Connection structure and connection method

Abstract

To ensure good electrical conductivity between the aluminum conductor, which is made by twisting together strands of wire / cable, and the connecting member, which is made of copper or a copper alloy. [Solution] A connection structure 10 between an aluminum conductor 21 of an electric wire / cable 2 and a connecting member 3 made of copper or a copper alloy, wherein the aluminum conductor is a twisted conductor formed by twisting together a plurality of strands 211 in a circular cross-section when not connected to the connecting member, the connecting member has a connecting cylinder portion 32 into which the aluminum conductor is inserted, and between the connecting cylinder portion and the aluminum conductor is a serration structure consisting of a plurality of protrusions 42 that bite into the aluminum conductor or a serration structure consisting of a plurality of through holes 41 having protrusions 42 on the inner edge that bite into the aluminum conductor, a compound 5 that destroys the oxide film on the surface of the strands of the aluminum conductor is placed inside the serration structure, and the connecting cylinder portion is crimped from the outside so that the compound penetrates to the strands inside the outermost strand of the aluminum conductor.

Description

Technical Field

[0001] The present invention relates to a connection structure and a connection method.

Background Art

[0002] When connecting the conductor of an electric wire / cable to equipment inside a panel such as a terminal block or a breaker, or when connecting it to another electric wire / cable, connection members such as connection terminals or connection pipes having a connection cylinder part into which the conductor of the electric wire / cable is inserted are used. On the other hand, in recent years, electric wires / cables are not only made of copper or copper alloy conductors (hereinafter referred to as copper conductors) that have been used for many years, but the use of aluminum or aluminum alloy conductors (hereinafter referred to as aluminum conductors) with excellent weight reduction is increasing. In order to meet various applications and requirements for the connection members connected to the conductors of electric wires / cables, connection members in various forms have been developed and are in circulation (for example, see Patent Document 1).

[0003] However, many of the connection members in various forms are formed from copper or copper alloy, and furthermore, many of the conductors of the terminal blocks on the other side or other electric wires / cables to be connected using the connection members are also formed from copper or copper alloy. Also, many of the equipment inside the panel such as terminal blocks or breakers for connecting electric wires / cables using connection members have connection parts formed from copper or copper alloy at the connection points of the connection members. When an aluminum conductor of an electric wire / cable is inserted into the connection cylinder part of such a connection member made of copper or copper alloy and caulked, stress relaxation is likely to occur due to the difference in the thermal expansion coefficients of copper and aluminum, and there is a risk of heat generation or the like due to a decrease in contact pressure.

[0004] For this reason, it has been proposed to provide a concavo-convex structure called serration on the inner peripheral surface of the connection cylinder part of a connection member formed from copper or copper alloy, or to insert a protruding member that is cylindrical and has serration formed on its inner peripheral surface inside the connection cylinder part of a connection member formed from copper or copper alloy to connect an aluminum conductor (for example, see Patent Document 2). The serrations, with their multiple protrusions that bite into the aluminum conductor, can suppress the decrease in contact pressure due to stress relaxation. Furthermore, the protrusions of the serrations biting into the aluminum conductor also have the effect of destroying the oxide film formed on the surface of the aluminum conductor. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2000-182726 [Patent Document 2] Patent No. 5552450 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] Incidentally, the aluminum conductors of electric wires and cables sometimes consist of multiple strands of aluminum twisted together. In this case, the serrations destroy the oxide film formed on the surface of the aluminum conductor by the multiple protrusions biting into it. However, in reality, only the oxide film on the aluminum strands closer to the outer circumference of the aluminum conductor is destroyed, while the oxide film on the inner aluminum strands remains, resulting in insufficient conductivity.

[0007] The present invention aims to improve electrical conductivity between an aluminum conductor, formed by twisting strands of electric wires and cables, and a connecting member made of copper or a copper alloy. [Means for solving the problem]

[0008] To solve the above problems, the present invention provides A connection structure between an aluminum conductor of an electric wire or cable and a connecting member made of copper or a copper alloy, The aluminum conductor is a twisted conductor formed by twisting multiple strands of wire together in a circular cross-section, while not connected to the connecting member. The connecting member has a connecting cylindrical portion into which the aluminum conductor is inserted. Between the connecting cylinder and the front aluminum conductor, a serration structure consisting of multiple protrusions that bite into the aluminum conductor or a serration structure consisting of multiple through holes having protrusions on their inner edges that bite into the aluminum conductor is provided. A compound that destroys the oxide film on the surface of the individual wires of the aluminum conductor is placed inside the serration structure. The connecting cylinder portion is crimped from the outside, and the compound penetrates beyond the outermost strand of the aluminum conductor to the inner strands.

[0009] Furthermore, the present invention is A method for connecting an aluminum conductor of an electric wire or cable to a connecting member made of copper or a copper alloy, The aluminum conductor is a twisted conductor formed by twisting multiple strands of wire together in a circular cross-section, while not connected to the connecting member. The connecting member has a connecting cylindrical portion into which the aluminum conductor is inserted. Between the connecting cylinder and the front aluminum conductor, a serration structure consisting of multiple protrusions that bite into the aluminum conductor or a serration structure consisting of multiple through holes having protrusions on their inner edges that bite into the aluminum conductor is provided. A compound that destroys the oxide film on the surface of the individual wires of the aluminum conductor is placed inside the serration structure. The connecting cylinder portion is crimped from the outside, allowing the compound to penetrate beyond the outermost strand of the aluminum conductor to the inner strands. [Effects of the Invention]

[0010] According to the present invention, it is possible to achieve good electrical conductivity between an aluminum conductor, which is made by twisting together strands of electric wires and cables, and a connecting member made of copper or a copper alloy. [Brief explanation of the drawing]

[0011] [Figure 1] This is an exploded perspective view showing the state before connection of the connection structure of electric wires / cables and connection terminals, which is the first embodiment. [Figure 2]It is a perspective view showing immediately before the connection work of the connection structure. [Figure 3] It is a front view showing immediately before the connection work of the connection structure. [Figure 4] It is a perspective view showing the state after the connection work of the connection structure. [Figure 5] FIG. 5(A) is a cross-sectional view along the penetration direction of the through-hole of the serration member, and FIG. 5(B) shows a cross-sectional view of the serration member and the aluminum conductor after caulking. [Figure 6] It is an explanatory view showing the connection structure as viewed from the axial direction and showing the moving state of the compound. [Figure 7] It is a chart showing the measurement results of the resistance values between the aluminum terminals or connection terminals provided at both ends for Samples 1 to 3. [Figure 8] It is a chart showing the measurement results of the resistance values from the strands of each layer from the first layer to the fourth layer to the aluminum terminals or connection terminals for Samples 1 to 3. [Figure 9] It is a cross-sectional view perpendicular to the axis of another aspect of the serration member. [Figure 10] It is a cross-sectional view perpendicular to the axis showing another example of the connection cylinder portion of the connection terminal. [Figure 11] It is a perspective view showing an example in which the sealing structure of the compound is provided outside the connection terminal. [Figure 12] It is a perspective view showing another example in which the sealing structure of the compound is provided outside the connection terminal. [Figure 13] It is a perspective view of the serration member in which the sealing structure is provided inside the connection terminal. [Embodiments for Carrying Out the Invention]

[0012] [Summary of Embodiments of the Invention] Hereinafter, with reference to the drawings, embodiments of a connection structure between an electric wire / cable and a connection member according to the present invention will be exemplified and described. However, although various technically preferable limitations are imposed on each of the embodiments described below for carrying out the present invention, the scope of the present invention is not limited to the following embodiments and illustrated examples. In the following explanation, the direction of the centerline of the electric wire or cable will be referred to as the "axial direction," the direction of the circumference around the centerline as the "circumferential direction," and the direction perpendicular to the centerline as the "radial direction."

[0013] Figure 1 is an exploded perspective view showing the state of the connection structure 10 between the electric wire / cable 2 and the connection terminal 3 as a connecting component before connection; Figure 2 is a perspective view showing the same configuration immediately before connection work; Figure 3 is a front view showing the same configuration immediately before connection work; and Figure 4 is a perspective view showing the same configuration after connection work.

[0014] As shown in the figure, the connection structure 10 includes an electric wire / cable 2, a connection terminal 3 as a connecting member, a serrated member 4 as an intervening body having a serrated structure, and a compound 5.

[0015] [Electric wires and cables] The electric wire / cable 2 consists of an aluminum conductor 21 covered with a coating layer 22. The aluminum conductor 21 has a structure in which multiple strands 211 made of aluminum or an aluminum alloy are twisted together in a circular cross-section. Each strand 211 is sufficiently thinner than the overall outer diameter of the aluminum conductor 21, and in this embodiment, a strand 211 with a circular cross-section is exemplified. There are no limitations on the cross-sectional shape of the strand 211, but it is preferable that the cross-sectional shape allows multiple strands 211 to be twisted together in a circular shape. For example, the cross-sectional shape of the strand 211 does not have to be a perfect circle, and may be polygonal.

[0016] Furthermore, each strand 211 of the aluminum conductor 21 is arranged, for example, to form layers concentrically from the center. The number of layers is exemplified as three or four layers, but there may be more. For example, the aluminum conductor 21 is constructed by arranging six strands 211 in the second layer around a single strand 211 forming the first layer, and then arranging twelve strands 211 in the third layer on the outside of the second layer. Alternatively, when constructing a four-layer conductor, the aluminum conductor 21 is constructed by arranging eighteen strands 211 in the fourth layer on the outside of the three layers made up of twelve strands 211. Note that the number of strands in each layer is an example and is not limited to these numbers. Alternatively, the number of strands 211 in each layer may be increased while adding more outer layers.

[0017] The coating layer 22 is made of an insulating material (for example, cross-linked polyethylene, ethylene propylene rubber, or polyvinyl chloride). The coating layer 22 covers the entire outer circumference of the aluminum conductor 21 along its entire length. The coating layer 22 may also be composed of two layers: an insulating layer and an outer protective layer. When attaching a connection terminal 3 to the electric wire / cable 2, the coating layer 22 is peeled off at the connection end, leaving the aluminum conductor 21 exposed to a length that allows the connection terminal 3 to be attached.

[0018] [Connection terminals] The connection terminal 3 is made of copper or a copper alloy and is a connecting component for electrically connecting the electric wire / cable 2 to a terminal block or other mounting location. The mounting location referred to here is equipment designed for the installation of copper or copper alloy connection terminals. In other words, the terminal block or other mounting location to which the connection terminal 3 is attached must also be made of copper or a copper alloy. However, this is not mandatory. Instead, the terminal block or other mounting location to which the connection terminal 3 is attached may be made of aluminum or an aluminum alloy. Examples of copper alloys include brass alloys, bronze alloys, phosphor bronze alloys, or various other copper alloys. The connector terminal 3 may be tin-plated on its surface.

[0019] The connection terminal 3 has a connection portion 31 at one end that is attached to the mounting location, and a connection cylinder portion 32 at the other end into which the aluminum conductor 21 of the electric wire / cable 2 is inserted, and these are integrally formed.

[0020] The connected portion 31 has a semi-elliptical, flat plate shape extending in the axial direction away from the connecting cylinder portion 32, and a circular hole is formed in its center for fastening to the connection point by passing a screw through it. The connecting cylinder portion 32 is a cylindrical body with a constant inner and outer diameter. The connecting cylinder portion 32 is crimped from the outside by compression or crimping while the aluminum conductor 21 is inserted, with the serrated member 4 (described later) interposed therebetween, thereby connecting the aluminum conductor 21 of the electric wire / cable 2 to the connecting terminal 3. The connected portion 31 and the connecting cylindrical portion 32 may be formed from a single flat plate. For example, one end may extend in the shape of the connected portion 31, and the other end may be a strip that spreads laterally, and the strip portion may be rolled up to form a cylindrical connecting cylindrical portion 32. In this case, the cylindrical joint may be joined.

[0021] [Serrated material] Figure 5(A) is a cross-sectional view of the through-hole 41 of the serrated member 4 along the direction of penetration, and Figure 5(B) is a cross-sectional view of the serrated member 4 and the aluminum conductor 21 after crimping. The serrated member 4 is a cylindrical body made of copper or a copper alloy that is interposed between the aluminum conductor 21 of the electric wire / cable 2 and the connecting cylindrical portion 32. The examples of copper alloys are the same as those for the connecting terminal 3. The serrated member 4 may also be tin-plated on its surface. The serrated member 4 has a plurality of through holes 41 that penetrate from the outer surface to the inner surface. It is desirable that the sum of the lateral areas (areas of the inner surface) of all the through holes 41 that come into contact with the aluminum wires that enter the through holes 41 by crimping exceeds the cross-sectional area of ​​the aluminum conductor. The sum of the lateral surfaces of all through holes 41 = length of the inner circumference of the through hole 41 × depth of the through hole 41 (thickness of the serration member 4) × total number of through holes 41 In other words, the sum of the lateral surfaces of all the through holes 41 obtained from the above is set to exceed the cross-sectional area of ​​the aluminum conductor. Furthermore, the above formula assumes that the aluminum conductor 21 is perfectly contained within all through-holes 41. Therefore, considering that the aluminum conductor may not be able to completely contain all through-holes 41, the coefficient K (for example, 0.5 ≤ K ≤ 0.8) obtained by multiplying the sum of the lateral surfaces of all the through-holes 41 may be set to exceed the cross-sectional area of ​​the aluminum conductor.

[0022] The serrated member 4 is formed by creating multiple through-holes 41 throughout a single rectangular flat plate by punching and pressing from the front to the back surface, and then rolling it into a cylindrical shape. As shown in Figure 5(A), when a through hole 41 is formed in the rectangular flat plate before processing of the serrated member 4 by punching from top to bottom, an edge-shaped protrusion 42 is formed on the lower surface of the rectangular flat plate, projecting in the punching direction along the inner edge of the through hole 41. Since the punching of the through hole 41 in the rectangular flat plate is performed uniformly in the same direction, multiple protrusions 42 are formed on one side of the rectangular flat plate. The rectangular flat plate is then rolled into a cylindrical shape so that each protrusion 42 faces inward, forming a serrated structure consisting of multiple protrusions 42. This allows the aluminum conductor 21 to be inserted into the connecting cylinder portion 32 via the serrated member 4 and crimped from the outside of the connecting cylinder portion 32, thereby easily forming the edge-shaped protrusion 42 on the aluminum conductor 21. This causes penetration and destroys the oxide film on the surface of the wire, allowing the aluminum conductor 21 to enter the through hole 41 and be firmly held in place, as shown in Figure 5(B).

[0023] [Compound] Compound 5 is applied to the outer circumference of the aluminum conductor 21, which is exposed when the coating layer 22 at the connection end of the electric wire / cable 2 is peeled off, before it is inserted into the connecting cylinder portion 32. Alternatively, Compound 5 may be applied to the inside of the serrated member 4. Compound 5 consists of a paste-like mixture containing metal particles (e.g., zinc particles) and a viscous grease (mineral oil-based grease, silicone grease, other greases in general, or castor oil). This compound 5 contains metal fine particles that break down the oxide film on the surface of each strand 211 of the aluminum conductor 21, thereby suppressing heat generation between the aluminum conductor 21, the serrated member 4, and the connecting cylinder portion 32, and allowing a larger current to flow.

[0024] [Method for connecting aluminum conductors of electric wires and cables to connector terminals] The method of connecting the aluminum conductor 21 of the electric wire / cable 2 to the connection terminal 3 will be explained with reference to Figures 1 to 3. This connection method forms the connection structure 10 between the electric wire / cable 2 and the connection terminal 3.

[0025] As shown in Figure 1, the coating layer 22 at the connection end of the electric wire / cable 2 is removed to expose the aluminum conductor 21, and compound 5 is applied to the outer circumference of the aluminum conductor 21. Then, as shown in Figures 2 and 3, the serrated member 4 is inserted inside the connecting cylinder portion 32, and with the aluminum conductor 21 inserted inside the serrated member 4, the connecting cylinder portion 32 of the connecting terminal 3 is set into the recess of one of the pair of dies D1 and D2, die D2. In this state, a hydraulic mechanism or the like is used to apply pressure and compress the connecting cylinder portion 32 from the outside in the diametrical direction using a pair of dies D1 and D2 to crimp the connecting cylinder portion 32. As a result, as shown in Figure 4, the connecting cylinder portion 32 is compressed and crimped according to the shape of the recesses of the pair of dies D1 and D2, and the connecting terminal 3 and the aluminum conductor 21 of the electric wire / cable 2 are electrically connected.

[0026] When the connecting cylinder portion 32 is crimped by the pair of dies D1 and D2, the applied pressure deforms the cross-sectional shape of each strand 211 of the aluminum conductor 21, and as shown in Figure 5(B), each strand 211 of the outermost layer deforms as the protrusions 42 of the serration member 4 bite into it, and enters the through hole 41. Furthermore, as shown by the arrows in Figure 6, the compound 5 applied to the outer circumference of the aluminum conductor 21 is prevented from moving outward by the connecting cylinder portion 32 and the serration member 4, and penetrates into the gaps between each strand 211 of the aluminum conductor 21 during the compression process. Depending on the pressure applied by the pair of dies D1 and D2 during crimping, the compound 5 penetrates to at least the strands 211 inside the outermost layer of strands 211, and if the pressure is large, it penetrates to the deepest (center) strand 211. As a result, the metal microparticles contained in compound 5 destroy the oxide film on the surface of each strand 211 of the aluminum conductor 21.

[0027] [Examples] Samples 1-3, each representing a connection structure with a terminal and wire / cable, were prepared, and a comparative test of their conductive performance was conducted.

[0028] Sample 1, used as a comparative example, is a connection structure with the following conditions. Connection terminals: Aluminum (aluminum terminals) Serration material: None Compound: Yes

[0029] Sample 2, used as a comparative example, has a connection structure with the following conditions. Connection terminals: Copper Serration material: Yes Compound: None

[0030] Sample 3, as an example, is a connection structure consisting of the following conditions. Connection terminals: Copper Serration material: Yes Compound: Yes

[0031] Furthermore, the electric wire / cable 2 used had an aluminum conductor 21 in which the strands 211 consisted of four layers, from the first to the fourth layer.

[0032] For each of the connection structures in samples 1 to 3, the insulation layer 22 at both ends of the wire / cable 2 was removed, connection terminals were attached to the respective aluminum conductors 21, and the resistance between the two terminals was measured using the four-terminal method. The conductivity of the aluminum wire was calculated from the cross-sectional area of ​​the stranded aluminum wire, and the resistance of the terminals themselves on both sides was excluded. The measurement results are shown in the table in Figure 7. The units of the values ​​in Figure 7 are "mΩ".

[0033] In sample 1, since the aluminum terminal is connected to the aluminum conductor, there is no effect of stress relaxation between dissimilar metals. Furthermore, since compound 5 is supplied to the aluminum conductor 21, the oxide film on the strand 211 can also be destroyed, resulting in ideal conductivity.

[0034] Although sample 2 has a serrated member 4 interposed between the connecting cylinder portion 32 and the aluminum conductor 21, thereby suppressing the effects of stress relaxation, the resistance value from the conductor center of the aluminum conductor 21 of the electric wire / cable 2 to the connecting terminal 3 is a much larger value (8.71 mΩ) than the resistance value of the ideal sample 1 (0.24 mΩ). This suggests that the multiple protrusions 42 of the serrated member 4 only penetrate up to the strands 211 around the fourth layer (outermost layer) of the aluminum conductor 21, and therefore only the oxide film of the outermost strands 211 is destroyed.

[0035] In sample 3, a serrated member 4 is inserted between the connecting cylinder portion 32 and the aluminum conductor 21, and the compound 5 is supplied to the aluminum conductor 21. The serrated member 4 is able to suppress the effects of stress relaxation, and the resistance value from the conductor center of the aluminum conductor 21 of the electric wire / cable 2 to the connection terminal 3 is a low value (0.31 mΩ) which is almost the same as the resistance value of sample 1 (0.24 mΩ). This suggests that compound 5 penetrates to the first layer of wires 211, destroying the oxide film on each layer of wires 211, thereby enabling good conductivity from the first layer of wires 211 to the connection terminal 3.

[0036] Furthermore, for each of the connection structures of samples 1 to 3, the covering layer 22 of the electric wire / cable 2 was removed, and the aluminum conductor 21 was separated into individual strands 211. The resistance value between the strands 211 of the first layer located in the center and the aluminum terminal or connection terminal 3 was measured using the four-terminal method (Figure 8, "First Layer"). Similarly, the resistance between the second layer wire 211 and the aluminum terminal or connector 3 was measured (Figure 8, "Second Layer"). Similarly, the resistance between the third layer wire 211 and the aluminum terminal or connection terminal 3 was measured (Figure 8, "Third Layer"). Similarly, the resistance value between the fourth layer wire 211 and the aluminum terminal or connector terminal 3 was measured (Figure 8, "Fourth Layer"). The measurement results are shown in the table in Figure 8. The units of the values ​​in Figure 8 are "mΩ".

[0037] In sample 1, compound 5 penetrates each of the first to fourth layers of the aluminum conductor 21, resulting in low resistance between layers and achieving ideal conductivity.

[0038] In sample 2, the resistance value from the fourth layer to the connection terminal 3 is low, but the resistance values ​​between each of the inner layers, from the first to the third, are all high. This suggests that the multiple protrusions 42 of the serrated member 4 are only able to destroy the oxide film of the wires 211 around the fourth layer (outermost layer).

[0039] On the other hand, sample 3 shows a lower resistance value from the fourth layer to the connection terminal 3, and furthermore, the resistance values ​​between each of the first to third layers further inside are close to those of sample 1. This suggests that the serration member 4 destroys the oxide film of the individual wires 211 around the fourth layer (outermost layer), and the compound 5 penetrates more deeply, destroying the oxide film of each individual wire 211 in the first to fourth layers.

[0040] [Technical Effects in the First Embodiment] In the above connection structure 10, a serrated member 4 having protrusions 42 as a serrated structure is placed between the connecting cylinder portion 32 and the aluminum conductor 21, and a compound 5 is placed inside the serrated member 4, and the compound 5 is penetrated to the inner strands 211 of the aluminum conductor 21 beyond the outermost strands 211 by crimping from the outside of the connecting cylinder portion 32. Therefore, even if the connection terminal 3 is made of copper or a copper alloy, the through-hole 41 of the serrated member 4 bites into the outer circumference of the aluminum conductor 21, suppressing the decrease in contact pressure due to stress relaxation caused by dissimilar metals, and suppressing heat generation between the serrated member 4 and the aluminum conductor 21, thereby enabling good electrical conductivity. Furthermore, compound 5 can break down the oxide film up to the inner strands 211 of the aluminum conductor 21, improving conductivity between the entire aluminum conductor 21 and the connection terminal 3, thereby suppressing heat generation and allowing more current to flow between the entire aluminum conductor 21 and the connection terminal 3. Furthermore, since the connection terminal 3 is made of copper or a copper alloy, the wires and cables 2 can be properly connected via the connection terminal 3 to existing equipment in a panel, such as existing terminal blocks or circuit breakers, where the connection points are made of copper or a copper alloy.

[0041] In particular, the compound 5 of the connection structure 10 penetrates to the core strands 211 of the aluminum conductor 21, further suppressing heat generation and enabling good electrical conductivity between the entire aluminum conductor 21 and the connection terminal 3.

[0042] Furthermore, the connection structure 10 is configured such that the compound 5 penetrates the inner strands of the aluminum conductor 21 due to the crimping pressure on the connection cylinder portion 32. Therefore, in the process of forming the connection structure 10, it is not necessary to apply the compound 5 to each individual strand 211 of the aluminum conductor 21. By simply placing the compound 5 between the serration member 4 and the aluminum conductor 21, it can penetrate the inside of the conductor 21, thereby simplifying the process of forming the connection structure 10 and reducing the workload.

[0043] Furthermore, since the serration structure is provided on the inner surface of the serration member 4, which is an interposing body inserted between the connecting cylinder portion 32 and the aluminum conductor 21, by interposing the serration member 4, it becomes possible to connect various types of existing copper or copper alloy connecting members to the aluminum conductor 21 of the electric wire / cable 2 in a state of good electrical conductivity.

[0044] Furthermore, the serration structure consists of protrusions 42 formed along the inner edges of multiple through holes 41. Therefore, it is not necessary to form the protrusions and recesses separately, and the processing for forming the serration structure can be simplified. Furthermore, since the serration structure is provided with multiple through holes 41, the aluminum conductor 21 enters each through hole 41, and the adhesion and holding force between the aluminum conductor 21 and the serration structure after crimping can be firmly maintained, making it possible to effectively suppress the decrease in contact force due to stress relaxation.

[0045] [Other aspects of serration structure] In the above embodiment, a configuration consisting of a through hole 41 and a protrusion 42 formed on its inner edge was illustrated as the serration structure, but the embodiment is not limited thereto. For example, Figure 9 is a cross-sectional view perpendicular to the axis of the serrated member 4A. As shown in this figure, multiple protrusions 42A may be formed on the inner surface of the cylindrical serrated member 4A without forming through holes 41. In this configuration as well, the crimping pressure causes the protrusions 42A to bite into the aluminum conductor 21, making it possible to firmly maintain the adhesion and holding force between the aluminum conductor 21 and the serrated structure.

[0046] Furthermore, although the above-described embodiment illustrates a configuration in which the serration structure is formed on the serrated member 4, the invention is not limited thereto. For example, Figure 10 is a cross-sectional view perpendicular to the axis showing another example of the connecting tube portion 32B of the connecting terminal 3B. This connector 3B has the same configuration as the connector 3 described above, except that a serrated protrusion 42B is directly formed on the inner surface of the connector cylinder 32B. In this configuration as well, compound 5 (not shown in Figure 10) is supplied between the connecting cylinder portion 32B and the aluminum conductor 21, and the connecting structure is formed by crimping from the outside of the connecting cylinder portion 32B. Alternatively, multiple through holes may be formed in the connecting cylinder portion 32B, and inwardly convex protrusions may be formed on its inner edge to create a serrated structure.

[0047] Since this connection terminal 3B must have a serrated structure within the connection cylinder portion 32B, existing connection members cannot be used. However, the aluminum conductor 21 of the electric wire / cable 2 can be properly connected to existing terminal blocks, circuit breakers, and other equipment in panels where the connection point is made of copper or a copper alloy, as well as to conductors of other electric wires / cables. Furthermore, when forming multiple through holes in the connecting cylinder portion 32B, it is possible to add a serration structure simply by performing a process to create through holes in the existing connecting member afterward.

[0048] [Compound sealing structure] Furthermore, the connection structure between the aluminum conductor 21 of the electric wire / cable 2 and the connection terminal 3 may be configured such that a sealing structure of compound 5 is provided on the outside or inside of the connection cylinder portion 32.

[0049] Figure 11 is a perspective view showing an example where the sealing structure 6C of compound 5 is provided on the outside of the connection terminal 3. This sealing structure 6C shows a configuration in which the end of the connection tube portion 32 of the connection terminal 3 that is opposite to the insertion side of the aluminum conductor 21 is sealed by wrapping it with tape. With this sealing structure 6C configuration, when the aluminum conductor 21 is inserted into the connecting cylinder portion 32 while supplying the compound 5 and then crimped, the end of the connecting cylinder portion 32, which was previously open, is sealed by the sealing structure 6C. This suppresses leakage of the compound 5 to the outside and allows it to penetrate more effectively toward the center of the aluminum conductor 21. Therefore, further improvements in conductivity can be achieved. In the case where multiple through holes are formed in the connecting cylinder portion 32B and inwardly convex protrusions are formed on its inner edge to create a serrated structure, it is preferable to wrap tape around the entire outer circumference of the connecting cylinder portion 32B.

[0050] Furthermore, the end of the connecting cylinder portion 32 of the connecting terminal 3 that is opposite to the insertion side of the aluminum conductor 21 may be sealed with something else that functions similarly. For example, as shown in Figure 12, a sealing structure 6C may be formed by sealing the end of the connecting cylinder portion 32 with a filler such as putty.

[0051] Alternatively, the sealing structure may be provided on the serrated member located inside the connection terminal 3. For example, as shown in Figure 13, the serrated member 4D may be a cylindrical body made of copper or a copper alloy, having multiple through holes 41 formed on its circumferential surface that penetrate from the outer surface to the inner surface, and having a protrusion (not shown) on the inner surface having the same structure as the aforementioned protrusion 42, with the end opposite to the end into which the aluminum conductor 21 is inserted being closed by a closing portion 43D. In this configuration, the closing portion 43D functions as a sealing structure, suppressing leakage of the compound 5 to the outside during crimping and allowing the compound 5 to penetrate more effectively toward the center of the aluminum conductor 21. Furthermore, the serrated member 4D may also be configured to have a protrusion 42A on its inner circumferential surface that does not involve a through hole 41, as shown in Figure 9.

[0052] [others] The embodiments of the present invention have been described above. However, the present invention is not limited to the embodiments described above. For example, a component integrally formed from a single member in an embodiment may be replaced with a component divided into multiple members that are connected or fixed to each other. Also, a component formed by connecting multiple members may be replaced with a component integrally formed from a single member. Furthermore, details shown in the embodiments can be modified as appropriate without departing from the spirit of the invention.

[0053] For example, in the above embodiment, a connecting terminal that can be connected to a terminal block or the like was given as an example of a connecting member, but the invention is not limited to this, nor is it limited to the object to which the electric wire / cable 2 is electrically connected. Furthermore, the connecting member to which the present invention is applied may not be in the form of a connecting terminal, but may be, for example, a cylindrical connecting tube for connecting one electric wire / cable 2 to another electric wire / cable. Furthermore, the connecting member may have a configuration that includes a portion for inserting and connecting the aluminum conductor 21 of the electric wire / cable 2, and a portion for connecting to other objects (for example, a pin, plug, connector, or jack).

[0054] Furthermore, while the serration structure's protrusions are exemplified as projection-like structures, they are not limited to this; for example, they may also be structures of multiple protrusions (rail-like). In that case, the protrusions may be formed along the axial, circumferential, or helical directions. [Explanation of Symbols]

[0055] 2. Electric wires and cables 3.3B Connection terminals (connecting components) 4,4A,4D Serrated Members 5 Compound 6C sealing structure 10 Connection Structure 21 Aluminum conductor 22 Covering layer 31 Connected part 32,32B Connecting tube section 41 Through hole 42, 42A, 42B protrusions 43D Occlusion 211 strands D1, D2 dice

Claims

1. A connection structure between an aluminum conductor of an electric wire or cable and a connecting member made of copper or a copper alloy, The aluminum conductor is a twisted conductor formed by twisting multiple strands of wire together in a circular cross-section, while not connected to the connecting member. The connecting member has a connecting cylindrical portion into which the aluminum conductor is inserted. Between the connecting cylinder and the aluminum conductor, a serration structure consisting of multiple protrusions that bite into the aluminum conductor or a serration structure consisting of multiple through holes having protrusions on their inner edges that bite into the aluminum conductor is provided. A compound that destroys the oxide film on the surface of the individual wires of the aluminum conductor is placed inside the serration structure. A connection structure characterized in that the connecting cylinder portion is crimped from the outside and the compound penetrates to the inner strands of the aluminum conductor beyond the outermost strand.

2. The connection structure according to claim 1, characterized in that the compound penetrates to the strands in the center of the aluminum conductor.

3. The connection structure according to claim 1, characterized in that the serration structure is provided on the inner surface of an interposing body inserted between the connecting cylinder and the aluminum conductor.

4. The connection structure according to claim 1, characterized in that a sealing structure for the compound is provided on the outside or inside of the connection cylinder portion.

5. The connection structure according to claim 1, characterized in that the compound is permeated into the inner strands of the aluminum conductor by the crimping pressure applied to the connecting cylinder portion.

6. The connection structure according to claim 1, characterized in that the deformed aluminum conductor enters the inside of the through hole of the serration structure due to the crimping pressure on the connecting cylinder portion.

7. A method for connecting an aluminum conductor of an electric wire or cable to a connecting member made of copper or a copper alloy, The aluminum conductor is a twisted conductor formed by twisting multiple strands of wire together in a circular cross-section, while not connected to the connecting member. The connecting member has a connecting cylindrical portion into which the aluminum conductor is inserted. Between the connecting cylinder and the aluminum conductor, a serration structure consisting of multiple protrusions that bite into the aluminum conductor or a serration structure consisting of multiple through holes having protrusions on their inner edges that bite into the aluminum conductor is provided. A compound that destroys the oxide film on the surface of the individual wires of the aluminum conductor is placed inside the serration structure. A connection method characterized by crimping the connecting cylinder portion from the outside to allow the compound to penetrate beyond the outermost strand of the aluminum conductor to the inner strands.

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