Circuit branch structure

Abstract

To provide a circuit branch structure in which a previous predetermined design is not required, and which is improved in flexibility of a wiring path of a bus bar and capable of suppressing enlargement in dimension of a branch structure of the bus bar.SOLUTION: A circuit branch structure comprises: a first bus bar including first both end portions including one first terminal part and another first terminal part and a first main body portion which is a portion other than the first both end portions, and includes a first conducting part where an insulation part is formed in a first conductor and a first welding part where the insulation part is not formed in the first conductor; and a second bus bar including one second terminal part of a second conductor and a second main body portion including a second conducting part which is continued to the one second terminal part and where an insulation part is formed in the second conductor. The one second terminal part includes a second welding part where the insulation part is not formed, and the second welding part is connected with the first welding part so as to be conducted. The circuit branch structure has a connection in which the first bus bar and the second bus bar are in contact.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a circuit branch structure in which a bus bar used as a circuit member in a vehicle such as an automobile is branched. [Background technology]

[0002] Automobiles use many electrical components, such as electrically powered electrical devices and sensors that perform various controls, etc. These electrical components are connected to the battery, which serves as the power supply source, via various electric wires such as power lines and signal lines.

[0003] A battery pack containing a battery contains an element for protecting the upstream circuit to supply a large current, and an electrical junction box with a circuit control and circuit branching structure. For example, a bus bar, which is a plate-shaped conductor with a rectangular cross section, is sometimes used as a wiring body in a large current circuit such as a battery pack.

[0004] On the other hand, since the exterior of the electrical junction box is surrounded by many metal parts, the surface of the bus bar is insulated with an epoxy insulating powder coating, a protector, etc. to prevent short circuits, and the surface of the bus bar is covered with an insulating part.

[0005] Busbars are generally manufactured into a shape that conforms to the desired wiring path by pressing using a press die or by forming, which involves bending multiple times in a single process. However, because the component mounting positions and circuit specifications within the battery pack often differ depending on the vehicle model and equipment, i.e., the wiring path of the busbar often differs, it can be difficult to repurpose a busbar formed into a desired shape for a different vehicle model or equipment.

[0006] When manufacturing busbars compatible with different vehicle models or different equipment using press processing, new dies must be created, resulting in higher manufacturing costs. Furthermore, when manufacturing busbars using forming, the forming process involves bending the material as it is extruded, making it difficult to create busbar branch points. This can sometimes make it difficult to accommodate different vehicle models or different equipment, resulting in problems with the flexibility of the busbar's wiring route.

[0007] In order to address this issue, a busbar connection structure has been proposed (Patent Document 1), in which vertical busbars extending vertically in a straight line at a predetermined pitch are arranged on one side of an insulating plate, and horizontal busbars extending horizontally in a straight line at a predetermined pitch are arranged on the other side of the insulating plate, and through holes are formed in the insulating plate at the intersections of the busbars on both sides, and a recess that fits into the through hole is formed in at least one of the busbars on both sides at an appropriate location of the intersections, and this recess is brought into contact with and welded to a busbar on the opposite side, thereby electrically connecting the busbars on both sides (Patent Document 1).In Patent Document 1, the busbars are arranged by combining common straight vertical busbars and horizontal busbars, and the recesses at the intersections that connect the busbars on the upper and lower layers are simply welded, which eliminates the need to punch the busbars into different wiring path shapes using a dedicated press die, thereby reducing manufacturing costs.

[0008] However, in Patent Document 1, in order to achieve a desired connection structure, it is necessary to design the insulating plate, vertical bus bars, and horizontal bus bars in advance, and there is a need to improve the flexibility of the bus bar wiring path.In addition, in Patent Document 1, the vertical bus bars and horizontal bus bars are combined and arranged on the insulating plate, which causes a problem of large dimensions in the connection structure.

[0009] Another proposal is to provide an X-direction busbar layer in which rectangular busbars are arranged in parallel with a gap in the X direction and a Y-direction busbar layer in which rectangular busbars are arranged in parallel with a gap in the Y direction, to form a block by stacking the X-direction busbar layer and the Y-direction busbar layer, to provide a plurality of such blocks and stack them with insulating plates between them, and to electrically connect the intersections of the X-direction busbars and the Y-direction busbars at required positions in each block to form a branch circuit (Patent Document 2). Patent Document 2 claims that by using only rectangular busbars, it is possible to standardize the material and eliminate the need for punching using a die that was previously used to form the busbars.

[0010] However, in Patent Document 2, multiple sets of blocks each made of stacked X-direction busbar layers and Y-direction busbar layers are provided and stacked with insulating plates between them, which causes a problem of large dimensions for the busbar branch structure. Also, in Patent Document 2, all busbars are strip-shaped, so there was a need to improve the flexibility of the busbar wiring paths. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-177952 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-045633 Summary of the Invention [Problem to be solved by the invention]

[0012] In view of the above circumstances, an object of the present invention is to provide a circuit branching structure that does not require a predetermined design in advance, has excellent flexibility in the wiring path of the bus bar, and can prevent the dimensions of the bus bar branching structure from becoming large. [Means for solving the problem]

[0013] The gist of the configuration of the present invention is as follows. [1] A first bus bar including: first end portions having a first one end portion and a first other end portion; and a first main body portion, which is a portion other than the first end portions, having a first conductive portion in which an insulating portion is formed in a first conductor and a first welded portion in which the insulating portion is not formed in the first conductor; a second bus bar including: a second terminal portion of a second conductor; and a second body portion having a second conductive portion continuous with the second terminal portion, the second conductor having an insulating portion formed thereon; the second one terminal portion has a second welded portion where no insulating portion is formed, a circuit branch structure, the second welded portion being electrically conductively connected to the first welded portion, and having a connection portion where the first bus bar and the second bus bar are in contact. [2] The circuit branch structure according to [1], wherein the first main body portion has a longitudinal direction and a lateral direction, and the first welded portion is provided in a partial area in the lateral direction. [3] The circuit branch structure according to [1] or [2], wherein the second welded portion has an area equal to or greater than the cross-sectional area of the second conductor in the short direction. [4] The circuit branch structure described in [1] or [2], wherein the second one terminal portion is the second welded portion, and the first welded portion has a shape and area corresponding to the second one terminal portion. [5] The second one of the terminal portions has a terminal insulating portion in which an insulating portion is formed and the second welded portion, The circuit branch structure according to [1] or [2], wherein the connection portion has a portion where the second welded portion is electrically connected to the first welded portion, and a portion where the insulating portion of the first conductor and the terminal insulating portion are in contact with each other in the thickness direction of the insulating portion of the first conductor and the terminal insulating portion. [6] The circuit branch structure according to [5], further comprising a conductor member between the first welded portion and the second welded portion. [7] The circuit branch structure described in [5], wherein the first main body portion has a surface portion on the second bus bar side and a back surface portion facing the surface portion, and the first welded portion has a convex portion on the surface portion that protrudes toward the second welded portion and a concave portion on the back surface portion that is recessed toward the second welded portion. [8] The circuit branch structure described in [5], wherein the second one of the terminal portions has a back surface portion on the first bus bar side and a front surface portion facing the back surface portion, and the second welded portion has a convex portion on the back surface portion that protrudes toward the first welded portion and a concave portion on the front surface portion that is recessed toward the first welded portion. [9] The circuit branching structure according to [1] or [2], wherein the first one terminal portion is connected to an electrical connection box and the first other terminal portion is connected to an external output terminal.

[10] A first bus bar including: first end portions having a first one end portion and a first other end portion; and a first main body portion that is a portion other than the first end portions and has a first conductive portion in which an insulating portion is formed in a first conductor and a first welded portion in which the insulating portion is not formed in the first conductor; a second bus bar including: a second terminal portion of a second conductor; and a second body portion having a second conductive portion continuous with the second terminal portion, the second conductor having an insulating portion formed thereon; the second one terminal portion has a second welded portion where no insulating portion is formed, the second welded portion is electrically conductively connected to the first welded portion, and the battery pack has a connection portion where the first bus bar and the second bus bar are in contact with each other, the first one terminal portion of the first bus bar is connected to an electric junction box, and the first other terminal portion of the first bus bar is connected to an external output terminal; The second one terminal portion of the second bus bar is connected to the connection portion, and the other terminal portion of the second bus bar is connected to another external output terminal.

[11] The battery pack according to

[10] , wherein an additional electrical junction box is further connected to the second body portion of the second bus bar.

[12] The battery pack according to

[10] , wherein a charging electrical connection box is further connected to the second body portion of the second bus bar. [Effects of the Invention]

[0014] According to the circuit branch structure of the present invention, there is provided a first busbar having first end portions having a first one end portion and a first other end portion, and a first main body portion at a location other than the first end portions, the first main body portion having a first conductive portion where an insulating portion is formed in the first conductor and a first welded portion where the insulating portion is not formed in the first conductor, and a second busbar having a second one end portion of a second conductor and a second conductive portion continuous with the second one end portion, the second one end portion having a second welded portion where an insulating portion is formed in the second conductor, the second welded portion being electrically conductively connected to the first welded portion, and a connection portion where the first busbar and the second busbar are in contact. This eliminates the need for a predetermined design, provides excellent flexibility in the wiring path of the busbar, and prevents the busbar branch structure from becoming large in size.

[0015] According to the circuit branch structure of the present invention, the first welded portion and the second welded portion have an area equal to or greater than the cross-sectional area of the second conductor in the short direction, thereby making it possible to obtain a branching portion of the first bus bar and the second bus bar that can accommodate the current value passed through the second bus bar.

[0016] According to the circuit branch structure of the present invention, the second one terminal portion is made of the second welded portion, and the first welded portion has a shape and area corresponding to the second one terminal portion, so that the insulating portion of the first conductor that forms the periphery of the first welded portion functions as a positioning portion for the second welded portion, thereby improving the connection accuracy of the first welded portion and the second welded portion.

[0017] According to the circuit branch structure of the present invention, the second one of the terminal portions has a terminal insulating portion in which an insulating portion is formed and the second welded portion, and the connection portion has a portion where the second welded portion is electrically connected to the first welded portion, and a portion where the insulating portion of the first conductor and the terminal insulating portion are in contact with each other in the thickness direction of the terminal insulating portion, and by having a further conductive member between the first welded portion and the second welded portion, the connection reliability of the first welded portion and the second welded portion is improved.

[0018] According to the circuit branch structure of the present invention, the second one of the terminal portions has a terminal insulation portion on which an insulating portion is formed and the second weld portion, the connection portion has a portion where the second weld portion is electrically conductively connected to the first weld portion and a portion where the insulation portion of the first conductor and the terminal insulation portion contact each other in the thickness direction of the terminal insulation portion, the first main body portion has a surface portion on the second bus bar side and a back surface portion facing the surface portion, and the first weld portion has a convex portion on the surface portion that protrudes toward the second weld portion and a concave portion on the back surface that is recessed toward the second weld portion, thereby improving the connection reliability of the first weld portion and the second weld portion.

[0019] According to the circuit branch structure of the present invention, the second one of the terminal portions has a terminal insulation portion on which an insulating portion is formed and the second welded portion, the connection portion has a portion where the second welded portion is electrically conductively connected to the first welded portion and a portion where the insulation portion of the first conductor and the terminal insulation portion contact each other in the thickness direction of the terminal insulation portion, the second one of the terminal portions has a back surface portion on the first bus bar side and a front surface portion facing the back surface portion, and the second welded portion has a convex portion on the back surface portion that protrudes toward the first welded portion and a concave portion on the front surface portion that is recessed toward the first welded portion, thereby improving the connection reliability of the first welded portion and the second welded portion. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a side cross-sectional view of a circuit branch structure according to a first embodiment of the present invention. [Figure 2] FIG. 2 is an explanatory view showing a state after an insulating portion removing step in the manufacturing process of the circuit branch structure according to the first embodiment of the present invention. [Figure 3] 3 is an explanatory diagram of a circuit branch structure obtained after a welding step in the manufacturing process of the circuit branch structure according to the first embodiment of the present invention. FIG. [Figure 4] FIG. 10 is a side cross-sectional view of a circuit branch structure according to a second embodiment of the present invention. [Figure 5] FIG. 10 is a side cross-sectional view of a circuit branch structure according to a third embodiment of the present invention. [Figure 6] FIG. 10 is a side cross-sectional view of a circuit branch structure according to a fourth embodiment of the present invention. [Figure 7] FIG. 10 is a side cross-sectional view of a circuit branch structure according to a fifth embodiment of the present invention. [Figure 8] 1 is an explanatory diagram of a first example of a method of using the circuit branch structure of the present invention. [Figure 9] 10 is an explanatory diagram of a second example of a method of using the circuit branch structure of the present invention. FIG. [Figure 10] 10A and 10B are explanatory diagrams illustrating a third example of a method of using the circuit branch structure of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] A circuit branch structure according to a first embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is a side cross-sectional view of the circuit branch structure according to the first embodiment of the present invention. Fig. 2 is an explanatory diagram of the circuit branch structure according to the first embodiment of the present invention after the insulation removal step in the manufacturing process. Fig. 3 is an explanatory diagram of the circuit branch structure obtained after the welding step in the manufacturing process of the circuit branch structure according to the first embodiment of the present invention.

[0022] As shown in Figures 1 and 3, the circuit branch structure 1 according to the first embodiment includes a first bus bar 10 and a second bus bar 20, and is a circuit branch structure in which the second bus bar 20 branches off from the first bus bar 10.

[0023] The first busbar 10 of the circuit branch structure 1 has first end portions 18 having a first one terminal portion 17 and a first other terminal portion (not shown), and a first main body portion 11 which is a portion other than the first end portions 18 and has a first conductive portion 13 where an insulating portion 15 is formed in the first conductor 14 and a first welded portion 12 where the insulating portion 15 is not formed in the first conductor 14. In the first main body portion 11 which is the main body portion of the first busbar 10, the first welded portion 12 where the insulating portion 15 is not formed is a portion where the first conductor 14 which is the conductor of the first busbar 10 is exposed. In addition, in the first main body portion 11, the first conductive portion 13 which is the conductive portion of the first busbar 10 and where the insulating portion 15 is formed is a portion where the first conductor 14 is not exposed.

[0024] The insulating portion 15 may be, for example, an insulating coating that covers the surface of the first conductor 14. Examples of the insulating coating include insulating powder coating made of epoxy or nylon resin, a resin protector, and insulating tape.

[0025] The second busbar 20 of the circuit branch structure 1 has a second one terminal portion 27 of the second conductor 24 and a second body portion 21 that is continuous with the second one terminal portion 27 and has a second conductive portion 23 in which an insulating portion 25 is formed on the second conductor 24, and the second one terminal portion 27 has a second weld portion 22 in which the insulating portion 25 is not formed. In the second busbar 20, the second body portion 21, which is the main portion of the second busbar 20, has the insulating portion 25 formed therein and constitutes the second conductive portion 23, which is the conductive portion of the second busbar 20. The second body portion 21 is a portion where the second conductor 24, which is the conductor of the second busbar 20, is not exposed. In addition, the second weld portion 22, which is formed at the second one terminal portion 27 and in which the insulating portion 25 is not formed, is a portion where the second conductor 24 is exposed.

[0026] An example of the insulating portion 25 is an insulating coating that covers the surface of the second conductor 24. Examples of the insulating coating include insulating powder coating made of epoxy or nylon resin, a resin protector, and insulating tape.

[0027] In the circuit branch structure 1, the second welded portion 22 of the second bus bar 20 is electrically conductively connected to the first welded portion 12 of the first bus bar 10. The overlapping portion where the first welded portion 12 of the first bus bar 10 and the second welded portion 22 of the second bus bar 20 are overlapped is welded, so that the second welded portion 22 of the second bus bar 20 is electrically conductively connected to the first welded portion 12 of the first bus bar 10.

[0028] As described above, the circuit branch structure 1 has a connection portion 30 where the first bus bar 10 and the second bus bar 20 are in contact, and at the connection portion 30, the second welded portion 22 of the second bus bar 20 and the first welded portion 12 of the first bus bar 10 are electrically connected.

[0029] The connection portion 30 is a circuit branch portion where the second bus bar 20 branches off from the first bus bar 10. In the circuit branch structure 1, the second body portion 21 of the second bus bar 20 extends in a direction substantially perpendicular to the extension direction of the first body portion 11 of the first bus bar 10 at the circuit branch portion (i.e., the connection portion 30). The extension direction of the second bus bar 20 can be set to any direction relative to the extension direction of the first body portion 11 of the first bus bar 10.

[0030] Furthermore, since the second one terminal portion 27 of the second busbar 20 has the second welded portion 22, the second main body portion 21 of the second busbar 20 extends in one direction relative to the extension direction of the first main body portion 11 of the first busbar 10 at the circuit branch portion (i.e., the connection portion 30).

[0031] 3, the first body portion 11 of the first busbar 10 has a longitudinal direction that forms the wiring path of the first busbar 10 and a lateral direction that is the width direction of the first busbar 10. A first welded portion 12 is provided in a partial region in the lateral direction of the first body portion 11 of the first busbar 10. That is, the portion of the first body portion 11 where the first welded portion 12 is provided has, in the lateral direction of the first body portion 11, a coated portion 16 where the insulating portion 15 is formed and a portion where the insulating portion 15 is not formed (i.e., the first welded portion 12).

[0032] As described above, in the circuit branching structure 1, the coated portion 16 of the first body portion 11 does not form the connection portion 30. In the short direction of the first body portion 11 at the portion where the connection portion 30 is provided, the connection portion 30 forms a partial region of the first body portion 11.

[0033] In the circuit branch structure 1, the second one terminal portion 27 is made up of the second welded portion 22. That is, the entire area of the second one terminal portion 27 is made up of the second welded portion 22, and the entire area of the second one terminal portion 27 of the second bus bar 20 in the short direction is made up of the second welded portion 22.

[0034] In the circuit branch structure 1, the first welded portion 12 has a shape and area corresponding to the second one of the terminal portions 27. As described above, the second one of the terminal portions 27 of the second bus bar 20 has a shape and area corresponding to the first welded portion 12, and the second one of the terminal portions 27 is configured to be able to fit into the first welded portion 12. Specifically, as shown in FIG. 2 , the first welded portion 12 is formed on the side of the first bus bar 10 in the short direction, which is the width direction of the first bus bar 10, where the second bus bar 20 is connected, and the coated portion 16, which is the insulating portion 15, is formed on the side where the second bus bar 20 is not connected. Therefore, when joining the second bus bar 20, the second bus bar 20 can be easily positioned in the longitudinal direction by abutting the second bus bar 20 against the step formed by the insulating portion 15. 1, the dimension of first welded portion 12 in the longitudinal direction of first bus bar 10 is formed to match the dimension in the lateral direction, which is the width direction, of second bus bar 20. Therefore, when joining second bus bar 20, fitting second bus bar 20 between the steps formed by insulating portions 15 makes it easy to position second bus bar 20 in the width direction.

[0035] Second welded portion 22 has an area equal to or larger than the cross-sectional area in the short direction of second conductor 24. Therefore, in circuit branch structure 1, connection portion 30, which is the branch portion of first bus bar 10 and second bus bar 20, can be obtained, which is capable of handling the value of the current passed through second bus bar 20.

[0036] Next, a manufacturing method of the circuit branch structure 1 according to the first embodiment will be described. As shown in FIG. 2 , first, a first bus bar 10 having an insulating portion 15 formed on a first conductor 14 and a second bus bar 20 having an insulating portion 25 formed on a second conductor 24 are prepared. Next, a laser is irradiated onto a portion of the first main body portion 11 of the first bus bar 10 corresponding to the first weld portion 12, thereby removing the insulating portion 15 at the portion corresponding to the first weld portion 12 and exposing the first conductor 14. By exposing the first conductor 14, the first weld portion 12 is formed. Furthermore, a laser is irradiated onto a second one terminal portion 27 of the second bus bar 20, thereby removing the insulating portion 25 of the second one terminal portion 27 and exposing the second conductor 24. The insulating portion 25 is removed from both the surface contacting the first bus bar 10 and the surface opposite to the surface contacting the first bus bar 10. By exposing the second conductor 24, the second weld portion 22 is formed. In the second welding portion 22, if the surface exposed by removing the insulating portion 25 on the surface opposite to the surface in contact with the first bus bar 10 is approximately the area required for welding, the exposed area of the second conductor 24 can be minimized, thereby preventing deterioration of insulation properties.

[0037] Next, as shown in FIG. 3 , the second weld portion 22 is overlapped on the first weld portion 12 from a direction substantially perpendicular to the elongation direction of the first main body portion 11 of the first bus bar 10. When the second weld portion 22 is overlapped on the first weld portion 12, the second weld portion 22 is in direct contact with the first weld portion 12. Next, the overlapping portion where the second weld portion 22 is overlapped on the first weld portion 12 is welded to electrically connect the second weld portion 22 to the first weld portion 12, thereby forming a connection portion 30 where the first bus bar 10 and the second bus bar 20 are in contact. Methods for welding the overlapping portion include laser welding, resistance welding, ultrasonic welding, gas welding, arc welding, and friction welding. Of these welding methods, laser welding is preferred because it allows localized heating and enables joining in a short time. The shape of the laser weld can be appropriately formed to match the shape of the weld portion. For example, a laser may be scanned along the outer shape of the weld to form a line, or a laser may be scanned over any surface of the weld to form a planar shape, or a point may be formed in a part of the weld. Circuit branch structure 1 can be manufactured by forming connection portion 30 where first bus bar 10 and second bus bar 20 are in contact.

[0038] After manufacturing the circuit branch structure 1, if necessary, the connection portion 30 may be protected and insulated by applying a protector, tape (insulating tape and heat-resistant tape), etc., or by potting.

[0039] The circuit branch structure 1 comprises a first busbar 10 having a first main body portion 11 having a first conductive portion 13 in which an insulating portion 15 is formed on a first conductor 14 and a first welded portion 12 in which no insulating portion 15 is formed on the first conductor 14, and a second busbar 20 having a second welded portion 22 in which no insulating portion 25 is formed on a second one of the terminal portions 27, wherein the second welded portion 22 is conductively connected to the first welded portion 12 and has a connection portion 30 where the first busbar 10 and the second busbar 20 are in contact. Therefore, there is no need for a predetermined design for the first busbar 10 and the second busbar 20, excellent flexibility in the wiring paths of the first busbar 10 and the second busbar 20, and the branch structure for the first busbar 10 and the second busbar 20 can be prevented from becoming large in size.

[0040] Furthermore, in the circuit branch structure 1, the second one terminal portion 27 consists of the second welded portion 22, and the first welded portion 12 has a shape and area corresponding to the second one terminal portion 27, so that the insulating portion 15 of the first conductor 14 that forms the periphery of the first welded portion 12 functions as a positioning portion for the second welded portion 22, thereby improving the connection accuracy between the first welded portion 12 and the second welded portion 22.

[0041] Next, a circuit branch structure according to a second embodiment of the present invention will be described with reference to the drawings. The circuit branch structure according to the second embodiment shares major components with the circuit branch structure according to the first embodiment, and therefore the same components as those in the circuit branch structure according to the first embodiment will be described using the same reference numerals. Note that Fig. 4 is a side cross-sectional view of the circuit branch structure according to the second embodiment of the present invention.

[0042] In the circuit branch structure 1 of the first embodiment, the second one terminal portion 27 consists of the second welded portion 22, and the first welded portion 12 has a shape and area corresponding to the second one terminal portion 27. However, as shown in FIG. 4, in the circuit branch structure 2 of the second embodiment, the second one terminal portion 27 has a terminal insulating portion 26 in which the insulating portion 25 is formed and a second welded portion 22 in which the second conductor 24 is exposed, and the connection portion 30 has a portion where the second welded portion 22 is electrically conductively connected to the first welded portion 12, and a portion where the insulating portion 15 of the first conductor 14 and the terminal insulating portion 26 are in contact with each other in the thickness direction of the terminal insulating portion 26.

[0043] In the circuit branch structure 2 as well, the second welded portion 22 has an area equal to or larger than the cross-sectional area of the second conductor 24 in the short-side direction.

[0044] In the circuit branch structure 2, before welding, the overlapping portion where the second welded portion 22 overlaps the first welded portion 12 is not in contact with the second welded portion 22. When welding is performed on the overlapping portion where the second welded portion 22 overlaps the first welded portion 12, the second conductor 24 of the second welded portion melts and blends into the first welded portion, and the first welded portion 12 and the second welded portion 22 are welded together, and the second welded portion 22 is electrically connected to the first welded portion 12.

[0045] Circuit branch structure 2 also includes first busbar 10 having first main body portion 11 having first conductive portion 13 where first conductor 14 has insulating portion 15 formed thereon and first welded portion 12 where first conductor 14 does not have insulating portion 15 formed thereon, and second busbar 20 having second welded portion 22 where second one terminal portion 27 has no insulating portion 25 formed thereon, and second welded portion 22 is electrically conductively connected to first welded portion 12, and first busbar 10 and second busbar 20 have connection portion 30 where they come into contact. This eliminates the need for a predetermined design for first busbar 10 and second busbar 20, provides excellent flexibility in the wiring paths of first busbar 10 and second busbar 20, and prevents the branch structure for first busbar 10 and second busbar 20 from becoming large in size. Furthermore, circuit branch structure 2 does not require a larger welded portion (portion where insulating portion is removed) than circuit branch structure 1, and therefore has better insulation properties.

[0046] Next, a circuit branch structure according to a third embodiment of the present invention will be described with reference to the drawings. The circuit branch structure according to the third embodiment shares major components with the circuit branch structures according to the first and second embodiments, and therefore the same components as those in the circuit branch structures according to the first and second embodiments will be described using the same reference numerals. Note that Fig. 5 is a side cross-sectional view of the circuit branch structure according to the third embodiment of the present invention.

[0047] In the circuit branch structure 2 of the second embodiment, the second one of the terminal portions 27 has a terminal insulating portion 26 where the insulating portion 25 is formed and a second welded portion 22 where the second conductor 24 is exposed, and the connection portion 30 has a portion where the second welded portion 22 is conductively connected to the first welded portion 12, and a portion where the insulating portion 15 of the first conductor 14 and the terminal insulating portion 26 are in contact with each other in the thickness direction of the insulating portion 15 of the first conductor 14 and the terminal insulating portion 26. However, as shown in Figure 5, the circuit branch structure 3 of the third embodiment further has a conductor member 31 between the first welded portion 12 and the second welded portion 22.

[0048] The conductor member 31 has a thickness corresponding to the sum of the thickness of the insulating portion 15 and the thickness of the insulating portion 25. The conductor member 31 has a shape and area that allows it to come into contact with the first welding portion 12, and also has a shape and area that allows it to come into contact with the second welding portion 22. The conductor member 31 may be made of the same material as the first conductor 14 and the second conductor 24.

[0049] In the circuit branch structure 3, before welding, the overlapping portion where the second welded portion 22 is overlapped on the first welded portion 12 is not in a state where the first welded portion 12 and the second welded portion 22 are in a state where they are in contact with each other, but rather in a state where the first welded portion 12 and the second welded portion 22 are opposed to each other via the conductor member 31. When welding is performed on the overlapping portion where the first welded portion 12 and the second welded portion 22 are opposed to each other via the conductor member 31, the first welded portion 12 and the second welded portion 22 are fused to each other via the conductor member 31, and the second welded portion 22 is electrically connected to the first welded portion 12.

[0050] The circuit branch structure 3 also comprises a first busbar 10 having a first main body portion 11 having a first conductive portion 13 in which an insulating portion 15 is formed on a first conductor 14 and a first welded portion 12 in which no insulating portion 15 is formed on the first conductor 14, and a second busbar 20 having a second welded portion 22 in which no insulating portion 25 is formed on a second one of the terminal portions 27, and the second welded portion 22 is conductively connected to the first welded portion 12 and has a connection portion 30 where the first busbar 10 and the second busbar 20 are in contact.Therefore, there is no need for a predetermined design for the first busbar 10 and the second busbar 20, and the wiring paths of the first busbar 10 and the second busbar 20 are highly flexible, and the dimensions of the branch structure of the first busbar 10 and the second busbar 20 can be prevented from becoming large.

[0051] Furthermore, in the circuit branch structure 3, by further having a conductor member 31 between the first welded portion 12 and the second welded portion 22, and by having a conductor member with an area approximately the same as that of the first welded portion and the second welded portion (exposed conductor area), the positional accuracy of the two welded portions relative to each other is increased, and the connection reliability of the first welded portion 12 and the second welded portion 22 is improved.

[0052] Next, a circuit branch structure according to a fourth embodiment of the present invention will be described with reference to the drawings. The circuit branch structure according to the fourth embodiment shares major components with the circuit branch structures according to the first to third embodiments, and therefore the same components as those in the circuit branch structures according to the first to third embodiments will be described using the same reference numerals. Note that Fig. 6 is a side cross-sectional view of the circuit branch structure according to the fourth embodiment of the present invention.

[0053] In the circuit branch structure 2 according to the second embodiment, the connection portion 30 has a portion where the insulating portion 15 of the first conductor 14 and the terminal insulating portion 26 are in contact with each other in the thickness direction of the insulating portion 15 of the first conductor 14 and the terminal insulating portion 26, and before welding, the first welded portion 12 and the second welded portion 22 were not in contact with each other at the overlapping portion where the second welded portion 22 was overlapped with the first welded portion 12. Instead, as shown in Fig. 6, in the circuit branch structure 4 according to the fourth embodiment, the first main body portion 11 has a surface portion 43 on the second bus bar 20 side and a back surface portion 44 facing the surface portion 43, and the first welded portion 12 has a convex portion 41 on the surface portion 43 that protrudes toward the second welded portion 22 and a concave portion 42 on the back surface portion 44 that is recessed toward the second welded portion 22.

[0054] In the circuit branch structure 4, the connection portion 30 has a portion where the insulating portion 15 of the first conductor 14 and the terminal insulating portion 26 are in contact with each other in the thickness direction of the insulating portion 15 of the first conductor 14 and the terminal insulating portion 26, but before welding, the overlapping portion where the second welding portion 22 is overlapped on the first welding portion 12 is in a state where the convex portion 41 of the first welding portion 12 is in contact with the second welding portion 22.

[0055] The convex portion 41 and the concave portion 42 of the first welded portion 12 can be formed, for example, by pressing the first main body portion 11 from the rear surface portion 44 side.

[0056] The circuit branch structure 4 also comprises a first busbar 10 having a first main body portion 11 having a first conductive portion 13 in which an insulating portion 15 is formed on the first conductor 14 and a first welded portion 12 in which no insulating portion 15 is formed on the first conductor 14, and a second busbar 20 having a second welded portion 22 in which no insulating portion 25 is formed on a second one of the terminal portions 27, and the second welded portion 22 is conductively connected to the first welded portion 12 and has a connection portion 30 where the first busbar 10 and the second busbar 20 are in contact.Therefore, there is no need for a predetermined design for the first busbar 10 and the second busbar 20, and the wiring paths of the first busbar 10 and the second busbar 20 are highly flexible, and the dimensions of the branch structure of the first busbar 10 and the second busbar 20 can be prevented from becoming large.

[0057] Furthermore, in the circuit branch structure 4, the first welded portion 12 has a convex portion 41 on the surface portion 43 that protrudes toward the second welded portion 22. By having the convex portion 41 on the surface portion 43 with an area approximately the same as that of the first welded portion and the second welded portion (exposed conductor range), the positional accuracy of the two welded portions relative to each other is increased, and the connection reliability between the first welded portion 12 and the second welded portion 22 is improved.

[0058] Next, a circuit branch structure according to a fifth embodiment of the present invention will be described with reference to the drawings. The circuit branch structure according to the fifth embodiment shares major components with the circuit branch structures according to the first to fourth embodiments, and therefore the same components as those in the circuit branch structures according to the first to fourth embodiments will be described using the same reference numerals. Note that Fig. 7 is a side cross-sectional view of the circuit branch structure according to the fifth embodiment of the present invention.

[0059] In the circuit branch structure 2 according to the second embodiment, the connection portion 30 has a portion where the insulating portion 15 of the first conductor 14 and the terminal insulating portion 26 are in contact with each other in the thickness direction of the insulating portion 15 of the first conductor 14 and the terminal insulating portion 26, and before welding, the first welded portion 12 and the second welded portion 22 were not in contact with each other at the overlapping portion where the second welded portion 22 was overlapped with the first welded portion 12. Instead, as shown in Fig. 7 , in the circuit branch structure 5 according to the fifth embodiment, the second one of the terminal portions 27 has a back surface portion 54 on the first bus bar 10 side and a front surface portion 53 facing the back surface portion 54, and the second welded portion 22 has a convex portion 51 on the back surface portion 54 that protrudes toward the first welded portion 12 and a concave portion 52 on the front surface portion 53 that is recessed toward the first welded portion 12.

[0060] In the circuit branch structure 5, the connection portion 30 has a portion where the insulating portion 15 of the first conductor 14 and the terminal insulating portion 26 are in contact with each other in the thickness direction of the insulating portion 15 of the first conductor 14 and the terminal insulating portion 26, but before welding, the overlapping portion where the second welding portion 22 is overlapped on the first welding portion 12 is in a state where the convex portion 51 of the second welding portion 22 is in contact with the first welding portion 12.

[0061] The convex portion 51 and the concave portion 52 of the second welded portion 22 can be formed, for example, by pressing from the surface portion 53 side of the second one terminal portion 27.

[0062] The circuit branch structure 5 also comprises a first busbar 10 having a first main body portion 11 having a first conductive portion 13 in which an insulating portion 15 is formed on the first conductor 14 and a first welded portion 12 in which no insulating portion 15 is formed on the first conductor 14, and a second busbar 20 having a second welded portion 22 in which no insulating portion 25 is formed on a second one of the terminal portions 27, and the second welded portion 22 is conductively connected to the first welded portion 12 and has a connection portion 30 where the first busbar 10 and the second busbar 20 are in contact.Therefore, there is no need for a predetermined design for the first busbar 10 and the second busbar 20, and the wiring paths of the first busbar 10 and the second busbar 20 are highly flexible, and the dimensions of the branch structure of the first busbar 10 and the second busbar 20 can be prevented from becoming large.

[0063] Furthermore, in the circuit branch structure 5, the second welded portion 22 has a convex portion 51 on the back surface 54 that protrudes toward the first welded portion 12. By having the convex portion 51 on the back surface 54 with an area approximately the same as that of the first welded portion and the second welded portion (exposed conductor range), the positional accuracy of the two welded portions relative to each other is improved, and the connection reliability between the first welded portion 12 and the second welded portion 22 is improved.

[0064] Next, an example of how to use the circuit branch structure of the present invention will be described. Here, an example where the circuit branch structure of the present invention is used in a battery pack will be described. FIG. 8 is an explanatory diagram of a first example of how to use the circuit branch structure of the present invention. FIG. 9 is an explanatory diagram of a second example of how to use the circuit branch structure of the present invention. FIG. 10 is an explanatory diagram of a third example of how to use the circuit branch structure of the present invention. For ease of explanation, the circuit branch structure of the present invention will be described using the circuit branch structure 1 according to the first embodiment.

[0065] First, a first example of how to use the circuit branch structure of the present invention will be described. As shown in Fig. 8, in the circuit branch structure 1, the first bus bar 10 forms a main circuit, and the second bus bar 20 forms a branch circuit branching off from the main circuit.

[0066] 8, in the first usage example, first one terminal portion 17, which is one terminal portion of first bus bar 10, is connected to electric junction box 100 which is connected to battery 101, and first other terminal portion 19, which is the other terminal portion of first bus bar 10, is connected to external output terminal 102. External output terminal 102 is, for example, a connector, and is connected to vehicle accessories such as a main motor and an inverter via the connector.

[0067] One end of second busbar 20, that is, second one end 27, is connected to connection portion 30 with first busbar 10 of circuit branch structure 1, and the other end of second busbar 20, that is, second other end 29, is connected to external output terminal 103. External output terminal 103 is, for example, a connector, and is connected to vehicle accessories such as a sub-motor and additional equipment via the connector.

[0068] Next, a second example of how to use the circuit branching structure of the present invention will be described. The second example of how to use the circuit branching structure of the present invention shares major components with the first example of how to use the circuit branching structure, and therefore the same components as in the first example of how to use the circuit branching structure will be described using the same reference numerals.

[0069] 9 , in the second usage example, an additional electric junction box 104 is connected to the second main body 21 of the second bus bar 20 of the first usage example. The electric junction box 100 connected to the battery 101 is an electric junction box having basic functions, whereas the additional electric junction box 104 is an electric junction box having functions associated with vehicle-specific equipment provided for each vehicle or additional equipment due to a minor change, etc. In the second usage example as well, the second other terminal 29, which is the other terminal of the second bus bar 20, is connected to the external output terminal 103.

[0070] Next, a third example of a method of using the circuit branching structure of the present invention will be described. The third example of a method of using the circuit branching structure of the present invention shares major components with the first and second examples of use, and therefore the same components as those in the first and second examples of use will be described using the same reference numerals.

[0071] In the second usage example, the second other terminal portion 29 of the second bus bar 20 is connected to the external output terminal 103, and an additional electrical junction box 104 is further connected to the second main body portion 21 of the second bus bar 20. However, instead, as shown in FIG. 10 , in the third usage example, the second other terminal portion 29 of the second bus bar 20 is connected to the external output terminal 105. In the third usage example, the external output terminal 105 is, for example, a connector, and is connected to the on-board charger charging mechanism of the charging stand via the connector. In addition, in the third usage example, a charging electrical junction box 106 is connected to the second main body portion 21 of the second bus bar 20.

[0072] Charging standards for electric vehicles and the like change constantly, and in the third example of the use of the circuit branch structure of the present invention, the charging circuit can be easily changed to accommodate changes in charging standards. [Explanation of symbols]

[0073] 1, 2, 3, 4, 5 circuit branch structure 10 First bus bar 12 First Welding Section 20 Second bus bar 22 Second Welding Section 30 Connection

Claims

1. a first bus bar including: first end portions each having a first one end portion and a first other end portion; and a first main body portion that is a portion other than the first end portions and that has a first conductive portion in which an insulating portion is formed in a first conductor and a first welded portion in which the insulating portion is not formed in the first conductor; a second bus bar including: a second one terminal portion of a second conductor; and a second body portion having a second conductive portion continuous with the second one terminal portion, the second conductor having an insulating portion formed thereon; the second one of the terminal portions has a second welded portion where no insulating portion is formed, a circuit branch structure, the second welded portion being electrically conductively connected to the first welded portion, and having a connection portion where the first bus bar and the second bus bar are in contact.

2. The circuit branch structure according to claim 1 , wherein the first main body portion has a longitudinal direction and a lateral direction, and the first welded portion is provided in a partial area in the lateral direction.

3. The circuit branch structure according to claim 1 or 2, wherein the second welded portion has an area equal to or larger than a cross-sectional area of the second conductor in the short-side direction.

4. The circuit branch structure according to claim 1 or 2, wherein the second one terminal portion is formed by the second welded portion, and the first welded portion has a shape and area corresponding to the second one terminal portion.

5. the second one of the terminal portions has a terminal insulating portion in which an insulating portion is formed and the second weld portion, 3. The circuit branch structure according to claim 1, wherein the connection portion has a portion where the second welded portion is electrically connected to the first welded portion, and a portion where the insulating portion of the first conductor and the terminal insulating portion are in contact with each other in the thickness direction of the terminal insulating portion.

6. The circuit branch structure according to claim 5 , further comprising a conductive member between the first welded portion and the second welded portion.

7. 6. The circuit branch structure according to claim 5, wherein the first main body portion has a surface portion on the second bus bar side and a back surface portion facing the surface portion, and the first welded portion has a convex portion on the surface portion that protrudes toward the second welded portion and a concave portion on the back surface portion that is recessed toward the second welded portion.

8. 6. The circuit branch structure according to claim 5, wherein the second one terminal portion has a back surface portion on the first bus bar side and a front surface portion facing the back surface portion, and the second welded portion has a convex portion on the back surface portion that protrudes toward the first welded portion and a concave portion on the front surface portion that is recessed toward the first welded portion.

9. 3. The circuit branch structure according to claim 1, wherein the first one terminal portion is connected to an electric junction box, and the first other terminal portion is connected to an external output terminal.

10. a first bus bar including: first end portions each having a first one end portion and a first other end portion; and a first main body portion that is a portion other than the first end portions and that has a first conductive portion in which an insulating portion is formed in a first conductor and a first welded portion in which the insulating portion is not formed in the first conductor; a second bus bar including: a second one terminal portion of a second conductor; and a second body portion having a second conductive portion continuous with the second one terminal portion, the second conductor having an insulating portion formed thereon; the second one of the terminal portions has a second welded portion where no insulating portion is formed, the second welded portion is electrically conductively connected to the first welded portion, and the battery pack has a connection portion where the first bus bar and the second bus bar are in contact with each other, the first one terminal portion of the first bus bar is connected to an electric junction box, and the first other terminal portion of the first bus bar is connected to an external output terminal; the second one terminal portion of the second bus bar is connected to the connection portion, and the other terminal portion of the second bus bar is connected to another external output terminal.

11. The battery pack according to claim 10 , wherein an additional electrical junction box is further connected to the second body portion of the second bus bar.

12. The battery pack according to claim 10 , further comprising a charging electrical junction box connected to the second body portion of the second bus bar.

Images