CN219163742U - Electric transmission structure - Google Patents

Abstract

The utility model provides an electric transmission structure which comprises a copper terminal and an aluminum conductor which are connected through friction stir welding, wherein the aluminum conductor is provided with a first welding section suitable for friction stir welding, one end of the copper terminal is a plug-in end, the other end of the copper terminal is a second welding section matched with the first welding section in shape, and the first welding section is connected with the second welding section through a copper-aluminum transition layer. The utility model adopts friction stir welding to connect the copper terminal and the aluminum conductor, the microstructure change of a welding joint heat affected zone is small, the residual stress is lower, a welding workpiece is not easy to deform, the welding with longer welding lines, large cross sections and different positions can be completed at one time, the joint is high, the operation process is convenient to realize mechanization and automation, the equipment is simple, the energy consumption is low, the efficacy is high, the requirement on the operation environment is low, welding wires are not needed, an oxidation film is not needed before welding when the aluminum alloy is welded, shielding gas is not needed, the cost is low, and materials sensitive to thermal cracks can be welded, thereby being suitable for welding dissimilar materials.

Description

Electric transmission structure

Technical Field

The utility model belongs to the technical field of electric energy transmission, and particularly relates to an electric transmission structure.

Background

Copper or copper alloy has excellent electrical conductivity, thermal conductivity and plasticity, and is widely used in the field of electrical connection. However, copper resources are in shortage, the copper content in the crust is only about 0.01%, and the copper cost increases year by year with the increase of service life. For this reason, alternatives to metallic copper have been sought to reduce costs. For copper, aluminum has slightly poorer hardness, plasticity and corrosion resistance, but has lighter weight, conductivity is inferior to copper, and aluminum can partially replace copper in the field of electric connection. However, since the electrode potential difference between copper and aluminum is large, electrochemical corrosion occurs between copper and aluminum after direct connection, aluminum is easily corroded to increase the resistance of a connection region, and serious consequences such as functional failure, fire and the like are easily caused in electrical connection. The prior copper-aluminum connection modes are generally melt welding, cold pressure welding, electron beam welding, explosion welding and the like, the joint welded by the welding modes has high brittleness, air holes and cracks are easy to generate in the welding seam, particularly the welding seam under high-temperature treatment, the crystal grains become coarse, the mechanical property and the electrical property of the joint surface of the welding base material are seriously affected, and the requirements of the field of automobile electrical connection cannot be met. In order to increase the stability of the copper-aluminum contact surface of the copper-aluminum composite transmission system, the prior art increases the area of the copper-aluminum initial contact surface to obtain a more stable system. To ensure that the welding contact area absorbs sufficient energy, the output of welding energy is increased, resulting in a lot of cost waste.

Friction stir welding utilizes the heat generated by friction between a high-speed rotating welding tool and a workpiece to locally melt the welded material, when the welding tool moves forwards along a welding interface, the plasticized material flows from the front part to the rear part of the welding tool under the action of the rotating friction force of the welding tool, and a compact solid-phase welding seam is formed under the extrusion of the welding tool. Friction stir welding has many advantages: the microstructure of the heat affected zone of the welded joint has little change. Residual stress is low, and a welded workpiece is not easy to deform; the welding of longer welding seam, large cross section and different positions can be completed once: the operation process is convenient to realize mechanization and automation, the equipment is simple, the energy consumption is low, the efficacy is high, and the requirement on the operation environment is low; welding wires are not needed, an oxidation film is not needed before welding when aluminum alloy is welded, protective gas is not needed, and the cost is low; the weldable thermal crack sensitive material is suitable for dissimilar material welding: the welding process is safe, pollution-free, smoke-free, radiation-free and the like.

These advantages of friction stir welding are well suited for use in connection between copper terminals and aluminum conductors, but friction stir welding requires a high profile at the ends to be welded and requires similar connection of the two ends to be welded by friction stir welding. In practical use, the wire harness and the terminals are various, and it is difficult to directly select the raw materials suitable for directly performing friction stir welding connection between the copper terminals and the aluminum conductors, so a new solution is needed in the prior art to solve the above-mentioned problems.

Disclosure of Invention

The utility model aims to provide an electric transmission structure which solves the problems that a joint welded by a traditional welding mode between a copper terminal and an aluminum conductor is large in brittleness, air holes and cracks are easy to generate in a welding line, particularly the welding line under high-temperature treatment, grains become coarse, the mechanical performance and the electric performance of a welding substrate joint surface are seriously affected, and the requirements of the field of automobile electric connection cannot be met.

The utility model provides an electric transmission structure, which comprises a copper terminal and an aluminum conductor which are connected through friction stir welding; the aluminum conductor has a first weld segment adapted for friction stir welding; one end of the copper terminal is a plug-in end, the other end of the copper terminal is a second welding section matched with the first welding section in shape, and the first welding section is connected with the second welding section through a copper-aluminum transition layer.

Preferably, the aluminum conductor comprises a first conductor and a second conductor which are connected in a welded mode, the first welding section is arranged on the first conductor, a plating layer is arranged on at least part of the first conductor and the second conductor, and the plating layers of plating materials on the first conductor and the second conductor are different.

Preferably, the connection part of the first welding section and the second welding section is provided with the copper-aluminum transition layer formed by friction stir welding, and at least the surface of the copper-aluminum transition layer is provided with a first plating layer.

Preferably, at least part of the surface of the copper terminal is provided with a second plating layer, and the first plating layer and the second plating layer are made of different materials.

Preferably, at least the copper-aluminum transition layer is wrapped with an insulator, and the inner wall of the insulator is provided with a wear-resistant coating.

Preferably, the copper-aluminum transition layer contains copper-aluminum solid solution therein, wherein the copper-aluminum solid solution accounts for at least 45.6% of the total mass of the copper-aluminum transition layer.

Preferably, the second welding section has a through slot, the first welding section is at least partially disposed in the slot, the first welding section and the second welding section have radial coaxial through holes or threaded holes, and the first welding section and the second welding section are connected by a stud.

Preferably, the included angle between the copper terminal and the extending direction of the aluminum conductor is 90 degrees to 180 degrees.

Preferably, the aluminum conductor is an aluminum flat belt, and the second welding section is flat.

Preferably, the thickness of the first welded section is the same as the thickness of the second welded section.

Preferably, the aluminum conductor is an aluminum rod, and the second welding section is a cylinder.

Preferably, the ratio of the diameter of the cross section of the aluminum bar to the diameter of the cross section of the cylinder is 94-108%.

Preferably, the first welding section and the second welding section have intermeshing teeth.

Preferably, the aluminum conductors are a plurality of aluminum wires, and one ends of the aluminum wires are converged into the rigid first welding section.

Preferably, the length of the first welding section is not less than 3cm.

The beneficial effects of the utility model are as follows: the copper terminal and the aluminum conductor are connected in a friction stir welding mode, so that the mechanical property and the electrical property of a base material joint surface are improved, the requirements of the field of automobile electrical connection are met, the microstructure change of a heat affected zone of a friction stir welding joint is small, the residual stress is low, and a welding workpiece is not easy to deform; the welding device has the advantages that the welding device can finish welding of longer welding lines, large sections and different positions at one time, the joint is high, the operation process is convenient to realize mechanization and automation, the device is simple, the energy consumption is low, the efficacy is high, and the requirement on the operation environment is low; welding wires are not needed, an oxidation film is not needed before welding when aluminum alloy is welded, protective gas is not needed, and the cost is low; the weldable thermal crack sensitive material is suitable for dissimilar material welding: the welding process is safe, pollution-free, smoke-free, radiation-free and the like.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the utility model and together with the description, serve to explain the principles of the utility model.

FIG. 1 is a schematic view of an electrical transmission structure according to the present utility model;

FIG. 2 is a schematic view of another electrical transmission structure according to the present utility model;

FIG. 3 is a schematic view of another electrical transmission structure according to the present utility model;

FIG. 4 is a schematic view of another electrical transmission structure according to the present utility model;

FIG. 5 is a schematic view of another electrical transmission structure according to the present utility model;

FIG. 6 is a schematic view of another electrical transmission structure according to the present utility model;

fig. 7 is a schematic structural view of another electric transmission structure according to the present utility model.

The figures are marked as follows:

1-copper terminal, 11-plug-in end, 12-second welding section, 2-aluminum conductor, 21-first welding section, 3-insulator, 4-copper-aluminum transition layer.

Detailed Description

Various exemplary embodiments of the present utility model will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present utility model unless it is specifically stated otherwise.

The following description of at least one exemplary embodiment is merely exemplary in nature and is in no way intended to limit the utility model, its application, or uses.

Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of exemplary embodiments may have different values.

According to the present utility model, there is provided an electrical transmission structure, as shown in fig. 1 to 6, comprising a copper terminal 1 and an aluminum conductor 2 connected by friction stir welding; the aluminum conductor 2 has a first welding section 21 adapted for friction stir welding; one end of the copper terminal 1 is a plug-in end 11, the other end is a second welding section 12 matched with the first welding section 21 in shape, and the first welding section 21 is connected with the second welding section 12 through a copper-aluminum transition layer 4.

Copper or copper alloy has excellent electrical conductivity, thermal conductivity and plasticity, and is widely used in the field of electrical connection. However, copper resources are in shortage and copper costs increase year by year. For copper, aluminum has slightly poorer hardness, plasticity and corrosion resistance, but has lighter weight, conductivity is inferior to copper, and aluminum can partially replace copper in the field of electric connection. However, since the electrode potential difference between copper and aluminum is large, electrochemical corrosion occurs between copper and aluminum after direct connection, aluminum is easily corroded to increase the resistance of a connection region, and serious consequences such as functional failure, fire and the like are easily caused in electrical connection. The prior copper-aluminum connection modes are generally melt welding, cold pressure welding, electron beam welding, explosion welding and the like, the joint welded by the welding modes has high brittleness, air holes and cracks are easy to generate in the welding seam, particularly the welding seam under high-temperature treatment, the crystal grains become coarse, the mechanical property and the electrical property of the joint surface of the welding base material are seriously affected, and the requirements of the field of automobile electrical connection cannot be met. The first welding section 21 and the second welding section 12 are mutually penetrated or combined by copper and aluminum atoms to form the copper-aluminum transition layer 4, so that air and water do not exist between the first welding section 21 and the second welding section 12, electrochemical corrosion between copper and aluminum is slowed down, and the service life of the copper-aluminum wiring terminal is prolonged. The copper-aluminum transition layer 4 formed by the mutual penetration or combination of copper and aluminum atoms between the first welding section 21 and the second welding section 12 contains at least one of a copper simple substance, an aluminum simple substance, a copper-aluminum solid solution and a copper-aluminum compound. The copper aluminum compound contains a compound of copper element and aluminum element, and specific copper aluminum compounds include, but are not limited to, cu2Al, cu3Al2, cuAl2, and the like.

The design adopts friction stir welding to weld the first welding section 21 of the aluminum conductor 2 and the second welding section 12 of the copper terminal 1, the friction stir welding utilizes the heat generated by friction between a welding tool rotating at a high speed and a workpiece to locally melt the welded material, when the welding tool moves forwards along a welding interface, the plasticized material flows from the front part to the rear part of the welding tool under the action of the rotating friction force of the welding tool, and a compact solid-phase welding seam is formed under the extrusion of the welding tool. Friction stir welding has many advantages: the microstructure of the heat affected zone of the welded joint has little change. Residual stress is low, and a welded workpiece is not easy to deform; can once accomplish longer welding seam, big cross-section, the welding of different positions, joint height: the operation process is convenient to realize mechanization and automation, the equipment is simple, the energy consumption is low, the efficacy is high, and the requirement on the operation environment is low; welding wires are not needed, an oxidation film is not needed before welding when aluminum alloy is welded, protective gas is not needed, and the cost is low; the weldable thermal crack sensitive material is suitable for dissimilar material welding: the welding process is safe, pollution-free, smoke-free, radiation-free and the like.

In some embodiments, the aluminum conductor 2 includes a first conductor and a second conductor that are welded together, the first welding section is disposed on the first conductor, at least a part of the first conductor and the second conductor are disposed with a plating layer, and the plating layers of the plating materials on the first conductor and the second conductor are different.

It is often necessary to coat the aluminum conductors, and the aluminum conductors of the connection portions are often different from the aluminum conductors of the transmission portions, which requires a partial masking process. After the aluminum conductor is divided into a first aluminum conductor and a second aluminum conductor, plating layers are respectively carried out and then welded together.

The plating material contains one or more of gold, silver, nickel, tin, zinc, tin-lead alloy, silver-antimony alloy, palladium-nickel alloy, graphite silver, graphene silver and silver-gold-zirconium alloy. In order to demonstrate the influence of different plating materials on the overall performance of the conductor, the inventor uses the same specification and materials, adopts the first conductor and the second conductor sample of different plating materials, is favorable for a series of plugging times and corrosion resistance time tests, and in order to prove the advantages and disadvantages of the selected materials and other common electroplating materials, the inventor also selects tin, nickel and zinc as the plating materials for the experiment.

In some embodiments, the connection between the first welding section 21 and the second welding section 12 is provided with the copper-aluminum transition layer 4 formed by friction stir welding, and at least the surface of the copper-aluminum transition layer 4 is provided with a first plating layer.

The first plating layer is arranged on the copper-aluminum transition layer 4, and the plating layer is made of metal, so that the copper-aluminum transition layer 4 can be protected, and the conductive effect and the corrosion resistance can be achieved. The plating material contains one or more of gold, silver, nickel, tin, zinc, tin-lead alloy, silver-antimony alloy, palladium-nickel alloy, graphite silver, graphene silver and silver-gold-zirconium alloy. In order to demonstrate the influence of different plating materials on the overall performance of the conductor, the inventor uses the same specification and materials, adopts samples of different plating materials, is favorable for a series of test of the number of plugging times and corrosion resistance time, and in order to prove the advantages and disadvantages of materials and other common electroplating materials, the inventor also selects tin, nickel and zinc as the plating materials of the experiment.

The number of plugging times in table 1 is to fix the conductors on the experiment table respectively, simulate plugging by using a mechanical device, stop to observe the scratch of the surface coating of the copper-aluminum transition layer 4 under the condition that the surface coating is damaged and expose the material of the terminal after 100 times of plugging, stop the experiment and record the number of plugging times at that time. In this embodiment, the number of plugging times is less than 8000 and is not qualified.

The corrosion resistance time test in table 1 is to put the conductor into a salt spray test box, spray salt spray on each position of the conductor, take out the conductor every 20 hours to clean and observe the corrosion condition of the surface, namely, a period, stop the test until the corrosion area of the surface of the conductor is more than 10% of the total area, and record the period number at that time. In this embodiment, the number of cycles is less than 80 and is considered unacceptable.

Table 1, influence of different plating materials on the number of plugging times and corrosion resistance of copper-aluminum transition layer:

as can be seen from Table 1, when the plating material contains common metals of tin, nickel and zinc, the experimental results are far inferior to other selected metals, and although the plating nickel is qualified in the number of plugging times, the plating nickel is not more than the plating nickel, and the plating nickel is not qualified in the salt spray experiment. And the experimental results of other metals are selected, so that the experimental results exceed the standard value, and the performance is stable. Therefore, the inventors select the plating material of the copper-aluminum transition layer 4 to contain one or more of gold, silver-antimony alloy, graphite silver, graphene silver, palladium-nickel alloy, tin-lead alloy, or silver-gold-zirconium alloy.

In some embodiments, at least part of the surface of the copper terminal 1 is provided with a second plating layer, and the first plating layer and the second plating layer are made of different materials.

In some preferred embodiments, the first coating is a different material than the second coating. From the above description, it is known that the metal plating layers of different metal materials have different conductive effects and corrosion resistance, and the metal plating layers of higher price have better conductive effects and corrosion resistance, and can be inserted and pulled more, and use more complicated use environments, and longer service lives are obtained, but the use of these metal plating layers is limited due to higher price. Therefore, the inventors use gold, silver-antimony alloy, graphite silver, graphene silver, palladium-nickel alloy, tin-lead alloy or silver-gold-zirconium alloy as the second plating layer at the position of the copper terminal 1, which is exposed to the use environment, which is a metal material with excellent performance but high price, while the first plating layer is a position of the connection conductor, which is basically not relatively displaced after connection with the conductor, and is not exposed to the use environment under the protection of an insulator, so that the inventors use common metal tin, nickel and zinc as the plating material of the first plating layer to reduce the cost of the connection structure.

In some embodiments, an insulator 3 is wrapped at least at the copper-aluminum transition layer 4, and an inner wall of the insulator 3 is provided with a wear-resistant coating.

At least, the copper-aluminum transition layer 4 is wrapped with the insulator 3, and the wear-resistant coating is arranged on the inner wall of the insulator, so that the wear resistance is improved, at least the copper-aluminum transition layer 4 is protected, and the service life of the electric transmission structure is prolonged. The surface of the copper-aluminum transition layer 4 formed by friction stir welding is rough and is easy to damage the insulator 3, so that a wear-resistant coating is arranged at the position of the inner wall of the insulator 3 opposite to the welding line, and the insulator 3 is prevented from being damaged.

In some embodiments, the copper-aluminum transition layer 4 contains a copper-aluminum solid solution therein, the copper-aluminum solid solution accounting for at least 45.6% of the total mass of the copper-aluminum transition layer 4.

Friction stir welding utilizes the heat generated by friction between a high-speed rotating welding tool and a workpiece to locally melt a welded first welding section 21 and a welded second welding section 12, when the welding tool moves forwards along a welding interface, plastic material flows from the front part to the rear part of the welding tool under the action of the rotating friction force of the welding tool, and a compact copper-aluminum solid solution is formed in a copper-aluminum transition layer 4 under the extrusion of the welding tool. The microstructure of the heat affected zone of the welded joint after friction stir welding has small change, the residual stress is lower, and the welded workpiece is not easy to deform.

The copper-aluminum solid solution accounts for at least 45.6% of the total mass of the copper-aluminum transition layer 4, because the total weight of the copper-aluminum solid solution accounts for an important factor affecting the connectivity and conductivity of the copper matrix and the aluminum layer. In a number of tests it was found that the larger the total weight ratio of the copper-aluminium solid solution in the copper-aluminium transition layer 4, the more stable the connection, when the total weight ratio of the copper-aluminium solid solution in the copper-aluminium transition layer 4 is below a critical value, the mechanical strength and the electrical properties of the copper-aluminium transition layer 4 do not meet the performance requirements, but when the total weight ratio of the copper-aluminium solid solution in the copper-aluminium transition layer 4 is above this critical value, the performance rises sharply, and the mechanical strength and the electrical properties of the copper-aluminium transition layer are already satisfactory. In the present utility model, the copper-aluminum solid solution accounts for at least 45.6% of the total mass of the copper-aluminum transition layer 4.

Table 2: influence of total weight ratio of copper-aluminum solid solution in copper-aluminum transition layer on drawing force and voltage drop of copper-aluminum composite terminal

In this embodiment, the mechanical properties and electrical properties of the electrical connector are determined by: the drawing force is more than 200N, and the voltage drop is less than or equal to 0.5mV, so that the drawing force can be seen: when the total weight of the copper-aluminum solid solution is smaller than 45.6, the drawing force is obviously reduced, the voltage drop is obviously increased, and the mechanical property and the electrical property requirements of the electrical connector cannot be met, as can be seen from the table 2 above, when the total weight of the copper-aluminum solid solution in the copper-aluminum transition layer 4 is larger than 45.6%, the initial mechanical property and the electrical property of the copper-aluminum composite terminal can meet the requirements, and when the total weight of the copper-aluminum solid solution in the copper-aluminum transition layer 4 is increased, the mechanical property and the electrical property of the copper-aluminum composite terminal reach the standard requirement values, and the performance can be higher and higher, so the inventor sets that the copper-aluminum solid solution at least accounts for 45.6% of the total mass of the copper-aluminum transition layer 4.

In some embodiments, the second welding segment 12 has a slot therethrough, the first welding segment 21 is at least partially disposed within the slot, the first welding segment 21 and the second welding segment 12 have radially coaxial through holes or threaded holes, and the first welding segment 21 and the second welding segment 12 are connected by studs.

The first welding section 21 is clamped at two sides of the second welding section 12, then the first welding section is fixed by a stud, and finally the second welding section 12 is welded at the periphery by friction stir welding.

In some embodiments, the angle between the extension direction of the copper terminal 1 and the aluminum conductor 2 is 90 ° -180 °. That is, the plug copper terminal 1 and the aluminum conductor 2 can be designed into various angles according to the needs to meet the needs of different use environments.

In some embodiments, the aluminum conductor 2 is an aluminum ribbon and the second solder segment is flat. As shown in fig. 1 and 2, the requirements on the shapes of two ends to be welded by friction stir welding are high, the aluminum conductor is an aluminum flat belt, the second welding section is flat, the shapes of two connected ends are similar, the mechanical property and the electrical property of the bonding surface of the welding base material after friction stir welding are improved, and the requirements of the field of automobile electrical connection are met.

In some embodiments, the first weld segment is the same thickness as the second weld segment.

The friction stir welding is very suitable for being connected between the copper terminal and the aluminum conductor, the thickness of the first welding section of the aluminum conductor and the thickness of the second welding section of the copper terminal are the same, the condition that two similar connecting ends can be welded in a friction stir welding connection mode is met, and the two connecting ends are welded and are fully connected firmly.

In some embodiments, the aluminum conductor 2 is an aluminum rod and the second solder segment 12 is a cylinder. As shown in fig. 3 and 4, the requirements on the shapes of two ends to be welded by friction stir welding are high, the aluminum conductor is an aluminum rod, the second welding section is a cylinder, the shapes of the two connected ends are similar, the requirements of friction stir welding are met, the mechanical performance and the electrical performance of the joint surface of the welded base material after friction stir welding are improved, and the requirements of the field of automobile electrical connection are met.

The friction stir welding operation process is convenient to realize mechanization and automation, has simple equipment, low energy consumption, high efficiency and low requirement on the operation environment; the welding wire is not needed, the oxidation film is not needed before welding when the aluminum alloy is welded, the protective gas is not needed, and the cost is low.

In some embodiments, the ratio of the diameter of the aluminum bar cross section to the diameter of the cylinder cross section is 94% -108%.

In order to test the influence of the comparison on the conductivity, the inventor selects the aluminum bars and the columns with the diameters of the cross sections of the aluminum bars and the diameters of the cross sections of the columns being different, and tests the welded aluminum bars and columns. After conduction, the corresponding conductivity was measured and the test results are shown in table 3. In this embodiment, the conductivity is greater than 99.5% of ideal.

Table 3, effect of the ratio of the diameter of the aluminum bar cross section to the diameter of the cylinder cross section on the conductivity of the terminal:

as can be seen from table 3, when the ratio is less than 94%, the conductivity does not reach the ideal value range, and the conductivity is significantly reduced; when the ratio is more than 108%, the conductivity does not reach the ideal value range, so the inventor selects the most suitable ratio of the diameter of the cross section of the aluminum bar to the diameter of the cross section of the cylinder to be 94% -108%.

In some embodiments, the first weld segment and the second weld segment have intermeshing teeth. The tooth parts meshed with each other are more beneficial to welding of the first welding section and the second welding section through friction stir welding, and the whole structure is firmer after welding.

In some embodiments, the aluminum conductor 2 is a plurality of aluminum wires, and one ends of the plurality of aluminum wires are converged into the rigid first welding section 21. As shown in fig. 5 and 6, the plurality of aluminum wires may be melted and then friction stir welded with the second welding segment 12 to form a first welding segment 21.

In some embodiments, the length of the first welded segment is not less than 3cm.

Because friction stir welding utilizes the heat generated by friction between a welding tool rotating at a high speed and a workpiece to enable a welded material to be locally melted, when the welding tool moves forwards along a welding interface, the plasticized material flows from the front part to the rear part of the welding tool under the action of the rotating friction force of the welding tool, and a compact solid-phase welding seam is formed under the extrusion of the welding tool, the inventor verifies whether the length of a first welding section meets the welding length or not, and performs a welding test by selecting the first welding sections with different lengths and the second welding sections with the same length, and the specific result is shown in Table 4.

Table 4, whether the length of the first welded segment satisfies the welding length:

/>

according to the results shown in Table 4, when the length of the first welding section is less than 3cm, the friction stir welding utilizes the heat generated by friction between the welding tool rotating at a high speed and the workpiece to locally melt the welded material, so that the local melting of the welded material is insufficient, the first welding section and the second welding section cannot generate eutectic, and the first welding section and the second welding section cannot be connected after welding.

While certain specific embodiments of the utility model have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the utility model. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the utility model. The scope of the utility model is defined by the appended claims.

Claims (15)

1. An electrical transmission structure, characterized by: comprising a copper terminal and an aluminum conductor connected by friction stir welding;

the aluminum conductor has a first weld segment adapted for friction stir welding;

one end of the copper terminal is a plug-in end, the other end of the copper terminal is a second welding section matched with the first welding section in shape, and the first welding section is connected with the second welding section through a copper-aluminum transition layer.

2. An electrical transmission structure according to claim 1, wherein: the aluminum conductor comprises a first conductor and a second conductor which are connected in a welded mode, the first welding section is arranged on the first conductor, a plating layer is arranged on at least part of the area of the first conductor and the area of the second conductor, and the plating layers of the plating materials on the first conductor and the second conductor are different.

3. An electrical transmission structure according to claim 1, wherein: the joint of the first welding section and the second welding section is provided with the copper-aluminum transition layer formed by friction stir welding, and at least the surface of the copper-aluminum transition layer is provided with a first plating layer.

4. An electrical transmission structure according to claim 3, wherein: and at least part of the surface of the copper terminal is provided with a second plating layer, and the first plating layer and the second plating layer are different in material.

5. An electrical transmission structure according to claim 3, wherein: at least the copper-aluminum transition layer is wrapped with an insulator, and the inner wall of the insulator is provided with a wear-resistant coating.

6. An electrical transmission structure according to claim 1, wherein: the copper-aluminum transition layer contains copper-aluminum solid solution, and the copper-aluminum solid solution accounts for at least 45.6% of the total mass of the copper-aluminum transition layer.

7. An electrical transmission structure according to claim 1, wherein: the second welding section is provided with a through slot, the first welding section is at least partially arranged in the slot, the first welding section and the second welding section are provided with radial coaxial through holes or threaded holes, and the first welding section and the second welding section are connected through studs.

8. An electrical transmission structure according to claim 1, wherein: the included angle between the copper terminal and the extending direction of the aluminum conductor is 90-180 degrees.

9. An electrical transmission structure according to claim 1, wherein: the aluminum conductor is an aluminum flat belt, and the second welding section is flat.

10. An electrical transmission structure according to claim 9, wherein: the thickness of the first welding section is the same as that of the second welding section.

11. An electrical transmission structure according to claim 1, wherein: the aluminum conductor is an aluminum bar, and the second welding section is a cylinder.

12. An electrical transmission structure according to claim 11, wherein: the ratio of the diameter of the cross section of the aluminum bar to the diameter of the cross section of the cylinder is 94-108%.

13. An electrical transmission structure according to claim 12, wherein: the first weld segment and the second weld segment have intermeshing teeth.

14. An electrical transmission structure according to claim 1, wherein: the aluminum conductors are a plurality of aluminum wires, and one ends of the aluminum wires are converged into a rigid first welding section.

15. An electrical transmission structure according to claim 14, wherein: the length of the first welding section is not less than 3cm.

Images