Welding method and structure

Abstract

The present disclosure relates to a welding method and a structure. The laser output required for laser welding is reduced while suppressing the generation of welding defects. In the welding method, a first member and a second member are overlapped, laser is irradiated from the first member side to perform laser welding, and after a thin-walled portion having a thickness thinner than other regions is formed in a predetermined region of the first member, laser is irradiated from the first member side to the thin-walled portion.

Description

Technical Field

[0001] This invention relates to welding methods and structures. Background Technology

[0002] In recent years, it has been proposed that soft soldering and hard soldering be performed in cooling devices composed of components formed from aluminum materials such as aluminum or aluminum alloys in order to join the components formed from aluminum materials together.

[0003] For example, the liquid-cooled cooling device described in Patent Document 1 is configured such that an aluminum inlet header is brazed to one end face of the inflow section of the coolant flow body, an aluminum outlet header is brazed to one end face of the outflow section, and an aluminum intermediate header is brazed to the other end face of the coolant flow body.

[0004] In addition, as a method for joining components formed using aluminum material, patent document 2 proposes laser welding.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2016-161158

[0008] Patent Document 2: Japanese Patent Application Publication No. 4-270088 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] When manufacturing a cooling device that uses a liquid such as a coolant to cool an object, it is possible to overlap a first component and a second component formed from aluminum and join them by laser welding. For example, laser welding can be performed by irradiating the overlapping portion of the first and second components with a laser from the first component side. From an energy-saving perspective, it is preferable to reduce the laser output when performing laser welding. However, reducing the laser output may sometimes result in welding defects such as insufficient weld strength between the first and second components.

[0011] The purpose of this invention is to reduce the laser output required for laser welding while suppressing the generation of welding defects.

[0012] Technical solutions for solving the problem

[0013] Based on the above objectives, in the welding method of the present invention, a first component and a second component are overlapped, and laser welding is performed by irradiating a laser from the side of the first component. After forming a thin-walled portion with a thickness thinner than other regions in a predetermined area of ​​the first component, a laser is irradiated from the side of the first component toward the thin-walled portion.

[0014] Here, the feature is that the thin-walled portion is formed on the first component by stamping.

[0015] Furthermore, it is possible to make the thin-walled portion into a planar part that is irradiated by the laser.

[0016] Additionally, the laser is characterized in that it is irradiated in such a way that the diameter of the laser spot on the surface of the first member is smaller than the width of the thin-walled portion.

[0017] Additionally, the laser is irradiated in such a way that the width of the welded portion formed across the first and second components by the laser irradiation is smaller than the width of the thin-walled portion.

[0018] In addition, from another perspective, in the welding method of the present invention, a first component having a thin-walled portion with a thickness thinner than other regions is overlapped with a second component different from the first component, and laser welding is performed by irradiating the thin-walled portion from the side of the first component at the overlapping part of the first component and the second component.

[0019] Furthermore, from other perspectives, the structure of the present invention comprises: a first member having a thin-walled portion that is thinner than other regions; a second member that overlaps with the first member; and a welded portion formed at the location where the thin-walled portion of the first member overlaps with the second member, thereby joining the first member to the second member.

[0020] Invention Effects

[0021] According to the present invention, the laser output required for laser welding can be reduced while suppressing the generation of welding defects. Attached Figure Description

[0022] Figure 1 This is a perspective view of the liquid-cooled cooling device according to the embodiment.

[0023] Figure 2 This is a diagram showing the components that make up a liquid-cooled cooling device after disassembly.

[0024] Figure 3 yes Figure 1 Sectional view of section III-III.

[0025] Figure 4 yes Figure 1 A sectional view of section IV-IV.

[0026] Figure 5 Figures (a) to (b) illustrate the structure of inlet and outlet joints using other methods.

[0027] Figure 6 Figures (a) to (b) illustrate the laser welding process at the overlap between the inlet connector and the main body of the device.

[0028] Figure 7 Figures (a) to (b) illustrate the structure of the inlet and outlet connectors according to this embodiment.

[0029] Figure 8 Figures (a) to (b) illustrate the laser welding process at the overlap between the inlet connector and the main body of the device.

[0030] Label Explanation

[0031] 1…Liquid-cooled cooling device, 10…Main body of the device, 20…Change component, 30…Inlet connector, 31…Inlet pipe, 32…Retaining part, 34…Welding part, 40…Outlet connector, 41…Outlet pipe, 42…Retaining part, 44…Welding part, 321, 322, 421, 422…Thin-walled part. Detailed Implementation

[0032] Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings.

[0033] Figure 1 This is a perspective view of the liquid-cooled cooling device 1 according to the embodiment.

[0034] Figure 2 This is a diagram showing the components that make up the liquid-cooled cooling device 1 after disassembly.

[0035] Figure 3 yes Figure 1 Sectional view of section III-III.

[0036] Figure 4 yes Figure 1 A sectional view of section IV-IV.

[0037] The liquid-cooled cooling device 1 of the embodiment includes: a device body 10, which is an example of a second component through which coolant flows, and a changing component 20 that changes the flow direction of the coolant flowing in the device body 10. Furthermore, the liquid-cooled cooling device 1 includes: an inlet connector 30, which is an example of a first component, through which coolant flows from the outside of the device body 10 into the inside, and an outlet connector 40, which is another example of a first component, through which coolant flows from the inside of the device body 10 outwards.

[0038] (Main body of the device 10)

[0039] The main body 10 of the device is a component with a generally rectangular parallelepiped shape. The main body 10 is formed using an extrusion of JIS A6063 alloy, with the extrusion direction aligned with the long side. Additionally, as... Figure 1 As shown, the lengths of the long and short sides of the device body 10 are greater than the length in the vertical direction. Furthermore, the material type of JIS A6063 alloy can be T1, T5, or T6. Other material types are also possible, but the hardness of the device body 10 is preferably 42 (HV (Vickers hardness)) or higher.

[0040] Multiple through holes 11 are formed inside the main body 10, extending from one end along the long side to the other. In the liquid-cooled cooling device 1 of this embodiment, as... Figure 4 As shown, six through holes 11 are formed at the center near the front side and at the inner side of the center in the direction of the shorter side.

[0041] The six through holes 11 on the front side function as inflow-side flow paths 111 for coolant flowing in via the inlet connector 30 and before reaching the alteration member 20. Adjacent inflow-side flow paths 111 are separated by inflow sidewalls 111a.

[0042] On the other hand, the six through holes 11 on the inner side function as outflow-side flow paths 112 for coolant to flow through after passing through the alteration member 20 and before reaching the outlet connector 40. Adjacent outflow-side flow paths 112 are separated by outflow sidewalls 112a.

[0043] In addition, two recessed spaces 12 are formed in the center of the long side of the device body 10. One of the two spaces 12 is an inflow space 121 that is connected to the inflow flow path 111, and the other is an outflow space 122 that is connected to the outflow flow path 112.

[0044] The inflow-side space 121 is formed by removing the upper wall 13 and the inflow-side wall 111a, for example, through a cutting process. The lower space 121b is formed by a through hole 121a obtained by penetrating the upper wall 13 and removing the inflow-side wall 111a. Furthermore, in Figure 2 In the example shown, the inflow sidewall 111a is completely removed from top to bottom, but it is also possible that only a portion of the top side is removed and the remaining portion of the bottom side remains.

[0045] The outflow side space 122 is formed by removing the upper wall 13 and the outflow side wall 112a, for example, through a cutting process. The lower space 122b is formed by a through hole 122a obtained by penetrating the upper wall 13 and removing the outflow side wall 112a. Furthermore, in Figure 2In the example shown, the outflow sidewall 112a is completely removed from top to bottom, but it is also possible that only a portion of the top side is removed, while a portion of the bottom side remains.

[0046] like Figure 2 As shown, the through holes 121a and 122a are roughly rectangular in shape.

[0047] (Change component 20)

[0048] The modified components 20 are respectively disposed at both ends of the long side of the main body 10 of the device.

[0049] The modified component 20 is a component with a general rectangular shape and has a recess 21 formed on the end face of the device body 10. The inflow side flow path 111 and the outflow side flow path 112 are connected through the recess 21.

[0050] The modified component 20 is joined by laser welding to the mating part while the end face on the side of the device body 10 and the end face in the long side direction of the device body 10 are in contact.

[0051] The modified component 20 can be formed, for example, by deep drawing a strip made of a JIS A3000 series alloy of material category O. Alternatively, the modified component 20 can also be formed, for example, by machining a blank made of a JIS A3000 series alloy of material category H14 or a JIS A1000 series aluminum of material category H14.

[0052] (Inlet connector 30)

[0053] Figure 5 Figures (a) to (b) illustrate the structure of the inlet connector 30 and the outlet connector 40 according to this embodiment. Furthermore, as described below, the inlet connector 30 and the outlet connector 40 have the same basic structure. Figure 5 In (a) to (b), the reference numerals of the elements constituting the inlet connector 30 are shown, and the reference numerals of the elements constituting the outlet connector 40 are shown in (). Figure 5 (a) is a perspective view of the inlet connector 30 (outlet connector 40). Figure 5 (b) is Figure 5 (a) A sectional view of the VB-VB section.

[0054] The inlet connector 30 has an inlet pipe 31 that is cylindrical and arranged so that the centerline direction is vertical, and a retaining portion 32 that is plate-shaped and extends radially outward from the lower end of the inlet pipe 31 and holds the inlet pipe 31. In the inlet connector 30 of this embodiment, when viewed from above, the inlet pipe 31 is positioned offset inward from the center of the retaining portion 32 in the direction of the shorter side.

[0055] The retaining portion 32, when viewed from above, has a generally rectangular shape. Furthermore, the retaining portion 32 of this embodiment has a thin-walled portion 321 whose thickness (thickness in the vertical direction) is thinner than other areas. In this example, the thin-walled portion 321 is formed on the outer edge of the retaining portion 32, and the overall shape of the thin-walled portion 321 when viewed from above is rectangular. In other words, the outer edge of the retaining portion 32 of this embodiment is thinner than other areas. The thickness of the thin-walled portion 321 is, for example, in the range of 30% to 80% of the thickness of other areas of the retaining portion 32.

[0056] In addition, such as Figure 5 As shown in (a) to (b), the upper surface of the thin-walled portion 321 is a plane.

[0057] In the inlet connector 30, the inlet pipe 31 and the retaining part 32 are formed as a single unit. The inlet connector 30 is formed using a sheet of JIS A3003 alloy. Furthermore, the material category of JIS A3003 alloy can be material category H12 or material category H18. Alternatively, other material categories may be used, but the hardness of the retaining part 32 is preferably 35 (HV) or higher.

[0058] The inlet connector 30 is formed by stamping a sheet of JIS A3003 alloy. For example, an inlet tube 31 extending vertically from the center of a circular sheet is formed by deep drawing a circular sheet. Next, the circular sheet is cut into a rectangular shape by stamping or the like to form a retaining portion 32. Then, the outer edge of the retaining portion 32 is thinned by stamping to form a thin-walled portion 321, thereby obtaining a... Figure 5 The inlet connector 30 is shown in (a) to (b).

[0059] Then, the inlet connector 30 is joined by laser welding in a state where the lower end of the inlet pipe 31 faces the inflow-side space 121 of the device body 10 and the lower end face of the retaining part 32 rests on the upper surface of the device body 10 (the retaining part 32 and the device body 10 are overlapping). More specifically, for the inlet connector 30, in the state where the retaining part 32 and the device body 10 are overlapping, a welding part 34 is formed by irradiating the thin-walled part 321 with a laser from the retaining part 32 side, and the inlet connector 30 is joined by the welding part 34.

[0060] Furthermore, the laser welding process will be explained in detail later.

[0061] (Exit connector 40)

[0062] The outlet connector 40 is the same component as the inlet connector 30, having an outlet pipe 41 that is cylindrical and arranged such that the centerline direction is vertical, and a retaining portion 42 that is plate-shaped and extends radially outward from the lower end of the outlet pipe 41 and holds the outlet pipe 41. In the outlet connector 40 of this embodiment, when viewed from above, the outlet pipe 41 is positioned offset inward from the center of the retaining portion 42 in the direction of the shorter side.

[0063] The retaining portion 42 has a generally rectangular shape when viewed from above. Furthermore, the retaining portion 42 of this embodiment has a thin-walled portion 421 whose thickness (thickness in the vertical direction) is thinner than other areas. In this example, the thin-walled portion 421 is formed on the outer edge of the retaining portion 42, and the overall shape of the thin-walled portion 421 when viewed from above is rectangular. In other words, the outer edge of the retaining portion 42 of this embodiment is thinner than other areas. The thickness of the thin-walled portion 421 is, for example, in the range of 30% to 80% of the thickness of other areas of the retaining portion 32.

[0064] In addition, such as Figure 5 As shown in (a) to (b), the upper surface of the thin-walled portion 421 is a plane.

[0065] In the outlet connector 40, the outlet pipe 41 and the retaining part 42 are formed as a single unit. The outlet connector 40 is formed using a sheet of JIS A3003 alloy. Furthermore, the material category of JIS A3003 alloy can be material category H12 or material category H18. Alternatively, other material categories may be used, but the hardness of the retaining part 32 is preferably 35 (HV) or higher.

[0066] The outlet connector 40 is formed by stamping a sheet of JIS A3003 alloy. For example, an outlet pipe 41 extending vertically from the center of a circular sheet is formed by deep drawing a circular sheet. Next, the circular sheet is cut into a rectangular shape by stamping or the like to form a retaining portion 42. Then, the outer edge of the retaining portion 42 is thinned by stamping to form a thin-walled portion 421, thereby obtaining a... Figure 5 The outlet connector 40 is shown in the shape of (a) to (b).

[0067] Then, with the lower end of the outlet pipe 41 facing the outflow side space 122 of the device body 10 and the lower end face of the retaining part 42 resting on the upper surface of the device body 10 (with the retaining part 42 and the device body 10 overlapping), the outlet connector 40 is joined by laser welding. More specifically, for the outlet connector 40, with the retaining part 42 and the device body 10 overlapping, a welding part 44 is formed by irradiating the thin-walled part 421 with a laser from the retaining part 42 side, and the outlet connector 40 is joined by the welding part 44.

[0068] (Function of liquid cooling device 1)

[0069] In the liquid-cooled cooling device 1 configured as described above, the object to be cooled by the liquid-cooled cooling device 1 is placed on the upper surface of the device body 10, on the outer side in the longitudinal direction of the portion where the inlet connector 30 and the outlet connector 40 are provided. The object to be cooled can be exemplified as a battery pack 100 composed of a plurality of cuboid single cells 101.

[0070] Furthermore, in the liquid-cooled cooling device 1, the coolant flowing from the inlet pipe 31 of the inlet connector 30 into the inflow-side space 121 of the device body 10 reaches the recess 21 of the change member 20 through the inflow-side flow path 111. After reaching the recess 21 of the change member 20, the coolant reaches the outflow-side space 122 through the outflow-side flow path 112 and flows out from the outlet pipe 41 of the outlet connector 40. In this way, during the flow of the coolant in the inflow-side flow path 111 and the outflow-side flow path 112 of the device body 10, the coolant cools the battery pack 100 placed on the upper surface of the device body 10.

[0071] (Manufacturing method of liquid-cooled cooling device 1)

[0072] The liquid-cooled cooling device 1, configured as described above, is manufactured as follows.

[0073] With the end faces of both ends of the device body 10 along its long side and the end faces of the alteration member 20 on the device body 10 side in a state of contact, a laser is continuously irradiated onto the contact portion. In this way, the alteration member 20 is joined to both ends of the device body 10 along its long side by laser welding.

[0074] By irradiating the mating parts with a laser, a welded part 22 is formed at approximately the same position as the mating parts (see reference). Figure 3 ).

[0075] Furthermore, before joining the inlet connector 30 to the device body 10, a thin-walled portion 321 is formed in the retaining portion 32 of the inlet connector 30. Then, with the lower end of the inlet pipe 31 of the inlet connector 30 facing the inflow-side space 121 of the device body 10, the lower end face of the retaining portion 32 of the inlet connector 30 is placed on the upper surface of the device body 10 (the retaining portion 32 and the device body 10 overlap). Then, with the retaining portion 32 and the device body 10 overlapping, a laser is irradiated into the thin-walled portion 321 formed in the retaining portion 32, and the laser is irradiated around the inlet pipe 31. In this way, the inlet connector 30 is joined to the central portion of the device body 10 by laser welding.

[0076] By irradiating the thin-walled portion 321 of the retaining portion 32 with a laser, a weld portion 34 is formed at a position approximately the same as the irradiated position (see reference). Figure 1 , Figure 3 wait).

[0077] Similarly, before joining the outlet connector 40 to the device body 10, a thin-walled portion 321 is formed in the retaining portion 32 of the outlet connector 40. Then, with the lower end of the outlet pipe 41 of the outlet connector 40 facing the outflow side space 122 of the device body 10, the lower end face of the retaining portion 42 of the outlet connector 40 is placed on the upper surface of the device body 10 (the retaining portion 42 and the device body 10 overlap). Then, with the retaining portion 42 and the device body 10 overlapping, a laser is irradiated onto the thin-walled portion 421 formed in the retaining portion 42, and the laser is irradiated around the outlet pipe 41. In this way, the outlet connector 40 is joined to the central portion of the device body 10 by laser welding.

[0078] By irradiating the thin-walled portion 421 of the retaining portion 42 with a laser, a weld portion 44 is formed at a position approximately the same as the irradiated position (see reference). Figure 1 ).

[0079] (Thin-walled section formation process)

[0080] Next, the process of forming thin-walled portions 321 and 421 on the retaining portion 32 of the inlet connector 30 and the retaining portion 42 of the outlet connector 40 will be described in detail. Furthermore, since the inlet connector 30 and the outlet connector 40 have the same structure, the process of forming the thin-walled portion 321 on the retaining portion 32 of the inlet connector 30 will be described in detail here.

[0081] As described above, the thin-walled portion 321 can be formed by stamping. For example, a retaining portion 32 cut into a rectangular shape is clamped between a pair of molds having a predetermined shape and pressed. As a result, a thin-walled portion 321 with a thickness (thickness in the vertical direction) that is thinner than other areas is formed on the outer edge of the rectangular retaining portion 32.

[0082] The thickness of the retaining portion 32 of the inlet connector 30 is, for example, 0.9 mm to 1.2 mm. In this embodiment, the stamping process is performed such that the thickness of the thin-walled portion 321 is in the range of 30% to 80% of the thickness of other areas of the retaining portion 32.

[0083] If the thickness of the thin-walled portion 321 is excessively thin, the strength of the thin-walled portion 321 may decrease. In addition, if the thickness difference between the thin-walled portion 321 and other areas of the retaining portion 32 is small, the function of the thin-walled portion 321, which will be described later, may not be fully realized.

[0084] Here, the inlet connector 30 is formed using a sheet of JIS A3003 alloy. Furthermore, the retaining portion 32 of the inlet connector 30 may sometimes have uneven thickness, undulations, or misalignment depending on the state of the sheet material and the forming process. When an inlet connector 30 with such a retaining portion 32 is overlapped onto the device body 10, a gap may sometimes occur between the retaining portion 32 and the device body 10. Moreover, when a laser is irradiated onto the overlapped portion during the laser welding process described later, the weld strength between the retaining portion 32 and the device body 10 may be insufficient, sometimes resulting in welding defects.

[0085] In contrast, by forming a thin-walled portion 321 by stamping the holding portion 32 as in this embodiment, unevenness, undulation, and skewing in the thickness of the thin-walled portion 321 are easily eliminated. In other words, by forming the thin-walled portion 321, the area in the holding portion 32 where the thin-walled portion 321 is formed becomes flat. As a result, when laser is irradiated onto the overlapping portion during the laser welding process, welding defects are less likely to occur.

[0086] Details will be described later; the width of the thin-walled portion 321 (described later) Figure 6 In (a), W1) is preferably larger than the spot diameter of the laser used in the laser welding process.

[0087] Furthermore, this example illustrates the case where a thin-walled portion 321 is formed in the retaining portion 32 by stamping after the inlet pipe 31 and retaining portion 32 of the inlet connector 30 are formed. However, it is also possible to form the retaining portion 32 with the thin-walled portion 321 and the inlet pipe 31 simultaneously by a single stamping process.

[0088] In addition to stamping, the thin-walled portion 321 can also be formed by machining, for example. However, from the viewpoint of eliminating the unevenness, undulation, and skewing of the thickness of the holding portion 32, it is preferable to form the thin-walled portion 321 by stamping.

[0089] (Laser welding process)

[0090] Next, the laser welding process at the overlapping portion of the inlet connector 30 and outlet connector 40 with the device body 10 will be described in detail. Furthermore, since the inlet connector 30 and outlet connector 40 have the same structure, the laser welding process at the overlapping portion of the inlet connector 30 (holding part 32) with the device body 10 will be described in detail here.

[0091] Figure 6 Figures (a) to (b) illustrate the laser welding process at the overlapping part of the inlet connector 30 and the main body 10 of the device. Figure 6 (a) shows the state where laser L is irradiated in the forward overlapping region. Figure 6 (b) shows the weld 34 formed by irradiation with laser L. Furthermore, Figure 6 (a) to (b) are sectional views of the overlapping portion, corresponding to Figure 3 An enlarged view of the cross-sectional view of the liquid-cooled cooling device 1 shown.

[0092] During laser welding, laser L is irradiated from the laser head 151 of the laser device 150 toward the overlapping portion of the inlet connector 30 and the device body 10. In this embodiment, laser L is irradiated onto the overlapping portion from the holding portion 32 side. More specifically, as... Figure 6 As shown in (a), laser L is irradiated onto the overlapping portion from the upper surface side of the thin-walled portion 321 formed in the holding portion 32. As described above, the thin-walled portion 321 is formed into a rectangular shape along the outer edge of the holding portion 32. Therefore, laser L is irradiated while moving the laser head 151 along the shape of the thin-walled portion 321 relative to the overlapping portion; in other words, laser head 151 is moved along the outer edge of the holding portion 32. Thus, by irradiating laser L onto the thin-walled portion 321, a weld portion 34 is formed in a rectangular shape along the outer edge of the holding portion 32 in the overlapping portion.

[0093] By irradiating the thin-walled portion 321 of the holding portion 32 from the laser head 151 of the laser device 150 with laser L, the energy of the laser L is converted into heat. As a result, the base material of the holding portion 32 and the device body 10 constituting the overlapping portion melts itself and is then rapidly cooled. This rapid heating and cooling causes a microstructure change in the weld portion 34, which consists of a molten portion 34m that has solidified and a heat-affected portion 34h that has undergone microstructure change due to the welding heat. The heat-affected portion 34h consists of the heat-affected portion 32h of the holding portion 32 and the heat-affected portion 10h of the device body 10.

[0094] In this embodiment, by forming a thin-walled portion 321 in the holding portion 32 and irradiating the overlapping portion with laser L from the upper surface of the thin-walled portion 321, the intensity (laser output) of the laser required for laser welding of the overlapping portion can be reduced compared to the case where the holding portion 32 does not have a thin-walled portion 321.

[0095] That is, in order to ensure sufficient bonding strength between the inlet connector 30 and the device body 10, the depth H of the weld portion 34 (molten portion 34m) in the device body 10 needs to be at least a predetermined depth. In this embodiment, by irradiating the upper surface of the thin-walled portion 321 with laser L, the distance from the irradiation surface of laser L, i.e., the upper surface of the holding portion 32 (thin-walled portion 321), to the device body 10 is reduced. Therefore, even with a reduced laser output, a weld portion 34 (molten portion 34m) at a predetermined depth or greater can be formed in the device body 10. The depth H of the weld portion 34 (molten portion 34m) can, for example, be set to be at least the width W3 of the molten portion 34m at the interface between the device body 10 and the holding portion 32 (thin-walled portion 321).

[0096] Furthermore, by reducing the laser output, when the laser L is irradiated onto the overlapping portion, the strain caused by thermal contraction and deformation of the irradiated portion can be suppressed. This helps to prevent defects such as warping of the liquid-cooled cooling device 1.

[0097] Furthermore, by reducing the laser output, it is possible to suppress the formation of pores when a molten portion of 34m is formed in the overlapping part.

[0098] Furthermore, by irradiating the upper surface of the thin-walled portion 321 with laser L, the size of the heat-affected zone 34h (especially the size of the heat-affected zone 32h) in the weld portion 34 formed in the overlapping portion can be reduced. This reduces solidification and shrinkage associated with the formation of the heat-affected zone 34h. Consequently, it suppresses the decrease in strength of the overlapping portion and welding defects.

[0099] In this embodiment, as Figure 6 As shown in (a), it is preferable to irradiate the overlapping portion with laser L in such a way that the spot diameter of laser L is smaller than the width W1 of thin-walled portion 321. Here, the width W1 of thin-walled portion 321 is the distance between the outer and inner edges of the rectangular thin-walled portion 321 and the width of the thin-walled portion 321 in a cross-section after being cut by a plane perpendicular to the moving direction of the laser head 151 irradiating laser L onto thin-walled portion 321. In addition, the spot diameter of laser L is the diameter of the irradiation range of laser L on the irradiation surface (in this example, the upper surface of thin-walled portion 321) when laser L is irradiated onto the irradiation surface of the irradiated laser L. The spot diameter of laser L also varies depending on the material of inlet connector 30, the thickness of thin-walled portion 321, etc., and can be set to a range of 20 μm to 80 μm for example.

[0100] In addition, in this embodiment, such as Figure 6As shown in (b), it is preferable to set the laser output, etc., so that the width W2 of the molten portion 34m on the surface of the thin-walled portion 321 is smaller than the width W1 of the thin-walled portion 321. The laser output also varies depending on the material of the inlet connector 30, the thickness of the thin-walled portion 321, the spot diameter of the laser L, etc. However, in the case of a laser device 150 using a fiber laser, a spot diameter of 50 (μm), using nitrogen (N2) as an inert gas, and setting the focal point to be consistent with the material surface, the energy obtained by dividing the laser output by the laser's moving speed can be set to a range of 10 J / mm to 30 J / mm.

[0101] Furthermore, the laser source of the laser device 150 is not particularly limited. Examples include YAG lasers, CO2 lasers, fiber lasers, disk lasers, and semiconductor lasers. Additionally, the irradiation direction of the laser L can be orthogonal to the surface of the holding portion 32 of the overlapping portion, or it can be a direction inclined relative to the orthogonal direction.

[0102] (Other methods regarding thin-walled sections)

[0103] Next, other methods of forming thin-walled portions in the inlet connector 30 or outlet connector 40 will be described. In the example above, the outer edge of the retaining portion 32 (retaining portion 42) of the inlet connector 30 (outlet connector 40) is thinned to form a thin-walled portion 321 (thin-walled portion 421), but it is not limited to this.

[0104] Figure 7 Figures (a) to (b) illustrate the structure of the inlet connector 30 and outlet connector 40 using other methods. Figure 7 In (a) to (b), the reference numerals of the elements constituting the inlet connector 30 are shown, and the reference numerals of the elements constituting the outlet connector 40 are shown in (). Figure 7 (a) is a perspective view of the inlet connector 30 (outlet connector 40). Figure 7 (b) is Figure 7 A sectional view of section VIIB-VIIB in (a).

[0105] in addition, Figure 8 Figures (a) to (b) illustrate the laser welding process at the overlapping part of the inlet connector 30 and the main body 10 of the device. Figure 8 (a) shows the state where laser L is irradiated in the forward overlapping region. Figure 8 (b) shows the weld 34 formed by irradiation with laser L. Furthermore, Figure 8 (a) to (b) are sectional views of the overlapping portion, corresponding to Figure 3 An enlarged view of the cross-sectional view of the liquid-cooled cooling device 1 shown.

[0106] Here, regarding and Figure 5 (a)~(b) Figure 6 The inlet connectors 30 shown in (a) to (b) have the same structure and use the same reference numerals, so detailed descriptions are omitted.

[0107] like Figure 7 As shown in (a) to (b), the retaining portion 32 of the inlet connector 30 has a groove-shaped thin-walled portion 322 extending in a rectangular shape along its outer edge. Figure 7 As shown in (b), the cross-sectional shape of the thin-walled portion 322 becomes a trapezoidal shape that narrows in width from top to bottom and has a flat bottom surface. Furthermore, in Figure 7 In the inlet connector 30 shown in (a) to (b), the thickness (thickness in the vertical direction) at the bottom surface of the thin-walled portion 322 is thinner than that in other areas.

[0108] The thin-walled portion 322 can be formed by stamping in the same way as the thin-walled portion 321. For example, the retaining portion 32, which is cut into a rectangular shape, is clamped between a pair of molds having a predetermined shape and pressed. As a result, a groove-shaped thin-walled portion 322 is formed on the outer edge of the rectangular retaining portion 32.

[0109] Then, after the overlapping portion of the inlet connector 30 and the device body 10 is joined by laser welding, laser L is irradiated from the laser head 151 of the laser device 150. Specifically, as Figure 8 As shown in (a), for the overlapping portion, laser L is irradiated onto the bottom surface of the thin-walled portion 322 from the upper surface side. As described above, the thin-walled portion 322 is formed into a rectangular shape along the outer edge of the holding portion 32. Therefore, for the overlapping portion, laser L is irradiated while the laser head 151 is moved along the shape of the thin-walled portion 322. Thus, by irradiating laser L onto the thin-walled portion 321, a weld portion 34 is formed in a rectangular shape along the outer edge of the holding portion 32 in the overlapping portion.

[0110] exist Figure 8 Similarly, in the manner shown in (a) to (b), by forming a groove-shaped thin-walled portion 322 in the holding portion 32 and irradiating the overlapping portion with laser L from the upper surface of the thin-walled portion 322, the intensity (laser output) of the laser required for laser welding of the overlapping portion can be reduced compared to the case where the holding portion 32 does not have a thin-walled portion 322.

[0111] Here, as Figure 8 As shown in (a), the overlapping portion is preferably irradiated with laser L in such a way that the spot diameter of laser L is smaller than the width W4 of the bottom surface of thin-walled portion 322.

[0112] In addition, such as Figure 8As shown in (b), it is preferable to set the laser output, etc., so that the width W5 of the molten portion 34m at the bottom surface of the thin-walled portion 322 is smaller than the width W4 of the bottom surface of the thin-walled portion 322.

[0113] As explained above, the laser welding method of this embodiment overlaps an inlet connector 30 (outlet connector 40) as an example of a first component and a device body 10 as an example of a second component. Laser welding is performed by irradiating the inlet connector 30 (outlet connector 40) with laser L. After forming thin-walled portions 321, 322 (thin-walled portions 421, 422) with a thickness thinner than other regions in a predetermined area of ​​the inlet connector 30 (outlet connector 40), laser L is irradiated onto the thin-walled portions 321, 322 (thin-walled portions 421, 422) from the inlet connector 30 (outlet connector 40) side. Therefore, compared with the case where laser L is not irradiated onto the thin-walled portions 321, 322 (thin-walled portions 421, 422), the laser output required to join the inlet connector 30 (outlet connector 40) to the device body 10 can be reduced.

[0114] Furthermore, from another perspective, the laser welding method of this embodiment involves overlapping an inlet connector 30 (outlet connector 40), which is an example of a first component and has thin-walled portions 321, 322 (thin-walled portions 421, 422) that are thinner than other regions, with a device body 10, which is an example of a second component. Laser welding is performed by irradiating the thin-walled portions 321, 322 (thin-walled portions 421, 422) with a laser at the overlapping portion of the inlet connector 30 (outlet connector 40) and the device body 10. Therefore, compared to the case where the laser L is not irradiated onto the thin-walled portions 321, 322 (thin-walled portions 421, 422), the laser output required to join the inlet connector 30 (outlet connector 40) to the device body 10 can be reduced.

[0115] Furthermore, from other perspectives, the structure involved in this embodiment is a liquid-cooled cooling device 1, which includes: an inlet connector 30 (outlet connector 40) as an example of a first component, having thin-walled portions 321, 322 (thin-walled portions 421, 422) with a thickness thinner than other areas; a device body 10 as an example of a second component, overlapping with the inlet connector 30 (outlet connector 40); and a welding portion 34 (welding portion 44), formed at the portion where the thin-walled portions 321, 322 (thin-walled portions 421, 422) of the inlet connector 30 (outlet connector 40) overlap with the device body 10, thereby joining the inlet connector 30 (outlet connector 40) to the device body 10.

[0116] While the embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Various modifications and combinations are possible as long as they do not violate the spirit of the present invention.

Claims

1. A welding method for a cooling device, comprising overlapping a first component and a second component constituting the cooling device, and performing laser welding by irradiating the first component with a laser. The first component has a cylindrical inlet or outlet pipe and a plate-shaped retaining portion extending radially outward from one end of the inlet or outlet pipe to hold the inlet or outlet pipe. The second component has an internally formed through hole for coolant to flow from one end to the other, and a space recessed from its upper surface in communication with the through hole. After forming a thin-walled portion with a thickness thinner than other areas at the outer edge of the plate-shaped retaining portion of the first member, the lower end face of the retaining portion is placed on the upper surface of the second member with the end of one of the inlet pipe or outlet pipe facing the space, thereby overlapping the retaining portion with the second member. A laser is irradiated from the side of the first member toward the thin-walled portion, such that the depth of the weld portion formed across the first member and the second member by the irradiation of the laser is greater than or equal to the width of the weld portion at the interface between the first member and the second member.

2. The welding method according to claim 1, characterized in that, The thin-walled portion is formed in the first component by stamping.

3. The welding method according to claim 1, characterized in that, The thin-walled portion is formed into a plane as the part to be irradiated by the laser.

4. The welding method according to any one of claims 1 to 3, characterized in that, The laser is irradiated in such a way that the diameter of the laser spot on the surface of the first component is smaller than the width of the thin-walled portion.

5. The welding method according to any one of claims 1 to 3, characterized in that, The laser is irradiated in such a way that the width of the welded portion formed across the first and second components by the irradiation of the laser is smaller than the width of the thin-walled portion.

6. The welding method according to claim 4, characterized in that, The laser is irradiated in such a way that the width of the welded portion formed across the first and second components by the irradiation of the laser is smaller than the width of the thin-walled portion.

7. A welding method comprising laser welding a first component, which is used to constitute a cooling device and has a thin-walled portion having a thickness thinner than other regions, and a second component different from the first component. The first component has a cylindrical inlet or outlet pipe and a plate-shaped retaining portion extending radially outward from one end of the inlet or outlet pipe and holding the inlet or outlet pipe therein. The thin-walled portion is formed at the outer edge of the plate-shaped retaining portion. The second component has an internal through-hole for coolant to flow from one end to the other, and a space recessed from its upper surface in a manner communicating with the through-hole. With one end of the inlet or outlet pipe facing the space, the lower end face of the retaining portion is placed on the upper surface of the second member, and the retaining portion of the first member is overlapped onto the second member. Laser welding is performed by irradiating the thin-walled portion from the side of the first member at the location where the holding portion of the first member and the second member overlap, such that the depth of the weld portion formed across the first member and the second member by the irradiation of the laser is greater than or equal to the width of the weld portion at the interface of the first member and the second member.

8. A cooling device having a structure comprising: A first component has a cylindrical inlet or outlet pipe and a plate-shaped retaining portion extending radially outward from one end of the inlet or outlet pipe and holding the inlet or outlet pipe, wherein the outer edge of the plate-shaped retaining portion has a thin-walled portion that is thinner than other areas. The second component has a through hole for coolant to flow from one end to the other, and a space recessed from the upper surface in a manner communicating with the through hole. The retaining portion of the first component overlaps with the second component in such a manner that the end of one of the inlet pipe or outlet pipe faces the space. and A weld is formed at the location where the thin-walled portion of the first member overlaps with the second member, thereby joining the first member and the second member. The depth of the welded portion formed across the first component and the second component is greater than or equal to the width of the welded portion at the interface between the first component and the second component.

Images