Self-extinguishing DC charging cable

Abstract

This application relates to the technical field of cables and discloses a self-extinguishing DC charging cable comprising a plurality of twisted cable cores and a hose filled with a pressurized flame-retardant liquid. A pressure sensor is mounted at the hose interface, the sensing portion of the pressure sensor extending into the hose. The pressure sensor is electrically connected to a switch controller, which is electrically connected to the cable. This application can extinguish a fire and shut down the power supply.

Description

Technical Field

[0001] The present application relates to the technical field of cables, and in particular to a self-extinguishing DC charging cable. Background Art

[0002] Car charging cables must be resistant to oil, acid and alkali, water, wear, crush, crack, UV, and high temperature environments. However, the cables transmit large currents and the temperature easily rises. Long-term ultra-high temperature operation increases the conductor resistance, making short circuits or fires more likely to occur. Summary of the Invention

[0003] In order to prevent a cable with an overly high temperature from catching fire, the present application provides a self-extinguishing DC charging cable.

[0004] This application provides a self-extinguishing DC charging cable, which adopts the following technical solutions:

[0005] A self-extinguishing DC charging cable includes multiple twisted cable cores and a hose filled with pressurized flame-retardant liquid. A pressure sensor is installed at the hose interface, and the sensing portion of the pressure sensor extends into the hose. The pressure sensor is electrically connected to a switch controller, which is electrically connected to the cable.

[0006] By adopting the above technical solution, there are multiple twisted cable cores inside the self-extinguishing DC charging cable, and a hose filled with pressurized flame-retardant liquid is provided around these cores. The hose is also connected to a pressure sensor, and the pressure sensor is electrically connected to the switch controller connected to the cable. When the temperature of the cable core is too high and a short circuit or fire occurs, the temperature will be transferred to the hose, and the hose will explode at the highest temperature position, spraying out the flame-retardant liquid. The flame-retardant liquid can quickly extinguish the fire. While the flame-retardant liquid is spraying, the pressure sensor will detect the pressure change, and the pressure sensor will directly trigger the switch controller to trip, thereby protecting the cable and charging facilities.

[0007] Optionally, it further includes a plurality of heat-conducting strips, which are twisted with the hose and dispersed around the hose. The hose and the heat-conducting strips are twisted together and then twisted with the cable core wires.

[0008] By adopting the above technical solution, multiple thermally conductive strips are added to the original cable structure. These thermally conductive strips are twisted together with the hose and dispersed around the hose, which can protect and shape the hose. The circumferential direction of multiple cable cores can all contact part of the thermally conductive section. The presence of the thermally conductive strips can more effectively transfer the heat inside the cable to the hose. When the hose ruptures, it will be sprayed out from the gaps in the thermally conductive strips. The flame retardant liquid has a certain impact and can enhance the extinguishing effect.

[0009] Optionally, the twisted tube is twisted with a shaping strip.

[0010] By adopting the above technical solution, the addition of the shaping strip provides the hose with better shape retention ability, preventing the hose from being deformed or damaged due to external forces during long-term use, which helps to maintain the stability of the hose and thus extend the service life of the cable.

[0011] Optionally, the shaping strips and the heat-conducting strips are alternately arranged around the circumference of the hose, and the shaping strips have a hollow structure.

[0012] By adopting the above technical solution, the shaping strips and the heat-conducting strips are arranged alternately on the circumference of the hose, which can not only play a shaping effect but also a heat-conducting effect. The shaping strips can play an appropriate heat-insulating effect, making it difficult for the heat of the heat-conducting strips to be transferred and dispersed, so that the temperature quickly accumulates to a certain value, accelerating the speed of the hose rupture, and thereby improving the fire extinguishing speed.

[0013] Optionally, the heat conducting strip has a heat insulating section and a heat conducting section, the heat conducting section and the heat insulating section are staggered, and the length of the heat insulating section is smaller than that of the heat conducting section.

[0014] By adopting the above technical solution, the thermally conductive strip is designed to have an insulating section and a thermally conductive section, and the insulating section and the thermally conductive section are staggered. The length of the insulating section is shorter than the thermally conductive section, which means that the thermally conductive strip as a whole is still mainly heat-conducting, and heat is conducted in a local area, reducing the heat dissipation along the length of the thermally conductive strip when the thermally conductive strip receives heat, so that the thermally conductive strip can concentrate heat transfer to the hose, quickly accumulate the temperature to a certain value, accelerate the speed of the hose rupture, and thereby increase the speed of fire extinguishing.

[0015] Optionally, the thermally conductive strip has a thermal insulation section and a thermally conductive section, both of which have a hollow structure, and in two adjacent thermally conductive strips, the thermally conductive section of one thermally conductive strip is close to and in contact with the thermal insulation section of the other thermally conductive strip.

[0016] By adopting the above technical solution, the heat-conducting section can accumulate heat and reduce temperature diffusion. The hollow structure of the heat-conducting strip is mainly to facilitate the spraying of the flame-retardant liquid, and also to make the flame-retardant liquid have a certain impact force when sprayed, thereby increasing the fire extinguishing speed.

[0017] Optionally, the length of the heat insulating section is greater than the length of the heat conducting section.

[0018] By adopting the above technical solution, two adjacent heat-conducting sections are isolated by the heat-insulating section, so that the heat-conducting sections can quickly accumulate heat.

[0019] Optionally, the cable core includes a charging transmission core and multiple auxiliary charging cores, and multiple hoses are provided, and the hoses are located between the charging transmission core and the multiple auxiliary charging cores.

[0020] By adopting the above technical solution, the hose has a certain insulating effect on multiple auxiliary charging cable cores, and can more effectively manage the heat distribution inside the cable, which helps to improve the charging efficiency and safety of the cable.

[0021] Optionally, a plurality of cable cores and hoses are twisted together and then wrapped with non-woven fabric.

[0022] In summary, this application has at least one of the following beneficial effects:

[0023] 1. Through the design of pressure sensor and flame retardant liquid, the fire point can be extinguished when a fire occurs and the power supply can be disconnected when necessary to prevent the fire from happening;

[0024] 2. Through the coordinated use of multiple hoses and different cable cores, as well as the design of thermal conductive strips, the auxiliary charging cable core is partially insulated at normal high temperatures, reducing heat accumulation in the auxiliary charging cable core. When the temperature is abnormally high, the thermal conductive section concentrates heat absorption and transfer, accelerating the rupture of the hose, quickly responding to emergencies, increasing the speed of fire extinguishing, issuing warnings, and promptly cutting off power. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the distribution of multiple cable cores and hoses in Example 1 of the present application;

[0026] Figure 2 This is a schematic diagram of the structure of the hose and the thermal conductive strip in Example 1 of the present application;

[0027] Figure 3 This is a schematic diagram of the matching structure of the hose and the thermal conductive strip in Example 2 of the present application;

[0028] Figure 4 2 is a schematic diagram of the expanded structure of the heat conducting strip and the shaping strip in Example 2 of the present application;

[0029] Figure 5 This is a schematic diagram of the matching structure of the hose and the thermal conductive strip in Example 3 of the present application;

[0030] Figure 6 Schematic diagram of the distribution of the heat insulating section and the heat conducting section of two adjacent heat conducting strips in Example 3 of the present application;

[0031] Figure 7 This is a schematic diagram of the distribution of multiple cable cores and hoses in Example 4 of the present application.

[0032] Explanation of the reference numerals: 100, charging transmission line core; 110, charging transmission positive line; 120, charging transmission negative line; 111, conductive core; 112, protective layer; 200, auxiliary charging line core; 210, charging connection confirmation line; 220, charging communication line; 230, grounding line; 240, low-voltage auxiliary power supply positive line; 250, low-voltage auxiliary power supply negative line; 300, hose; 10, non-woven fabric; 20, Kevlar braided layer; 30, cable sheath; 40, thermal conductive strip; 41, thermal insulation section; 42, thermal conductive section; 50, shaping strip. DETAILED DESCRIPTION

[0033] The following is combined with Figure 1 -Attached Figure 7 This application is described in further detail. Example

[0034] Example 1 of the present application discloses a self-extinguishing DC charging cable. Figure 1 The self-extinguishing DC charging cable includes multiple twisted-together cable cores and a hose 300. In this embodiment, two hoses 300 are provided. The multiple cable cores include a charging transmission cable core 100 and an auxiliary charging cable core 200. The charging transmission cable core 100 includes a positive charging transmission cable 110 and a negative charging transmission cable 120. The auxiliary charging cable core 200 includes two charging connection confirmation cables 210, two charging communication cables 220, a ground cable 230, a 12V low-voltage auxiliary power supply positive cable 240, and a 12V low-voltage auxiliary power supply negative cable 250.

[0035] The charging and transmission positive line 110 and the charging and transmission negative line 120 use high-purity fine-twisted copper wire as the conductive core 111, and the conductive core 111 is wrapped with a protective layer 112 made of highly flame-retardant insulator TPV material. The highly flame-retardant insulator TPV material is a thermoplastic vulcanized rubber with excellent flame retardant properties.

[0036] After twisting multiple cable cores and hose 300, they are wrapped with corrugated non-woven fabric 10. After wrapping the non-woven fabric 10, Kevlar fibers are woven into a Kevlar braid 20, enhancing the cable's tensile, compression, and drag resistance. The compression strength reaches ≥40N / mm. The final cable jacket 30 is made of a highly flame-retardant, millable elastomer TPV material, making it resistant to oil, acid, alkali, water, abrasion, compression, UV rays, and cracking.

[0037] Specifically, the transparent hose 300 is filled with a pressurized flame-retardant liquid, using liquid heptafluoropropane (HFC-227ea). HFC-227ea is a gaseous substance at room temperature, colorless, odorless, non-conductive, non-corrosive, and environmentally friendly, with a short atmospheric lifetime. Its fire-extinguishing mechanism primarily interrupts the combustion chain, resulting in extremely rapid fire extinguishing, which is beneficial for emergency rescue efforts involving the protection of precision electronic equipment and valuables. The hose 300 is equipped with a pressure sensor (not shown) mounted at the interface of the hose 300. A sealing gasket is installed at the interface to prevent leakage of the pressurized flame-retardant liquid. The pressure sensor is mounted on the sealing gasket, with its sensing portion extending into the hose 300 and contacting the flame-retardant liquid. Bolts and nuts secure the pressure sensor to the interface of the hose 300. The pressure sensor is electrically connected to a switch controller, which is in turn electrically connected to a cable. If the hose 300 ruptures, the pressure sensor senses the pressure change within the hose 300, triggering the switch controller to trip the circuit breaker.

[0038] Furthermore, since the wall thickness of the hose 300 is relatively thin, the hose 300 is over-extruded, resulting in excessive bending of the hose 300 and affecting the flow of the flame-retardant liquid.

[0039] Reference Figure 2 The self-extinguishing DC charging cable also includes a plurality of thermally conductive strips 40. The cross-section of the thermally conductive strips 40 can be circular or polygonal. In the embodiment of the present application, the cross-section of the thermally conductive strips 40 is preferably a rectangular structure. The thermally conductive strips 40 are made of thermally conductive insulating rubber and have a certain degree of elasticity. Before the hose 300 and the plurality of cable cores are combined, the hose 300 is first twisted with the plurality of thermally conductive strips 40. After the hose 300 and the thermally conductive strips 40 are twisted together, the thermally conductive strips 40 are dispersed around the hose 300, with gaps left between adjacent thermally conductive strips 40. The thermally conductive strips 40 can provide a certain degree of protection and shaping for the hose 300. During the use of the cable, the hose 300 is not easily subjected to excessive extrusion. During the process of twisting the hose 300 and the cable cores, due to the elastic properties of the thermally conductive strips 40, the thermally conductive strips 40 and the highly flame-retardant insulator TPV of the charging transmission line core 100 can be squeezed and fitted, so the thermally conductive strips 40 can also increase the contact area between the hose 300 and the cable cores.

[0040] The implementation principle of the self-extinguishing DC charging cable in Example 1 of the present application is:

[0041] When a short circuit or fire occurs in the cable, the cable will have a local high temperature. The thermal conductive strip 40 transfers the temperature to the hose 300, and the hose 300 explodes at the location of the short circuit and fire. Liquid HFC-227ea sprays out from the gap between the two thermal conductive strips 40, which can quickly extinguish the fire. When the hose 300 ruptures, the pressure inside the hose 300 changes dramatically, and the built-in sensing device triggers the switch to trip, thereby protecting the charging facilities and electric vehicles. Example

[0042] Reference Figure 3 The difference between Example 2 and Example 1 is that the self-extinguishing DC charging cable also includes a plurality of shaping strips 50, and the cross-section of the shaping strip 50 is also a rectangular structure. The shaping strips 50 and the thermal conductive strips 40 are twisted together on the hose 300, and the shaping strips 50 and the thermal conductive strips 40 are staggered around the hose 300. The shaping strips 50 and the thermal conductive strips 40 are in contact with each other. The setting of the shaping strips 50 can better shape the hose 300 and reduce the degree of squeezing of the hose 300. The shaping strip 50 has a hollow portion, which is formed by a plurality of through holes. When the hose 300 is ruptured by heat, liquid heptafluoropropane is sprayed out from the hollow portion.

[0043] Reference Figure 4 Furthermore, when the heat-conducting strip 40 senses the temperature, in order to make the temperature of the heat-conducting strip 40 more concentrated at one location on the heat-conducting strip 40, the hose 300 is locally heated and burst. The heat-conducting strip 40 is divided into an insulating section 41 and a heat-conducting section 42. The heat-conducting section 42 and the heat-conducting section 41 are staggered, and the length of the heat-conducting section 41 is shorter than that of the heat-conducting section 42. The heat-conducting section 41 is made of insulating rubber with a very low thermal conductivity coefficient. When the heat-conducting section 42 senses the temperature, both ends of the heat-conducting section 42 are heat-conducting sections 41, so the temperature of the heat-conducting section 42 is not easy to spread, and heat can be conducted more quickly, accelerating the rupture of the hose 300 and accelerating the fire extinguishing effect of the cable.

[0044] In order to ensure that the heat insulating section 41 can provide heat insulation without affecting the heat conducting function of the heat conducting strip 40 , the length of the heat insulating section 41 is much smaller than that of the heat conducting section 42 .

[0045] The implementation principle of the self-extinguishing DC charging cable in Example 2 of the present application is as follows:

[0046] When a short circuit or fire occurs in the cable, the cable will have a local high temperature. The heat conductive strip 40 transfers the temperature to the hose 300, and the hose 300 explodes at the location of the short circuit and fire. Liquid HFC-227ea sprays out from the hollow part of the shaping strip 50, which can quickly extinguish the fire. When the hose 300 ruptures, the pressure inside the hose 300 changes sharply, and the built-in sensing device triggers the switch to trip, thereby protecting the charging facilities and electric vehicles. Example

[0047] Reference Figure 5 and Figure 6 The difference between Example 3 and Example 1 lies in the structure of the thermally conductive strip 40. The thermally conductive strip 40 comprises an insulating section 41 and a conductive section 42. Adjacent thermally conductive strips 40 circumferentially of the hose 300 are in contact with each other. Both the insulating section 41 and the conductive section 42 have hollow portions distributed as through holes.

[0048] Reference Figure 6In Example 3, the insulating section 41 of the thermally conductive strip 40 is longer than the conductive section 42. The insulating sections 41 of adjacent thermally conductive strips 40 partially overlap, completely separating the conductive sections 42. The cable core and the conductive sections 42 are in contact, and any high temperatures generated by the cable core are transferred through the conductive sections 42 to the hose 300. If the hose 300 ruptures, the liquid heptafluoropropane within the hose 300 will be ejected, causing a sudden change in pressure within the hose 300. This will trigger the built-in sensor to trip the switch, thereby protecting the charging facility and the electric vehicle. Example

[0049] The difference between Example 4 and the above-mentioned examples is that the number of the hoses 300 is greater than two. The number of the hoses 300 in Example 4 is preferably five.

[0050] Specifically, refer to Figure 7 The overall outer diameter of the charging transmission core 100 is relatively large, while the overall outer diameter of the auxiliary charging core 200 is relatively small. When multiple cable cores are twisted together, the five hoses 300 are located between the charging transmission core 100 and the multiple auxiliary charging cores 200. During cable charging, the temperature of the charging transmission core 100 is higher than that of the auxiliary charging core 200. The hoses 300 separate the charging transmission core 100 and the multiple auxiliary charging cores 200, reducing the mutual influence between the charging transmission core 100 and the multiple auxiliary charging cores 200.

[0051] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. Self-extinguishing DC charging cable, characterized by: The invention comprises a plurality of cable cores twisted together and a rubber hose (300), wherein the rubber hose (300) is filled with pressurized flame-retardant liquid, a pressure sensor is installed at the interface of the rubber hose (300), the sensing portion of the pressure sensor extends into the rubber hose (300), the pressure sensor is electrically connected to a switch controller, and the switch controller is electrically connected to the cable; It also includes a plurality of heat-conducting strips (40), the heat-conducting strips (40) and the rubber tube (300) are twisted together, the heat-conducting strips (40) are dispersed around the rubber tube (300), and the rubber tube (300) and the heat-conducting strips (40) are twisted together and then twisted together with the cable core wire; The rubber hose (300) is twisted with a shaping strip (50); The shaping strips (50) and the heat conducting strips (40) are arranged alternately on the circumference of the hose (300), and the shaping strips (50) have a hollow structure; The heat-conducting strip (40) comprises a heat-insulating section (41) and a heat-conducting section (42), the heat-conducting section (42) and the heat-insulating section (41) are arranged in a staggered manner, and the heat-insulating section (41) is shorter than the heat-conducting section (42); The heat-conducting section (42) is in direct contact with the cable core wire, and the heat-insulating section (41) is made of insulating rubber with a low thermal conductivity coefficient; the hollow structure of the shaping strip (50) is located in the rubber tube (300) area corresponding to the heat-conducting section (42); When the temperature of the cable core wire is too high and a short circuit or fire occurs, the temperature will be transferred to the hose (300), and the hose (300) will burst at the position with the highest temperature, spraying out the flame retardant liquid. The flame retardant liquid can quickly extinguish the fire point. While the flame retardant liquid is spraying, the pressure sensor will detect the pressure change, and the pressure sensor will directly trigger the switch controller to trip the switch, thereby protecting the cable and the charging facility.

2. The self-extinguishing DC charging cable according to claim 1, characterized in that: The cable core comprises a charging transmission core (100) and a plurality of auxiliary charging cores (200); a plurality of rubber hoses (300) are provided, and the rubber hoses (300) are located between the charging transmission core (100) and the plurality of auxiliary charging cores (200).

3. The self-extinguishing DC charging cable according to claim 1, characterized in that: A plurality of cable cores and a rubber hose (300) are twisted together and then wrapped with a non-woven fabric (10).

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