Busbar laminate

Abstract

The present invention pertains to a busbar laminate (10) comprising: a first busbar structure (11) including at least one layer of a plate-like busbar having a predetermined width and extending in a lengthwise direction; and a second busbar structure (12) provided on the first busbar structure (11) and having a branch structure which extends in a direction different from the lengthwise direction via a branch part relative to the lengthwise direction of the first busbar structure (11). The second busbar structure (12) has an overlapped part (13) in which the first busbar structure (11) and the second busbar structure (12) overlap with each other in the thickness direction, and which has a predetermined width and extends parallel to the lengthwise direction of the first busbar structure (11). The overlapped part (13) has a welded part extending in the thickness direction such that the first busbar structure (11) and the second busbar structure (12) are welded to each other, and the branch part includes a part or the whole of the welded part.

Description

Busbar laminate

[0001] The present invention relates to a bus bar laminate used for branching and connecting an automotive wire harness or the like to various electrical components.

[0002] A busbar structure in which busbars are branched in multiple directions is used to branch and connect automotive wire harnesses and the like to various electrical components. A busbar structure in which busbars are branched in multiple directions efficiently branches power conducted from an input busbar constituting the busbar structure to multiple busbars connected to the electrical components, also constituting the busbar structure. As wire harnesses become denser and electrical components become more functional, various busbar structures have been proposed.

[0003] A busbar structure in which busbars are branched in multiple directions is formed by connecting the multiple busbars by welding. Patent Document 1 proposes a busbar structure in which a welded portion of a terminal member is sandwiched between pattern portions of two stacked busbars and welding is performed by supplying energy from the surface of the pattern portion of one of the busbars. Patent Document 1 also discloses a busbar structure in which, in order to reduce the energy density supplied to the weld, the pattern portion of one of the busbars is shifted so that a part of the welded portion of the terminal member is exposed, and energy is supplied from the surface of the pattern portion of the shifted busbar and from the surface of the exposed welded portion of the tab terminal member to weld the busbars.

[0004] However, in the busbar structure described in Patent Document 1, in which the welded portion of the terminal member is sandwiched between the pattern portions of two stacked busbars, using a thick busbar increases the amount of heat dissipated from the busbar during welding, thereby increasing the energy required for welding. Therefore, if the amount of heat dissipated from the busbar increases and the energy required for welding increases, there is a concern that the welding efficiency will decrease and the welding quality will deteriorate. Furthermore, since Patent Document 1 describes a busbar branch direction being changed via the terminal member interposed between the two busbars, it is desirable to use a busbar structure with a branching structure that allows the busbar itself to determine the branching direction without using a terminal member.

[0005] As a busbar structure having such a branched structure, Patent Document 2 proposes a branched busbar in which at least two conductive layers are laminated and a part of the conductive layer is separated and branched at a predetermined branch point. In Patent Document 2, a part of the conductive layer is folded to form the branch point, and each conductive layer is integrally formed by mechanical fixing, welding, or the like.

[0006] However, when a branch point is formed by folding a portion of a conductive layer, if a strong load is applied to the fold during the production process, cracks or breakage may occur at the branch point, resulting in a decrease in yield. Furthermore, when each conductive layer is fastened with a bolt or other fastener, holes for the bolt must be drilled into the conductive layer, which limits the use of wide conductive layers. Therefore, there is a need for the development of a new busbar structure that does not require mechanical fastening, provides a stronger connection between each busbar at the branch point, and allows the busbar itself to determine the branch direction.

[0007] JP 2000-150013 A JP 2023-530398 A

[0008] In view of the above circumstances, an object of the present invention is to provide a busbar laminate having a branching structure in which branch points are connected more firmly than before and the branching direction can be determined by the busbars themselves.

[0009] A busbar laminate according to an embodiment of the present invention comprises: a first busbar structure including at least one plate-shaped busbar layer having a predetermined width and extending in a longitudinal direction; and a second busbar structure provided on the first busbar structure and having a branch structure extending in a direction different from the longitudinal direction of the first busbar structure via a branch portion, wherein the second busbar structure has an overlapping portion in which the first busbar structure and the second busbar structure overlap each other in a thickness direction, the overlapping portion having a predetermined width and extending parallel to the longitudinal direction of the first busbar structure, the overlapping portion having a weld portion extending in the thickness direction so that the first busbar structure and the second busbar structure are welded to each other, and the branch portion includes a part or the entirety of the weld portion.

[0010] In one embodiment of the present invention, the branch portion includes a part of the weld portion, and the weld portion is formed of a plurality of lines parallel to the longitudinal direction of the first busbar structure in a plan view.

[0011] In one embodiment of the present invention, in the second busbar structure, the overlapping portion and the branch portion are integrally formed on the same busbar.

[0012] In one embodiment of the present invention, in the second busbar structure, the busbar having the branch portion is formed as a separate body, and the busbar having the branch portion extends in a direction different from the longitudinal direction of the first busbar structure via the branch portion.

[0013] In one embodiment of the present invention, the first busbar structure includes at least two layers of the plate-like busbars, the busbars being stacked one on top of the other in the thickness direction, and the first busbar structure has welds extending in the thickness direction so that the busbars are welded to each other.

[0014] In one embodiment of the present invention, the branch portion includes the entire welded portion, and the welded portion is formed, in a plan view, by an enclosed line surrounded by two lines that face each other parallel to the longitudinal direction of the first busbar structure and two lines that face each other in a direction different from the longitudinal direction of the first busbar structure.

[0015] In one embodiment of the present invention, the second busbar structure has an L-shape or a T-shape in plan view.

[0016] In one embodiment of the present invention, a width of a portion of the second busbar structure that extends in a direction different from the longitudinal direction of the first busbar structure via a branch portion is different from a width of the overlapping portion.

[0017] In one embodiment of the present invention, the branch portion further includes another weld portion different from the weld portion formed of a plurality of lines parallel to the longitudinal direction of the first busbar structure in a plan view.

[0018] In one embodiment of the present invention, the branch portion includes a part of the weld portion, and the branch portion includes a weld portion formed of a plurality of lines in a direction different from the longitudinal direction of the first busbar structure.

[0019] In one embodiment of the present invention, the branch portion includes a part of the weld portion, and the branch portion includes a weld portion formed, in a plan view, by an enclosure line surrounded by two lines facing each other parallel to the longitudinal direction of the first busbar structure and two lines facing each other in a direction different from the longitudinal direction of the first busbar structure.

[0020] In one embodiment of the present invention, the second busbar structure has the overlapping portion on only one side in the longitudinal direction of the first busbar structure relative to the branch portion.

[0021] According to an embodiment of the present invention, there is provided a busbar laminate comprising: a first busbar structure including at least one plate-shaped busbar layer having a predetermined width and extending in a longitudinal direction; and a second busbar structure provided on the first busbar structure and having a branched structure extending in a direction different from the longitudinal direction of the first busbar structure via a branch portion, wherein the second busbar structure has an overlapping portion having a predetermined width and extending parallel to the longitudinal direction of the first busbar structure, in which the first busbar structure and the second busbar structure overlap each other in a thickness direction, the overlapping portion having a weld portion extending in the thickness direction so as to weld the first busbar structure to the second busbar structure, and the branch portion including a part or the entirety of the weld portion, thereby providing a busbar laminate with a branched structure in which the branch points are more firmly connected than before and the branch direction can be determined by the busbars themselves. Furthermore, since there are no folds at the branch points, cracks and breakage at the branch points can be prevented.

[0022] In one embodiment of the busbar laminate according to the present invention, the branch portion includes a part of the weld portion, and the weld portion is formed of a plurality of lines parallel to the longitudinal direction of the first busbar structure in a plan view. This facilitates the formation of the weld portion and improves the connection strength between the first busbar structure and the second busbar structure.

[0023] In one embodiment of the busbar laminate according to the present invention, in the second busbar structure, the overlapping portion and the branching portion are integrally formed on the same busbar, which makes it easy to design a branching structure.

[0024] According to one embodiment of the busbar laminate of the present invention, in the second busbar structure, the busbar having the branch portion is formed as a separate body and extends via the branch portion in a direction different from the longitudinal direction of the first busbar structure. Therefore, the busbar having the overlapping portion and the busbar having the branch portion can be designed using different materials depending on the intended use. Furthermore, the width of the busbar having the branch portion can be appropriately designed depending on the intended use.

[0025] According to one embodiment of the busbar laminate of the present invention, the first busbar structure includes at least two layers of the plate-shaped busbars, and the busbars are stacked one on top of the other in the thickness direction. The first busbar structure has welds extending in the thickness direction so that the busbars are welded to each other. This improves the connection strength between the busbars and also enables the thickness of the busbar laminate to be increased.

[0026] In one embodiment of the busbar laminate according to the present invention, the branch portion includes the entire weld portion, and the weld portion is formed, in a plan view, by an enclosed line surrounded by two lines that face each other parallel to the longitudinal direction of the first busbar structure and two lines that face each other in a direction different from the longitudinal direction of the first busbar structure, thereby further improving the connection strength of the branch portion.

[0027] In one embodiment of the busbar laminate according to the present invention, the second busbar structure has a generally L-shaped or T-shaped planar shape, which facilitates the design of a right-angle branching direction. Furthermore, since the second busbar structure has a T-shaped planar shape, the overlapping portion of the second busbar structure is formed over the entire surface of the first busbar structure, making it possible to provide a busbar laminate having a branching structure with a flat outermost surface.

[0028] In one embodiment of the busbar laminate according to the present invention, the width of the portion of the second busbar structure that extends in a direction different from the longitudinal direction of the first busbar structure via a branch portion is different from the width of the overlapping portion, and this makes it possible to appropriately design the magnitude of the current that flows through the portion that extends in a direction different from the longitudinal direction via the branch portion depending on the intended use.

[0029] In one embodiment of the busbar laminate according to the present invention, the second busbar structure has the overlapping portion on only one side of the first busbar structure in the longitudinal direction relative to the branch portion. This makes it possible to reduce the cross-sectional area of ​​the busbar laminate across the branch portion, thereby enabling reduction (optimization) of material in accordance with the current capacity.

[0030] FIG. 1 is a schematic perspective view of a busbar laminate according to a first embodiment of the present invention. FIG. 2 is a schematic perspective view of a busbar laminate according to a second embodiment of the present invention. FIG. 3 is a schematic perspective view of a busbar laminate according to a third embodiment of the present invention. FIG. 4 is a schematic perspective view of a busbar laminate according to a fourth embodiment of the present invention. FIG. 5 is a schematic perspective view of a busbar laminate according to a fifth embodiment of the present invention. FIG. 6 is a schematic perspective view of a busbar laminate according to a sixth embodiment of the present invention. FIG. 7 is a schematic perspective view of a busbar laminate according to a seventh embodiment of the present invention. FIG. 8 is a schematic perspective view of a busbar laminate according to an eighth embodiment of the present invention. FIG. 9 is a schematic perspective view of a busbar laminate according to a ninth embodiment of the present invention.

[0031] The busbar laminate according to each embodiment of the present invention will be described below. Note that Figures 1 to 9 are schematic perspective views of the busbar laminate according to the first to ninth embodiments of the present invention.

[0032] 1 , a busbar laminate 10 according to a first embodiment includes a first busbar structure 11 including at least one layer of plate-shaped busbars having a predetermined width W1 and extending in the longitudinal direction, and a second busbar structure 12 provided on the first busbar structure 11 and having a branch structure extending with a predetermined width W2B perpendicular to the longitudinal direction of the first busbar structure 11 via a branch portion R1. More specifically, the first busbar structure 11 includes at least two layers of plate-shaped busbars, and has a two-layer structure in which a first busbar 11a and a second busbar 11b are stacked and overlap each other in the thickness direction as the plate-shaped busbars.

[0033] (First busbar structure) In the first busbar structure 11, the first busbar 11a and the second busbar 11b have the same width W1 and are both plate-like members having a longitudinal direction and a lateral direction (width direction) in a plan view. In addition, the first busbar 11a and the second busbar 11b have the same plate thickness.

[0034] The longitudinal direction of the first busbar 11a is the direction of current flow through the first busbar 11a. The longitudinal direction of the second busbar 11b is the direction of current flow through the second busbar 11b. That is, the longitudinal direction of the first busbar structure 11 corresponds to the longitudinal directions of the first busbar 11a and the second busbar 11b.

[0035] The first busbar structure 11 has welds L1 extending in the thickness direction so that each busbar, i.e., the first busbar 11 a and the second busbar 11 b, are welded to each other. The welds L1 are formed of multiple lines parallel to the longitudinal direction of the first busbar structure 11 in a plan view.

[0036] (Second Busbar Structure) The second busbar structure 12 has an overlapping portion 13 extending parallel to the longitudinal direction of the first busbar structure 11, with the first busbar structure 11 and the second busbar structure 12 overlapping each other in the thickness direction and having a predetermined width W2A. That is, the overlapping portion 13 has a three-layer structure in which the second busbar structure 12, the first busbar 11a, and the second busbar 11b are stacked and overlapped in the thickness direction. In the second busbar structure 12, the overlapping portion 13 and the branch portion R1 are integrally formed on the same busbar (one busbar), resulting in a branched structure in which the overlapping portion 13 and the branch portion R1 are provided on the same surface. The second busbar structure 12 has a substantially L-shaped shape in a plan view, and the second busbar structure 12 also conducts current in a direction branching perpendicular to the longitudinal direction of the overlapping portion 13 via the branch portion R1.

[0037] The overlapping portion 13 has welds L1 extending in the thickness direction so as to weld the first busbar structure 11 and the second busbar structure 12 to each other. The branch portion R1 includes a portion of the welds L1, and the welds L1 are formed of multiple lines parallel to the longitudinal direction of the first busbar structure 11 in a plan view. That is, in the busbar laminate 10, linear welds L1 are formed on the same straight line along the longitudinal direction of the first busbar structure 11 in the first busbar structure 11 that does not have the overlapping portion 13 region, and in the first busbar structure 11 and the second busbar structure 12 that have the overlapping portion 13 region.

[0038] The width W1 of the first busbar structure 11 is the same as the width W2A of the overlapping portion 13. Therefore, the busbar laminate 10 has a laminated structure in which the first busbar structure 11 and the overlapping portion 13 of the second busbar structure 12 are overlapped with each other with the same width.

[0039] The welded portion L1 may be formed by, for example, laser welding or wobbling welding. Examples of materials for the first bus bar 11 a, the second bus bar 11 b, and the second bus bar structure 12 include copper or copper alloys such as tough pitch copper, oxygen-free copper, and brass, and aluminum alloys such as 6000 series aluminum.

[0040] As described above, in the busbar laminate 10, the overlapping portion 13 has the weld portion L1 extending in the thickness direction so as to weld the first busbar structure 11 and the second busbar structure 12 to each other, and the branch portion R1 includes a part of the weld portion L1, thereby improving the connection strength of the branch portion R1. Furthermore, the first busbar structure 11 includes two layers of plate-shaped first busbars 11a and second busbars 11b, which are stacked so as to overlap each other in the thickness direction, and the first busbar structure 11 has the weld portion L1 extending in the thickness direction so as to weld the first busbars 11a and the second busbars 11b to each other. This improves the connection strength between the first busbars 11a and the second busbars 11b, and allows the busbar laminate 10 to be thicker.

[0041] Furthermore, in the busbar laminate 10, linear welds L1 are continuously formed in the same straight line along the longitudinal direction of the first busbar structure 11 in the first busbar structure 11 that does not have the overlapping portion 13 region, and in the first busbar structure 11 and the second busbar structure 12 that have the overlapping portion 13 region. This makes it easy to form the welds L1, and improves the connection strength not only between the first busbar 11a and the second busbar 11b, but also between the first busbar structure 11 and the second busbar structure 12.

[0042] In the busbar laminate 10, the overlapping portion 13 and the branching portion R1 are integrally formed on the same busbar in the second busbar structure 12, and the second busbar structure 12 has a generally L-shaped shape in plan view, providing a busbar structure with a branching structure that allows for easy design of the branching direction. Furthermore, in the busbar laminate 10, the welded portions L1 are formed by multiple linear laser welds, which prevents voids from forming in the welded portions L1 and improves the electrical connectivity and connection strength between the first busbar 11a and the second busbar 11b and between the first busbar structure 11 and the second busbar structure 12.

[0043] In the second busbar structure 12, a width W2B of a portion extending perpendicularly to the longitudinal direction of the first busbar structure 11 via the branch portion R1 may be the same as or different from the width W2A of the overlapping portion 13. By making the width W2B and the width W2A different, the magnitude of the current flowing in the portion of the second busbar structure 12 extending in a direction different from the longitudinal direction of the first busbar structure 11 via the branch portion R1 can be designed appropriately depending on the application purpose.

[0044] <Second Embodiment> Next, a busbar laminate according to a second embodiment of the present invention will be described. In the busbar laminate according to the first embodiment, the overlapping portion and the branch portion are integrally formed in the same busbar in the second busbar structure. However, in the busbar laminate according to the second embodiment, the busbar having the branch portion is formed as a separate body in the second busbar structure. In Fig. 2, components common to the busbar laminate according to the first embodiment shown in Fig. 1 are denoted by the same reference numerals, and their functions are also assumed to be the same. Since the common components are the same as those in the first embodiment described above, their description will be omitted.

[0045] As shown in FIG. 2 , the busbar laminate 20 according to the second embodiment includes a first busbar structure 11 having a two-layer structure including a first busbar 11 a and a second busbar 11 b, and a second busbar structure 12 provided on the first busbar structure 11 and having a branch structure that extends with a predetermined width W4B perpendicular to the longitudinal direction of the first busbar structure 11 via a branch portion R2, in a direction different from the longitudinal direction of the first busbar structure 11.

[0046] In the second busbar structure 12, a plate-shaped third busbar 12a without a branch portion R2 and a plate-shaped fourth busbar 12b with a branch portion R2 are formed separately. A portion of a side surface of the fourth busbar 12b having a long side parallel to the longitudinal direction is in contact with a side surface of the third busbar 12a having a long side parallel to the short direction (width direction), thereby ensuring electrical continuity between the third busbar 12a and the fourth busbar 12b. The second busbar structure 12 has a branch structure in which the plate-shaped third busbar 12a without a branch portion R2 and the fourth busbar 12b having a branch portion R2 different from that of the third busbar 12a are connected to each other, and the second busbar structure 12 has a substantially L-shaped shape in a plan view. The second busbar structure 12 passes current in both the longitudinal direction of the third busbar 12a and the longitudinal direction of the fourth busbar 12b.

[0047] The first busbar structure 11 has welds L2 extending in the thickness direction so that the first busbar 11a and the second busbar 11b are welded to each other, and the second busbar structure 12 has welds L2 extending in the thickness direction so that the first busbar structure 11 and the second busbar structure 12 are welded to each other. The branch portions R2 include part of the welds L2, and the welds L2 are formed of multiple lines parallel to the longitudinal direction of the first busbar structure 11 in a plan view. That is, in the busbar laminate 20, multiple linear welds L2 are formed in the same straight line from one longitudinal end of the third busbar 12a (the side not in contact with the fourth busbar 12b) to one end of the first busbar structure 11 that does not overlap with the second busbar structure 12 (the side not in contact with the fourth busbar 12b).

[0048] Examples of materials for the third bus bar 12a and the fourth bus bar 12b include copper or copper alloys such as tough pitch copper, oxygen-free copper, and brass, and aluminum alloys such as 6000 series aluminum.

[0049] As described above, in the busbar laminate 20, the plate-shaped third busbar 12a without the branch portion R2 and the plate-shaped fourth busbar 12b with the branch portion R2 are formed separately in the second busbar structure 12, and the fourth busbar 12b extends via the branch portion R2 in a direction different from the longitudinal direction of the first busbar structure 11 with respect to the longitudinal direction of the third busbar 12a. This allows the third busbar 12a and the fourth busbar 12b to be designed using different materials depending on the intended use. Furthermore, the width W4B of the fourth busbar 12b can be designed appropriately depending on the intended use, and the width W4A of the third busbar 12a and the width W4B of the fourth busbar 12b extending in the branch direction of the second busbar structure 12 can be designed to be different widths.

[0050] <Third Embodiment> Next, a busbar laminate according to a third embodiment of the present invention will be described. In the busbar laminates according to the first and second embodiments, the branch portion includes a portion of the weld portion, and the weld portion is formed by multiple lines parallel to the longitudinal direction of the first busbar structure in a plan view. However, in the busbar laminate according to the third embodiment, the branch portion includes the entire weld portion, and the weld portion is formed by an encircling line in a plan view. In Fig. 3, components common to the busbar laminate according to the first embodiment shown in Fig. 1 are assigned the same reference numerals, and their functions are also assumed to be the same. Since the common components are the same as those in the first embodiment described above, their description will be omitted.

[0051] As shown in FIG. 3 , a busbar laminate 30 according to the third embodiment includes a first busbar structure 11 having a two-layer structure including a first busbar 11 a and a second busbar 11 b, and a second busbar structure 12 provided on the first busbar structure 11 and having a branch structure that extends with a predetermined width perpendicular to the longitudinal direction of the first busbar structure 11 via a branch portion R3, in a direction different from the longitudinal direction of the first busbar structure 11.

[0052] In the second busbar structure 12, the branch portion R3 includes the entire weld portion L3, and the weld portion L3 is formed in a plan view by a rectangular enclosure surrounded by two lines facing each other parallel to the longitudinal direction of the first busbar structure 11 and two lines facing each other in the direction in which the branch structure of the second busbar structure extends (a direction different from the longitudinal direction of the first busbar structure 11). The second busbar structure 12 has a branch structure in which the overlapping portion 13 and the branch portion R3 are provided on the same surface, and the shape of the second busbar structure 12 is approximately L-shaped in a plan view. The second busbar structure 12 also passes current in a direction branching perpendicular to the longitudinal direction of the overlapping portion 13 via the branch portion R3.

[0053] In the bus bar laminate 30, the welded portion L3 is also formed by, for example, laser welding, and may also be formed by wobbling welding.

[0054] As described above, in the busbar laminate 30, the welded portion L3 is formed within the branch portion R3, which is provided on the same surface as the overlapping portion 13 where the first busbar structure 11 and the second busbar structure 12 are stacked, thereby improving the connection strength of the branch portion R3.

[0055] <Fourth Embodiment> Next, a busbar laminate according to a fourth embodiment of the present invention will be described. In the busbar laminate according to the first embodiment, only linear welds were formed on the same straight line along the longitudinal direction of the first busbar structure in the first busbar structure that did not have an overlapping region and in the first and second busbar structures that did have overlapping regions. However, in the busbar laminate according to the fourth embodiment, the branch portion further includes a weld formed by an enclosing line surrounded by two lines that are parallel to and opposed to the longitudinal direction of the first busbar structure and two lines that are opposed in a direction different from the longitudinal direction of the first busbar structure in a plan view. Note that in FIG. 4, components common to the busbar laminate according to the first embodiment shown in FIG. 1 are denoted by the same reference numerals and have the same functions. Because the common components are the same as those in the first embodiment described above, a description thereof will be omitted.

[0056] As shown in FIG. 4 , a busbar laminate 40 according to the fourth embodiment includes a first busbar structure 11 having a two-layer structure including a first busbar 11 a and a second busbar 11 b, and a second busbar structure 12 provided on the first busbar structure 11 and having a branch structure extending with a predetermined width perpendicular to the longitudinal direction of the first busbar structure 11 via a branch portion R4.

[0057] In the busbar laminate 40, linear welds L4a are formed on the same straight line along the longitudinal direction of the first busbar structure 11 in the first busbar structure 11 that does not have the overlapping portion 13 and the second busbar structure 12 that has the overlapping portion 13. The branch portion R4 further includes another weld L4b that is different from the weld L4a formed by a plurality of lines parallel to the longitudinal direction of the first busbar structure 11 in a plan view. The weld L4b is formed by an encircling line surrounded by two lines that are parallel to and facing the longitudinal direction of the first busbar structure 11 and two lines that are facing in a direction different from the longitudinal direction of the first busbar structure 11 in a plan view.

[0058] The second busbar structure 12 has a branched structure in which the overlapping portion 13 and the branching portion R4 are provided on the same surface, and the shape of the second busbar structure 12 is generally I-shaped in plan view relative to the first busbar structure 11. That is, in the second busbar structure 12, the longitudinal direction of the overlapping portion 13 corresponds to the branching direction (branching direction) in a direction different from the longitudinal direction of the first busbar structure 11 via the branching portion R5. The second busbar structure 12 also passes current in the branching direction.

[0059] Fifth Embodiment Next, a busbar laminate according to a fifth embodiment of the present invention will be described. In the busbar laminate according to the first embodiment, the branch portions have welds formed of multiple lines parallel to the longitudinal direction of the first busbar structure in a plan view. However, in the busbar laminate according to the fifth embodiment, the branch portions have welds formed of multiple lines in a direction different from the longitudinal direction of the first busbar structure. In Fig. 5, components common to the busbar laminate according to the first embodiment shown in Fig. 1 are denoted by the same reference numerals, and their functions are also assumed to be the same. Since the common components are the same as those in the first embodiment described above, their description will be omitted.

[0060] As shown in FIG. 5 , a busbar laminate 50 according to the fourth embodiment includes a first busbar structure 11 having a two-layer structure including a first busbar 11a and a second busbar 11b, and a second busbar structure 12 provided on the first busbar structure 11 and having a branch structure that extends with a predetermined width perpendicular to the longitudinal direction of the first busbar structure 11 via a branch portion R5 in a direction different from the longitudinal direction of the first busbar structure 11.

[0061] The branch portion R5 includes a part of the weld portion, and the first busbar structure 11 and the second busbar structure 12 are each formed with weld portions L5a, L5b, which are formed of multiple lines parallel to the longitudinal direction of the first busbar structure 11 in a plan view, and the weld portions L5a, L5b are not continuous with each other but are formed at a distance from each other.

[0062] The branch portion R5 of the second busbar structure 12 has a weld portion L5c formed at it, which is different from the weld portions L5a and L5b formed of multiple lines parallel to the longitudinal direction of the first busbar structure 11 in a plan view. The branch portion R5 includes the weld portion L5c formed of multiple lines in a direction different from (perpendicular to) the longitudinal direction of the first busbar structure 11. The second busbar structure 12 has a branch structure in which the overlapping portion 13 and the branch portion R5 are provided on the same surface, and the shape of the second busbar structure 12 is approximately L-shaped in a plan view. The second busbar structure 12 also passes current in a direction branching perpendicular to the longitudinal direction of the overlapping portion 13 via the branch portion R5.

[0063] <Sixth Embodiment> Next, a busbar laminate according to a sixth embodiment of the present invention will be described. In the busbar laminate according to the first embodiment, only linear welds were formed on the same straight line along the longitudinal direction of the first busbar structure in the first busbar structure that did not have an overlapping region, and in the first busbar structure and the second busbar structure that did have an overlapping region. However, in the busbar laminate according to the sixth embodiment, the branch portions further include welds formed of multiple lines in a direction different from the longitudinal direction of the first busbar structure. In FIG. 6 , components common to the busbar laminate according to the first embodiment shown in FIG. 1 are denoted by the same reference numerals, and their functions are also assumed to be the same. Because the common components are the same as those in the first embodiment described above, a description thereof will be omitted.

[0064] As shown in FIG. 6 , a busbar laminate 60 according to the sixth embodiment includes a first busbar structure 11 having a two-layer structure including a first busbar 11 a and a second busbar 11 b, and a second busbar structure 12 provided on the first busbar structure 11 and having a branch structure that extends with a predetermined width perpendicular to the longitudinal direction of the first busbar structure 11 via a branch portion R6, in a direction different from the longitudinal direction of the first busbar structure 11.

[0065] In the busbar laminate 60, linear welds L6a are formed on the same straight line along the longitudinal direction of the first busbar structure 11 in the first busbar structure 11 that does not have the overlapping portion 13 region, and in the first busbar structure 11 and the second busbar structure 12 that have the overlapping portion 13 region. In addition, the branch portion R6 further includes welds L6b different from the welds L6a that are formed of multiple lines parallel to the longitudinal direction of the first busbar structure 11 in a plan view, and further includes welds L6b that are formed of multiple lines in a direction different from (perpendicular to) the longitudinal direction of the first busbar structure 11.

[0066] The second busbar structure 12 has a branched structure in which the overlapping portion 13 and the branching portion R6 are provided on the same surface, and the shape of the second busbar structure 12 is generally L-shaped in a plan view. The second busbar structure 12 also passes current in a direction branching perpendicular to the longitudinal direction of the overlapping portion 13 via the branching portion R6.

[0067] <Seventh Embodiment> Next, a busbar laminate according to a seventh embodiment of the present invention will be described. In the busbar laminate according to the second embodiment, the branch portion includes a weld formed by a plurality of lines parallel to the longitudinal direction of the first busbar structure in a plan view. However, in the busbar laminate according to the seventh embodiment, the branch portion instead includes a weld formed by an enclosing line surrounded by two lines parallel to and facing the longitudinal direction of the first busbar structure and two lines facing in a direction different from the longitudinal direction of the first busbar structure in a plan view. In FIG. 7 , components common to the busbar laminate according to the first embodiment shown in FIG. 1 are denoted by the same reference numerals and have the same functions. Because the common components are the same as those in the first embodiment described above, a description thereof will be omitted.

[0068] As shown in FIG. 7 , a busbar laminate 70 according to the fourth embodiment includes a first busbar structure 11 having a two-layer structure including a first busbar 11a and a second busbar 11b, and a second busbar structure 12 provided on the first busbar structure 11 and having a branch structure that extends with a predetermined width perpendicular to the longitudinal direction of the first busbar structure 11 via a branch portion R7, in a direction different from the longitudinal direction of the first busbar structure 11.

[0069] The branch portion R7 includes a part of a welded portion, and in the second busbar structure 12, a plate-shaped third busbar 12a without the branch portion R7 and a plate-shaped fourth busbar 12b with the branch portion R7 are formed separately. The second busbar structure 12 has a branched structure in which the plate-shaped third busbar 12a without the branch portion R7 and the fourth busbar 12b with the branch portion R7 different from that of the third busbar 12a are connected to each other, and the second busbar structure 12 has a substantially L-shaped shape in a plan view. The second busbar structure 12 passes current in both the longitudinal direction of the third busbar 12a and the longitudinal direction of the fourth busbar 12b.

[0070] The first busbar structure 11 and the second busbar structure 12 are each formed with welds L7a, L7b, which are formed of multiple lines parallel to the longitudinal direction of the first busbar structure 11 in a plan view, and the welds L7a, L7b are not continuous with each other but are formed spaced apart. The welds L7a are also formed spaced apart from each other.

[0071] In plan view, the branch portion R7 of the second busbar structure 12 has a weld portion L7c formed thereat that is different from the weld portions L7a and L7b formed by a plurality of lines parallel to the longitudinal direction of the first busbar structure 11. The branch portion R7 includes a weld portion L5c formed by a plurality of lines in a direction different from (perpendicular to) the longitudinal direction of the first busbar structure 11. In plan view, the weld portion L7c is formed by an encircling line surrounded by two lines facing each other parallel to the longitudinal direction of the first busbar structure 11 and two lines facing each other in a direction different from the longitudinal direction of the first busbar structure 11.

[0072] Eighth Embodiment Next, a busbar laminate according to an eighth embodiment of the present invention will be described. In the busbar laminate according to the second embodiment, only linear welds were formed on the same straight line along the longitudinal direction of the first busbar structure in the first busbar structure that did not have an overlapping region and in the first and second busbar structures that did have overlapping regions. However, in the busbar laminate according to the eighth embodiment, the branch portion further includes a weld formed by an enclosing line surrounded by two lines that are parallel to and opposed to the longitudinal direction of the first busbar structure and two lines that are opposed in a direction different from the longitudinal direction of the first busbar structure in a plan view. In FIG. 8 , components common to the busbar laminate according to the first embodiment shown in FIG. 1 are denoted by the same reference numerals and have the same functions. Because the common components are the same as those in the first embodiment described above, a description thereof will be omitted.

[0073] As shown in FIG. 8 , a busbar laminate 80 according to the eighth embodiment includes a first busbar structure 11 having a two-layer structure including a first busbar 11a and a second busbar 11b, and a second busbar structure 12 provided on the first busbar structure 11 and having a branch structure that extends with a predetermined width perpendicular to the longitudinal direction of the first busbar structure 11 via a branch portion R4 in a direction different from the longitudinal direction of the first busbar structure 11.

[0074] In the second busbar structure 12, a plate-shaped third busbar 12a without a branch portion R8 and a plate-shaped fourth busbar 12b with a branch portion R8 are formed separately. The second busbar structure 12 has a branch structure in which the plate-shaped third busbar 12a without a branch portion R8 and the fourth busbar 12b with a branch portion R8 different from that of the third busbar 12a are connected to each other, and the second busbar structure 12 has a substantially L-shaped shape in a plan view. The second busbar structure 12 passes current in both the longitudinal direction of the third busbar 12a and the longitudinal direction of the fourth busbar 12b.

[0075] In the busbar laminate 80, linear welds L8a are formed on the same straight line along the longitudinal direction of the first busbar structure 11 in the first busbar structure 11 that does not have the overlapping portion 13 and the second busbar structure 12 that has the overlapping portion 13. The branch portion R8 also includes another weld L8b that is different from the weld L8a formed by a plurality of lines parallel to the longitudinal direction of the first busbar structure 11 in a plan view. The weld L8b is formed by an encircling line surrounded by two lines that are parallel to and facing the longitudinal direction of the first busbar structure 11 and two lines that are facing in a direction different from the longitudinal direction of the first busbar structure 11 in a plan view.

[0076] <Ninth embodiment> Next, a busbar laminate according to a ninth embodiment of the present invention will be described. In the busbar laminates according to the first to third and fifth to eighth embodiments, the shape of the second busbar structure is generally L-shaped in plan view. However, in the busbar laminate according to the ninth embodiment, the shape of the second busbar structure is generally T-shaped in plan view. In Fig. 9, components common to the busbar laminate according to the first embodiment shown in Fig. 1 are assigned the same reference numerals, and their functions are also assumed to be the same. Since the common components are the same as those in the first embodiment described above, their description will be omitted.

[0077] As shown in FIG. 9 , a busbar laminate 90 according to the ninth embodiment includes a first busbar structure 11 having a two-layer structure including a first busbar 11 a and a second busbar 11 b, and a second busbar structure 12 provided on the first busbar structure 11 and having a branch structure that extends with a predetermined width perpendicular to the longitudinal direction of the first busbar structure 11 via a branch portion R4 in a direction different from the longitudinal direction of the first busbar structure 11.

[0078] The second busbar structure 12 has a branched structure in which the overlapping portion 13 and the branching portion R9 are provided on the same surface, and the shape of the second busbar structure 12 is generally T-shaped in plan view. As a result, the overlapping portion 13 of the second busbar structure 12 is formed on the entire surface of the first busbar structure 11, making it possible to provide a busbar laminate having a branched structure with a flat outermost surface.

[0079] In the bus bar laminate 90, the welded portion (not shown) may be formed in the same manner as in the other embodiments, and it is sufficient that the branch portion R9 includes a part or the entire welded portion.

[0080] Next, other embodiments of the busbar structure of the present invention will be described. In the busbar structures according to the above embodiments, the first busbar structure is a two-layer structure including a first busbar and a second busbar. However, instead of this, the first busbar structure may be a single-layer structure including only the first busbar.

[0081] Furthermore, the first bus bar, the second bus bar, and the second bus bar structure (including the third bus bar and the fourth bus bar) may be made of the above-mentioned material and then have their surfaces plated.

[0082] Furthermore, in the busbar structure according to the above-described embodiment, when the busbar structure includes a plurality of linear welds that are parallel to the longitudinal direction of the first busbar structure in a plan view, the linear welds are formed of two lines that are parallel to the longitudinal direction of the first busbar structure in a plan view, but instead, the linear welds may be formed of one line or three or more lines.

[0083] In the busbar structures according to the third, fourth, seventh, and eighth embodiments, the branch portion includes the welded portion L formed by a rectangular enclosing line in plan view. However, instead, the branch portion may be formed by various enclosing lines, such as a circular, elliptical, trapezoidal, or polygonal enclosing line in plan view.

[0084] In the above-described embodiment, the extending direction of the branching structure of the second busbar structure is perpendicular to the longitudinal direction of the first busbar structure, but the extending direction of the branching structure of the second busbar structure is not limited to being perpendicular, and may be any direction different from the longitudinal direction of the first busbar structure.

[0085] The busbar laminate of the present invention has a branching structure in which the branch points are connected more firmly than before and the branching direction can be determined by the busbar itself. This makes the laminate effective for branching connections to various electrical components, such as automotive wire harnesses, for example.

[0086] 10, 20, 30, 40, 50, 60, 70, 80, 90 busbar laminate 11 first busbar structure 12 second busbar structure 11a first busbar 11b second busbar 12a third busbar 12b fourth busbar 13 overlapping portion

Claims

1. A busbar laminate comprising: a first busbar structure including at least one plate-shaped busbar layer having a predetermined width and extending in the longitudinal direction; and a second busbar structure provided on the first busbar structure and having a branch structure extending in a direction different from the longitudinal direction of the first busbar structure via a branch portion, wherein the second busbar structure has an overlapping portion where the first busbar structure and the second busbar structure overlap each other in the thickness direction, the overlapping portion having a predetermined width and extending parallel to the longitudinal direction of the first busbar structure, the overlapping portion having a weld portion extending in the thickness direction so that the first busbar structure and the second busbar structure are welded to each other, and the branch portion includes part or all of the weld portion.

2. The busbar laminate according to claim 1, wherein the branch portion includes a part of the welded portion, and the welded portion is formed of a plurality of lines that are parallel to the longitudinal direction of the first busbar structure in a plan view.

3. The busbar laminate according to claim 1 or 2, wherein in the second busbar structure, the overlapping portion and the branch portion are integrally formed on the same busbar.

4. The busbar laminate according to claim 1 or 2, wherein in the second busbar structure, the busbar having the branch portion is formed as a separate body, and the busbar having the branch portion extends in a direction different from the longitudinal direction of the first busbar structure via the branch portion.

5. The busbar laminate according to claim 1 or 2, wherein the first busbar structure includes at least two layers of the plate-like busbars, the busbars being stacked one on top of the other in the thickness direction, and the first busbar structure has welds extending in the thickness direction so that the busbars are welded to each other.

6. The busbar laminate according to claim 1, wherein the branch portion includes the entire welded portion, and the welded portion is formed, in plan view, by an enclosed line surrounded by two lines that face each other parallel to the longitudinal direction of the first busbar structure and two lines that face each other in a direction different from the longitudinal direction of the first busbar structure.

7. The busbar laminate according to claim 1 or 2, wherein the second busbar structure has a substantially L-shaped or T-shaped shape in plan view.

8. The busbar laminate according to claim 1 or 2, wherein the width of a portion of the second busbar structure that extends in a direction different from the longitudinal direction of the first busbar structure via a branch portion is different from the width of the overlapping portion.

9. The busbar laminate according to claim 2, wherein the branch portion further includes another welded portion different from the welded portion formed of a plurality of lines parallel to the longitudinal direction of the first busbar structure in a plan view.

10. The busbar laminate according to claim 1, wherein the branched portion includes a portion of the welded portion, and the branched portion includes a welded portion formed of a plurality of lines in a direction different from the longitudinal direction of the first busbar structure.

11. The busbar laminate according to claim 1, wherein the branch portion includes a part of the weld portion, and the branch portion includes a weld portion formed, in a plan view, by an enclosed line surrounded by two lines that face each other parallel to the longitudinal direction of the first busbar structure and two lines that face each other in a direction different from the longitudinal direction of the first busbar structure.

12. The busbar laminate according to claim 1 or 2, wherein the second busbar structure has the overlapping portion on only one side of the branch portion in the longitudinal direction of the first busbar structure.

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