Method for manufacturing flexible bus bar

Abstract

Provided is a method for manufacturing a flexible bus bar, whereby even in a complicated shape, quality can be stabilized and manufacturing efficiency can be improved. A plurality of conductive material foils (1) are laminated (see fig. 1(a)). Both side portions (an upper fixed portion (2) and a lower fixed portion (3)) of the plurality of laminated conductive material foils (1) are fixed, and the upper fixed portion (2), the lower fixed portion (3), and an unfixed portion (4) are formed on the plurality of conductive material foils (1) (see fig. 1(c)). Then, a flexible bus bar (5) having a predetermined shape is cut out from the plurality of conductive material foils (1) in which the upper fixed portion (2), the lower fixed portion (3), and the unfixed portion (4) are formed (see fig. 1(c) and 1(d)).

Description

Flexible busbar manufacturing method

[0001] The present invention relates to a method for manufacturing a flexible busbar.

[0002] It is generally known that flexible bus bars are used to connect electrically conductive components (for example, batteries installed in electric vehicles, hybrid cars, etc.). For example, a flexible bus bar such as that described in Patent Document 1 is known. The flexible bus bar described in Patent Document 1 is manufactured by stacking and fixing thin, flexible conductive foils made of a metal such as copper that have been cut into a predetermined shape in advance.

[0003] International Publication No. 2012 / 118046

[0004] Here, the conventional method for manufacturing the flexible bus bar will be described in more detail with reference to FIG.

[0005] To manufacture a flexible busbar 100 as shown in Fig. 5(c), first, a sheet of conductive material foil 101 is prepared, which is a thin, flexible metal such as copper, and has a vertically elongated rectangular shape (straight shape) as shown in Fig. 5(a). Then, a complex shape (non-straight shape) as shown by dashed line S100 in Fig. 5(a) is cut out of the prepared conductive material foil 101 using a wire or the like. This produces a flexible busbar piece 102 having a complex shape (non-straight shape) as shown in Fig. 5(b).

[0006] A plurality of flexible busbar pieces 102 manufactured in this manner are stacked one on top of the other so that the upper end surfaces 102a of the flexible busbar pieces 102 are aligned and the lower end surfaces 102b of the flexible busbar pieces 102 are aligned, as shown in FIG. 5(b). Then, by fixing the upper end surfaces 102a of the flexible busbar pieces 102 shown in FIG. 5(b), an upper fixed portion 103 is formed as shown in FIG. 5(c). By fixing the lower end surfaces 102b of the flexible busbar pieces 102 shown in FIG. 5(b), a lower fixed portion 104 is formed as shown in FIG. 5(c). This results in the manufacture of a flexible busbar 100 having a non-fixed portion 105 formed between the upper fixed portion 103 and the lower fixed portion 104, as shown in FIG. 5(c). The non-fixed portion 105 is flexible.

[0007] However, in this manufacturing method, as shown in Fig. 5(b), multiple flexible busbar pieces 102 are stacked so that the upper end faces 102a of the flexible busbar pieces 102 and the lower end faces 102b of the flexible busbar pieces 102 are aligned, which can lead to misalignment during stacking. This can result in unstable quality of the flexible busbar 100 shown in Fig. 5(c), which can lead to reduced manufacturing efficiency. This problem is particularly pronounced when manufacturing flexible busbar pieces 102 with complex shapes (non-straight shapes) such as those shown in Fig. 5(b).

[0008] In view of the above problems, an object of the present invention is to provide a method for manufacturing a flexible busbar that can stabilize quality and improve manufacturing efficiency even when the flexible busbar has a complex shape.

[0009] The above object of the present invention can be achieved by the following means: Note that the parentheses indicate reference symbols of embodiments to be described later, but the present invention is not limited to these.

[0010] The method for manufacturing a flexible busbar according to claim 1 includes the steps of: laminating a plurality of conductive materials (conductive material foils 1) (see FIG. 1(a)); fixing both side portions (upper fixing portions 2, lower fixing portions 3) of the laminated conductive materials (conductive material foils 1) to form fixed portions (upper fixing portions 2, lower fixing portions 3) and non-fixed portions (4) in the plurality of conductive materials (conductive material foils 1) (see FIG. 1(c)); and cutting out a flexible busbar (5) of a predetermined shape from the plurality of conductive materials (conductive material foils 1) having the fixed portions (upper fixing portions 2, lower fixing portions 3) and the non-fixed portions (4) formed therein (see FIGS. 1(c) and 1(d)).

[0011] The method for manufacturing a flexible busbar according to claim 2 includes the steps of: laminating a plurality of conductive materials (conductive material foils 1A) (see FIG. 4(a)); fixing both side portions (upper fixing portions 2, lower fixing portions 3) of the laminated conductive materials (conductive material foils 1A) to form fixing portions (upper fixing portions 2, lower fixing portions 3) and non-fixing portions (4) in the plurality of conductive materials (conductive material foils 1A) (see FIG. 4(c)); and cutting out a plurality of flexible busbars (5) of predetermined shapes from the plurality of conductive materials (conductive material foils 1A) having the fixing portions (upper fixing portions 2, lower fixing portions 3) and the non-fixing portions (4) formed therein (see FIGS. 4(c) and 4(d)).

[0012] The flexible busbar manufacturing method according to claim 3 is characterized in that, in the flexible busbar manufacturing method according to claim 1 or 2, the non-fixed portion (4) of the cut flexible busbar (5) having a predetermined shape is formed in a rectangular shape, and the lengths of the diagonals (4a, 4b) are the same (see FIG. 2(a-2)).

[0013] The method for manufacturing a flexible busbar according to claim 4 is the method for manufacturing a flexible busbar according to claim 1 or 2, characterized in that the cut-out flexible busbar (5) of a predetermined shape has protrusions (upper protrusions 2 b, lower protrusions 3 b) or recesses formed therein.

[0014] The method for manufacturing a flexible busbar according to claim 5 is the method for manufacturing a flexible busbar according to claim 1 or 2, characterized in that the fixing portions (upper fixing portion 2, lower fixing portion 3) are formed by thermal welding.

[0015] Next, the effects of the present invention will be described with reference to the drawings. Note that the reference symbols in parentheses are those of the embodiments described below, but the present invention is not limited to these.

[0016] According to the inventions of claims 1 and 2, flexible bus bars (5) of a predetermined shape are cut out from a plurality of conductive materials (conductive material foils 1, 1A) formed with fixed portions (upper fixed portion 2, lower fixed portion 3) and non-fixed portions (4), so there is no need to prepare pieces with complex shapes (non-straight shapes) as in conventional manufacturing methods. This eliminates the possibility of misalignment occurring when stacked.

[0017] Therefore, according to the present invention, even if the shape is complex, it is possible to stabilize the quality and improve the manufacturing efficiency.

[0018] Furthermore, according to the invention as defined in claim 2, since a plurality of pieces can be cut out at once, it is possible to reduce the number of manufacturing steps.

[0019] According to the invention of claim 3, the non-fixed portion (4) of the flexible busbar (5) having a predetermined shape is formed in a rectangular shape, and the lengths of the diagonals (4a, 4b) are the same (see FIG. 2(a-2)). Therefore, when the flexible busbar (5) is bent for use, no difference in the bending distance occurs regardless of the direction in which the flexible busbar (5) is bent. As a result, no wrinkles are formed in the non-fixed portion (4) due to bending.

[0020] According to the fourth aspect of the present invention, it is possible to easily accommodate the formation of protrusions (upper protrusions 2b, lower protrusions 3b) or recesses, stabilize quality, and improve manufacturing efficiency.

[0021] According to the fifth aspect of the present invention, there is no possibility that the solder used in soldering or the like will melt when heat is applied to the flexible bus bar 5. Furthermore, there is no possibility that the desired resistance value of the flexible bus bar 5 will not be obtained due to the influence of the material used in soldering or the like.

[0022] 1A to 1D are explanatory diagrams illustrating a manufacturing method for a flexible busbar according to an embodiment of the present invention. 1A-1 is a front view of a flexible busbar manufactured by the manufacturing method according to the embodiment, 1A-2 is a front view of the flexible busbar shown in 1A-1 with a non-bonded portion extracted, 1B-1 is a front view of a flexible busbar manufactured by a conventional manufacturing method, and 1B-2 is a front view of the flexible busbar shown in 1B-1 with a non-bonded portion extracted. 1B-1 is a front view of a flexible busbar manufactured by the manufacturing method according to the embodiment, and 1B-2 is a front view of the flexible busbar shown in 1B-1 with a non-bonded portion extracted. 1C is a front view of a flexible busbar manufactured by the manufacturing method according to the embodiment, with protrusions provided. 1D-1 are explanatory diagrams illustrating a method for manufacturing a plurality of flexible busbars by the manufacturing method according to the embodiment. 1D-1 are explanatory diagrams illustrating a conventional method for manufacturing a flexible busbar.

[0023] A method for manufacturing a flexible busbar according to one embodiment of the present invention will now be described in detail with reference to the drawings. In the following description, when referring to directions such as up, down, left, and right, they refer to the directions as viewed from the front of the illustration.

[0024] <Description of Flexible Busbar Manufacturing Method> The flexible busbar manufacturing method according to this embodiment can stabilize quality and improve manufacturing efficiency even when the flexible busbar has a complex shape. Specifically, the flexible busbar is manufactured as follows.

[0025] First, as shown in FIG. 1( a), a stack of multiple thin, flexible, rectangular (straight) conductive material foils 1 made of a metal such as copper is prepared. Here, as shown in FIG. 1( b), a complex (non-straight) shape is assumed to be cut out from the stack of multiple conductive material foils 1, as indicated by dashed line S1 in FIG. 1( b). This cutting is assumed to be performed so that the right side surface 1a of the multiple laminated conductive material foils 1 is parallel to the right long side S1a of the complex (non-straight) shape indicated by dashed line S1 in FIG. 1( b), and the left side surface 1b of the multiple laminated conductive material foils 1 is parallel to the left long side S1b of the complex (non-straight) shape indicated by dashed line S1 in FIG. Note that at this stage, the cutting is merely assumed and has not yet been performed.

[0026] Next, the upper end surfaces 1c of the multiple laminated conductive material foils 1 shown in Fig. 1(b) are thermally welded to form an upper fixed portion 2 as shown in Fig. 1(c), and the lower end surfaces 1d of the multiple laminated conductive material foils 1 shown in Fig. 1(b) are thermally welded to form a lower fixed portion 3 as shown in Fig. 1(c). As a result, a non-fixed portion 4 is formed between the upper fixed portion 2 and the lower fixed portion 3 as shown in Fig. 1(c). This non-fixed portion 4 is flexible.

[0027] Next, in this state, the flexible bus bar 5 is cut out along the intended cutting line S1 shown in Fig. 1(c) using a wire, press, laser, or the like, thereby producing the flexible bus bar 5 shown in Fig. 1(d).

[0028] Therefore, as explained above, if both ends (upper fixing portion 2 and lower fixing portion 3 shown in FIG. 1(c)) of a plurality of laminated conductive material foils 1 are fixed and then cut out, there is no need to align pieces with complex shapes (non-straight shapes) as in the conventional manufacturing method. Therefore, it is possible to eliminate the possibility of misalignment occurring when stacking, as in the conventional manufacturing method.

[0029] Therefore, according to this embodiment, the quality of the flexible bus bar 5 shown in FIG. 1(d) can be stabilized, and further, the manufacturing efficiency can be improved.

[0030] Therefore, according to this embodiment, even if the shape is complex, it is possible to stabilize the quality and improve the manufacturing efficiency.

[0031] In this embodiment, when manufacturing the flexible busbar 5 shown in FIG. 2(a-1), the non-fixed portion 4 is cut out into a rectangular shape as shown in FIG. 2(a-2). That is, the right side surface 1a of the laminated conductive material foil 1 shown in FIG. 1(b) is parallel to the right long side S1a of the complex shape (non-straight shape) indicated by the dashed line S1 in FIG. 1(b), and the left side surface 1b of the laminated conductive material foil 1 is parallel to the left long side S1b of the complex shape (non-straight shape) indicated by the dashed line S1 in FIG. 1(b). This allows the non-fixed portion 4 to be cut out into a rectangular shape as shown in FIG. 2(a-2). As shown in FIG. 2(a-2), the diagonals 4a and 4b of this non-fixed portion 4 have the same length. In this way, when the flexible bus bar 5 is bent for use, as shown in Fig. 2(a-2), the diagonal lines 4a and 4b have the same length, so no difference in the bending distance occurs regardless of the direction in which the flexible bus bar 5 is bent. Therefore, no wrinkles are formed in the non-fixed portion 4 due to bending.

[0032] That is, as described above, the conventional flexible busbar 100 is configured as shown in FIG. 2(b-1). As shown in FIG. 2(b-1), the non-fixed portion 105 of the flexible busbar 100 has a parallelogram shape as shown in FIG. 2(b-2). This parallelogram has diagonal lines 105a and 105b of different lengths, as shown in FIG. 2(b-2). Therefore, when the flexible busbar 100 is bent for use, the diagonal lines 105a and 105b have different lengths, as shown in FIG. 2(a-2). Therefore, when the flexible busbar 100 is bent for use, the way it bends varies depending on the bending direction, as shown in FIG. 2(a-2). Therefore, differences in bending distances are likely to occur, and wrinkles due to bending may occur in the non-fixed portion 105. Such wrinkles are unsightly and may cause problems when connecting electrically conductive components (e.g., batteries installed in electric vehicles, hybrid cars, etc.) due to size mismatch or other reasons.

[0033] However, if the lengths of the diagonal lines 4a and 4b of the non-fixed portion 4 are the same as in this embodiment, the above problem does not occur.

[0034] Furthermore, by forming the non-fixed portion 4 so that the diagonal lines 4a and 4b have the same length as each other as described above, the vertical length L1 of the non-fixed portion 4 shown in Fig. 2(a-1) can be made longer than the vertical length L2 of the non-fixed portion 105 shown in Fig. 2(b-1). This allows the flexibility (range of motion) of the flexible busbar 5 to be wider than that of the conventional flexible busbar 100.

[0035] Furthermore, the amount of multiple laminated conductive material foils 1 remaining after cutting out the flexible bus bars 5 from the multiple laminated conductive material foils 1 is also less than in the past, thereby reducing material waste.

[0036] The flexible busbar 5 manufactured as described above is used with the upper fixing portion 2 having an upper bolt hole 2a penetrating therethrough and the lower fixing portion 3 having a lower bolt hole 3a penetrating therethrough, as shown in FIG. 3 . Specifically, bolts (not shown) are inserted into the upper bolt hole 2a and the lower bolt hole 3a to connect electrically conductive components (e.g., batteries installed in electric vehicles, hybrid cars, etc.) using the flexible busbar 5 shown in FIG. 3 . At this time, if bolts (not shown) are inserted into the upper bolt hole 2a and the lower bolt hole 3a to fasten the flexible busbar 5, a load may be applied to the upper fixing portion 2 and the lower fixing portion 3 shown in FIG. 3 , causing the upper fixing portion 2 and the lower fixing portion 3 to be pressed and crushed, potentially making it impossible to connect the electrically conductive components. To avoid this, an upper protrusion 2b may be provided on the upper end surface of the upper fixing portion 2 and a lower protrusion 3b may be provided on the lower end surface of the lower fixing portion 3, as shown in FIG. 3 , so that the upper fixing portion 2 and the lower fixing portion 3 can be hooked onto the above-mentioned components. It should be noted that the upper and lower projections 2b and 3b are not limited to these, and recesses formed of concave notches may also be provided.

[0037] Thus, in order to provide such upper protrusions 2 b and lower protrusions 3 b or recesses (not shown), conventional manufacturing methods require that the upper protrusions 2 b and lower protrusions 3 b or recesses (not shown) be provided when cutting out the conductive material foil 101 shown in Figure 5 (a) using a wire or the like. Therefore, when a plurality of cut-out pieces are stacked, there is a possibility that misalignment will occur when attempting to align the upper protrusions 2 b and lower protrusions 3 b or recesses (not shown).

[0038] However, in this embodiment, both ends of multiple laminated conductive material foils 1 (upper fixing portion 2 and lower fixing portion 3 shown in Figure 1 (c)) can be fixed, and then the upper protrusions 2b and lower protrusions 3b, or recesses not shown, can be cut out, so there is no possibility of the above-mentioned misalignment occurring.

[0039] Therefore, even when an upper protrusion 2b and a lower protrusion 3b as shown in FIG. 3 or a recess not shown is provided, it can be easily accommodated, and quality can be stabilized and manufacturing efficiency can be improved.

[0040] <Explanation of Modifications> The shapes and the like shown in the present embodiment are merely examples, and various modifications and changes are possible within the scope of the gist of the present invention as described in the claims. For example, in the present embodiment, an example of manufacturing one flexible bus bar 5 is shown, but the manufacturing method described above also makes it possible to manufacture multiple flexible bus bars 5 at once. This point will be specifically described with reference to FIG. 4.

[0041] As shown in FIG. 4( a), multiple laminated sheets of conductive material foil 1A are prepared, each having a horizontally elongated rectangular shape (straight shape) and made of a flexible metal such as copper. Here, as shown in FIG. 4( b), multiple complex shapes (non-straight shapes) are assumed to be cut out from the laminated conductive material foil 1A, as indicated by dashed line S1 in FIG. 4( b). This cutting is assumed to be performed so that the right side surface 1Aa of the laminated conductive material foil 1A is parallel to the right long side S1a of the complex shape (non-straight shape) indicated by dashed line S1 in FIG. 4( b), and the left side surface 1Ab of the laminated conductive material foil 1A is parallel to the left long side S1b of the complex shape (non-straight shape) indicated by dashed line S1 in FIG. At this stage, the cutting is merely assumed and the foils have not yet been cut out.

[0042] Next, the upper end surfaces 1Ac of the multiple laminated conductive material foils 1A shown in Fig. 4(b) are thermally welded to form upper fixed portions 2 as shown in Fig. 4(c), and the lower end surfaces 1Ad of the multiple laminated conductive material foils 1 shown in Fig. 4(b) are thermally welded to form lower fixed portions 3 as shown in Fig. 4(c). As a result, non-fixed portions 4 are formed between the upper fixed portions 2 and the lower fixed portions 3 as shown in Fig. 4(c). Note that these non-fixed portions 4 are flexible.

[0043] Next, in this state, the flexible bus bars 5 are cut out along the multiple dashed lines S1 shown in Fig. 4(c) using a wire, press, laser, or the like, thereby producing multiple flexible bus bars 5 as shown in Fig. 4(d).

[0044] Therefore, in this way, similar to the above, it is possible to stabilize the quality and improve the manufacturing efficiency even if the shape is complicated.

[0045] Furthermore, since multiple pieces can be cut out at once, the number of manufacturing steps can be reduced.

[0046] Furthermore, in this embodiment, an example has been shown in which the upper fixing portion 2 and the lower fixing portion 3 are formed by thermal welding, but this is not limiting and they may also be formed using solder or the like. However, thermal welding is preferable. If solder or the like is used to form them, the wax used in the solder or the like may melt when heat is applied to the flexible bus bar 5, and further, the desired resistance value for the flexible bus bar 5 may not be obtained due to the influence of the materials used in the solder or the like. For this reason, thermal welding is preferable.

[0047] REFERENCE SIGNS LIST 1, 1A Conductive material foil (conductive material) 2 Upper fixed portion (fixed portion) 2b Upper protrusion (protrusion) 3 Lower fixed portion (fixed portion) 3b Lower protrusion (protrusion) 4 Non-fixed portion 4a, 4b Diagonal line 5 Flexible bus bar

Claims

1. A method for manufacturing a flexible busbar, comprising the steps of: stacking a plurality of conductive materials; bonding both side portions of the stacked conductive materials to form bonded portions and non-bonded portions in the plurality of conductive materials; and cutting out a flexible busbar of a predetermined shape from the plurality of conductive materials with the bonded portions and non-bonded portions formed therein.

2. A method for manufacturing a flexible busbar, comprising the steps of: stacking a plurality of conductive materials; bonding both side portions of the stacked conductive materials to form bonded portions and non-bonded portions in the plurality of conductive materials; and cutting out a plurality of flexible busbars of a predetermined shape from the plurality of conductive materials with the bonded portions and non-bonded portions formed therein.

3. A method for manufacturing a flexible busbar according to claim 1 or 2, wherein the non-bonded portions of the cut flexible busbar of a predetermined shape are formed in a rectangular shape with the lengths of the diagonals being the same.

4. A method for manufacturing a flexible busbar according to claim 1 or 2, wherein the cut flexible busbar of a predetermined shape has protrusions or recesses formed thereon.

5. A method for manufacturing a flexible busbar according to claim 1 or 2, wherein the fixed portion is formed by thermal welding.

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