Method for manufacturing terminal component for battery

Abstract

To suppress occurrence of burrs in an outer edge portion of an individual clad piece.SOLUTION: A method for manufacturing a terminal component includes: a step (1) of disposing an individual clad piece 31 so that a high-ductility conductor layer 31A is in contact with a bottom surface 52 of a vertical hole part 51 opened upward in a lower mold 50 when disposing, in the lower mold 50, the individual clad piece 31 formed by laminating and joining the high-ductility conductor layer 31A and a low-ductility conductor layer 31B in a thickness direction; and a step (2) of forming a projection part 32C in a projection part forming recess part 56 by plastically deforming the individual clad piece 31 toward the projection part forming recess part 56 while restraining plastic deformation of side surfaces of the individual clad piece 31 by means of an inner peripheral wall 53 of the vertical hole part 51 of the lower mold 50, by the projection part forming recess part 56 opened downward and extending upward in order to form the projection part 32C serving as an axial part on the center of the individual clad piece 31 in an upper mold 55A when entering the upper mold 55A into the vertical hole part 51 of the lower mold 50 and pressurizing an upper surface of the low-ductility conductor layer 31B of the individual clad piece 31.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a battery terminal component, and more particularly, to a method for manufacturing a battery terminal component used in a secondary battery module such as a lithium-ion secondary battery.

Background Art

[0002] Patent Document 1 describes a lithium-ion secondary battery (LIB) including a positive electrode made of an aluminum foil, a negative electrode made of a copper foil, a separator between the positive electrode and the negative electrode, and an electrolytic solution, wherein the positive electrode, the negative electrode, the separator, and the electrolytic solution are housed in a case. In the LIB, the positive electrode is connected to a positive electrode current collector in the case, and the positive electrode current collector is electrically connected to a positive electrode terminal that penetrates the case. Further, the positive electrode terminal is connected to a bus bar outside the case. On the other hand, the negative electrode is connected to a negative electrode current collector in the case, and the negative electrode current collector is electrically connected to a negative electrode terminal that penetrates the case. Further, the negative electrode terminal is connected to a bus bar outside the case.

[0003] In recent years, bus bars (Al bus bars) made of aluminum or aluminum alloys have been used for weight reduction. Therefore, in the LIB, positive electrode terminals made of aluminum or aluminum alloys are used for connecting a positive electrode current collector made of aluminum or an aluminum alloy and an Al bus bar. On the other hand, copper or copper alloys are used for the negative electrode current collector. Therefore, Patent Document 1 describes that, in the negative electrode terminal, the portion in contact with the negative electrode current collector is made of copper or a copper alloy, and the portion in contact with the Al bus bar is made of aluminum or an aluminum alloy.

[0004] Specifically, the negative electrode terminal of Patent Document 1 has a shaft portion and a flange portion that radially spreads in the radial direction from the shaft portion, and is composed of a clad material in which a highly ductile conductor layer made of aluminum or an aluminum alloy and a low ductile conductor layer made of copper or a copper alloy are joined. In Patent Document 1, the outer shape of the terminal component is formed by press-molding a two-layer clad piece composed of two types of metals. Specifically, the clad material is placed in a lower mold provided with a concave portion corresponding to the shaft portion so that the low ductile conductor layer faces downward, and is forged and pressed by an upper mold from the side of the highly ductile conductor layer. As a result, a shaft portion in which the central portion on the side of the low ductile conductor layer protrudes is formed, and a battery terminal is formed so that the remaining portion of the clad material becomes a flange portion.

[0005] Patent Document 2 describes a terminal component for a secondary battery having a plate-shaped head having a bottom surface and an upper surface opposite to the bottom surface, and a shaft portion extending from the bottom surface. The terminal component includes copper (low ductile conductor) and aluminum (highly ductile conductor). The bottom surface of the head is made of copper, and the upper surface of the head is made of aluminum. Patent Document 2 describes that in order to suppress burrs generated by the highly ductile conductor layer made of aluminum on the upper surface side of the head, which is more easily plastically deformed than copper, from flowing quickly and entering the gap between the low ductile conductor layer made of copper on the bottom surface side of the head and the mold, a chamfered portion continuous in the circumferential direction is provided on the outer peripheral portion of the bottom surface of the head.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] By the way, when forging and pressing a clad piece having a two-layer structure in which a highly ductile conductor layer made of aluminum or an aluminum alloy and a low-ductile conductor layer made of copper or a copper alloy are joined, the low-ductile conductor layer is arranged in a lower die provided with a recess corresponding to the shaft portion so as to face downward, and when forging and pressing with an upper die from the side of the highly ductile conductor layer, the highly ductile conductor layer may enter between the lower die and the upper die at the outer edge portion of the clad piece, resulting in burrs. When such burrs occur, it takes time to remove the burrs from the formed clad piece. Further, after removing the clad piece from the die, if the burrs separate from the formed clad piece and remain on the lower die or the upper die, it will prevent the next clad piece from being formed. For this reason, it takes time to clean the lower die or the upper die where the released burrs may remain.

[0008] An object of the present invention is to suppress the generation of burrs between a lower die and an upper die at the outer edge portion of a clad piece when manufacturing a terminal component of a battery, using a clad plate in which a highly ductile conductor layer and a low-ductile conductor layer are laminated and joined in the thickness direction, and having a shaft portion extending in the thickness direction of the clad plate and a flange portion extending in a direction orthogonal to the thickness direction of the clad plate from the shaft portion.

Means for Solving the Problems

[0009] To solve the above problems, a first aspect of the present invention is a manufacturing method for manufacturing a battery terminal component having a shaft portion extending in the thickness direction of a clad plate and a flange portion extending in a direction orthogonal to the thickness direction from the shaft portion, using a clad plate in which a highly ductile conductor layer and a low-ductile conductor layer having lower ductility than the highly ductile conductor layer are laminated and joined in the thickness direction, comprising: When arranging a clad piece formed by punching the clad plate in the thickness direction in a lower die, a step (1) of arranging the clad piece so that the highly ductile conductor layer contacts the bottom surface of a vertical hole portion opening upward in the lower die; When the upper mold enters the vertical hole portion of the lower mold and presses the upper surface of the low-ductility conductor layer of the clad piece, in the upper mold, a concave portion for forming a convex portion serving as the shaft portion is formed at the center of the clad piece in the orthogonal direction, opening downward and extending upward. By this concave portion for forming a convex portion, while restraining plastic deformation of the side surface of the clad piece by the inner peripheral wall of the vertical hole portion of the lower mold, the clad piece is plastically deformed toward the concave portion for forming a convex portion, and the convex portion is formed inside the concave portion for forming a convex portion (step (2)).

[0010] It is preferable that an inclined surface inclined upward toward the center in the orthogonal direction is provided at the inner peripheral edge of the inner peripheral wall of the concave portion for forming a convex portion of the upper mold.

[0011] It is preferable that the gradient of the inclined surface of the inner peripheral edge of the upper mold with respect to the bottom surface of the vertical hole portion of the lower mold increases toward the center in the orthogonal direction.

[0012] The upper mold has a plurality of flat surfaces or curved surfaces that are continuous from the outer peripheral portion at the lower end toward the center in the orthogonal direction, and it is preferable that the gradient of the plurality of flat surfaces or curved surfaces with respect to the bottom surface of the vertical hole portion of the lower mold increases toward the center in the orthogonal direction.

[0013] The upper mold has a plurality of conical surfaces that are continuously inclined upward from the outer peripheral portion at the lower end toward the center in the orthogonal direction, and it is preferable that the plurality of conical surfaces have a smaller taper angle toward the upper part.

[0014] In step (2), when the thickness of the high-ductility conductor layer is TH and the thickness of the low-ductility conductor layer is TL at the outer peripheral edge of the clad piece, it is preferable to extend the clad piece into the concave portion for forming a convex portion of the upper mold until TL / (TH + TL) ≤ 0.2 is satisfied.

[0015] After step (2), it may have a step (3) of extending the convex portion to form the shaft portion.

[0016] After the step (3), a step (4) of forming a bottomed hole at one end side of the shaft portion may be included.

[0017] After the step (4), a step (5) of forming the flange portion extending radially from the shaft portion by pressing the other end side of the shaft portion opposite to the one end side may be included.

[0018] After the step (5), a step (6) of trimming the outermost peripheral portion of the flange portion may be included.

[0019] It is preferable to perform the steps (1) to (6) by transfer press forming.

Advantages of the Invention

[0020] According to the present invention, in step (1), the highly ductile conductor layer is restrained by the lower die having a vertical hole portion opening upward, and in step (2), by pressing from the side of the low-ductile conductor layer with the upper die having a concave portion for forming a convex portion opening downward and extending upward, the axial component of the pressing force acting on the central portion rather than the outer edge portion of the clad piece becomes smaller, and the low-ductile conductor layer easily plastically flows toward the central portion of the clad piece. For this reason, intrusion of the low-ductile conductor layer between the lower die and the upper die at the outer edge portion of the clad piece is suppressed, and generation of burrs of the low-ductile conductor layer between the lower die and the upper die is suppressed. Further, since the highly ductile conductor layer is pressed from the side of the low-ductile conductor layer while being restrained by the lower die, intrusion of the highly ductile conductor layer between the lower die and the upper die at the outer edge portion of the clad piece is suppressed, and generation of burrs of the highly ductile conductor layer between the lower die and the upper die is suppressed.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0022] Hereinafter, embodiments of the battery terminal component according to the present invention will be described with reference to the drawings by giving configuration examples.

[0023] The terminal component for a battery according to the present invention is formed, for example, in a rivet shape. FIG. 1 is a cross-sectional view of a terminal component 1 according to an embodiment of the terminal component for a battery according to the present invention. As shown in FIG. 1, the terminal component 1 is formed in a rivet shape. The terminal component 1 has a shaft portion 10 extending in one direction (Z1 direction), and a flange portion 20 extending in a direction orthogonal to the shaft portion 10 (X1, X2 directions and Y1, Y2 directions orthogonal to X1, X2, Z1, Z2) from one end of the shaft portion 10. A bottomed hole portion 11 is provided at one end of the shaft portion 10. The outer peripheral portion of the shaft portion 10 is formed of a low-ductility conductor. Further, in the flange portion 20, the surface 21 on the side opposite to the shaft portion 10 (Z2 side) is formed of a high-ductility conductor, and the surface 22 on the side of the shaft portion 10 (Z1 side) is formed of a low-ductility conductor.

[0024] The high-ductility conductor preferably has a standard electrode potential comparable to that of the bus bar of a lithium-ion battery. As the high-ductility conductor, the same material as that of the bus bar can be used. For example, aluminum or an aluminum alloy can be used. Examples of aluminum include A1050 and A1100 of the A1000 series defined in JIS-H4000:2022. Examples of aluminum alloys include Al-Mn-based alloys of the A3000 series and Al-Mg-based alloys of the A5000 series defined by the same JIS regulations.

[0025] The low-ductility conductor is a conductor having lower ductility than the high-ductility conductor. Here, the "ductility" can be evaluated, for example, by the plastic elongation at the maximum test force defined in JIS-Z2241:2011. The standard electrode potential of the low-ductility conductor is preferably comparable to that of the negative electrode current collector of a lithium-ion battery. As the low-ductility conductor, the same material as that of the negative electrode current collector of a lithium-ion battery can be used. For example, copper or a copper alloy can be used. Examples of copper include C1020 and C1100 defined in JIS-H3100:2018. Examples of copper alloys include C1441, C1921, C1940, and C7250 defined by the same JIS regulations.

[0026] FIG. 2 is a cross-sectional view showing a fixing portion of the terminal component 1 between the case 201 of the battery 200 and the negative electrode current collector 202. As shown in FIG. 2, the shaft portion 10 of the terminal component 1 penetrates the case 201 of the battery 200 and the negative electrode current collector 202 inside the case 201 from the outside (Z2 side) to the inside (Z1 side) of the case 201. Then, inside the case 201 (Z1 side), the terminal component 1 is caulked by bending and expanding the end portion of the bottomed hole portion 11 of the shaft portion 10 in the direction orthogonal to the axial direction (Z1 direction) (X1, X2 directions and Y1, Y2 directions). In this state, the terminal component 1 is electrically connected to the negative electrode current collector 202 and fixes the negative electrode current collector 202 to the case 201. Further, a packing 207 is provided between the flange portion 20 of the terminal component 1 and the case 201, and a packing 208 is provided between the case 201 and the negative electrode current collector 202. The packings 207 and 208 suppress the leakage of the electrolyte inside the battery 200.

[0027] As shown in FIG. 2, in the state where the terminal component 1 is caulked, the surface 21 on the side opposite to the shaft portion 10 (Z2 side) of the flange portion 20 of the terminal component 1 is in contact with the bus bar 209 and is electrically connected. The battery 200 is connected to other batteries (not shown) and external electronic devices via the bus bar 209.

[0028] Hereinafter, a method for manufacturing a battery terminal component according to an embodiment of the present invention will be described with reference to the drawings as appropriate, taking the manufacturing method of the terminal component 1 described above as an example.

[0029] The manufacturing method of the terminal component 1 according to the embodiment of the manufacturing method of the battery terminal component according to the present invention includes the following steps (A) to (G). (A) Step of forming clad pieces from a clad plate (B) Step of forming a convex portion to be a shaft portion from the clad pieces (C) Step of forming a shaft portion by stretching the convex portion (D) Step of forming an intermediate bottomed hole portion on one end side of the shaft portion (E) Step of forming a bottomed hole portion on one end side of the shaft portion (F) Step of forming a flange portion by pressing the other end side of the shaft portion (G) Step of trimming the outermost peripheral part of the flange portion

[0030] The above steps (A) to (G) are preferably performed by transfer press molding. Hereinafter, each step will be described.

[0031] (A) Step of forming clad pieces from a clad plate FIG. 3 is a cross-sectional view for explaining step (A) of forming clad pieces 31 (see FIG. 4) from a clad plate 30. As shown in FIG. 3, the clad plate 30 is formed by laminating and joining a high-ductility conductor layer 30A and a low-ductility conductor layer 30B having lower ductility than the high-ductility conductor layer 30A in the thickness direction (Z1, Z2 directions). The high-ductility conductor layer 30A is a layer made of a conductor having a standard electrode potential comparable to that of the bus bar of the battery. For the high-ductility conductor layer 30A, for example, aluminum or an aluminum alloy can be used. The low-ductility conductor layer 30B is a layer made of a conductor having lower ductility than the high-ductility conductor and having a standard electrode potential comparable to that of the negative electrode current collector of the battery. For the low-ductility conductor layer 30B, for example, copper or a copper alloy can be used.

[0032] To form clad pieces 31 (see FIG. 4) from the clad plate 30, as shown in FIG. 3, the clad plate 30 is placed on the die 40 having a hole 41 of a predetermined shape on the upper side (Z1 side) using a press working machine or the like, and a punch 42 having a predetermined shape is lowered from above (Z1 side) to perform punching. The predetermined shape here is intended to be a shape corresponding to the shape of the clad piece 31. Thereby, the clad pieces 31 can be produced from the clad plate 30. At this time, as shown in FIG. 3, a guide 43 for guiding the punch 42 may be provided. In FIG. 3, a configuration is shown in which punching is performed with the clad plate 30 arranged such that the high-ductility conductor layer 30A contacts the die 40, but a configuration in which punching is performed with the clad plate 30 arranged such that the low-ductility conductor layer 30B contacts the die 40 may also be used.

[0033] (B) Step of forming a convex portion that becomes a shaft portion from the clad piece Figs. 4 and 5 are cross-sectional views for explaining the process (B) of forming the convex portion 32C (see Fig. 7) which becomes the shaft portion 33C (see Fig. 10) from the clad piece 31. Fig. 4 shows the process of arranging the clad piece 31 in the die 50 in the process (B). Fig. 5 shows the process of forming the convex portion 32C which becomes the shaft portion 33C from the clad piece 31 in the process (B).

[0034] First, as shown in Fig. 4, when arranging the clad piece 31 formed by punching the clad plate 30 in the thickness direction (Z2 direction) in the die 50 serving as the lower die, in the die 50, the clad piece 31 is arranged so that the highly ductile conductor layer 31A contacts the bottom surface 52 of the vertical hole portion 51 that opens upward (Z1 side). At this time, the inner peripheral wall of the vertical hole portion 51 of the die 50 is arranged slightly outside the outer peripheral end surface (side surface in the direction orthogonal to the Z1 and Z2 directions) of the clad piece 31. For this reason, since the inner peripheral wall 53 of the vertical hole portion 51 of the die 50 and the outer peripheral end surface of the clad piece 31 are close to each other and in a clearance fit state, the outer peripheral end surface (side surface in the direction orthogonal to the Z1 and Z2 directions) and the lower surface (surface on the Z2 side) of the highly ductile conductor layer 31A are constrained by the die 50. Note that the die 50 is an example of the lower die in the present invention.

[0035] Next, as shown in Fig. 5, when the punch 55A serving as the upper die enters the vertical hole portion 51 of the die 50 and presses the upper surface (surface on the Z1 side) of the low ductility conductor layer 31B of the clad piece 31, in the punch 55A, a convex portion forming concave portion 56 that opens downward (Z2 side) and extends upward (Z1 side) for forming the convex portion 32C (see Fig. 7) that becomes the shaft portion 10 at the center in the direction orthogonal to the thickness direction of the clad piece 31 (X1, X2 directions and Y1, Y2 directions) presses the low ductility conductor layer 31B of the clad piece 31 from the outer peripheral portion of the upper surface. Thereby, while restraining the plastic deformation of the outer peripheral side surface (surface in the direction orthogonal to the Z1 and Z2 directions) of the clad piece 31 by the inner peripheral wall 53 of the vertical hole portion 51 of the die 50, the clad piece 31 is plastically deformed toward the convex portion forming concave portion 56, and the convex portion 32C can be formed inside the convex portion forming concave portion 56. Note that the punch 55A is an example of the upper die in the present invention.

[0036] The punch 55A has, at the center of the direction orthogonal to its axial direction (Z1, Z2 directions), a concave portion 56 for forming a convex portion that opens downward (Z2 side) and extends upward (Z1 side). Note that the axial direction of the punch 55A corresponds to the thickness direction of the clad plate 30 and the individual clad pieces 31. Also, the direction orthogonal to the axial direction of the punch 55A corresponds to the direction orthogonal to the thickness direction of the clad plate 30 and the individual clad pieces 31. In the punch 55A, the concave portion 56 for forming a convex portion may be configured as a hole penetrating in the vertical direction (Z1, Z2 directions), or may be configured as a non-penetrating concave portion.

[0037] As described above, while restraining the plastic deformation of the outer peripheral side surface (the surface in the direction orthogonal to the Z1, Z2 directions) of the individual clad piece 31 by the inner peripheral wall 53 of the vertical hole portion 51 of the die 50, by pressing the low-ductility conductor layer 31B of the individual clad piece 31 with the punch 55A, the individual clad piece 31 can be plastically deformed toward the concave portion 56 for forming a convex portion of the punch 55A. In the thickness direction (Z1, Z2 directions) of the individual clad piece 31, the stress acting on the central portion of the individual clad piece 31 is smaller than the stress acting on the outer edge portion of the individual clad piece 31 due to the pressing of the concave portion 56 for forming a convex portion of the punch 55A. Therefore, the low-ductility conductor layer 31B easily plastically flows toward the central portion of the individual clad piece 31, and generation of burrs due to the distorted plastic flow of the low-ductility conductor layer 31B can be suppressed on the upper surface (Z1 side) of the outer edge portion of the individual clad piece 31.

[0038] As shown in FIG. 5, it is preferable that an inclined surface 57 inclined upward (Z1 side) toward the inside (the center of the individual clad piece 31) is provided on the inner peripheral edge of the concave portion 56 for forming a convex portion of the punch 55A. By providing the inclined surface 57 on the inner peripheral edge of the concave portion 56 for forming a convex portion of the punch 55A, inside the concave portion 56 for forming a convex portion, the low-ductility conductor layer 31B can be plastically flowed upward (Z1 side) along the inclined surface 57.

[0039] It is preferable that the gradient of the inclined surface 57 of the concave portion 56 for forming the convex portion of the punch 55A with respect to the bottom surface 52 of the vertical hole portion 51 of the die 50 increases toward the inside (the center of the clad individual piece 31). That is, assuming a tangent surface to the inclined surface 57, the angle formed by the outer peripheral surface of the punch 55A and the tangent surface to the inclined surface 57 is less than 90 degrees, and it is preferable that the angle gradually decreases from the outer peripheral side of the punch 55A toward the inside (the center of the clad individual piece 31). Actually, in a cross-section along the axial direction (Z1, Z2 directions) of the punch 55A (the cross-section shown in FIG. 5), the angle formed by the line indicating the outer peripheral surface of the punch 55A and the line (tangent line) indicating the tangent surface of the inclined surface 57 is less than 90 degrees, and it is preferable that the angle gradually decreases from the outer peripheral side of the punch 55A toward the inside (the center of the clad individual piece 31). When the gradient of the inclined surface 57 increases toward the inside (the center of the clad individual piece 31), the stress acting on the clad individual piece 31 due to pressing decreases as it goes from the outer edge portion to the central portion of the clad individual piece 31. For this reason, the plastic flow of the clad individual piece 31 easily heads toward the center in the X direction (the center of the clad individual piece 31), and it becomes easier to plastically flow the low-ductility conductor layer 31B toward the concave portion 56 for forming the convex portion. When pressing the clad individual piece 31 with the punch 55A, a guide 59 for guiding the punch 55A in the vertical direction (Z1, Z2 directions) may be used.

[0040] Note that the punch 55A shown in FIG. 5 has an inclined surface 57 whose gradient continuously increases toward the center of the clad individual piece 31, but a punch having another shape, for example, a punch having the shape of the punch 55B shown in FIG. 6, may be used.

[0041] FIG. 6 is a cross-sectional view showing another form of the punch 55B. As shown in FIG. 6, the punch 55B has a shape different from that of the punch 55A shown in FIG. 5. The punch 55B has a plurality of inclined surfaces 57A, 57B, 57C, 57D that are continuous from the outer peripheral portion at the lower end thereof toward the inside (the center of the clad piece 31). The inclined surfaces 57A to 57D are continuous in the order of the inclined surfaces 57A, 57B, 57C, 57D from the outer peripheral portion toward the inside (the center of the clad piece 31). It is preferable that the gradients of the inclined surfaces 57A to 57D of the concave portion 56 for forming the convex portion of the punch 55B with respect to the bottom surface 52 of the vertical hole portion 51 of the die 50 are such that the inclined surface 57A is the smallest, and the inclined surfaces 57B, 57C, and 57D increase in this order.

[0042] Note that the inclined surfaces 57A, 57B, 57C, and 57D may each be a flat surface or a curved surface. For example, the inclined surfaces 57A, 57B, 57C, and 57D may each be a conical surface. In this case, if the taper angles of the inclined surfaces 57A, 57B, 57C, and 57D are θ1, θ2, θ3, and θ4, respectively, it is preferable that θ1 > θ2 > θ3 > θ4.

[0043] FIG. 7 is a cross-sectional view showing the intermediate body 32 formed in the step (B) by the die 50 and the punch 55A shown in FIG. 5. Note that the intermediate body 32 can also be formed by the die 50 shown in FIG. 5 and the punch 55B shown in FIG. 6. As shown in FIG. 7, the intermediate body 32 has a high-ductility conductor layer 32A and a low-ductility conductor layer 32B, and a convex portion 32C is provided at the central portion on the low-ductility conductor layer 32B side. Note that the position of the convex portion 32C on the low-ductility conductor layer 32B side corresponds to the central portion of the clad piece 31 on the low-ductility conductor layer 32B side.

[0044] When the thickness of the highly ductile conductor layer 32A is TH and the thickness of the low ductile conductor layer 32B is TL at the outer peripheral edge of the intermediate body 32, it is preferable to satisfy TL / (TH + TL) ≤ 0.2, and it is more preferable to satisfy TL / (TH + TL) ≤ 0.1. That is, in step (B), it is preferable to extend the convex portion 32C into the concave portion 56 for forming the convex portion of the punch 55A until TL / (TH + TL) ≤ 0.2 is satisfied, and it is more preferable to extend the convex portion 32C into the concave portion 56 for forming the convex portion of the punch 55A until TL / (TH + TL) ≤ 0.1 is satisfied.

[0045] (C) Step of extending the convex portion to form the shaft portion FIGS. 8 and 9 are cross-sectional views for explaining step (C) of extending the convex portion 32C to form the shaft portion 33C (see FIG. 10). FIG. 8 shows a state where the intermediate body 32 is disposed in the die 60 in step (C). As shown in FIG. 8, in the vertical hole portion 61 of the die 60 that opens upward (Z1 side), the intermediate body 32 is disposed such that the highly ductile conductor layer 32A side thereof is in contact with the bottom surface 62 of the vertical hole portion 61. Further, the side surface of the intermediate body 32 in the direction orthogonal to the Z1 and Z2 directions is close to the inner peripheral wall 63 of the vertical hole portion 61 of the die 60. Thereby, the surface on the Z2 side of the highly ductile conductor layer 32A and the side surface in the direction orthogonal to the Z1 and Z2 directions are constrained by the bottom surface 62 and the inner peripheral wall 63 of the vertical hole portion 61 of the die 60.

[0046] Next, the convex portion 32C of the intermediate body 32 is extended to form the shaft portion 33C. FIG. 9 shows the step of pressing the outer peripheral portion of the low-ductility conductor layer 32B of the intermediate body 32 by the punch 65 to extend the convex portion 32C in the process (C). As shown in FIG. 9, from above (Z1 side) of the vertical hole portion 61 of the die 60, the outer peripheral portion of the low-ductility conductor layer 32B of the intermediate body 32 is pressed by the punch 65. The punch 65 has a concave portion 66 for forming a shaft portion that opens downward (Z2 side) and extends upward (Z1 side) inside thereof (at the center of the clad piece 31). Note that the concave portion 66 for forming a shaft portion may be formed of a hole that penetrates the punch 65 in the vertical direction (Z1, Z2 directions), or may be formed of a non-penetrating concave portion. By pressing the outer peripheral portion of the low-ductility conductor layer 32B of the intermediate body 32 with the punch 65, while restraining the plastic deformation of the side surfaces of the clad piece 31 in the X1 and X2 directions by the inner peripheral wall 63 of the vertical hole portion 61 of the die 60, the convex portion 32C of the intermediate body 32 is plastically deformed toward the Z1 side inside the concave portion 66 for forming a shaft portion, and the shaft portion 33C (see FIG. 10) can be formed inside the concave portion 66 for forming a shaft portion. At this time, since the stress acting on the central portion of the intermediate body 32 due to pressing becomes smaller than that on the outer edge portion, the low-ductility conductor layer 32B easily plastically flows toward the center in the direction orthogonal to the thickness direction. Therefore, the generation of burrs in the low-ductility conductor layer 32B can be suppressed.

[0047] As shown in FIG. 9, it is preferable that an inclined surface 67 inclined upward (Z1 side) toward the inside (center of the clad piece 31) is provided at the inner peripheral edge portion of the concave portion 66 for forming a shaft portion of the punch 65. When the inclined surface 67 is provided, the low-ductility conductor layer 32B can be plastically flowed more smoothly upward (Z1 side) inside the concave portion 66 for forming a shaft portion along the inclined surface 67. Note that when pressing the intermediate body 32 with the punch 65, a guide 69 for guiding the punch 65 in the vertical direction (Z1, Z2 directions) may be used.

[0048] (D) Step of forming an intermediate bottomed hole portion on one end side of the shaft portion FIG. 10 is a cross-sectional view for explaining a step (D) of forming an intermediate bottomed hole portion 34D (see FIG. 11) on one end side of a shaft portion 33C. FIG. 10 shows a state where an intermediate body 33 formed in step (C) is disposed in a die 70. As shown in FIG. 10, in the intermediate body 33 formed in the above step (C), the shaft portion 33C faces upward (Z1 side) in a vertical hole portion 71 that opens upward (Z1 side) of the die 70, and the high-ductility conductor layer 33A side is disposed in contact with the bottom surface 72 of the vertical hole portion 71. Further, the side surface of the intermediate body 33 in a direction orthogonal to the Z1 and Z2 directions is close to the inner peripheral wall 73 of the vertical hole portion 71 of the die 70. As a result, the surface on the Z2 side of the high-ductility conductor layer 33A and the side surface in a direction orthogonal to the Z1 and Z2 directions are constrained by the bottom surface 72 and the inner peripheral wall 73 of the vertical hole portion 71 of the die 70.

[0049] Next, as shown in FIG. 10, a punch 75 having a substantially flat tip portion at the tip is lowered from above (Z1 side) to below (Z2 side) the vertical hole portion 71 of the die 70, and the tip portion of the punch 75 presses the tip portion of the shaft portion 33C. As a result, an intermediate bottomed hole portion 34D (see FIG. 11) in which the shape of the tip portion of the punch 75 is transferred is formed at the tip portion of the shaft portion 33C.

[0050] (E) Step of forming a bottomed hole portion on one end side of the shaft portion FIG. 11 is a cross-sectional view for explaining a step (E) of forming a bottomed hole portion 35D (see FIG. 12) on one end side (Z1 side) of a shaft portion 34C having an intermediate bottomed hole portion 34D of an intermediate body 34. As shown in FIG. 11, in step (E), the intermediate body 34 obtained in the above step (D) is disposed in a vertical hole portion 81 that opens upward (Z1 side) of a die 80, with the intermediate bottomed hole portion 34D of the intermediate body 34 facing upward (Z1 side) and the high-ductility conductor layer 34A side in contact with the bottom surface 82 of the vertical hole portion 81 of the die 80. Further, the side surface of the intermediate body 34 in a direction orthogonal to the Z1 and Z2 directions is close to the inner peripheral wall 83 of the vertical hole portion 81 of the die 80. As a result, the surface on the Z2 side of the high-ductility conductor layer 34A and the side surface in a direction orthogonal to the Z1 and Z2 directions are constrained by the bottom surface 82 and the inner peripheral wall 83 of the vertical hole portion 81 of the die 80.

[0051] Next, as shown in FIG. 11, the punch 85 is lowered from above (Z1 side) to below (Z2 side) the vertical hole portion 81 of the die 80, the tip of the punch 85 is inserted into the intermediate bottomed hole portion 34D, and the punch 85 is further lowered to press the intermediate body 34. As a result, a bottomed hole portion 35D (see FIG. 12) having the shape of the tip of the punch 85 transferred thereto is formed.

[0052] (F) Step of forming a flange portion by pressing the other end side of the shaft portion FIG. 12 is a cross-sectional view for explaining the step (F) of forming a flange portion by pressing the other end side (Z2 side) of the shaft portion 35C of the intermediate body 35. The flange portion formed here is a flange portion prototype corresponding to the flange portion 20 shown in FIG. 1. As shown in FIG. 12, in step (F), the intermediate body 35 obtained in the above step (E) is placed on the upper surface 92 of the die 90. Specifically, the intermediate body 35 is placed on the upper surface 92 of the die 90 such that the bottomed hole portion 35D of the intermediate body 35 faces upward (Z1 side) and the high-ductility conductor layer 35A side is in contact with the upper surface 92 of the die 90.

[0053] Next, as shown in FIG. 12, the punch 95 is lowered from above (Z1 side) to below (Z2 side). At this time, the punch 95 is lowered toward the inclined surface on the Z1 side (the inclined surface on the outer peripheral side of the low-ductility conductor layer 35B) on the outer peripheral side of the shaft portion 35C of the intermediate body 35. By appropriately pressing the inclined surface on the Z1 side on the outer peripheral side of the shaft portion 35C of the intermediate body 35 with the die 90 and the punch 95, the inclined surface on the outer peripheral side is plastically deformed toward the Z2 side, and a flange portion (flange portion prototype) is formed.

[0054] (G) Step of trimming the outermost peripheral portion of the flange portion Next, for the intermediate body (not shown) in which the flange portion (flange portion prototype) is formed in step (F), if necessary, the outermost peripheral portion of the flange portion (flange portion prototype) is trimmed. As a result, the terminal component 1 having the shaft portion 10 and the flange portion 20 shown in FIG. 1 is completed. If the above trimming is not performed, the flange portion (flange portion prototype) formed in step (F) becomes the flange portion 20 shown in FIG. 1.

[0055] As described above, in the manufacturing method of the terminal component 1 according to the embodiment of the manufacturing method of the battery terminal component according to the present invention, in step (A), the clad plate 30 is punched in the thickness direction (Z1, Z2 directions) to form clad pieces 31. Then, in step (B), when the clad piece 31 formed in step (A) is placed in the lower die (die 50), in the lower die (die 50), the clad piece 31 is placed so that the highly ductile conductor layer 31A contacts the bottom surface 52 of the vertical hole portion 51 that opens upward (Z1 side). When the upper die (punch 55A) enters the vertical hole portion 51 of the lower die (die 50) and presses the upper surface (Z1 side) of the low-ductile conductor layer 31B of the clad piece 31, in the upper die (punch 55A), a convex portion 32C that becomes the shaft portion 33C is formed at the center in the direction orthogonal to the thickness direction of the clad piece 31 (X1, X2 directions and Y1, Y2 directions). The clad piece 31 is plastically deformed toward the convex portion forming recess 56 while the plastic deformation of the side surface in the X direction of the clad piece 31 is restricted by the inner peripheral wall 53 of the vertical hole portion 51 of the lower die (die 50), and the convex portion 32C is formed inside the convex portion forming recess 56.

[0056] Thereby, in step (B) of forming the convex portion 32C that becomes the shaft portion 33C from the clad piece 31, the side surface in the direction orthogonal to the thickness direction of the clad piece 31 is restricted by the inner peripheral wall 53 of the vertical hole portion 51, and the punch 55A having the convex portion forming recess 56 that opens downward (Z2 side) presses from the low-ductile conductor layer 31B side. As a result, the stress acting on the central portion of the clad piece 31 due to the pressing becomes smaller than that on the outer edge portion, and the low-ductile conductor layer 31B easily plastically flows toward the center. For this reason, the intrusion of the low-ductile conductor layer 31B between the die 50 and the punch 55A at the outer edge portion of the clad piece 31 is suppressed, and the generation of burrs of the low-ductile conductor layer 31B between the die 50 and the punch 55A is suppressed. Further, since the highly ductile conductor layer 31A is pressed from the low-ductile conductor layer 31B side (Z1 side) while being restricted by the die 50, the intrusion of the highly ductile conductor layer 31A between the die 50 and the punch 55A at the outer edge portion of the clad piece 31 is suppressed, and the generation of burrs of the highly ductile conductor layer 31A between the die 50 and the punch 55A is suppressed.

[0057] The manufacturing method of the terminal component 1 according to the embodiment of the manufacturing method of the battery terminal component according to the present invention has been described above. However, the present invention is not limited to the above embodiment, and various modifications are possible without changing the gist of the above embodiment. For example, the step (E) of forming the bottomed hole portion 35D and the step (F) of forming the flange portion may be performed simultaneously.

Industrial Applicability

[0058] The battery terminal component according to the present invention can be used, for example, by connecting to the electrode of a lithium-ion secondary battery.

Explanation of Reference Numerals

[0059] 1: Terminal component 10: Shaft portion 11: Bottomed hole portion 20: Flange portion 30: Clad plate 30A, 31A, 32A, 33A, 34A, 35A: High ductility conductor layer 30B, 31B, 32B, 33B, 34B, 35B: Low ductility conductor layer 31: Clad piece 32, 33, 34, 35: Intermediate body 32C: Protrusion 33C, 34C, 35C: Shaft portion 34D: Intermediate bottomed hole portion 35D: Bottomed hole portion 40, 50, 60, 70, 80, 90: Die 41: Hole 42, 55A, 55B, 65, 75, 85, 95: Punch 43, 59, 69: Guide 51, 61, 71, 81: Vertical hole portion 52, 62, 72, 82: Bottom surface 53, 63, 73, 83: Inner peripheral wall 56: Concave portion for forming protrusion 57, 57A, 57B, 57C, 57D, 67: Inclined surface 66: Concave portion for forming shaft portion 92: Upper surface 200: Battery 201: Case 202: Negative electrode current collector 207, 208: Packing 209: Bus bar

Claims

1. Using a clad plate in which a highly ductile conductor layer and a low ductility conductor layer having lower ductility than the highly ductile conductor layer are laminated and joined in the thickness direction, an axial portion extending in the thickness direction of the clad plate, and a flange portion extending from the axial portion in a direction orthogonal to the thickness direction, a manufacturing method for manufacturing a battery terminal component, comprising: When arranging the clad pieces formed by punching the clad plate in the thickness direction in the lower die, in the lower die, a step (1) of arranging the clad pieces so that the highly ductile conductor layer contacts the bottom surface of the vertical hole portion that opens upward; When the upper die enters the vertical hole portion of the lower die and presses the upper surface of the low ductility conductor layer of the clad piece, in the upper die, a convex portion forming concave portion that opens downward and extends upward for forming a convex portion that becomes the axial portion at the center of the clad piece in the orthogonal direction, plastically deforming the side surface of the clad piece toward the convex portion forming concave portion while restraining the plastic deformation of the side surface of the clad piece by the inner peripheral wall of the vertical hole portion of the lower die, and forming the convex portion inside the convex portion forming concave portion, a step (2). A method for manufacturing a terminal component.

2. On the inner peripheral edge of the inner peripheral wall of the convex portion forming concave portion of the upper die, an inclined surface inclined upward toward the center in the orthogonal direction is provided. The method for manufacturing a terminal component according to claim 1.

3. The gradient of the inclined surface of the inner peripheral edge of the upper die with respect to the bottom surface of the vertical hole portion of the lower die increases toward the center in the orthogonal direction. The method for manufacturing a terminal component according to claim 2.

4. The upper die has a plurality of flat surfaces or curved surfaces that are continuous from the outer peripheral portion at the lower end toward the center in the orthogonal direction, and the gradient of the plurality of flat surfaces or curved surfaces with respect to the bottom surface of the vertical hole portion of the lower die increases toward the center in the orthogonal direction. The method for manufacturing a terminal component according to claim 2.

5. The upper mold has a plurality of conical surfaces that continuously slope upward from the outer peripheral portion at the lower end toward the center in the orthogonal direction, and the plurality of conical surfaces have a taper angle that is smaller toward the upper part. The method for manufacturing a terminal component according to claim 2.

6. In the step (2), when the thickness of the high-ductility conductor layer is TH and the thickness of the low-ductility conductor layer is TL at the outer peripheral edge of the clad piece, the clad piece is extended into the concave portion for forming the convex portion of the upper mold until TL / (TH + TL) ≤ 0.2 is satisfied. The method for manufacturing a terminal component according to claim 1.

7. After the step (2), the method for manufacturing a terminal component according to claim 1 includes a step (3) of extending the convex portion to form the shaft portion.

8. After the step (3), the method for manufacturing a terminal component according to claim 7 includes a step (4) of forming a bottomed hole portion on one end side of the shaft portion.

9. After the step (4), the method for manufacturing a terminal component according to claim 8 includes a step (5) of forming the flange portion that extends radially from the shaft portion by pressing the other end side of the shaft portion opposite to the one end side.

10. After the step (5), the method for manufacturing a terminal component according to claim 9 includes a step (6) of trimming the outermost peripheral portion of the flange portion.

11. The method for manufacturing a terminal component according to claim 10, wherein the steps (1) to (6) are performed by transfer press forming.

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