CN211980234U

CN211980234U - Copper-aluminum composite electric energy transmission system

Info

Publication number: CN211980234U
Application number: CN202020456593.3U
Authority: CN
Inventors: 王超
Original assignee: Jilin Zhong Ying High Technology Co Ltd
Current assignee: Jilin Zhong Ying High Technology Co Ltd
Priority date: 2020-04-01
Filing date: 2020-04-01
Publication date: 2020-11-20
Anticipated expiration: 2030-04-01

Abstract

The utility model discloses a copper-aluminum composite electric energy transmission system, which comprises a copper terminal and an aluminum cable, wherein the aluminum cable comprises an aluminum conductor and an insulating layer arranged at the periphery of the aluminum conductor, and also comprises an electric energy transmission aluminum piece, and a section of aluminum conductor with the insulating layer stripped is compressed in the electric energy transmission aluminum piece to form a connecting piece; the electric energy transmission aluminum piece and the front end of the aluminum conductor form a melting layer, a welding platform is arranged at the end part of the copper terminal, which is used for being welded with the electric energy transmission aluminum piece, and the melting layer is coated on the welding platform to form a transition layer formed by mutually permeating metal atoms or mutually combining the metal atoms. The utility model improves the mechanical property of the copper-aluminum welding joint by reducing the internal stress between copper and aluminum; copper-aluminum compounds in the transition layer are reduced, and the electrical property of the copper-aluminum welding joint is improved; meanwhile, the path of the transition layer eroded by the external environment is increased, the problem of metal corrosion of the copper-aluminum welding joint is solved, and the service life of the copper-aluminum welding joint is prolonged.

Description

Copper-aluminum composite electric energy transmission system

Technical Field

The utility model relates to a conductive metal connecting piece technical field especially relates to a compound power transmission system of copper aluminium.

Background

Copper materials or copper alloy materials have good electrical conductivity, thermal conductivity and plasticity, and are widely used in the field of electrical connection. However, the copper resource is in short supply, the content of copper in the earth crust is only about 0.01%, and the cost of copper increases year by year with the increase of the service life. For this reason, alternatives to metallic copper are being sought to reduce costs.

The content of metal aluminum in the earth crust is about 7.73%, and after the refining technology is optimized, the price is relatively low, and the metal aluminum also has excellent electrical conductivity, thermal conductivity and plastic processability, so that the replacement of copper by aluminum is a main trend in the field of automobile electrical connection.

Aluminum has somewhat less hardness, plasticity, and corrosion resistance than copper, but is lighter in weight, has second only conductivity than copper, and can partially replace copper in the electrical connection field. However, because the electrode potential difference between the copper and the aluminum is large, electrochemical corrosion can be generated between the copper and the aluminum after direct connection, the aluminum is easy to corrode, so that the resistance of a connection area is increased, and serious consequences such as functional failure, fire and the like are easy to generate in electrical connection.

The prior copper-aluminum connection modes generally comprise fusion welding, cold welding, electron beam welding, explosion welding and the like, joints welded by the welding modes are high in brittleness, air holes and cracks are easy to generate in welding seams, particularly, crystal grains become large in the welding seams under high-temperature treatment, the mechanical property and the electrical property of a welding base material joint surface are seriously influenced, and the requirements in the field of automobile electrical connection cannot be met.

The existing copper-aluminum connection modes are generally friction welding, ultrasonic welding, resistance welding and the like, and in order to increase the stability of the copper-aluminum contact surface of the copper-aluminum composite transmission system, the area of the copper-aluminum initial contact surface is increased in the prior art so as to obtain a more stable system. The friction welding is to generate energy through the relative rotation friction of copper and aluminum welding pieces, the ultrasonic welding is to generate energy through the relative displacement friction of the copper and aluminum welding pieces, the resistance welding is to electrify the copper and aluminum welding pieces, generate energy through contact resistance, and then apply pressure to weld the copper and aluminum welding pieces together. Meanwhile, it should be noted that for friction welding and ultrasonic welding, the contact surface of the copper-aluminum weldment is relatively smooth and flat, so that the friction coefficient is reduced and the welding energy is reduced. For resistance welding, the flatter the weldment contact surface, the lower the contact resistance, and the lower the welding energy produced. The energy absorbed by welding is reduced, so that the welding quality between copper and aluminum is reduced, and batch accidents are easy to occur. To ensure that the weld contact area absorbs sufficient energy, the output of weld energy is increased, resulting in a significant cost waste.

In addition, friction welding's copper aluminium weldment relative rotation friction, in fact copper aluminium weldment's central point does not have relative linear velocity, be close to copper aluminium welded periphery more, copper aluminium weldment relative rotation's linear velocity is big more, consequently, the energy that copper aluminium weldment center and periphery friction produced is different, can lead to copper aluminium weldment center not welded yet, the periphery has excessively welded, the welding seam also can produce a large amount of internal stress simultaneously, the welded joint performance is qualified when welding the completion, after long-term the use, the brittle failure's of splice condition can appear, can lead to major accident when serious.

Therefore, in the technical field of conductive metal connecting pieces, a copper-aluminum composite electric energy transmission system which is simple in structure, more stable in welding process, better in mechanical property and electrical property and longer in service life is urgently needed.

SUMMERY OF THE UTILITY MODEL

In order to overcome the not enough of prior art, the utility model discloses a utility model aims to provide a compound power transmission system of copper aluminium, through reducing initial copper aluminium contact surface area, increase the initial coefficient of friction of copper aluminium contact surface, reduce the required energy of the compound power transmission system of preparation copper aluminium, improve the mechanical properties and the electrical property of the compound power transmission system of copper aluminium and reduce the use cost of the compound power transmission system of copper aluminium. Meanwhile, the transition layer is added to resist the external environment to corrode the path of the copper-aluminum composite electric energy transmission system, so that the corrosion problem of the copper-aluminum composite electric energy transmission system is solved, and the service life of the copper-aluminum composite electric energy transmission system is prolonged.

In order to achieve the above object, the present invention adopts the following technical solutions:

a copper-aluminum composite electric energy transmission system comprises a copper terminal and an aluminum cable, wherein the aluminum cable comprises an aluminum conductor and an insulating layer coated on the periphery of the aluminum conductor; the end part of the copper terminal, which is used for being welded with the connecting piece, is provided with a welding platform, and a transition layer which is formed by mutually permeating metal atoms or mutually combining the metal atoms is formed between the welding platform and the connecting piece.

As a further proposal, the front end of the connecting piece of the utility model is provided with a melting layer.

As a further scheme, the melting layer be in welding platform terminal surface forms the extension coating to copper terminal direction all around.

As a further aspect, the present invention provides the extension coating layer at least covering the end of the copper terminal.

As a further proposal, the thickness of the melting layer of the utility model is 0.01cm-15 cm.

As a further scheme, welded platform include with connecting piece welded terminal surface and with copper terminal end connection's root, the cross-sectional area of terminal surface is less than the cross-sectional area of root.

As a further aspect, the cross-sectional area of the end face of the welding platform of the present invention is at least 50% of the cross-sectional area of the root portion.

As a further proposal, the height of the welding platform is 0.01cm-15 cm.

As a further proposal, the transition layer of the utility model contains not less than 10 wt% of copper-aluminum solid solution.

As a further proposal, the thickness of the transition layer of the utility model is 0.01-6000 μm.

As a further proposal, the surface of the copper terminal is provided with a metal plating layer.

As a further proposal, the metal coating material of the present invention at least contains one of nickel, cadmium, zirconium, chromium, cobalt, manganese, aluminum, tin, titanium, zinc, copper, silver or gold.

As a further scheme, the aluminium cable still include the cladding be in the insulating layer periphery is used for shielding electromagnetic interference's shielding layer.

The utility model also discloses a processing method of copper aluminium composite electric energy transmission system, this processing method includes

Pre-assembling: sleeving the aluminum conductor with the insulating layer stripped into the electric energy transmission aluminum piece, and pressing the aluminum conductor into the electric energy transmission aluminum piece by using a pressing device to form a connecting piece wrapped by the electric energy transmission aluminum piece;

a welding step: and the copper terminal with the welding platform is welded with the connecting piece, and a transition layer formed by mutually permeating or combining metal atoms is formed between the welding platform and the connecting piece.

As a further aspect, the welding step of the present invention further comprises forming a melt layer at the front end of the connecting member.

As a further proposal, the processing method of the copper-aluminum composite electric energy transmission system of the utility model also comprises the manufacturing steps of the welding platform: and processing a welding platform on the end face of the copper terminal by using a mechanical processing device.

Compared with the prior art, the beneficial effects of the utility model reside in that:

1. copper aluminium composite electric energy transmission system different with current research result, prior art is the mechanical properties and the electrical properties that ensure copper aluminium composite electric energy transmission system through the copper aluminium initial contact area who increases among the copper aluminium composite electric energy transmission system to welding energy through increasing the compound electric energy transmission system of preparation copper aluminium ensures because of having increased the welding energy demand increase that initial contact area brought, thereby preparation copper aluminium composite electric energy transmission system's mode. The utility model discloses a reduce copper aluminium initial contact area, not only showing reduction the required energy of preparation copper aluminium composite power transmission system, still improved the mechanical properties and the electrical property of comparing prior art's copper aluminium composite power transmission system, showing the life who has prolonged copper aluminium composite power transmission system, reduced copper aluminium composite power transmission system's cost of manufacture. The utility model discloses an increase on the copper terminal be used for with the welded platform of connecting piece welded tip has reduced the initial area of contact of copper aluminium, increase the coefficient of friction of copper aluminium contact surface, it resists the route that external environment corrodes the compound power transmission system of copper aluminium to increase the transition layer, the mechanical properties and the electrical properties that have shown to increase the compound power transmission system of copper aluminium, the corrosion problems of copper aluminium has effectively been delayed, show the life who prolongs the compound power transmission system of copper aluminium, the energy demand of preparation compound power transmission system of copper aluminium has been reduced prominently, thereby make the cost of manufacture and the use cost of the compound power transmission system of copper aluminium definitely reduce.

2. Copper aluminium composite power transmission system, the front end of power transmission aluminium spare and aluminium conductor passes through welded platform and copper terminal welding, makes power transmission aluminium spare and aluminium conductor under the welded state, further fuses into the melting layer. The melting layer not only destroys compact oxide films on the surfaces of the electric energy transmission aluminum piece and the aluminum conductor, but also improves the mechanical property and the electrical property of the electric energy transmission aluminum piece and the aluminum conductor. Meanwhile, the Gibbs free energy of the melting layer is relatively low, and a transition layer mainly containing copper-aluminum solid solution can be formed with a welding platform more easily in the process of manufacturing the copper-aluminum composite electric energy transmission system, so that the weight ratio of brittle copper-aluminum compounds in the transition layer can be obviously reduced, and the mechanical and electrical properties of the copper-aluminum welding joint are obviously improved.

3. Copper aluminium composite electric energy transmission system copper terminal welding side set up welded platform, increased the final area of contact of copper terminal welding side and melting layer, the internal stress that produces when reducing copper aluminium welding, and then further strengthen the mechanical properties of copper aluminium face of weld.

4. When the welding mode is friction welding, the welding platform enables the central position of copper and aluminum welding to generate energy by friction firstly, then the root of the copper terminal generates energy by friction again, so that the energy generated during friction is more uniform, and the copper and aluminum compound with poorer electrical performance generated during welding is reduced, thereby improving the mechanical property and the electrical property of a welding surface, and reducing the cost for manufacturing the copper and aluminum composite electric energy transmission system.

5. When the welding mode is ultrasonic welding, under the same pressure, the mutual friction coefficient of the welding platform and the connecting piece is increased, so that the heat generated by friction is larger, the mechanical property and the electrical property of a welding surface are improved, and the cost for manufacturing the copper-aluminum composite electric energy transmission system is reduced.

6. When the welding mode is resistance welding, the contact resistance of the welding platform and the connecting piece is large, the generated energy is high, and the stability of the welding energy is ensured, so that the mechanical property and the electrical property of the welding surface are improved, and the cost for manufacturing the copper-aluminum composite electric energy transmission system is reduced.

7. Extend the coating cladding and be in the outside of transition layer can reduce external environment to the erosion of transition layer effectively. In addition, the outer side edge of the welding platform prolongs the erosion path of the transition layer by the external environment, increases the corrosion resistance of the copper-aluminum composite electric energy transmission system, and prolongs the service life of the copper-aluminum composite electric energy transmission system by about 20%.

8. Copper aluminium composite electric energy transmission system, can process out welded platform at copper terminal welding side by machining device before the welding, among the welding process, the melting layer with welded platform of copper terminal forms under the pressure effect with copper aluminium atom infiltration or the transition layer of inter combination, this transition layer can effectual reduction electrochemical corrosion between the copper aluminium, increases the weight percent of copper aluminium solid solution, reduces the production of fragile copper aluminium compound, increases copper aluminium composite electric energy transmission system life.

9. Copper aluminium composite power transmission system, can set up cladding material on the copper terminal, do not get rid of copper terminal cladding material before the welding, among the welding process, melting layer, copper terminal and cladding material metal form the atomic infiltration of copper, aluminium and cladding material metal or the transition layer of inter combination. The metal material of electric potential between copper aluminium or the extremely strong metal material of chemical stability can be selected for use to the cladding material metal, can slow down because the electrochemical corrosion that electric potential is big to arouse between the copper aluminium in the transition layer to the extension copper aluminium composite power transmission system's life.

10. Copper aluminium composite electric energy transmission system, can also contain the aluminium cable of taking the shielding layer, mainly use on the high-pressure pencil that the electric motor car used. The weight of the electric vehicle wire harness can be remarkably reduced, the energy consumption is reduced, and meanwhile, the cost of the high-voltage wire harness is reduced.

11. Processing method of copper aluminium composite electric energy transmission system, still include welded platform preparation step, use machining device welded platform is processed out on the terminal surface of copper terminal, can show the cost of manufacture that reduces copper aluminium composite electric energy transmission system. The method for manufacturing the welding platform on line can also obviously improve the qualified rate of the copper-aluminum composite electric energy transmission system, thereby further reducing the manufacturing loss cost.

Drawings

Fig. 1 is a schematic structural view of butt welding of the copper-aluminum composite electric energy transmission system of the present invention;

fig. 2 is a schematic structural view of butt welding of the copper-aluminum composite electric energy transmission system of the present invention;

fig. 3 is a schematic structural view of the overlap welding of the copper-aluminum composite electric energy transmission system of the present invention;

fig. 4 is a schematic structural diagram of a copper-aluminum composite power transmission system according to the present invention, which uses an aluminum cable with a shielding layer;

fig. 5 is a schematic structural diagram of an aluminum cable with a shielding layer and an outer insulating layer used for butt welding of the copper-aluminum composite power transmission system of the present invention;

fig. 6 is an electron mirror image of the transition layer according to the present invention;

fig. 7 is an electron image enlarged view and an X-ray energy spectrum of the test point 1 in fig. 5, wherein a is the electron image enlarged view, and b is the X-ray energy spectrum;

FIG. 8 is a drawing of a tension simulation experiment of a copper-aluminum composite power transmission system without a welding platform at the welding end of the copper terminal;

FIG. 9 is a drawing of a result of a tension simulation experiment for a copper-aluminum composite power transmission system without a welding platform at the welding end of the copper terminal;

FIG. 10 is a drawing of a tension simulation experiment of a copper-aluminum composite power transmission system with a welding platform at the welding end of a copper terminal;

FIG. 11 is a drawing of a tensile force simulation experiment result of a copper-aluminum composite power transmission system with a welding platform at a welding end of a copper terminal;

wherein the reference symbols are: 1. copper terminal, 11, welded platform, 12, transition layer, 2, aluminium conductor, 3, insulating layer, 31, outer insulating layer, 4, electric energy transmission aluminium part, 41, conductor crimping section, 42, transition section, 43, insulating layer crimping section, 5, melting layer, 6, aluminium cable, 7, extension cladding, 8, shielding layer.

Detailed Description

To further illustrate the technical means and effects of the present invention adopted to achieve the intended purpose of the present invention, the following detailed description is given to the embodiments, structures, features and effects according to the present invention with reference to the accompanying drawings and preferred embodiments as follows:

as shown in fig. 1, a copper-aluminum composite electric energy transmission system comprises a copper terminal 1 and an aluminum cable 6, wherein the aluminum cable 6 comprises an aluminum conductor 2, an insulating layer 3 coated on the periphery of the aluminum conductor 2, and an electric energy transmission aluminum piece 4, and a section of the aluminum conductor 2 with the insulating layer stripped is coated in the electric energy transmission aluminum piece 4 to form a connecting piece; the end part of the copper terminal 1, which is used for being welded with the connecting piece, is provided with a welding platform 11, and a transition layer 12 formed by metal atoms mutually permeating or combined with the metal atoms is formed between the welding platform 11 and the connecting piece.

As a further preferable scheme, the electric energy transmission aluminum piece can adopt, but is not limited to, an electric conduction aluminum piece of an aluminum tubular structure.

The transition layer of the mutual infiltration of the metal atoms or the mutual combination of the metal atoms in the utility model means that the connecting piece and the copper terminal generate energy through friction or current or electric arc, then mutual extrusion pressure is applied to the connecting piece and the copper terminal through welding equipment, and the mutual infiltration of the copper and aluminum atoms is dissolved into each other crystal lattices under the action of the energy of the copper and aluminum atoms at a welding interface to generate copper and aluminum solid solution; in addition, a small amount of copper atoms and aluminum atoms may be bonded by a metal bond to produce a copper aluminum compound.

Because of the large potential difference between copper and aluminum, the service life of the common copper and aluminum electrical connection is reduced due to electrochemical corrosion. The utility model discloses in, produce the metal atom and interpenetrate or the transition layer of metal atom inter combination between the copper aluminium, electrochemical corrosion between the copper aluminium that can effectual reduction prolongs copper aluminium composite power transmission system's life is about 20%, has also improved the electrical properties and the mechanical properties that copper aluminium is connected simultaneously.

As shown in fig. 5 and 6, the transition layer of the copper-aluminum welding interface can be seen for the electron mirror image of the transition layer. And an X-ray energy spectrum diagram is carried out on the transition layer, so that the approximate element distribution of the transition layer can be seen.

As a further proposal, the front end of the connecting piece of the utility model is provided with a melting layer 5. No gap exists between the melting layer and the electric energy transmission aluminum piece and between the melting layer and the aluminum conductor, seamless connection of the copper terminal and the joint between the electric energy transmission aluminum piece and the aluminum conductor is effectively guaranteed, and mechanical performance and electrical performance of the copper-aluminum composite electric energy transmission system can be further guaranteed.

Copper aluminium composite electric energy transmission system, the front end of electric energy transmission aluminium spare and aluminium conductor passes through welded platform and copper terminal welding, makes electric energy transmission aluminium spare and aluminium conductor under the welded state, further fuses into the melting layer, has destroyed the fine and close oxide film on electric energy transmission aluminium spare and aluminium conductor surface, both improved the mechanical properties and the electrical property of electric energy transmission aluminium spare and aluminium conductor, also can better formation transition layer in follow-up welding process.

In a preferred embodiment, the melting layer 5 of the present invention forms an extending coating layer around the end surface of the welding platform 11 toward the copper terminal.

Since the melting point of copper is 1083 c and the melting point of aluminum is 660 c, actually, the aluminum is heated to a molten state by heat generated after copper and aluminum are welded, and a molten layer is formed. The melting layer 5 forms an extension coating layer 7 around the end face of the welding platform 11 towards the direction of the copper terminal, so that the welding seam of the copper-aluminum welding surface can be protected, the copper-aluminum welding surface is prevented from directly contacting the external environment in use, the possibility of corrosion of the copper-aluminum welding surface is reduced, and the service life of the copper-aluminum composite electric energy transmission system is prolonged. In addition, in the conventional welding method, the molten layer is expanded to the periphery by pressure to generate burrs, and the burrs are cut off by an additional process in the subsequent use. The utility model discloses a melting layer directly forms in copper terminal direction and extends the coating under welding equipment's anchor clamps shaping groove effect, has saved the process that the overlap excision has also beautified copper aluminium composite power transmission system's outward appearance.

The utility model discloses in, through the research discovery, the thickness of melting layer 5 influences the joint strength between copper terminal 1 and aluminium conductor 2 and the power transmission aluminium part 4, and the concrete expression is: when the thickness of the melting layer 5 is too small, the reason is that the friction strength of copper and aluminum is insufficient or the welding heat generated by small current is insufficient to melt more electric energy transmission aluminum pieces 4 and aluminum conductors 2, so that the strength of the melting layer 5 and the transition layer 12 is insufficient, and the mechanical property of the copper and aluminum composite electric energy transmission system is reduced. In addition, the thickness of the melting layer 5 is too small, the thickness of the transition layer 12 is too small or the transition layer 12 is not formed, and the electrochemical corrosion degree between copper and aluminum is greatly increased, so that the electrical performance and the service life of the copper-aluminum composite electric energy transmission system are reduced. When the thickness of the melting layer 5 is too large, the welding heat is too high due to too large copper-aluminum friction strength or large current, more electric energy transmission aluminum pieces 4 and aluminum conductors 2 are melted and then cooled to form a metal structure with thick crystal lattices, more copper-aluminum compounds are mixed in, the mechanical strength of the melting layer 5 is not as good as that of base material materials of the electric energy transmission aluminum pieces and the aluminum conductors 2, and the mechanical property of the copper-aluminum composite electric energy transmission system is reduced. Meanwhile, the melting layer 5 and the transition layer 12 are mixed with more copper-aluminum compounds with poor conductivity, so that the electrical property of the copper-aluminum composite electric energy transmission system is also reduced. Therefore, in the present invention, it is further preferable that the thickness of the molten layer is 0.01cm to 15 cm.

As a further aspect of the present invention, the extension coating layer 7 at least covers the end of the copper terminal.

Extension coating cladding to copper terminal tip, can avoid external environment to the erosion of transition layer effectively. In addition, the outer side edge of the welding platform prolongs the erosion path of the transition layer by the external environment, increases the corrosion resistance of the copper-aluminum composite electric energy transmission system, and prolongs the service life of the copper-aluminum composite electric energy transmission system by about 20%.

As a further scheme, welded platform include with connecting piece welded terminal surface and with copper terminal end connection's root, the cross-sectional area of terminal surface is less than the cross-sectional area of root. In the welding process, the end face of the copper terminal which rubs with an electric energy transmission aluminum piece and an aluminum cable is mainly the end face of a welding platform, in order to meet the requirement of generating enough friction energy, the end face of the welding platform cannot be too small, and if the contact friction area of copper and aluminum is too small, the mechanical property and the electrical property of a welding joint can be influenced because the thickness of a transition layer is insufficient due to insufficient welding energy. Therefore, in order to obtain the welded joint with more excellent performance, it is preferable that the cross-sectional area of the welding platform end face is at least 50% of the cross-sectional area of the root portion.

The utility model discloses in, set up welded platform at copper terminal faying face, during copper aluminium welding, the welded platform that central point put on the one hand produces energy earlier, then the welded platform side, the welded platform bottom surface at last, the bigger region of linear velocity, weld time is shorter more, and the energy that produces when making the welding is more even, reduces the relatively poor copper aluminium compound of electrical property that produces when welding to the electrical property of faying face has been improved. In another aspect. The welding platform is arranged at the end part of the copper terminal, so that the contact area between the welding side of the copper terminal and the melting layer can be increased, the internal stress generated during copper-aluminum welding is reduced, and the mechanical property of a welding surface is enhanced. Furthermore, extension coating cladding be in the outside of transition layer can reduce external environment to the erosion of transition layer effectively. The outer side edge of the welding platform prolongs the erosion path of the transition layer by the external environment, increases the corrosion resistance of the copper-aluminum composite electric energy transmission system, and prolongs the service life of the copper-aluminum composite electric energy transmission system by about 20%. Preferably, the height of the welding platform is 0.01cm-15 cm.

It should be noted that the transition layer at least contains a simple substance of copper, a simple substance of aluminum, a copper-aluminum solid solution, and a copper-aluminum compound. The copper-aluminium compound is Cu₂Al，Cu₃Al₂，CuAl，CuAl₂One or more of (a). When the transition layer contains less than 10 wt% of solid solution of copper and aluminum, the other components in the transition layer are greater than 90 wt%. The transition layer has a large ratio of simple copper to simple aluminum, which means that the copper-aluminum welding is not sufficient, and the simple copper-aluminum is not fused into copper-aluminum solid solution. The transition layer is large in proportion of copper-aluminum compounds, the conductivity of the copper-aluminum compounds is very poor, the brittleness of the copper-aluminum compounds is high, and the mechanical property and the electrical property of the copper-aluminum composite base material can be reduced when the content of the copper-aluminum compounds is large. Therefore, the transition layer of the present invention at least contains 10 wt% of copper-aluminum solid solution.

The utility model discloses in, the 12 undersize of transition layer thickness, the electrochemical corrosion degree between the copper aluminium can greatly increase to reduce copper aluminium composite power transmission system's electrical property and life. The transition layer 12 has an excessively large thickness, and the electrical performance of the copper-aluminum composite power transmission system is also reduced due to the inclusion of more copper-aluminum compounds with poor electrical conductivity.

As a further proposal, the surface of the copper terminal is provided with a metal plating layer. Because the copper terminal needs to be connected with the power consumption device, consequently can expose in air and aquatic, still have the salinity in the air of some places even, the copper terminal can receive oxidation and salt fog corruption to reduce the life of terminal, the terminal can take place the short circuit when serious and lead to the burning accident, causes bigger loss. Therefore, the metal coating is arranged on the surface of the copper terminal, so that the corrosion of air, water and salt mist can be effectively prevented, the service life of the copper terminal and even the service life of the copper-aluminum connector are prolonged, and the occurrence of safety accidents is reduced. The plating metal can be made of a metal material with an electric potential between copper and aluminum, and can slow down electrochemical corrosion caused by a large electric potential between copper and aluminum in the transition layer, so that the service life of the copper-aluminum composite electric energy transmission system is prolonged. Therefore, it is preferable that the metal plating layer material of the present invention includes, but is not limited to, at least one of nickel, cadmium, zirconium, chromium, cobalt, manganese, aluminum, tin, titanium, zinc, copper, silver, or gold.

As a further scheme, aluminium cable still include the cladding be in the insulating layer periphery is used for shielding electromagnetic interference's shielding layer 8. Compound electric energy transmission system of copper aluminium weld the aluminium cable of taking the shielding layer, mainly use on the high-pressure pencil that the electric motor car used. The weight of the electric vehicle wire harness can be reduced, the energy consumption is reduced, and meanwhile, the cost of the high-voltage wire harness is reduced.

The following are specific embodiments of the present invention, and in the following embodiments, except for the limitation of the present invention, the adopted devices, apparatuses, test methods, etc. all belong to the prior art.

Example 1

The copper-aluminum composite electric energy transmission system comprises an aluminum conductor, an electric energy transmission aluminum piece, an aluminum conductor and a connecting piece, wherein the aluminum conductor is wrapped by the electric energy transmission aluminum piece.

The copper-aluminum composite electric energy transmission system is processed by the following process:

clamping: clamping a copper terminal with a welding platform in a rotary fixture of friction welding equipment, and installing the aluminum conductor and the electric energy transmission aluminum piece which are subjected to the pre-installation step in a movable fixture;

a welding step: copper terminal is rotatory under the drive of rotary fixture, and rotary fixture's rotational speed is 1000R Min, it drives to remove anchor clamps connecting piece horizontal migration extrudees to rotatory copper terminal, and the pressure that removes anchor clamps is 10000N, is in through the frictional heating connecting piece front end forms the melting layer, then makes under the pressure the melting layer cladding is in on the welded platform of copper terminal welding end to form with welded platform and use metal atom infiltration or the transition layer of inter combination mutually.

In this embodiment, the utility model detects the structure of the transition layer, and the detection result is shown in fig. 6 to 7.

Example 2

Further, in order to demonstrate that the welding end of the copper terminal is provided with a welding platform and is not provided with the influence of the welding platform on the mechanical property and the electrical property of the copper-aluminum composite electric energy transmission system, the utility model discloses the people has carried out a series of experiments on the mechanical property, the electrical property and the service life of the copper-aluminum composite electric energy transmission system of the two kinds of differences.

The specific experimental process is as follows: the practical use environment of the copper-aluminum composite electric energy transmission system is simulated, but the test condition is increased to a degree which is extremely severe to the common environment, and the test effect which can be achieved in a long time under the practical use environment can be obtained in a short time. The series of experiments included: 1) testing the initial drawing force and voltage drop to obtain the initial performance of the copper-aluminum composite electric energy transmission system; 2) the salt spray test is carried out for 1000 hours, and salt water is sprayed on a copper-aluminum composite electric energy transmission system by using a salt spray test box, so that the ten-year salt spray resistance test in the ordinary coastal environment can be replaced; 3) 200-hour high and low temperature experiments show that the copper-aluminum composite electric energy transmission system is respectively at the highest temperature and the lowest temperature of the use environment for one hour, the temperature switching time is less than 5 seconds, 100 cycles are carried out, and the high and low temperature resistance test for 10 years in the external cold and hot alternating environment can be replaced; 4) the vibration test is carried out for 120 hours, the copper-aluminum composite electric energy transmission system is fixed on a vibration test table, the vibration amplitude is selected according to the use environment, the vibration of the copper-aluminum composite electric energy transmission system is carried out in three directions, and the vibration test for 10 years in the common use vibration environment can be replaced; 5) 6000-hour aging experiment, the copper-aluminum composite electric energy transmission system is placed in an aging experiment box, the environment exceeding the rated use condition is simulated, and the aging test under the 20-year common use environment can be replaced. After each experiment, the voltage drop value and the drawing force value of the copper-aluminum composite electric energy transmission system are tested. The results of the experiments are shown in tables 1-1, tables 1-2 and tables 1-3.

Tables 1 to 1: influence of copper terminal welding platform on drawing force and voltage drop of copper-aluminum composite electric energy transmission system (before experiment and after 1000 hours salt spray experiment)

Tables 1 to 2: influence of copper terminal welding platform on drawing force and voltage drop of copper-aluminum composite electric energy transmission system (200 hours high and low temperature experiment and 120 hours vibration)

Tables 1 to 3: influence of copper terminal welding platform on drawing force and voltage drop of copper-aluminum composite electric energy transmission system (6000 hours aging experiment)

As can be seen from the results of the above tables 1-1, tables 1-2 and tables 1-3: the copper terminal welding end is provided with the copper-aluminum composite electric energy transmission system of the welding platform, the initial drawing force value is far higher than that of the copper-aluminum composite electric energy transmission system without the welding platform at the copper terminal welding end, and the voltage drop value is smaller. After respectively passing through a 1000-hour salt spray test, a 200-hour high and low temperature test, a 120-hour vibration test and a 6000-hour aging test, the copper terminal welding end is provided with the copper-aluminum composite electric energy transmission system of the welding platform, and the drawing force of the copper-aluminum composite electric energy transmission system after the tests is still higher than the initial drawing force of the copper-aluminum composite electric energy transmission system without the welding platform at the copper terminal welding end. And copper-aluminum composite electric energy transmission system that copper terminal welding end does not take welded platform, the drawing force after the experiment is obvious lower, and mechanical properties is unstable, probably causes copper-aluminum composite electric energy transmission system to break away from to lead to the cable short circuit, light then the function is invalid, heavy then leads to the burning accident. The copper terminal welding end is provided with a copper-aluminum composite electric energy transmission system of a welding platform, and the voltage drop after the experiment is basically the same as the initial voltage drop of the copper-aluminum composite electric energy transmission system without the welding platform at the copper terminal welding end. And copper terminal welding end does not take welding platform's copper aluminium composite power transmission system, and the voltage drop after the experiment also obviously reduces, and electrical properties is unstable, and copper aluminium composite power transmission system contact resistance risees, can cause the copper aluminium composite power transmission system to generate heat and redden during electrically conductive, can burn because of the high temperature when serious, causes serious accident.

Example 3

As shown in fig. 2 and 3, a copper-aluminum composite electric energy transmission system comprises a copper terminal 1 and an aluminum cable 6, wherein the aluminum cable 6 comprises an aluminum conductor 2 and an insulating layer 3 coated on the periphery of the aluminum conductor 2, and further comprises an electric energy transmission aluminum piece 4, and a section of the aluminum conductor 2 with the insulating layer stripped and at least part of the aluminum conductor with the insulating layer 3 are coated in the electric energy transmission aluminum piece 4 to form a connecting piece; the end part of the copper terminal 1, which is used for being welded with the connecting piece, is provided with a welding platform 11, and a transition layer 12 formed by metal atoms mutually permeating or combined with the metal atoms is formed between the welding platform 11 and the connecting piece.

As a further scheme, as shown in fig. 2 and fig. 3, the aluminum part for electric energy transmission according to the present invention includes a conductor crimping section 41, an insulating layer crimping section 43 and a transition section 42, wherein the inner diameter of the insulating layer crimping section 43 is greater than that of the conductor crimping section 41, and the conductor crimping section 41 and the insulating layer crimping section 43 are connected by the step-shaped transition section 42; the aluminum conductor 2 is sleeved in the conductor crimping section 41 in a matching mode, the insulating layer 3 is in interference fit with the insulating layer crimping section 43, and the front end of the insulating layer 3 does not enter the conductor crimping section 41. In this scheme, through the interference fit between insulating layer and the power transmission aluminium alloy, further avoid producing the space between power transmission aluminium alloy and the aluminium conductor, stopped air and moisture and got into the inside possibility of power transmission aluminium alloy, effectively prevented metal corrosion. The front end of the insulating layer is positioned in the transition section, the step-shaped transition section can accommodate the insulating layer which deforms and extends in the crimping process, so that the phenomenon that the resistance is increased due to the fact that the insulating layer is pressed into the conductor is prevented, and the copper-aluminum composite electric energy transmission system generates heat and even burns.

pre-assembling: sleeving the aluminum conductor with the stripped insulating layer into an electric energy transmission aluminum piece, and pressing the aluminum conductor with the stripped insulating layer and part of the aluminum conductor with the stripped insulating layer in the electric energy transmission aluminum piece by using a pressing device to form a connecting piece;

clamping: clamping a copper terminal with a welding platform in a rotary fixture of friction welding equipment, and installing the connecting piece subjected to the pre-installation step in a movable fixture;

In this embodiment, in order to examine the influence of the welding platform on the welding effect of the copper terminal and the performance of the welded joint, the utility model obtains the copper-aluminum composite power transmission system by the copper terminal with the welding platform and the copper terminal without the welding platform according to the above method, the copper terminal without the welding platform directly forms a transition layer with the front end of the connecting piece forming a melting layer, and the two copper-aluminum composite power transmission systems are subjected to a tensile force simulation experiment by simulation software Ansys, wherein the simulation experiment method is to introduce the copper terminal with the welding platform, the copper terminal without the welding platform and the digital model of the front end of the connecting piece forming the melting layer into simulation software, respectively apply tensile force at the two ends of the copper terminal and the connecting piece, the applied tensile force is 1700N, and then the software automatically simulates the internal stress of an interface, the internal stress is larger, the less stable the weld, the lower the pull force. The process and the results of the tensile force simulation experiment are shown in fig. 8 to 11.

The results of fig. 8 to 11 show that: the internal stress of the joint without the welding platform at the welding end of the copper terminal is 10.887Mpa, and the internal stress of the joint with the welding platform at the welding end of the copper terminal is 8.2405 Mpa. It can be seen through the internal stress at the weld that the internal stress of the joint with the weld land at the copper terminal weld end is reduced by 24.3% compared to the joint without the weld land at the copper terminal weld end. The smaller the internal stress is, the more difficult the copper-aluminum composite electric energy transmission system is to break during drawing, which shows that the welding performance of the copper-aluminum composite electric energy transmission system with the welding platform arranged at the welding end of the copper terminal is obviously better.

Example 4

As shown in fig. 3, a copper-aluminum composite electric energy transmission system comprises a copper terminal 1 and an aluminum cable 6, wherein the aluminum cable 6 comprises an aluminum conductor 2 and an insulating layer 3 coated on the periphery of the aluminum conductor 2, and further comprises an electric energy transmission aluminum piece 4, and a section of the aluminum conductor 2 with the insulating layer stripped and at least part of the aluminum conductor with the insulating layer 3 are coated in the electric energy transmission aluminum piece 4 to form a connecting piece; the end part of the copper terminal 1, which is used for being welded with the connecting piece, is provided with a welding platform 11, and a transition layer 12 formed by metal atoms mutually permeating or combined with the metal atoms is formed between the welding platform 11 and the connecting piece.

clamping: clamping a copper terminal with a welding platform in a fixing clamp of ultrasonic equipment, and installing the connecting piece subjected to the pre-installation step in a vibration clamp of the ultrasonic equipment;

a welding step: copper terminal immobility in mounting fixture, vibration anchor clamps drive connecting piece horizontal vibration extrudees to fixed copper terminal, and the frequency of vibration anchor clamps is 200KHz, and pressure is 10000N, is in through vibration friction themogenesis the connecting piece front end forms the melting layer, then makes under the pressure the melting layer cladding is in on the welded platform of copper terminal weld end to form with welded platform and use metal atom infiltration or the transition layer of inter combination mutually.

The purpose of this example is to demonstrate the influence of different molten layer thicknesses on the drawing force, voltage drop and welding strength of the copper-aluminum composite electric energy transmission system, examine the drawing force values, voltage drop values and welding strength of the copper-aluminum composite electric energy transmission system with different molten layer thicknesses, and see table 2 for the results.

Table 2: influence of different molten layer thicknesses on drawing force and voltage drop of copper-aluminum composite electric energy transmission system

From the above table, it can be seen that when the thickness of the melting layer is less than 0.01cm, the drawing force is significantly low, the voltage drop value is high, the performance of the obtained copper-aluminum composite electric energy transmission system is relatively poor, meanwhile, because the thickness of the melting layer is too small, the heat generated by the friction of copper and aluminum is small, the strength of the melting layer and the transition layer of the copper-aluminum composite electric energy transmission system is weak, and the mechanical property and the electrical property of the welded copper-aluminum composite electric energy transmission system are also relatively weak.

When the melting layer is larger than 15cm, the drawing force has a relatively obvious reduction trend, the voltage drop value is also obviously increased, the performance of the obtained copper-aluminum composite electric energy transmission system is relatively poor, the heat generated by the friction of copper and aluminum can be increased, more connecting pieces are melted at the front ends in the friction welding process and then cooled, a metal structure with thick crystal lattices is formed, and more copper-aluminum compounds with poor conductivity can be generated, so that the mechanical property and the electrical property of the copper-aluminum composite electric energy transmission system have a tendency of reduction.

Therefore, in the utility model discloses in, preferably, the thickness of melting layer is 0.01cm ~ 15cm, and the pulling power value, the voltage drop value and the welding strength of the compound electric energy transmission system of copper aluminium who obtains all have obvious advantage.

Example 5

clamping: clamping a copper terminal with a welding platform in a lower electrode of resistance welding equipment, and installing the connecting piece subjected to the pre-installation step in an upper electrode of the resistance welding equipment;

a welding step: copper terminal is immovable in the bottom electrode, go up the electrode drive the connecting piece downstream and to fixed copper terminal circular telegram and extrusion, the electric current that resistance welding equipment was applyed is 40KA, the pressure that goes up the electrode and applys is 10000N, through the conductive themogenesis of contact resistance the connecting piece front end forms the melting layer, then makes under the pressure the melting layer cladding is in on the welding bench of copper terminal welding end to form with welding bench and use metal atom interpenetration or the transition layer of intercombination.

In this embodiment, in order to demonstrate the influence of the height of the welding platform on the drawing force and the voltage drop of the copper-aluminum composite electric energy transmission system and the welding strength, the utility model discloses a drawing force value, the voltage drop value and the welding strength of the copper-aluminum composite electric energy transmission system with different heights of the welding platform are investigated, and the results are shown in table 3.

Table 3: influence of different welding platform heights on drawing force and voltage drop of copper-aluminum composite electric energy transmission system

The results in table 3 show that: when the height of the welding platform is lower than 0.01cm, the welding platform is very close to a flush welding end face, and the mechanical property and the electrical property of the copper-aluminum composite electric energy transmission system are at a lower level. When the height of the welding platform is higher than 15cm, in order to enable the fusion layer to be in full contact with the welding end face of the copper terminal and form a transition layer, higher friction heat and pressure are required to be provided by welding equipment, and the heat and pressure borne by the end face and the bottom face of the welding platform are inconsistent, so that the thickness of the fusion layer and the thickness of the transition layer are uneven, the contact resistance is increased, and the mechanical property and the electrical property of the copper-aluminum composite electric energy transmission system tend to be reduced.

Further, in this embodiment, in order to demonstrate the influence of the welding platform end surface area on the drawing force and voltage drop of the copper-aluminum composite electric energy transmission system and the welding strength, the utility model discloses the drawing force value, the voltage drop value and the welding strength of the copper-aluminum composite electric energy transmission system of different welding platform end surface areas have been investigated, and the results are referred to table 4.

Table 4: influence of the ratio of the cross-sectional areas of the end surfaces of different welding platforms to the cross-sectional area of the root of the end surfaces on the drawing force and voltage drop of the copper-aluminum composite electric energy transmission system

From the results in table 4, it can be seen that, in order to generate sufficient friction heat, the end surface of the welding platform cannot be too small, and when the contact friction area of copper and aluminum is greater than 50% in the welding process, a copper-aluminum joint with excellent electrical and mechanical properties can be obtained.

Example 6

As shown in fig. 4, a copper-aluminum composite electric energy transmission system comprises a copper terminal 1 and an aluminum cable 6, wherein the aluminum cable comprises an aluminum conductor, an insulating layer 3 coated on the periphery of the aluminum conductor, a shielding layer 8 coated on the periphery of the insulating layer 3 and used for shielding electromagnetic interference, and an electric energy transmission aluminum piece 4, and a section of the aluminum conductor 2 with the insulating layer 3 stripped is coated in the electric energy transmission aluminum piece 4 to form a connecting piece; the end part of the copper terminal 1, which is used for being welded with the connecting piece, is provided with a welding platform 11, and a transition layer 12 formed by metal atoms mutually permeating or combined with the metal atoms is formed between the welding platform 11 and the connecting piece.

Compound power transmission system of copper aluminium, electric energy transmission aluminium alloy parcel the aluminium conductor forms the connecting piece, simple structure, electric energy transmission aluminium alloy processing is easier, can greatly improve the production efficiency of power transmission aluminium alloy, reduces the cost of manufacture of compound power transmission system of copper aluminium.

pre-assembling: sleeving the aluminum conductor 2 with the insulating layer 3 stripped into an electric energy transmission aluminum piece 4, and pressing the aluminum conductor 2 with the insulating layer 3 stripped into the electric energy transmission aluminum piece 4 by using a pressing device to form a connecting piece;

clamping: clamping a copper terminal 1 with a welding platform in a rotary fixture of friction welding equipment, and installing the connecting piece subjected to the pre-installation step in a movable fixture;

a welding step: copper terminal is rotatory under rotatory anchor clamps drive, and rotatory anchor clamps's rotational speed is 1000R Min, it drives to remove anchor clamps connecting piece horizontal migration extrudees to rotatory copper terminal, and the pressure that removes anchor clamps is 10000N, is in through the frictional heating connecting piece front end forms the melting layer, then makes under the pressure the melting layer cladding is in on the welded platform 11 of 1 welding end of copper terminal to form with welded platform 11 and use metal atom infiltration or the transition layer 12 of inter combination mutually.

The purpose of this example is to demonstrate the effect of the ratio of different copper-aluminum solid solutions in the transition layer on the drawing force and voltage drop of the copper-aluminum composite electric energy transmission system, and examine the drawing force value, voltage drop value and welding strength of the copper-aluminum composite electric energy transmission system of the ratio of different copper-aluminum solid solutions in the transition layer, and see table 5 for the results.

Table 5 influence of the ratio of cu-al solid solution in the transition layer on the drawing force and voltage drop of cu-al composite power transmission system

From the above table, it can be seen that, when the copper-aluminum solid solution contained in the transition layer is less than 10 wt%, the drawing force of the copper-aluminum composite electric energy transmission system is gradually reduced, the voltage drop of the copper-aluminum composite electric energy transmission system is gradually increased, and the mechanical property and electrical property requirements of the copper-aluminum composite electric energy transmission system cannot be met. Along with the gradual increase of the proportion of the copper-aluminum solid solution contained in the transition layer, the mechanical property and the electrical property of the copper-aluminum composite electric energy transmission system are gradually enhanced, so that the transition layer contains not less than 10 wt% of the copper-aluminum solid solution.

Example 7

As shown in fig. 5, a copper-aluminum composite electric energy transmission system includes a copper terminal 1 and an aluminum cable 6, the aluminum cable includes an aluminum conductor, an insulating layer 3 coated on the periphery of the aluminum conductor, a shielding layer 8 coated on the periphery of the insulating layer 3 and used for shielding electromagnetic interference, and an outer insulating layer 31 coated on the periphery of the shielding layer 8. The connector also comprises an electric energy transmission aluminum piece 4, wherein a section of aluminum conductor 2 with an insulating layer 3 stripped off is wrapped in the electric energy transmission aluminum piece 4 to form a connecting piece; the end part of the copper terminal 1, which is used for being welded with the connecting piece, is provided with a welding platform 11, and a transition layer 12 formed by metal atoms mutually permeating or combined with the metal atoms is formed between the welding platform 11 and the connecting piece.

The purpose of this embodiment is to demonstrate the influence of copper terminals with different metal coatings on the drawing force and voltage drop of a copper-aluminum composite power transmission system, and examine the drawing force value, voltage drop value and welding strength of the copper-aluminum composite power transmission system made of copper terminals with different metal coatings after a salt spray experiment for 48 hours in the copper-aluminum composite power transmission system, and see table 6 for the results.

TABLE 6 influence of different metal coating materials on the performance of copper-aluminum composite electric energy transmission system

From the above table, after a salt spray experiment for 48 hours, the drawing force of the electrical joint of the copper-aluminum composite power transmission system without the anti-corrosion protection layer is obviously reduced, the voltage drop is obviously increased, and the requirements that the drawing force of the copper-aluminum composite power transmission system is larger than 2000N and the voltage drop is below 0.5mV cannot be better met. And other copper-aluminum composite electric energy transmission systems with anti-corrosion protective layers, the drawing force and the voltage drop of the copper-aluminum composite electric energy transmission system still meet the mechanical property and the electrical property requirements of the copper-aluminum composite electric energy transmission system after the test, so that the utility model discloses the people sets for the material of the anti-corrosion protective layer to contain at least one of nickel, cadmium, zirconium, chromium, cobalt, manganese, aluminum, tin, titanium, zinc, copper, silver or gold.

Example 8

According to the steps of the above embodiment 1, the copper-aluminum welding terminal is manufactured, in this embodiment, in order to demonstrate the influence of the thickness of the transition layer on the drawing force, the voltage drop and the welding strength of the copper-aluminum composite electric energy transmission system, the utility model discloses a drawing force value, the voltage drop value and the welding strength of the copper-aluminum composite electric energy transmission system with different thickness transition layers are examined, and the results are shown in table 7.

Table 7: influence of different thicknesses of copper-aluminum transition layers on drawing force and voltage drop of copper-aluminum composite electric energy transmission system

The results in table 7 show that: when the thickness of the copper-aluminum transition layer is less than 0.01 mu m, the drawing force value of the copper-aluminum composite electric energy transmission system is obviously reduced, the voltage drop value of the copper-aluminum composite electric energy transmission system is obviously increased, and the mechanical property and the electrical property of the obtained copper-aluminum composite electric energy transmission system are poor. Moreover, after the salt spray experiment, the mechanical property and the electrical property of the copper-aluminum composite electric energy transmission system are reduced more, so that the performance and the service life of the copper-aluminum composite electric energy transmission system are greatly reduced.

When the thickness of copper aluminium transition layer is greater than 6000 mu m, the mechanical properties and the electrical properties of copper aluminium composite power transmission system have appeared the decline trend, and correspondingly, in order to obtain the copper aluminium transition layer that thickness is greater than 6000 mu m, the pressure and the time that equipment was applyed increase substantially, consequently, utility model people select the thickness of copper aluminium transition layer to be 0.01 mu m ~ 6000 mu m.

Example 9

The processing method of the copper-aluminum composite electric energy transmission system in the above embodiment further includes the welding platform manufacturing step: and processing a welding platform on the end face of the copper terminal by using a mechanical processing device.

Further, the adopted machining device can be a turning device, and before welding, a turning tool on the turning device is used for turning the welding platform on the end face of the rotating copper terminal.

Furthermore, the adopted machining device can be a milling device, and before welding, a milling cutter on the milling device is used for milling the end face of the fixed copper terminal to form a welding platform.

Furthermore, the adopted machining device can be a saw cutting device, and before welding, a saw blade on the saw cutting device is used for saw cutting a welding platform on the end face of the fixed copper terminal.

Further, the adopted machining device can be a grinding device, and before welding, a grinding wheel on the grinding device is used for grinding the end face of the fixed copper terminal to form a welding platform.

Furthermore, the adopted machining device can be a planing device, and a planing tool on the planing device is used for planing the end face of the fixed copper terminal to form a welding platform before welding.

The machining device of the present invention includes but is not limited to the above machining device and machining method.

The above embodiments are only preferred embodiments of the present invention, and the protection scope of the present invention cannot be limited thereby, and any insubstantial changes and substitutions made by those skilled in the art based on the present invention are all within the protection scope of the present invention.

Claims

1. A copper-aluminum composite electric energy transmission system comprises a copper terminal and an aluminum cable, wherein the aluminum cable comprises an aluminum conductor and an insulating layer coated on the periphery of the aluminum conductor; the end part of the copper terminal, which is used for being welded with the connecting piece, is provided with a welding platform, and a transition layer which is formed by mutually permeating metal atoms or mutually combining the metal atoms is formed between the welding platform and the connecting piece.

2. The copper-aluminum composite electrical energy transmission system of claim 1, wherein the front end of the connector has a melted layer.

3. The copper-aluminum composite power transmission system of claim 2, wherein the melt layer forms an extended cladding layer around the end surface of the soldering platform in the direction of the copper terminal.

4. The copper-aluminum composite electrical energy transmission system of claim 3, wherein the extension cladding is clad to at least the copper terminal end.

5. The copper-aluminum composite electrical energy transmission system of any one of claims 2-4, wherein the thickness of the molten layer is 0.01cm-15 cm.

6. The copper-aluminum composite power transmission system of claim 1, wherein the welding platform includes an end surface welded to the connector and a root connected to the copper terminal end, the end surface having a cross-sectional area smaller than a cross-sectional area of the root.

7. The copper-aluminum composite power transmission system of claim 1, wherein the cross-sectional area of the end face of the weld platform is at least 50% of the cross-sectional area of the root.

8. The copper-aluminum composite power transmission system of claim 1, wherein the soldering platform height is 0.01cm-15 cm.

9. The copper-aluminum composite power transmission system of claim 1, wherein the transition layer has a thickness of 0.01 μ ι η to 6000 μ ι η.

10. The copper-aluminum composite electrical energy transmission system of claim 1, wherein a surface of the copper terminal is provided with a metal plating.

11. The copper-aluminum composite power transmission system of claim 1, wherein the aluminum cable further comprises a shielding layer wrapped around the insulating layer for shielding electromagnetic interference.