Electric wire with terminal

Abstract

To provide an electric wire with a terminal, capable of achieving a required compression ratio of an electric wire (core wire) with fewer number of crimps.SOLUTION: An electric wire 1A with a terminal includes an electric wire 10 formed by coating a conductive core wire 11 with an insulation coating and a terminal 20 crimped to the electric wire 10. The terminal 20 has a terminal contact part 21 which is formed at one end of the terminal 20 in a longitudinal direction and which comes into contact with a mating terminal, and a crimping part 23 which is formed in a cylindrical shape at the other end in the longitudinal direction and to which the core wire 11 inserted inside is crimped. The crimping part 23 is caulked in a shape of a square tube while the core wire 11 is inserted. A recess 30 extending along the longitudinal direction is formed on the outer periphery of the crimping part 23, and the recess 30 has a plurality of divided recesses 31, 32 where compression ratios of the core wire 11 are different from each other.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electric wire with a terminal. [Background technology]

[0002] For example, terminals used in high-current circuits for electric vehicles require low crimping resistance to reduce heat generation at the crimping part, and the electric wire (core wire) needs to be sufficiently compressed at the crimping part. Closed barrel terminals, which are manufactured by machining the terminal contact part and crimping part, have been proposed as terminals for use in high-current circuits (see Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-21543 A Summary of the Invention [Problem to be solved by the invention]

[0004] Such closed barrel terminals have high rigidity in the crimping portion, and if a required compression ratio of the electric wire is obtained by one crimping, the terminal may crack. Therefore, the terminal described in Patent Document 1 is manufactured by appropriately rotating the terminal and the electric wire and crimping three times to obtain the required compression ratio of the electric wire, which increases the time required for crimping and leads to an increase in the manufacturing cost of the electric wire with terminal.

[0005] The present invention has been made in consideration of the problems inherent in the conventional techniques, and an object of the present invention is to provide an electric wire with a terminal that can obtain a required compression ratio of the electric wire (core wire) with a small number of crimping operations. [Means for solving the problem]

[0006] An electric wire with a terminal according to one embodiment of the present invention comprises an electric wire formed by covering a conductive core wire with an insulating covering, and a terminal crimped to the electric wire, the terminal having a terminal contact portion formed at one longitudinal end of the terminal with which a mating terminal comes into contact, and a crimping portion formed in a tubular shape at the other longitudinal end to which the core wire inserted therein is crimped, the crimping portion being crimped into a square tube shape with the core wire inserted therein, a recess formed on the outer periphery of the crimping portion extending along the longitudinal direction, and the recess having a plurality of divided recesses with different compression rates of the core wire. Effect of the Invention

[0007] According to the present invention, it is possible to provide an electric wire with a terminal that can obtain a required compression ratio of the electric wire (core wire) with a small number of crimping operations. [Brief description of the drawings]

[0008] [Figure 1] 1 is a perspective view showing an example of an electric wire with a terminal according to a first embodiment. [Diagram 2] 1 is a schematic cross-sectional view of a main part of an electric wire with a terminal according to a first embodiment. [Diagram 3] FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. [Figure 4] FIG. 3 is a cross-sectional view taken along line BB in FIG. [Diagram 5] FIG. 2 is a schematic perspective view showing a terminal and an electric wire before crimping. [Figure 6] 3 is a schematic cross-sectional view of a main portion showing a terminal and an electric wire before crimping. FIG. [Figure 7] 4 is a schematic cross-sectional view of the main part showing a terminal and an electric wire in a crimped state. FIG. [Figure 8] FIG. 11 is a perspective view showing an example of an electric wire with a terminal according to a second embodiment. [Figure 9] FIG. 6 is a schematic cross-sectional view of a main part of an electric wire with a terminal according to a second embodiment. [Figure 10] 10 is a cross-sectional view taken along line CC in FIG. 9. [Figure 11] FIG. 10 is a cross-sectional view taken along line DD in FIG. [Figure 12]FIG. 2 is a schematic perspective view showing a terminal and an electric wire before crimping. [Figure 13] 3 is a schematic cross-sectional view of a main portion showing a terminal and an electric wire before crimping. FIG. [Figure 14] 4 is a schematic cross-sectional view of the main part showing a terminal and an electric wire in a crimped state. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, the electric wire with terminal according to the present embodiment will be described in detail with reference to the drawings. Note that the dimensional ratios in the drawings are exaggerated for the convenience of explanation and may differ from the actual ratios.

[0010] [First embodiment] The terminal-fitted electric wire 1A according to this embodiment is used in a large current circuit such as a charging connector for charging the battery of an electric vehicle or the like.

[0011] 1 to 4, an electric wire with terminal 1A according to the first embodiment includes an electric wire 10 and a terminal 20 crimped to the electric wire 10. In the drawings, an arrow X indicates the longitudinal direction (axial direction) of the electric wire with terminal 1A and the terminal 20, and an arrow Y indicates the width direction (left-right direction) perpendicular to the longitudinal direction of the electric wire with terminal 1A and the terminal 20.

[0012] The electric wire 10 has a conductive core wire 11 and an insulating coating (not shown) that covers the core wire 11. The core wire 11 is configured by bundling together a plurality of conductive metal wires formed of a metal material such as copper. At the end of the electric wire 10, the insulating coating is removed to expose the core wire 11, and this exposed core wire 11 is crimped to the terminal 20.

[0013] The terminal 20 of this embodiment is a female terminal. The terminal 20 has a terminal contact portion 21 formed at one end in the axial direction X and connected to a mating member (not shown) of a mating terminal (male terminal) through contact therewith, and a crimping portion 23 formed in a hollow cylindrical shape at the other end in the axial direction X and crimped to the electric wire 10 (core wire 11). This terminal 20 is also called a closed barrel terminal, and is manufactured by cutting out the outer periphery and the inside of a solid metal round bar with a cutting tool such as a cutting tool so that it can withstand a large current capacity. Therefore, the terminal contact portion 21 and the crimping portion 23 are formed integrally.

[0014] Terminal contact portion 21 has a contact portion 22, which is in contact with a mating terminal for electrical connection. Terminal 20 of this embodiment also has an attachment portion 25 formed between terminal contact portion 21 and crimping portion 23, and a sealing member such as a rubber plug is attached to this attachment portion 25.

[0015] The crimping portion 23 has a cylindrical body 24A, which forms a closed end face 24a on the terminal contact portion 21 side in the axial direction X and forms an open end face 24b on the opposite side of the closed end face 24a to the terminal contact portion 21 side in the axial direction X (see FIG. 6). The core wire 11 of the electric wire 10 is inserted into the internal space of the crimping portion 23 (body 24A) through the open end face 24b. Then, with the core wire 11 inserted, an external force is applied to the body 24A to tighten it, thereby deforming the body 24A and crimping the core wire 11 of the electric wire 10 to the terminal 20 (crimping portion 23).

[0016] Therefore, the electric wire 10 (core wire 11) is compressed at a predetermined compression ratio in the crimping portion 23. Incidentally, in this embodiment, the "compression ratio" is calculated by (cross-sectional area after compression) / (cross-sectional area before compression). That is, the compression ratio of the core wire is a value (%) obtained by dividing the cross-sectional area of ​​the core wire in a direction perpendicular to the axial direction X after crimping by compression by the cross-sectional area of ​​the core wire in a direction perpendicular to the axial direction X before crimping by compression. For example, a compression ratio of 70% means that the cross-sectional area of ​​the electric wire 10 (core wire 11) in a direction perpendicular to the axial direction X has been reduced by 30% by compression.

[0017] In this embodiment, the crimping portion 23 is crimped into a hexagonal tube shape with the core wire 11 inserted therein, and a recess 30 extending along the axial direction X is formed on the outer periphery of the crimping portion 23. Also, in this embodiment, a pair of upper and lower recesses 30, 30 facing each other along a direction perpendicular to the axial direction X with the core wire 11 sandwiched therebetween are formed on the outer periphery of the crimping portion 23 (see FIG. 2).

[0018] The recess 30 has a plurality of divided recesses 31, 32 each having a different compression rate for the core wire 11. When a plurality of recesses 30 (divided recesses 31, 32) are provided, it is preferable to provide a step (height difference) between adjacent divided recesses 31, 32. The width of the recess 30 (divided recesses 31, 32) in the left-right direction Y is approximately constant in the axial direction X.

[0019] In this embodiment, among the multiple divided recesses 31, 32, the divided recess 32 having a larger compression ratio value (%) is formed on the terminal contact portion 21 side, and the divided recess 31 having a smaller compression ratio value (%) is formed on the opposite side to the terminal contact portion 21 side. It is preferable that the compression ratio of the core wire 11 in the divided recess 32 on the terminal contact portion 21 side, which has the larger compression ratio value (%), is below 70%, that is, 70% or less. More specifically, it is preferable that the compression ratio of the core wire 11 in the divided recess 32 on the terminal contact portion 21 side, which has the larger compression ratio value (%), is within a range of, for example, 70% to 50%. On the other hand, it is preferable that the compression ratio of the core wire 11 in the divided recess 31 on the opposite side to the terminal contact portion 21 side, which has the smaller compression ratio value (%), is within a range of, for example, 60% to 40%. Furthermore, since the closed barrel terminal (terminal-fitted electric wire 1A) used in a large current circuit has high rigidity of the crimping portion 23, it is preferable that the step (height difference) provided between adjacent divided recesses 31, 32 is not excessively large.

[0020] As shown in FIG. 5, the crimping portion 23 (cylindrical body 24A) is formed in a cylindrical shape before being crimped (crimped) to the electric wire 10 (core wire 11), and the crimping portion 23 (cylindrical body 24A) is crimped into a hexagonal cylindrical shape using a crimping die 50A shown in FIG. 6 and FIG. 7.

[0021] As shown in Fig. 6, the crimping die 50A includes a pair of upper and lower die bodies 51, 51 that are butted against each other, and each die body 51 has a protrusion (indent portion 52). The indent portion 52 has a plurality of divided indent portions 53, 54, and a step (height difference) is provided between adjacent divided indent portions 53, 54. When the pair of die bodies 51, 51 are closed (butted against each other) so as to approach each other in the vertical direction (arrow direction), the indent portion 52 (divided indent portions 53, 54) compresses (presses) the core wire 11 of the electric wire 10 and the crimping portion 23 of the terminal 20, as shown in Fig. 7. As a result, a recess 30 is formed on the outer periphery of the crimping portion 23, which has a plurality of divided recesses 31, 32 with different compression rates for the core wire 11.

[0022] By providing a step (height difference) in the protrusion portion (indent portion 52) of the crimping mold 50A, the number of areas from which the core wire 11 stretches when the electric wire 10 and the terminal 20 are crimped can be increased, thereby increasing the contact path (conductive path) between the terminal 20 and the core wire 11.

[0023] Thus, the electric wire with terminal 1A according to this embodiment includes an electric wire 10 configured by covering a conductive core wire 11 with an insulating covering, and a terminal 20 crimped to the electric wire 10. The terminal 20 has a terminal contact portion 21 formed at one end in the longitudinal direction (axial direction X) of the terminal 20 and contacting a mating terminal, and a crimping portion 23 formed in a cylindrical shape at the other end in the longitudinal direction (axial direction X) and crimped to the core wire 11 inserted therein. The crimping portion 23 is crimped into a rectangular cylindrical shape with the core wire 11 inserted therein. A recess 30 extending along the longitudinal direction (axial direction X) is formed on the outer periphery of the crimping portion 23, and the recess 30 has a plurality of divided recesses 31, 32 having different compression rates for the core wire 11.

[0024] By providing a step (height difference) in the recess 30 on the outer periphery of the crimping portion 23 and changing the compression ratio for each divided recess 31, 32, the elongation of the core wire 11 changes depending on the crimping point, and the contact path (contact area) in the elongation direction (axial direction X) of the core wire 11 can be increased. Since it becomes possible to give a large deformation to the crimping portion 23, it is possible to obtain the required compression ratio of the electric wire 10 (core wire 11) by one crimping. Therefore, it is possible to reduce the number of crimping times to one, and it is possible to suppress manufacturing costs by reducing the time required for crimping. In addition, the contact area is increased not only between the terminal 20 and the electric wire 10 but also between the core wires 11 (plurality of metal strands), so that it is possible to reduce the electrical resistance of the crimping portion 23.

[0025] As described above, according to this embodiment, it is possible to provide the electric wire with terminal 1A that can obtain the required compression ratio of the electric wire 10 (core wire 11) by one crimping operation.

[0026] In the electric wire with terminal 1A, the crimping portion 23 is crimped into a hexagonal tube shape, and a pair of recesses 30, 30 may be formed on the outer periphery of the crimping portion 23, facing each other along a direction perpendicular to the longitudinal direction (axial direction X) with the core wire 11 sandwiched therebetween.

[0027] Since it becomes possible to impart a larger deformation to the crimping portion 23, it is possible to further increase the contact path (contact area) in the elongation direction (axial direction X) of the core wire 11. In addition, a pair of recesses 30, 30 facing each other along a direction perpendicular to the longitudinal direction (axial direction X) with the core wire 11 sandwiched therebetween can be formed on the outer periphery of the crimping portion 23 in one crimping operation (see Figs. 6 and 7), which makes it possible to reduce manufacturing costs by reducing the time required for crimping.

[0028] In the electric wire with terminal 1A, a compression ratio, which is a value obtained by dividing the cross-sectional area of ​​the core wire in a direction perpendicular to the longitudinal direction (axial direction X) after crimping in the divided recesses 31, 32 by the cross-sectional area of ​​the core wire in a direction perpendicular to the longitudinal direction (axial direction X) before crimping, may be 70% or less.

[0029] By forming the recess 30 (divided recesses 31, 32) in this manner, it becomes possible to impart a large deformation to the crimping portion 23 while suppressing breakage of the core wire 11 when the electric wire 10 and the terminal 20 are crimped together.

[0030] [Second embodiment] Next, an electric wire with terminal 1B according to a second embodiment will be described. Note that components that are substantially the same as those in the electric wire with terminal 1A described above are given the same reference numerals, and descriptions thereof will be omitted.

[0031] As shown in Fig. 8 to Fig. 11, in this embodiment, among the multiple divided recesses 31, 32, the divided recesses 32 with the larger compression ratio value (%) are formed on the opposite side to the terminal contact portion 21 side, and the divided recesses 32 with the smaller compression ratio value (%) are formed on the terminal contact portion 21 side. It is preferable that the compression ratio of the core wire 11 in the divided recesses 32 on the opposite side to the terminal contact portion 21 side, which has the larger compression ratio value (%), is below 70%, that is, 70% or less. More specifically, it is preferable that the compression ratio of the core wire 11 in the divided recesses 32 on the opposite side to the terminal contact portion 21 side, which has the larger compression ratio value (%), is within a range of, for example, 70% to 50%. On the other hand, it is preferable that the compression ratio of the core wire 11 in the divided recesses 31 on the terminal contact portion 21 side, which has the smaller compression ratio value (%), is within a range of, for example, 60% to 40%. In addition, since the closed barrel terminal (terminal-fitted electric wire 1B) used in a large current circuit has high rigidity of the crimping portion 23, it is preferable that the step (height difference) provided between adjacent divided recesses 31, 32 is not excessively large.

[0032] As shown in FIG. 12, the crimping portion 23 (cylindrical body 24B) before crimping (before crimping) to the electric wire 10 (core wire 11) is formed in a cylindrical shape, and the crimping portion 23 (cylindrical body 24B) is crimped into a hexagonal cylindrical shape using a crimping mold 50B shown in FIG. 13 and FIG. 14.

[0033] As shown in Fig. 13, the crimping die 50B includes a pair of upper and lower die bodies 51, 51 that are butted against each other, and each die body 51 has a protrusion (indent portion 52). The indent portion 52 has a plurality of divided indent portions 53, 54, and a step (height difference) is provided between adjacent divided indent portions 53, 54. When the pair of die bodies 51, 51 are closed (butted against each other) so as to approach each other in the vertical direction (arrow direction), the indent portion 52 (divided indent portions 53, 54) compresses (presses) the core wire 11 of the electric wire 10 and the crimping portion 23 of the terminal 20, as shown in Fig. 14. As a result, a recess 30 having a plurality of divided recesses 31, 32 with different compression rates for the core wire 11 is formed on the outer periphery of the crimping portion 23.

[0034] According to the electric wire with terminal 1B of this embodiment, like the above-mentioned electric wire with terminal 1A, it is possible to provide an electric wire with terminal 1B that can obtain the required compression ratio of the electric wire 10 (core wire 11) by one crimping.

[0035] Although the present embodiment has been described above, the present embodiment is not limited to this, and various modifications are possible within the scope of the gist of the present embodiment. [Explanation of symbols]

[0036] 1A,1B Terminal Wire 10 Electric wire 11 Core Wire 20 Terminals 21 Terminal contact part 23 Crimping section 30 Recess 31 Split recess 32 Split recess

Claims

1. An electric wire formed by covering a conductive core wire with an insulating coating; a terminal crimped to the electric wire, The terminal is a terminal contact portion formed at one end of the terminal in a longitudinal direction and adapted to come into contact with a mating terminal; a crimping portion formed in a cylindrical shape at the other end in the longitudinal direction and into which the core wire inserted therein is crimped, The crimping portion is crimped into a rectangular tube shape with the core wire inserted therein, A recess extending along the longitudinal direction is formed on the outer periphery of the crimping portion, The recess has a plurality of divided recesses each having a different compression ratio of the core wire. Wire with terminal.

2. 2. The electric wire with terminal according to claim 1, wherein the crimping portion is crimped into a hexagonal tube shape, and a pair of the recesses are formed on an outer periphery of the crimping portion, facing each other along a direction perpendicular to the longitudinal direction with the core wire sandwiched therebetween.

3. 3. The electric wire with terminal according to claim 1, wherein a compression ratio, which is a value obtained by dividing a cross-sectional area of ​​the core wire in a direction perpendicular to the longitudinal direction after crimping in the dividing recess by a cross-sectional area of ​​the core wire in the direction perpendicular to the longitudinal direction before crimping, is 70% or less.

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