Connector dissimilar metal anti-corrosion connection method and electric transmission system

Abstract

The invention relates to the technical field of electric transmission, and provides a connector dissimilar metal anti-corrosion connection method and an electric transmission system. Each wire comprises an insulating wrapping layer and a wire core, and each wire core comprises a plurality of metal wires; the method comprises the following steps: dipping a soldering flux on the surface of a connecting part of a metal wire, and plating a first anti-oxidation layer on the surface of the connecting part of the metal wire by using hot dipping, so that the connecting part covered with the first anti-oxidation layer is connected with other wires; wherein the connecting part of the metal wire is exposed after the insulating cladding at the position to be connected of the wire is stripped. Compared with the prior art in which the whole metal wire is plated, the anti-oxidation layer is plated on the connecting part of the metal wire, so that the cost can be greatly reduced, and moreover, as electrochemical corrosion mainly occurs on the connecting part, a good anti-corrosion effect can still be realized while the cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical transmission, and in particular to a method for anti-corrosion connection of dissimilar metals in a connector and an electrical transmission system. Background Art

[0002] In a photovoltaic system, copper wires and aluminum wires are often electrically connected through a connector. However, the direct contact between the two will cause electrochemical corrosion due to the potential difference. Especially in a humid environment, the corrosion rate increases significantly, resulting in an increase in contact resistance, and risks of heating and even fire. In the prior art, the methods for isolating moisture mainly include: using a copper-aluminum connector or using a silicone seal to prevent moisture from penetrating, etc. Among them, using a copper-aluminum connector will increase the contact resistance, thus causing power loss. The silicone seal method often cannot achieve complete sealing and cannot fundamentally solve the corrosion problem.

[0003] In view of this, overcoming the defects of the existing technology is an urgent problem to be solved in this technical field. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for anti-corrosion connection of dissimilar metals in a connector and an electrical transmission system.

[0005] The present invention adopts the following technical solutions:

[0006] In the first aspect, the present invention provides a method for anti-corrosion connection of dissimilar metals in a connector. The wire includes an insulating sheath and a wire core, and the wire core includes a plurality of metal wires; the method includes:

[0007] Impregnate a flux on the surface of the connection part of the metal wires, and use hot dip plating to coat a first antioxidant layer on the surface of the connection part of the metal wires, so as to connect the connection part covered with the first antioxidant layer to other wires;

[0008] Wherein, the connection part of the metal wires is exposed after stripping the insulating sheath at the connection position of the wire.

[0009] Preferably, the method further includes:

[0010] Coat a protective metal with a first thickness on the surface of the terminal of the connector to obtain a second antioxidant layer.

[0011] Preferably, the method further includes:

[0012] Keep the crimping part of the terminal in the electroplating solution to increase the thickness of the protective metal with a second thickness, so as to increase the thickness of the second antioxidant layer of the crimping part and provide a loss space for the terminal crimping process.

[0013] Preferably, when crimping the metal wire in the wire to the terminal of the connector, the crimping pressure used is 5 to 200 MPa, and the crimping holding time used is 1 to 3 s.

[0014] Preferably, before plating the first antioxidant layer on the surface of the connection part of the metal wire, the method further includes:

[0015] Using a preset clamp to extrude and shape the wire core to shape the wire core into a preset shape, maintaining the preset shape for subsequent hot dip plating operations, so that after plating the first antioxidant layer, the overall shape of the wire core matches the shape after crimping with the terminal;

[0016] Wherein, the preset shape is a shape with a notch at the center position of the wire core, and the notch is used to provide a reserved space for the crimping of the terminal to reduce the loss of the first antioxidant layer during the terminal crimping process.

[0017] Preferably, the preset clamp includes a first clamp body 1, a second clamp body 2 and a connecting shaft 3; the first clamp body 1 and the second clamp body 2 are connected by the connecting shaft 3, the first clamp body 1 includes a first clamp handle 11 and a first clamp jaw 12, and the second clamp body 2 includes a second clamp handle 21 and a second clamp jaw 22;

[0018] A receiving opening 121 is provided on the first clamp jaw 12 for receiving the wire core;

[0019] A protrusion 221 is provided at the center position of the second clamp jaw 22 corresponding to the receiving opening 121. The protrusion 221 is used to squeeze the metal wire of the wire core to both sides of the receiving opening 121 when the first clamp handle 11 and the second clamp handle 21 are squeezed, so that the wire core forms the preset shape.

[0020] Preferably, the protrusion 221 includes a vertex angle 2210 facing the bottom of the receiving opening 121 and a first arc-shaped surface 2211 and a second arc-shaped surface 2212 respectively located on both sides of the vertex angle 2210;

[0021] Both the first arc-shaped surface 2211 and the second arc-shaped surface 2212 are bent in the reverse direction of the receiving opening 121, so that when the first clamp handle 11 and the second clamp handle 21 are squeezed, the metal wires arranged around the vertex angle 2210 slide to both sides of the receiving opening 121 along the first arc-shaped surface 2211 or the second arc-shaped surface 2212.

[0022] Preferably, when the number of metal wires included in the wire is 13 and the radius of each metal wire is r, the receiving opening 121 is an arc with a radius of and the radian angle of the arc is greater than or equal to 210°.

[0023] Preferably, the width of the receiving opening 121 matches the inner diameter of the wire, and the height of the receiving opening 121 is less than the inner diameter of the wire.

[0024] In a second aspect, the present invention provides an electrical transmission system, in which each wire in the electrical transmission system is connected using the method for preventing corrosion of dissimilar metals in connectors described in the first aspect.

[0025] By plating an antioxidant layer on the connection part of the metal wire, compared with the prior art of plating the entire metal wire, the present invention can greatly reduce the cost. And since electrochemical corrosion mainly occurs at the connection part, the present invention can still achieve a good anti-corrosion effect while reducing the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments of the present invention. Obviously, the following described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 is a cross-sectional schematic diagram of a wire provided by an embodiment of the present invention;

[0028] Figure 2 is a flowchart schematic diagram of a method for preventing corrosion of dissimilar metals in connectors provided by an embodiment of the present invention;

[0029] Figure 3 is a flowchart schematic diagram of a method for preventing corrosion of dissimilar metals in connectors provided by an embodiment of the present invention;

[0030] Figure 4 is a schematic diagram of the state change of a terminal in a method for preventing corrosion of dissimilar metals in connectors provided by an embodiment of the present invention;

[0031] Figure 5 is a schematic diagram of a terminal in a method for preventing corrosion of dissimilar metals in connectors provided by an embodiment of the present invention;

[0032] Figure 6 is a schematic diagram during the crimping process of a wire and a terminal in a method for preventing corrosion of dissimilar metals in connectors provided by an embodiment of the present invention;

[0033] Figure 7 is a flowchart schematic diagram of a method for preventing corrosion of dissimilar metals in connectors provided by an embodiment of the present invention;

[0034] Figure 8Cross-sectional schematic diagram of a wire after being plastically deformed by a preset fixture in a method for preventing corrosion in the connection of dissimilar metals of a connector provided by an embodiment of the present invention;

[0035] Figure 9 Cross-sectional schematic diagram of a wire after being plated with a first antioxidant layer after being plastically deformed by a preset fixture in a method for preventing corrosion in the connection of dissimilar metals of a connector provided by an embodiment of the present invention;

[0036] Figure 10 Structural schematic diagram of a preset fixture in a method for preventing corrosion in the connection of dissimilar metals of a connector provided by an embodiment of the present invention;

[0037] Figure 11 Partial structural schematic diagram of a preset fixture in a method for preventing corrosion in the connection of dissimilar metals of a connector provided by an embodiment of the present invention;

[0038] Figure 12 Partial structural schematic diagram of a preset fixture in a method for preventing corrosion in the connection of dissimilar metals of a connector provided by an embodiment of the present invention;

[0039] Figure 13 Partial structural schematic diagram of a preset fixture in a method for preventing corrosion in the connection of dissimilar metals of a connector provided by an embodiment of the present invention;

[0040] Figure 14 Partial structural schematic diagram of a preset fixture in a method for preventing corrosion in the connection of dissimilar metals of a connector provided by an embodiment of the present invention;

[0041] Figure 15 Architectural schematic diagram of a device for preventing corrosion in the connection of dissimilar metals of a connector provided by an embodiment of the present invention;

[0042] Figure 16 Architectural schematic diagram of a device for preventing corrosion in the connection of dissimilar metals of a connector provided by an embodiment of the present invention.

[0043] In all the drawings, the same reference numerals are used to represent the same elements or structures, where:

[0044] 1. First pliers body; 11. First pliers handle; 12. First pliers jaw; 121. Accommodating opening; 1210. First accommodating opening; 1211. Second accommodating opening; 1212. Third accommodating opening; 1213. Fourth accommodating opening; 1214. Fifth accommodating opening; 2. Second pliers body; 21. Second pliers handle; 22. Second pliers jaw; 221. Protrusion; 2210. Vertex angle; 2211. First arc-shaped surface; 2212. Second arc-shaped surface; 2213. First protrusion; 2214. Second protrusion; 2215. Third protrusion; 2216. Fourth protrusion; 2217. Fifth protrusion; 3. Connecting shaft. Detailed implementation manners

[0045] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0046] Unless otherwise required by the context, throughout the specification and claims, the term "comprising" is interpreted in an open, inclusive sense, i.e., "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "examples", "specific examples" or "some examples", etc., are intended to indicate that the specific features, structures, materials or characteristics related to the embodiment or example are included in at least one embodiment or example of the present disclosure. The schematic representations of the above terms do not necessarily refer to the same embodiment or example. In addition, the specific features, structures, materials or characteristics may be included in any one or more embodiments or examples in any appropriate manner, that is, although they may be carried in the embodiments or examples of the above terms due to reasons such as the order and position of appearance, however, it does not limit that they can be carried by one embodiment or example in a combined manner.

[0047] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present disclosure.

[0048] In the description of the present invention, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present disclosure, unless otherwise stated, the meaning of "a plurality" is two or more. In addition, for example, in the description, for the same type of nouns, the method of adding "A" and "B" at the end is used to describe them as two independent individuals. In this case, the features defined with "A" and "B" are only used for the purpose of distinguishing similar individuals and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features.

[0049] In describing some embodiments, the expressions "coupled", "coupling", "connected" and their derivatives may be used. For example, in describing some embodiments, the term "connected" may be used to indicate that two or more components have direct physical or electrical contact with each other. Another example is that in describing some embodiments, the term "coupled" may be used to indicate that two or more components have direct physical or electrical contact. However, the term "connected" or "coupled" may also mean that two or more components do not have direct contact with each other, but still cooperate or interact with each other, such as "optical path coupling", "wireless connection", etc. The embodiments disclosed herein are not necessarily limited to the content of the present invention.

[0050] In the description of the present invention, the expression "A and / or B" (where A and B are used to formally represent specific feature contents) includes the following three combinations: only A, only B, and the combination of A and B.

[0051] As used in the present invention, "about", "substantially" or "approximately" includes the stated value and the average value within an acceptable deviation range of the specific value, where the acceptable deviation range is determined by those of ordinary skill in the art considering the measurement being discussed and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system).

[0052] In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0053] Embodiment 1:

[0054] In the prior art, there is a method of electroplating an antioxidant coating on the surface of a metal wire to prevent corrosion, but usually an antioxidant coating is electroplated on the entire metal wire. This method is too costly, and for the scenario of large-scale use of wires, it will cause a sharp increase in cost. To solve this problem, Embodiment 1 of the present invention provides a method for anti-corrosion connection of dissimilar metals of a connector, as Figure 1 shown, the wire includes an insulating cladding and a wire core, and the wire core includes a plurality of metal wires; as Figure 2 shown, the method includes:

[0055] In step 201, a soldering flux is impregnated on the surface of the connection portion of the metal wire.

[0056] In step 202, a first antioxidant layer is plated on the surface of the connection portion of the metal wire by hot dip plating, so that the connection portion covered with the first antioxidant layer is connected to other wires.

[0057] Wherein, the connection portion of the metal wire is exposed after stripping the insulating cladding at the connection position of the wire. The metal wire can be an aluminum wire or a copper wire, and the material of the first antioxidant layer can be tin or nickel.

[0058] In an alternative embodiment, it may be: when it is necessary to connect a wire to a wire of other dissimilar metals, first strip about 6 mm of the insulating sheath at the end of the wire to expose the wire core, that is, multiple metal wires, and then tin or nickel plate the metal wires of the exposed part according to the method described in steps 201-step 202.

[0059] In this embodiment, by plating an anti-oxidation layer on the connection part of the metal wires, compared with the prior art of plating the entire metal wire, the cost can be greatly reduced. And since electrochemical corrosion mainly occurs at the connection part, this embodiment can still achieve a good anti-corrosion effect while reducing the cost.

[0060] Moreover, this embodiment selects the hot-dip plating method for plating, so that a thicker anti-oxidation layer can be plated relative to the electroplating method in the prior art. On this basis, this embodiment also provides a preferred embodiment, that is, the thickness of the first anti-oxidation layer is greater than 100 nm. While the thickness of the electroplated anti-oxidation coating in the prior art is often less than 10 nm, and this embodiment can provide a better anti-corrosion effect by hot-dip plating a thicker anti-oxidation layer.

[0061] In the above embodiment, this embodiment plates a first anti-oxidation layer on the connection part of the metal wires. In actual use, two wires usually need to be connected through a connector, that is, each wire is crimped to the corresponding terminal in the connector. Considering that the terminal may also be corroded, this embodiment also plates a protective metal with a first thickness on the surface of the terminal of the connector. Considering the loss of the protective metal during the crimping process, this embodiment also provides a preferred embodiment, as Figure 3 shown, the method further includes:

[0062] In step 301, plate a protective metal with a first thickness on the surface of the terminal of the connector to obtain a second anti-oxidation layer.

[0063] In step 302, keep the crimping part of the terminal in the electroplating solution to electroplate an additional protective metal with a second thickness to increase the thickness of the second anti-oxidation layer of the crimping part and provide a loss space for the terminal crimping process; that is, considering the possible loss of the protective metal during the terminal crimping process, the protective metal of the crimping part is thickened.

[0064] Wherein, the second anti-oxidation layer includes a protective metal with a first thickness and a protective metal with a second thickness.

[0065] Wherein, multiple wires are connected through a connector, and the connector may be a photovoltaic connector, such as MC4 (fully called: Multi-Contact 4mm 2)Photovoltaic connector. The connector includes terminals and a housing. The terminals are used to be crimped with the wire cores to connect two wires. The part of the terminal used to be crimped with the wire cores is the crimping part of the terminal. The housing is used to be arranged on the outer periphery of the terminals to play a protective role. The protective metal has the same material as the first antioxidant layer, and can be tin or nickel.

[0066] The changes of the terminals before and after the execution of the method described in the above step 301-step 302 are as Figure 4 shown. Figure 4 In (a), it is the terminal before the execution of step 301; in (b), it is the terminal after the execution of step 301, that is, a protective metal is plated on the surface of the terminals of the connector; in (c), it is the terminal after the execution of step 302, that is, the protective metal is only continuously plated on the crimping part. Figure 4 The enlarged schematic diagram of the crimping part of the terminal in (c) in Figure 5 is shown. Among them, L1 is the thickness of the second antioxidant layer in the crimping part (that is, the first thickness plus the second thickness), and L2 is the thickness of the second antioxidant layer in the non-crimping part (that is, the first thickness). It can be seen that L1 is greater than L2. The first thickness and the second thickness are obtained by those skilled in the art through empirical analysis.

[0067] In this embodiment, a thicker antioxidant layer is additionally plated on the crimping part of the terminal, so as to ensure the thickness of the antioxidant layer retained after the terminal is crimped and ensure the anti-corrosion effect.

[0068] In an alternative embodiment, when crimping the metal wires in the wire with the terminals of the connector, the crimping pressure used is 5-200 MPa, and the crimping holding time used is 1-3 s.

[0069] In actual use, due to the particularity of the photovoltaic system, most of its wires and connectors need to be installed outdoors and are even directly exposed to the natural environment. Moreover, for the stability of the photovoltaic system, the wires and connectors often need to be used for a long time. However, during long-term use in the harsh outdoor environment, the antioxidant layer usually gradually wears out, resulting in the weakening of its corrosion resistance and even the loss of corrosion resistance. In addition, due to the degradation of the antioxidant layer, gaps appear between the metal wire and the terminal, which also increases the impedance at the connection position, thereby increasing power loss and further affecting the stability of the photovoltaic system. Therefore, in order to ensure the long-term stable use of the photovoltaic system, higher requirements need to be put forward for the thickness and firmness of the antioxidant layer. In the above method of this embodiment, a series of improvements have been made to the thickness of the antioxidant layer. However, through actual tests, it is found that during the crimping process of the terminal and the wire core, there is not only the loss caused by crimping wear (this loss can still be compensated by increasing the thickness of the antioxidant layer), but also the situation where the opening and reverse buckle of the terminal directly crush the antioxidant layer. Since the contact area at the opening and reverse buckle position of the terminal is small, it is easy to apply excessive pressure to the antioxidant layer on the surface of the metal wire at this position, resulting in excessive loss of the antioxidant layer at this position and easy to cause gaps in the antioxidant layer. Once gaps appear in the antioxidant layer, moisture in the environment will directly penetrate from the gap position, resulting in the failure of the antioxidant layer and unable to play a good anti-corrosion role, such as Figure 6 is a schematic diagram of the opening and reverse buckle position during the terminal crimping process. It can be seen that the pressure at the opening and reverse buckle position directly acts on the surface of the antioxidant layer of the upper metal wire. To solve this problem, this embodiment also provides a preferred implementation manner. Before plating the first antioxidant layer on the surface of the connection part of the metal wire, such as Figure 7 shown, the method further includes:

[0070] In step 401, a preset clamp is used to extrude and shape the wire core to shape the wire core into a preset shape.

[0071] In step 402, the subsequent hot-dip plating operation is carried out while maintaining the preset shape, so that after the first antioxidant layer is plated, the overall shape of the wire core matches the shape after crimping with the terminal; wherein, the preset shape is a shape with a notch at the center position of the wire core, and the notch is used to provide a reserved space for the crimping of the terminal to reduce the loss of the first antioxidant layer during the terminal crimping process. The preset shape can be as Figure 8 shown. After plating the first antioxidant layer, the notch is still retained, as Figure 9 shown, to match the opening and reverse buckle position of the terminal, thereby reducing the pressure at the opening and reverse buckle position during the crimping process, reducing the loss of the first antioxidant layer on the outer layer of the metal wire at this position, and preventing the first antioxidant layer at this position from having gaps. It should be noted here that Figure 8It is merely a schematic diagram of a preset shape. In actual use, the preset shape is obtained by those skilled in the art through requirement analysis. Any shape with a notch at the center position of the fiber core can be regarded as being within the protection scope of the preset shape.

[0072] As Figure 10 shown, the preset clamp includes a first clamp body 1, a second clamp body 2, and a connecting shaft 3; the first clamp body 1 and the second clamp body 2 are connected by the connecting shaft 3. The first clamp body 1 includes a first clamp handle 11 and a first clamp jaw 12, and the second clamp body 2 includes a second clamp handle 21 and a second clamp jaw 22; the first clamp jaw 12 and the second clamp jaw 22 are matched so that when the preset clamp is tightened, the first clamp jaw 12 and the second clamp jaw 22 are closed and generate opposite-direction acting forces on each other.

[0073] A receiving opening 121 is provided on the first clamp jaw 12 for receiving the wire core; a protrusion 221 is provided at the center position corresponding to the receiving opening 121 on the second clamp jaw 22. The protrusion 221 is used to squeeze the metal wire of the wire core to both sides of the receiving opening 121 when the first clamp handle 11 and the second clamp handle 21 are squeezed, so as to form the preset shape of the wire core. The shape and size of the protrusion 221 are obtained by those skilled in the art through pre-analysis of the size of the wire core in the wire to be matched. As Figure 11 shown, when the preset clamp is tightened, the protrusion 221 enters the inside of the receiving opening 121 and squeezes the internal metal wires, thereby playing a role in plasticizing the metal wires. Here, it should be noted that the process of squeezing and shaping the wire core with the preset clamp is carried out before plating the first antioxidant layer, considering that the metal wire usually has a certain degree of hardness and relatively high integrity compared with the first antioxidant layer, and even if a certain pressure is applied to it, it will not cause damage to it.

[0074] In a preferred embodiment, as Figure 12 shown, the protrusion 221 includes a vertex angle 2210 facing the bottom of the receiving opening 121 and a first arc-shaped surface 2211 and a second arc-shaped surface 2212 respectively located on both sides of the vertex angle 2210; both the first arc-shaped surface 2211 and the second arc-shaped surface 2212 are bent in the reverse direction of the receiving opening 121, so that when the first clamp handle 11 and the second clamp handle 21 are squeezed, the metal wires arranged around the vertex angle 2210 slide to both sides of the receiving opening 121 along the first arc-shaped surface 2211 or the second arc-shaped surface 2212. Among them, Figure 11 is a partial enlarged schematic diagram of the first clamp jaw 12 and the second clamp jaw 22 of the preset clamp in the closed state, Figure 12 is a partial enlarged schematic diagram of the receiving opening 121 and the protrusion 221 of the first clamp jaw 12 and the second clamp jaw 22 of the preset clamp in the closed state.

[0075] Moreover, the width of the receiving opening 121 matches the inner diameter of the wire (i.e., the overall outer diameter of the wire core). It can be that the width of the receiving opening 121 is approximately equal to the inner diameter of the wire, and the height of the receiving opening 121 is less than the inner diameter of the wire. The purpose of such a design is that when the first jaw 12 and the second jaw 22 are closed, the accommodation space in the receiving opening 121 is slightly smaller than the occupied space of the wire core in the relaxed state, thereby generating a small squeezing force on the wire core, causing the metal wires in the wire core to undergo small deformations under the action of the squeezing force, so that after the preset tool is withdrawn, the preset shape can still be maintained. As Figure 13 shown, assuming that the inner diameter of the wire is 2r, then the width W of the receiving opening 121 is approximately equal to 2r, and the height H of the receiving opening 121 is less than 2r.

[0076] In a preferred embodiment, the number of the receiving openings 121 and the protrusions 221 is multiple to support pressing and shaping the wire cores of multiple wires. Moreover, the sizes of each receiving opening 121 and / or each protrusion 221 can be different, so as to adapt to wires with different numbers of metal wires and different sizes. In actual use, the user places it into the corresponding receiving opening 121 according to the number of metal wires in the wire for pressing. As Figure 14 shown in, the five receiving openings 121 are respectively the first receiving opening 1210, the second receiving opening 1211, the third receiving opening 1212, the fourth receiving opening 1213, and the fifth receiving opening 1214, and the five protrusions 221 are respectively the first protrusion 2213, the second protrusion 2214, the third protrusion 2215, the fourth protrusion 2216, and the fifth protrusion 2217; the first receiving opening 1210 and the first protrusion 2213 are applicable to the wire core with 12 metal wires, the second receiving opening 1211 and the second protrusion 2214 are applicable to the wire core with 13 metal wires, the third receiving opening 1212 and the third protrusion 2215 are applicable to the wire core with 14 metal wires, the fourth receiving opening 1213 and the fourth protrusion 2216 are applicable to the wire core with 15 metal wires, and the fifth receiving opening 1214 and the fifth protrusion 2217 are applicable to the wire core with 16 metal wires.

[0077] In an alternative embodiment, the receiving opening 121 may be rectangular. The advantage of this implementation is that the manufacturing and processing of the receiving opening 121 are relatively simple. However, when multiple metal wires are squeezed in the receiving opening 121, their arrangement is relatively irregular. As a result, some metal wires are under greater pressure while others are under less pressure. On the one hand, this is not conducive to the stability of the wire core shaping; on the other hand, due to the irregular arrangement of the metal wires, in some small probability cases, a metal wire happens to be located at the center of the receiving opening 121. When pressed, the pressure caused by the protrusion 221 directly acts on this metal wire and the direction is vertically downward, making it difficult for the metal wire to slide to both sides, and the operator needs to manually adjust the arrangement of the metal wires; on the third hand, the deformation caused by the different pressures on the metal wires will also affect the resistivity of the metal wires, and the uneven force on the metal wires easily leads to uneven resistivity of the metal wires. To solve this problem, this embodiment also provides a preferred embodiment, which specifically includes:

[0078] As Figure 15 shown, the inner wall of the receiving opening 121 is designed as a smooth arc, so that when the preset pliers are held and pressed, the metal wires slide on the inner wall of the receiving opening 121 to a relatively regular arrangement, so that the forces on the metal wires are relatively uniform.

[0079] In an alternative embodiment, when the number of metal wires included in the wire is 13 and the radius of each metal wire is r, the receiving opening 121 is an arc with a radius of and the radian angle of the arc is greater than or equal to 210°. That is, for a wire core with 13 metal wires, the receiving opening 121 can be an arc with a radius of and the radian angle of the arc is greater than or equal to 210°, where r is the radius of the metal wire. Moreover, the top angle 2210 of the protrusion 221 is designed such that when the first jaw 12 and the second jaw 22 are in the closed state, the top angle 2210 does not directly contact the metal wire directly below, but there is a certain gap between it and the metal wire. In an alternative embodiment, for example, the top angle 2210 can be aligned with the center of the receiving opening 121. Also, the top angle 2210 of the protrusion 221 is also a smoothly transitioning arc to avoid damaging the metal wire.

[0080] Taking an example where a wire contains 13 metal wires and the diameter of each metal wire is 0.3 mm, the corresponding receiving opening 121 and protrusion 221 matching this wire can be as Figure 16As shown, the height of the receiving opening is 0.9507 mm, the width of the receiving opening is 1.459 mm, the vertical distance between the apex angle 2210 of the protrusion 221 and the top of the first arc-shaped surface 2211 is 0.3507 mm, the vertical distance between the side edge and the top of the first arc-shaped surface 2211 is 0.1295 mm, and the first arc-shaped surface 2211 and the second arc-shaped surface 2212 are mirror-symmetric with respect to the central vertical line of the receiving opening 121. It should be noted here that the dimension information here refers to the dimensions set by those skilled in the art when designing the preset pliers. In actual use, there may be errors in the production process of the preset pliers. Therefore, the dimension information here does not represent the dimension information of the preset pliers actually used.

[0081] Embodiment 2:

[0082] Based on the method described in Embodiment 1, the present invention combines specific application scenarios and uses technical expressions in relevant scenarios to elaborate on the implementation process in the characteristic scenarios of the present invention.

[0083] Taking the connection of a copper wire and an aluminum wire containing 13 metal wires using an MC4 connector as an example, the method for anti-corrosion connection of dissimilar metals of the connector provided in this embodiment specifically includes:

[0084] (1) Strip the insulating sheath on the outer layer of the position to be connected of the aluminum wire to expose the wire core.

[0085] (2) In order to avoid the increase in contact resistance and the influence on service life caused by the detachment of the tin dipping layer on the surface of the aluminum wire during the crimping process, place the wire core into the receiving opening 121 of the preset pliers shown, and hold and press the first pliers handle 11 and the second pliers handle 21 to shape the wire core in advance. Figure 10 (3) After impregnating the surface of the aluminum wire connection part with a soldering flux, perform hot tin dipping to form a uniform tin layer, and the tin layer thickness > 100 um; among them, the soldering flux is a special soldering flux for aluminum to enhance the adhesion of the tin layer. Compared with the traditional method of electroplating tin on the entire surface of the aluminum wire, here only the connection part is dipped in tin, which greatly reduces the cost, and the hot tin dipping forms a thicker tin protection layer compared with the traditional electroplating tin (<10 um).

[0086] (4) The surface of the MC4 copper core matrix (i.e., the terminal) is electroplated with tin. The commonly used tin-plated MC4 copper cores on the market have a relatively thin tin layer, which may cause the tin layer to fall off during direct crimping, resulting in copper exposure and affecting the service life. To solve this problem, a two-step tin plating method is adopted. In the first step, the entire copper core is placed in the electroplating solution for uniform tin plating. In the second step, the crimping part is retained in the electroplating solution and the other parts are taken out for longer-time tin plating of the crimping part alone to increase the thickness.

[0087] (5)

[0088] (5) After completing steps (1) to (5), use a special MC4 crimping tool to crimp the tinned aluminum joint part to the MC4 tinned copper core (pressure 5 - 200 MPa, holding pressure time 2 s), ensuring that the contact area is ≥ 90%. The crimping part of the MC4 tinned copper core adopts an opening design, and an inverted buckle crimping is performed to ensure the tensile strength after crimping; among them, before crimping, align the notched part of the aluminum wire core with the center position of the opening of the terminal, so that when crimping, the inverted buckle position of the opening corresponds to the notch. In actual use, the crimping point can also be welded by high-frequency induction welding or soldering, and the tin layers are melted together to form a metallurgical bond.

[0089] (6) After the aluminum wire is crimped to the corresponding terminal, the same connection action with the corresponding terminal is also performed on the copper wire, and its specific method is implemented based on the same concept as the aluminum wire and will not be elaborated here.

[0090] (7) Connect the two terminals (i.e., the male terminal and the female terminal), and finally install the MC4 plastic housing on the aluminum wire connected to the MC4 tinned copper core.

[0091] Based on Example 1 and the above method, this embodiment also provides an electrical transmission system, and the wires in the electrical transmission system are connected using the connector dissimilar metal anti-corrosion connection method described in Example 1. The electrical transmission system is used in a photovoltaic system.

Claims

1. A method for anti-corrosion connection of dissimilar metals in connectors, characterized in that: The conductor comprises an insulating sheath and a core, wherein the core comprises a plurality of metal wires; the method comprises: Dipping flux on the surface of the connection portion of the metal wire; Using hot-dip plating to plate a first anti-oxidation layer on the surface of the connection portion of the metal wire, so as to connect the connection portion covered with the first anti-oxidation layer to other wires; The connecting portion of the metal wire is exposed after the insulating coating of the wire at the position to be connected is stripped off.

2. The method for anti-corrosion connection of dissimilar metals in connectors according to claim 1, characterized in that: The method also includes: A protective metal having a first thickness is plated on the surface of the connector terminal to obtain a second anti-oxidation layer.

3. The method for anti-corrosion connection of dissimilar metals of connectors according to claim 2, characterized in that: The method also includes: The crimping portion of the terminal is retained in the electroplating solution to be plated with a second thickness of protective metal, so as to increase the thickness of the second anti-oxidation layer of the crimping portion and provide loss space for the terminal crimping process.

4. The method for anti-corrosion connection of dissimilar metals in connectors according to any one of claims 1 to 3, characterized in that: The crimping pressure used when crimping the metal wire in the conductor and the terminal of the connector is 5 to 200 MPa, and the crimping holding time used is 1 to 3 seconds.

5. The method for anti-corrosion connection of dissimilar metals in connectors according to claim 1, characterized in that: Before plating the first anti-oxidation layer on the surface of the connecting portion of the metal wire, the method further comprises: Using a preset clamp to extrude and shape the wire core to shape the wire core into a preset shape, and maintaining the preset shape for subsequent hot-dip plating operations, so that after the first anti-oxidation layer is plated, the overall shape of the wire core matches the shape of the terminal after crimping; The preset shape is a shape having a notch at the center of the wire core, and the notch is used to provide a reserved space for crimping of the terminal to reduce the loss of the first anti-oxidation layer during the terminal crimping process.

6. The connector dissimilar metal anti-corrosion connection method according to claim 5, characterized in that: The preset pliers comprises a first pliers body (1), a second pliers body (2) and a connecting shaft (3); the first pliers body (1) and the second pliers body (2) are connected via the connecting shaft (3); the first pliers body (1) comprises a first pliers handle (11) and a first pliers mouth (12); the second pliers body (2) comprises a second pliers handle (21) and a second pliers mouth (22); The first pliers mouth (12) is provided with a receiving opening (121) for receiving a wire core; A protrusion (221) is provided on the second pliers mouth (22) at a central position corresponding to the accommodating opening (121), and the protrusion (221) is used to squeeze the metal wire of the wire core toward both sides of the accommodating opening (121) when the first pliers handle (11) and the second pliers handle (21) are gripped and pressed, so that the wire core forms the preset shape.

7. The method for anti-corrosion connection of dissimilar metals in connectors according to claim 6, characterized in that: The protrusion (221) comprises a top corner (2210) facing the bottom of the accommodating opening (121) and a first arc-shaped surface (2211) and a second arc-shaped surface (2212) respectively located on both sides of the top corner (2210); The first arcuate surface (2211) and the second arcuate surface (2212) are both bent in the opposite direction of the receiving opening (121), so that when the first clamp handle (11) and the second clamp handle (21) are squeezed, the metal wires arranged around the top angle (2210) slide along the first arcuate surface (2211) or the second arcuate surface (2212) to the two sides of the receiving opening (121).

8. The method for anti-corrosion connection of dissimilar metals in connectors according to claim 6, characterized in that: When the number of metal wires contained in the conductor is 13 and the radius of each metal wire is r, the receiving opening (121) has a radius of An arc, and the arc angle of the arc is greater than or equal to 210°.

9. The method for anti-corrosion connection of dissimilar metals in connectors according to claim 6, characterized in that: The width of the accommodating opening (121) matches the inner diameter of the wire, and the height of the accommodating opening (121) is smaller than the inner diameter of the wire.

10. An electrical transmission system, characterized in that: The conductors in the electrical transmission system are connected using the connector dissimilar metal anti-corrosion connection method described in any one of claims 1-9.

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