Wiring material and battery pack

Abstract

The present invention comprises: a fire-resistant insulating tape (20) that is wound in an overlapping manner in a range including a flat cable of a wiring material body (10); a fixing portion (30) that fixes one end of the fire-resistant insulating tape (20) to the wiring material body (10); and a fixing portion (31) that fixes the other end of the fire-resistant insulating tape (20) to the wiring material body (10), wherein the fire-resistant insulating tape (20) and the flat cable are not adhered to each other.

Description

Wiring material and battery pack

[0001] The present invention relates to a wiring material and a battery pack.

[0002] As a wiring material with improved fire resistance, there is known a wiring material including a core wire, a fire-resistant tape spirally wound around the core wire, and a fire-resistant retaining thread wound around the fire-resistant tape (see, for example, Patent Document 1). In the wiring material described in Patent Document 1, an attempt is made to maintain fire resistance by restraining the fire-resistant tape with the retaining thread so that no gap is formed in the overlapping portion of the fire-resistant tape even when the wiring material is bent.

[0003] Japanese Patent Application Laid-Open No. 2018-181516

[0004] With the increasing size of battery packs mounted in electric vehicles, the distance between components inside the battery pack has been expanding and the configuration of components has been becoming more complex. As a result, assembly interference has increased and constraints on assembly procedures have increased, so wiring materials that connect components are required to have the property of being bendable by an external force applied by an operator (flexibility, softness). Since wiring materials used for connections between components in a battery pack are required to have fire resistance and insulation properties in addition to flexibility and softness, it is conceivable to spirally wrap a tape having fire resistance and insulation properties around a flexible and soft cable.

[0005] However, when the fire-resistant tape is restrained by a retaining thread as in the wiring material described in Patent Document 1, or when the fire-resistant tape is adhered to the cable, the bending of the wiring material is inhibited by the fire-resistant tape because the fire-resistant tape does not have flexibility and softness.

[0006] In view of the above circumstances, an object of the present invention is to provide a fire-resistant and insulating wiring material in which the bendability by an external force is ensured, and a battery pack including the wiring material.

[0007] The wiring material of the present invention includes: a wiring material main body including a bent portion bendable by an external force; a covering material having fire resistance and insulation properties that is wrapped in an overlapping manner around a range including the bent portion of the wiring material main body; a first fixing portion that fixes one end side of the covering material to the wiring material main body; and a second fixing portion that fixes the other end side of the covering material to the wiring material main body, wherein the covering material and the bent portion are not adhered to each other.

[0008] The battery pack of the present invention comprises a plurality of components including a plurality of batteries, and a wiring material that electrically connects the components, wherein the wiring material comprises a wiring material body having a curved portion that bends under external force, a fire-resistant and insulating covering material that is wound in overlapping manner over the wiring material body including the curved portion, a first fixing portion that fixes one end of the covering material to the wiring material body, and a second fixing portion that fixes the other end of the covering material to the wiring material body, wherein the covering material and the curved portion are not adhered to each other.

[0009] According to the present invention, the property of a fire-resistant insulating cable material to bend under external force can be ensured.

[0010] Figure 1 is a perspective view showing a battery pack equipped with a cable guide according to one embodiment of the present invention. Figure 2 is a perspective view showing the state of the battery pack shown in Figure 1 before adjacent battery modules are connected to each other. Figure 3 is a perspective view showing the state of the battery pack shown in Figure 1 during the process of connecting adjacent battery modules to each other. Figure 4 is a front view showing the main body of the cable guide shown in Figure 1. Figure 5 is a front view showing the cable guide shown in Figure 1. Figure 6 is a cross-sectional view taken along line VI-VI in Figure 5. Figure 7 is an enlarged front view showing a part of the cable guide shown in Figure 5. Figure 8 is a front view showing the cable guide shown in Figure 5 bent by an external force. Figure 9 is a front view showing a cable guide according to another embodiment of the present invention.

[0011] The present invention will be described below in accordance with preferred embodiments. However, the present invention is not limited to the embodiments shown below, and the embodiments shown below can be modified as appropriate without departing from the spirit of the invention. Furthermore, in the embodiments shown below, some components are not illustrated or described; however, details of the omitted technologies can be appropriately applied from publicly known or well-known technologies, to the extent that they do not contradict the content described below.

[0012] Figure 1 is a perspective view showing a battery pack P equipped with a wiring member 1 according to one embodiment of the present invention. The battery pack P shown in this figure is a drive battery pack mounted on an electric vehicle and comprises a plurality of battery modules M. A battery module M is a battery module in which a plurality of battery cells (not shown) are connected. The battery cells are cells of secondary batteries such as lithium-ion batteries and nickel-metal hydride batteries.

[0013] The cable routing material 1 is a fire-resistant insulated cable that can ensure insulation even at high temperatures, making it suitable for use in an in-vehicle battery pack P. The cable routing material 1 comprises a cable routing material body 10, a fire-resistant insulating tape 20 spirally wound around the cable routing material body 10, and fixing parts 30 and 31 for fixing the fire-resistant insulating tape 20 to the cable routing material body 10. The fixing part 30 fixes one end of the fire-resistant insulating tape 20 in the longitudinal direction to one end of the cable routing material body 10 in the extending direction, and the fixing part 31 fixes the other end of the fire-resistant insulating tape 20 in the longitudinal direction to the other end of the cable routing material body 10 in the extending direction.

[0014] Figure 2 is a perspective view showing the state of the battery pack P shown in Figure 1 before adjacent battery modules M are connected to each other. Figure 3 is a perspective view showing the state of the battery pack P shown in Figure 1 during the process of connecting adjacent battery modules M. As shown in these figures, the cable material 1 has the property of bending under external force (flexibility, flexibility), and can freely change between a straightened state (see Figure 2) and a bent (flexible) state (see Figure 3).

[0015] As shown in Figure 3, the cable guide 1 connects the terminals T of adjacent battery modules M. Here, even if the tolerances for the dimensions and positions of the terminals T are set to be large, the bending (flexibility) of the cable guide 1 makes it easier to align the terminal portion 11 of the cable guide 1 (see Figure 4) with the terminals T of the battery modules M during the connection work. Furthermore, even if there are constraints on the assembly procedure, the bending of the cable guide 1 increases the degree of freedom in handling the cable guide 1 during the connection work. Therefore, regardless of the magnitude of the tolerances for the dimensions and positions of the terminals T, or the constraints on the assembly procedure, it becomes possible to connect the terminals T of the battery modules M.

[0016] Figure 4 is a front view showing the main body 10 of the cable routing material shown in Figure 1. As shown in this figure, the main body 10 of the cable routing material comprises a pair of terminal portions 11 and a flat cable 12 connecting the pair of terminal portions 11. The terminal portion 11 is an L-shaped plate made of a highly conductive metal such as copper. The terminal portion 11 comprises a terminal connection portion 11A and a cable connection portion 11B.

[0017] The pair of terminal sections 11 are arranged apart in the direction of extension of the flat cable 12 such that their terminal connection sections 11A face each other in the direction of extension of the flat cable 12. A circular hole (see Figure 3) is formed in the terminal connection section 11A of one terminal section 11, and an elongated hole (see Figure 3) is formed in the terminal connection section 11A of the other terminal section 11. The terminal T of one battery module M to be connected is inserted through the circular hole in the terminal connection section 11A of one terminal section 11, and the terminal T of the other battery module M to be connected is inserted through the elongated hole in the terminal connection section 11A of the other terminal section 11.

[0018] Multiple conductors 12A (see Figure 6) of the flat cable 12 are connected to one side (the front side in Figure 4) of each cable connection portion 11B. The multiple conductors 12A are arranged perpendicular to the extending direction of the flat cable 12 and parallel to one side of the cable connection portion 11B. The conductors 12A are covered with an insulator 12B (see Figure 6) and inserted into a sheath 12C.

[0019] The sheath 12C is flattened to reduce the height of the cable conductor 1. The width direction of the sheath 12C coincides with the direction in which the multiple conductors 12A are arranged (up and down direction in Figure 6), and the thickness direction of the sheath 12C coincides with the thickness direction of the cable connection portion 11B (front and back direction in Figure 4). Both ends of the multiple conductors 12A are exposed from the insulator 12B and the sheath 12C and are connected to the cable connection portion 11B.

[0020] The flat cable 12 is a highly flexible cable that can bend (flex) in the width and thickness directions due to external force. The distance between the pair of terminal connection points 11A is set to be slightly longer than the distance between the terminals T of the pair of battery packs P to be connected. Therefore, the cable 1 is attached to the pair of battery packs P to be connected with the flat cable 12 slightly slack.

[0021] Figure 5 is a front view showing the cable routing material 1 shown in Figure 1. As shown in this figure, in the cable routing material 1, the fire-resistant insulating tape 20 is spirally wrapped over the cable from one cable connection part 11B to the other cable connection part 11B.

[0022] The fire-resistant insulating tape 20 is a strip-shaped body that has fire-resistant and insulating properties. Examples of fire-resistant insulating tape 20 include a strip-shaped body with a laminated structure in which a fire-resistant base layer (glass fiber, ceramic material, heat-resistant polymer, etc.), an adhesive layer (silicone adhesive, etc.), an insulating layer (polyimide, silicone, etc.), and an outer layer (polyimide, silicone, etc.) are laminated, and a strip-shaped body with a single-layer structure consisting only of a base layer (silica, glass fiber, polyimide, etc.) that has fire-resistant and insulating properties.

[0023] Here, no adhesive layer is provided on either the front or back surface of the fire-resistant insulating tape 20. Therefore, the fire-resistant insulating tape 20 is not adhered to the flat cable 12 and the cable connection part 11B. Furthermore, in the overlapping portion of the fire-resistant insulating tape 20, the front and back surfaces that come into contact with each other are not adhered. Therefore, when the flat cable 12 is bent (flexed), the overlapping portion of the fire-resistant insulating tape 20 slides, causing the covering layer made of the fire-resistant insulating tape 20 to follow and bend. Note that when using fire-resistant insulating tape with an adhesive surface on the back, insulating paper should be placed on the back so as to cover the adhesive surface.

[0024] Fixing part 30 is a tape that fixes one end of the covering layer made of fire-resistant insulating tape 20 in the direction of extension to one cable connection part 11B, and fixing part 31 is a tape that fixes the other end of the covering layer made of fire-resistant insulating tape 20 in the direction of extension to the other cable connection part 11B. Fixing part 30 is wrapped around the covering layer made of fire-resistant insulating tape 20 so as to straddle one end in the direction of extension and one cable connection part 11B. Fixing part 31 is wrapped around the covering layer made of fire-resistant insulating tape 20 so as to straddle the other end in the direction of extension and the other cable connection part 11B. Note that since the fire-resistant insulating tape 20 maintains its shape by carbonizing and hardening when heated, the fixing part 30 is not particularly required to be fire-resistant.

[0025] Figure 6 is a cross-sectional view taken along line VI-VI in Figure 5. As shown in this figure, the cross-sectional shape of the flat cable 12 (the cross-section perpendicular to the conductor 12A) is rectangular, with the longitudinal direction being the direction in which the multiple conductors 12A are aligned (up and down in the figure), and is composed of a pair of long sides and a pair of short sides. That is, the outer surface of the flat cable 12 is composed of a pair of wide surfaces that constitute the pair of long sides of the cross-section and a pair of narrow surfaces that constitute the pair of short sides of the cross-section.

[0026] Here, the fire-resistant insulating tape 20 is in close contact with the pair of narrow surfaces of the flat cable 12, but not with the entire surface of the pair of wide surfaces of the flat cable 12. That is, there is no gap between the fire-resistant insulating tape 20 and the pair of narrow surfaces of the flat cable 12, but there is a gap between the fire-resistant insulating tape 20 and the pair of wide surfaces of the flat cable 12. As a result, the close contact between the fire-resistant insulating tape 20 and the pair of narrow surfaces of the flat cable 12 prevents gaps from forming in the overlapping portion of the fire-resistant insulating tape 20. On the other hand, the fact that the fire-resistant insulating tape 20 is not in close contact with the entire surface of the pair of wide surfaces of the flat cable 12 prevents the overlapping portion of the fire-resistant insulating tape 20 from sliding, thus preventing the overall flexibility of the fire-resistant insulating tape 20 from being hindered.

[0027] Figure 7 is a front view showing an enlarged portion of the cable routing material 1 shown in Figure 5. As shown in this figure, the fire-resistant insulating tape 20 is wrapped around the flat cable 12 in a so-called half-wrap winding manner, where the overlap width W2 is half the width W1 of the fire-resistant insulating tape 20. Note that it is not essential to wrap the fire-resistant insulating tape 20 in a half-wrap winding manner, that is, to make the ratio r (= W2 / W1) of the overlap width W2 to the width W1 1 / 2; the ratio r can be between 1 / 10 and 1 / 2. If the ratio r is less than 1 / 10, the overlap winding work of the fire-resistant insulating tape 20 becomes difficult. On the other hand, if the ratio r exceeds 1 / 2, the required length of the fire-resistant insulating tape 20 becomes excessive, resulting in high costs, or the overlapping portion of the fire-resistant insulating tape 20 does not slide, hindering the overall flexibility of the fire-resistant insulating tape 20.

[0028] Figure 8 is a front view showing the cable routing member 1 shown in Figure 5 in a state where it is bent due to an external force. As shown in this figure, in the cable routing member 1 in the state where it is bent due to an external force, the curvature differs between one end (hereinafter referred to as the inner circumference side) and the other end in the width direction of the cable routing member 1, and the side where the curvature of the flat cable 12 is larger (hereinafter referred to as the outer circumference side) is extended.

[0029] Here, if the width W1 of the fire-resistant insulating tape 20 is set to twice the difference in total length between the outer and inner circumferences of the flat cable 12 when it is bent to its maximum extent by external force (hereinafter referred to as the design flexibility), then the ratio r should be set to 1 / 2. Also, if the width W1 of the fire-resistant insulating tape 20 is set to three times the design flexibility of the flat cable 12, then the ratio r should be set to 1 / 3, and if the width W1 of the fire-resistant insulating tape 20 is set to 1.5 times the design flexibility of the flat cable 12, then the ratio r should be set to 3 / 4. However, as mentioned above, from the viewpoint of cost, a ratio r of 1 / 2 or less is preferable.

[0030] As described above, the cable routing member 1 according to this embodiment comprises a cable routing member body 10 equipped with a flat cable 12 that bends under external force, a fire-resistant insulating tape 20 that is wrapped around the cable routing member body 10 in an overlapping manner over the area including the flat cable 12, a fixing part 30 that fixes one end of the fire-resistant insulating tape 20 to the cable routing member body 10, and a fixing part 31 that fixes the other end of the fire-resistant insulating tape 20 to the cable routing member body 10.

[0031] Here, the fire-resistant insulating tape 20 is fixed to the cable routing material body 10 at one end by a fixing part 30 and to the cable routing material body 10 at the other end by a fixing part 31, but is not adhesive to the flat cable 12. Therefore, when an external bending force is applied to the cable routing material 1, the bending of the flat cable 12 is prevented from being hindered by the fire-resistant insulating tape 20, and the property of the fire-resistant insulating cable routing material 1 to bend under external force is ensured.

[0032] Furthermore, in the cable routing material 1 according to this embodiment, the flat cable 12 extends along the extending direction of the cable routing material body 10, and the fire-resistant insulating tape 20 is spirally wound along the extending direction of the cable routing material body 10. When the flat cable 12 bends due to an external force, the overlapping portion of the fire-resistant insulating tape 20 slides. This prevents gaps from forming in the overlapping portion of the fire-resistant insulating tape 20 when a bending external force is applied to the cable routing material 1, and prevents the bending of the flat cable 12 from being hindered by the fire-resistant insulating tape 20.

[0033] Furthermore, in the cable routing material 1 according to this embodiment, the overlap width W2 of the fire-resistant insulating tape 20 is set to be greater than or equal to the amount of deformation (design flexibility) of the fire-resistant insulating tape 20 in the direction along the width direction of the flat cable 12 when it is bent by an external force. Therefore, when a bending external force is applied to the cable routing material 1 and the flat cable 12 bends, it is possible to prevent gaps from forming in the overlapping portion of the fire-resistant insulating tape 20.

[0034] Furthermore, in the wiring material 1 according to this embodiment, the overlap width W2 of the fire-resistant insulating tape 20 is 1 / 10 to 1 / 2 of the width W1 of the fire-resistant insulating tape 20. This ensures ease of overlapping the fire-resistant insulating tape 20, avoids unnecessary cost increases, and ensures the overall flexibility of the fire-resistant insulating tape 20 by allowing the overlapping portion of the fire-resistant insulating tape 20 to slide, while preventing gaps from forming in the overlapping portion of the fire-resistant insulating tape 20.

[0035] Figure 9 is a front view showing a cable routing member 100 according to another embodiment of the present invention. As shown in this figure, the cable routing member 100 comprises a cable routing member body 110, a fire-resistant insulating tape 20, and fixing parts 30 and 31. Components similar to those in the above-described embodiment are denoted by the same reference numerals, and the description of the above-described embodiment will be used by reference.

[0036] The cable routing member body 110 comprises a pair of terminal sections 11, a flat cable 12, and a pair of protectors 13. Each protector 13 accommodates the cable connection section 11B of the terminal section 11 and the end of the flat cable 12, and restrains the end of the flat cable 12. Therefore, the range in which the flat cable 12 bends due to external force (flexible range) 12F is limited to the central part in the direction of extension of the flat cable 12.

[0037] The fire-resistant insulating tape 20 is spirally wrapped around one protector 13 to the other protector 13. That is, the fire-resistant insulating tape 20 is spirally wrapped around the flexible range 12F of the flat cable 12, but not around the entire flat cable 12.

[0038] The fixing part 30 is wrapped around one end of the covering layer made of fire-resistant insulating tape 20 in the direction of extension and one protector 13 so as to straddle them, and fixes one end of the covering layer made of fire-resistant insulating tape 20 in the direction of extension to one protector 13. The fixing part 31 is wrapped around the other end of the covering layer made of fire-resistant insulating tape 20 in the direction of extension and the other protector 13 so as to straddle them, and fixes the other end of the covering layer made of fire-resistant insulating tape 20 in the direction of extension to the other protector 13.

[0039] Although the present invention has been described above based on the above embodiments, the present invention is not limited to the above embodiments, and modifications may be made to the above embodiments without departing from the spirit of the present invention, or publicly known or well-known technologies may be combined as appropriate.

[0040] For example, in the above embodiment, the curved portions of the cable members 10 and 110 are made of flat cables 12, but they are not limited to flat cables 12; they may be made of other flexible wires such as cables with a circular cross-sectional shape. Also, the cross-sectional shape of the flat cable 12 is not limited to a rectangular shape; it may be an elliptical or other flattened shape.

[0041] Furthermore, in the above-described embodiment, the components of the battery pack P connected by the cable 1,100 were defined as a battery module M, but battery cells, a battery management system, a cooling / temperature control system, sensors, etc., may also be used as components of the battery pack P connected by the cable 1,100.

[0042] Furthermore, in the above-described embodiment, the conductor 12A is covered with an insulator 12B and then with a sheath 12C, but this is not essential. Alternatively, the conductor 12A may be covered with fire-resistant insulating tape 20, and the fire-resistant insulating tape 20 may be covered with a protector 13.

[0043] Here, the characteristics of the embodiments of the wiring material and the battery pack according to the present invention described above are briefly summarized and listed below in [1] to [5], respectively. [1] A wiring material (1) comprising: a wiring material main body (10) provided with a bent portion (12) that bends due to an external force; a covering material (20) having fire resistance and insulating properties that is overlap-wound around a range including the bent portion (12) of the wiring material main body (10); a first fixing portion (30) that fixes one end side of the covering material (20) to the wiring material main body (10); and a second fixing portion (31) that fixes the other end side of the covering material (20) to the wiring material main body (10), wherein the covering material (20) and the bent portion (12) are not bonded to each other. [2] The wiring material (1) according to [1], wherein the bent portion (12) extends along the extending direction of the wiring material main body (10), the covering material (20) is spirally overlap-wound along the extending direction of the bent portion (12), and overlapping portions of the covering material (20) slide when the bent portion (12) bends due to an external force. [3] The wiring material (1) according to [1] or [2], wherein an overlap width of the covering material (20) is set to be equal to or larger than a deformation amount of the bent portion (12) bent by an external force in a direction along the width direction of the covering material (20). [4] The wiring material (1) according to [1] or [2], wherein an overlap width of the covering material (20) is not less than 1 / 10 and not more than 1 / 2 of a width of the covering material (20). [5] A battery pack (P) comprising: a plurality of component parts (M) including a plurality of batteries; and a wiring material (1) that electrically connects the component parts (M) to each other, wherein the wiring material (1) comprises: a wiring material main body (10) provided with a bent portion (12) that bends due to an external force; a covering material (20) having fire resistance and insulating properties that is overlap-wound around a range including the bent portion (12) of the wiring material main body (10); a first fixing portion (30) that fixes one end side of the covering material (20) to the wiring material main body (10); and a second fixing portion (31) that fixes the other end side of the covering material (20) to the wiring material main body (10), wherein the covering material (20) and the bent portion (12) are not bonded to each other.

[0044] Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention.

[0045] This application is based on Japanese Patent Application No. 2025-27576 filed on February 25, 2025, the contents of which are incorporated herein by reference.

[0046] According to the present invention, it is possible to provide a wiring material and a battery pack that can ensure the property of bending under external force for fire-resistant insulating wiring materials. The present invention, which achieves this effect, is useful with respect to wiring materials and battery packs.

[0047] 1: Cable routing material 10: Cable routing material body 12: Flat cable (bent section) 12F: Flexible range (bent section) 20: Fire-resistant insulating tape (covering material) 30: Fixing part (first fixing part) 31: Fixing part (second fixing part) 100: Cable routing material 110: Cable routing material body M: Battery module (battery, components) P: Battery pack W1: Width W2: Overlap width

Claims

1. A cable routing material comprising: a main body of the cable routing material having a curved portion that bends due to external force; a fire-resistant and insulating covering material that is wound in overlapping manner over the area of ​​the cable routing material main body including the curved portion; a first fixing portion that fixes one end of the covering material to the cable routing material main body; and a second fixing portion that fixes the other end of the covering material to the cable routing material main body, wherein the covering material and the curved portion are not adhered to each other.

2. The cable routing member according to claim 1, wherein the curved portion extends along the extending direction of the cable routing member body, the covering material is spirally wound along the extending direction of the curved portion, and the overlapping portion of the covering material slides when the curved portion is bent by an external force.

3. The cable guide according to claim 1 or 2, wherein the overlap width of the covering material is set to be greater than or equal to the amount of deformation in the direction along the width direction of the covering material at the bent portion bent by an external force.

4. The cable routing material according to claim 1 or 2, wherein the overlap width of the covering material is 1 / 10 or more and 1 / 2 or less of the width of the covering material.

5. A battery pack comprising multiple components including multiple batteries, and a wiring material for electrically connecting the components, wherein the wiring material comprises a wiring material body having a curved portion that bends under external force, a fire-resistant and insulating covering material wound in overlapping fashion over the wiring material body including the curved portion, a first fixing portion for fixing one end of the covering material to the wiring material body, and a second fixing portion for fixing the other end of the covering material to the wiring material body, wherein the covering material and the curved portion are not adhered to each other.

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