Manufacturing method of laminate

Abstract

To provide a technology for preferably welding a contact part between overlapped metal plates when the contact part is welded to manufacture a laminate.SOLUTION: A manufacturing method of a laminate in which an internal space is formed between a first metal plate and a second metal plate includes: accommodating the first metal plate in a recessed accommodation part; closing an opening of the accommodation part by the second metal plate while allowing the second metal plate to overlap with the first metal plate; reducing pressures of the internal space formed by overlapping the first metal plate and the second metal plate with each other and a closed space formed by closing the opening of the accommodation part; and welding the contact part between the first metal plate and the second metal plate.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a method for manufacturing a laminate in which an internal space is formed between metal plates. [Background technology]

[0002] One method for producing a laminate in which an internal space is formed between metal plates is to obtain the laminate by overlapping two metal plates and welding their contact portions. In such a method, it is preferable that the two overlapping metal plates are in close contact at the contact portion in order to ensure good welding of the contact portion.

[0003] One method for increasing the adhesion between metal plates is to clamp the two metal plates with a clamping jig, but in this method, the positioning of the clamping jig can limit the range of welding.

[0004] Therefore, for example, Patent Document 1 proposes a method in which two metal plates are stacked together to form an internal space between them, and the pressure in the internal space is reduced to increase the adhesive force between the metal plates. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 8-25068 Summary of the Invention [Problem to be solved by the invention]

[0006] However, if a gap is formed between two overlapping metal plates, for example, if the metal plates are undulated, it is conceivable that the method described in Patent Document 1 would allow outside air to enter through the gap, making it difficult to reduce the pressure in the internal space. If the internal space is not sufficiently reduced in pressure, it would be difficult to increase the adhesion between the metal plates, and there is a possibility that the contact portions of the metal plates would not be well welded.

[0007] One aspect of the present disclosure provides a technique for successfully welding contact portions when manufacturing a laminate by welding contact portions between overlapping metal plates. [Means for solving the problem]

[0008] One aspect of the present disclosure is a method for manufacturing a laminate in which an internal space is formed between a first metal plate and a second metal plate. The method for manufacturing a laminate includes the following steps (i) and (ii):

[0009] (i) A first metal plate is accommodated in a recessed accommodation portion, and the opening of the accommodation portion is closed with a second metal plate while the second metal plate is superimposed on the first metal plate.

[0010] (ii) Reducing the pressure in the internal space formed by overlapping the first metal plate and the second metal plate and the closed space formed by closing the opening of the storage section, and welding the abutting portion between the first metal plate and the second metal plate.

[0011] According to this configuration, the adhesive strength at the contact portion between the first metal plate and the second metal plate can be increased, and therefore the contact portion can be well welded.

[0012] In one aspect of the present disclosure, the pressure in the internal space and the closed space may be reduced by sucking air through both a first communication portion that connects the internal space to the outside and a second communication portion that connects the closed space to the outside.

[0013] With this configuration, the bonding strength between the first metal plate and the second metal plate can be increased.

[0014] In one embodiment of the present disclosure, the second metal plate may have a curved outer periphery, and the outer periphery may abut against the inner surface of the housing portion to close the opening of the housing portion.

[0015] With this configuration, the adhesive force at the contact portion between the first metal plate and the second metal plate can be further increased.

[0016] In one aspect of the present disclosure, the outer circumferential portion may abut against the inner surface of the housing portion in a direction curved away from the first metal plate side inside the housing portion.

[0017] With this configuration, the adhesive strength at the contact portion between the first metal plate and the second metal plate can be further increased. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II of FIG. [Figure 3] FIG. [Figure 4] 1 is a top view of the pressure reducing device in a state in which the first metal plate and the second metal plate are arranged. FIG. [Figure 5] Fig. 5A is a cross-sectional view for explaining the placement step, and Fig. 5B is a cross-sectional view showing the state subsequent to Fig. 5A in the placement step. [Figure 6] FIG. 10 is a cross-sectional view illustrating a welding process. [Figure 7] FIG. 10 is another cross-sectional view illustrating the welding step. [Figure 8] FIG. 10 is a cross-sectional view illustrating a modified example of the second metal plate. [Figure 9] FIG. 10 is a cross-sectional view illustrating another modified example of the second metal plate. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings. [1. Structure of laminate] The laminate 1 shown in FIGS. 1 and 2 is a cooler in which an internal space 11 serving as a flow path for a refrigerant is formed between a first metal plate 20 and a second metal plate 30. The laminate 1 has a plate-like overall outer shape. The internal space 11 is continuously connected from an inlet end 12 to an outlet end 13. The inlet end 12 and the outlet end 13 are communication parts connecting the internal space 11 to the outside. The refrigerant flowing from the inlet end 12 into the internal space 11 flows through the internal space 11 and flows out from the outlet end 13 to the outside. The refrigerant flowing out from the outlet end 13 is cooled in a cooling part (not shown) and flows back into the internal space 11 from the inlet end 12. In other words, the internal space 11 functions as a flow path for circulating the refrigerant. The internal space 11 is connected to the outside only at the inlet end 12 and the outlet end 13.

[0020] The laminate 1 is mounted on, for example, an electric vehicle and used to cool the battery of the electric vehicle. Specifically, in the electric vehicle, the laminate 1 is arranged so that the first metal plate 20 faces and contacts the battery. Heat is exchanged between the refrigerant flowing through the internal space 11 and the battery, thereby cooling the battery.

[0021] The first metal plate 20 and the second metal plate 30 included in the laminate 1 are stacked and joined together. The first metal plate 20 and the second metal plate 30 are plate-shaped members made of metal. In this embodiment, the first metal plate 20 and the second metal plate 30 have a rectangular outer shape in a plan view.

[0022] The first metal plate 20 has a flat plate shape. Two through holes 21 are formed in the first metal plate 20, which function as the inlet end portion 12 and the outlet end portion 13 described above, respectively. The two through holes 21 penetrate the first metal plate 20 in the plate thickness direction. Each of the two through holes 21 is formed at a position that overlaps a groove portion 31 of the second metal plate 30, which will be described later, in a plan view.

[0023] The second metal plate 30 is a plate-like member in which a groove 31 is formed to form an internal space 11 between the second metal plate 30 and the first metal plate 20. The second metal plate 30 is formed to be slightly larger than the first metal plate 20 in a plan view. The second metal plate 30 is laminated on the first metal plate 20 so as to encompass the first metal plate 20 in a plan view. The second metal plate 30 is joined to the first metal plate 20 at a contact portion 32, which is a portion that contacts the first metal plate 20. The groove 31 is covered by the first metal plate 20. The space defined by the groove 31 and the first metal plate 20 corresponds to the internal space 11. As described above, the internal space 11 is continuously connected from the inlet end 12 to the outlet end 13. That is, the groove portion 31 is formed so as to extend seamlessly from the portion facing the through hole 21 of the first metal plate 20 that functions as the inlet end portion 12 to the portion facing the through hole 21 of the first metal plate 20 that functions as the outlet end portion 13.

[0024] In addition, the second metal plate 30 of this embodiment is formed so that the outer periphery 33 is curved along the entire periphery in a plan view. The outer periphery 33 is curved toward the opposite side to the first metal plate 20 side.

[0025] [2. Manufacturing method of laminate] A method for manufacturing the laminate 1 (specifically, a welding method for the laminate 1, which constitutes at least a part of the method for manufacturing the laminate 1) will be described with reference to FIGS. 3 to 7. The method for manufacturing the laminate 1 includes an arrangement step and a welding step. The arrangement step is a step of arranging the first metal plate 20 and the second metal plate 30 in a pressure reducing device 4. The welding step is a step of welding the abutting portion 32 of the first metal plate 20 and the second metal plate 30 while reducing the pressure of an internal space 11 formed between the first metal plate 20 and the second metal plate 30 and a closed space 56, which will be described later, in a state in which the first metal plate 20 and the second metal plate 30 are arranged in the pressure reducing device 4.

[0026] [2-1. Composition of pressure reducing device] First, the configuration of the pressure reducing device 4 will be described. 3, the pressure reducing device 4 includes a positioning jig 50 and at least one (three in this embodiment) vacuum pump 60. Note that the vacuum pump 60 is shown schematically in the drawing.

[0027] The positioning jig 50 is a jig for positioning the first metal plate 20 and the second metal plate 30. The positioning jig 50 is made of metal. The positioning jig 50 includes a base portion 51 and a frame portion 52.

[0028] The base portion 51 and the frame portion 52 form a recessed accommodation portion 53 for accommodating the first metal plate 20. Specifically, the base portion 51 forms the bottom surface of the inner surface of the accommodation portion 53. The base portion 51 in this embodiment has a rectangular parallelepiped shape. An upper surface 511 of the base portion 51 is flat. This upper surface 511 forms the bottom surface of the accommodation portion 53.

[0029] Furthermore, frame portion 52 constitutes the side surface of the inner surface of storage portion 53. Frame portion 52 is a frame-shaped member. Frame portion 52 is disposed on upper surface 511 of base portion 51. Inner surface 521 of frame portion 52 constitutes the side surface of storage portion 53.

[0030] 4, the inner shape of the frame portion 52 in this embodiment is rectangular in plan view. The inner shape of the frame portion 52 is configured to be slightly larger than the first metal plate 20 in plan view. Furthermore, the inner shape of the frame portion 52 is configured to have approximately the same dimensions as the outer shape of the second metal plate 30 in plan view. In other words, the inner shape of the frame portion 52 is configured to be sized so that the second metal plate 30 fits inside the frame portion 52.

[0031] As will be described in detail later, in the arrangement step, the first metal plate 20 is accommodated in the accommodation portion 53, and the opening of the accommodation portion 53 is closed by the second metal plate 30. Then, in the subsequent welding step, air is sucked from the internal space 11 formed between the first metal plate 20 and the second metal plate 30 in the arrangement step. For this reason, as shown in FIGS. 5A and 5B , the positioning jig 50 is provided with at least one first communication portion 54. When the first metal plate 20 and the second metal plate 30 are arranged in the positioning jig 50, the first communication portion 54 communicates the internal space 11 formed therebetween with the outside.

[0032] Specifically, the first communication portion 54 has a connecting pipe that penetrates the base portion 51 from the upper surface 511 side to the opposite lower surface 512 side. The outer diameter of the connecting pipe is configured to be approximately the same as the diameter of the through hole 21 of the first metal plate 20 described above. The end of the connecting pipe on the upper surface 511 side of the base portion 51 protrudes from the upper surface 511 of the base portion 51. The end of the connecting pipe on the lower surface 512 side of the base portion 51 is connected to the vacuum pump 60.

[0033] 3, in this embodiment, two first communicating portions 54 are provided in the positioning jig 50 (more specifically, in the base portion 51). The two first communicating portions 54 are provided at positions corresponding to the two through holes 21 of the first metal plate 20 when the first metal plate 20 is accommodated in the accommodation portion 53. More specifically, the state in which the first metal plate 20 is accommodated in the accommodation portion 53 refers to a state in which the first metal plate 20 is accommodated in the accommodation portion 53 with a gap between the end face of the first metal plate 20 and the side surface of the accommodation portion 53 around the entire periphery.

[0034] As will be described in detail later, in the welding step, air is also sucked from the closed space 56 formed by closing the opening of the accommodation portion 53 in the placement step. For this reason, as shown in Fig. 7, the positioning jig 50 is also formed with at least one second communication portion 55. The second communication portion 55 connects the closed space 56 to the outside when the opening of the accommodation portion 53 is closed.

[0035] Specifically, the second communication portion 55 has a connecting pipe that passes through the frame portion 52 from the inner surface 521 side to the opposite outer surface 522 side. The end of the connecting pipe on the outer surface 522 side of the frame portion 52 is connected to the vacuum pump 60. As shown in FIG. 3, in this embodiment, one second communication portion 55 is provided in the positioning jig 50 (more specifically, in the frame portion 52).

[0036] The vacuum pump 60 is a pump that can reduce the pressure in a target space by sucking air from the target space.

[0037] [2-2. Placement process] Next, a description will be given of the arrangement step in the manufacturing method of the laminate 1. The arrangement step is a step of arranging the first metal plate 20 and the second metal plate 30 in the pressure reducing device 4.

[0038] 5A , first, the first metal plate 20 is accommodated in the accommodation portion 53. Specifically, the first metal plate 20 is accommodated in the accommodation portion 53 so that the connecting pipe constituting the first communication portion 54 is inserted into the through hole 21 of the first metal plate 20. As a result, the surface of the first metal plate 20 facing the bottom surface of the accommodation portion 53 abuts against the bottom surface, and the end surface is spaced apart from the side surface of the accommodation portion 53 along the entire periphery.

[0039] Next, the second metal plate 30 is placed on the first metal plate 20 inside the accommodation portion 53, and the opening of the accommodation portion 53 is closed with the second metal plate 30. As described above, the second metal plate 30 of this embodiment has a curved outer periphery 33. Therefore, in this embodiment, the opening of the accommodation portion 53 is closed by fitting the second metal plate 30 inside the accommodation portion 53 with the outer periphery 33 curved away from the first metal plate 20. As a result, the surface of the second metal plate 30 facing the first metal plate 20 abuts against the first metal plate 20, and the outer periphery 33 abuts against the inner surface of the accommodation portion 53 along the entire periphery.

[0040] As described above, the second metal plate 30 is superimposed on the first metal plate 20 inside the housing portion 53, and the opening of the housing portion 53 is closed by the second metal plate 30, thereby forming an internal space 11 between the first metal plate 20 and the second metal plate 30, as shown in FIG. 5B . Furthermore, a closed space 56 is also formed. The closed space 56 is a space defined by the end face of the first metal plate 20, the second metal plate 30, and the inner surface of the housing portion 53. In this embodiment, the end face of the entire periphery of the first metal plate 20 is spaced from the side surface of the housing portion 53. Therefore, the closed space 56 is formed continuously so as to surround the outer periphery of the first metal plate 20.

[0041] [2-3. Welding process] Next, we will explain the welding step that is performed after the arranging step in the manufacturing method of the laminate 1. The welding step is a step of welding the contact portions 32 of the first metal plate 20 and the second metal plate 30 while reducing the pressure in the internal space 11 and the closed space 56 formed in the arranging step.

[0042] 6 and 7, in the welding process, the vacuum pump 60 is driven to suction air through the first communication part 54 and the second communication part 55, thereby reducing the pressure in the internal space 11 and the closed space 56. As the internal space 11 and the closed space 56 are reduced in pressure, the second metal plate 30 is pressed against the first metal plate 20 by atmospheric pressure.

[0043] Then, while air is being sucked from the internal space 11 and the closed space 56, the laser L is irradiated from the second metal plate 30 side to the contact portion 32 between the first metal plate 20 and the second metal plate 30 to weld the contact portion 32. As a result, the first metal plate 20 and the second metal plate 30 are joined together to obtain the laminate 1.

[0044] [3.Effects] According to the embodiment described above in detail, the following effects can be obtained. (3a) In the welding step, the internal space 11 and the closed space 56 formed in the arranging step are depressurized, and the contact portion 32 between the first metal plate 20 and the second metal plate 30 is welded.

[0045] With this configuration, the internal space 11 and the closed space 56 are depressurized, and the second metal plate 30 is pressed toward the first metal plate 20 by atmospheric pressure. Here, for example, if the first metal plate 20 or the second metal plate 30 is undulated, a partial gap may be formed between the first metal plate 20 and the second metal plate 30 at the outermost abutment portion 32 of the first metal plate 20 and the second metal plate 30. Even if such a gap is formed, the internal space 11 and the closed space 56, which correspond to both spaces sandwiching the outermost abutment portion 32, are both depressurized, and the second metal plate 30 is pressed toward the first metal plate 20 by atmospheric pressure. In other words, regardless of whether or not there is a gap at the outermost abutment portion 32, the adhesion force at the abutment portion 32 between the first metal plate 10 and the second metal plate 30 can be increased. Therefore, the abutment portion 32 can be well welded.

[0046] (3b) In the welding step, air is sucked through the first communicating portion 54 and the second communicating portion 55, thereby reducing the pressure in the internal space 11 and the closed space 56 formed in the arranging step.

[0047] With this configuration, even at the outermost contact portion 32, air is sucked to both sides of the contact portion 32, rather than to one side. Therefore, compared to a configuration in which air is sucked through only one of the first communicating portion 54 and the second communicating portion 55, the metal melted by the irradiation of the laser L during the welding process is more likely to spread over a wider area at the outermost contact portion 32. This makes it possible to widen the joining area between the first metal plate 20 and the second metal plate 30. In other words, it is possible to increase the joining strength between the first metal plate 20 and the second metal plate 30.

[0048] Furthermore, even at the outermost contact portion 32, air is sucked to both sides of the contact portion 32, thereby reducing the occurrence of blowholes at this contact portion 32. This also contributes to increasing the bonding strength between the first metal plate 20 and the second metal plate 30.

[0049] (3c) The second metal plate 30 is formed so that the outer periphery 33 is curved. In the placement process, the second metal plate 30 is fitted inside the accommodating portion 53. The outer periphery 33 of the second metal plate 30 abuts against the inner surface of the accommodating portion 53, thereby closing the opening of the accommodating portion 53.

[0050] With this configuration, since the outer peripheral portion 33 of the second metal plate 30 is curved, the elastic force of the outer peripheral portion 33 causes the outer peripheral portion 33 to abut more firmly against the inner surface of the accommodation portion 53. This improves the airtightness of the internal space 11 and the closed space 56. Since the internal space 11 and the closed space 56 are more easily depressurized, the adhesion force at the abutting portion 32 between the first metal plate 10 and the second metal plate 30 can be further improved.

[0051] (3d) In the placement process, the second metal plate 30 is fitted into the inside of the accommodating section 53 with the outer peripheral portion 33 curved toward the opposite side to the first metal plate 20 side within the accommodating section 53, and the outer peripheral portion 33 of the second metal plate 30 is abutted against the inner surface of the accommodating section 53.

[0052] With this configuration, when the internal space 11 and the closed space 56 are depressurized in the subsequent welding process, atmospheric pressure acts in a direction that opens the curve of the outer circumferential portion 33 of the second metal plate 30. As a result, the outer circumferential portion 33 of the second metal plate 30 abuts more strongly against the inner surface of the accommodation portion 53. This further increases the adhesion force at the abutting portion 32 between the first metal plate 20 and the second metal plate 30.

[0053] (3e) In this embodiment, the first metal plate 20 is flat. The second metal plate 30 is a plate-like member having a groove 31 formed therein. In the arrangement process, the first metal plate 20 is accommodated in the accommodation portion 53. Then, in the welding process, a laser L is irradiated from the side of the second metal plate 30 that closes the opening of the accommodation portion 53, and the first metal plate 20 and the second metal plate 30 are welded together.

[0054] Laser welding may result in uneven irradiation marks (so-called beads) on the surface irradiated with the laser. However, with the above-described configuration, in the welding process, the laser L is irradiated from the second metal plate 30 side, not the first metal plate 20 side. In other words, the occurrence of irradiation marks on the first metal plate 20 can be suppressed. Therefore, for example, when the laminate 1 is used for cooling a battery or the like, irradiation marks can be made less likely to occur on the first metal plate 20 that comes into contact with the object to be cooled. This makes it easier to bring the first metal plate 20 into close contact with the object to be cooled. In other words, the cooling efficiency of the laminate 1 can be improved.

[0055] (3f) The pressure reducing device 4 includes two vacuum pumps 60 connected to the internal space 11 and one vacuum pump 60 connected to the closed space 56. In the welding process, these separate vacuum pumps 60 are used to suck air from the internal space 11 and the closed space 56, respectively.

[0056] With this configuration, the vacuum pump 60 that sucks air directly from the internal space 11 and the vacuum pump 60 that sucks air directly from the closed space 56 are different from each other, making it easier to adjust the degree of vacuum in each of the internal space 11 and the closed space 56.

[0057] (3g) The communicating pipe constituting the first communicating portion 54 has an end portion on the upper surface 511 side of the base portion 51 protruding from the upper surface 511 of the base portion 51. In the placement process, the first metal plate 20 is accommodated in the accommodating portion 53 so that this connecting pipe is inserted into the through hole 21 of the first metal plate 20.

[0058] According to this configuration, the first metal plate 20 can be easily positioned in the arrangement step. Also, the position of the first metal plate 20 in the accommodation portion 53 can be made less likely to shift.

[0059] Additionally, in this embodiment, the outer diameter of the communicating pipe that constitutes the first communicating portion 54 is configured to be approximately the same as the diameter of the through hole 21 of the first metal plate 20. Therefore, when air is sucked through the first communicating portion 54 in the welding process, the pressure in the internal space 11 can be reduced more efficiently.

[0060] 4. Other Embodiments Although the embodiments of the present disclosure have been described above, it goes without saying that the present disclosure is not limited to the above-described embodiments and can take on various forms.

[0061] (4a) In the above embodiment, in the welding process, the internal space 11 and the closed space 56 are depressurized by sucking air through both the first communication portion 54 and the second communication portion 55. However, it is not necessary to suck air through both the first communication portion 54 and the second communication portion 55, and the internal space 11 and the closed space 56 may be depressurized by sucking air through only one of them. For example, the internal space 11 and the closed space 56 may be depressurized by sucking air through only the first communication portion 54.

[0062] (4b) In the above embodiment, the outer periphery 33 of the second metal plate 30 is curved toward the side opposite to the first metal plate 20. However, the shape of the outer periphery of the second metal plate is not particularly limited.

[0063] For example, as in the second metal plate 30A shown in FIG. 8, the outer periphery 33A may be curved toward the first metal plate 20. In this case, in the placement step, the second metal plate 30A is brought into contact with the inner surface of the accommodation portion 53A with the outer periphery 33A curved toward the first metal plate 20, thereby closing the opening of the accommodation portion 53A. Note that in the example shown in FIG. 8, the shape of the base portion 51A constituting the accommodation portion 53A is slightly different from the base portion 51 of the above embodiment so that the second metal plate 30A abuts against the first metal plate 20 inside the accommodation portion 53A when the second metal plate 30A is fitted inside the accommodation portion 53A. Specifically, a groove is formed in the base portion 51A at a position facing the outer periphery 33A of the second metal plate 30A.

[0064] Furthermore, for example, the outer periphery 33B does not have to be curved, as in the second metal plate 30B shown in Fig. 9. Even when the outer periphery 33B of the second metal plate 30B is not curved, by configuring the inner shape of the frame portion 52 and the outer shape of the second metal plate 30B in a plan view to have substantially the same dimensions, it is possible to abut the outer periphery 33B of the second metal plate 30B against the inner surface of the accommodation portion 53 to close the accommodation portion 53 in the arrangement step.

[0065] (4c) In the above embodiment, in the placement step, the first metal plate 20 is accommodated in the accommodation portion 53, and the opening of the accommodation portion 53 is closed by the second metal plate 30. The first metal plate 20 is flat. The second metal plate 30 is a plate-like member in which the groove portion 31 is formed.

[0066] However, when the internal space is formed by the flat metal plate and the metal plate with the groove formed therein as in the above embodiment, it is not necessary that the flat metal plate be housed in the housing portion and that the metal plate with the groove formed therein close the housing portion. For example, the metal plate housed in the housing portion and the metal plate closing the housing portion may be reversed.

[0067] (4d) In the above embodiment, the first metal plate 20 and the second metal plate 30 are both rectangular in plan view. As described in (4c) above, the first metal plate 20 is flat. The second metal plate 30 has a groove 31 formed therein.

[0068] However, the shapes of the first metal plate and the second metal plate are not particularly limited. For example, the first metal plate and the second metal plate may be square, polygonal other than rectangular, circular, etc. in plan view. Furthermore, for example, grooves may also be formed in the first metal plate. The grooves of the first metal plate and the second metal plate may form an internal space.

[0069] (4e) In the above embodiment, the inner shape of the frame 52 that constitutes the storage section 53 is rectangular in plan view. However, the inner shape of the frame, i.e., the inner shape of the member that forms the opening of the storage section, is not limited to a rectangular shape and may be changed as appropriate to match the outer shape of the metal plate that closes the opening of the storage section.

[0070] (4f) In the above embodiment, the storage section 53 is composed of two members: the base section 51 and the frame section 52. However, the number of members constituting the storage section is not particularly limited, and may be only one, or may be three or more.

[0071] (4g) In the above embodiment, the first communication portion 54 has a communication pipe. The end of the communication pipe on the upper surface 511 side of the base portion 51 protrudes from the upper surface 511 of the base portion 51. However, when the communication pipe constitutes the first communication portion as in the above embodiment, the communication pipe does not necessarily have to be arranged so that its end protrudes from the inner surface of the storage portion. For example, the communication pipe may be arranged so that its end is at the same height as the inner surface of the storage portion.

[0072] (4h) In the above embodiment, the decompression device 4 includes three vacuum pumps 60. However, the number of vacuum pumps included in the decompression device is not particularly limited.

[0073] For example, the decompression device may be provided with two vacuum pumps, one connected to the internal space 11 and the other connected to the closed space 56, thereby realizing a configuration in which air is sucked directly and separately from the internal space 11 and the closed space 56, as in the above embodiment. Alternatively, for example, the decompression device may be provided with a single vacuum pump that sucks air directly from both the internal space 11 and the closed space 56.

[0074] In these cases, for example, air may be sucked from the internal space 11 through both of the two through holes 21 that function as the inlet end 12 and the outlet end 13 in the finished laminate 1, or air may be sucked from the internal space 11 through only one of the through holes 21 when the other through hole 21 is blocked.

[0075] (4i) In the above embodiment, the laser beam L is irradiated onto the contact portion 32 between the first metal plate 20 and the second metal plate 30 while air is being sucked out of the internal space 11 and the closed space 56. As a result, the molten metal may be drawn in the direction of the air being sucked in, potentially leaving a dented irradiation mark on the surface irradiated with the laser beam L. Therefore, when a laser is used as a means for welding the contact portion between the first metal plate and the second metal plate as in the above embodiment, a welding filler (filler material) such as a welding wire or welding rod may be used when irradiating the laser beam. This configuration can prevent large dented irradiation marks from being left on the surface irradiated with the laser beam.

[0076] (4j) In the above embodiment, the laminate 1 is a cooler, but the use of the laminate is not particularly limited. For example, the laminate may be used for heating purposes in addition to or instead of cooling purposes. Also, for example, the laminate may be used as a container that stores an object in its internal space, such as a fuel tank. The shape and size of the internal space may be changed as appropriate depending on the use of the laminate.

[0077] (4k) The functions of one component in the above embodiments may be distributed among multiple components, or the functions of multiple components may be integrated into one component. Also, part of the configuration of the above embodiments may be omitted. Furthermore, at least part of the configuration of the above embodiments may be added to or substituted for the configuration of another of the above embodiments. [Explanation of symbols]

[0078] 1...laminated body, 11...internal space, 20...first metal plate, 30...second metal plate, 31...groove portion, 32...contact portion, 33...periphery, 4...pressure reducing device, 50...positioning jig, 51...base portion, 52...frame portion, 53...accommodation portion, 54...first communicating portion, 55...second communicating portion, 56...closed space, 60...vacuum pump, L...laser.

Claims

1. A method for manufacturing a laminate in which an internal space is formed between a first metal plate and a second metal plate, accommodating the first metal plate in a recessed accommodation portion, and closing an opening of the accommodation portion with the second metal plate while overlapping the second metal plate on the first metal plate; reducing the pressure in the internal space formed by overlapping the first metal plate and the second metal plate and in the closed space formed by closing the opening of the accommodating portion, and welding the abutting portion between the first metal plate and the second metal plate; Equipped with the second metal plate has a curved outer periphery, The method for manufacturing a laminate, wherein the outer peripheral portion abuts against the inner surface of the storage portion, thereby closing the opening of the storage portion.

2. A method for producing the laminate according to claim 1, A method for manufacturing a laminate, wherein the outer periphery abuts against the inner surface of the accommodation portion in a direction curved away from the first metal plate side within the accommodation portion.

3. A method for producing the laminate according to claim 1 or claim 2, A method for manufacturing a laminate, in which air is sucked in through both a first communication portion that connects the internal space to the outside and a second communication portion that connects the closed space to the outside, thereby reducing the pressure in the internal space and the closed space.

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