Busbar protection cover and method of constructing same

Abstract

A cover for providing protection to a busbar used to interconnect cells in an electric vehicle battery and a method of construction thereof are provided. The cover includes an impermeable layer, an adhesive layer, and a fabric wall sandwiched between the impermeable layer and the adhesive layer. The adhesive layer is provided for quick and easy attachment of the cover to a desired portion of the busbar, and the cover is configured to cover any desired area of ​​the busbar and conform to selected portions or the entire busbar.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 63 / 284,009, filed November 30, 2021, the entire contents of which are incorporated herein by reference.

[0002] 2. Background of the Invention 1.Technical Field The present invention relates generally to protective covers for protecting elongated members contained therein, and more particularly to fire-resistant, dielectric protective covers for elongated members of an electric vehicle battery pack.

[0003] 2. Related Technologies It is known to encase elongated members, such as bus bars in an electric vehicle battery pack, in a circumferentially continuous tubular wall sleeve to protect the elongated members from impact and abrasion, fluid and external heat effects. However, continuous tubular wall sleeves are difficult to assemble, especially over connectors, have thick walls, are inflexible, and take up valuable design space. There remains a need for a protective cover that can provide dielectric fire protection to the elongated members housed therein, while being flexible, thin, and conforming around the elongated members and their connectors in a manner that is not cumbersome, unsightly, or bulky. There is a further need to have a protective cover that can protect the bus bar connections between the cells of the batteries of an electric vehicle battery system to allow the vehicle to remain drivable under power from the battery system for at least five minutes after a thermal runaway condition of one or more of the battery cells, allowing the electric vehicle operator sufficient time to safely maneuver to a suitable parking location and evacuate the vehicle.

[0004] Summary of the Invention One object of the present disclosure is to provide a cover that encases an elongated member and provides dielectric fire protection to the elongated member.

[0005] Another object of the present disclosure is to provide protection to the bus bar connections between cells of the batteries in an electric vehicle battery system to allow an operator of the electric vehicle sufficient time to safely maneuver to a suitable parking location and evacuate the vehicle.

[0006] Another object of the present disclosure is to provide protection to the bus bar connections between the cells of the batteries of an electric vehicle battery system with an adhesive cover (patch) to enable the battery system to power the electric vehicle for more than five minutes.

[0007] Another object of the present disclosure is to provide a cover (also called a patch) that self-adheres to a busbar for forming a connection between cells of a battery in an electric vehicle battery system, whereby the cover fits around and protects at least a portion of the busbar.

[0008] In accordance with these and other objects, a cover (also called a patch) is provided for providing protection to a busbar used to interconnect cells in an electric vehicle battery. The cover includes a fabric wall formed of a flame retardant material, an impermeable layer attached to the fabric wall, and an adhesive layer attached to the fabric wall, the fabric wall being sandwiched between the impermeable layer and the adhesive layer. The adhesive layer is provided for quick and easy attachment of the cover to a desired portion or the entirety of the busbar, and the cover is shaped to cover any desired area of ​​the busbar and conforms to selected portions or the entirety of the busbar.

[0009] According to another aspect of the present disclosure, the fabric wall may be made from interlaced flame retardant multifilament yarns.

[0010] According to another aspect of the present disclosure, the flame retardant multifilament yarn is a mineral yarn.

[0011] According to another aspect of the present disclosure, the mineral yarns include fiberglass yarns, silica yarns, and / or basalt yarns.

[0012] According to another aspect of the present disclosure, the interlaced yarns are either woven, braided, or knitted.

[0013] According to another aspect of the present disclosure, the impermeable layer may be any of a silicone layer, a silicone-based layer, a mica-based layer, a liquid silicone rubber layer, a polytetrafluoroethylene layer, or a polyurethane layer that is directly adhered to the fabric wall.

[0014] According to another aspect of the present disclosure, the impermeable layer may be provided as a liquid or powder mixture that is applied to the fabric wall.

[0015] According to another aspect of the present disclosure, the impermeable layer may be a solid sheet material laminated to the fabric wall via an intermediate flame retardant adhesive layer.

[0016] According to another aspect of the present disclosure, the adhesive layer may be a self-adhesive layer configured to be selectively exposed for adhesion to the elongate member.

[0017] According to another aspect of the disclosure, the fabric wall, the impermeable layer, and the adhesive layer may form a pre-formed patch configured to conform and fixedly attach to the busbar by the adhesive layer adhering to the busbar.

[0018] According to another aspect of the disclosure, a release film may be attached to the adhesive layer, the release film being selectively removable from the adhesive layer to expose the adhesive layer so that the adhesive layer adheres to the bus bar.

[0019] According to another aspect of the present disclosure, a cover for protecting a bus bar connecting cells of a battery of an electric vehicle includes a fabric wall formed of a flame-retardant material, an impermeable layer attached to the fabric wall, and an adhesive layer attached to the fabric wall, wherein the fabric wall is sandwiched between the impermeable layer and the adhesive layer.

[0020] According to another aspect of the disclosure, a method of constructing a cover to provide flame-retardant dielectric protection for a busbar interconnecting cells of an electric vehicle battery includes forming a fabric wall formed of a flame-retardant material, attaching an impermeable layer to the fabric wall, and attaching an adhesive layer to the fabric wall such that the fabric wall is sandwiched between the impermeable layer and the adhesive layer, the adhesive layer being oriented to be secured to the busbar.

[0021] According to another aspect of the disclosure, the method may further include attaching a release film to the adhesive layer, the release film being selectively removable from the adhesive layer to expose the adhesive layer so that the adhesive layer adheres to the bus bar.

[0022] According to another aspect of the present disclosure, the method may further include providing an impermeable layer, which is either a silicone layer, a silicone-based layer, a mica-based layer, a liquid silicone rubber layer, a polytetrafluoroethylene layer, or a polyurethane layer.

[0023] According to another aspect of the present disclosure, the method may further include forming an impermeable layer from a liquid or powder mixture that is applied to the fabric wall.

[0024] According to another aspect of the present disclosure, the method may further include forming the impermeable layer from a solid sheet material laminated to the fabric wall via an intermediate flame retardant adhesive layer.

[0025] According to another aspect of the present disclosure, the method may further include forming a fabric wall by interlacing the flame retardant multifilament yarns with each other.

[0026] According to another aspect of the present disclosure, the method may further include providing the flame retardant multifilament yarn as a mineral yarn.

[0027] According to another aspect of the present disclosure, the method may further include providing a mineral yarn comprising at least one of a fiberglass yarn, a silica yarn, and a basalt yarn.

[0028] According to another aspect of the present disclosure, the method may further include interlacing the flame retardant multifilament yarn via a weaving, braiding or knitting process.

[0029] According to another aspect of the present disclosure, the method may further include forming the fabric wall in a nonwoven process to provide the fabric wall as a nonwoven layer.

[0030] BRIEF DESCRIPTION OF THE DRAWINGS These and other aspects, features and advantages will become readily apparent to those of ordinary skill in the art in light of the following detailed description of the currently preferred and best modes, the appended claims, and the accompanying drawings. [Brief description of the drawings]

[0031] [Figure 1] FIG. 1 is a perspective view of a vehicle having a cover constructed in accordance with one aspect of the present disclosure attached to the bus bars of an electric vehicle battery. [Diagram 2] 2 is a schematic plan view of the bus bar, showing a state before a pair of covers for protecting the bus bar are attached. FIG. [Figure 2A] FIG. 2A is a cross-sectional view taken generally along line 2A-2A of FIG. [Figure 2B] 2B is a view similar to FIG. 2A of a cover constructed according to another embodiment of the present disclosure. [Diagram 3] FIG. 3 is an assembly diagram of a cover attached to the bus bar of FIG. 2. [Figure 3A] 3A is a cross-sectional view at the end taken generally along line 3A-3A of FIG. 3. [Figure 3B] 3B is a view similar to FIG. 3A of a cover constructed in accordance with another embodiment of the present disclosure and attached to a bus bar. [Figure 4] 3, but showing a pair of covers attached to the busbar of FIG. 2, constructed in accordance with another aspect of the present disclosure. [Figure 4A]4A is a cross-sectional view at the end taken generally along line 4A-4A of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] Detailed Description of the Preferred Embodiments Referring more particularly to the drawings, Fig. 1 shows a flexible protective cover constructed in accordance with one embodiment of the present invention having a laminated structure, hereinafter referred to as patch 10, which includes a fabric wall 12 formed of a flame retardant material, an impermeable layer 14 attached to the outer surface of the fabric wall 12, and an adhesive layer 16 attached to the inner surface of the fabric wall 12, as best shown in Fig. 2A. Thus, the fabric wall 12 is sandwiched between the outermost impermeable layer 14 and the innermost adhesive layer 16. The patch 10 may be used as a single member (a single laminate of the aforementioned layers), or the patch 10 may be used as a multiple member (multiple laminates of the aforementioned layers), as shown as a pair of patches 10, configured to be adhered to an elongated member 11 via the adhesive layer 16 in a mirror symmetrical manner to each other, to protect the elongated member 11, such as a bus bar interconnecting adjacent cells of a battery pack B of a vehicle, such as an electric vehicle EV. Thus, one patch 10 may be applied to one surface 15 of the busbar 11 and the other patch 10 may be applied to the opposite surface 15 of the busbar 11. This has been found to be particularly useful for covering non-straight busbars 11 having bends, such as 90 degree bends, by way of example and not limitation, where opposing patches 10 having mirror images of one another, referred to as busbar covers, may be provided which can cover the non-straight busbar 11 without significantly bending or deforming the individual patches 10 to provide a protective cover which conforms and fits tightly around the busbar 11 whilst avoiding the formation of wrinkles. The opposing ends of the patches 10 may be joined together by a butt joint (FIG. 3A) or overlap each other (FIG. 3B) to cover the entire circumference of the busbar.In this manner, the patch 10, or multiple patches 10, by way of example and not limitation, provide uniform protection to and around the busbar 11 against impact forces, abrasion, and ingress of dirt that may occur in a vehicle collision, etc., and further, the patch 10, or multiple patches 10, not only provide impact protection but also inhibit the spread of fire, such as in the event of thermal runaway of one or more cells of battery pack B, thereby allowing the electric vehicle EV to continue to be powered by battery B for five minutes or more and the electric vehicle EV to be safely maneuvered to a suitable parking location where the driver can evacuate the electric vehicle EV.

[0033] The fabric wall 12 may be made of interlaced flame-retardant multifilament yarns 18. The flame-retardant multifilament yarns 18 may be provided partially or entirely as mineral yarns, which may include fiberglass yarns, silica yarns, and / or basalt yarns. The multifilament yarns 18 may be provided as a plurality of separate yarns that are interlaced with one another by a weaving, braiding, or knitting process, thus providing the fabric wall 12 having a woven, braided, or knitted structure. According to another aspect of the present disclosure, the fabric wall 12 may be made as a flame-retardant nonwoven layer (FIG. 2B), such as by air-laid or carding processes, as examples and not by way of limitation.

[0034] The impermeable layer 14 is provided to prevent the ingress, absorption, penetration, and passage of fluids, dust, particles, and smoke into the fabric wall 12, improving the flame retardant and improving fire protection of the patch 10. The impermeable layer 14 can be provided to be stretchable in all directions, including longitudinally and radially, such that the underlying fabric wall 12 remains stretchable along the longitudinal and radial directions, and the impermeable layer 14 can be provided to have elastic recovery, such that the fabric wall 12 of the final patch 10 forms a snug fit over and around the busbar 11 without wrinkles.

[0035] By way of example and not limitation, when exposed to an extremely high temperature condition, such as during an unintended thermal runaway condition within one or more cells of battery pack B, the synergistic effect between layers 14, 16, and 18 causes flame-retardant multifilament yarn 18 to maintain structural integrity and inhibit the growth and spread of fire for at least five minutes or more, thereby allowing occupants of the automobile EV sufficient time to park and / or evacuate the automobile EV.

[0036] An impermeable layer 14, such as a silicone layer, a silicone-based layer, a liquid silicone rubber layer, a mica-based layer, a polytetrafluoroethylene layer, or a polyurethane layer, may be applied and adhered to the outer surface 13 of the fabric wall 12, or may be directly adhered to the outer surface 13 of the fabric wall 12. The impermeable layer 14 may be applied to the outer surface 13 using any desired process to obtain a desired thickness (t; FIG. 2A) of the impermeable layer 14. According to an exemplary embodiment, the thickness t is between about 0.05 mm and 3 mm, and more preferably between about 0.1 mm and 0.3 mm. When an impermeable layer 14 having a thickness t in the aforementioned range is provided, the flexibility and conformability of the fabric wall 12 is little or not affected (so that the flexibility and conformability of the fabric wall 12 is maintained as if the impermeable layer 14 was not adhered) and an optimal dielectric strength is provided to the patch 10, such that the breakdown voltage is between about 5 kV and 40 kV. Thus, the elongated member 11 is protected from undesirable electrical interference, including electromagnetic interference (EMI), radio frequency interference (RFI), and electrostatic discharge (ESD). In addition to various electrical protections, the inclusion of the impermeable layer 14 provides the elongated member 11 with greatly improved protection against impact forces. Furthermore, the impermeable layer 14 is hydrophobic and impermeable to fluids, gases, and solid debris, thereby providing improved protection against the ingress of contaminants such as fluids, gases, and solid debris.

[0037] The impermeable layer 14 may be provided as a liquid or powder mixture that is applied and adhered to the exterior surface 13 of the fabric wall 12. In accordance with another aspect of the present disclosure, as shown in Figures 4 and 4A, a patch or multiple patches 110 may be provided with the impermeable layer 14 as a solid sheet material that can be subsequently laminated to the exterior surface 13 of the fabric wall 12 via an intermediate flame retardant adhesive layer.

[0038] The adhesive layer 16 may be a self-adhesive layer, such as a pressure sensitive adhesive (PSA), and is configured such that the adhesive layer 16 is selectively exposed by selectively removing a release film 20 (FIGS. 2A and 2B), and the self-adhesive layer 16 adheres directly to the elongated member 11. The fabric wall 12, impermeable layer 14, and adhesive layer 16 may be of any desired shape, such as having the same or substantially the same shape as an opposing surface 15 of the busbar 11, and the adhesive layer 16 adheres to the busbar 11 to form a pre-formed patch 10 that conforms to and is fixedly attached to the busbar 11 by adhesion of the adhesive layer 16 to the busbar 11. The pre-formed patch 10 may be configured to partially or completely cover the periphery of the elongated member 11, or the pre-formed patch 10 may be a separate member and applied to a different surface of the elongated member 11, such as a separate planar surface 15, referred to as the exterior surface. To facilitate a smooth and wrinkle-free appearance, slits S may be strategically formed along opposing ends of the patch 10, 110 such that the patch 10, 110 may fold back over opposing ends of the busbar 11, including areas of bends and sharp corners, without buckling or wrinkling. Thus, one or more patches 10, 110 may be used to cover the entire circumference of the elongated member 11. A release film 20 may be attached to the adhesive layer 16 to protect the adhesive layer 16 prior to attachment to the elongated member 11, and the release film 20 is selectively removable from the adhesive layer 16 to expose the adhesive layer 16 so that the adhesive layer 16 adheres to the busbar.

[0039] According to another aspect, a method of constructing a cover 10 for providing flame-retardant, dielectric protection for a bus bar 11 interconnecting cells of a battery pack B of an electric vehicle EV includes forming a fabric wall 12 formed of a flame-retardant material, attaching an impermeable layer 14 to an outwardly facing surface of the fabric wall 12, and attaching an adhesive layer 16 to an inwardly facing surface of the fabric wall 12 such that the fabric wall 12 is sandwiched between the outwardly facing impermeable layer 14 and the inwardly facing adhesive layer 16, with the adhesive layer 16 oriented to be secured to a surface of the bus bar 11.

[0040] According to another aspect of the present disclosure, the method may further include attaching a release film 20 to the adhesive layer 16 that protects the adhesive layer 16 from damage and contamination when not in use, the release film 20 being selectively removable from the adhesive layer 16 to expose the adhesive layer 16 so that the adhesive layer 16 adheres to the bus bar 11.

[0041] According to another aspect of the present disclosure, the method may further include providing an impermeable layer 14, which is either a silicone layer, a silicone-based layer, a mica-based layer, a liquid silicone rubber layer, a polytetrafluoroethylene layer, or a polyurethane layer.

[0042] According to another aspect of the present disclosure, the method may further include forming the impermeable layer 14 from a liquid or powder mixture that is applied to the fabric wall 12.

[0043] According to another aspect of the present disclosure, the method may further include forming the impermeable layer 14 from a solid sheet material with the solid sheet material laminated to the fabric wall 12 via an intermediate flame retardant adhesive layer 19.

[0044] According to another aspect of the present disclosure, the method may further include forming the fabric wall 12 by interlacing the flame-retardant multifilament yarns with each other.

[0045] According to another aspect of the present disclosure, the method may further include providing the flame retardant multifilament yarn as a mineral yarn.

[0046] According to another aspect of the present disclosure, the method may further include providing a mineral yarn comprising at least one of a fiberglass yarn, a silica yarn, and a basalt yarn.

[0047] According to another aspect of the present disclosure, the method may further include interlacing the flame retardant multifilament yarn via a weaving, braiding or knitting process.

[0048] According to another aspect of the present disclosure, the method further includes forming the fabric wall 12 in a nonwoven process to provide the fabric wall as a nonwoven layer.

[0049] Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is contemplated that all features of all claims and all embodiments may be combined with each other, provided such combinations are not mutually inconsistent. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

Claims

1. A cover for protecting a bus bar, A fabric wall formed of a flame retardant material; an impermeable layer attached to the fabric wall; an adhesive layer attached to the fabric wall; The fabric wall is sandwiched between the impermeable layer and the adhesive layer.

2. The cover of claim 1 , wherein the fabric wall is made from interlaced flame-retardant multifilament yarns.

3. The cover of claim 2 , wherein the flame retardant multifilament yarn is a mineral yarn.

4. The cover of claim 3 , wherein the mineral yarns include at least one of fiberglass yarns, silica yarns, and basalt yarns.

5. The cover of claim 2 , wherein the interlaced yarns are one of a woven structure, a braided structure, and a knitted structure.

6. The cover of claim 1 , wherein the fabric wall is constructed as a nonwoven layer.

7. The impermeable layer is any one of a silicone layer, a silicone-based layer, a liquid silicone rubber layer, a mica-based layer, a polytetrafluoroethylene layer, and a polyurethane layer; The cover of claim 1 , wherein the impermeable layer is adhered directly to the fabric wall.

8. The impermeable layer is provided as a liquid or powder mixture; The cover of claim 1 , wherein the impermeable layer is applied to the fabric wall.

9. The cover of claim 1 , wherein the impermeable layer is a solid sheet material laminated to the fabric wall via an intermediate flame retardant adhesive layer.

10. The cover of claim 1 , wherein the adhesive layer is a self-adhesive layer configured to be exposed for adhesion to the busbar.

11. 2. The cover of claim 1, wherein the fabric wall, the impermeable layer, and the adhesive layer form a pre-formed patch configured to conform and fixedly attach to the bus bar by adhering the adhesive layer to the bus bar.

12. Further comprising a release film attached to the adhesive layer; The cover of claim 11 , wherein the release film is selectively removable from the adhesive layer to expose the adhesive layer so that the adhesive layer adheres to the bus bar.

13. A cover for protecting a bus bar that connects cells of a battery of an electric vehicle, A fabric wall formed of a flame retardant material; an impermeable layer attached to the fabric wall; an adhesive layer attached to the fabric wall; The fabric wall is sandwiched between the impermeable layer and the adhesive layer.

14. The cover of claim 13 , wherein the fabric wall is made from interlaced flame-retardant multifilament yarns.

15. 15. The cover of claim 14, wherein the interlaced flame-retardant multifilament yarns are at least one of fiberglass yarns, silica yarns, and basalt yarns.

16. The cover of claim 14 , wherein the fabric wall is woven, braided, or knitted.

17. 1. A method of constructing a cover for providing flame retardant dielectric protection to bus bars interconnecting cells of a battery in an electric vehicle, comprising: forming a fabric wall formed of a flame retardant material; attaching an impermeable layer to the fabric wall; and attaching the adhesive layer to the fabric wall such that the fabric wall is sandwiched between the adhesive layer and the impermeable layer.

18. 20. The method of claim 17, further comprising providing the impermeable layer to be one of a silicone layer, a silicone-based layer, a liquid silicone rubber layer, a mica-based layer, a polytetrafluoroethylene layer, or a polyurethane layer.

19. 20. The method of claim 17, further comprising forming the fabric wall by interlacing flame retardant multifilament yarns via any one of a weaving, braiding, and knitting process.

20. 20. The method of claim 19, further comprising providing the flame resistant multifilament yarn as a mineral yarn comprising at least one of fiberglass yarn, silica yarn, and basalt yarn.

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