, for example, a RAM (random access memory) or a ROM (read only memory). The auxiliary memory is, for example, a non-volatile memory device such as an SSD (solid state drive) or an HDD (hard disk drive).

[0044] The driving mechanism 150 changes the relative position of the optical head 120 with respect to the wires 21 and 22. The driving mechanism 150 includes, for example, a rotation mechanism such as a motor, a speed reduction mechanism that reduces the rotation output of the rotation mechanism, and a motion conversion mechanism that converts the rotation reduced by the speed reduction mechanism into linear motion. The control device 140 can control the driving mechanism 150 so that the relative position of the optical head 120 with respect to the wires 21 and 22 in the X, Y, and Z directions changes.

[0045] The gas supply mechanism 160 supplies an inert gas G, such as N, toward the ends 21 a, 22 a or the welded portion 23 through piping and a gas nozzle 161. The inert gas G is discharged at a predetermined flow rate from a discharge port 161 a at the tip of the gas nozzle 161. Note that the inert gas G is not limited to N.

[0046] [Welding method] 2 is a side view showing the state of wire rods 21, 22 before being welded. Wire rods 21, 22 each extend substantially parallel to each other substantially along the Z direction and have Z-direction end portions 21a, 22a. End portions 21a, 22a extend across the Z direction. That is, end portions 21a, 22a extend in both the X direction and the Y direction. The Z direction is the longitudinal direction of wire rods 21, 22 and is an example of a first direction. Furthermore, end portion 21a is an example of a first end portion, and end portion 22a is an example of a second end portion.

[0047] The wire rods 21 and 22 are adjacent to each other in the X direction, which intersects with the Z direction, and are lined up in the X direction. A gap g is formed between the wire rods 21 and 22. The size of the gap g is equal to or greater than 0. That is, the wire rods 21 and 22 may be in at least partial contact with each other. The X direction is an example of a second direction.

[0048] As shown in FIG. 2, the laser light L is scanned in a direction intersecting the Z direction while being irradiated onto the end portion 21a.

[0049] FIG. 3 is a plan view showing the state of the wire rods 21 and 22 before they are welded. FIG. 3 shows trajectories P1 and P2 along which the laser beam L is scanned while being irradiated. As shown in FIG. 3, the laser beam L is irradiated onto at least one of the end portions 21a and 22a, and is not irradiated onto the gap g. The irradiation area of ​​the laser beam L at the end portions 21a and 22a is not limited to that shown in FIG. 3. For example, the irradiation area of ​​the laser beam L may be an area of ​​one of the end portions 21a and 22a that is closer to the other end portion than the center of the end portion 21a and 22a in the X direction. The trajectories P1 and P2 of the laser beam L are not limited to the example shown in FIG. 3.

[0050] Fig. 4 is a side view of a welded structure 20 obtained by the welding method of this embodiment, and Fig. 5 is a plan view of the welded structure 20. By irradiating the ends 21a, 22a with laser light L, the wires 21, 22 melt at the ends 21a, 22a, and a weld 23 is formed spanning the two ends 21a, 22a. The weld 23 is formed by cooling and solidifying a molten pool that has been formed spanning the two ends 21a, 22a.

[0051] The molten pool, which is a fluid metal material, has a shape that bulges convexly in the Z direction due to surface tension. Accordingly, the weld 23, which solidifies from the molten pool, also bulges convexly in the Z direction. As shown in FIGS. 4 and 5 , the weld 23 covers substantially the entire ends 21a and 22a and is provided so as to extend between the edge 21b of the end 21a and the edge 22b of the end 22a. In this case, the edge 21b is the edge of the end 21a located on the opposite side of the end 22a in the X direction (the end opposite the X direction in the example of FIGS. 4 and 5 ) and extends substantially linearly in the Y direction. On the other hand, the edge 22b is the edge of the end 22a located on the opposite side of the end 21a in the X direction (the end in the X direction in the example of FIGS. 4 and 5 ) and extends substantially linearly in the Y direction. The weld 23 also mechanically connects the two wires 21 and 22. When the two wires 21 and 22 are made of a conductive metal, the welded portion 23 electrically connects the two wires 21 and 22 together.

[0052] [Welding conditions] 6 is a table showing the values ​​of multiple parameters and strength (=breaking load / cross-sectional area, joint strength) when multiple samples of welded structure 20 are manufactured using the welding method of this embodiment. The load is a load acting in a direction (X direction and the direction opposite to the X direction) that pulls two end portions 21a, 22a away from each other, and the cross-sectional area is the sum of the cross-sectional area of ​​wire 21 and the cross-sectional area of ​​wire 22. The inventors actually manufactured multiple samples of welded structure 20 by varying the following parameters (1) to (5), and examined the strength. In FIG. 6, Examples 1 to 4 satisfy the strength conditions, and Comparative Examples 1 to 5 do not satisfy the strength conditions.

[0053] (1) Hmax / Wmax As shown in FIG. 4, Hmax is the maximum height between bottom portion 23b, located at the end of welded portion 23 opposite in the Z direction, and top portion 23a, located at the end of welded portion 23 in the Z direction. Also, as shown in FIG. 5, Wmax is the maximum width of welded portion 23 in a direction intersecting the Z direction. The ratio (Hmax / Wmax) is the ratio of Hmax to Wmax and may also be referred to as the aspect ratio of welded portion 23. Experiments, simulations, and the like have shown that the ratio (Hmax / Wmax) is preferably 0.7 or more and 1.5 or less. This is because, when the ratio (Hmax / Wmax) is less than 0.7, the cross-sectional area of ​​welded portion 23 becomes small, resulting in insufficient strength. On the other hand, when the ratio exceeds 1.5, welded portion 23 is likely to tilt or distort, ultimately resulting in insufficient strength. The position where the welded portion 23 has the maximum height Hmax is not limited to the position shown in FIG. 4, and the position where the welded portion 23 has the maximum width Wmax is not limited to the position shown in FIG.

[0054] (2) Oxygen concentration in wire (non-welded part) [ppm] Experiments have shown that the oxygen concentration in the wires 21 and 22 (non-welded portions) is preferably 50 ppm or more and 500 ppm or less. This is because, if the oxygen concentration is less than 50 ppm, the ratio (Hmax / Wmax) becomes less than 0.7, resulting in insufficient strength, and, if the oxygen concentration exceeds 500 ppm, voids are generated in the welded portion 23 formed by melting the wires 21 and 22, reducing the cross-sectional area of ​​the welded portion 23 intersecting the Z direction, resulting in insufficient strength.

[0055] (3) Additive concentration in wire rod (non-welded part) [ppm] Experiments have shown that the additive concentration in the wires 21 and 22 (non-welded portions) is preferably 15 ppm or more and 50 ppm or less. This is because, if the additive concentration is less than 15 ppm, the ratio (Hmax / Wmax) becomes less than 0.7, resulting in insufficient strength. If the additive concentration is more than 50 ppm, the wires 21 and 22 have high electrical resistance, are not suitable as conductive materials, and the concentration of the additive elements leads to a brittle metal structure, resulting in insufficient strength. Examples of additives include S, Fe, Ag, Sn, Ni, Pb, Zn, As, Se, and Sb. Adding these additives can improve various properties of the wires 21 and 22, such as corrosion resistance, impact resistance, wear resistance, and pressure resistance.

[0056] (4) Temperature of the supplied gas Experiments have shown that the temperature of the supplied inert gas G is preferably 80°C or higher and 250°C or lower. This is because if the temperature is lower than 80°C, the ratio (Hmax / Wmax) will be less than 0.7, resulting in insufficient strength, and if the temperature exceeds 250°C, the coating near the weld 23 will deteriorate and will no longer be able to maintain its insulation properties.

[0057] (5) Flow rate of gas supplied Experiments have shown that the flow rate of the supplied inert gas G is preferably 5 l / min or more and 100 l / min or less. This is because if the flow rate is less than 5 l / min, oxygen in the air and other factors will cause voids to form in the welded portion 23, reducing the cross-sectional area of ​​the welded portion 23 and resulting in insufficient strength. If the flow rate exceeds 100 l / min, the wind pressure of the inert gas G will cause the welded portion 23 to tilt or distort, which will likely result in insufficient strength.

[0058] [Weld distortion tolerance] FIG. 7 is a side view of a welded structure 20 different from those shown in FIGS. 4 and 5 obtained by the welding method of this embodiment, and FIG. 8 is a plan view of the welded structure 20 of FIG. 7. As shown in FIGS. 7 and 8, the welded portion 23 may not extend straight along the Z direction but may be distorted. To evaluate the change in strength of the welded portion 23 due to distortion, the distortion of the welded portion 23 is represented here by the deviation δ of the apex 23a of the welded portion 23 from the imaginary line VL. The apex 23a is the end of the welded portion 23 in the Z direction. The imaginary line VL is a straight line that passes through point CP (see FIG. 8) and extends in the Z direction. As shown in FIG. 8 , point CP is defined as the intersection of a diagonal line D1 connecting corner 21c1 of wire 21 and corner 22c2 of wire 22 and a diagonal line D2 connecting corner 21c2 of wire 21 and corner 22c1 of wire 22 in a plan view of end portions 21a and 22a viewed in opposite directions in the Z direction. Here, corner 21c1 is located at the end of edge 21b in the Y direction, and corner 22c2 is located at the end of edge 22b in the opposite direction in the Y direction. Also, corner 21c2 is located at the end of edge 21b in the opposite direction in the Y direction, and corner 22c1 is located at the end of edge 22b in the Y direction. In this case, point CP can be said to be a point located approximately in the center of the two end portions 21a and 22a in a plan view. A state in which the deviation δ of the apex 23a from the virtual line VL is small can be said to indicate a state in which the welded portion 23 has little variation in strength against a shear force acting in a direction intersecting the Z direction. Through experimental research, the inventors have found that the ratio of the deviation δ to the length of the longer of the diagonals D1 and D2 is preferably 0.25 or less. In other words, when this ratio exceeds 0.25, the shear strength of the welded portion 23 against an external force acting in a direction intersecting the Z direction decreases. The diagonal line D1 is an example of a first diagonal line, and the diagonal line D2 is an example of a second diagonal line. The Y direction is an example of a third direction. Note that the form of distortion of the welded portion 23 is not limited to that shown in FIGS. 7 and 8 . The welded portion 23 may also be distorted (displaced) in a direction intersecting the Z direction other than the direction shown in FIGS. 7 and 8 (the opposite direction to the X direction).

[0059] [Gas nozzle] FIG. 9 is a plan view showing a configuration in which inert gas G is supplied to the ends 21a and 22a from multiple locations around them. As shown in FIG. 9, inert gas G may be supplied from multiple gas nozzles 161. In the example of FIG. 9, in a plan view seen in the opposite direction of the Z direction, inert gas G is supplied from multiple locations spaced apart from point CP and arranged in approximately n-times rotational symmetry (n is an integer greater than or equal to 2, 4 in the example of FIG. 9) around point CP. In this case, the tip (discharge port 161a) of the gas nozzle 161 is located on the circumference of an imaginary circle VC centered on point CP. If the gas nozzle 161 is positioned offset from point CP in a plan view, a relatively high flow rate of inert gas G may push the unsolidified molten pool with the inert gas G, resulting in a large offset δ. For example, if the multiple gas nozzles 161 are all positioned at positions offset in the X direction from point CP, there is a risk that the offset δ of the top 23a of the welded portion 23 in the opposite direction to the X direction will increase when the flow rate of the inert gas G is relatively large. In this regard, by arranging the gas nozzles 161 as shown in Figure 9, the force acting from the inert gas G can be counteracted, thereby preventing distortion of the welded portion 23 due to the force acting from the inert gas G. Note that Figure 9 is just an example, and the above n may be 2 or 3, or 5 or more.

[0060] As described above, in this embodiment, welded portion 23 is formed so that the ratio Hmax / Wmax is 0.7 or more and 1.5 or less. Furthermore, welded portion 23 is formed so that the ratio of the deviation of apex 23a from imaginary line VL to the length of the longer of diagonals D1, D2 is 0.25 or less. This embodiment can prevent a decrease in the joining strength of welded portion 23. In other words, a welded structure 20 having the required strength can be formed.

[0061] Furthermore, in this embodiment, by setting the oxygen concentration and the additive concentration of the wires 21 and 22 within the appropriate ranges described above, it is possible to prevent a decrease in the joining strength of the welded portion 23. In other words, it is possible to form a welded structure 20 having a required strength.

[0062] Furthermore, in this embodiment, supplying the inert gas under the appropriate conditions described above can prevent a decrease in the joining strength of the welded portion 23. In other words, a welded structure 20 having the required strength can be formed.

[0063] While the above describes exemplary embodiments and modifications of the present invention, these are merely examples and are not intended to limit the scope of the invention. The above embodiments and modifications can be implemented in various other forms, and various omissions, substitutions, combinations, and modifications can be made without departing from the spirit of the invention. Furthermore, the specifications of each configuration, shape, and the like (structure, type, direction, model, size, length, width, thickness, height, number, arrangement, position, material, etc.) can be modified as appropriate.

[0064] For example, when irradiating the laser beam, known wobbling, weaving, output modulation, etc. may be performed to adjust the surface area or volume of the molten pool.

[0065] Alternatively, two laser beams may be emitted simultaneously and in parallel to the first end and the second end. [Explanation of symbols]

[0066] 20... Welded structure 21...Wire rod (first member) 21a...End (first end) 21b...Edge (first edge) 21c1,21c2...corner 22...Wire rod (second member) 22a...End (second end) 22b...Edge (second edge) 22c1,22c2…corner 23...Welded section 23a...Top 23b…Bottom 100...Laser welding device (welding device) 111, 112...Laser device 120...Optical head 121, 121-1, 121-2...Collimating lenses 122...Condenser lens 123...Mirror 124...Filter 125…DOE 130...Optical fiber 140...Control device 150...Drive mechanism 160...Gas supply mechanism 161...Gas nozzle 161a...Discharge port CP…point (intersection position) D1...Diagonal (first diagonal) D2...Diagonal (Second diagonal) G: Inert gas g...gap Hmax: Maximum height L...laser light P1,P2…Trajectory Wmax…Maximum width VC...Virtual Circle VL...Virtual line X…direction (second direction) Y…direction (third direction) Z…direction (first direction) δ…deviation

Claims

1. a first member made of a copper-based material, having a linear shape, and having a first end portion in a longitudinal direction; a second member made of a copper-based material, having a linear shape, and having a second end portion in a longitudinal direction, the second end portion extending substantially parallel to a first direction that is an extension direction of the first end portion, and arranged adjacent to the first end portion in a second direction that intersects with the first direction; a weld portion that covers substantially the entirety of the first end portion and the second end portion and is provided between a first edge of the first end portion opposite the second end portion in the second direction and a second edge of the second end portion opposite the first end portion in the second direction; Equipped with A welded structure, wherein the ratio of the maximum height between a bottom portion located at an end of the weld in the opposite direction to the first direction and a top portion located at an end of the weld in the first direction to the maximum width of the weld in a direction intersecting the first direction is 0.7 or more and 1.5 or less.

2. 2. The welded structure according to claim 1, wherein the first member and the second member have an oxygen concentration of 50 ppm or more and 500 ppm or less.

3. 2. The welded structure according to claim 1, wherein the concentration of the additive other than copper in the first member and the second member is 15 ppm or more and 50 ppm or less.

4. The welded structure according to claim 3, wherein the additive contains at least one element selected from the group consisting of S, Fe, Ag, Sn, Ni, Pb, Zn, As, Se, and Sb.

5. the first edge extends like a line segment in a direction intersecting the first direction and the second direction, the second edge extends like a line segment in a direction intersecting the first direction and the second direction, When viewed in a direction opposite to the first direction, 2. The welded structure according to claim 1, wherein a ratio of a deviation of the apex with respect to an intersection position of a first diagonal line connecting an end of the first edge in a third direction intersecting the first direction and the second direction and an end of the second edge in the opposite direction to the third direction, and a second diagonal line connecting the end of the first edge in the opposite direction to the third direction and the end of the second edge, to a longer length of the first diagonal line or the second diagonal line is 0.25 or less.

6. A welding method for forming the welded structure according to any one of claims 1 to 5, a first step of arranging the first end portion and the second end portion adjacent to each other in the second direction; a second step of forming the welded portion by irradiating a laser beam toward at least one of the first end portion and the second end portion after the first step; A welding method comprising:

7. The welding method according to claim 6, wherein in the second step, an inert gas at a temperature of 80°C or higher and 250°C or lower is supplied toward at least one of the first end portion and the second end portion.

8. 8. The welding method according to claim 7, wherein the flow rate of the inert gas supplied in the second step is 5 [L / min] or more and 100 [L / min] or less.

9. 8. The welding method according to claim 7, wherein the inert gas is supplied from a plurality of locations that are spaced apart from the intersecting position and are rotationally symmetrical approximately n times (n is an integer of 2 or more) around the intersecting position when viewed in the direction opposite to the first direction, toward a virtual line that extends in the first direction and includes an intersecting position of a first diagonal line connecting an end of the first edge in a third direction that intersects the first direction and the second direction and an end of the second edge in the opposite direction to the third direction, and a second diagonal line connecting the end of the first edge in the opposite direction to the third direction and the end of the second edge in the third direction.

10. 7. The welding method according to claim 6, wherein the laser light includes laser light having a wavelength of 800 nm or more and 1200 nm or less.

11. The welding method according to claim 6, wherein the laser light includes laser light having a wavelength of 300 nm or more and 600 nm or less.

12. A welding device for forming the welded structure according to any one of claims 1 to 5, a laser device that outputs laser light; an optical head that irradiates the laser light output from the laser device toward the first end or the second end; A welding device comprising:

13. The welding device according to claim 12 , further comprising a gas nozzle for supplying an inert gas toward the first end or the second end.

Images