Electric wire with terminal, wiring harness, and manufacturing method of electric wire with terminal

Abstract

To provide an electric wire with a terminal that has good crimp workability and can achieve both connection strength and connection resistance.SOLUTION: An electric wire with a terminal 10 has a terminal 1 and a coated conducting wire 11 electrically connected with each other. A crimping part 5 of the terminal 1 is a portion crimped with the coated conducting wire 11, and has a conducting wire crimping part 7 that crimps a conducting wire 13 exposed from a leading end of a coating part 15 of the coated conducting wire 11, and a coating crimping part 9 that crimps the coating part 15 of the coated conducting wire 11. The substantially tubular conducting wire crimping part 7 closed in a circumferential direction is compressed and deformed to be crimped with the conducting wire 13. A leading end (electric wire holding part 7a) and a rear end (conduction part 7b) of the conducting wire crimping part 7 are compressed at substantially the same height. The amount of deformation of the rear end (conduction part 7b) of the conducting wire crimping part 7 is larger than the amount of deformation of the leading end (electric wire holding part 7a) of the conducting wire crimping part 7.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electric wire with a terminal, for example, used in an automobile or the like. [Background technology]

[0002] Typically, automotive wiring harnesses are made by connecting crimp terminals to the conductors of covered conductors, bundling them together, and then wiring them as signal lines in automobiles, etc. A typical covered conductor and crimp terminal are connected by removing the covering from the tip of the covered conductor, crimping the exposed conductor to a conductor crimping portion, and then crimping the covering at the covering crimping portion. The combined connection strength of the conductor crimping portion and the covering crimping portion satisfies the connection strength requirements between the crimp terminal and the covered conductor in an automotive wiring harness.

[0003] However, as the electric wires used become thinner, it becomes difficult to maintain strength using only the conductor that constitutes the electric wire, and therefore electric wires containing tension members are being considered. For example, when using an electric wire made of a conductor with a tensile strength of about 30 N, in order to ensure a tensile strength exceeding 80 N required for electric wires for automobiles, an electric wire containing tension members has been proposed in which the conductor is wound spirally around the outer periphery of a metallic or nonmetallic tension member. Such electric wires are prepared by step-stripping the conductor, exposing the tension member, inserting it into a sleeve, crimping the tension member with a steel clamp, and further integrating it with a curable resin such as an adhesive, and crimping the conductor portion with an aluminum clamp or the like (Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 61-046827 [Patent Document 2] Japanese Patent Application Publication No. 8-237839 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, particularly in the automotive field, the number of ECUs and sensors has increased in response to CASE and other trends, resulting in a significant increase in the number of electric wires used. In this situation, increasing the wire diameter of wire harnesses has become an issue. For this reason, there is a demand for even thinner electric wires for automobiles. For example, the conventional general 0.35 sq (sq: mm 2 There is a demand for thin wires with a diameter of 1 / 4" or less.

[0006] Here, the conductor crimping portion must satisfy both the connection strength between the electric wire and the terminal and the electrical connection resistance between the conductor and the terminal. To satisfy the required specifications for both the connection strength with the electric wire and the electrical connection resistance with the conductor, the compression ratio of the conductor crimping portion must be appropriately set. However, as the diameter of the electric wire becomes smaller, it becomes difficult to satisfy both requirements with the same compression ratio.

[0007] For example, when connecting a large-diameter coated conductor to a crimp terminal using conventional technology, the conductor crimping portion can be crimped at a compression ratio that achieves both connection strength and connection resistance. However, as the diameter of the wire becomes smaller, the range of appropriate crimping conditions for both connection strength and connection resistance becomes narrower. This is because, if you try to ensure connection strength, the conductor will break and the connection resistance will increase, and if you prioritize connection resistance, you will not be able to achieve sufficient connection strength, which can lead to the wire coming loose. Thus, the smaller the wire diameter, the more difficult it becomes to achieve both connection strength and connection resistance.

[0008] The present invention has been made in view of the above problems, and has an object to provide an electric wire with a terminal or the like that has good crimping workability and can achieve both connection strength and connection resistance. [Means for solving the problem]

[0009] In order to achieve the above-mentioned object, a first invention is an electric wire with terminal in which a covered conductor wire and a terminal are electrically connected, the terminal includes a conductor crimping portion to which the conductor wire exposed from the covering portion at the tip of the covered conductor wire is crimped, and a covering crimping portion to which the covering portion of the covered conductor wire is crimped, the conductor crimping portion having a substantially tubular shape that is closed in the circumferential direction is compressed and deformed to be crimped to the conductor wire, and the tip of the conductor crimping portion Wire holding portion provided in and 、 Rear end Conductive portion provided in is compressed to approximately the same height, and in a cross section perpendicular to the axial direction, the internal space of the conductive portion is not a substantially uniform circle, and a part of the side of the conductive portion partially protrudes outward, forming a recess on the inner surface of the conductive portion; The aforementioned Conductive part The inner periphery length of Wire holding part The electric wire with terminal is characterized in that the inner periphery length is longer than that of the electric wire with terminal. A portion of the conducting wire may be recessed into the recess. In a cross section perpendicular to the axial direction, the internal space of the electric wire holding portion may be formed into an approximately uniform circle, the recess may not be formed on the inner surface of the electric wire holding portion, and the electric wire may be crimped approximately uniformly from the entire circumference in the electric wire holding portion.

[0010] The coated conductor may be made up of a plurality of the conductors and at least one strength member.

[0011] In a cross section perpendicular to the longitudinal direction of the covered conductor, the strength member may be located approximately at the center of the covered conductor, and the conductor may be disposed on the outer periphery of the strength member.

[0012] The cross-sectional area of ​​the conductor may be 0.35 sq or less.

[0013] According to the first aspect of the present invention, the amount of deformation of the conductor crimping portion is relatively small at the tip end, making excessive deformation (buckling) less likely to occur. Furthermore, the inner surface is not uneven and the inner circumference is short, allowing the conductor crimping portion to be crimped approximately evenly from the periphery. This allows the conductor to be reliably crimped and achieve high tensile strength. For example, if buckling or the like occurs in the conductor crimping portion, the load will not be applied uniformly from the periphery, causing the conductor to slip in areas with weaker load, which may result in a decrease in the tensile strength of the connection. In response, by appropriately deforming the conductor crimping portion and crimping it from the periphery with an approximately uniform load, such slippage can be suppressed and the tensile strength of the connection can be increased.

[0014] On the other hand, by increasing the deformation amount at the rear end of the conductor crimping portion, the conductor crimping portion can be intentionally deformed significantly, causing buckling or the like. When such buckling occurs, the internal space of the conductor crimping portion does not become a substantially uniform circle, and for example, a gap is formed in which a portion of the side of the internal space partially protrudes outward, increasing the inner perimeter. When the internal perimeter is increased and a gap is formed, part of the conductor enters the gap, increasing the contact area between the conductor and the conductor crimping portion and reducing the connection resistance. Furthermore, when the conductor is compressed, part of the conductor escapes into this gap, which reduces the load on the conductor and makes the conductor more likely to slip. However, excessive crushing of the conductor and thus preventing breakage of the conductor can be suppressed.

[0015] In this way, the front end of the conductor crimping portion functions as a wire holding portion that holds the conductor to increase connection strength, and the rear end of the conductor crimping portion functions as a conductive portion that ensures electrical continuity with the conductor to reduce connection resistance. Because the front and rear ends of the conductor crimping portion are compressed to approximately the same height, a standard mold can be used. This simplifies the crimping process.

[0016] Furthermore, since the coated conductor wire has multiple conductor wires and a tension member, the tension members ensure the tensile strength of the conductor wires. In this case, the wire holding portion holds both the conductor wires and the tension members, ensuring high connection strength. Furthermore, since there is no need to connect the tension members and the conductor wires with separate clamps, as in conventional cases, the number of parts required is reduced and the connection process is easier.

[0017] Furthermore, if the conductor is disposed on the outer periphery of the central tension member in a cross section perpendicular to the longitudinal direction of the covered conductor, the conductor can be crimped reliably. In this case, the conductor may be twisted in the longitudinal direction around the outer periphery of the tension member.

[0018] The present invention is particularly effective when using a small diameter coated conductor having a cross-sectional area of ​​0.35 sq. or less, or even when using a small diameter coated conductor having a cross-sectional area of ​​0.3 sq. or less. The present invention is particularly effective when using a small diameter coated conductor having a cross-sectional area of ​​0.05 sq. or less and obtaining a tensile strength of 50 N or more.

[0019] A second invention is a wire harness characterized in that a plurality of electric wires with terminals, including the electric wire with terminal according to the first invention, are integrated together.

[0020] According to the second invention, it is possible to obtain a wire harness in which a plurality of small diameter electric wires are bundled together.

[0022] No. 3 The invention relates to a method for manufacturing an electric wire with a terminal in which a covered conductor wire and a terminal are electrically connected, the terminal comprising: a conductor crimping portion to which the conductor wire exposed from the covering portion at the tip of the covered conductor wire is crimped; and a covering crimping portion to which the covering portion of the covered conductor wire is crimped, the conductor crimping portion having a small diameter portion with relatively small inner and outer diameters and a large diameter portion with relatively large inner and outer diameters, the small diameter portion being formed on the tip end side of the conductor crimping portion, and the large diameter portion being formed on the rear end side of the conductor crimping portion, and when the conductor wire is inserted into the conductor crimping portion and compressed and crimped with a mold, the large diameter portion is deformed by a larger amount than the small diameter portion. The small diameter portion serves as a wire holding portion, and the large diameter portion serves as a conductive portion. The wire holding portion and the conductive portion are compressed to approximately the same height, and in a cross section perpendicular to the axial direction, the internal space of the conductive portion is not a substantially uniform circle. Parts of the side portions of the conductive portion protrude outward, forming recesses on the inner surface of the conductive portion. The inner peripheral length of the conductive portion is longer than the inner peripheral length of the wire holding portion. The present invention relates to a method for manufacturing an electric wire with a terminal.

[0023] No. of 3 According to the present invention, the electric wire with terminal according to the first aspect of the present invention can be easily obtained without using a special mold. [Effects of the Invention]

[0024] According to the present invention, it is possible to provide an electric wire with a terminal or the like that has good crimping workability and can achieve both connection strength and connection resistance. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1 is a perspective view showing an electric wire 10 with a terminal. [Figure 2] FIG. 2 is a cross-sectional view showing the electric wire 10 with terminal. [Figure 3] 4(a) to 4(d) are cross-sectional views of the conductor crimping portion 7. FIG. [Figure 4] FIG. 2 is a diagram showing the terminal 1 and the coated conductor wire 11 before crimping. [Figure 5] 1A is a diagram showing the tip of the conductor 13, and FIGS. 1B to 1D are diagrams showing the tip of the conductor 13 before terminal processing. [Figure 6] 10A and 10B are diagrams showing other forms of the terminal processing unit 19. [Figure 7] 3 is a perspective view showing a state in which the coated conductor wire 11 is inserted into the crimping portion 5. FIG. [Figure 8] 4(a) and 4(b) are cross-sectional views of the conductor crimping portion 7. FIG. [Figure 9] 10(a) and 10(b) are diagrams showing the crimping process of the crimping unit 5. FIG. [Figure 10] FIG. 2 is a diagram showing a terminal 1a and a coated conductor wire 11 before crimping. [Figure 11] FIG. 2 is a diagram showing a terminal 1b and a coated conductor wire 11 before crimping. [Figure 12] FIG. 2 is a diagram showing a terminal 1c and a coated conductor wire 11 before crimping. DETAILED DESCRIPTION OF THE INVENTION

[0026] (First embodiment) Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view showing an electric wire with terminal 10, and Fig. 2 is a cross-sectional view of the electric wire with terminal 10. The electric wire with terminal 10 is configured by electrically connecting a terminal 1 and a coated conductor wire 11.

[0027] The coated conductor wire 11 is composed of a conductor wire 13 made of, for example, copper, a copper alloy, aluminum, or an aluminum alloy, and a coating 15 that coats the conductor wire 13. That is, the coated conductor wire 11 includes the coating 15 and the conductor wire 13 exposed from its tip.

[0028] The terminal 1 is made of, for example, copper, a copper alloy, aluminum, or an aluminum alloy. A coated conductor wire 11 is connected to the terminal 1. The terminal 1 is configured by connecting a terminal body 3 and a crimping portion 5 via a transition portion 4.

[0029] The terminal body 3 is formed by forming a plate material of a predetermined shape into a cylindrical body with a rectangular cross section. The terminal body 3 has an internal elastic contact piece formed by folding the plate material into the rectangular cylindrical body. A male terminal or the like is inserted into the front end of the terminal body 3 to connect it. In the following explanation, an example is shown in which the terminal body 3 is a female terminal that allows insertion of an insertion tab (not shown) of a male terminal or the like, but the present invention is not particularly limited to the detailed shape of the terminal body 3. For example, instead of the female terminal body 3, an insertion tab of a male terminal may be provided, or a bolt fastening portion like a round terminal may be provided.

[0030] The crimping portion 5 of the terminal 1 is a portion that is crimped to the coated conductor wire 11, and includes a conductor crimping portion 7 that crimps the conductor wire 13 exposed from the tip side of the coating portion 15 of the coated conductor wire 11, and a coating crimping portion 9 that crimps the coating portion 15 of the coated conductor wire 11. That is, the conductor wire 13 exposed when the coating portion 15 is stripped is crimped by the conductor crimping portion 7, and the conductor wire 13 and the terminal 1 are electrically connected. The coating portion 15 of the coated conductor wire 11 is crimped by the coating crimping portion 9 of the terminal 1. In this embodiment, the conductor crimping portion 7 and the coating crimping portion 9 are integrally configured to have a tubular (approximately cylindrical) shape that is closed in the circumferential direction.

[0031] Serrations (not shown) may be provided in the width direction (direction perpendicular to the longitudinal direction) on part of the inner surface of the conductor crimping portion 7. By forming serrations in this manner, the oxide film on the surface of the conductor 13 can be easily destroyed when the conductor 13 is crimped, and the contact area with the conductor 13 can be increased.

[0032] In this embodiment, a wire holding portion 7a that holds the conductor wire 13 is provided on the tip side of the conductor crimping portion 7 (the terminal body 3 side of the conductor crimping portion 7), and a conductive portion 7b that establishes electrical continuity with the conductor wire 13 is provided on the rear end side (the coating crimping portion 9 side) of the conductor crimping portion 7. The wire holding portion 7a provided on the tip side (the terminal body 3 side) of the conductor crimping portion 7 has a relatively stronger holding force for the conductor wire 13 than the conductive portion 7b, and the conductive portion 7b provided on the rear end side (the coating crimping portion 9 side) of the conductor crimping portion 7 is formed to establish electrical continuity with the conductor wire 13.

[0033] 3(a) and 3(b) are cross-sectional views perpendicular to the axial direction of the conductor crimping portion 7, with FIG. 3(a) being a cross-sectional view of the wire holding portion 7a and FIG. 3(b) being a cross-sectional view of the conductive portion 7b. As described above, the circumferentially closed, generally tubular, wire crimping portion 7 is compressed and deformed to be crimped to the conductor 13. The leading end (wire holding portion 7a) and the trailing end (conductive portion 7b) of the wire crimping portion 7 are compressed to approximately the same height. That is, the wire holding portion 7a and the conductive portion 7b have approximately the same outer diameter, and the compressed height A of the wire holding portion 7a and the compressed height B of the conductive portion 7b are approximately the same.

[0034] Here, the compression ratio of the wire holding portion 7a (cross-sectional area of ​​the conductor 13 after compression / cross-sectional area of ​​the conductor 13 before compression) is approximately the same as that of the conductive portion 7b, but the deformation amounts of the wire crimping portion 7 are different. That is, the deformation amount of the rear end portion (conductive portion 7b) of the wire crimping portion 7 is larger than the deformation amount of the front end portion (wire holding portion 7a) of the wire crimping portion 7.

[0035] More specifically, the wire holding portion 7a compresses and crimps the conductor 13 approximately uniformly in the circumferential direction into a substantially circular shape, and no large irregularities are formed on the inner surface in the circumferential direction. Therefore, the conductor 13 is compressed approximately uniformly from the entire circumference. This eliminates any weakly compressed areas, ensuring that the conductor 13 is crimped from the entire circumference and achieves high tensile strength. Note that the "approximately circular" shape may be slightly flattened so that it expands in the direction perpendicular to the compression direction (the left-right direction in the figure). Furthermore, the inner and outer surfaces may have some irregularities in the circumferential direction (smaller irregularities than those of the conductive portion 7b, described below).

[0036] Furthermore, the conductive portion 7b is partially bent (buckled) in the circumferential direction of the conductor crimping portion 7, forming large irregularities in the circumferential direction of the inner surface. That is, in a cross section perpendicular to the axial direction, the inner circumferential length of the conductive portion 7b (the rear end of the conductor crimping portion 7) is longer than the inner circumferential length of the wire holding portion 7a (the front end of the conductor crimping portion 7). For example, the internal space of the conductor crimping portion 7 is not a substantially uniform circle, and a gap is formed such that a portion of the side of the internal space partially protrudes outward. As such, the conductive portion 7b has larger irregularities on the inner surface than the wire holding portion 7a, and therefore the compressive load near this recess is lower than in other areas. This may result in slippage between the conductor 13 and the conductor crimping portion 7, but this is not a problem because the tensile strength of the wire holding portion 7a is ensured.

[0037] On the other hand, because a portion of the conductor 13 enters this recess (gap), the contact area between the conductor 13 and the conductor crimping portion 7 is larger at the conductive portion 7b. In this way, the contact area between the conductor 13 and the conductor crimping portion 7 increases, thereby reducing the connection resistance. Furthermore, because a portion of the conductor can escape into the recess (gap) during compression, excessive crushing of the conductor 13 can be prevented. This prevents breakage of the conductor 13 and ensures reliable continuity.

[0038] In the example shown in Figures 3(a) and 3(b), the conductor 13 is made up of 16 wires, but the number of wires in the conductor 13 is not particularly limited. For example, the number of wires may be seven or any other number. It is desirable that the wires are twisted together.

[0039] Furthermore, the coated conductor wire 11 may be configured such that multiple conductor wires 13 (multiple conductor wires) and a tension member 17 are covered with a covering portion 15. The tension member is a member that receives tension in response to a tensile load. For example, as shown in FIGS. 3(c) and 3(d), in a cross section perpendicular to the longitudinal direction of the coated conductor wire 11, at least one tension member 17 may be located approximately at the center of the coated conductor wire 11, and multiple conductor wires 13 may be arranged on the outer periphery of the tension member 17. In this case, both the conductor wires 13 and the tension member 17 are crimped and held by the wire holding portion 7a and the conductive portion 7b. A conductor wire composed of the tension member 17 and the conductor wire 13 is referred to as a composite conductor 12.

[0040] In this case, each of the conductor wires 13 (element wires) arranged on the outer periphery of the strength member 17 may be conductor wires 13 (element wires) of the same cross-sectional area and shape. Furthermore, the conductor wires 13 may be twisted spirally in the longitudinal direction of the coated conductor wire 11 on the outer periphery of the strength member 17. Furthermore, the strength member 17 may be a single (integral) strength wire, or may be made up of multiple element wires.

[0041] Here, the cross-sectional area of ​​the conductor 13 (total cross-sectional areas of the element wires) or, if a reinforcing member 17 is used, the cross-sectional area of ​​the composite conductor 12 (total cross-sectional areas of the conductor 13 and the reinforcing member 17) is preferably 0.35 sq. or less. In this case, it is desirable that the terminal 1 be capable of crimping a conductor 13 having a cross-sectional area of ​​0.35 sq. or less. Furthermore, the cross-sectional area of ​​the conductor 13 or the composite conductor 12 (total cross-sectional areas of the element wires or total cross-sectional areas of the conductor 13 and the reinforcing member 17) is preferably 0.3 sq. or less. In this case, it is desirable that the terminal 1 be capable of crimping a conductor 13 having a cross-sectional area of ​​0.3 sq. or less. Furthermore, if a composite conductor 12 is used, for example, the total cross-sectional area of ​​the conductor 13 and the reinforcing member 17 may be 0.05 sq. or less. The smaller the cross-sectional area of ​​the conductor 13 (or total cross-sectional area of ​​the conductor 13 and the reinforcing member 17), the greater the effect of this embodiment.

[0042] The reinforcing member 17 may be a metal wire such as a steel wire, or may be made of resin or fiber-reinforced resin. As mentioned above, the reinforcing member 17 may be a single wire or a bundle of multiple fibers such as aramid fiber. By using such a reinforcing member 17, it is possible to ensure a tensile strength of 50 N or more for the conductor at the conductor crimping portion 7, even if the cross-sectional area of ​​the composite conductor 12 is 0.05 sq. or less. For example, the electric wires shown in Table 1 can be used as such a composite conductor.

[0043] [Table 1]

[0044] Next, a method for manufacturing the electric wire with terminal 10 will be described. Fig. 4 is a perspective view showing the terminal 1 and the covered conductor wire 11 before crimping. As described above, the terminal 1 has a terminal body 3 and a crimping portion 5. The crimping portion 5 is configured as a substantially cylindrical body with both ends open, with the conductor crimping portion 7 and the covering crimping portion 9 integrated together. The crimping portion 5 is formed, for example, by rolling a plate member, butting the ends together, and joining them in the longitudinal direction by welding or brazing. In other words, the plate thicknesses of the wire holding portion 7a, the conductive portion 7b, and the covering crimping portion 9 are substantially the same.

[0045] The conductor crimping portion 7, which is generally tubular and closed in the circumferential direction, has a small-diameter portion (corresponding to the wire holding portion 7a) formed at the tip end of the conductor crimping portion 7 and having a relatively small inner and outer diameter, and a large-diameter portion (corresponding to the conductive portion 7b) formed at the rear end of the conductor crimping portion 7 and having a relatively large inner and outer diameter. That is, the outer and inner diameters of the wire holding portion 7a are smaller than the outer and inner diameters of the conductive portion 7b. As shown in the figure, the crimping portion 5 is formed, in order from the rear, with an insulation crimping portion 9, a conductive portion 7b, and a wire holding portion 7a, each of which has approximately the same diameter and a predetermined length in the axial direction. Meanwhile, tapered portions whose diameters gradually decrease toward the tip end are formed between the insulation crimping portion 9 and the wire crimping portion 7 (conductive portion 7b) and between the conductive portion 7b and the wire holding portion 7a.

[0046] The step between the conductive portion 7b and the wire holding portion 7a may be formed around the entire circumference (i.e., the conductive portion 7b and the wire holding portion 7a may be concentric circles in the axial direction), but for example, the lower surface side of the wire crimping portion 7 may be straight in the axial direction, and a step may be formed on the upper surface side due to a change in diameter.

[0047] First, as described above, the coating 15 at the tip of the coated conductor wire 11 is stripped to expose the conductor wire 13 at the tip. Next, as shown in Fig. 5(a), a terminal processing section 19 may be formed at the tip of the conductor wire 13 before insertion into the crimping section 5 of the terminal 1. The terminal processing section 19 is a processing section that integrates the individual wires of the conductor wire 13 to prevent them from coming apart.

[0048] 5(b) is a diagram showing the shape of the tip of the conductor wire 13 before terminal processing. In this embodiment, when viewed from the tip of the coated conductor wire 11, the tension member 17 is located approximately in the center, and the conductor wire 13 is located around it. The conductor wire 13 is made up of multiple wires. Note that this embodiment describes a case where the tension member 17 is located in the center, but the same applies to other coated conductor wires.

[0049] 5(b), at least the tip of the conductor 13 can be compressed from the outer periphery to form the end processing portion 19. By compressing the tip of the conductor 13 from the outer periphery in this manner, the wire is prevented from coming apart, and it is easy to insert the wire into the tubular crimping portion 5.

[0050] 5(c), at least the tip of the conductor 13 may be plated all at once to form the end processing portion 19 with a plating layer 21. By plating the tip of the conductor 13 all at once from the outer periphery in this way, the wire is prevented from coming apart, and insertion into the tubular crimping portion 5 is facilitated.

[0051] Note that, depending on the plating method, high temperatures may be generated when plating is performed en bloc from the outer periphery of the conductor wires 13. If plating is performed en bloc after twisting the conductor wires 13 using such a plating method, the tensile strength of the reinforcing members 17 may be deteriorated by the heat, resulting in a decrease in tensile strength.

[0052] In such cases, as shown in FIG. 5(d), a plating layer 21 may be formed on each conductor and then twisted around the outer periphery of the tension member 17. Alternatively, as shown in FIG. 6, a plating layer 21 may be formed on each conductor and then the tips of multiple conductors may be plated together from the outer periphery. In this case, the type of plating for each conductor may be different from the type of plating for all conductors. While batch plating can prevent conductors from coming apart, bundling conductors and plating them all at once may result in thick or thin areas of plating due to the shape of the conductors, etc. In contrast, applying a primer plating treatment to each conductor in advance can reduce this effect and enable approximately uniform batch plating.

[0053] The terminal processing section 19 is not limited to methods using compression or plating, and may be, for example, soldering or welding the tip of the conductor wire 13 to prevent the wire from coming apart. Also, multiple terminal processing methods, such as compression from the periphery and batch plating, may be used in combination.

[0054] Next, as shown in Figure 7, the conductor 13 with its tip processed in this manner is inserted from the rear end side of the tubular crimping portion 5 of the terminal 1. When the tip of the covered conductor wire 11 is inserted into the crimping portion 5, the exposed portion of the conductor wire 13 is located inside the conductor crimping portion 7, and the covering portion 15 is located inside the covering crimping portion 9. At this time, the tip of the conductor wire 13 may protrude from the tip of the conductor crimping portion 7.

[0055] 8(a) is a cross-sectional view perpendicular to the axial direction at the wire holding portion 7a, and FIG. 8(b) is a cross-sectional view perpendicular to the axial direction at the conductive portion 7b. Note that both cross-sectional views are cross-sectional views of a portion other than the end processing portion 19. As described above, the outer diameter D of the conductive portion 7b is larger than the outer diameter C of the wire holding portion 7a. On the other hand, the outer diameter E of the conductor 13 is substantially the same, so the gap between the outer surface of the conductor 13 and the inner surface of the wire holding portion 7a is relatively small, and the gap between the outer surface of the conductor 13 and the inner surface of the conductive portion 7b is relatively large.

[0056] 9(a) is a cross-sectional view showing an upper blade die 31a, a lower blade die 31b, etc., of a terminal crimping blade for manufacturing a terminal-fitted electric wire 10 before crimping, and FIG. 9(b) is a cross-sectional view showing the crimping portion 5 during crimping. The upper blade die 31a and the lower blade die 31b have a substantially semi-cylindrical cavity extending in the longitudinal direction. The upper blade die 31a includes an insulation crimping blade die 34 that corresponds to the insulation crimping portion 9 and has a diameter slightly smaller than the radius of the insulation crimping portion 9, and a conductor crimping blade die 32 that corresponds to the conductor crimping portion 7 and has a diameter smaller than the insulation crimping blade die 34. That is, the upper blade die 31a and the lower blade die 31b are formed so that both the portions that correspond to the conductor crimping portion 7 and the insulation crimping portion 9 have a substantially circular cross section when the terminal 1 is crimped.

[0057] The conductive portion 7b may be relatively longer than the wire holding portion 7a in order to ensure conductivity between the coated conductor wire 11 and the terminal 1. On the other hand, even if the wire holding portion 7a is short, the strength of the wire 13 or the tensile member 17 and the terminal 1 is sufficiently high as long as they are reliably brought into close contact with each other with an appropriate pressure, so the wire holding portion 7a may be relatively shorter than the conductive portion 7b.

[0058] As shown in FIG. 9(b), when the upper blade die 31a and the lower blade die 31b are engaged and the crimping portion 5 is compressed, the conductor crimping portion 7 is crimped onto the conductor wire 13, and the insulation crimping portion 9 is crimped onto the insulation portion 15. At this time, the wire holding portion 7a and the conductive portion 7b are crimped so that their outer surfaces have substantially the same shape. Here, when the crimping portion 5 is compressed and crimped using a mold, the deformation amount of the large diameter portion is greater than the deformation amount of the small diameter portion. That is, in the terminal 1 before crimping, the conductive portion 7b is larger than the wire holding portion 7a, so that the conductive portion 7b deforms more than the wire holding portion 7a, making partial buckling more likely to occur. That is, the inner surface shape of the conductive portion 7b is more likely to be uneven than the inner surface of the wire holding portion 7a.

[0059] In this way, it is possible to obtain the electric wire with terminal 10 in which the deformation amount of the conductive portion 7b is larger than the deformation amount of the electric wire holding portion 7a and the inner circumferential length of the conductive portion 7b is larger than the inner circumferential length of the electric wire holding portion 7a. Furthermore, it is possible to obtain a wire harness in which a plurality of electric wires with terminals are integrated, including the obtained electric wire with terminal 10.

[0060] As described above, the compression ratio of the wire holding portion 7a and the compression ratio of the conductive portion 7b are approximately equal, and the compression ratio of the coating crimping portion 9 is smaller than the compression ratios of the wire holding portion 7a and the conductive portion 7b. Here, if the cross-sectional area of ​​the coating 15 before the crimping step (the total cross-sectional area inside the outer peripheral surface of the coating crimping portion 9) is A0, and the internal cross-sectional area of ​​the coating crimping portion 9 after being compressed by the upper blade die 31a and the lower blade die 31b is A2, then the compression ratio of the coating crimping portion 9 = A2 / A0 (%).

[0061] Similarly, if the cross-sectional area of ​​the conductor 13 before the crimping process (total cross-sectional area of ​​the conductor 13) is A1 and the cross-sectional area inside the conductor crimping portion 7 (wire holding portion 7a or conductive portion 7b) after being compressed by the upper blade 31a and lower blade 31b (total cross-sectional area of ​​the conductor 13) is A3, the compression ratio of the wire holding portion 7a or conductive portion 7b = A3 / A1 (%). Note that the cross-sectional areas of the wire holding portion 7a and the conductive portion 7b differ slightly due to the unevenness of their inner surfaces, and therefore the compression ratio of the wire holding portion 7a may be slightly smaller than the compression ratio of the conductive portion 7b.

[0062] Since the strength of the reinforcing members 17 is higher and they are less likely to deform than the conductor wires 13, the cross-sectional area of ​​the reinforcing members 17 does not decrease significantly during compression, and deformation (reduction in cross-sectional area) of the conductor wires 13 mainly progresses.

[0063] Furthermore, the movement of the strength member wires during compression causes the external shape of the strength member 17 to become uneven, increasing the contact area between the conductor 13 and the strength member 17 and increasing the frictional force. This makes it easier for tension to be transmitted from the conductor 13 to the strength member 17, and is expected to increase the strength of the conductor 13 when tension is applied.

[0064] Furthermore, since the amount of deformation of the strength members 17 is smaller than that of the conductor wires 13, breakage due to a reduction in cross-sectional area is unlikely to occur. In particular, since the conductor wire crimping portion 7 is tubular, the conductor wires 13 are compressed from the entire circumference, and the conductor wires 13 are positioned between the strength members 17 and the conductor wire crimping portion 7, and the strength members 17 and the conductor wire crimping portion 7 do not come into contact with each other, so the strength members 17 are not damaged.

[0065] As described above, according to this embodiment, the conductor crimping portion 7 has the wire holding portion 7a and the conductive portion 7b, so that the wire holding portion 7a can be crimped in a form suitable for ensuring connection strength, and the conductive portion 7b can be crimped in a form suitable for ensuring conductivity. In other words, the wire holding portion 7a and the conductive portion 7b can be made to undergo different amounts of deformation during crimping, so that each portion can be crimped to have an inner surface shape suitable for its purpose.

[0066] Furthermore, by making the tip end side (terminal body 3 side) of the conductor crimping portion 7 the wire holding portion 7a, it is possible to ensure a stronger connection strength. On the other hand, since the conductive portion 7b is arranged on the rear end side (covering portion 15 side) of the conductor crimping portion 7, even if part of the conductor 13 breaks at the wire holding portion 7a, it is possible to ensure electrical continuity between the covered conductor wire 11 and the terminal 1.

[0067] Furthermore, the wire holding portion 7a and the conductive portion 7b have different outer diameters before crimping. Therefore, by performing the crimping operation using the same mold as used for crimping a normal electric wire with a terminal, the deformation amounts of the wire holding portion 7a and the conductive portion 7b can be appropriately adjusted. This makes the operation easy. Furthermore, the inner diameter of the rear end of the wire crimping portion 7 is large, making it easy to insert the conductor 13.

[0068] The present invention is also applicable to coated conductor wires 11 that include reinforcing members 17, ensuring high connection strength even with small-diameter coated conductor wires 11. For example, even if the cross-sectional area of ​​the conductor wire 13 is 0.05 sq or less, the tensile strength of the conductor wire 13 at the wire holding portion 7a can be made 50 N or more. For example, when a coated conductor wire with a composite conductor cross-sectional area of ​​0.05 sq (conductor material: annealed copper, reinforcing member material: PBO fiber) was actually crimped at a conductor compression rate of 80%, favorable results were obtained, with a tensile strength of 50 N or more and a resistance of 0.75 mΩ or less.

[0069] In this case, since both the tension member 17 and the conductor wire 13 are crimped together by the wire holding portion 7a, there is no need to crimp the tension member 17 and the conductor wire 13 separately, and the crimping operation is easy. In the case of a coated conductor wire 11 including the tension member 17, by arranging the tension member 17 approximately in the center of the cross section and arranging the conductor wire 13 on the outer periphery, the terminal 1 and the conductor wire 13 can be reliably crimped together during crimping, and the terminal 1 and the conductor wire 13 can be brought into contact with each other.

[0070] Furthermore, since the conductor crimping portion 7 is substantially cylindrical, the conductor 13 can be reliably crimped from the entire 360° circumference at the wire holding portion 7a in particular. This makes it possible to prevent local stress (deformation) from occurring in the conductor 13 during crimping.

[0071] Here, when the conductor crimping portion 7 of the covered conductor wire 11, in which the conductor wire 13 is disposed around the tension member 17, is crimped, a compressive stress acts radially inside the conductor crimping portion 7. If this compressive stress is small, the frictional force at the contact surface between the conductor wire 13 and the tension member 17 will be smaller than the frictional force at the contact surface between the terminal 1 and the conductor wire 13. For this reason, when a tensile load is applied to the electric wire with terminal 10, the load will be concentrated on the conductor wire 13, making the conductor wire 13 more likely to break.

[0072] On the other hand, slippage occurs at the contact surface between the conductor 13 and the tension member 17, preventing compressive stress from acting on the tension member 17, which may result in the tension member 17 being pulled out without breaking, and the tensile strength of the tension member 17 not being fully exerted. To prevent this phenomenon and obtain sufficient compressive stress through crimping, the frictional force between the conductor 13 and the tension member 17 may be increased. For example, by providing irregularities on the inner surface of the conductor crimping portion 7, the compressive stress on the tension member 17 can be partially increased, preventing it from being pulled out.

[0073] Furthermore, when the conductor crimping portion 7 is cylindrical and has a brazed portion at the joint as in this embodiment, a brazed portion with low hardness will have a smaller compressive stress on the conductor 13, making it easier to pull out the strength member 17. For this reason, it is desirable to remove the brazed portion or to eliminate the brazed portion and make the hardness of the joint formed at the conductor crimping portion 7 equal to the hardness of the material in the conductor crimping portion 7.

[0074] (Second embodiment) Next, a second embodiment will be described. Fig. 10 is a perspective view of a terminal 1a according to the second embodiment before crimping. In the following description, components that have the same functions as those in the first embodiment are given the same reference numerals as in Figs. 1 to 9, and redundant description will be omitted.

[0075] The crimping portion 5 of terminal 1a is similar to that of terminal 1 in that it is formed, in order from the rear, with an insulation crimping portion 9, a conductive portion 7b, and a wire holding portion 7a, but the shape of the crimping portion 5 is different. In terminal 1a, the conductive portion 7b and the insulation crimping portion 9 have approximately the same outer and inner diameters. That is, the conductive portion 7b and the insulation crimping portion 9 are formed with approximately the same diameter and a predetermined length in the axial direction, and no tapered shape is formed between the insulation crimping portion 9 and the conductive portion 7b, but a tapered portion whose diameter gradually decreases toward the tip is formed between the conductive portion 7b and the wire holding portion 7a.

[0076] Although the boundary between the coating crimping portion 9 and the conductive portion 7b is not clear, the coating crimping portion 9 and the conductive portion 7b can be distinguished from each other if, for example, serrations are formed on the inner surface of the conductive portion 7b to reduce contact resistance with the conductor 13. Furthermore, except for special terminals in which the tip of the crimping portion 5 is sealed and watertightness must be ensured on the inner surface of the coating crimping portion 9, the axial length of the coating crimping portion 9 (large diameter portion) is usually shorter than the axial length of the conductor crimping portion 7 (small diameter portion). However, in terminal 1a, the sum of the lengths of the conductive portion 7b and the coating crimping portion 9 (large diameter portion) may be longer than the length of the wire holding portion 7a (small diameter portion).

[0077] According to the second embodiment, the same effects as those of the first embodiment can be obtained. In this way, by making the outer diameter of the conductive portion 7b larger than that of the wire holding portion 7a, the conductive portion 7b can be largely deformed during crimping, regardless of the diameter of the insulation crimping portion 9. In addition, since the rear end side of the crimping portion 5 has a large diameter, the insertion of the conductor 13 is easy.

[0078] (Third embodiment) Next, a third embodiment will be described. Fig. 11 is a perspective view of a terminal 1b according to the third embodiment before crimping. Terminal 1b has substantially the same configuration as terminal 1, but differs in the shape of the crimping portion 5. Terminal 1b has a slit formed between the wire holding portion 7a, the conductive portion 7b, and the insulation crimping portion 9. In other words, the wire crimping portion 7 and the insulation crimping portion 9 are formed separately. The outer diameter of the conductive portion 7b only needs to be larger than the outer diameter of the wire holding portion 7a, and the outer diameters of the conductive portion 7b and the insulation crimping portion 9 may be the same or different.

[0079] Terminal 1b can also be crimped in the same manner as terminal 1. In this case, it is sufficient to crimp so that the end of cover 15 is positioned in the slit between conductor crimping portion 7 and cover crimping portion 9. In this way, by crimping conductor crimping portion 7 so as to form wire holding portion 7a and conductive portion 7b, the same effect as in the first embodiment can be obtained.

[0080] (Fourth embodiment) Next, a fourth embodiment will be described. Fig. 12 is a perspective view of a terminal 1c according to the fourth embodiment before crimping. The terminal 1c has an open barrel type insulation crimping portion 9 that is generally U-shaped and opens upward. Even in this case, the conductor crimping portion 7 is cylindrical, and the outer diameter of the conductive portion 7b is larger than the outer diameter of the wire holding portion 7a. A slit may be provided between the wire holding portion 7a and the conductive portion 7b.

[0081] According to the fourth embodiment, it is possible to obtain the same effects as those of the first embodiment. Furthermore, since the insulation crimping portion 9 is of an open barrel type, it is easy to place, for example, the conductor 13 in the crimping portion 5. For example, the conductor 13 is placed in the insulation crimping portion 9 from above the terminal 1c, and then, in a positioned state, the conductor 13 is slid into the conductor crimping portion 7, thereby facilitating the operation of inserting the conductor 13 into the conductor crimping portion 7.

[0082] Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical scope of the present invention is not limited to the above-described embodiments. It is clear that those skilled in the art can conceive of various modifications and alterations within the scope of the technical ideas described in the claims, and it is understood that these modifications and alterations also fall within the technical scope of the present invention. [Explanation of symbols]

[0083] 1, 1a, 1b, 1c....Terminals 3...Terminal body 4. Transition section 5... Crimping part 7....Conductor crimping section 7a……Wire holding part 7b……Conducting part 9……Sheathing crimping part 10...Terminal-attached wire 11....Covered conductor 12...Composite conductor 13……Conducting wire 15....Covering part 17……Tensile strength body 19...Terminal processing section 21: Plating layer 31a……Top blade type 31b……Lower blade type 32....Conductor crimping blade type 34……Coated crimp blade type

Claims

1. A terminal-attached electric wire in which a coated conductor wire and a terminal are electrically connected, the terminal includes a conductor crimping portion to which the conductor exposed from the coating portion at the tip of the coated conductor wire is crimped, and a coating crimping portion to which the coating portion of the coated conductor wire is crimped, the conductor crimping portion is substantially tubular and closed in the circumferential direction, and is compressed and deformed to be crimped to the conductor; an electric wire with a terminal, characterized in that the wire holding portion provided at the tip end of the wire crimping portion and the conductive portion provided at the rear end are compressed to approximately the same height, the internal space of the conductive portion is not a substantially uniform circle in a cross section perpendicular to the axial direction, parts of the sides of the conductive portion protrude outward to form recesses on the inner surface of the conductive portion, and the inner peripheral length of the conductive portion is longer than that of the wire holding portion.

2. A terminal-equipped electric wire as described in claim 1, characterized in that a portion of the conductor is inserted into the recess.

3. A terminal-equipped wire as described in claim 1 or claim 2, characterized in that in a cross section perpendicular to the axial direction, the internal space of the wire holding portion is formed into an approximately uniform circle, no recess is formed on the inner surface of the wire holding portion, and the conductor is crimped approximately uniformly from the entire circumference in the wire holding portion.

4. 4. The electric wire with terminal according to claim 1, wherein the coated conductor wire comprises a plurality of the conductor wires and at least one tension member.

5. The electric wire with terminal according to claim 4, characterized in that, in a cross section perpendicular to the longitudinal direction of the covered conductor, the strength member is located approximately at the center of the covered conductor, and the conductor is arranged on the outer periphery of the strength member.

6. The electric wire with terminal according to any one of claims 1 to 5, wherein the cross-sectional area of ​​the conductor is 0.35 mm2 or less.

7. A wire harness comprising a plurality of electric wires with terminals integrated together, the electric wire with terminal being the electric wire according to any one of claims 1 to 6.

8. A method for manufacturing an electric wire with a terminal in which a coated conductor wire and a terminal are electrically connected, the terminal includes a conductor crimping portion to which the conductor exposed from the coating portion at the tip of the coated conductor wire is crimped, and a coating crimping portion to which the coating portion of the coated conductor wire is crimped, the conductor crimping portion has a small diameter portion having a relatively small inner diameter and an outer diameter, and a large diameter portion having a relatively large inner diameter and an outer diameter, the small diameter portion is formed on a front end side of the conductor crimping portion, and the large diameter portion is formed on a rear end side of the conductor crimping portion, When the conductor is inserted into the conductor crimping portion and compressed and crimped by a die, the deformation amount of the large diameter portion is larger than the deformation amount of the small diameter portion, the small diameter portion becomes a wire holding portion, the large diameter portion becomes a conductive portion, and the wire holding portion and the conductive portion are compressed to approximately the same height, a conductive portion having an inner circumferential length greater than that of the wire holding portion; ...

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