jig

Abstract

This provides a fixture that allows for easy and efficient connection of adjacent pairs of tabs in multiple battery cells using busbars. [Solution] The jig 10 is used when connecting the two end faces 131 of an adjacent pair of tabs 130 in a plurality of battery cells 110 using a bus bar 60. The jig 10 has a case portion 20 that covers the pair of tabs 130 and has through holes 23 for welding lasers, a pair of side plates 22 (temporary holding portions) for temporarily holding the bus bar 60, and a biasing mechanism 30 that biases the bus bar 60 toward both end faces 131 when the case portion 20, in the state of temporarily holding the bus bar 60, covers the pair of tabs 130.

Description

Technical Field

[0001] This disclosure relates to a jig.

Background Art

[0002] In the method for manufacturing a battery module disclosed in Patent Document 1, a plurality of tabs drawn out from a laminate are connected via a bus bar using a bus bar module and a clamping jig. The bus bar module has a bus bar and a bus bar holder, and is assembled to the battery module so that the partition portion of the bus bar holder enters the gap between the tabs. The clamping jig has a pair of clamping portions and is positioned at a position where it sandwiches a pair of tabs and a bus bar.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the method for manufacturing a battery module of Patent Document 1, when connecting a pair of tabs using a bus bar, it is necessary to perform an operation of inserting the partition portion of the bus bar holder into the gap between the tabs and an operation of positioning the pair of clamping portions of the clamping jig so as to sandwich the pair of tabs and the bus bar, which is time-consuming. Therefore, there is a need for a technique that can easily connect a pair of tabs to a bus bar with good connection.

[0005] An object of this disclosure is to provide a jig that can easily and well connect an adjacent pair of tabs in a plurality of battery cells by a bus bar.

Means for Solving the Problems

[0006] The jig of this disclosure is A jig used when connecting the two end faces of an adjacent pair of tabs in multiple battery cells using a busbar, A case portion that covers the pair of tabs and has through holes for welding lasers, A temporary holding part for temporarily holding the busbar, With the busbar temporarily held by the temporary holding portion and the case portion covering the pair of tabs, a biasing mechanism biases the busbar toward both end faces, It holds. [Effects of the Invention]

[0007] According to this disclosure, a fixture can be provided that allows for easy and efficient connection of adjacent pairs of tabs in multiple battery cells using busbars. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic perspective view showing the jig in Embodiment 1. [Figure 2] Figure 2 is a schematic perspective view showing one end of a plurality of battery cells in Embodiment 1. [Figure 3] Figure 3 is a front view showing a pair of tabs connected to a busbar. [Figure 4] Figure 4 is a front view of the jig shown in Figure 1. [Figure 5] Figure 5 is a plan view of the jig shown in Figure 1. [Figure 6] Figure 6 is a perspective view of the busbar in Embodiment 1. [Figure 7] Figure 7 is a front view showing the busbar temporarily held in place by the jig in Figure 1. [Figure 8] Figure 8 is a plan view showing the busbar temporarily held in place by the jig in Figure 1. [Figure 9] Figure 9 is a front view illustrating the process of covering the case portion of the jig shown in Figure 1 with a pair of tabs. [Figure 10]FIG. 10 is a front view of the case portion of the jig shown in FIG. 1 covered with a pair of tabs. [Figure 11] FIG. 11 is a front view for explaining a step of laser-welding the bus bar and the front end surfaces of the tabs in a state where the jig shown in FIG. 1 is assembled to a pair of tabs. [Figure 12] FIG. 12 is a plan view for explaining a step of laser-welding the bus bar and the front end surfaces of the tabs in a state where the jig shown in FIG. 1 is assembled to a pair of tabs. [Figure 13] FIG. 13 is a front view for explaining a step of detaching the jig shown in FIG. 1 from a pair of tabs after laser welding.

BEST MODE FOR CARRYING OUT THE INVENTION

[0009] <Embodiment 1> In the first embodiment, the present invention is applied to the jig 10 shown in FIG. 1.

[0010] The jig 10 shown in FIG. 1 of the first embodiment is a jig used when connecting both front end surfaces 131 of a pair of adjacent tabs 130 by a bus bar 60 (see FIG. 6 etc.) in the battery module 100 (a plurality of battery cells 110) shown in FIG. 2. FIG. 3 shows a state where the pair of tabs 130 and the bus bar 60 are connected.

[0011] In the following description, regarding the front-rear direction, the F direction in FIGS. 1 and 2 is defined as the front. Regarding the up-down direction, the H direction in FIGS. 1 and 2 is defined as the up. Regarding the left-right direction, the L direction in FIGS. 1 and 2 is defined as the left. Note that each defined direction does not indicate the positional relationship and direction in the actual usage mode.

[0012] (Configuration of Battery Module 100) The battery module 100 is, for example, a lithium-ion battery. As shown in FIG. 2, the battery module 100 includes a plurality (a pair in FIG. 2) of battery cells 110. Between the pair of battery cells 110, for example, a partition material 112 (cushion material) is provided.

[0013] The battery cell 110 has a main body portion 120 and a pair of tabs 130 (a positive electrode tab 130A and a negative electrode tab 130B).

[0014] The main body portion 120 has a flexible outer package 121 having a rectangular shape, and an electrode laminate (not shown) and an electrolytic solution (not shown) sealed within the outer package 121. The electrode laminate is formed by alternately laminating a plurality of positive electrode plates (not shown) and negative electrode plates (not shown) via a separator (not shown). The plurality of positive electrode plates are electrically connected to the positive electrode tab 130A. The plurality of negative electrode plates are electrically connected to the negative electrode tab 130B.

[0015] The pair of tabs 130 are exposed from the main body portion 120 (more specifically, the outer package 121). For example, the positive electrode tab 130A is exposed so as to protrude from an edge (upper edge) on one side of the main body portion 120 (more specifically, the outer package 121). For example, the negative electrode tab 130B is exposed so as to protrude from an edge (lower edge) on the other side opposite to the edge on one side of the main body portion 120 (more specifically, the outer package 121).

[0016] The tab 130 is made of, for example, a metal material having conductivity. The tab 130 has a flat plate shape with a polygon (e.g., hexagon) in cross-sectional view (when viewed from the protruding direction). The tip surface of the tab 130 is, for example, a plane orthogonal to the protruding direction (vertical direction) of the tab 130. The thickness (plate thickness) of the tab 130 is, for example, 0.5 mm or more and 3 mm or less. The tab 130 has two flat surfaces 132 and four inclined surfaces 133. The inclined surfaces 133 are inclined with respect to the flat surfaces 132. On both plate surfaces of the tab 130, the two inclined surfaces 133 are continuous on the front and rear sides of the flat surface 132.

[0017] The tab 130 has a pair of notches 134 formed therein. The notches 134 are used to position the jig 10 and the tab 130 by fitting the projections 25 of the jig 10, which will be described later, into them. The notches 134 are recessed from one flat surface 132 towards the other flat surface 132. The notches 134 are formed near the center of the tab 130 in the protruding direction (vertical direction). The notches 134 are elongated in the direction perpendicular to the protruding direction of the tab 130 and the thickness direction of the tab 130 (front-to-back direction). The notches 134 are formed in the tab 130, extending from one inclined surface 133 to the other inclined surface 133 that sandwiches the flat surface 132. In cross-sectional view (viewed from the front-to-back direction), the notches 134 are wedge-shaped.

[0018] (Configuration of jig 10) As shown in Figures 1, 4, and 5, the jig 10 comprises a case portion 20 and a biasing mechanism 30.

[0019] The case portion 20 is made of a non-conductive material such as resin or ceramic. The case portion 20 has a top plate 21 and a pair of side plates 22. The top plate 21 is a flat plate with a rectangular (e.g., square) shape in plan view. The pair of side plates 22 correspond to an example of the "temporary holding portion" of this disclosure. The pair of side plates 22 extend downward from each of the edges of the top plate 21. The side plates 22 are flat plates with a rectangular (e.g., square) shape in side view. The surfaces of the pair of side plates 22 are parallel. The front-to-back width of the side plates 22 is the same as the front-to-back width of the top plate 21.

[0020] The top plate 21 has a pair of through holes 23 formed therein for use with a welding laser. The pair of through holes 23 are formed inward relative to each of the left and right edges of the top plate 21. The through holes 23 penetrate the top plate 21 in the thickness direction. In plan view, the through holes 23 are rectangular in shape, elongated in the front-to-back direction.

[0021] A projection 25 is formed on the inner wall surface 24 of the side plate 22 (the wall surface on the other side plate 22 side). The projection 25 fits into the notch 134 of the tab 130, thereby positioning the case portion 20 and the tab 130. The projection 25 protrudes inward in the left-right direction (towards the other side plate 22 side), that is, in a direction perpendicular to the insertion direction of the pair of tabs 130 into the case portion 20. The projection 25 is formed at a position slightly below the vertical center of the side plate 22. The projection 25 is formed over the entire width direction of the side plate 22. On the pair of side plates 22, each projection 25 is formed at the same height.

[0022] The cross-section of the projection 25 (viewed from the front-rear direction) is triangular. For example, the angle at the tip of the projection 25 in its cross-section is obtuse.

[0023] The distance between the inner wall surfaces 24 of a pair of side plates 22 (the wall surface on the other side plate 22 side) is approximately the same as, or slightly larger than, the distance between the outer surfaces (outer flat surfaces 132 in the left-right direction) of a pair of tabs 130, i.e., it is the same, slightly larger, or slightly smaller.

[0024] The biasing mechanism 30 has a pair of elastic bodies 31. The elastic bodies 31 are configured as coil springs. The pair of elastic bodies 31 are arranged on the underside of the top plate 21. One end of each elastic body 31 is fixed to the underside of the top plate 21 such that its axis is parallel to the vertical direction. The pair of elastic bodies 31 are positioned at the center in the left-right direction on the underside of the top plate 21. The pair of elastic bodies 31 are spaced apart in the front-rear direction. The pair of elastic bodies 31 are positioned at the same distance from the center in the front-rear direction on the underside of the top plate 21.

[0025] The elastic body 31 expands and contracts in the vertical direction. The direction of expansion and contraction of the elastic body 31 is parallel to the direction in which the pair of tabs 130 are inserted into the case portion 20.

[0026] (Bus bar 60) The busbar 60 shown in Figure 6 is a component that electrically connects a pair of adjacent tabs 130. The busbar 60 is connected to both end faces 131 of the pair of adjacent tabs 130 by laser welding. The busbar 60 is made of, for example, a metal such as copper (Cu) or aluminum (Al), or a clad material of copper (Cu) and aluminum (Al). The busbar 60 is, for example, a flat plate with a rectangular (e.g., square) shape in plan view.

[0027] The front-to-back width of the busbar 60 is approximately the same as, for example, the front-to-back width of the top plate 21, that is, the same, slightly larger, or slightly smaller. The left-to-right width of the busbar 60 is approximately the same as, that is, the same, slightly larger, or slightly smaller than, the distance between each outer surface (outer flat surface 132 in the left-to-right direction) of the pair of tabs 130. As shown in Figure 3, the left and right sides of the busbar 60 are flush with each outer surface (outer flat surface 132 in the left-to-right direction) of the pair of tabs 130.

[0028] (Steps for connecting the busbar 60 to a pair of tabs 130) First, as shown in Figures 7 and 8, the busbar 60 is temporarily held in place by the jig 10. For example, the busbar 60 is temporarily held in place by being sandwiched between a pair of side plates 22 of the case portion 20. Specifically, a pair of back-to-back sides 61 of the busbar 60 are in contact with the inner walls of the pair of side plates 22. At this time, the busbar 60 may or may not be in contact with the elastic body 31.

[0029] Next, as shown in Figure 9, the case portion 20, with the busbar 60 temporarily held in place, is placed over the adjacent pair of tabs 130 (positive electrode tab 130A and negative electrode tab 130B) on the battery module 100. As the pair of tabs 130 penetrate the case portion 20, the protrusions 25 on the inner wall surface 24 of the case portion 20 fit into the notches 134 of the tabs 130, as shown in Figure 10. This positions the case portion 20 and the tabs 130.

[0030] As the pair of tabs 130 enter the case portion 20, the busbar 60 is pushed by the two end faces 131 of the pair of tabs 130 and moves towards the top plate 21 within the case portion 20. At this time, both sides 61 of the busbar 60 slide along the two inner wall surfaces 24 of the case portion 20. As a result, the busbar 60 moves along the inner wall surface 24 of the case portion 20 while maintaining its orientation relative to the case portion 20. This makes it easier to bring the busbar 60 into contact with the two end faces 131 of the pair of tabs 130 when the jig 10 is assembled to the pair of tabs 130, as shown in Figure 10.

[0031] Furthermore, when the pair of tabs 130 enter the case portion 20, it is preferable that the outer surfaces (flat surfaces 132 on the left and right sides) of the pair of tabs 130 slide against the inner wall surfaces 24 of the case portion 20.

[0032] The busbar 60 moves towards the top plate 21 within the case portion 20, while elastically deforming the elastic body 31. Therefore, as shown in Figure 10, when the jig 10 is assembled to the pair of tabs 130 (with the case portion 20 covering the pair of tabs 130), the busbar 60 is biased toward both end faces 131 by the elastic body 31. This allows the busbar 60 to be held in a state pressed against the end faces 131 of the tabs 130.

[0033] Next, as shown in Figures 11 and 12, a laser is shone through the through hole 23 at a position on the busbar 60 that overlaps with the tip surface 131 of the tab 130. This welds the busbar 60 and both tip surfaces 131 of the pair of tabs 130. For example, the laser is shone along the longitudinal direction (front-to-back direction) of the through hole 23. The welded portion 70 is formed between the busbar 60 and the tip surfaces 131 of the pair of tabs 130. The welded portion 70 is formed along the front-to-back width direction of the tab 130.

[0034] The through-hole 23 is formed in a position that overlaps vertically with the tip surface 131 of the tab 130 (more specifically, the center of the front-to-back width direction and the center of the left-to-right width direction of the tip surface 131) when the case portion 20, in which the busbar 60 is temporarily held, is covering the pair of tabs 130. Therefore, by irradiating the through-hole 23 from above, the laser is more likely to hit the position on the busbar 60 that overlaps with the tip surface 131 of the tab 130.

[0035] Next, as shown in Figure 13, the jig 10 is detached from the pair of tabs 130. Specifically, by moving the jig 10 upward relative to the pair of tabs 130, the projection 25 comes out of the notch 134, and the jig 10 detaches from the pair of tabs 130. In this way, the process of connecting the busbar 60 to the pair of tabs 130 is completed.

[0036] (Effects and Benefits) The jig 10 of this embodiment 1 is used when connecting the two end faces 131 of an adjacent pair of tabs 130 with a bus bar 60 in a plurality of battery cells 110. The jig 10 has a case portion 20 that covers the pair of tabs 130 and has through holes 23 for welding lasers, a pair of side plates 22 (temporary holding portions) for temporarily holding the bus bar 60, and a biasing mechanism 30 that biases the bus bar 60 toward both end faces 131 when the case portion 20, in the state of temporarily holding the bus bar 60, covers the pair of tabs 130.

[0037] Thus, the jig 10 can temporarily hold the busbar 60 with a pair of side plates 22, allowing the case portion 20 to be placed over the pair of tabs 130 while the busbar 60 is temporarily held. This makes it easier to assemble the jig 10 to the pair of tabs 130. Furthermore, the jig 10 has a biasing mechanism 30 that biases the busbar 60 toward both end faces 131 of the pair of tabs 130, so that the busbar 60 can be laser-welded while pressed against the end faces 131 of the tabs 130. This suppresses the occurrence of gaps or voids between the busbar 60 and the end faces 131 of the tabs 130, enabling good laser welding. For example, it can suppress an increase in electrical resistance at the welded area and suppress a decrease in the strength of the welded area. Therefore, by using the jig 10 of this embodiment 1, adjacent pairs of tabs 130 in multiple battery cells 110 can be easily and effectively connected by the busbar 60.

[0038] In the jig 10 of this embodiment 1, a notch 134 is formed in the tab 130. A projection 25 is formed on the inner wall surface 24 of the case portion 20, which fits into the notch 134 to position the case portion 20 and the tab 130. With this configuration, when assembling the jig 10 to a pair of tabs 130, the projection 25 on the inner wall surface 24 of the case portion 20 fits into the notch 134 of the tab 130, making it easy to position the case portion 20 and the tab 130.

[0039] In the jig 10 of this embodiment 1, the through hole 23 is formed at a position that overlaps with the tip surface 131 when the busbar 60 is temporarily held by the pair of side plates 22 and the case portion 20 covers the pair of tabs 130. With this configuration, by irradiating the busbar 60 with a laser through the through hole 23, the laser is more easily irradiated to the position on the busbar 60 that overlaps with the tip surface 131 of the tab 130. As a result, the busbar 60 can be laser welded well to the tip surface 131 of the tab 130.

[0040] In the jig 10 of this embodiment 1, the through hole 23 is formed at a position that coincides with the center of the width direction (front-to-back width direction and left-to-right width direction) of the tip surface 131 when the busbar 60 is temporarily held by the pair of side plates 22 and the case portion 20 covers the pair of tabs 130. With this configuration, by irradiating the busbar 60 with a laser through the through hole 23, the laser is more easily irradiated at a position that coincides with the center of the width direction (front-to-back width direction and left-to-right width direction) of the tip surface 131 of the tab 130. As a result, the busbar 60 can be laser welded to the tip surface 131 of the tab 130 more effectively.

[0041] In the jig 10 of this embodiment 1, both sides 61 of the busbar 60 are configured to slide along the inner wall surface 24 of the case portion 20. With this configuration, when assembling the jig 10 to the pair of tabs 130, the sliding of both sides 61 of the busbar 60 along the inner wall surface 24 of the case portion 20 allows the busbar 60 to move along the inner wall surface 24 of the case portion 20 while maintaining its orientation relative to the case portion 20. This makes it easier to bring the busbar 60 into contact with both end faces 131 of the pair of tabs 130 when the jig 10 is assembled to the pair of tabs 130.

[0042] <Other Embodiments> The present invention is not limited to the embodiments described above and in the drawings, and the following embodiments, for example, are also included in the technical scope of the present invention. (1) In the above embodiment 1, the pair of tabs 130 were exposed from opposite edges of the main body 120 (more specifically, the outer casing 121), but they may be exposed from the same edge. (2) In the above embodiment 1, the tab 130 was a flat plate with a polygonal shape (e.g., hexagonal) when viewed in cross-section (from the direction of projection), but it may also be quadrilateral (rectangle, square) when viewed in cross-section (from the direction of projection). (3) In the above embodiment 1, the elastic body 31 was configured as a coil spring, but it may be configured as other spring members (such as leaf springs) or elastic members such as rubber. (4) In the above embodiment 1, the bus bar 60 was temporarily held in place by being sandwiched between a pair of side plates 22 of the case portion 20, but its downward detachment from the case portion 20 may be restricted by being caught from above by at least one of the protrusions 25. (5) In the above embodiment 1, the case portion 20 and the tab 130 were positioned by the interlocking of the protrusion 25 of the case portion 20 and the notch 134 of the tab 130. However, the jig 10 may be positioned by the clamping force of the pair of side plates 22 of the jig 10, which each clamp the flat surfaces 132 of the pair of tabs 130, without providing the protrusion 25 and the notch 134. (6) In the above embodiment 1, the projection 25 provided on the inner wall surface 24 of the case portion 20 was wedge-shaped and convex in the left-right direction, but it may be a curved projection, such as a hemispherical shape. The notch 134 of the tab 130 may also be a curved recess, such as a hemispherical shape, rather than a wedge-shaped recess. (7) In the above embodiment 1, the biasing mechanism 30 had a pair of elastic bodies 31, but the number of elastic bodies 31 is not particularly limited and may be one, three or more.

[0043] The examples described herein are for illustrative purposes only and should not be construed as limiting the invention. Although the invention has been described with examples of typical embodiments, the language used in the description and illustrations of the invention should be understood as descriptive and illustrative, not limiting. As detailed herein, modifications are possible within the scope or essence of the invention without departing in any way. While specific structures, materials, and embodiments have been referenced in this detailed description of the invention, the invention is not intended to be limited to the disclosures herein, but rather to encompass all functionally equivalent structures, methods, and uses within the scope of the claims. [Explanation of Symbols]

[0044] 10: Jig 20: Case section 21: Top plate 22: Side plate (temporary support part) 23: Through hole 24: Interior wall surface 25: Protrusion 30: Biasing mechanism 31: Elastic body 60: Bus bar 61: Side view 70: Welded section 100: Battery Module 110: Battery cell 112: Partition material 120: Main body 121: Exterior 130: Tab 130A: Positive Tab 130B: Negative electrode tab 131: Tip surface 132: Flat surface 133: Slope 134: Notch

Claims

1. A jig used when connecting the two end faces of an adjacent pair of tabs in multiple battery cells using a busbar, A case portion that covers the pair of tabs and has through holes for welding lasers, A temporary holding part for temporarily holding the busbar, With the busbar temporarily held by the temporary holding portion and the case portion covering the pair of tabs, a biasing mechanism biases the busbar toward both end faces, A jig having

2. The aforementioned tab has a notch formed therein. The jig according to claim 1, wherein a projection is formed on the inner wall surface of the case portion to fit into the notch portion, thereby positioning the case portion and the tab.

3. The jig according to claim 1 or 2, wherein the through hole is formed at a position that overlaps with the tip surface when the busbar is temporarily held by the temporary holding portion and the case portion covers the pair of tabs.

4. The jig according to claim 1 or 2, wherein the through hole is formed at a position that coincides with the center in the width direction of the tip surface when the busbar is temporarily held by the temporary holding portion and the case portion covers the pair of tabs.

5. The jig according to claim 1 or claim 2, wherein both sides of the busbar are configured to slide against the inner wall surface of the case portion.

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