Self-extinguishing direct current charging cable

Abstract

The invention relates to the technical field of cables, and discloses a self-extinguishing direct-current charging cable which comprises a plurality of cable core wires twisted together and a rubber tube, the rubber tube is filled with pressurized flame-retardant liquid, a pressure sensor is mounted at a connector of the rubber tube, a sensing part of the pressure sensor extends into the rubber tube, and the pressure sensor is connected with the cable core wires. The pressure sensor is electrically connected with a switch controller, and the switch controller is electrically connected with the cable. The device can extinguish an ignition point and turn off a 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, crushing, cracking, UV, and high temperature environments. However, the cables transmit large currents and the temperature easily rises. Long-term ultra-high temperature operation causes the conductor resistance to increase, 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 solution: A self-extinguishing DC charging cable comprises a plurality of cable cores twisted together and a hose, wherein the hose is filled with pressurized flame-retardant liquid, a pressure sensor is installed at the hose interface, the sensing part of the pressure sensor extends into the hose, the pressure sensor is electrically connected to a switch controller, and the switch controller is electrically connected to the cable.

[0005] 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 arranged 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 burst by itself 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, thereby protecting the cable and charging facilities.

[0006] Optionally, it further comprises a plurality of heat-conducting strips, wherein the heat-conducting strips are twisted with the rubber tube, the heat-conducting strips are dispersed around the rubber tube, and the rubber tube and the heat-conducting strips are twisted together and then twisted with the cable core wires.

[0007] By adopting the above technical scheme, multiple heat-conducting strips are added on the basis of the original cable structure. These heat-conducting 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 contact part of the heat-conducting section. The presence of the heat-conducting strips can more effectively transfer the heat inside the cable to the hose. When the hose ruptures, it will spray out from the gap in the heat-conducting strips. The flame-retardant liquid has a certain impact and can enhance the extinguishing effect.

[0008] Optionally, the twisted tube is twisted with a shaping strip.

[0009] 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.

[0010] Optionally, the shaping strips and the heat-conducting strips are alternately arranged on the circumference of the hose, and the shaping strips have a hollow structure.

[0011] By adopting the above technical solution, the shaping strips and the heat-conducting strips are arranged alternately on the surrounding side 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, speeding up the rupture of the hose and thereby increasing the speed of fire extinguishing.

[0012] Optionally, the thermally conductive strip comprises a thermally insulating section and a thermally conductive section, the thermally conductive section and the thermally insulating section are alternately distributed, and the thermally insulating section is shorter than the thermally conductive section.

[0013] 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 smaller 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 the heat to transfer to the hose, quickly accumulate the temperature to a certain value, speed up the rupture of the hose, and thereby increase the speed of fire extinguishing.

[0014] 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.

[0015] 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.

[0016] Optionally, the length of the thermal insulation section is greater than the length of the thermal conduction section.

[0017] 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.

[0018] Optionally, the cable core includes a charging transmission core and multiple auxiliary charging cores, and multiple rubber hoses are provided, and the rubber hoses are located between the charging transmission core and the multiple auxiliary charging cores.

[0019] By adopting the above technical solution, the hose has a certain insulation 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.

[0020] Optionally, a plurality of cable cores and the hose are twisted and then wrapped with non-woven fabric.

[0021] In summary, the present application includes at least one of the following beneficial effects: 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; 2. Through the coordinated use of multiple hoses and different wire cores and the design of thermal conductive strips, when the temperature is normally high, the auxiliary charging wire core is partially insulated to reduce the heat accumulation of the auxiliary charging wire core; when the temperature is abnormally high, the thermal conductive section concentrates on absorbing heat and transferring it, accelerating the rupture of the hose, quickly responding to emergencies, increasing the speed of fire extinguishing, issuing warnings, and cutting off power in time. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the distribution of multiple cable cores and hoses in Example 1 of the present application; Figure 2 It is a schematic diagram of the structure of the rubber hose and the heat conductive strip in Example 1 of the present application; Figure 3 This is a schematic diagram of the matching structure of the hose and the heat conducting strip in Example 2 of the present application; Figure 4 Schematic diagram of the unfolded structure of the heat conducting strip and the shaping strip in Example 2 of the present application; Figure 5 It is a schematic diagram of the matching structure of the hose and the heat conducting strip in Example 3 of the present application; 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; Figure 7 This is a schematic diagram of the distribution of multiple cable cores and hoses in Example 4 of the present application.

[0023] 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

[0024] The following is combined with Figure 1 -Attached Figure 7 This application is described in further detail. Example

[0025] Example 1 of the present application discloses a self-extinguishing DC charging cable. Figure 1 The self-extinguishing DC charging cable includes a plurality of cable cores twisted together and a hose 300. Two hoses 300 are provided in this embodiment. The plurality of cable cores include a charging transmission core 100 and an auxiliary charging core 200. The charging transmission core 100 includes a charging transmission positive line 110 and a charging transmission negative line 120. The auxiliary charging core 200 includes two charging connection confirmation lines 210, two charging communication lines 220, a ground line 230, a 12V low-voltage auxiliary power positive line 240, and a 12V low-voltage auxiliary power negative line 250.

[0026] The charging and transmission positive line 110 and the charging and transmission negative line 120 use high-purity finely twisted copper wire as the conductive core 111, and the conductive core 111 is wrapped with a protective layer 112 made of a highly flame-retardant insulator TPV material. The highly flame-retardant insulator TPV material is a thermoplastic vulcanized rubber with excellent flame-retardant properties.

[0027] After twisting multiple cable cores and hoses 300, they are wrapped with corrugated non-woven fabric 10. After the non-woven fabric 10 is wrapped, Kevlar fiber is used to weave a Kevlar braided layer 20 to enhance the cable's tensile, crushing and dragging strength, with a crushing strength of ≥40N / MM. The final cable sheath 30 of the cable is made of highly flame-retardant mixed elastomer TPV material, which makes the cable resistant to oil, acid and alkali, water, wear, crushing, UV and cracking.

[0028] Specifically, the hose 300 is transparent, and the hose 300 is filled with pressurized flame retardant liquid, and the flame retardant liquid is liquid heptafluoropropane. Heptafluoropropane is gaseous at room temperature, colorless, odorless, non-conductive, non-corrosive, without environmental restrictions, and has a short atmospheric retention period. The fire extinguishing mechanism is mainly to interrupt the combustion chain, and the fire extinguishing speed is extremely fast, which is beneficial for the rescue protection of precision electronic equipment and valuables. The hose 300 is equipped with a pressure sensor (not shown in the figure), and the pressure sensor is installed at the interface of the hose 300. A sealing gasket is installed at the interface of the hose 300 to prevent the leakage of the pressurized flame retardant liquid. The pressure sensor is installed on the sealing gasket, and the sensing part of the pressure sensor extends into the hose 300 and contacts the flame retardant liquid. Finally, the pressure sensor is fixed to the interface of the hose 300 with bolts and nuts. The pressure sensor is electrically connected to a switch controller, and the switch controller is electrically connected to a cable. If the hose 300 is broken, the pressure sensor senses the pressure change in the hose 300, thereby triggering the switch controller to trip.

[0029] Furthermore, since the wall thickness of the hose 300 is relatively thin, the hose 300 is over-extended, resulting in excessive bending of the hose 300 and affecting the flow of the flame-retardant liquid.

[0030] 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 a circle or a polygon, and the cross section of the thermally conductive strips 40 in the embodiment of the present application is preferably a rectangular structure. The thermally conductive strips 40 are made of thermally conductive insulating rubber and have a certain elasticity. Before the rubber hose 300 and the plurality of cable cores are combined, the rubber hose 300 is first twisted with the plurality of thermally conductive strips 40. After the rubber hose 300 and the thermally conductive strips 40 are twisted, the thermally conductive strips 40 are dispersed around the rubber hose 300, and a gap is left between two adjacent thermally conductive strips 40. The thermally conductive strips 40 can play a certain protective and shaping role on the rubber hose 300, and the rubber hose 300 is not easily subjected to excessive extrusion during the use of the cable. In the process of twisting the rubber hose 300 and the cable core wire with each other, since the thermally conductive strips 40 are elastic, 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 rubber hose 300 and the cable core wire.

[0031] The implementation principle of the self-extinguishing DC charging cable in Example 1 of the present application is: When a short circuit or fire occurs in the cable, the cable will have a local high temperature, and the heat conductive strip 40 will transfer the temperature to the hose 300. The hose 300 will burst at the location of the short circuit and fire, and liquid HFC-227ea will spray out from the gap between the two heat conductive strips 40, which can quickly extinguish the fire. When the hose 300 breaks, 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

[0032] 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 strip 50 and the thermal conductive strip 40 are twisted together on the hose 300, and the shaping strip 50 and the thermal conductive strip 40 are staggered around the hose 300. The shaping strip 50 and the thermal conductive strip 40 are in contact with each other, and the setting of the shaping strip 50 can better shape the hose 300 and reduce the degree to which the hose 300 is squeezed. There is a hollow portion on the shaping strip 50, and the hollow portion is formed by a plurality of through holes. When the hose 300 is ruptured by heat, liquid heptafluoropropane sprays out from the hollow portion.

[0033] Reference Figure 4Furthermore, 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 position of the heat conducting strip 40, the rubber hose 300 is locally heated and burst. The heat conducting strip 40 is divided into a heat insulating section 41 and a heat conducting section 42. The heat conducting section 42 and the heat insulating section 41 are staggered, and the length of the heat insulating section 41 is shorter than that of the heat conducting section 42. The heat insulating section 41 is made of insulating rubber with a very low thermal conductivity. When the heat conducting section 42 senses the temperature, both ends of the heat conducting section 42 are heat insulating sections 41, so the temperature of the heat conducting section 42 is not easy to spread, and the heat can be conducted more quickly, which accelerates the rupture of the rubber hose 300 and accelerates the fire extinguishing effect of the cable.

[0034] 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 .

[0035] The implementation principle of the self-extinguishing DC charging cable in Example 2 of the present application is: When a short circuit or fire occurs in the cable, the cable will have a local high temperature, and the heat conductive strip 40 will transfer the temperature to the hose 300. The hose 300 will burst at the location of the short circuit and fire, and liquid HFC-227ea will be sprayed out from the hollow part of the shaping strip 50, which can quickly extinguish the fire. When the hose 300 breaks, the pressure in 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

[0036] Reference Figure 5 and Figure 6 The difference between Example 3 and Example 1 is that the structure of the heat conducting strip 40 is different. The heat conducting strip 40 has a heat insulating section 41 and a heat conducting section 42. Two adjacent heat conducting strips 40 in the circumferential direction of the rubber hose 300 are in contact with each other. Both the heat insulating section 41 and the heat conducting section 42 have hollow portions, and the hollow portions are distributed as through holes.

[0037] Reference Figure 6 , the length of the heat insulating section 41 of the heat conducting strip 40 of Example 3 is greater than the length of the heat conducting section 42, and a part of the heat insulating section 41 overlaps between two adjacent heat conducting strips 40, and the heat conducting section 42 is completely separated. The cable core wire has a contact portion with the heat conducting section 42, and when the cable core wire generates high temperature, it can be transferred to the hose 300 through the heat conducting section 42. If the hose 300 ruptures, the liquid heptafluoropropane in the hose 300 will spray out, and the pressure in the hose 300 will change sharply, and the built-in sensing device will trigger the switch to trip, thereby protecting the charging facilities and electric vehicles. Example

[0038] The difference between the fourth embodiment and the above-mentioned embodiments is that the number of the hoses 300 is greater than two, and the number of the hoses 300 in the fourth embodiment is preferably five.

[0039] Specifically, refer to Figure 7, the overall outer diameter of the charging transmission core 100 is relatively large, and 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. When the cable is charged, the temperature of the charging transmission core 100 is higher than that of the auxiliary charging core 200. The hose 300 separates the charging transmission core 100 from the multiple auxiliary charging cores 200 to reduce the mutual influence between the charging transmission core 100 and the multiple auxiliary charging cores 200.

[0040] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope 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), a sensing part 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.

2. The self-extinguishing DC charging cable according to claim 1, characterized in that: It also comprises a plurality of heat-conducting strips (40), wherein 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 wires.

3. The self-extinguishing DC charging cable according to claim 2, characterized in that: The rubber hose (300) is twisted with a shaping strip (50).

4. The self-extinguishing DC charging cable according to claim 3, characterized in that: The shaping strips (50) and the heat conducting strips (40) are arranged alternately on the circumference of the rubber hose (300), and the shaping strips (50) have a hollow structure.

5. The self-extinguishing DC charging cable according to claim 4, characterized in that: 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).

6. The self-extinguishing DC charging cable according to claim 2, characterized in that: The heat conducting strip (40) comprises a heat insulating section (41) and a heat conducting section (42), the heat insulating section (41) and the heat conducting section (42) both having a hollow structure, and in two adjacent heat conducting strips (40), the heat conducting section (42) of one heat conducting strip (40) is close to and in contact with the heat insulating section (41) of the other heat conducting strip (40).

7. The self-extinguishing DC charging cable according to claim 6, characterized in that: The length of the heat insulation section (41) is greater than the length of the heat conduction section (42).

8. The self-extinguishing DC charging cable according to claim 5 or 7, characterized in that: The cable core wire 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).

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

Images