Bus bar

Abstract

To provide a bus bar that suppresses peeling of a resin covering portion from a conductor by combining a flatwise-processed portion and twisted-processed portions at a bent portion.SOLUTION: A bus bar 4 comprises a conductor formed of a flat wire and an insulating resin covering portion covering the conductor, the bus bar 4 including a bent portion 12, the direction in which the bus bar 4 extends being an extending direction, wherein the bent portion 12 includes a flatwise-processed portion 21, a first twisted-processed portion 22 provided on one side in the extending direction of the flatwise-processed portion 21, and a second twisted-processed portion 23 provided on the other side.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a bus bar. [Background technology]

[0002] Busbars are used as wiring components that connect power sources to various components. Busbars are not limited to straight busbars; some have straight and curved sections depending on the layout of the installation location. For example, the busbar disclosed in Patent Document 1 uses rectangular wire as the conductor and is surrounded by an insulating resin coating to save space during wiring. The curved sections of such busbars are formed by edgewise processing, which bends the busbar in the plane direction of the rectangular wire. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-190933 Summary of the Invention [Problem to be solved by the invention]

[0004] In a busbar in which the conductor is covered with a resin coating, edgewise processing compresses the resin coating on the inner periphery of the bent portion, causing the resin coating to lift up from the conductor at the inner periphery of the bent portion, resulting in wrinkles and other defects.

[0005] To solve this problem, Patent Document 1 describes a method in which an opening is formed on one side of the resin-coated portion, and the opening is filled by bending the resin-coated portion so that the side with the opening faces inward.

[0006] However, the configuration of Patent Document 1 requires the provision of a comb-shaped opening on one side to form a gap. This increases the number of steps in the busbar manufacturing process, making it difficult to improve production efficiency. It also makes it impossible to pre-coat the conductor with resin. Furthermore, edgewise processing makes it difficult to fine-tune the position of the end of the busbar if it is misaligned from its intended mounting position. [Means for solving the problem]

[0007] A busbar for solving the above problem includes a conductor made of a flat wire and an insulating resin coating covering the conductor, wherein the busbar includes a bent portion, the direction in which the busbar extends is the extension direction, and the bent portion includes a flatwise processed portion and a first twist processed portion on one side of the flatwise processed portion in the extension direction, and a second twist processed portion on the other side.

[0008] According to the above configuration, by providing twisted sections on both sides of the flatwise processed section at the bent section, it is possible to prevent wrinkles and the like caused by the resin coating peeling off and lifting up from the conductor.

[0009] In the above-mentioned busbar, it is preferable that, in the extension direction, a first inner end of the first twist processed portion is located between a first end of the flatwise processed portion and a position that is 3.0 times the width of the busbar, and a second inner end of the second twist processed portion is located between a second end of the flatwise processed portion and a position that is 3.0 times the width of the busbar.

[0010] According to the above configuration, the bent portion can be formed by providing the first and second twisted portions near the flatwise processed portion. Furthermore, by positioning the first and second inner ends of the twisted portions at a distance up to 3.0 times the width of the busbar, the proportion of the bent portion to the overall length of the busbar can be prevented from becoming too large.

[0011] In the busbar, it is preferable that, in the extension direction, a first twist distance between a first inner end and a first outer end in the first twist processed portion, and a second twist distance between a second inner end and a second outer end in the second twist processed portion are 1.0 times or more and 3.0 times or less the width of the busbar.

[0012] According to the above configuration, the twisted portion can be twisted within an appropriate range relative to the flatwise portion. By making the twist distance between the inner end and the outer end of the twisted portion 1.0 times or more the width of the busbar, it is possible to prevent the resin coating from peeling off from the conductor due to excessive twisting of the twisted portion. Furthermore, by making the twisted portion 3.0 times or less the width of the busbar, it is possible to prevent the proportion of the twisted portion in the bent portion from becoming too large.

[0013] In the busbar, a first twist angle of the first outer end relative to the first inner end and a second twist angle of the second outer end relative to the second inner end are preferably 90° or less. This configuration can prevent the outer end from being twisted excessively relative to the inner end in the twisted portion.

[0014] In the busbar, the first twisted portion and the second twisted portion are preferably twisted in the same direction or in opposite directions. According to the above configuration, the first twisted portion and the second twisted portion may be twisted in the same direction or in opposite directions depending on the layout of the busbar. [Effects of the Invention]

[0015] According to the present invention, by combining a flatwise processed portion and a twisted processed portion in the bent portion, peeling of the resin coating portion from the conductor can be suppressed. [Brief explanation of the drawings]

[0016] [Figure 1]FIG. 1 is a perspective view showing an example of use of the bus bar according to this embodiment. [Figure 2] FIG. 2 is a perspective view of the bus bar according to the present embodiment. [Figure 3] FIG. 3 is a cross-sectional view of the bus bar in this embodiment. [Figure 4] FIG. 4 is an enlarged perspective view of a bent portion of the bus bar according to this embodiment. [Figure 5] FIG. 5 is a plan view illustrating various dimensional relationships of the bent portion in the bus bar according to this embodiment. [Figure 6] FIG. 6 is a cross-sectional view illustrating the twist angle of the bent portion in the bus bar according to this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] A bus bar to which the present invention is applied will be described below with reference to the drawings. [Electric Vehicles] FIG. 1 is a perspective view showing the component layout of an electric vehicle. As shown in FIG. 1, the electric vehicle has a battery pack 1 arranged in the central region of the chassis, for example. The battery pack 1 has an array of battery cells 2, each electrically connected to the others. The battery cells 2 are lithium-ion secondary batteries, nickel-metal hydride secondary batteries, or the like. Component boxes 3a, 3b, and 3c are arranged near the battery pack 1 to house electrical and mechanical components such as a motor, an inverter, a battery pack separate from the battery pack 1, and a gearbox. The battery pack 1 and the component box 3c housing the electrical components are electrically connected by a bus bar 4.

[0018] Meanwhile, electric vehicles and the like are required to improve their comfort performance, which in turn increases power consumption, leading to an increase in the size of the battery pack 1. Therefore, the distance between the battery pack 1 and the component box 3c also increases, and the bus bar 4 is correspondingly lengthened. As an example, the lengthened bus bar 4 has connection terminals 4a at each end. The bus bar 4 extends between two rows of battery cells 2, and one of the connection terminals 4a is electrically connected to a connection located at the end of the battery cell 2. The other connection terminal 4a is electrically connected to a connection that bypasses the component boxes 3a and 3b and is connected to an electrical component in the component box 3c.

[0019] When errors in the length of the elongated busbar 4, such as the length and the bending angle of the bent portion 12, are accumulated, for example, the connection terminal portion 4a provided at the end of the busbar 4 may become misaligned with the connection portion of the battery pack 1, making it impossible to connect the connection terminal portion 4a to the connection portion. In such a case, the busbar 4 can make it possible to connect the connection terminal portion 4a to the connection portion by, for example, readjusting the bending or twist angle of the bent portion 12.

[0020] [Busbar configuration] 2, busbar 4 includes a plurality of straight portions 11 and a plurality of bent portions 12 provided between straight portions 11. Hereinafter, the direction in which busbar 4 extends will be referred to as extension direction E.

[0021] As shown in FIG. 3, the cross-sectional structure includes a conductor 13 made of a rectangular wire and an insulating resin coating 14 covering the conductor 13. The conductor 13 is a conductive rectangular wire whose cross section has been finished into a rectangular shape by rolling or the like. Specifically, the conductor 13 is a conductive metal wire made of copper, aluminum, or the like. If the conductor is copper, it may be tough pitch copper, oxygen-free copper, or the like. The resin coating 14 is made of a resin such as PP (Polypropylene), PE (Polyethylene), PVC (Poly Vinyl Chloride), polyphenylene sulfide, polyamide 12, or polyether ether ketone, which has excellent insulating properties, heat resistance, durability, and the like.

[0022] Resin coating 14 can be provided by extrusion coating, in which a continuous conductor is coated with molten resin and then cooled and solidified. The busbar 4 has bent portions 12 formed after resin coating 14 is provided on conductor 13. Extrusion coating facilitates the manufacture of long busbars 4, and allows for bending after resin coating. Furthermore, resin coating 14 has excellent toughness.

[0023] Alternatively, the resin coating 14 can be formed by painting the conductor 13 after the bent portion 12 is formed thereon. Painting stabilizes the thickness of the resin coating 14. Furthermore, when a thermoplastic resin such as an epoxy resin is used, the coating has high strength and excellent toughness.

[0024] Furthermore, the resin coating 14 can be provided by inserting and shrinking a cylindrical resin film or tube before or after providing the bent portion 12 in the conductor 13. Furthermore, the resin coating 14 can be provided by providing the bent portion 12 in the conductor 13 in advance, and then setting the conductor 13 in a mold and performing injection molding.

[0025] Furthermore, the resin coating portion 14 can be provided by spirally winding a resin tape around the conductor 13 before or after forming the bent portion 12 on the conductor 13. The resin tape may be wound around the conductor 13 in multiple layers. This improves the adhesion and flame retardancy of the resin coating portion 14 to the conductor 13. The resin tape may also be wound around a resin coating formed by extrusion coating, painting, or shrinking a cylindrical resin film or tube.

[0026] 4 is an enlarged perspective view of a bent portion 12. Each bent portion 12 includes a flatwise processed portion 21, a first twist processed portion 22, and a second twist processed portion 23. In the extension direction E, the first twist processed portion 22 is located on one side of the flatwise processed portion 21, and the second twist processed portion 23 is located on the other side.

[0027] As shown in FIG. 5, the flatwise processed portion 21 is a portion of the busbar bent in a planar direction. That is, it is a portion bent by applying force to the long sides of the rectangular cross-sectional shape of the rectangular wire busbar 4. The bending angle θ3 here is, for example, 90°. The bending radius R of the flatwise processed portion 21 is equal to or greater than the thickness of the busbar and is set appropriately depending on the placement location. Here, one end of the flatwise processed portion 21 in the extension direction E is referred to as a first end 21a, and the other end is referred to as a second end 21b.

[0028] The first twisted section 22 is located on the first end 21a side of the flatwise processed section 21. The second twisted section 23 is located on the second end 21b side of the flatwise processed section 21. In the first twisted section 22, the end on the first end 21a side in the extension direction E is the first inner end 22a, and the end on the straight section 11 side is the first outer end 22b. In the second twisted section 23, the end on the second end 21b side in the extension direction E is the second inner end 23a, and the end on the straight section 11 side is the second outer end 23b.

[0029] 6, in the first twist processing section 22, the first twist angle θ1 of the first outer end 22b relative to the first inner end 22a is preferably 90° or less. Furthermore, in the second twist processing section 23, the second twist angle θ2 of the second outer end 23b relative to the second inner end 23a is preferably 90° or less. The twist angles θ1 and θ2 are angles at which the busbar 4 is twisted during twist processing. By setting the twist angles θ1 and θ2 to 90° or less in each of the first twist processing section 22 and the second twist processing section 23, it is possible to prevent the inner end portions 22a and 23a and the outer end portions 22b and 22b from being twisted too much, which can prevent the resin coating 14 from peeling off from the conductor 13.

[0030] The first twist processing portion 22 and the second twist processing portion 23 are twisted in the same direction or in opposite directions. In the examples of Figures 4 and 5, they are twisted in the same direction. The twisting direction is set appropriately depending on the arrangement of the component boxes 3a to 3c.

[0031] The flatwise processed portion 21 and the first twist processed portion 22 may be provided contiguously or with a gap therebetween. That is, the first end portion 21a and the first inner end portion 22a may be located at the same position or may be spaced apart. In other words, the first inner end portion 22a of the first twist processed portion 22 is preferably located between the first end portion 21a of the flatwise processed portion 21 and a position 3.0 times the width W of the busbar 4. The flatwise processed portion 21 and the second twist processed portion 23 may also be provided contiguously or with a gap therebetween. That is, the second end portion 21b and the second inner end portion 23a may be located at the same position or may be spaced apart. In other words, the second inner end portion 23a of the second twist processed portion 23 is preferably located between the second end portion 21b and a position 3.0 times the width W of the busbar 4. Furthermore, the distance between the first end 21a and the first inner end 22a, and the distance between the second end 21b and the second inner end 23a are preferably, for example, within 100 mm.

[0032] With this configuration, the bent portion 12 can be formed by providing the twisted portions 22, 23 near the flatwise processed portion 21. This prevents the proportion of the bent portion 12 to the overall length of the busbar 4 from becoming too large. Note that Figs. 4 and 5 show a state in which the end portions 21a, 21b and the inner end portions 22a, 23a are provided at the same position.

[0033] The first twist distance L1 between the first inner end 22a and the first outer end 22b in the first twisted portion 22 is preferably 1.0 to 3.0 times the width of the busbar 4. Furthermore, the second twist distance L2 between the second inner end 23a and the second outer end 23b in the second twisted portion 23 is preferably 1.0 to 3.0 times the width of the busbar.

[0034] This configuration allows the twisted portions 22, 23 to be twisted within an appropriate range relative to the flatwise portion 21. In each of the first twisted portion 22 and the second twisted portion 23, the twisting distances L1, L2 between the inner ends 22a, 23a and the outer ends 22b, 23b are set to be 1.0 times or more the width W of the busbar 4. This makes it possible to prevent the resin coating 14 from peeling off from the conductor 13 due to excessive twisting of the twisted portions 22, 23. Furthermore, by setting the twisting distances L1, L2 to be 3.0 times or less the width W of the busbar 4, it is possible to prevent the proportion of the twisted portions 22, 23 in the bent portion 12 from becoming too large.

[0035] The busbar 4 configured as described above has the straight portions 11 and bent portions 12 formed by a robot such as a forming machine according to the layout. The distances between the ends 21a, 21b and the inner ends 22a, 23a, the twisting distances L1, L2, the bending angle θ3, and the twisting angles θ1, θ2 are designed according to the arrangement of the battery pack 1 and the component boxes 3a, 3b, and 3c. The busbar 4 is then routed in predetermined positions according to the layout of the battery pack 1 and the component boxes 3a to 3c. The connection terminals 4a of the busbar 4 are electrically connected to the connection portions by welding, soldering, or the like. If the position of the connection terminals 4a is misaligned with respect to the connection portions, the bending angle θ3 of the flatwise processed portion 21 and the twisting angles θ1, θ2 of the twisted portions 22, 23 in each bent portion 12 are adjusted to adjust the position of the connection terminals 4a with respect to the connection portions.

[0036] [Effects of the embodiment] The bus bar 4 as described above can provide the following effects. (1) The busbar 4 has twisted sections 22, 23 on both sides of the flatwise processed section 21 at the bent section 12. The flatwise processed section 21 and the twisted sections 22, 23 have smaller dimensional differences between the inner and outer peripheries of the bent section compared to edgewise processing, making it difficult for the resin coating to lift up from the conductor. Therefore, the busbar 4 can prevent wrinkles and other problems caused by the resin coating 14 peeling off and lifting up from the conductor 13. Furthermore, the absence of wrinkles and other problems improves the appearance.

[0037] (2) The flatwise processed portion 21 allows subsequent adjustment of the bending angle more easily than edgewise processing. The twisted portions 22 and 23 also allow subsequent adjustment more easily than edgewise processing. If the connection terminal portion 4a of the busbar 4 is misaligned with respect to the connection portion of the battery pack 1 or the component box 3c, the bending angle θ3 of the flatwise processed portion 21 and the twist angles θ1 and θ2 of the twisted portions 22 and 23 can be easily adjusted. This allows the connection terminal portion 4a to be electrically connected to the connection portion.

[0038] (3) The inner ends 22a, 23a of the twisted portions 22, 23 are located between the ends 21a, 21b of the flatwise-processed portion 21 and a position 3.0 times the width W of the busbar 4. Therefore, the bent portion 12 can be formed by providing the twisted portions 22, 23 near the flatwise-processed portion 21. Furthermore, by limiting the distance between the ends 21a, 21b of the flatwise-processed portion 21 and the inner ends 22a, 23a of the twisted portions 22, 23 to within 3 times the width W of the busbar 4, the magnitude of the bending radius R of the flatwise-processed portion 21 can be reduced. This prevents the proportion of the bent portion 12 to the total length of the busbar 4 from becoming too large. Furthermore, when the twisted portions 22, 23 are provided, the area of ​​the bent portion 12 increases compared to edgewise processing. In busbar 4, by limiting the distance between ends 21a, 21b and inner ends 22a, 23a to within three times width W of busbar 4, the space occupied by bent portion 12 can be reduced.

[0039] (4) The twist distances L1, L2 between the inner ends 22a, 23a and the outer ends 22b, 23b of the twisted portions 22, 23 are 1.0 to 3.0 times the width of the busbar 4. This prevents the resin coating 14 from peeling off from the conductor 13 due to excessive twisting of the twisted portions 22, 23. It also prevents the proportion of the twisted portions 22, 23 in the bent portion 12 from becoming too large.

[0040] (5) In the twisted portions 22, 23, by setting the twist angles θ1, θ2 to 90° or less, the inner ends 22a, 23a and the outer ends 22b, 22b are not twisted too much, which can prevent the resin coating 14 from peeling off from the conductor 13.

[0041] (6) Twisted portions 22 and 23 are twisted in the same direction or in opposite directions, and the twisting direction can be appropriately set depending on the arrangement of component boxes 3a to 3c.

[0042] (7) The material of the busbar 4 can easily provide the resin coating 14 on the conductor 13 by extrusion coating. The bent portion 12 can be formed using a robot using such a material. The bent portion 12 includes the flatwise processed portion 21 and the twisted portions 22 and 23. Therefore, when the busbar 4 is moved by the robot during installation, it is possible to prevent the busbar 4 from bending in the flat direction. Therefore, the busbar 4 can also be attached to a predetermined position by a robot.

[0043] [Modification] The bus bar 4 as described above may have the following modified examples or a combination of at least two mutually consistent modified examples.

[0044] Among the multiple bent portions 12 in the busbar 4, there may be bent portions 12 in which the twisted portions 22, 23 are twisted in the same direction, or there may be bent portions 12 in which the twisted portions 22, 23 are twisted in opposite directions.

[0045] The twist angles θ1 and θ2 may be the same or different. As long as peeling of the resin coating 14 from the conductor 13 does not occur, the twist angles θ1 and θ2 of the outer ends 22b and 23b relative to the inner ends 22a and 23a may be greater than 90° in the bent portion 12. Furthermore, either one of the twist angles θ1 and θ2 may be greater than 90°.

[0046] As long as peeling of the resin coating 14 from the conductor 13 does not occur, the twisting distances L1, L2 between the inner ends 22a, 23a and the outer ends 22b, 23b in the twisted portions 22, 23 may be less than 1.0 times the width of the busbar 4. Also, there may be bent portions 12 in which the twisting distances L1, L2 are more than 3.0 times the width of the busbar 4. The first twisting distance L1 and the second twisting distance L2 may be the same length or different lengths. Also, either the first twisting distance L1 or the second twisting distance L2 may be outside the range of 1.0 to 3.0 times the width W of the busbar 4.

[0047] Depending on the layout, the inner ends 22a, 23a of the twisted portions 22, 23 may be spaced apart from the ends 21a, 21b of the flatwise processed portion 21 by more than 3.0 times the width W of the busbar 4. Also, either one of the inner ends 22a, 23a of the twisted portions 22, 23 may be spaced apart from the ends 21a, 21b of the flatwise processed portion 21 by more than 3.0 times the width W of the busbar 4.

[0048] The number of bent portions 12 in the bus bar 4 is determined depending on the arrangement of the battery pack 1 and the component boxes 3a to 3c, and is not particularly limited. The bus bar 4 may be used for electrical connection between the battery pack 1 and the component box 3c of an electric vehicle, as well as for use in a distribution board, a control board, etc. [Explanation of symbols]

[0049] 1. Battery pack 2...Battery cell 3a~3c...Parts box 4...Busbar 4a...Connection terminal 11...Straight section 12...Bent section 13...conductor 14...Resin coated part 21...Flatwise processing section 21a...first end 21b…Second end 22...First twist processing section 22a...first inner end 22b...First outer end 23...Second twist processing section 23a…Second inner end 23b…Second outer end

Claims

1. A bus bar including a conductor made of a rectangular wire and an insulating resin coating covering the conductor, the bus bar includes a bent portion; The direction in which the bus bar extends is an extension direction, The bent portion includes a flatwise processed portion, a first twist processed portion on one side in the extension direction of the flatwise processed portion, and a second twist processed portion on the other side. Busbar.

2. In the extension direction, a first inner end portion of the first twisted portion is located between a first end portion of the flatwise processed portion and a position that is 3.0 times the width of the bus bar; A second inner end of the second twisted portion is located between the second end of the flatwise processed portion and a position 3.0 times the width of the bus bar. The busbar of claim 1 .

3. In the extension direction, A first twist distance between a first inner end and a first outer end in the first twist processed portion, and a second twist distance between a second inner end and a second outer end in the second twist processed portion are The width is 1 to 3.0 times the width of the bus bar. The busbar of claim 1 .

4. a first twist angle of the first outer end relative to the first inner end and a second twist angle of the second outer end relative to the second inner end are less than or equal to 90°; The bus bar according to claim 3 .

5. The first twisted portion and the second twisted portion are twisted in the same direction or in opposite directions. The busbar of claim 1 .

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