Circumferentially continuous, axially and radially stretchable, flame retardant, puncture resistant dielectric braided sleeve

Abstract

A sleeve for protecting busbars interconnecting battery cells of an electric vehicle has a woven wall having a circumferentially continuous outer surface extending along a longitudinal axis between opposite open ends. The woven wall is formed from a multifilament flame retardant yarn having a denier between 30 tex and 420 tex. The impermeable coating extends to the entire outer surface of the woven wall.

Description

[0001] Cross - reference to related applications

[0002] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 434,539, filed on December 22, 2022, and the priority of U.S. Application Serial No. 18 / 391,650, filed on December 20, 2023, the entire contents of which are incorporated herein by reference. Technical field

[0003] The present invention generally relates to a braided sleeve for protecting an elongate member received therein, and more particularly to a circumferentially continuous, axially and radially stretchable, flame - retardant, puncture - resistant dielectric braided sleeve. Background art

[0004] It is well known that enclosing various types of elongate members, such as wires, wire harnesses, cables, and conduits, in a circumferentially continuous tube wall sleeve can provide protection for the elongate members from impact and abrasion, fluids, and external heat. However, there is still a need for a protective sleeve that can provide insulation, flame - retardant, and puncture - resistant protection for the elongate member received therein, while also being able to achieve a low profile and conform to the elongate member and its connectors so as not to be cumbersome, ugly, and bulky. In addition, there is a need for a protective sleeve that can protect the bus connections between the cells of a battery pack of an electric vehicle battery system, so that when the vehicle is powered by the battery system, after thermal runaway occurs in one or more battery cells, the vehicle can still maintain its driving state for at least 5 minutes, giving the driver of the electric vehicle enough time to safely maneuver to a suitable parking position and leave the vehicle. Summary of the invention

[0005] One object of the present disclosure is to provide a stretchable braided sleeve that provides dielectric fire - extinguishing protection for an elongate member received therein.

[0006] Another object of the present disclosure is to provide protection for the bus connections between the cells of a battery pack of an electric vehicle battery system, giving the driver of the electric vehicle enough time to safely maneuver to a suitable parking position and leave the vehicle.

[0007] Another object of the present disclosure is to provide protection for the bus connections between the cells of a battery pack of an electric vehicle battery system through a braided sleeve, enabling the battery system to power the electric vehicle for 5 minutes or longer after a thermal runaway condition occurs in a cell.

[0008] Another object of the present disclosure is to provide a protective member that can be easily placed on the bus connections and connectors between the cells of a battery pack of an electric vehicle battery system.

[0009] Another object of the present disclosure is to provide a braided sleeve that can closely fit with the busbars between the cells of a battery pack of an electric vehicle battery system and can closely fit with the busbars and any connectors attached thereto.

[0010] Another object of the present disclosure is to provide a braided sleeve that can closely adhere to the busbar connection between the cells of a battery pack of an electric vehicle battery system and can withstand cracking or tearing when subjected to external force impacts.

[0011] In accordance with these and other objects, a sleeve for protecting busbars between battery cells of an electric vehicle is provided. The sleeve has a braided wall, the circumferentially continuous outer surface of which extends along a longitudinal axis between opposite open ends. The braided wall is at least partially formed of multifilament flame-retardant yarns having a denier between 30 tex and 420 tex. The braided structure of the braided wall can stretch axially and radially, so that the braided wall is easy to bend and can be easily assembled into a close-fitting, wrinkle-free relationship with the busbar, regardless of the number of bends and the shape of the outer surface profile of the busbar. A non-permeable coating extends around the outer surface of the braided wall to prevent the entry and penetration of electric dust, particulates, and smoke through the braided wall and to enhance the flame retardancy and fire resistance of the sleeve.

[0012] In accordance with another aspect of the present invention, the braided wall is entirely formed of multifilament flame-retardant yarns having a denier between 30 tex and 420 tex.

[0013] In accordance with another aspect of the present invention, the braided wall is entirely formed of multifilament flame-retardant yarns having a denier between 100 tex and 180 tex.

[0014] In accordance with another aspect of the present invention, the braided wall is entirely formed of multifilament flame-retardant yarns having a denier between 120 tex and 160 tex.

[0015] In accordance with another aspect of the present invention, the non-permeable coating is elastic and stretchable, allowing the underlying braided wall to remain stretchable, thus facilitating the formation of a wrinkle-free, close fit between the braided wall and the busbar.

[0016] In accordance with another aspect of the present invention, the non-permeable coating is one of a silicone-based, pure silicone, liquid silicone rubber, polytetrafluoroethylene, or polyurethane layer directly bonded to the outer surface of the braided wall.

[0017] In accordance with another aspect of the present invention, the thickness of the non-permeable coating is between about 0.05 mm and 4.0 mm, preferably between about 0.05 mm and 1.0 mm, and more preferably between about 0.05 mm and 0.3 mm.

[0018] In accordance with another aspect of the present invention, the multifilament flame-retardant yarns extend in a longitudinal direction generally parallel to the longitudinal axis and extend in a circumferential row direction around the longitudinal axis.

[0019] According to another aspect of the present invention, the flame-retardant yarn is a mineral yarn.

[0020] According to another aspect of the present invention, the mineral yarn can be at least one of glass fiber, silica, and basalt.

[0021] According to another aspect of the present invention, the knitted wall can be knitted using a rib knitting pattern, having raised ribs extending in at least one of the longitudinal wale direction and / or the circumferential course (filling) direction, wherein the ribs enhance flexibility, compliance, and stretchability.

[0022] According to another aspect of the present invention, the rib knitting pattern can be formed by alternately knitting stitches and purl stitches into a 1X1 pattern or a 2X2 pattern.

[0023] According to another aspect of the present invention, the size of the knitting stitches is such that there are 4 to 20 stitches per 2 cm in the transverse direction, more preferably 10 to 17 stitches per 2 cm, and 4 to 22 stitches per 2 cm in the longitudinal direction, more preferably 9 to 15 stitches per 2 cm.

[0024] According to another aspect of the present invention, the rib knitting pattern can include slip stitches to increase the height of the ribs.

[0025] According to another aspect of the present invention, there is provided a sleeve for protecting the bus bar connection between cells of a battery pack of an electric vehicle. The sleeve includes: a tubular knitted wall having a circumferentially continuous outer surface extending between opposite open ends along a longitudinal axis. The knitted wall is formed of a flame-retardant multifilament yarn having a denier between 30 tex and 420 tex, and its outermost layer has a stretchable non-permeable coating to keep the underlying knitted wall stretchable, thereby facilitating the formation of a wrinkle-free, tight fit of the knitted wall around the bus bar.

[0026] According to another aspect of the present invention, the knitted wall is composed of a multifilament flame-retardant yarn having a denier between 100 tex and 180 tex.

[0027] According to another aspect of the present invention, the knitted wall is composed of a multifilament flame-retardant yarn having a denier between 120 tex and 160 tex.

[0028] According to another aspect of the present invention, the multifilament flame-retardant yarn is composed of knitting stitches, and the stitch size is such that there are 4 to 20 stitches per 2 cm in the circumferentially extending transverse direction and 4 to 22 stitches per 2 cm in the longitudinally extending longitudinal direction.

[0029] According to another aspect of the present invention, the multifilament flame-retardant yarn is composed of knitting stitches, and the stitch size is such that there are 10 to 17 stitches per 2 cm in the circumferentially extending transverse direction and 9 to 15 stitches per 2 cm in the longitudinally extending longitudinal direction.

[0030] According to another aspect of the present invention, the non-permeable elastic coating is composed of a silicone-based coating.

[0031] According to another aspect of the present invention, a method for manufacturing a sleeve for providing dielectric protection to the busbars of batteries of interconnected electric vehicles is provided. The method includes braiding multifilament flame-retardant yarns with a denier between 30 tex and 420 tex to form a wall having a circumferentially continuous outer surface, which extends along a longitudinal axis between opposite open ends, and forming a non-permeable coating on the outer surface of the braided wall, the non-permeable coating being stretchable to allow the underlying braided wall to remain stretchable, thereby facilitating a wrinkle-free, tight fit of the braided wall with the busbar.

[0032] According to another aspect of the present invention, the method includes braiding the wall entirely with multifilament flame-retardant yarns having a denier between 100 tex and 180 tex.

[0033] According to another aspect of the present invention, the method includes braiding the wall entirely with multifilament flame-retardant yarns having a denier between 120 tex and 160 tex.

[0034] According to another aspect of the present invention, the method further includes a braiding stitch size having 4 to 20 stitches per 2 cm in the transverse direction, more preferably 10 to 17 stitches per 2 cm, and 4 to 22 stitches per 2 cm in the longitudinal direction, more preferably 9 to 15 stitches per 2 cm.

[0035] According to another aspect of the present invention, the method further includes bonding a non-permeable, elastically stretchable coating to the outer surface of the braided wall.

[0036] According to another aspect of the present invention, the method further includes bonding a non-permeable, elastically stretchable coating with a uniform thickness over the entire braided wall.

[0037] According to another aspect of the present invention, the method further includes forming a non-permeable, elastically stretchable coating with one of silicone, silicone-based, liquid silicone rubber, polytetrafluoroethylene, or polyurethane layers.

[0038] According to another aspect of the present invention, the method may further include providing the multifilament flame-retardant yarns with at least one of glass fiber, silica, and basalt. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In view of the following detailed description of presently preferred embodiments and best modes, the appended claims, and the drawings, the above and other aspects, features, and advantages will become apparent to those skilled in the art, wherein: Figure 1Perspective view of a motor vehicle having one or more braided sleeves manufactured according to one aspect of the present disclosure disposed on a battery component of an electric vehicle to be protected; Figure 2A Magnified partial schematic perspective view of a braided sleeve manufactured according to an embodiment of the present disclosure disposed on an elongate member to be protected by a textile sleeve; Figure 2B is with Figure 2A View similarly showing a sleeve manufactured according to another embodiment of the present disclosure disposed on an elongate member to be protected; Figure 2C is with Figure 2B View similarly showing a sleeve manufactured according to another embodiment of the present disclosure disposed on an elongate member to be protected; Figure 3 is a magnified schematic cross-sectional view taken generally along Figure 2A line 3-3; and Figure 4 Partial view of the wall of a sleeve manufactured according to one aspect of the present disclosure showing the braided stitches. DETAILED DESCRIPTION

[0040] Referring more particularly to the drawings, Figure 2A and Figure 3 show a textile sleeve (hereinafter referred to as sleeve 10) manufactured according to one aspect of the present invention, having an elastic textile braided wall 12 disposed around an elongate member 11 to be protected, such as a bus bar interconnecting adjacent cells of a battery pack B ( Figure 1 ), for example, of a vehicle such as an electric vehicle EV. The braided wall 12 has a circumferentially continuous outer surface 13 that longitudinally extends between open opposite ends 14, 16 and around a longitudinal central axis 18 to form a central cavity 20 through which the elongate member 11 extends. By way of example and not limitation, the elongate member 11 is protected within the central cavity 20 against impact forces such as vehicle collisions, abrasion, and ingress of contaminants. The wall 12 inhibits flame propagation, for example, in the event of thermal runaway in one or more cells of the battery pack B, thereby enabling the electric vehicle EV to remain battery powered for at least 5 minutes or more to safely drive the electric vehicle to a parked position and allow the operator to evacuate the electric vehicle EV. The flexible braided wall 12 is at least partially or entirely woven from a flame retardant, impact resistant multifilament yarn 22 ( Figure 3 ) having a denier between 30 tex and 420 tex. By way of example and not limitation, Figure 2A the braided wall 12 in Figure 4 has a generally smooth inner and outer surface along the longitudinal direction of the sleeve 10 and may be formed by any elastic braided stitch, such as by a plain knit stitch ( ).

[0041] According to another aspect, the multifilament yarn 22 of the sleeves 10', 10'' manufactured according to one aspect of the present disclosure can be knitted using a rib stitch pattern to increase the stretchability of the wall 12, thereby facilitating the assembly of the sleeve 10 with the elongating member 11 and any connectors thereon. A plurality of ribs (R) are formed by alternately knitting and purling stitches with a 1X1 or 2X2 knitting stitch pattern to form ribs R extending longitudinally (in the wale direction) ( Figure 2B as shown in the sleeve 10') and / or ribs R extending circumferentially (in the course or filling) ( Figure 2C as shown in the sleeve 10''), thereby facilitating the formation of a wrinkle-free, tight fit of the knitted wall 12 with the bus bar 11, thus facilitating assembly and suppressing flames.

[0042] Regardless of the type of knitting stitch used to knit the wall 12, the wall 12 will be knitted not thickly, and thus is very aesthetically pleasing. The knitted wall 12 can be knitted by a weft knitting process, a warp knitting process, a flat knitting machine or a circular knitting machine. In any case, the knitted structure of the knitted wall 12 is stretchable both axially and radially, so that the knitted wall is easy to bend and easy to fit tightly with the bus bar 11 and any connectors thereon.

[0043] To further enhance the flame retardant, impact resistant, puncture / tear resistant properties and resilience of the sleeves 10, 10', 10'', a tough, non-permeable elastic coating 26 is provided on the outer surface 13 of the knitted wall 12. The coating 26 further prevents dust, particles, and smoke from entering and penetrating through the knitted wall 12. The non-permeable coating 26 can be elastically stretched in all directions (including longitudinally and radially), enabling the underlying knitted wall 12 to remain stretched longitudinally and radially and have elastic resilience, thus facilitating the formation of a wrinkle-free, tight fit of the knitted wall 12 and the final sleeve 10 with the bus bar 11 and any connectors thereon.

[0044] In the event of exposure to extreme heat, such as in the case of an accidental thermal runaway within a cell of the battery pack B, the flame-retardant multifilament yarn 22 maintains its structural integrity to suppress flame growth and propagation for at least 5 minutes or longer, thereby allowing sufficient time for the occupants of the motor vehicle EV to park and / or evacuate the motor vehicle EV. According to another aspect, the wall 12 can be woven with the flame-retardant multifilament yarn 22 having a denier between 100 tex and 180 tex, and in one exemplary embodiment, is completely woven with the flame-retardant multifilament yarn 22 having a denier between 100 tex and 180 tex, and in another exemplary embodiment, is completely woven with the flame-retardant multifilament yarn 22 having a denier between 120 tex and 160 tex. To optimize the ability of the wall 12 to suppress flame propagation for 5 minutes or longer, it has been found that the designed stitch size has 4 to 20 stitches per 2 cm in the circumferential extension transverse direction, more preferably 10 to 17 stitches per 2 cm, and 4 to 22 stitches per 2 cm in the longitudinal extension longitudinal direction, more preferably 9 to 15 stitches per 2 cm.

[0045] An impermeable coating 26, such as a silicone, silicone-based, liquid silicone rubber, polytetrafluoroethylene, or polyurethane coating, can be applied and bonded to the outer surface 13, and the coating 28, also referred to as a layer, is directly bonded to the outer surface 13. The impermeable layer 26 can be applied to the outer surface 13 using any desired process to achieve the desired thickness (t) of the layer 26. In an exemplary embodiment, the thickness t is between about 0.05 and 4 mm, preferably between about 0.05 and 1.0 mm, and more preferably between about 0.1 and 0.3 mm. When the layer 26 is set within the above thickness t range, the flexibility and conformability of the wall 12 remain unchanged and can provide an optimal dielectric strength, with a dielectric breakdown voltage of about 5 to 40 kV. Thus, the elongate member 11 can be protected from unnecessary electrical interference, including electromagnetic interference (EMI), radio frequency interference (RFI), and electrostatic discharge (ESD). In addition to various electrical protections, the layer 26 can also greatly enhance the protection of the elongate member 11 against impact forces. Furthermore, since the layer 26 is hydrophobic, impervious to liquids and debris, it can also provide stronger anti-pollution protection, such as preventing the entry of fluid gases and solid debris.

[0046] According to another aspect, a method of manufacturing the sleeve 10 is provided. The method includes weaving a multifilament flame-retardant yarn having a denier between 30 tex and 420 tex to form a woven wall 12 having a circumferentially continuous outer surface 13 extending between opposite open ends 14, 16 along a longitudinal axis 18.

[0047] According to another aspect of the present invention, the method may further include knitting a multifilament flame retardant yarn using a rib stitch pattern to form a rib R that extends longitudinally along the longitudinal axis 18 of the sleeve 10, wherein the rib R enhances the flame retardancy of the wall 12 while enhancing the radial and axial extensibility of the wall 12.

[0048] According to another aspect of the present invention, the method further includes knitting the wall 12 entirely with a flame retardant multifilament yarn 22 having a denier between 100 tex and 180 tex, and in an exemplary embodiment, between 120 tex and 160 tex.

[0049] According to another aspect of the present invention, the method further includes knitting stitch sizes that have 4 to 20 stitches per 2 cm in the transverse direction, more preferably 10 to 17 stitches per 2 cm, and 4 to 22 stitches per 2 cm in the longitudinal direction, more preferably 9 to 15 stitches per 2 cm.

[0050] According to another aspect of the present invention, the method may further include bonding a non-permeable coating 26 to the outer surface 13 of the knitted wall 12, wherein the non-permeable coating 26 is formed of an elastic material to enhance the stretchability and resilience of the sleeve 10.

[0051] According to another aspect of the present invention, the method may further include forming the non-permeable coating 26 from an elastic, stretchable silicone, silicone-based, liquid silicone rubber, polytetrafluoroethylene, or polyurethane material.

[0052] Obviously, in light of the above teachings, many modifications and variations of the present invention are possible. It is contemplated that all features of all claims and all embodiments can be combined with each other as long as such combinations are not mutually inconsistent. Accordingly, it is to be understood that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described.

Claims

1. A sleeve for protecting an elongate member, comprising: A braided wall having a circumferentially continuous outer surface extending between opposite open ends along a longitudinal axis, the braided wall being formed at least in part from multifilament flame-retardant yarns having a denier between 30 tex and 420 tex; And An impermeable elastic coating extending around the outer surface of the braided wall.

2. The sleeve according to claim 1, wherein The braided wall is entirely formed from multifilament flame-retardant yarns having a denier between 30 tex and 420 tex.

3. The sleeve according to claim 2, wherein, The braided wall is entirely formed from multifilament flame-retardant yarns having a denier between 100 tex and 180 tex.

4. The sleeve according to claim 3, wherein, The braided wall is entirely formed from multifilament flame-retardant yarns having a denier between 120 tex and 160 tex.

5. The sleeve according to claim 1, wherein, The impermeable elastic coating is one of a silicone, silicone-based, liquid silicone rubber, polytetrafluoroethylene or polyurethane layer directly bonded to the outer surface.

6. The sleeve according to claim 5, wherein The thickness of the impermeable elastic coating is between about 0.05 mm and 4.0 mm.

7. The sleeve according to claim 2, wherein, The multifilament flame-retardant yarns are mineral yarns.

8. The sleeve according to claim 7, wherein, The mineral yarns are at least one of glass fiber, silica and basalt.

9. The sleeve according to claim 2, wherein, The knitting stitch size of the multifilament flame-retardant yarns is: 4 to 20 stitches per 2 cm in the circumferentially extending transverse direction and 4 to 22 stitches per 2 cm in the longitudinally extending longitudinal direction.

10. The sleeve according to claim 9, wherein, The knitting stitch size of the multifilament flame-retardant yarns is: 10 to 17 stitches per 2 cm in the circumferentially extending transverse direction and 9 to 15 stitches per 2 cm in the longitudinally extending longitudinal direction.

11. The sleeve according to claim 1, wherein, The multifilament flame-retardant yarns are knitted to form longitudinally extending ribs and / or circumferentially extending ribs.

12. The sleeve according to claim 11, wherein, Multiple ribs are formed by alternately knitting and purling stitches with each other in a desired pattern.

13. A sleeve for protecting a bus connection between cells of a battery pack of an electric vehicle, comprising: A braided wall having a circumferentially continuous outer surface extending between opposite open ends along a longitudinal axis, the braided wall being formed from multifilament flame-retardant yarns having a denier between 30 tex and 420 tex; And An impermeable elastic coating extending around the outer surface of the braided wall.

14. The sleeve according to claim 13, wherein, The braided wall is formed from multifilament flame-retardant yarns having a denier between 100 tex and 180 tex.

15. The sleeve according to claim 14, wherein, The braided wall is formed from multifilament flame-retardant yarns having a denier between 120 tex and 160 tex.

16. The sleeve according to claim 14, wherein, The knitting stitch size of the multifilament flame-retardant yarns is: 4 to 20 stitches per 2 cm in the circumferentially extending transverse direction and 4 to 22 stitches per 2 cm in the longitudinally extending longitudinal direction.

17. The sleeve according to claim 16, wherein, The knitting stitch size of the multifilament flame-retardant yarns is: 10 to 17 stitches per 2 cm in the circumferentially extending transverse direction and 9 to 15 stitches per 2 cm in the longitudinally extending longitudinal direction.

18. The sleeve according to claim 13, wherein, The impermeable elastic coating is silicone-based.

19. A method of manufacturing a sleeve for providing dielectric protection to a bus bar interconnecting cells of a battery pack of an electric vehicle, comprising: Knitting multifilament flame-retardant yarns having a denier between 30 tex and 420 tex to form a braided wall having a circumferentially continuous outer surface extending between opposite open ends along a longitudinal axis; And Bonding an impermeable elastic coating to the outer surface of the braided wall.

20. The method according to claim 19 further includes knitting the multifilament flame-retardant yarn, and the stitch size is: 4 to 20 stitches per 2 cm in the circumferentially extending transverse direction and 4 to 22 stitches per 2 cm in the longitudinally extending longitudinal direction.

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