Armored conductive member preparation method and prepared armored conductive member

Abstract

The invention discloses a preparation method of an armored conductive part and the prepared armored conductive part, and the preparation method comprises the following steps: providing a core material, and enabling the core material to be transmitted forwards; the armoring material is continuously extruded to obtain an annular armoring layer extruded material, the annular armoring layer extruded material is formed outside the core material, an armoring conductive part precursor is obtained, in the armoring conductive part precursor, the core material is suspended in the armoring layer extruded material, and a first gap is formed between the core material and the armoring layer extruded material; cooling the armored conductive part precursor to reduce the temperature of the armored layer extruded material to 0-30 DEG C to obtain a solid armored conductive part precursor; a drawing die is provided, pulling force is applied to the solid armored conductive part precursor at the outlet end of the drawing die, so that the solid armored conductive part precursor is subjected to cold drawing through the drawing die, in the cold drawing process, the outer contour size of the armored layer extrusion material is reduced, the length is increased, the thickness is basically unchanged, the first gap is shrunk into a second gap, and the armored conductive part is obtained. The production efficiency can be remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of conductive component processing technology for new energy electric vehicles, and more specifically, to a method for preparing an armored conductive component and the resulting armored conductive component. Background Technology

[0002] Conductive components account for a significant portion of the cost of high-voltage connector wiring harnesses in electric vehicles. Armored insulated conductive components refer to conductive components in which an insulating layer and an armor layer are sequentially formed outside the conductor. The insulating layer mainly serves to provide insulation protection and prevent leakage, while the armor layer mainly serves to provide electromagnetic shielding and prevent electromagnetic radiation leakage.

[0003] In existing technology, one method for preparing the armor layer involves separately preparing an armor sleeve and an insulating conductive component covered with an insulating layer. The armor sleeve is then fitted over the insulating conductive component, and a pulling device is used to reduce the diameter of the armor sleeve, eliminating the gap between the armor sleeve and the insulating conductive component, thus obtaining the armored insulating conductive component. The disadvantages of this method are: first, axial friction marks are easily left on the surface of the armor layer, which does not meet the product appearance quality requirements; second, the armor sleeve and the insulating conductive component are prepared separately, and the pulling process to ensure the armor layer adheres tightly to the insulating layer also needs to be performed separately. The entire preparation process cannot achieve continuous production, resulting in low production efficiency and high costs.

[0004] In existing technologies, another method for preparing the armor layer is a combination of continuous extrusion and hot shrinking. This involves cooling the high-temperature armor layer after continuous extrusion, but not completely cooling it. While the extruded material is still semi-molten, it is then hot-shrinked using a shrinking die. Although this technology allows for continuous production and avoids friction marks, the shrinking die still extrudes semi-molten material. The power for the shrinking die still comes from the forward thrust of the continuous extruder, effectively lengthening the extrusion channel of the continuous extruder's die. A longer extrusion channel increases the difficulty of extrusion and slows the extrusion speed, resulting in a slower overall production speed for the continuous production line. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned defects in the prior art and provide a method for preparing an armored conductive component and the resulting armored conductive component. By using a continuous extrusion method, a smooth armor layer is not only formed on the outside of the core material, but the speed of continuous production is also improved.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: A method for preparing an armored conductive component includes the following steps: Provide the core material to enable its forward transport; The armor material is continuously extruded to obtain an annular armor layer extrusion, which is formed outside the core material to obtain an armor conductive component precursor. In the armor conductive component precursor, the core material is suspended in the armor layer extrusion, and a first gap is provided between the core material and the armor layer extrusion. The armored conductive component precursor is cooled to reduce the temperature of the extruded armor layer to 0°C~30°C to obtain a solid armored conductive component precursor. A drawing die is provided, and a tensile force is applied to the solid armored conductive component precursor at the exit end of the drawing die, so that the solid armored conductive component precursor is cold drawn through the drawing die. During the cold drawing process, the volume mass conservation and non-section mass conservation are observed. The outer contour dimension of the armor layer extrusion material becomes smaller, the length of the armor layer extrusion material becomes longer, the thickness of the armor layer extrusion material remains basically unchanged, and the first gap is reduced to a second gap, thereby obtaining the armored conductive component.

[0007] The present invention also provides an armored conductive component prepared by the above-described method.

[0008] The implementation of the present invention will have the following beneficial effects: In this embodiment of the invention, during the continuous extrusion preparation of the armor layer extrusion material, a safe distance of a first gap is maintained between the high-temperature armor layer extrusion material and the core material to avoid burning the insulation layer. Then, the temperature of the armor layer extrusion material is cooled down to 0℃~30℃, allowing it to completely cool into a solid state. This gives the armor layer a certain strength, enabling it to withstand tensile stress and pass through the drawing die. Furthermore, the armor layer of this invention undergoes only a rapid temperature drop before entering the drawing die, without aging treatment. The solid armor layer at this stage has better plasticity than an aged armor layer, making it easier to reduce its diameter. Compared to existing technologies where the armor layer sleeve and insulating conductive component are prepared separately, the armor layer sleeve is typically made of aged metal, resulting in a more stable structure, greater hardness, and avoiding large friction marks on the armor layer surface.

[0009] Meanwhile, the method of combining extrusion and cold drawing in this invention can avoid increasing the extrusion difficulty of the armor layer extruded material and improve the production speed of continuous production lines. Attached Figure Description

[0010] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0011] in: Figure 1 This is a schematic flowchart illustrating a method for preparing an armored conductive component according to a specific embodiment of the present invention.

[0012] Figure 2 This is a schematic flowchart of a device for preparing an armored conductive component according to a specific embodiment of the present invention.

[0013] Figure 3 yes Figure 2 A schematic diagram of the cross-sectional structure of the extrusion die in a continuous extrusion coating mechanism. Detailed Implementation

[0014] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0015] This invention discloses a method for preparing an armored conductive component, comprising the following steps: S1: Provides the core material, enabling it to be transported forward.

[0016] The core material can be a single-layer material or a multi-layer material with two or more layers. For example, in one embodiment, the core material is a metal conductor core, specifically, it can be a pure aluminum, aluminum alloy, pure copper, copper alloy, copper-clad aluminum, aluminum-clad copper, etc. The structure and material of the metal conductor core are not limited to the above-listed examples.

[0017] In another embodiment, the core material is a composite core material with an insulating layer, for example, an insulating layer is wrapped around the metal conductor core listed above. The method of the present invention is particularly suitable for forming an armor layer on the outside of the composite core material with an insulating layer, avoiding the burning of the insulating layer by the high-temperature semi-molten material extruded continuously.

[0018] S2: The armor material is continuously extruded to obtain an annular armor layer extrusion, which is formed outside the core material to obtain the armor conductive component precursor. In the armor conductive component precursor, the core material is suspended in the armor layer extrusion, and a first gap is provided between the core material and the armor layer extrusion.

[0019] In this invention, reference Figure 2Continuous extrusion is carried out in a continuous extrusion coating mechanism 1, which includes a continuous extruder and an extrusion die 11. The continuous extruder includes an extrusion roller and an extrusion roller shoe. The extrusion roller has an extrusion roller groove, and the extrusion roller and extrusion roller shoe form an extrusion cavity. The extrusion roller shoe has a die orifice, and the extrusion roller shoe is connected to the extrusion die 11. Continuous extrusion involves feeding armor material to the extrusion roller, which carries the armor material into the extrusion cavity formed by the extrusion roller and extrusion roller shoe. The continuous rotation of the extrusion roller continuously rubs and extrudes the armor material, causing the armor material to heat up and soften to obtain armor extruded material. The armor extruded material is then extruded through the extrusion die to form an armor layer. The continuous extrusion method of the present invention can obtain a continuous and uninterrupted extruded material as long as the armor material is continuously fed to the extrusion roller, which can significantly improve production efficiency.

[0020] In this invention, reference Figure 3 The extrusion die includes a core 111 and an outer die 112 axially sleeved outside the core 111. An annular extrusion cavity 113 is provided between the outer die 112 and the core 111. The core 111 is provided with an axial through hole 114. The extrusion die 11 is connected to the extrusion roller shoe. After the armor extrusion material is formed in the extrusion cavity, it enters the annular extrusion cavity 113 of the extrusion die 11 to form an annular armor layer extrusion material.

[0021] The armor extrusion material is extruded from the annular extrusion chamber 113 to form an annular armor layer extrusion material. The core material passes through the through hole 114 and enters the formed armor layer extrusion material to obtain the armor conductive component precursor. In the armor conductive component precursor, the core material is suspended in the armor layer extrusion material, and a first gap is provided between the core material and the armor layer extrusion material.

[0022] In this invention, the core material is continuously fed forward, while the armor extrusion material is continuously extruded to wrap around the core material at a distance of a first gap. As the core material continues to be fed forward, the armor layer is simultaneously formed on the outside of the core material. Therefore, as long as the core material is continuously fed forward and the armor layer is continuously formed on the outside of the core material, the armored conductive component precursor can be continuously produced.

[0023] S3: Cool the armored conductive component precursor to reduce the temperature of the armored layer extrusion material to 0℃~30℃ to obtain a solid armored conductive component precursor.

[0024] In this step, the purpose of cooling is to completely cool the armor layer to a solid state, thereby increasing the strength of the armor layer. This allows it to withstand the tensile force applied to the armor layer at the exit end of the drawing die and be drawn through the drawing die. Furthermore, compared to the aged armor layer, it has better plasticity and is easier to reduce in diameter.

[0025] Cooling can be any one or a combination of two or more of the following methods: air cooling, circulating coolant cooling, air cooling, or liquid nitrogen cooling.

[0026] S4: Provide a drawing die, apply tension to the solid armored conductive component precursor at the exit end of the drawing die, so that the solid armored conductive component precursor is cold drawn through the drawing die. During the cold drawing process, the volume mass conservation and non-section mass conservation are observed. The outer contour dimension of the armor layer extrusion becomes smaller, the length of the armor layer extrusion becomes longer, the thickness of the armor layer extrusion remains basically unchanged, the first gap is reduced to the second gap, and the armored conductive component is obtained.

[0027] In the cold drawing process of this invention, since tensile force is applied to draw the solid armored conductive component precursor through the drawing die, the plastic deformation mainly occurs by the reduction of the outer contour size of the armor layer extrusion and the increase of the length of the armor layer extrusion. The thickness of the armor layer extrusion remains basically unchanged. Here, the thickness of the armor layer extrusion remains basically unchanged means that the slight change in thickness is within the allowable tolerance range of the final product size. In the design, the thickness of the annular armor layer extrusion obtained by continuous extrusion can be directly designed as the armor layer thickness of the final product, or only a slight adjustment can be made.

[0028] In this invention, since a solid armor layer is being drawn, the reduction in the outer contour dimensions of the armor layer extrusion cannot be converted into an increase in thickness.

[0029] In this invention, the transmission speed of the core material is mainly provided by the tension at the exit end of the drawing die. Before passing through the drawing die, the speed of the armor layer extrusion is mainly provided by the extrusion speed of the continuous extruder. After passing through the drawing die, the speed of the armor layer is mainly provided by the tension. Since the armor layer is in close contact or basically in close contact with the insulation layer after the drawing die, the speed of the armor layer after the drawing die is equal to the transmission speed of the core material. The traction mechanism simultaneously tractions the armor layer and the core material.

[0030] In this invention, the continuous extrusion of the armor layer extrusion material and the diameter reduction of the drawing die are carried out online simultaneously. Therefore, the extrusion speed of the armor layer extrusion material and the transmission speed of the core material need to be matched.

[0031] According to the law of conservation of volume and mass, the volume of the armor layer extruded material entering the drawing die per unit time is equal to the volume of the armor layer extruded material exiting the drawing die per unit time. Since the core material dimensions do not change before and after diameter reduction, the ratio of the armor layer's entry and exit speeds from the drawing die is equal to the inverse ratio of the armor layer's cross-sectional area. The speed of the armor layer exiting the drawing die is equal to the core material's transport speed. Therefore, the following core material transport speed can be derived. Extrusion speed of the armor layer extruded material Relationship: In the above formula, The thickness of the armor layer, The inner diameter of the armor layer before drawing. The inner diameter after the armor layer is drawn. The outer diameter of the armor layer before drawing. The outer diameter after the armor layer is drawn.

[0032] In a preferred embodiment, the cold drawing process involves multiple drawing passes through two or more drawing dies. This not only reduces the amount of deformation per pass, reduces surface scratches or cracks, and improves surface smoothness, but also facilitates the preparation of irregular armor layer structures. By gradually correcting local deformation errors, the dimensional control accuracy of irregular structure corners, grooves, and other areas is improved, thereby improving the overall dimensional accuracy of the product's outer contour.

[0033] In one specific embodiment, the drawing die is provided with a drawing cavity, which includes a variable diameter section and a fixed diameter section connected in sequence. The inner diameter of the variable diameter section gradually decreases along the drawing direction, while the inner diameter of the fixed diameter section remains unchanged along the drawing direction. The main function of the variable diameter section is to provide extrusion pressure to reduce the outer diameter, while the main function of the fixed diameter section is to shape the outer contour dimensions of the armor layer and to smooth the outer surface of the armor layer.

[0034] A tensile force is applied to the armor layer and core material from the exit end of the drawing die. The formula for calculating the tensile force applied to the armor layer and core material as they pass through the drawing die is as follows: In the above formula, For tension, For the deformation resistance of the armor layer, For the armor layer in the first Friction in a drawing die For the number of drawing dies, The extrusion force of the armor layer extruded material. For the flow stress of the armor layer, This refers to the cross-sectional area of ​​the armor layer after its diameter reduction. This refers to the cross-sectional area of ​​the armor layer before diameter reduction. The coefficient of friction, For the first The die angle of the variable diameter section of a drawing die. For the first The length of the sizing section of a drawing die. For the first The inner diameter of the outlet of a drawing die. For the first The average inner diameter of each drawing die.

[0035] In a preferred embodiment, the elongation factor of each pass in the multi-pass drawing is less than 1.3, and the die angle of each drawing die in the multi-pass drawing is 5°~15° to prevent the armor layer from being torn apart. The elongation factor is the ratio of the cross-sectional area before drawing to the cross-sectional area after drawing. The die angle is the angle between the inner surface of the diameter-changing section of the drawing die and the central axis of the drawing die.

[0036] Preferably, the die angles of each drawing die gradually decrease along the drawing direction, that is, the die angles of the drawing dies become smaller as they go further. This results in smaller extrusion deformation, making it easier to correct local deformation errors and improve the dimensional control accuracy of irregular structure corners, grooves, and other areas, thereby improving the overall dimensional accuracy of the product's outer contour.

[0037] Preferably, in one specific embodiment, the die angle of the first drawing die along the drawing direction is 5° to 15°, and the die angle of each subsequent drawing die is reduced by 0° to 3° compared to the previous one, preferably by 1° to 3°.

[0038] Preferably, the length of the sizing section of each drawing die gradually decreases along the drawing direction to gradually reduce frictional resistance. Specifically, in one embodiment, the length of the sizing section of the first drawing die is 3mm to 16mm, and the length of the sizing section of the last drawing die is 1mm to 8mm.

[0039] Preferably, the size of the second gap is less than 1 mm, and the size of the first gap is 0.5 mm to 10 mm. The main function of the first gap is to provide a safety distance to prevent the high-temperature extruded material from burning the insulation layer. The main function of the second gap is to provide a safety distance for subsequent bending of the armored conductive parts to prevent damage to the insulation layer at the bending point.

[0040] The present invention also provides an armored conductive component prepared by the above preparation method. Compared with the prior art where the core material and armor layer are manufactured separately and then completely cold-drawn to reduce the diameter, the armor layer prepared by the present invention has a smooth surface, less damage to the insulation layer, and a high yield.

[0041] refer to Figure 2 and Figure 3 In one specific embodiment, the apparatus for preparing the armored conductive component includes a continuous extrusion coating mechanism 1, an online cooling unit 2, an online diameter reduction unit 3, and a traction mechanism 4 arranged sequentially. The core material and the armor material are conveyed to the continuous extrusion coating mechanism 1, which is used to continuously extrude the armor blank to obtain an armor layer and coat it on the core material to obtain the precursor of the armored conductive component. The online cooling unit 2 is used to cool the precursor of the armored conductive component. The online diameter reduction unit 3 is used to reduce the diameter of the armor layer and attach the armor layer to the core material. The traction mechanism 4 is used to provide tension.

[0042] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A method for preparing an armored conductive component, characterized in that, Includes the following processes: Provide the core material to enable its forward transport; The armor material is continuously extruded to obtain an annular armor layer extrusion, which is formed outside the core material to obtain an armor conductive component precursor. In the armor conductive component precursor, the core material is suspended in the armor layer extrusion, and a first gap is provided between the core material and the armor layer extrusion. The armored conductive component precursor is cooled to reduce the temperature of the extruded armor layer to 0°C~30°C to obtain a solid armored conductive component precursor. A drawing die is provided, and a tensile force is applied to the solid armored conductive component precursor at the exit end of the drawing die, so that the solid armored conductive component precursor is cold drawn through the drawing die. During the cold drawing process, the volume mass conservation and non-section mass conservation are observed. The outer contour dimension of the armor layer extrusion material becomes smaller, the length of the armor layer extrusion material becomes longer, the thickness of the armor layer extrusion material remains basically unchanged, and the first gap is reduced to a second gap, thereby obtaining the armored conductive component.

2. The method for preparing the armored conductive component according to claim 1, characterized in that, The transmission speed of the core material The extrusion speed of the extruded material of the armor layer The following relationship exists: In the above formula, The thickness of the armor layer, The inner diameter of the armor layer before drawing is given. The inner diameter of the armor layer after drawing. The outer diameter of the armor layer before drawing is given. The outer diameter of the armor layer after it has been drawn.

3. The method for preparing the armored conductive component according to claim 1 or 2, characterized in that, The cold drawing process involves multiple drawing passes through two or more drawing dies.

4. The method for preparing the armored conductive component according to claim 3, characterized in that, The drawing die is provided with a drawing cavity, which includes a variable diameter section and a fixed diameter section connected in sequence. The inner diameter of the variable diameter section gradually decreases along the drawing direction, while the inner diameter of the fixed diameter section remains unchanged along the drawing direction.

5. The method for preparing the armored conductive component according to claim 4, characterized in that, The formula for calculating the tensile force is as follows: In the above formula, For tension, For the deformation resistance of the armor layer, For the armor layer in the first Friction in a drawing die For the number of drawing dies, The extrusion force of the armor layer extruded material. For the flow stress of the armor layer, This refers to the cross-sectional area of ​​the armor layer after drawing and reducing its diameter. This refers to the cross-sectional area of ​​the armor layer before diameter reduction. The coefficient of friction, For the first The die angle of the variable diameter section of a drawing die. For the first The length of the sizing section of a drawing die. For the first The inner diameter of the outlet of a drawing die. For the first The average inner diameter of each drawing die.

6. The method for preparing the armored conductive component according to claim 4 or 5, characterized in that, The elongation coefficient of each pass in the multi-pass drawing is less than 1.3; The die angle of each drawing die in the multi-pass drawing process is 5°~15°.

7. The method for preparing the armored conductive component according to claim 6, characterized in that, The die angle of each drawing die gradually decreases along the drawing direction.

8. The method for preparing the armored conductive component according to claim 7, characterized in that, The length of the sizing section of each drawing die gradually decreases along the drawing direction. The length of the sizing section of the first drawing die is 3mm to 16mm, and the length of the sizing section of the last drawing die is 1mm to 8mm.

9. The method for preparing the armored conductive component according to claim 1, characterized in that, The size of the second gap is less than 1 mm; The size of the first gap is 0.5mm to 10mm.

10. An armored conductive component, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 9.

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