Patent Description:
Copper or copper alloy is widely used in the field of electrical connections due to its good electrical conductivity, thermal conductivity, and plasticity. However, there is a shortage of copper resources, and the content of copper in the earth's crust is only about <NUM>%. With the increase of the usage time, the cost of copper will rise year by year. Therefore, people begin to look for alternatives for metal copper to reduce the cost.

The content of metal aluminum in the earth's crust is about <NUM>%. With the refining technology of aluminum being optimized, the price of aluminum is relatively low. Aluminum also has excellent electrical conductivity, thermal conductivity, and plastic workability. Therefore, it is a main development trend at present to replace copper with aluminum in the field of automobile electrical connections.

Compared with copper, aluminum has slightly lower hardness, plasticity and corrosion resistance, but its weight is lighter, and its conductivity ranks only second to that of copper. Thus, aluminum can partially replace copper in the field of electrical connections. However, due to a large electrode potential difference between copper and aluminum, an electrochemical corrosion will occur between the directly connected copper and aluminum, such that aluminum is susceptible to the corrosion and a resistance in the connection area may increase, which will easily lead to serious consequences such as functional failures and fires in the electrical connections.

In order to solve the problem of electrochemical corrosion caused by the direct contact between copper and aluminum, Chinese invention patent <CIT> discloses a copper-aluminum joint, including an aluminum wire, an aluminum tube, a copper wiring terminal, and a welding layer. The aluminum wire includes a wire harness and an insulation layer wrapping the wire harness. The aluminum wire is sleeved by the aluminum tube which has one end located on a wire harness (i.e. a lead) removed of the insulation layer at an end portion of the aluminum wire, and the other end located on an adjacent insulation layer. The inner wall of the aluminum tube is stepped, with an inner stepped surface matched with an end surface of the insulation layer. The welding layer is located between the aluminum wire and the copper terminal. The processing method thereof is to use the aluminum tube with an inner stepped surface to crimp the lead and the insulation layer of the aluminum wire, respectively, then connect the aluminum tube and the copper terminal by friction welding, and finally seal with a heat-shrinkable tube.

Crimping both the lead and the insulation layer of the aluminum wire in the aluminum tube has the following disadvantages.

Patent application <CIT> discloses a compression connecting terminal for conductor, including a compression connecting cylindrical body part which is connected to a conductor inserted thereto by compression, and a fastening terminal part connected to the cylindrical body part. The cylindrical body part has a thickness gradually increased or decreased in the longitudinal direction.

Patent application <CIT> discloses a quick connector, including a male connector and a female connector. The front part of the male connector is a conical joint composed of a number of elastic compression pieces with external threads. There is a gap between each two compression pieces, one end of the elastic compression piece is vacant, and the other end thereof is connected to the rear cylinder of the male connector. An inner cavity of the female connector is equipped with a conical female threaded hole which is compatible with the conical joint. The outer diameter of the female connector is the same as the outer diameter of the rear cylinder of the male connector. The rear cylinder of the male connector is also provided with a block on the inner side. The outer side of the end of the female connector and the outer side of the rear cylinder of the male connector are provided with a heat-shrinkable tube jam. The outer sides of the female connector and the male connector are equipped with a heat-shrinkable tube.

Patent application <CIT> discloses a terminal connection structure, including a terminal member and a cylindrical body. The cylindrical body is fitted externally to an end part of the wire to integrate the cylindrical body with the end part. End faces of the wire and the cylindrical body are machined flush to form a connecting surface to be jointed with a terminal connecting surface of the terminal member.

In order to overcome the disadvantages of the prior art, the present disclosure provides an electric energy transmission aluminum part, which not only avoids an insulation layer from being crimped into a lead portion and increasing a resistance of the lead portion, but also prevents an indentation from being formed on a surface of the insulation layer and causing breakdown, and further reduces an interference with a mating end environment, thus achieving a wider application range. The present disclosure further provides an aluminum connector with the electric energy transmission aluminum part, and a copper-aluminum joint with the aluminum connector. In addition, the copper-aluminum joint can also reduce processing working hours, reduce material waste and save resources.

Any references to inventions or embodiments not falling within the scope of the independent claims are to be interpreted as examples useful for understanding the invention.

Compared with the prior art, the present disclosure has the following advantageous effects.

+- In the electric energy transmission aluminum part according to the present disclosure, the aluminum body is internally provided with a conical insertion hole. During use, a section of the aluminum conductor stripped of the insulation layer in the aluminum cable is inserted in the conical insertion hole with the maximum diameter end adjacent to the insulation layer. When the conical insertion hole is crimped with the aluminum cable, the maximum diameter end of the conical insertion hole is subjected to stress and expanded outwards at a certain angle to be far away from the aluminum conductor and the insulation layer, which on the one hand reduces the possibility of sharp cutting of the aluminum conductor by the electric energy transmission aluminum part, and on the other hand prevents a resistance of a lead portion from being increased as the insulation layer is crimped into the lead portion, and further avoids breakdown caused by an indentation formed on the surface of the insulation layer. Meanwhile, it is unnecessary to increase the length of the electric energy transmission aluminum part, thereby reducing the interference with the mating end environment and extending the application range. Moreover, the conical structure insertion hole is beneficial to reducing the resistance to the insertion of the aluminum conductor.

The aluminum body with a conical structure is beneficial to reducing the resistance to the insertion of the aluminum conductor. In addition, the conical structure facilitates a tighter crimping of the front end of the aluminum connector. The length of the electric energy transmission aluminum part allows the stress of the aluminum conductor to be effectively released during the crimping process, so as to effectively avoid the longitudinal cutting of the aluminum cable at the crimped end.

The aluminum body with a columnar structure is convenient to be clamped by a fixture to apply stress without damaging the aluminum conductor. Compared with the monofilament-stranded structure of the aluminum conductor, the aluminum body, as a solid columnar structure, is not easy to be damaged and has greater welding strength, larger welding surface, and better welding performance.

The aluminum body with a cylindrical structure is beneficial to uniformly receiving the external stress during welding and clamping.

A limiting platform is provided at the maximum diameter end of the conical insertion hole to prevent the insulation layer of the aluminum cable from entering the conical insertion hole, which can effectively limit an insertion amount of the aluminum conductor, realize a standardized operation, and further effectively prevent the insulation layer of the aluminum cable from participating in the crimping, thus avoiding the risk of breakdown.

The aluminum body of the electric energy transmission aluminum part partially acts as a conductor when being crimped with the aluminum cable to form the aluminum connector, thus increasing the conductivity of the aluminum connector.

The copper-aluminum joint may further include a heat-shrinkable tube which clads a connecting position of the copper terminal and the aluminum connector. After the welding is completed, the non-sealed or non-vacuum use area is sealed with the heat-shrinkable tube, which on the one hand avoids the copper terminal and the aluminum cable from being corroded by external media, and on the other hand prevents the aluminum cable from being bent or even broken due to local stress.

Reference numerals:
<NUM>. aluminum body; <NUM>. conical insertion hole; <NUM>. aluminum conductor; <NUM>. insulation layer; <NUM>. chamfered structure; <NUM>. limiting platform.

In order to further explain the technical means adopted by the present disclosure to achieve the intended invention objective and effects thereof, the specific implementations, structures, characteristics and effects of the present disclosure will be described in detail below with reference to the drawings and the exemplary embodiments.

As illustrated in <FIG>, an aluminum connector with an electric energy transmission aluminum part of a first embodiment according to the present disclosure includes an aluminum body <NUM> and an aluminum cable. The aluminum cable includes an aluminum conductor <NUM> and an insulation layer <NUM> cladding a periphery of the aluminum conductor <NUM>. The aluminum body is internally provided with a conical insertion hole <NUM> penetrating through front and rear ends thereof. The conical insertion hole is provided with a maximum diameter end and a minimum diameter end. During use, a section of the aluminum conductor stripped of the insulation layer in the aluminum cable is inserted in the conical insertion hole with the maximum diameter end adjacent to the insulation layer. When the conical insertion hole is crimped with the aluminum cable to form the aluminum connector, the maximum diameter end of the conical insertion hole is subjected to stress and expanded outwards at a certain angle to be far away from the aluminum conductor and the insulation layer, which on the one hand reduces the possibility of sharp cutting of the aluminum conductor by the electric energy transmission aluminum part, and on the other hand prevents a resistance of the aluminum conductor from being increased as the insulation layer is crimped into the lead portion, and further avoids breakdown caused by an indentation formed on the surface of the insulation layer. Meanwhile, it is unnecessary to increase the length of the electric energy transmission aluminum part, thereby reducing the interference with the mating end environment and extending the application range.

The aluminum body is of a conical structure, which is beneficial to reducing the resistance to the insertion of the aluminum conductor. In addition, the conical structure facilitates a tighter crimping of the front end of the aluminum connector. The length of the electric energy transmission aluminum part allows the stress of the aluminum conductor to be effectively released during the crimping process, so as to effectively avoid the longitudinal cutting of the aluminum cable at the crimped end.

The aluminum body has a uniform wall thickness.

The aluminum connector may be adopted to manufacture a copper-aluminum joint, which is structurally composed of a copper terminal and the aluminum connector. The copper terminal is connected to the aluminum connector, between which a transition layer with metal atoms penetrating into or combined with each other is formed.

The transition layer with metal atoms penetrating into or combined with each other is formed between the copper terminal and the aluminum connector by friction welding, laser welding, resistance welding, pressure welding, ultrasonic welding, or arc welding.

The copper-aluminum joint further includes a heat-shrinkable tube which clads a connecting position of the copper terminal and the aluminum connector. The heat-shrinkable tube is used to directly seal the electric energy transmission aluminum part and the insulation layer, and it is unnecessary to crimp the insulation layer with the aluminum tube and then seal them with the heat-shrinkable tube as in the prior art, thus saving working hours and resources. Moreover, after the welding is completed, the non-sealed or non-vacuum use area is sealed with the heat-shrinkable tube, which on the one hand avoids the copper terminal and the aluminum cable from being corroded by external media, and on the other hand prevents the aluminum cable from being bent or even broken due to local stress.

An aluminum connector with an electric energy transmission aluminum part of a second embodiment according to the present disclosure differs from the first embodiment illustrated in <FIG> in that the maximum diameter end of the conical insertion hole is provided with a chamfered structure <NUM>. Specifically, as illustrated in <FIG>, the chamfered structure <NUM> is provided at an inner side of the maximum diameter end, which can effectively reduce the impact on the aluminum cable. Alternatively, the chamfered structure is provided at an outer side of the maximum diameter end, which can effectively avoid the influence of the sharp corner of the conical insertion hole on the external environment. Alternatively, as illustrated in <FIG>, the inner side and the outer side of the maximum diameter end are provided with the chamfered structure <NUM> respectively.

As illustrated in <FIG>, an aluminum connector with an electric energy transmission aluminum part of a third embodiment according to the present disclosure only differs from the aluminum connector illustrated in <FIG> in that the aluminum body <NUM> has a different shape. In this embodiment, the aluminum body <NUM> is of a columnar structure, which is convenient to be clamped by a fixture to apply a stress without damaging the aluminum conductor. Compared with the monofilament-stranded structure of the aluminum conductor, the aluminum body, as a solid columnar structure, is not easy to be damaged and has greater welding strength, larger welding surface, and better welding performance. As a further exemplary solution of this embodiment, the aluminum body <NUM> is of a cylindrical structure, which is beneficial to uniformly receiving the external stress during welding and clamping.

The aluminum body has a non-uniform wall thickness.

The transition layer with metal atoms penetrating into or combined with each other is formed between the copper terminal and the aluminum connector by friction welding, laser welding, resistance welding, pressure welding, ultrasonic welding or arc welding.

As illustrated in <FIG>, an aluminum connector with an electric energy transmission aluminum part of a fourth embodiment according to the invention only differs from the aluminum connector illustrated in <FIG> in that the aluminum body <NUM> has a different shape. In this embodiment, the aluminum body <NUM> is provided with a limiting platform <NUM> at the maximum diameter end of the conical insertion hole, which can effectively limit an insertion amount of the aluminum conductor, realize a standardized operation, and effectively prevent the insulation layer of the aluminum cable from participating in the crimping, thus avoiding the risk of breakdown.

Meanwhile, if there is a plastic connector that needs to be plugged in, this limiting platform may be taken as a positioning point for effective mounting.

Claim 1:
An electric energy transmission aluminum part, comprising an aluminum body (<NUM>) internally provided with a conical insertion hole (<NUM>) which penetrates through front and rear ends thereof, with the conical insertion hole (<NUM>) being provided with a maximum diameter end and a minimum diameter end;
characterized in that
the maximum diameter end of the conical insertion hole (<NUM>) is provided with a limiting platform (<NUM>), the limiting platform (<NUM>) is extended outward in a radial direction from said conical insertion hole (<NUM>), and the limiting platform (<NUM>) protrudes out of an outer surface of the aluminum body (<NUM>).