High thermal conductivity charging cable for electric vehicles

Abstract

The utility model relates to the technical field of charging cables, and specifically to a high thermal conductivity charging cable for electric vehicles, comprising: a heat-conducting pipe, the heat-conducting pipe comprising a liquid inlet pipe and a liquid outlet pipe arranged side by side, the liquid inlet pipe and the liquid outlet pipe being used for circulating a cooling medium; a power core, the power core being located on the outside of the liquid inlet pipe; a signal core, the signal core being located on the outside of the liquid outlet pipe; the power core and the signal core being twisted together on the outside of the liquid inlet pipe and the liquid outlet pipe. The utility model arranges a thermally conductive coating on the outside of a prefabricated filling strip, and the thermally conductive coating extends from the outer wall of the core to the inner side of the sheath, which is beneficial for heat to be transferred from the core to the sheath along the radial direction of the cable, and the sheath is treated with oil immersion to further increase radial thermal conductivity, and the cable has better thermal conductivity by conducting heat to the outside of the cable and the cooling effect of the cooling medium.

Description

Technical Field

[0001] The utility model relates to the technical field of charging cables, in particular to a high thermal conductivity charging cable for electric vehicles. Background Art

[0002] With the rapid development of new energy electric vehicle technology, the market and users have higher and higher expectations for the charging of automotive power batteries. Whether it is vehicle OEMs, or operators such as the State Grid and charging and swapping stations, they pay special attention to the requirements of charging safety, charging speed, charging efficiency, and charging power in the construction of charging systems and charging stations.

[0003] As the range of new energy electric vehicles continues to increase, battery capacity is also increasing. The charging system requirements have also increased from 3KW and 7KW home charging systems to 20KW, 60KW, 100KW to 120KW commercial fast charging systems. Some super charging piles even reach 320KW, which greatly improves the size of the charging gun, the safety of the charging cable, and the wire diameter.

[0004] However, the larger the wire diameter, the greater the skin effect and wire resistance, especially at the position of the charging gun head, which is at the interface of contact transmission of electrical energy with the power receiving end. The heat generated by the charging cable and the charging head is huge, and the existing technology usually dissipates heat through a water cooling system. A cooling pipeline is built into the charging cable, and the coolant pump in the charging pile circulates and dissipates heat. The cooling water circulation system circulates in the coolant tank, charging cable and charging gun of the charging pile, and the cables are connected so that the flow of coolant takes away the heat. However, the cooling pipe is usually arranged in the center of the cable core, with a small heat conduction range, and the remaining heat is not easy to dissipate. As the battery capacity increases, the charging time becomes longer and longer. Long-term transmission of large flow will make the cable heating problem more serious. Heat accumulation accelerates the aging of the cable, leading to safety risks. Utility Model Content

[0005] In view of the defects and shortcomings of the prior art, according to the first aspect of the purpose of the utility model, a charging cable for a new energy vehicle with enhanced heat dissipation is proposed, comprising:

[0006] A heat conducting pipe, the heat conducting pipe comprising a liquid inlet pipe and a liquid outlet pipe arranged side by side, the liquid inlet pipe and the liquid outlet pipe are used for circulating a cooling medium;

[0007] A power line core, the power line core is located outside the liquid inlet pipe;

[0008] A signal wire core, the signal wire core is located outside the liquid outlet pipe;

[0009] The power core and the signal core are twisted outside the liquid inlet pipe and the liquid outlet pipe, and together with the filling strips filled between the power core, the signal core, the liquid inlet pipe and the liquid outlet pipe, are wrapped and solidified into a cable core with a circular cross section;

[0010] An inner sheath, extruded on the outer wall of the wrapping layer;

[0011] An armor layer, woven on the outer wall of the inner sheath;

[0012] A braided shielding layer, covering the outer wall of the armor layer;

[0013] An outer sheath, extruded and wrapped around the outer wall of the braided shielding layer;

[0014] The outer wall of the filling strip is coated with a heat-conducting layer, the heat-conducting layer is in contact with the outer walls of the power core and the signal core, and the heat-conducting layer is in contact with the inner wall of the wrapping layer.

[0015] Preferably, the filling strip is a polyethylene foam strip.

[0016] Preferably, the heat-conducting layer includes a graphite coating or a metal powder coating, or a mixed coating of the two.

[0017] Preferably, the thickness of the heat conductive layer is greater than 100 um.

[0018] Preferably, the wrapping layer comprises a polyurethane tape or a glass ribbon soaked in insulating oil.

[0019] Preferably, the number of wrapping layers of the wrapping layer is greater than 2, and the wrapping overlap rate is greater than 45%.

[0020] Preferably, the armor layer comprises a longitudinally wrapped aluminum-plastic composite tape or a copper-plastic composite tape.

[0021] Preferably, the braided shielding layer comprises tinned braided copper wires, and the braiding density is greater than 80%.

[0022] Preferably, the inner sheath and the outer sheath comprise high thermal conductivity silicone rubber layers.

[0023] Compared with the prior art, the high thermal conductivity charging cable for electric vehicles proposed by the utility model has a thermal conductive coating arranged on the outside of the prefabricated filling strip. The thermal conductive coating extends from the outer wall of the wire core to the inner side of the winding layer, which is beneficial to the heat transfer from the wire core to the winding layer along the radial direction of the cable, and the winding layer is treated with oil immersion to further increase the radial thermal conductivity. By conducting heat to the outside of the cable and the cooling effect of the cooling medium, the thermal conductivity of the charging cable is significantly improved, the cable and the interface are quickly cooled, and the temperature rise caused by DC fast charging is alleviated. The hidden dangers to the life and safety of the cable are alleviated. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings are not intended to be drawn to scale.In the drawings, each identical or nearly identical component illustrated in various figures may be represented by a like numeral.

[0025] Figure 1 It is a structural schematic diagram of a high thermal conductivity charging cable for electric vehicles shown in the utility model.

[0026] Figure 2 It is a structural schematic diagram of the filling strip shown in the utility model. DETAILED DESCRIPTION

[0027] In order to better understand the technical content of the present invention, specific embodiments are described below in conjunction with the accompanying drawings.

[0028] At present, new energy vehicles have higher requirements for charging power, and fast charging is widely used, which can provide high-power transmission current in a short time. However, high-power transmission current will cause excessive heat. In the prior art, a cooling pipe is set in the cable core to remove heat through the flow of coolant. However, the heat transfer efficiency between the cooling pipe and the external core is low, especially in the part far away from the cooling pipe. The accumulation of heat can easily cause aging of local insulation and sheath, reduce the water blocking ability of the cable, and cause safety hazards.

[0029] The high thermal conductivity charging cable for electric vehicles of the embodiment of the utility model comprises a power core 1, a signal core 2, a heat conducting pipe 3 and a sheath structure. The heat conducting pipe 3 comprises a liquid inlet pipe 31 and a liquid outlet pipe 32 arranged side by side. The liquid inlet pipe 31 and the liquid outlet pipe 32 are used for circulating a cooling medium.

[0030] The power core 1 is located outside the liquid inlet pipe 31, and the signal core 2 is located outside the liquid outlet pipe 32. In this way, the coolant temperature of the liquid inlet pipe 31 is low, which can better dissipate heat for the signal core 2 with high heat generation.

[0031] Among them, the aforementioned power core 1 is a power transmission line, which is composed of copper conductors twisted together with an external extruded semiconductor shielding layer, a wrapped fireproof layer (mica tape) and an extruded insulation layer. The signal core 2, as a signal line, also uses copper conductors (especially tinned or nickel-plated copper conductors) twisted together with an external extruded semiconductor shielding layer and an extruded insulation shielding layer. It should be understood in particular that the wire diameter (corresponding cross-sectional area) of the signal core 2 is much smaller than the power core 1. Depending on the size of the fast charging power, the power core 1 can be selected and configured according to the power level.

[0032] The power core 1 and the signal core 2 are twisted outside the liquid inlet pipe 31 and the liquid outlet pipe 32, and together with the filling strip 4 filled between the power core 1, the signal core 2, the liquid inlet pipe 31 and the liquid outlet pipe 32, are wrapped with a sheath 5 to form a cable core with a circular cross-section.

[0033] The inner sheath 6 is extruded onto the outer wall of the wrapping layer 5 .

[0034] The armor layer 7 is woven on the outer wall of the inner sheath 6 .

[0035] The braided shielding layer 8 is coated on the outer wall of the armor layer 7 .

[0036] The outer sheath 9 is extruded around the outer wall of the braided shielding layer 8 to form a cable.

[0037] Among them, the liquid inlet pipe 31 is tangent to the liquid outlet pipe 32, and the liquid inlet pipe 31 and the liquid outlet pipe 32 are connected to the pump in the charging pile. Through the circulation of cooling medium (such as deionized water, pure water or other liquid cooling medium) in the charging pile-charging gun head-charging cable, the coolant flowing in the liquid inlet pipe 31 and the liquid outlet pipe 32 takes away the heat, suppresses and alleviates the temperature rise of the charging cable and the gun head, and improves the safety and stability of charging (that is, suppresses and reduces the charging current and power fluctuations caused by high temperature).

[0038] As an optional implementation, the power line core 1 includes a power line conductor, a power line shielding layer and a power line insulation layer, wherein the power line shielding layer and the power line insulation layer are extruded on the outer wall of the power line conductor by a double-layer co-extrusion process.

[0039] Specifically, the power line conductor is formed by twisting oxygen-free copper conductors.

[0040] Specifically, the conductor shielding layer is extruded on the outer wall of the power line conductor, has the same potential as the shielded conductor, and has good contact with the insulating layer, thereby avoiding local discharge between the conductor and the insulating layer.

[0041] Specifically, the power line insulation layer is extruded on the outer wall of the conductor shielding layer, and is made of high thermal conductivity rubber, which dissipates heat from the inside to the outside.

[0042] Furthermore, the signal wire core 2 includes a signal wire conductor, a signal wire insulation layer and a signal wire shielding layer. The signal wire insulation layer is extruded on the outer wall of the signal wire conductor, and the signal wire shielding layer is coated on the outer wall of the signal wire insulation layer.

[0043] Specifically, the signal line conductor can be an oxygen-free copper conductor, the signal line insulation layer can be a high thermal conductivity rubber, and the signal line shielding layer can be a tinned copper wire braided layer.

[0044] Furthermore, the outer wall of the filling strip 4 is coated with a heat-conducting layer 41 , and the heat-conducting layer 41 is in contact with the outer walls of the power core 1 and the signal core 2 , and the heat-conducting layer 41 is in contact with the inner wall of the wrapping layer 5 .

[0045] As an optional embodiment, the filling strip 4 includes a polyethylene foam strip, which is constructed in a prefabricated shape and can be filled between the power cores 1 and the power cores 1, between the power cores 1 and the signal cores 2, and between the signal cores 2 and the signal cores 2.

[0046] Furthermore, in order to conduct the heat of the power core 1 and the signal core 2 toward the wrapping layer 5 , the heat conducting layer 41 provides a heat transfer channel, wherein the heat conducting layer 41 includes a graphite coating or a metal powder coating.

[0047] In a specific embodiment, graphite powder or metal powder is mixed with thermosetting glue, wherein the volume proportion of the thermally conductive powder is greater than 60%.

[0048] Preferably, the thickness of the heat-conducting layer 41 is greater than 100 um, so that the heat transferred from the conductor is facilitated to be conducted along the heat-conducting layer 41 .

[0049] Preferably, the wrapping layer 5 comprises a polyurethane tape or a glass ribbon soaked in insulating oil. The polyurethane tape or the glass ribbon soaked in insulating oil can reduce the gap between the wrapping tapes and improve the thermal conductivity and water resistance.

[0050] In order to preserve the insulating oil in the wrapping layer 5, the wrapping layer 5 has more than 2 layers and a wrapping overlap ratio of more than 45%.

[0051] As an optional embodiment, the armor layer 7 includes a longitudinally wrapped aluminum-plastic composite tape or a copper-plastic composite tape. The aluminum-plastic composite tape or the copper-plastic composite tape can provide good compressive resistance while meeting the requirements of thermal conductivity.

[0052] Furthermore, a braided shielding layer 8 is disposed outside the armor layer 7. As an optional implementation, the braided shielding layer 8 includes tinned braided copper wires, and a braiding density is greater than 80%.

[0053] Preferably, the inner sheath 6 and the outer sheath 9 include a high thermal conductivity silicone rubber layer.

[0054] In combination with the above embodiments, the fast charging cable of the utility model is provided with a thermally conductive coating on the outside of the prefabricated filling strip, and the thermally conductive coating extends from the outer wall of the wire core to the inner side of the winding layer, which is beneficial to the heat transfer from the wire core to the winding layer along the radial direction of the cable, and the winding layer is treated with oil immersion to further increase the radial thermal conductivity. Combined with the conduction of heat to the outside of the cable and the circulating cooling effect of the cooling medium, the thermal conductivity of the cable is improved, the temperature rise of the charging cable and the gun head is suppressed and alleviated, and the safety and stability of charging are improved.

[0055] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A high thermal conductivity charging cable for electric vehicles, characterized in that: include: A heat conduction pipe (3), the heat conduction pipe (3) comprising a liquid inlet pipe (31) and a liquid outlet pipe (32) arranged side by side, the liquid inlet pipe (31) and the liquid outlet pipe (32) being used for circulating a cooling medium; A power line core (1), wherein the power line core (1) is located outside the liquid inlet pipe (31); A signal wire core (2), the signal wire core (2) being located outside the liquid outlet pipe (32); The power core (1) and the signal core (2) are twisted outside the liquid inlet pipe (31) and the liquid outlet pipe (32), and together with the filling strip (4) filled between the power core (1), the signal core (2), the liquid inlet pipe (31) and the liquid outlet pipe (32), are wrapped with a sheath (5) to form a cable core with a circular cross section; An inner sheath (6) extruded onto the outer wall of the wrapping layer (5); An armor layer (7) woven on the outer wall of the inner sheath (6); A braided shielding layer (8) wrapped around the outer wall of the armor layer (7); An outer sheath (9) extruded onto the outer wall of the braided shielding layer (8); The outer wall of the filling strip (4) is coated with a heat-conducting layer (41), the heat-conducting layer (41) is in contact with the outer walls of the power core (1) and the signal core (2), and the heat-conducting layer (41) is in contact with the inner wall of the wrapping layer (5).

2. The high thermal conductivity charging cable for electric vehicles according to claim 1, characterized in that: The filling strip (4) is wrapped with a polyethylene foam strip.

3. The high thermal conductivity charging cable for electric vehicles according to claim 1, characterized in that: The heat conducting layer (41) comprises a graphite coating or a metal powder coating.

4. The high thermal conductivity charging cable for electric vehicles according to claim 1, characterized in that: The thickness of the heat-conducting layer (41) is greater than 100 um.

5. The high thermal conductivity charging cable for electric vehicles according to claim 1, characterized in that: The wrapping layer (5) comprises a polyurethane tape or a glass ribbon soaked in insulating oil.

6. The high thermal conductivity charging cable for electric vehicles according to claim 1, characterized in that: The wrapping layer (5) has more than 2 wrapping layers, and a wrapping overlap ratio of more than 45%.

7. The high thermal conductivity charging cable for electric vehicles according to claim 1, characterized in that: The armor layer (7) comprises a longitudinally wrapped aluminum-plastic composite tape or a copper-plastic composite tape.

8. The high thermal conductivity charging cable for electric vehicles according to claim 1, characterized in that: The braided shielding layer (8) comprises tinned braided copper wires, and the braiding density is greater than 80%.

9. The high thermal conductivity charging cable for electric vehicles according to claim 1, characterized in that: The inner sheath (6) and the outer sheath (9) comprise a high thermal conductivity silicone rubber layer.

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