JP2014160577A - Crimp terminal and wire harness using crimp terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crimp terminal capable of suppressing an increase in cost and preventing water adhesion to a contact part with a wire and a decrease in crimping force, and a wire harness which uses the crimp terminal.SOLUTION: A wire harness 1 includes a wire 10 and a crimp terminal 20. The wire 10 includes an insulation coating part 12 in which a core wire is coated by an insulator and an exposure core wire 11 which exposes a part of the core wire from a tip of the insulation coating part 12. The crimp terminal 20 includes a crimp part 22 into which the wire 10 can be inserted. The crimp part 22 opens on a rear end part 20B and includes a coated crimping part 24 crimped to the insulation coating part 12 and a core crimping part 23 crimped to the exposure core wire 11. Two salients 28 protruding from a reference inner surface 24a extending linearly in a longitudinal direction X to the inner side in a radial direction Y and separated in the longitudinal direction X via a separation part 27 are formed on an inner surface of the coated crimping part 24. A recess 29 which dents from the reference inner surface 24a to the outer side in the radial direction Y is formed in the separation part 27.

Description

  The present invention relates to a wire harness used for an automobile or the like and a crimp terminal used for the wire harness.

  Conventionally, in the fields of automobiles, OA equipment, home appliances, and the like, wire harnesses in which conductive wires having excellent electric conductivity are used as power lines and signal lines are known. The wire harness includes a crimp terminal that is attached to an electric wire and used for connection to other devices. The electric wire has a covering portion covered with an insulator made of thermoplastic synthetic resin, and an exposed portion of a conductor portion where the core wire is exposed from the tip of the covering portion, and a crimp terminal is crimped to each of the covering portion and the exposed portion. Thus, a conductive wire harness is configured. From the viewpoint of weight reduction, an electric wire using aluminum as a core wire material is attracting attention. As the crimp terminal, copper having excellent electrical characteristics is often used.

  For example, when moisture adheres to a contact portion of different metals such as aluminum and copper, so-called galvanic corrosion may occur due to a difference in standard electrode potential. In particular, since the standard electrode potential difference between aluminum and copper is large, corrosion on the aluminum side, which is electrically base, proceeds. For this reason, the connection state between the core wire and the crimp terminal becomes unstable, and there is a risk that an increase in contact resistance or an increase in electrical resistance due to a decrease in the wire diameter, or a disconnection, leading to malfunction of an electrical component or a malfunction. In addition, in a high-temperature environment, an insulator made of a thermoplastic synthetic resin tends to have a low elastic force, and there is a possibility that the pressure-bonding force between the crimp terminal and the electric wire will decrease as the elastic force decreases.

  Among such wire harnesses in contact with different types of metals, there is one in which a resin material is filled so as to cover a connection portion between an electric wire and a crimp terminal (Patent Document 1). Filling the resin material prevents moisture from adhering to the contact portion between the electric wire and the crimp terminal, and prevents a decrease in the crimp force.

JP 2004-111058 A

  However, since the method of Patent Document 1 requires a separate resin material, there arises a problem that the cost of the entire wire harness increases accordingly.

  The present invention has been made in view of such a problem, and a crimp terminal capable of suppressing an increase in cost and preventing adhesion of moisture to a contact portion with an electric wire and a decrease in a crimp force and the crimping thereof. It aims at providing the wire harness using a terminal.

  In order to achieve the above-mentioned object, the first invention has a coated crimping part which has a longitudinal direction and a radial direction perpendicular to the longitudinal direction and is crimped to an insulating coating part of an electric wire in which a conductive core wire is coated with an insulator. A crimp terminal having a core wire crimping portion to be crimped to an exposed core wire of the electric wire exposed from the tip of the insulating coating portion, wherein the core wire crimping portion and the coating crimping portion can insert the electric wire in a circumferential direction. A sealing part having a water-tight cross-sectional hollow shape, located on the opposite side of the core crimping part from the coated crimping part, and wherein the hollow shaped inner surfaces are water-tightly bonded to each other, and an inner surface of the coated crimping part The crimp terminal further includes a reference inner surface that extends linearly in the longitudinal direction, and a recess that is recessed radially outward from the reference inner surface.

  A plurality of convex portions protruding from the reference inner surface inward in the radial direction and spaced apart in the longitudinal direction via a spacing portion where the concave portion is located may be further provided.

  The said convex part and the said recessed part may be provided cyclically | annularly in the circumferential direction of the said insulation coating part.

  The crimp terminal according to the first aspect of the present invention may further include a separating protrusion that protrudes radially inward from the inner surface of the recess.

  In order to achieve the above-described object, the second invention has an insulation coating portion in which a conductive core wire is coated with an insulator, an electric wire having an exposed core wire exposed from the tip of the insulation coating portion, and a longitudinal direction, A wire harness including a coated crimping portion to be crimped to the insulating coating portion and a crimp terminal having a core wire crimping portion to be crimped to the exposed core wire, wherein the wire is inserted into the core wire crimping portion and the coated crimping portion. The crimp terminal has a hollow cross section that is watertight in the circumferential direction, and the crimp terminal has a hollow cross section that is watertight in the circumferential direction. The core crimping portion is located on the opposite side of the coated crimping portion, the sealing portion in which the hollow inner surfaces are adhered to each other in a watertight manner, and the longitudinal direction constituting the inner surface of the coated crimping portion. Extending up A wire harness characterized by further comprising a reference inner surface and a recess that dents radially outward from the reference inner surface, wherein the core wire is made of an aluminum-based material, and the core wire crimping portion is made of a copper-based material. is there.

  According to the present invention, the core wire crimp portion of the crimp terminal is crimped to the exposed core wire of the electric wire, the coating crimp portion is crimped to the insulating coating portion, and further, by forming a recess that dents radially outward from the reference inner surface, Residual stress of the coated crimping portion can be constrained in the concave portion, and a decrease in the crimping force can be prevented even in a high temperature environment.

  In addition, since a plurality of convex portions are formed on the coated crimping portion via the separation portions, moisture can be prevented from entering from the insulating coating portion side in the longitudinal direction, and moisture can be applied to the contact portion between the electric wire and the crimp terminal. Adhesion can be prevented. Furthermore, since the intrusion of moisture and the decrease in the pressure-bonding force can be prevented only by forming the convex portion and the concave portion, it is not necessary to use a separate resin material or the like, and an increase in cost can be suppressed.

  In addition, by providing the convex portion and the concave portion in a ring shape in the circumferential direction of the insulating coating portion, it is possible to prevent moisture from entering and a decrease in the crimping force in the entire circumferential direction.

  In addition, by forming the separation convex portion in the concave portion, it is possible to more effectively prevent the intrusion of moisture and the decrease in the crimping force.

  ADVANTAGE OF THE INVENTION According to this invention, the wire harness using the crimp terminal and crimp terminal which can aim at reduction of cost and can prevent the adhesion of the water | moisture content to the contact part with an electric wire and the fall of a crimping force is provided. be able to.

The disassembled perspective view which shows the wire harness of 1st Embodiment. The perspective view of a wire harness. III-III sectional view taken on the line of FIG. Explanatory drawing explaining the 1st manufacturing method of a wire harness. Explanatory drawing explaining the 2nd manufacturing method of a wire harness. Sectional drawing which shows the wire harness of 2nd Embodiment.

<First Embodiment>
Referring to FIG. 1, the wire harness 1 has a longitudinal direction X and a radial direction Y orthogonal thereto, and includes an electric wire 10 and a crimp terminal 20. The electric wire 10 includes an insulating coating portion 12 in which a conductive core wire is covered with an insulator, and an exposed core wire 11 in which a part of the core wire is exposed from the tip of the insulating coating portion 12. The core wire is made of an aluminum-based material such as aluminum or an aluminum alloy. More specifically, the core wire is formed by twisting a plurality of aluminum alloy wires or the like.

  The crimp terminal 20 extends in the longitudinal direction X, and is a crimp that allows insertion of a male connector (not shown) located at the front end 20A in the longitudinal direction X and a wire 10 located at the rear end 20B. Part 22. The box portion 21 includes an elastic contact piece 21A that comes into contact with the insertion tab of the male connector.

  The crimping part 22 has a hollow cross-sectional shape (cylindrical shape) in which the electric wire 10 can be inserted from the rear end part 20B and extends in the longitudinal direction X, and opens to the rear end part 20B, and a covering crimping part 24 And a core crimping portion 23 positioned between the box portion 21 and the box portion 21. The inner surface of the cover crimping portion 24 is configured by a reference inner surface 24a (see FIGS. 4 and 5) that extends linearly in the longitudinal direction X. On the inner surface of the cover crimping portion 24, two convex portions 28 that protrude inward in the radial direction Y from the reference inner surface 24 a and are spaced apart in the longitudinal direction X via the spacing portion 27 are formed. The convex portion 28 has an annular shape that is continuous in the circumferential direction. The spacing portion 27 has a predetermined dimension in the longitudinal direction X. The two convex portions 28 are substantially parallel to the circumferential direction. At least the crimp portion 22 of the crimp terminal 20 is made of a copper-based material.

  More specifically, the crimping terminal 20 is formed by punching a copper alloy strip such as brass whose surface is tin-plated into a flattened terminal shape (not shown), and then a box portion 21 and a hollow cylindrical body of a hollow rectangular column. It is formed by bending into a three-dimensional terminal shape composed of the crimp portion 22. Furthermore, between the box part 21 and the crimping | compression-bonding part 22, the sealing part 26 which made the hollow inner surface contact mutually watertight is provided. The sealing part 26 is formed by extending in the radial direction Y, bringing the inner surfaces of the crimping part 22 into contact with each other, and being adhered in a watertight manner. As such a bonding method, for example, laser welding can be used.

  The crimping part 22 is joined in a watertight manner by a joining part 25 extending in the longitudinal direction X. Specifically, the end portions of the copper alloy strips punched into the terminal shape can be butted together so as to have a hollow shape, and the joined portion 25 can be formed by welding such as laser welding. In this embodiment, the joint portion 25 is formed at the position shown in the figure, but is not limited to this, and may be formed at any position around the core wire crimping portion 23 and the covering crimping portion 24. Moreover, although the radial direction Y is illustrated in the vertical direction of the drawing, this is only an example, and any radial direction of the electric wire 10 may be used.

  FIG. 2 shows the crimping terminal 20 with the core wire crimping portion 23 and the covering crimping portion 24 crimped radially inward after inserting the electric wire 10, and FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2. . The electric wire 10 is inserted so that the exposed core wire 11 of the electric wire 10 is located in the core wire crimping portion 23 and the insulating coating portion 12 is located in the covering crimping portion 24. The dimension in the longitudinal direction X of the crimping part 22 is larger than the dimension in the longitudinal direction X of the exposed core wire 11. Therefore, when the electric wire 10 is inserted into the crimping portion 22 so that the exposed core wire 11 contacts the sealing portion 26, the exposed core wire 11 and the insulating coating portion 12 are positioned to face the inner periphery of the crimping portion 22.

  The spacing portion 27 is formed with a recess 29 that is recessed from the reference inner surface 24a to the outside in the radial direction Y. The dimension in the radial direction Y between the inner surfaces of the coated crimping portion 24 is larger at the position where the concave portion 29 is provided than at the position other than the position where the convex portion 28 and the concave portion 29 are provided. That is, as shown in FIG. 3, the dimension L1 is larger than the dimensions L2 and L3. Here, the dimension L <b> 1 is a dimension in the radial direction Y between the inner surfaces of the coated crimping portion 24 at the position where the concave portion 29 is provided. The dimensions L2 and L3 are dimensions in the radial direction Y between the inner surfaces of the coated crimping parts 24 at positions other than the positions where the convex portions 28 and the concave portions 29 are provided. The concave portion 29 has an annular shape that is continuous in the circumferential direction. The concave portion 29 may be formed on the entire longitudinal direction X of the separating portion 27 or may be formed on a part thereof.

  In this embodiment, as shown in FIG. 3, the convex portion 28 has a semicircular cross-sectional shape at a portion protruding inward in the radial direction Y, but is not limited thereto, and is a rectangle, a triangle, a trapezoid, or the like. There may be. The concave portion 29 has a trapezoidal cross-sectional shape at a portion protruding outward in the radial direction Y, but is not limited thereto, and may be a rectangle, a triangle, a semicircle, or the like.

  By crimping the crimping portion 22 with the exposed core wire 11 and the insulation coating portion 12 inserted into the crimping portion 22, the core wire crimping portion 23 is crimped to the exposed core wire 11, and the coating crimping portion 24 is crimped to the insulation coating portion 12. The Further, simultaneously with these pressure bonding, the sealing portion 26 can be deformed so as to be crushed into a substantially flat plate shape. The sealing portion 26 can be made watertight by laser welding in such a crushed state.

  In the insulating coating part 12, a thermoplastic synthetic resin having elasticity can be used as an insulator covering the core wire. By using such a material, the rear end portion 20B can be kept watertight when the covering crimping portion 24 is crimped. Since the rear end side of the crimping part 22 is sealed in a watertight manner by the covering crimping part 24 and the front end part is sealed in a watertight manner by the sealing part 26, it is possible to prevent moisture from entering the crimping part 22.

  In the wire harness 1 as described above, the core wire of the electric wire 10 is made of an aluminum-based material, and the core wire crimping portion 23 of the crimp terminal 20 is made of a copper-based material. To do. In the portion where the different metal contacts, there is a possibility of electrolytic corrosion due to moisture adhering. However, in this embodiment, since the two convex portions 28 are formed on the covering crimping portion 24, the insulating covering portion 12 is substantially uneven. Therefore, the moisture intrusion route can be complicated and the distance of the intrusion route can be increased. Thereby, the penetration | invasion of the water | moisture content to the crimping | compression-bonding part 22 can be prevented, and electrolytic corrosion can be prevented.

  Further, by providing the two convex portions 28, the residual stress generated in the insulating coating portion 12 is partially increased unless the concave portion 29 is provided in the separation portion 27 interposed between the two convex portions 28. . And when a residual stress becomes extremely high, stress may act on the outer side beyond the convex part 28. FIG. However, in this embodiment, this can be prevented by providing the recess 29.

  Moreover, as time passes, the force which presses the insulation coating part 12 tends to move so that it may escape to the insulation coating part 12 by the side of the rear-end part 20B which is not covered with the crimping | compression-bonding part 22. FIG. As a result, the crimping force of the coated crimping part 24 may be reduced. In particular, in a high-temperature environment, the insulating covering portion 12 made of thermoplastic synthetic resin tends to have a low elastic force, and the pressure-bonding force between the covering pressure-bonding portion 24 and the insulating covering portion 12 decreases as the elastic force decreases. there is a possibility. However, in this embodiment, by providing the convex portion 28, escape of the pressing force toward the rear end portion 20B is prevented. Furthermore, even if the pressing force escapes to the rear end portion 20B side, a certain amount of residual stress is constrained in the recess 29, so that the pressing force corresponding to the stress can be compensated. Accordingly, it is possible to prevent a decrease in the crimping force between the coating crimping part 24 and the insulating coating part 12 in the vicinity of the rear end part 20B.

  Here, the manufacturing method of the wire harness 1 is demonstrated. There are two methods for manufacturing the wire harness 1. In the first manufacturing method, the electric wire 10 is inserted into the crimp terminal 20 in which the convex portion 28 and the concave portion 29 are previously formed, and the crimp portion 22 is crimped. In the second manufacturing method, the protruding portion 28 is formed when the electric wire 10 is inserted into the crimping terminal 20 in which only the concave portion 29 is formed in advance and the crimping portion 22 is crimped.

  FIG. 4 is an explanatory diagram for explaining a first manufacturing method of the wire harness 1. In the first manufacturing method, the crimp terminal 20 is manufactured by forming two convex portions 28 and a concave portion 29 in a copper alloy strip, punching them into a desired shape, and then joining them into a cylindrical shape.

  The two convex portions 28 protrude from the reference inner surface 24a inward in the radial direction Y, and are formed by press molding so that the reference inner surface 24a is continuous without being interrupted along the circumferential direction when joined in a cylindrical shape. The In the convex part 28, although the cross-sectional shape in the outer surface of the coating crimping | compression-bonding part 24 is dented, it is not restricted to this, Flat may be sufficient.

  The recess 29 is formed by press molding so as to be recessed from the reference inner surface 24a to the outside in the radial direction Y and to be continuous without interruption along the circumferential direction when the reference inner surface 24a is joined in a cylindrical shape.

  The electric wire 10 is inserted into the crimp terminal 20 in which the convex portion 28 and the concave portion 29 are formed in advance on the reference inner surface 24a, and the crimp portion 22 is crimped by a crimp tool (not shown). In such a 1st manufacturing method, it is not necessary to use a special crimping tool by forming the convex part 28 and the recessed part 29 in the coating | compression-bonding crimping part 24 previously. Moreover, it is not necessary to go through a partial caulking process after caulking with a crimping tool. Furthermore, since the convex portion 28 and the concave portion 29 are provided in a desired position in advance, the positional deviation is less likely to occur as compared with the case where it is formed in a later step.

  FIG. 5 is an explanatory view illustrating a second manufacturing method of the wire harness 1. In the second manufacturing method, the crimp terminal 20 is manufactured by forming only the recess 29 in the copper alloy strip, punching it into a desired shape, and then joining it into a cylindrical shape.

  As in the first manufacturing method, the recessed portion 29 of the crimp terminal 20 is recessed from the reference inner surface 24a to the outside in the radial direction Y as shown in FIG. 5, and the reference inner surface 24a has a circumferential direction when joined in a cylindrical shape. It is formed by press molding so as to be continuous without interruption.

  The crimping tool 40 used in the second manufacturing method includes a first crimping die 41 that becomes an anvil and a second crimping die 42 that becomes a crimper. The inner surface shape of the crimping tool 40 has a shape corresponding to the outer surface shape of the core wire crimping part 23 and the coated crimping part 24 after crimping. In particular, the inner surface of the crimping tool 40 corresponding to the covering crimping portion 24 is provided with two mold convex portions 43 at a predetermined interval in the longitudinal direction X. The mold convex portion 43 projects from the inner surface of the crimping tool 40 toward the covering crimping portion 24, and continues on the inner surface of the crimping tool 40 along the circumferential direction without interruption.

  Using such a crimping tool 40, the core crimping portion 23 and the covering crimping portion 24 are added so that the crimping portion 22 of the crimping terminal 20 into which the electric wire 10 is inserted is sandwiched between the first crimping die 41 and the second crimping die 42. Tighten. According to such a second manufacturing method, it is not necessary to provide the convex portion 28 on the covering crimping portion 24 in advance.

  In any of the first manufacturing method and the second manufacturing method, the protruding portion 28 bites into the insulating coating portion 12 by pressure bonding, so that even if a pulling force is applied in the longitudinal direction X, the electric wire 10 is crimped. It is possible to prevent the terminal 20 from being easily detached. Further, in the separation portion 27, the insulating coating portion 12 is deformed along the shape of the concave portion 29, so that it is possible to reliably restrain the partially increased residual stress.

  According to the first embodiment as described above, by providing the plurality of convex portions 28, the inside of the crimping portion 22 can be reliably kept watertight. In addition, by providing the recessed portion 29 in the separation portion 27, the residual stress of the insulating coating portion 12 can be constrained, and a decrease in the crimping force can be prevented. Moreover, since it is not necessary to use a separate resin material or the like in order to maintain the watertightness of the crimping portion 22 and to prevent a decrease in the crimping force, the cost of the wire harness 1 can be reduced accordingly.

<Second Embodiment>
In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment, and detailed descriptions thereof are omitted. Referring to FIG. 6, the concave portion 29 is further provided with a separation convex portion 30 protruding inward in the radial direction Y from the inner surface thereof.

  The separation convex part 30 is an annular shape that is continuous in the circumferential direction. The spacing convex portion 30 is formed at a substantially center of the concave portion 29 in the longitudinal direction X. In this embodiment, the spacing convex portion 30 has a semicircular cross-sectional shape at the portion protruding inward in the radial direction Y, but is not limited thereto, and may be a rectangle, a triangle, a trapezoid, or the like.

  As with the first embodiment, the method for manufacturing the wire harness 1 in the second embodiment includes two methods. In the first manufacturing method, when the electric wire 10 is inserted into the crimp terminal 20 in which the convex portion 28 and the concave portion 29 are previously formed, and the crimp portion 22 is crimped, the separation convex portion 30 is formed. In the second manufacturing method, when the electric wire 10 is inserted into the crimp terminal 20 in which only the concave portion 29 is formed in advance, and the crimp portion 22 is crimped, the convex portion 28 and the separation convex portion 30 are formed.

  In the second embodiment, in either the first manufacturing method or the second manufacturing method, the crimping tool (not shown) has an inner surface shape corresponding to the separating protrusion 30 that is the outer surface of the separating protrusion 30. The shape depends on the shape. That is, the crimping tool used in the second embodiment includes a mold convex portion at a position in the longitudinal direction X corresponding to the approximate center of the concave portion 29. This mold convex part protrudes from the inner surface of the crimping tool toward the covering crimping part 24 and is continuously formed along the circumferential direction on the inner surface of the crimping tool in the same manner as the mold convex part 43 shown in FIG. Has been.

  According to the second embodiment, as in the first embodiment, by providing the plurality of convex portions 28, the inside of the crimping portion 22 can be reliably kept watertight. In addition, by providing the recessed portion 29 in the separation portion 27, the residual stress of the insulating coating portion 12 can be constrained, and a decrease in the crimping force can be prevented. Moreover, since it is not necessary to use a separate resin material or the like in order to maintain the watertightness of the crimping portion 22 and to prevent a decrease in the crimping force, the cost of the wire harness 1 can be reduced accordingly.

  Further, by forming the separation convex portion 30 in the concave portion 29, the residual stress of the insulating coating portion 12 becomes difficult to move in the longitudinal direction, and the residual stress of the coating crimping portion 24 can be more effectively restrained. It is possible to prevent a decrease in force. Further, the intrusion route of moisture can be complicated and the distance of the intrusion route can be increased.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, the technical scope of this invention is not influenced by embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs.

DESCRIPTION OF SYMBOLS 1 ... Wire harness 10 ... Electric wire 11 ... Exposed core wire 12 ... Insulation coating | cover part 20 ... Crimp terminal 21 ... Box part 22 ... Crimp part 23 ... Core wire crimp part 24 ... Cover crimp part 24a ... Standard inner surface 25 ... Joining part 26 ... Sealing Part 27 ... Separation part 28 ... Convex part 29 ... Concave part 30 ... Separation convex part

Claims (5)

A coated crimping portion that has a longitudinal direction and is crimped to an insulation coating portion of an electric wire coated with an insulator, and a core crimping that is crimped to the exposed core wire exposed from the tip of the insulation coating portion A crimp terminal having a portion,
The core wire crimping portion and the coated crimping portion have a hollow cross-sectional shape that allows the electric wire to be inserted and is watertight in the circumferential direction,
A sealing part located on the opposite side of the core crimping part from the coated crimping part, the hollow inner surfaces being water-tightly bonded to each other;
A reference inner surface extending linearly in the longitudinal direction constituting the inner surface of the coated crimp portion;
A crimp terminal comprising a recess recessed from the reference inner surface to the radially outer side.   2. The crimp terminal according to claim 1, further comprising a plurality of convex portions protruding radially inward from the reference inner surface and spaced apart in the longitudinal direction via a spacing portion where the concave portion is located.   The crimp terminal according to claim 2, wherein the convex portion and the concave portion are provided annularly in a circumferential direction of the insulating coating portion.   The crimp terminal according to any one of claims 1 to 3, further comprising a separation protrusion that protrudes radially inward from an inner surface of the recess. An electric wire having an insulating coating portion in which a conductive core wire is coated with an insulator and an exposed core wire exposed from the tip of the insulating coating portion;
A wire harness including a crimping terminal having a longitudinal direction and having a coated crimping part crimped to the insulating coating part and a core crimping part crimped to the exposed core wire,
The core wire crimping portion and the coated crimping portion have a hollow cross-sectional shape that allows the electric wire to be inserted and is watertight in the circumferential direction,
The crimp terminal has the core crimp part and the sheath crimp part that have a hollow cross-sectional shape in which the electric wire can be inserted and is watertight in the circumferential direction, and is opposite to the sheath crimp part of the core crimp part. And a sealing portion in which the hollow inner surfaces are adhered to each other in a water-tight manner, a reference inner surface that linearly extends in the longitudinal direction constituting the inner surface of the covering crimping portion, and radially outward from the reference inner surface A concave portion that is recessed,
The core wire is made of an aluminum-based material, and the core wire crimping portion is made of a copper-based material.

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