A high-current soft charging pile fast-charging external connection cable and preparation method thereof

Abstract

The invention discloses a large-current, flexible charging pile fast-charging external connection cable and a preparation method thereof. The outer layer of fluoroplastic of the cooling tube of the main core wire plays a role of heat resistance and insulation, and the inner layer of foamed polyethylene with a foaming degree of 65-85% not only increases the volume of the coolant but also plays an effective supporting role. More importantly, when preparing the hollow flexible conductor of the main core wire, due to the improved compressive strength of the cooling tube, after all the conductor wires are grouped and bundled, the cooling tube can be used as a support and then twisted to form a wire, which can effectively increase the softness of the cable. The cable is easier to install than the cable of a conventional cooling device, has a smaller bending radius and a larger current carrying capacity; in addition, a temperature-sensitive optical fiber is added during the molding of the hollow flexible conductor, and the coolant flow rate can be controlled according to the feedback temperature to keep the cable temperature constant; the above multiple effects greatly improve the charging speed of the cable, greatly improve the heating problem of the cable, effectively reduce the insulation aging speed, increase the service life of the cable, and make the product more flexible.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicles, and in particular to a large-current flexible charging pile fast-charging external connection cable and a preparation method thereof. Background Art

[0002] With the rise of electric vehicles in the environment, the charging speed of charging piles has been initially realized from 8 hours to 1 hour fast charging, but it still cannot meet the needs of users, because the charging pile connection cable needs to be light and flexible, which limits the current of the charging cable and the high temperature and heat generated under high current conditions. At present, the charging pile cable mainly adopts the sixth category circular stranded conductor structure, which is easy to cause heat during use and reduce the current carrying capacity. In severe cases, it may cause short circuit and fire. To achieve the state of safe current carrying capacity, it is necessary to increase the wire gauge to achieve it, which not only increases weight and cost, but also wastes resources and puts a heavy burden on the charger. At present, the market urgently needs a cable with ultra-large current carrying capacity without increasing the wire gauge.

[0003] In the prior art, there are proposals to design electric vehicle charging cables with cooling tubes, such as the patent with patent number ZL201720377398.X. However, the current practice is to coat the cooling tube with a conventional conductor or twist it with a conventional conductor. However, electric vehicle charging cables have specific requirements for flexibility. Therefore, although the existing technology can achieve ultra-large current-carrying cables without increasing the wire gauge, the prepared cables are not flexible enough and are not ideal in practical applications. In addition, although the current cooling solution can alleviate the heating problem to a certain extent, the drastic changes in the cable temperature still have a certain impact on the stability of the cable operation. In short, the charging speed of existing electric vehicle charging cables is still not enough, the heating problem of the cable cannot be effectively improved, the insulation aging rate cannot be effectively reduced, and the product is not flexible enough. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a large-current flexible charging pile fast-charging external connection cable and a preparation method thereof in view of the above-mentioned defects of the prior art.

[0005] The technical solution adopted by the present invention to solve its technical problem is:

[0006] On the one hand, a method for preparing a high-current soft charging pile fast charging external connection cable is constructed, the method comprising:

[0007] A cooling tube with an outer layer of fluoroplastic and an inner layer of polyethylene with a foaming degree of 65-85% is prepared for the main core wire passing a large current;

[0008] A hollow flexible conductor is prepared for the main core wire, and a corresponding conventional stranded conductor that meets the requirements of the sixth conductor is prepared for each auxiliary core wire, wherein the preparation of the hollow flexible conductor includes: determining the number of conductor wires and the diameter of a single conductor wire according to the requirements of the sixth conductor, dividing all the conductor wires into several groups, first adding an aramid reinforcement structure to each group of conductors to form a stranded conductor in a stranding machine, and then placing the cooling tube in the center for support, using a frame stranding machine to strand all the stranded conductors and the temperature-sensitive optical fiber together to form a hollow flexible conductor wrapped around the cooling tube, the temperature-sensitive optical fiber is used to connect to the charging pile controller, and the controller is used to control the flow rate of the coolant in the cooling tube according to the temperature feedback of the temperature-sensitive optical fiber so that the feedback temperature is maintained constant;

[0009] An insulating layer is prepared outside a hollow flexible conductor to obtain a main core wire, and an insulating layer is prepared outside various conventional stranded conductors to obtain corresponding types of auxiliary core wires;

[0010] Cabling the main core wire and various auxiliary core wires to obtain a stranded cable;

[0011] A sheath covering the stranded cable is prepared.

[0012] Preferably, the preparation of the cooling tube with an outer layer of fluoroplastic and an inner layer of polyethylene with a foaming degree of 65-85% comprises: using a first extruder to extrude the outer layer of fluoroplastic, and simultaneously using a second extruder to extrude the inner layer of polyethylene with a foaming degree of 65-85%, wherein: the temperature of the first extruder is controlled at 280±10°C in the feeding section, 320±10°C in the compression section, 370±10°C in the metering section, and 385±10°C in the die head, the thickness of the fluoroplastic is controlled at 1.0±0.2mm, the outer diameter is controlled at 15±0.3mm, and the eccentricity is less than or equal to 5%; the temperature of the second extruder is controlled at 100±5°C in the feeding section, 120±5°C in the compression section, 145±5°C in the metering section, and 150±5°C in the die head, the thickness of the foamed polyethylene is controlled at 1.5±0.2mm, and the eccentricity is less than or equal to 5%.

[0013] Preferably, the wire bundling pitch ratio of the wire bundling machine when bundling is not more than 16 times the diameter of the wire conductor, and the wire stranding pitch ratio of the frame stranding machine when producing stranded wires is not more than 12 times the diameter of the hollow flexible conductor.

[0014] Preferably, cabling the main core wire and various auxiliary core wires to obtain a stranded cable comprises:

[0015] The auxiliary cores greater than one are cabled according to their corresponding numbers, and the cable pitch ratio does not exceed 16 times the cable diameter;

[0016] The cabling is made according to the prepared main core wire and auxiliary core wire according to the corresponding structure of the required cable, and filling ropes are added to fill the cabling gaps. After cabling, it is tightened with belts, and the cabling pitch ratio shall not exceed 16 times the cabling diameter.

[0017] Preferably, the various auxiliary core wires in the stranded cable include eight cabled signal wires, two cabled control wires, one ground wire and two low-voltage auxiliary power wires, and the stranded cable includes two main core wires;

[0018] The method of cabling the auxiliary core wires greater than one according to their corresponding quantities includes: selecting eight signal wires for cabling, using filling ropes for filling during cabling, wrapping the tape layer after cabling, and then wrapping the shielding layer outside the tape layer; and selecting two control wires and two filling strips for cabling, using filling ropes for filling during cabling, wrapping the tape layer after cabling, and then wrapping the shielding layer outside the tape layer, wherein the filling strips are solid structures extruded from flexible PVC.

[0019] Preferably, the eight cabled signal wires and the two cabled control wires are located on the same side of the two main core wires, the ground wire and the two low-voltage auxiliary power wires are located on the other same side of the two main core wires, and the ground wire is located between the two low-voltage auxiliary power wires.

[0020] On the other hand, a large-current flexible charging pile fast-charging external connection cable is constructed, including a sheath and a stranded cable located in the sheath, the stranded cable including a main core wire and various auxiliary core wires, the auxiliary core wire including a conventional stranded conductor that meets the requirements of the sixth conductor and an insulating layer coated on the outside of the conventional stranded conductor, the main core wire includes a cooling tube for injecting coolant, a hollow flexible conductor that meets the requirements of the sixth conductor and is wrapped around the cooling tube, and an insulating layer is coated on the outside of the hollow flexible conductor, the hollow flexible conductor is produced by placing the cooling tube in the center for support and then using a frame stranding machine to strand several strands of bundled wire conductors and temperature-sensitive optical fibers together, each strand of the bundled wire conductor is formed by adding an aramid reinforcement structure to a group of conductors and bundling them in a bundle machine, and the number of conductor wires in the hollow flexible conductor and the diameter of a single conductor wire meet the requirements of the sixth conductor, the cooling tube is a double-layer tube with an outer layer of fluoroplastic and an inner layer of polyethylene with a foaming degree of 65-85%.

[0021] Preferably, the thickness of the outer layer of fluoroplastic is 1.0±0.2 mm, and the outer diameter is 15±0.3 mm; the thickness of the inner layer of polyethylene with a foaming degree of 65-85% is 1.5±0.2 mm.

[0022] Preferably, the various auxiliary core wires in the stranded cable include a signal wire, a control wire, a ground wire and two low-voltage auxiliary power wires, and the stranded cable includes two main core wires;

[0023] The stranded cable is obtained by cabling the two main core wires, the eight cabled signal wires, the two cabled control wires, the ground wire, and the two low-voltage auxiliary power wires. The eight cabled signal wires are filled with filling ropes during cabling. The eight cabled signal wires are wrapped with a tape layer and a shielding layer in sequence. The two cabled control wires are cabled together with two filling strips and filled with filling ropes during cabling. The two cabled control wires are wrapped with a tape layer and a shielding layer in sequence.

[0024] The signal wire and the control wire in the stranded cable are located on the same side of the two main core wires, the ground wire and the two low-voltage auxiliary power wires are located on the other same side of the two main core wires, and the ground wire is located between the two low-voltage auxiliary power wires.

[0025] The high-current, flexible charging pile fast-charging external connection cable of the present invention and the preparation method thereof have the following beneficial effects: on the one hand, the outer layer of fluoroplastic in the cooling tube can play a role of heat resistance and insulation, and the inner layer of foamed polyethylene plays a supporting role. The entire cooling tube can achieve pressure resistance, temperature resistance, and insulation. Moreover, when used, the foamed polyethylene with an inner layer foaming degree of 65-85% not only increases the volume of the coolant but also plays an effective supporting role. More importantly, the improved compression resistance of the cooling tube facilitates the subsequent twisting and forming of the hollow flexible conductor. On the other hand, when preparing the hollow flexible conductor, the number of conductor wires and the diameter of a single conductor wire are determined according to the requirements of the sixth type of conductor. Since the compression resistance of the cooling tube is improved, after all the conductor wires are grouped and bundled, the cooling tube can be used as a support and then twisted to form a wire. The utility model can effectively increase the softness of the cable, and is easier to install, has a smaller bending radius and a larger current carrying capacity than the cable of the conventional cooling device; thirdly, a temperature-sensitive optical fiber is added when the hollow flexible conductor is formed, and the temperature is sensed by the temperature-sensitive optical fiber and transmitted to an externally connected controller. The controller can control the flow rate of the coolant according to the feedback temperature, so that the cable temperature is constant, and the heating temperature of the product caused by the current is reduced, so that the cable can maintain a state of ultra-large current at low temperature, and can also prevent the aging of the insulation layer, thereby achieving the effect of extending the service life; the above three aspects jointly affect each other. Under the joint action of these three aspects, the charging speed of the cable of the present invention is greatly improved, the heating problem of the cable is greatly improved, the aging speed of the insulation can be effectively reduced, thereby increasing the service life of the cable, and the product has better softness. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below. Obviously, the drawings in the following description are only embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the provided drawings without creative work:

[0027] Figure 1 It is a structural schematic diagram of the external connection cable of the high-current soft charging pile fast charging of the present invention;

[0028] Figure 2 It is a flow chart of the preparation method of the large-current flexible charging pile fast-charging external connection cable of the present invention. DETAILED DESCRIPTION

[0029] In order to facilitate understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Typical embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0031] Terms including ordinal numbers such as "first" and "second" used in this specification may be used to describe various components, but these components are not limited by these terms. The purpose of using these terms is only to distinguish one component from other components. For example, without departing from the scope of the present invention, the first component may be named as the second component, and similarly, the second component may also be named as the first component.

[0032] The general idea of ​​the present invention is: on the one hand, the cooling tube is an inner layer of polyethylene with a foaming degree of 65-85% and an outer layer of fluoroplastics, the outer layer of fluoroplastics can play a role of heat resistance and insulation, and the inner layer of foamed polyethylene plays a supporting role. The entire cooling tube can achieve pressure resistance, temperature resistance, and insulation. In addition, when used, the foamed polyethylene with a foaming degree of 65-85% in the inner layer not only increases the volume of the coolant but also plays an effective supporting role. More importantly, the improved compression resistance of the cooling tube facilitates the subsequent twisting and forming of the hollow flexible conductor; on the other hand, when preparing the hollow flexible conductor, the number of conductor wires and the diameter of a single conductor wire are determined according to the requirements of the sixth conductor. Due to the compression resistance of the cooling tube The degree of improvement is achieved, so after all the conductor wires are grouped and bundled, the cooling tube can be used as a support to form the twisted wires. This can effectively increase the softness of the cable, which is easier to install than cables with conventional cooling devices, has a smaller bending radius and a larger current carrying capacity. Thirdly, we also added temperature-sensitive optical fibers when forming the hollow flexible conductors. The temperature is sensed by the temperature-sensitive optical fibers and transmitted to an externally connected controller. The controller can control the flow rate of the coolant according to the feedback temperature, so that the cable temperature is constant, and the heating temperature of the product caused by the current is reduced, so that the cable can maintain a state of ultra-large current at low temperatures, and can also prevent the aging of the insulation layer, thereby achieving the effect of extending the service life. The above three aspects affect each other together. Under the joint action of these three aspects, the charging speed of the cable of the present invention is greatly improved, and the heating problem of the cable is greatly improved. The aging speed of the insulation can be effectively reduced to increase the service life of the cable, and the product has better softness.

[0033] In order to better understand the above-mentioned technical scheme, the above-mentioned technical scheme will be described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical scheme of the present application, rather than limitations on the technical scheme of the present application. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0034] refer to Figure 1 The high-current flexible charging pile fast-charging external connection cable of this embodiment includes a sheath 27 and a stranded cable located in the sheath 27 .

[0035] The stranded cable includes a main core wire and various auxiliary core wires. The various auxiliary core wires in the stranded cable include eight cabled signal wires, two cabled control wires, one ground wire and two low-voltage auxiliary power wires, and the stranded cable includes two main core wires. More specifically, the stranded cable is obtained by cabling two main core wires, eight cabled signal wires, two cabled control wires, a ground wire and two low-voltage auxiliary power wires. The eight cabled signal wires are filled with filling ropes 26 during cabling, and the two cabled control wires are cabled together with two filling strips 23 and filled with filling ropes 26 during cabling. The filling strips 23 are solid structures extruded from flexible PVC, and the filling ropes 26 are made of aramid material.

[0036] The two main core wires are arranged side by side, and their cross-sections together form an 8-shape. The eight signal wires and the two control wires in the stranded cable are all located on the same side of the two main core wires (such as the upper side of the 8-shape in the figure), and the ground wire and the two low-voltage auxiliary power wires are all located on the other same side of the two main core wires (such as the lower side of the 8-shape in the figure), and the ground wire is located between the two low-voltage auxiliary power wires.

[0037] The auxiliary core wire includes a conventional twisted conductor 21 that meets the requirements of the sixth type of conductor and an insulating layer 22 coated on the outside of the conventional twisted conductor 21. Specifically, the eight cabled signal wires are filled with a filling rope 26, and the eight cabled signal wires are sequentially wrapped with a tape layer 24 and a shielding layer 25. Two control wires and two filling strips 23 are cabled, and the two control wires and two filling strips 23 are filled with a filling rope 26, and after the two control wires and the two filling strips 23 are cabled, they are sequentially wrapped with a tape layer and a shielding layer 25.

[0038] The main core wire includes a cooling tube for injecting coolant, a hollow flexible conductor 14 that meets the requirements of the sixth type of conductor and wraps around the cooling tube, and an insulating layer 15 that wraps around the hollow flexible conductor 14 .

[0039] Specifically, the hollow flexible conductor 14 is produced by placing the cooling tube in the center for support and then twisting a plurality of bundled conductors and the temperature-sensitive optical fiber 13 together by a frame twisting machine. Each bundled conductor is formed by adding an aramid reinforcement structure to a group of conductors and then bundling them in a bundling machine. The number of conductor wires in the hollow flexible conductor 14 and the diameter of a single conductor wire meet the requirements of the sixth conductor. The cooling tube is obtained by using an extruder to perform double-layer co-extrusion of an outer layer of fluoroplastic 12 and an inner layer of polyethylene 11 with a foaming degree of 65-85%, that is, the cooling tube is a double-layer tube of an outer layer of fluoroplastic 12 and an inner layer of polyethylene 11 with a foaming degree of 65-85%. The thickness of the outer layer of fluoroplastic 12 is controlled at 1.0±0.2mm, and the outer diameter is controlled at 15±0.3mm; the thickness of the inner layer of polyethylene 11 with a foaming degree of 65-85% is controlled at 1.5±0.2mm.

[0040] The following introduces Figure 1 The preparation method of the external connection cable of the high-current soft charging pile fast charging is referred to Figure 2 , the method specifically includes:

[0041] S101: preparing a cooling tube with an outer layer of fluoroplastic 12 and an inner layer of polyethylene 11 with a foaming degree of 65-85% for a main core wire through which a large current passes.

[0042] For example, an extruder is used to perform double-layer co-extrusion of an outer fluoroplastic 12 and an inner polyethylene 11 with a foaming degree of 65-85%, to obtain a cooling tube with an inner polyethylene 11 with a foaming degree of 65-85% and an outer fluoroplastic 12. The outer fluoroplastic 12 can play a role in heat resistance and insulation, and the inner foamed polyethylene 11 plays a supporting role. Specifically, a first extruder is used to extrude the outer fluoroplastic 12, and the temperature of the first extruder is controlled at 280±10℃ in the feeding section, 320±10℃ in the compression section, 370±10℃ in the metering section, and 385±10℃ in the die head (specifically, the feeding section is 280℃, the compression section is 320℃, the metering section is 370℃, and the die head is 385℃ in this embodiment), the thickness of the fluoroplastic 12 is controlled at 1.0±0.2mm, the outer diameter is controlled at 15±0.3mm, and the eccentricity is less than or equal to 5%. The second extruder is used to extrude the polyethylene 11 with an inner layer foaming degree of 65-85% (70% is specifically used in this embodiment), and the temperature of the second extruder is controlled at 100±5°C in the feeding section, 120±5°C in the compression section, 145±5°C in the metering section, and 150±5°C in the die head (the feeding section is 100°C, the compression section is 120°C, the metering section is 145°C, and the die head is 150°C in this embodiment), and the thickness of the foamed polyethylene 11 is controlled at 1.5±0.2mm, and the eccentricity is less than or equal to 5%. The extrusion speed of the first extruder and the second extruder is 20 meters / min.

[0043] S102: Prepare a hollow flexible conductor 14 for the main core wire and prepare a corresponding conventional stranded conductor 21 meeting the requirements of the sixth type of conductor for each auxiliary core wire.

[0044] Among them, the auxiliary core wire is a stranded conductor generated by conductor wire and aramid reinforcement structure stranded wire, which meets the requirements of the 6th conductor in GB / T 3956.

[0045] The preparation of the hollow flexible conductor 14 includes:

[0046] 1) Determine the number of conductor wires (soft copper wires) and the diameter of a single conductor wire according to the requirements of the sixth conductor, and divide all the conductor wires into several groups;

[0047] 2) First, an aramid reinforcement structure is added to each group of conductors and the wires are bundled in a wire bundling machine to form a bundled wire conductor. The bundle pitch ratio of the wire bundling machine during the bundling process is not more than 16 times the diameter of the bundled wire conductor.

[0048] 3) Then the cooling tube is placed in the center for support, and all the bundled wire conductors and the temperature-sensitive optical fiber 13 are twisted together by a frame twisting machine to form a hollow flexible conductor 14 that wraps around the cooling tube, so that the roundness of the conductor can be effectively controlled to be no less than 10%. The pitch ratio of the twisted wire when the frame twisting machine is used for twisting is no more than 12 times the diameter of the hollow flexible conductor.

[0049] The temperature sensing optical fiber 13 is used to connect to the charging pile controller, and the controller is used to control the flow rate of the coolant in the cooling pipe according to the temperature feedback of the temperature sensing optical fiber 13 so as to maintain the feedback temperature constant. For example, the controller can be pre-set to maintain a constant temperature range for the coolant (such as 5±3℃ in winter and 15±3℃ in summer), and then the controller compares the feedback temperature with the set temperature range in real time. If the feedback temperature is lower than the set temperature range, the flow rate of the coolant in the cooling pipe is controlled to decrease; if the feedback temperature is higher than the set temperature range, the flow rate of the coolant in the cooling pipe is controlled to increase.

[0050] S103: preparing an insulating layer outside the hollow flexible conductor 14 to obtain a main core wire, and preparing an insulating layer outside various conventional twisted conductors 21 to obtain corresponding types of auxiliary core wires.

[0051] The insulation layer can be made of 125°C irradiation cross-linked polyolefin insulation. When preparing the insulation layer, an extruder is used for production, and the equipment temperature is controlled at 147±5°C in the feeding section, 156±5°C in the compression section, 160±5°C in the metering section, and 160±5°C in the die head (specifically, the feeding section is 147°C, the compression section is 156°C, the metering section is 160°C, and the die head is 160°C in this embodiment), the speed is 10 meters / min, and it is cooled in a water tank. A spark machine is used to verify the integrity of the insulation layer, and the thickness gauge and outer diameter tester are used to control the out-of-roundness and eccentricity to be ≤10%. The manufactured core wire needs to enter the irradiation equipment for irradiation, so that the linear insulation material becomes a mesh structure after irradiation, and the cross-linking of the insulation layer is increased.

[0052] S104: cabling the main core wire and various auxiliary core wires to obtain a stranded cable;

[0053] There are two steps involved:

[0054] 1) The auxiliary core wires greater than one are cabled according to their corresponding quantities, and the cable pitch ratio does not exceed 16 times the cable diameter. Specifically, it includes: selecting eight signal wires for cable production, using filling ropes 26 for filling during cabling, wrapping the tape layer 24 after cabling, and then wrapping the shielding layer 25 outside the tape layer 24; and selecting two control wires and two filling strips 23 for cable production, and using filling ropes 26 for filling during cabling, wrapping the tape layer 24 after cabling, and then wrapping the shielding layer 25 outside the tape layer 24.

[0055] The filling strip 23 is a solid structure extruded from flexible PVC, the filling rope 26 is made of aramid material, and the wrapping layer 24 is made of non-woven fabric.

[0056] 2) According to the two main core wires (a total of 2 strands), auxiliary core wires (a total of 5 strands, namely 1 ground wire, 2 low-voltage auxiliary power wires, 1 strand formed by eight cabled signal wires, and 1 strand formed by two cabled control wires), a total of 7 strands, according to the corresponding structure of the required cable (specifically, the signal line and the control line are located on the same side of the two main core wires, the ground wire and the two low-voltage auxiliary power wires are located on the other same side of the two main core wires, and the ground wire is located between the two low-voltage auxiliary power wires), the cable is made, and filling ropes 26 are added to fill the gaps in the cabling. After the cabling, it is tightened with a belt, and the cabling pitch ratio does not exceed 16 times the cabling diameter.

[0057] In the above cabling steps, the equipment used is a cabling device with full back-twisting and active pay-off, which can effectively prevent the cable from self-twisting after cabling and maintain the softness of the cable.

[0058] S105: Prepare the sheath 27 for wrapping the stranded cables.

[0059] It is produced by a sheath extruder and uses TPU material, which has excellent properties such as light weight, high softness, wear resistance, UV protection, waterproof, low temperature resistance, and corrosion resistance.

[0060] In the above embodiment, the cooling tube composed of the internal foamed polyethylene 11 and the fluoroplastic 12 plays the multiple roles of pressure resistance, facilitating the conductor twisting and molding, temperature resistance, and insulation. The temperature-sensitive optical fiber 13 can transmit the temperature of the conductor to the external controller in real time, and control the flow rate of the coolant through controller analysis to keep the conductor 14 in a constant temperature state, effectively increasing the current of the main core wire under constant temperature. Secondly, the constant temperature state can effectively prevent the aging of the insulation layer 15, thereby achieving the effect of extending the service life. The conductor 21, the insulation layer 22, the filling strip 23 and the shielding layer 25 can realize other control, grounding, induction and other functions of the charging pile. The heat-resistant and tensile-resistant aramid filling rope 26 is used to make the cable round and tensile-resistant. The lightweight non-woven fabric wrapping tape 24 is used to keep the cable structure stable. Finally, a lightweight, high-softness, wear-resistant, UV-resistant, waterproof, low-temperature-resistant and corrosion-resistant TPU sheath 27 is used for overmolding.

[0061] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A method for preparing a high-current soft charging pile fast charging external connection cable, characterized in that: The method comprises: For the main core wire that passes high current, a cooling tube with an outer layer of fluoroplastic and an inner layer of polyethylene with a foaming degree of 65-85% is prepared; A hollow flexible conductor is prepared for the main core wire, and a corresponding conventional stranded conductor that meets the requirements of the sixth conductor is prepared for each auxiliary core wire, wherein the preparation of the hollow flexible conductor includes: determining the number of conductor wires and the diameter of a single conductor wire according to the requirements of the sixth conductor, dividing all the conductor wires into several groups, first adding an aramid reinforcement structure to each group of conductors to form a stranded conductor in a stranding machine, and then placing the cooling tube in the center for support, using a frame stranding machine to strand all the stranded conductors and the temperature-sensitive optical fiber together to form a hollow flexible conductor wrapped around the cooling tube, the temperature-sensitive optical fiber is used to connect to the charging pile controller, and the controller is used to control the flow rate of the coolant in the cooling tube according to the temperature feedback of the temperature-sensitive optical fiber so that the feedback temperature is maintained constant; An insulating layer is prepared outside a hollow flexible conductor to obtain a main core wire, and an insulating layer is prepared outside various conventional stranded conductors to obtain corresponding types of auxiliary core wires; Cabling the main core wire and various auxiliary core wires to obtain a stranded cable; A sheath covering the stranded cable is prepared.

2. The method according to claim 1, characterized in that The cooling tube for preparing an outer layer of fluoroplastic and an inner layer of polyethylene with a foaming degree of 65-85% comprises: using a first extruder to extrude an outer layer of fluoroplastic, and simultaneously using a second extruder to extrude an inner layer of polyethylene with a foaming degree of 65-85%, wherein: the temperature of the first extruder is controlled at 280±10°C in the feeding section, 320±10°C in the compression section, 370±10°C in the metering section, and 385±10°C in the die head, the thickness of the fluoroplastic is controlled at 1.0±0.2mm, the outer diameter is controlled at 15±0.3mm, and the eccentricity is less than or equal to 5%; the temperature of the second extruder is controlled at 100±5°C in the feeding section, 120±5°C in the compression section, 145±5°C in the metering section, and 150±5°C in the die head, the thickness of the foamed polyethylene is controlled at 1.5±0.2mm, and the eccentricity is less than or equal to 5%.

3. The method according to claim 1, characterized in that When the wire bundling machine is used for bundling, the pitch ratio of the wires does not exceed 16 times the diameter of the wire conductor, and when the frame stranding machine is used for stranding, the pitch ratio of the stranded wires does not exceed 12 times the diameter of the hollow flexible conductor.

4. The method according to claim 1, characterized in that: The method of cabling the main core wire and various auxiliary core wires to obtain a stranded cable includes: The auxiliary cores greater than one are cabled according to their corresponding numbers, and the cable pitch ratio does not exceed 16 times the cable diameter; The cabling is made according to the prepared main core wire and auxiliary core wire according to the corresponding structure of the required cable, and filling ropes are added to fill the cabling gaps. After cabling, it is tightened with belts, and the cabling pitch ratio shall not exceed 16 times the cabling diameter.

5. The method according to claim 4, characterized in that The various auxiliary cores in the stranded cable include eight cabled signal wires, two cabled control wires, one ground wire and two low-voltage auxiliary power wires, and the stranded cable includes two main cores; The method of cabling the auxiliary core wires greater than one according to the corresponding number thereof comprises: selecting eight signal wires for cabling, using filling ropes for filling during cabling, wrapping the tape layer after cabling, and then wrapping the shielding layer outside the tape layer; Two control lines and two filling strips are selected for cable making, and filling ropes are used for filling during cabling. After cabling, a tape layer is wrapped, and then a shielding layer is wrapped outside the tape layer. The filling strip is a solid structure extruded from flexible PVC.

6. The method according to claim 5, characterized in that The eight cabled signal wires and the two cabled control wires are all located on the same side of the two main core wires, the ground wire and the two low-voltage auxiliary power wires are all located on the other same side of the two main core wires, and the ground wire is located between the two low-voltage auxiliary power wires.

7. A high current soft charging pile fast charging external connection cable, characterized in that: It comprises a sheath and a stranded cable inside the sheath, wherein the stranded cable comprises two main cores and various auxiliary cores, wherein the auxiliary cores comprise a conventional stranded conductor meeting the requirements of the sixth conductor and an insulating layer coated on the outside of the conventional stranded conductor, wherein the main core comprises a cooling tube for injecting a coolant, a hollow flexible conductor meeting the requirements of the sixth conductor and wrapped around the cooling tube, and an insulating layer coated on the outside of the hollow flexible conductor, wherein the hollow flexible conductor is produced by placing the cooling tube in the center for support and then using a frame stranding machine to strand a plurality of strands of bundled conductors and temperature-sensitive optical fibers together, wherein each strand of the bundled conductor is formed by adding an aramid reinforcement structure to a group of conductors and bundling them in a bundle machine, and the number of conductor wires in the hollow flexible conductor and the diameter of a single conductor wire meet the requirements of the sixth conductor, and the cooling tube is a double-layer tube with an outer layer of fluoroplastic and an inner layer of polyethylene with a foaming degree of 65-85%.

8. The high-current soft charging pile fast charging external connection cable according to claim 7, characterized in that: The thickness of the outer layer of fluoroplastic is 1.0±0.2mm and the outer diameter is 15±0.3mm; the thickness of the inner layer of polyethylene with a foaming degree of 65-85% is 1.5±0.2mm.

9. The high current soft charging pile fast charging external connection cable according to claim 7, characterized in that: The various auxiliary core wires in the stranded cable include a signal wire, a control wire, a ground wire and two low-voltage auxiliary power wires; The stranded cable is obtained by cabling the two main core wires, the eight cabled signal wires, the two cabled control wires, the ground wire, and the two low-voltage auxiliary power wires. The eight cabled signal wires are filled with filling ropes during cabling. The eight cabled signal wires are wrapped with a tape layer and a shielding layer in sequence. The two cabled control wires are cabled together with two filling strips and filled with filling ropes during cabling. The two cabled control wires are wrapped with a tape layer and a shielding layer in sequence. The signal wire and the control wire in the stranded cable are located on the same side of the two main core wires, the ground wire and the two low-voltage auxiliary power wires are located on the other same side of the two main core wires, and the ground wire is located between the two low-voltage auxiliary power wires.

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