A manufacturing method of a high-voltage cable in a new energy vehicle

Abstract

This invention discloses a method for manufacturing high-voltage cables for new energy vehicles, specifically including the following steps: S1. Conductor drawing; S2. Conductor stranding; S3. Insulation extrusion; S4. Braiding shielding and wrapping with aluminum-plastic composite tape; S5. Sheath extrusion; S6. Sheath irradiation. Through further improvements to the process, this invention eliminates the problems of cable arching after bending and excessive ellipticity caused by cable flattening in high-voltage cables for new energy vehicles with a diameter of 10mm² or larger after manufacturing. For models with a diameter of 6mm² or smaller, it solves the problems of low insulation concentricity and difficulty in controlling insulation adhesion.

Description

Technical Field

[0001] This invention relates to the field of cable manufacturing, and in particular to a method for manufacturing a high-voltage cable for a new energy vehicle. Background Technology

[0002] In the manufacturing process of high-voltage cables, metal conductors (such as copper rods) are usually stretched on a high-strength drawing machine to process them into metal wires. The metal wires are then processed through insulation, braiding, and sheathing to finally produce high-voltage cable equipment. All of these processes are completed in the workshop.

[0003] However, during the manufacturing process of high-voltage cables, the metal wires themselves generate certain stress when twisted into conductors after being pulled, which generally leads to the following defects:

[0004] 1. In new energy vehicles, high-voltage cables with conductors of 6mm² and below are currently using a wire harnessing process. The low roundness of the conductors leads to low concentricity of the insulation after extrusion, which affects the wire harness factory's wire cutting, increases the consumption of insulation materials, and makes it difficult to control the insulation adhesion.

[0005] 2. In new energy vehicles, the high-voltage cables with conductors of 10mm² and above are currently stranded in the same direction, which causes the cables to bend and arch. After the insulation is irradiated, the cables are flattened, affecting the wire cutting and processing by wire harness manufacturers.

[0006] 3. The cable braiding angle is unreasonable, making it difficult for the braided wires to be peeled off during wire harness processing;

[0007] Therefore, in response to the aforementioned problems that urgently need to be solved, a method for manufacturing high-voltage cables in new energy vehicles is provided here. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a method for manufacturing high-voltage cables in new energy vehicles. The main solution is to address the problem that the existing technology produces poor quality conductors with different cross-sectional areas due to the manufacturing process.

[0009] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0010] In a first aspect, this invention provides a method for manufacturing a high-voltage cable in a new energy vehicle, specifically comprising the following steps:

[0011] S1. Conductor drawing: Through conductor pulling and conductor multi-head pulling, the copper rod is drawn to the required copper wire.

[0012] S2. Conductor stranded wire, using a sizing zone extended stranding mold, and copper wire processes divided into different cross-section models; when the conductor cross-sectional area is less than the threshold, the copper wire is pressed using a layered oblique wrapping process; when the conductor cross-sectional area is greater than the threshold, a reverse structure stranded wire is constructed using a continuous pulling and unpulling conductor process.

[0013] S3. Insulation extrusion: using the conductor after the oblique wrapping in S2, the die adopts a semi-extrusion method, followed by insulation irradiation;

[0014] S4. Braiding shielding and wrapping aluminum-plastic composite tape, followed by the use of a braiding and wrapping machine to simplify the two processes of braiding shielding and wrapping aluminum-plastic composite tape of the insulated wire core into one process, while also providing braiding angle control.

[0015] Preferably, S2 also includes:

[0016] S21. Conductor threshold is 6mm 2 At and below, the stranding pitch and tension are controlled by using a servo motor-based layered skewed copper wire with a slanted wrapping device, and the stranding die in the sizing zone is used for compaction;

[0017] S22. Conductor threshold is 10mm 2 For conductors of 1000 and above, the copper wire adopts a continuous drawing and unwinding conductor process, the stranded wire adopts a reverse structure, and the stranding die in the sizing zone is used for compaction.

[0018] Preferably, in S4, the weaving angle is controlled at 55°±5°.

[0019] Preferred options also include:

[0020] S5. Sheath extrusion: The die is used to extrude the sheath using a semi-extrusion method.

[0021] S6. Sheath irradiation: The sheath is irradiated by an electron beam generated by an electron accelerator.

[0022] In a second aspect of the present invention, a high-voltage cable for a new energy vehicle is provided, manufactured according to the method of the first aspect, comprising: a conductor, the conductor being made of stranded copper wire, the conductor having a large cross-section and a small cross-section; an insulation layer, the insulation layer being disposed on the surface of the conductor, the insulation layer being attached to the surface of the conductor in an inclined manner; a braided layer, the braided layer being disposed on the surface of the insulation layer; an aluminum foil layer, the aluminum foil layer being disposed on the surface of the braided layer and being synchronously attached to the surface of the insulation layer with the braided layer; and a sheath, the sheath being disposed on the surface of the aluminum foil layer by a semi-extruded tube method.

[0023] Preferably, the conductor is made by stranding copper wire using a sizing zone lengthening stranding die, and the conductor cross-section is less than or equal to 6 mm². 2 At that time, the copper wire is inclined and layered by the sizing zone lengthening stranding mold; the conductor cross-section is greater than or equal to 10mm. 2During this time, the copper wire is continuously stretched and then wrapped in reverse between the stranding mold layers in the sizing zone.

[0024] Preferably, the inclination angle between the braided layer and the aluminum foil layer on the surface of the insulating layer is 55°±5.

[0025] Preferably, the insulating layer is inclined and covers the outer surface of the conductor in a semi-extruded manner.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] This invention, through further improvements to the manufacturing process, eliminates the problems of cable arching after bending and excessive ellipticity caused by cable flattening in high-voltage cables for new energy vehicles with a diameter of 10mm² or larger after manufacturing. For models with a diameter of 6mm² or smaller, it solves the problems of low insulation concentricity and difficulty in controlling insulation adhesion.

[0028] The present invention further constrains the braiding angle direction to facilitate the separation of braided wires from insulation during subsequent wire cutting processing in wire harness factories. Attached Figure Description

[0029] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0030] Figure 1 This is a process flow diagram of the first embodiment;

[0031] Figure 2 This is a cross-sectional view of the cable in the second embodiment;

[0032] In the diagram: 1. Conductor; 2. Insulation layer; 3. Braided layer; 4. Aluminum foil layer; 5. Sheath. Detailed Implementation

[0033] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0034] In the attached diagram, all identical reference numerals refer to the same components.

[0035] In the first embodiment, as Figure 1 As shown, this invention provides a method for manufacturing high-voltage cables in new energy vehicles, specifically including the following steps:

[0036] S1. Conductor drawing: Through conductor pulling and conductor multi-head pulling, the copper rod is drawn to the required copper wire.

[0037] The raw material, 8.0mm copper rod, is stretched using a large drawing machine to produce 1.8mm copper wire, completing the initial forming of the conductor and providing the basic wire material for subsequent fine processing.

[0038] The obtained 1.8mm copper wire is then processed into copper wire of specific specifications that meet the requirements of subsequent stranding by using a multi-head drawing equipment combined with a continuous drawing and annealing process (continuous stretching + online synchronous annealing). Because the stretching and annealing are seamlessly connected, the production efficiency is improved, and the work hardening of the copper wire is eliminated, and its conductivity and flexibility are optimized.

[0039] S2. Conductor stranded wire, using a sizing zone extended stranding die, and copper wire processes divided into different cross-section models; when the conductor cross-sectional area is small, the copper wire is pressed using a layered oblique wrapping process; when the conductor cross-sectional area is large, a reverse structure stranded wire is used using a continuous pulling and unpulling conductor process;

[0040] The specific steps are as follows:

[0041] S21. Conductor is 6mm. 2 At and below, the stranding pitch and tension are controlled by using a servo motor-driven layered skewed copper wire with a slanted wrapping device, and the stranding die with an extended sizing zone is used for compaction;

[0042] That is, at 6mm 2 When the cross-section is 1 and below, after the continuous drawing and unwinding conductor process, the oblique wrapping process is mainly adopted. The copper wire is wrapped obliquely layer by layer. Through the precise control of the servo motor, the stranding pitch is accurate, the tension control system is accurate, the conductor structure is compact and the roundness is high. The matching nano stranded wire mold with extended sizing area is used. The mold has a pressing effect, making the conductor surface smoother.

[0043] S22. Conductor is 10mm. 2 For copper wires of 1000 and above, a multi-head drawing device is used to form a continuous drawing and unwinding conductor process. The stranded wire adopts a reverse structure and is pressed tightly using a sizing zone extended stranding die.

[0044] That is, within 10mm 2 When the cross-section is 100 or above, the stranded wire adopts a reverse structure (adjacent layers are stranded in opposite directions) during the continuous pulling and unwinding conductor process. This allows the stress in the stranded wire between layers to be eliminated, making the conductor structure more stable. The conductor will not be flattened after irradiation and the cable will not bend or arch.

[0045] The copper wires are then twisted together and pressed using a sizing zone lengthening nano-stranded wire mold.

[0046] S3. Insulation extrusion: using the conductor after the oblique wrapping in S2, the die adopts a semi-extrusion method, followed by insulation irradiation;

[0047] This process uses the conductor after the oblique wrapping in step S2. Since the concentricity of the conductor can reach more than 85% at this time, the consumption of insulation material can be saved and the adhesion is easier to control. Therefore, the mold adopts a semi-extrusion tube method.

[0048] S4. Braided shielding and wrapped aluminum-plastic composite tape: The braiding and wrapping machine unit simplifies the two processes of braiding shielding and wrapping aluminum-plastic composite tape of the insulated wire core into one process, and also has braiding angle control.

[0049] In step S4, a braiding and wrapping combination unit is mainly used to simplify the two processes into one process, thereby improving production efficiency. The braiding angle is controlled at 55°±5°, which facilitates the peeling of the braided wires from the insulation layer during subsequent braiding in the wire harness factory.

[0050] S5. Sheath extrusion: The die adopts a semi-extrusion method to extrude the sheath. The die process makes it easier to control the adhesion of the sheath layer and ensure the stability of the bond between the sheath and the internal structure.

[0051] S6. Sheath irradiation: The sheath is irradiated by an electron beam generated by an electron accelerator, thereby transforming the linear molecular structure of the sheath layer into a spatial network structure, improving the heat resistance and anti-aging properties of the sheath layer, and enhancing the overall environmental adaptability of the cable.

[0052] Specifically, after the drawn copper rod is formed into copper wire, the conductor multi-head drawing method sequentially passes the copper wire through multiple precision dies to draw it into copper wire of specific specifications required for subsequent stranding. Simultaneously, low voltage and high current (using resistance heating) are applied to the drawn copper wire to raise its temperature to the recrystallization temperature of copper (250-400℃) to eliminate work hardening. After annealing, it is cooled under deionized water / nitrogen protection to prevent copper wire oxidation. This process can support the simultaneous processing of 8-24 copper wires. Finally, soft copper wire is obtained by winding. By adopting the integrated process of "drawing + annealing", the traditional two processes are integrated, and the production efficiency can be increased by more than 50%. At the same time, the internal stress of the copper wire is eliminated, ensuring its flexibility and conductivity.

[0053] For the next process, the conductor is 6mm. 2 For cross-sections of 1 and below, the copper wires drawn from multiple ends are fed into the stranding equipment, and a slanted wrapping process is adopted: the copper wires are wrapped layer by layer at an slanted angle around the center conductor to form a round stranded conductor; during the process, a nano stranding die with an extended sizing zone (smoothness Ra≤0.2μm) is used to ensure the roundness of the conductor through the die's clamping effect; the stranding pitch (10-20 times the conductor's outer diameter) and tension are monitored to avoid floating wires, which greatly improves the roundness of the conductor, providing a concentricity basis of more than 85% for subsequent insulation extrusion, and enhancing the die clamping effect, which can reduce the consumption of insulation material by 10%-15% during subsequent insulation extrusion;

[0054] The conductor is 10mm. 2 For cross-sections of 6mm and above, the copper wires that have undergone continuous drawing and unwinding are simultaneously fed into the stranding equipment, and a reverse stranding structure is used (the stranding direction of adjacent layers alternates between "right-to-left", that is, the stranding direction is opposite), and it is stranded with 6mm... 2 For cross-sections of 1 and below, the same nano-stranded wire mold with an extended sizing zone is used to monitor the stranding direction, pitch and tension, ensuring that the copper wires in each layer are subjected to uniform force, thereby eliminating internal stress in the conductor, making the conductor structure more stable, and preventing the problem of "flattening, bending and arching" after subsequent irradiation. It also improves the cleanliness and roundness of the conductor surface and completely avoids the phenomenon of floating wires and jumping strands.

[0055] Under the aforementioned conductor manufacturing scheme, during insulation extrusion, the conductor is mainly conveyed without twisting via a pay-off frame, and a semi-extrusion die is installed. The alignment accuracy between the die and the conductor is adjusted, and the high concentricity of the obliquely wrapped conductor is utilized to achieve a concentricity of over 85% for the insulation layer, thereby saving 10%-15% of insulation material. It also balances coverage and adhesion, precisely controlling the adhesion between the insulation layer and the conductor (5-10N / 10mm), which facilitates subsequent processing.

[0056] After the insulation is extruded, the semi-finished product is sent to an electron accelerator. After setting the acceleration voltage and beam current intensity, a strong electron beam is allowed to penetrate the insulation layer. The irradiation dose is controlled, and the insulation layer is transformed from a "linear molecular structure" to a "spatial network structure" through electron beam irradiation. This increases the long-term working temperature of the insulation layer to 125°C, enhances its anti-aging performance by more than 30%, and makes it suitable for the high-voltage environment inside the vehicle.

[0057] After the insulation irradiation is completed, the semi-finished product can be sent to the braiding and wrapping assembly unit. By braiding the shielding layer, the tilt angle of the braiding layer is 55°±5, ensuring the braiding density is ≥85%, and the aluminum foil layer is simultaneously wrapped around the outside of the braiding layer with an overlap rate of ≥20%. This combines the two processes of braiding and wrapping, increasing production efficiency by more than 40%. The designed braiding angle facilitates the subsequent stripping of braided wires by the wire harness factory, improving the efficiency of final processing.

[0058] The overall process is adjusted based on the original manufacturing method, so that the conductors of the high-voltage cables inside the vehicle have different processing techniques for different cross-sectional areas. For conductors with large cross-sections, the main focus is to reduce the internal stress of the conductor, making the conductor structure more stable and avoiding problems such as arching after the cable is bent or excessive ellipticity caused by the cable being flattened. For conductors with small cross-sections, the main focus is to prevent problems such as low concentricity of the conductor and difficulty in controlling the insulation adhesion. With the efficiency improvement of braided shielding + wrapping aluminum-plastic composite tape, the production capacity efficiency is increased while the quality of the produced cables is improved.

[0059] In the second embodiment, a high-voltage cable for a new energy vehicle is provided, which is manufactured according to the method described in the first embodiment and includes: a conductor 1, which is made of stranded copper wire and has a large cross-section and a small cross-section.

[0060] Insulating layer 2, the insulating layer 2 is disposed on the surface of conductor 1, the insulating layer 2 is attached to the surface of conductor 1 in an inclined manner; braided layer 3, the braided layer is disposed on the surface of insulating layer 2; aluminum foil layer 4, the aluminum foil layer 4 is disposed on the surface of braided layer, and is synchronously attached to the surface of insulating layer 2 with braided layer; sheath 5, the sheath 5 is disposed on the surface of aluminum foil layer 4 by semi-extrusion tube method.

[0061] Conductor 1 is made by stranding copper wire using a sizing zone lengthening stranding die, and the cross-section of conductor 1 is less than or equal to 6 mm². 2 At that time, the copper wire is inclined and layered by the sizing zone lengthening stranding mold; the cross-section of conductor 1 is greater than or equal to 10mm². 2 At that time, the copper wire is wrapped in reverse between the stranding mold layers in the sizing zone under continuous tension;

[0062] The cable structure is mainly divided into large cross-section and small cross-section as needed, so that the manufacturing process is different when the cross-section is different. When the cross-section is small, the copper wire is wrapped in the same direction, which makes the production efficiency of conductor 1 faster. Moreover, since the conductor 1 is used after continuous pulling and unpulling process, it does not need to be used in conjunction with multi-head pulling equipment, which makes it more convenient for the two to be used in different time sequences.

[0063] When dealing with large-section conductor 1, it is necessary to use it in conjunction with a multi-head drawing device. This allows the copper wire to be directly formed into conductor 1 while the internal stress is relatively low, i.e., before it is fully cooled. This is more conducive to the plasticity during the manufacturing process. The reverse stranding structure used ensures that the copper wire in each layer is subjected to uniform stress.

[0064] The inclination angle between the braided layer 3 and the aluminum foil layer 4 on the surface of the insulating layer 2 is 55°±5°; the insulating layer 2 is in an inclined shape and is wrapped around the outer surface of the conductor 1 in a semi-extruded manner.

[0065] This structure facilitates the subsequent stripping of braided wires by the wire harness manufacturer, improves the efficiency of the final processing, and is beneficial for the stripping of braided wires from insulation.

[0066] In summary, through further improvements to the manufacturing process, this invention eliminates the problems of cable arching and excessive ellipticity caused by cable flattening after bending in high-voltage cables of 10mm² and above in new energy vehicles. For models of 6mm² and below, it solves the problems of low insulation concentricity and difficulty in controlling insulation adhesion.

[0067] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for manufacturing a high-voltage cable for a new energy vehicle, characterized in that, Specifically, the steps include the following: S1. Conductor drawing: Through conductor pulling and conductor multi-head pulling, the copper rod is drawn to the required copper wire. S2. Conductor stranded wire, using a sizing zone extended stranding die, and setting different cross-section models of copper wire process; when the conductor cross-sectional area is less than the threshold, the copper wire is pressed using a layered oblique wrapping process; when the conductor cross-sectional area is greater than the threshold, a reverse structure stranded wire is used using a continuous pulling and unpulling conductor process; S21. Conductor threshold is 6mm 2 At and below, the stranding pitch and tension are controlled by using a servo motor-driven layered skewed copper wire with a slanted wrapping device, and the stranding die with an extended sizing zone is used for compaction. S22. Conductor threshold is 10mm 2 For conductors of 1000 and above, multi-head drawing equipment is used to form a continuous drawing and unwinding conductor process for the copper wire. The stranded wire adopts a reverse structure and is compacted using a stranding die in the sizing zone. S3. Insulation extrusion: using the conductor after the oblique wrapping in S2, the die adopts a semi-extrusion method, followed by insulation irradiation; S4. Braided shielding and wrapped aluminum-plastic composite tape: The braiding and wrapping machine simplifies the two processes of braiding the insulated wire core and wrapping the aluminum-plastic composite tape into one process, and also has braiding angle control.

2. The method for manufacturing a high-voltage cable in a new energy vehicle according to claim 1, characterized in that, In S4, the weaving angle is controlled at 55°±5°.

3. A method for manufacturing a high-voltage cable in a new energy vehicle according to claim 1 or 2, characterized in that, It also includes: S5. Sheath extrusion: The die is used to extrude the sheath using a semi-extrusion method. S6. Sheath irradiation: The sheath is irradiated by an electron beam generated by an electron accelerator.

4. A high-voltage cable for a new energy vehicle, manufactured according to the method described in claim 3, characterized in that, include: Conductor, which is made of stranded copper wires. Conductors are divided into large cross-sections and small cross-sections. When it is a large cross-section, the copper wires are wrapped in opposite directions between the layers. When the cross-section is small, the copper wire is inclined and wrapped in the same direction; An insulating layer is disposed on the surface of a conductor and is attached to the surface of the conductor in an inclined manner; A braided layer, wherein the braided layer is disposed on the surface of the insulating layer; An aluminum foil layer is disposed on the surface of the braided layer and is simultaneously bonded to the surface of the insulating layer along with the braided layer. Sheath, which is provided on the surface of aluminum foil layer by semi-extrusion tube method.

5. A high-voltage cable for a new energy vehicle according to claim 4, characterized in that, The conductor is made by stranding copper wire using a sizing zone stranding die, and the conductor cross-section is less than or equal to 6 mm². 2 At that time, the copper wire is inclined and layered through the stranding die in the sizing zone; the conductor cross-section is greater than or equal to 10 mm². 2 At this time, the copper wire is wrapped in reverse between the stranding mold layers in the sizing zone under continuous tension.

6. A high-voltage cable for a new energy vehicle according to claim 5, characterized in that, The inclination angle between the braided layer and the aluminum foil layer on the surface of the insulating layer is 55°±5.

7. A high-voltage cable for a new energy vehicle according to claim 5, characterized in that, The insulating layer is inclined and covers the outer surface of the conductor in a semi-extruded manner.

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