Electric wire with terminal, wire harness, and method for manufacturing electric wire with terminal

Abstract

To provide a terminal-equipped electric wire and the like, having excellent crimping workability and also capable of being easily inserted into connectors.SOLUTION: A terminal-equipped electric wire 10 is constituted by a terminal 1 and a coated conductive wire 11 which are electrically connected to each other. A crimp part 5 of the terminal 1 is crimped to the coated conductive wire 11, and has a conductive wire crimp part 7 which is crimped to a conductive wire 13 that is exposed from a coating 15 on a front-end side of the coated conductive wire 11 and a coating crimp part 9 which is crimped to the coating 15 of the coated conductive wire 11. In other words, the conducting wire 13 which is exposed by removing the coating 15 therefrom is crimped by the conductive wire crimp part 7, and the conducting wire 13 and the terminal 1 are electrically connected to each other. The coating 15 of the coated conductive wire 11 is crimped by the coating crimp part 9 of the terminal 1. In the present embodiment, the conductive wire crimp part 7 has a tubular shape (approximately cylindrical shape) to be closed in a peripheral direction, and the coating crimp part 9 has an open barrel shape.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] However, conventional methods for connecting electric wires with tension members require separate crimping processes for crimping the tension members and the conductors, as well as a step-stripping process. This increases the number of parts and the number of man-hours required, resulting in high costs. The step-stripping process itself becomes particularly difficult as the diameter of the electric wire becomes smaller. Thus, conventional methods have the problem of increased processing costs due to the complex and difficult manufacturing process.

[0007] If the conductor crimping portion is tubular, the conductor can be compressed from all sides, preventing local deformation of the conductor. However, as the diameter of the wire becomes smaller, it becomes difficult to insert the wire into the crimping portion of the terminal. In contrast, if the diameter of the conductor crimping portion is made larger, it becomes easier to insert the wire, but the terminal becomes larger, making it difficult to insert the terminal into the connector after crimping.

[0008] The present invention has been made in view of the above problems, and has as its object to provide an electric wire with a terminal that is easy to crimp and insert into a connector. [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 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, At least part of is a circumferentially closed tubularthe coating crimping portion has an open barrel shape, a wire holding portion is provided at the front end of the conductor crimping portion, and a conductive portion is formed at the rear end of the conductor crimping portion for establishing electrical continuity with the conductor, the coated conductor has a plurality of the conductor wires and at least one strength member, the wire holding portion holds both the conductor wires, at least a portion of which is broken, and the strength member, the conductor wires are not broken in the conductive portion, and the electrical resistance of the conductor wires in the conductive portion is lower than the electrical resistance of the conductor wires in the wire holding portion.

[0010] The inner surface of the conductor crimping portion may be provided with projections and recesses. The strength member may also include fibers, and some of the fibers of the strength member may enter the gaps in the broken conductor.

[0011] before It is desirable that the compressibility of the electric wire holding portion be smaller than that of the conductive portion.

[0012] In a cross section perpendicular to the longitudinal direction of the covered conductor wire, the strength member may be located approximately at the center of the covered conductor wire, and the conductive wire may be disposed on the outer periphery of the strength member. Furthermore, the conductive wire may be twisted in the longitudinal direction of the covered conductor wire.

[0013] At least the tip of the conductor may be compressed from the outer periphery, or the conductor may be plated all at once from the outer periphery.

[0014] The cross-sectional area of ​​the conductor is 0.35 mm 2 below Yes and further, the cross-sectional area of ​​the conductive wire may be 0.3 mm 2 below Yes It is also possible.

[0015] According to the first aspect of the present invention, at least a portion of the conductor crimping portion is tubular, so that the conductor can be reliably crimped from the entire circumference. This makes it possible to suppress local stress (deformation) on the conductor during crimping. Meanwhile, because the insulation crimping portion is open barrel type, it is easy to position the conductor when inserting it into the tubular conductor crimping portion. Therefore, even if the diameter of the conductor crimping portion is small, the conductor can be easily inserted into the conductor crimping portion. Furthermore, by including a plurality of the conductor wires and at least one tension member in the coated conductor wire, the tension member can ensure the tensile strength of the conductor wires. In this case, if both the conductor wires and the tension member are held by the wire holding portion, high connection strength can be ensured. Furthermore, since there is no need to connect the tension member and the conductor wire with separate clamps as in the conventional method, the number of parts required is reduced and the connection work is easy. Furthermore, in the wire holding portion, a part of the tensile strength member or the like enters the gap of the broken conductor, thereby increasing the pull-out resistance of the conductor and ensuring connection strength. Meanwhile, electrical continuity between the conductor and the crimp terminal is ensured by the conductive portion.

[0016] Furthermore, by dividing the conductor crimping portion into two functional parts, a wire holding portion that holds the conductor to increase connection strength and a conductive portion that ensures electrical continuity with the conductor to reduce connection resistance, both connection strength and connection resistance can be more reliably satisfied. In this case, the conductor crimping portion can be crimped using the same method as in the past, making the work easier. In addition, in this case, by making the compression ratio of the wire holding portion smaller than that of the conductive portion, i.e., by strongly compressing the wire holding portion, the connection strength between the terminal and the insulated conductor wire can be more reliably ensured.

[0018] 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.

[0019] Furthermore, by forming a terminal processing section such that the tip of the conductor is compressed from the outer periphery or plated all at once from the outer periphery of the conductor, it is possible to prevent the conductor from coming apart when the tip of the conductor is inserted into the tubular conductor crimping section.

[0020] In addition, the cross-sectional area of ​​the conductor is 0.35 mm 2 Insulated conductors with a small diameter of 0.3 mm or less, and conductors with a cross-sectional area of ​​0.3 mm or less mm 2 The present invention is particularly effective when using the following small diameter coated conductor wires.

[0021] 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.

[0022] 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.

[0023] The third invention is a method for manufacturing an electric wire with terminal according to the first invention, characterized in that the cross-sectional area inside the covering portion is 40% or more of the cross-sectional area of ​​the insertion portion of the conductor crimping portion before crimping.

[0024] When removing the coating from the tip of the coated conductor, the conductor may be inserted into the conductor crimping section with a portion of the coating remaining on the tip, and the coating may be removed from the conductor before crimping.

[0025] According to the third aspect of the present invention, the electric wire with terminal according to the first aspect of the present invention can be easily obtained.

[0026] At this time, by inserting the conductor into the conductor crimping portion with part of the coating remaining at the tip of the conductor, it is possible to prevent the conductor from coming apart and to easily insert the conductor into the conductor crimping portion. [Effects of the Invention]

[0027] According to the present invention, it is possible to provide an electric wire with a terminal that has good crimping workability and can be easily inserted into a connector. [Brief explanation of the drawings]

[0028] [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] 10(a) to 10(c) are cross-sectional views of the electric wire holding portion 7a. [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, FIG. 1B is a diagram showing the tip of the conductor 13 before terminal processing, and FIG. 1C and FIG. 1D are diagrams showing the form of the terminal processing portion 19. FIG. [Figure 6] 10(a) and 10(b) are diagrams showing other forms of the terminal processing unit 19. FIG. [Figure 7] 10(a) to 10(c) are diagrams showing the process of inserting the conductor wire 13 into the conductor wire crimping portion 7. FIG. [Figure 8] 10(a) and 10(b) are diagrams showing the crimping process of the crimping portion 5. FIG. [Figure 9] FIG. 2 is a diagram showing a terminal 1a and a coated conductor wire 11 before crimping. [Figure 10] FIG. 2 is a diagram showing a terminal 1b and a coated conductor wire 11 before crimping. [Figure 11] FIG. 2 is a plan view showing the terminal-fitted electric wire 10a. [Figure 12] 10(a) and 10(b) are cross-sectional views of another coated conductor wire 11. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0029] (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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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 coating 15 at the tip side of the coated conductor wire 11, and a coating crimping portion 9 that crimps the coating 15 of the coated conductor wire 11. That is, the conductor wire 13 exposed when the coating 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 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 has a tubular shape (approximately cylindrical) that is closed in the circumferential direction, and the coating crimping portion 9 has an open barrel shape.

[0034] 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.

[0035] The wire crimping portion 7 has a wire holding portion 7a at the tip end (terminal body 3 side) that has a relatively strong holding force for holding the wire 13. Also, a conductive portion 7b is formed at the rear end (covering crimping portion 9 side) of the wire crimping portion 7 to establish electrical continuity with the wire 13. That is, the wire crimping portion 7 has the wire holding portion 7a and the conductive portion 7b.

[0036] The tensile strength (connection strength) of the conductor 13 in the wire holding portion 7a is greater than the tensile strength (connection strength) of the conductor 13 in the conductive portion 7b. For example, the compression ratio (cross-sectional area of ​​the conductor 13 after compression / cross-sectional area of ​​the conductor 13 before compression) in the wire holding portion 7a is smaller than the compression ratio in the conductive portion 7b. In other words, the compression amount in the wire holding portion 7a is greater than the compression amount in the conductive portion 7b, and the wire holding portion 7a is strongly crimped.

[0037] In this way, since the electric wire holding portion 7a is strongly crimped, it is acceptable for at least a portion of the conductor 13 to be broken. When a portion of the conductor 13 breaks, the electrical resistance increases, but by having some of the fibers of the tensile member 17 enter the gaps in the broken conductor 13, the pull-out resistance of the conductor 13 is increased and the connection strength can be ensured. On the other hand, in the conductive portion 7b, the conductor 13 is not broken in order to keep the electrical resistance low.

[0038] The compression rate of the coating crimping portion 9 (cross-sectional area of ​​the coating 15 after compression / cross-sectional area of ​​the coating 15 before compression) may be smaller than the compression rate of the conductive portion 7b. That is, the compression amount of the coating crimping portion 9 may be larger than the compression amount of the conductive portion 7b. Even in this case, the outer diameter of the coating crimping portion 9 is larger than the outer diameter of the conductive portion 7b due to the thickness of the coating 15. The conductor crimping portion 7 may be crimped at a constant compression rate without being divided into the wire holding portion 7a and the conductive portion 7b.

[0039] Fig. 3(a) is a diagram showing a cross section of the electric wire holding portion 7a. In the example shown in Fig. 3(a), the conductor wire 13 is made up of seven wires. In the electric wire holding portion 7a, the conductor wire 13 is compressed and crimped into a substantially circular shape. Note that the shape of the electric wire holding portion 7a after crimping does not necessarily have to be substantially circular, but it is desirable that the cross section shape of the conductive portion 7b after crimping is substantially circular.

[0040] There is no particular limitation on the number of wires in the conductor 13. For example, as shown in Fig. 3(b), the number of wires may be 16. It is preferable that the wires are twisted together.

[0041] Furthermore, the coated conductor wire 11 may have at least one conductor wire 13 and a tension member coated with a coating portion 15. The tension member is a member that receives tension when a tensile load is applied. For example, as shown in FIG. 3(c), 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 around the tension member 17. In this case, each of the conductor wires 13 (strands) arranged around the tension member 17 may have the same cross-sectional area and shape. Furthermore, the conductor wire 13 may be twisted spirally around the tension member 17 in the longitudinal direction of the coated conductor wire 11. In this case, both the conductor wire 13 and the tension member 17 are crimped and held by the wire holding portion 7a and the conductive portion 7b.

[0042] The arrangement of the strength members 17 is not limited to the example shown in FIG. 3(c). For example, the conductor wires 13 and the strength members 17 may be arranged so as to be twisted together. Also, multiple conductor wires 13, each having a strength member 17 coated with a conductor, may be twisted together. Also, the conductor may be arranged so as to cover the outer periphery of the central strength member 17. In other words, in the case of a coated conductor wire 11 containing a strength member, there are no particular limitations on its cross-sectional shape as long as it has at least one conductor wire and at least one strength member. The strength member 17 may be a single (integral) strength wire, or may be made up of multiple strands.

[0043] Here, the cross-sectional area of ​​the conductor 13 (total cross-sectional area of ​​the wires) is preferably 0.35 sq or less, and in this case, it is preferable 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 (total cross-sectional area of ​​the wires) is preferably 0.3 sq or less, and in this case, it is preferable that the terminal 1 be capable of crimping a conductor 13 having a cross-sectional area of ​​0.3 sq or less. Furthermore, for example, when the conductor 13 is used together with a tensile strength member 17, the cross-sectional area of ​​the conductor 13 may be 0.05 sq or less. The smaller the cross-sectional area of ​​the conductor 13, the greater the effect of this embodiment.

[0044] The tension members 17 may be metal wires such as steel wires, or may be made of resin or fiber-reinforced resin. As mentioned above, the tension members 17 may be solid wires or bundles of multiple fibers such as aramid fibers. By using such tension members 17, it is possible to ensure that the tensile strength of the conductor 13 in the wire holding portion 7a is 50 N or more, even if the cross-sectional area of ​​the conductor 13 is 0.05 sq or less.

[0045] 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 the terminal body 3 and the crimping portion 5. The conductor crimping portion 7 is tubular and closed in the circumferential direction, and the cover crimping portion 9 is an open barrel type that opens upward. The conductor crimping portion 7 may be formed, for example, by rolling a plate member, butting the ends together, and joining them in the longitudinal direction by welding or brazing, or the terminal 1 may be formed by expanding a tubular member.

[0046] 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.

[0047] 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.

[0048] In such a case, as shown in Fig. 5(c), 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 conductor 13 into the tubular crimping portion 5.

[0049] 5(d), 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.

[0050] 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 such a plating method is used to perform en bloc plating after twisting the conductor wires 13, the tensile strength of the reinforcing members 17 may be deteriorated by the heat, resulting in a decrease in tensile strength.

[0051] In such cases, as shown in FIG. 6(a), 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(b), 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 performed on the entire conductor. While plating the entire conductors together can prevent them from coming apart, plating the entire conductors together may result in thick or thin areas of plating due to factors such as the shape of the conductors. However, by performing a primer plating process on each conductor in advance, this effect can be reduced, enabling approximately uniform plating to be achieved.

[0052] The method of terminal treatment 19 is not limited to compression or plating, and for example, the tip of conductor 13 may be soldered or welded to prevent the wires from coming apart. Alternatively, multiple terminal treatments, such as compression from the periphery and collective plating, may be used in combination. In the following description, illustration of terminal treatment 19 is omitted.

[0053] Furthermore, when removing the coating 15 from the tip of the coated conductor wire 11, a portion of the coating 15 may be left without being completely removed. FIG. 7(a) is a diagram showing a state in which a portion of the coating 15, that is, a coating 15a, is left at the tip of the conductor wire 13. The coated conductor wire 11 with the coating 15a left at the tip or with the end processing portion 19 formed is placed in the crimping portion 5. In this case, because the coating crimping portion 9 is an open barrel type, the conductor wire 13 of the coated conductor wire 11 can be placed from above the coating crimping portion 9. By placing the conductor wire 13 in the coating crimping portion 9, the positioning of the conductor wire 13 (positioning the coated conductor wire 11 relative to the width direction of the terminal 1) is possible.

[0054] From this state, as shown in Fig. 7(b), by sliding the covered conductor wire 11 toward the conductor crimping portion 7 of the terminal 1, the conductor wire 13 can be easily inserted into the tubular conductor crimping portion 7. In this way, since the conductor wire 13 can be positioned relative to the conductor crimping portion 7, the conductor wire 13 can be easily inserted into the conductor crimping portion 7 even if the inner diameter of the conductor crimping portion 7 before crimping is small (close to the outer diameter of the conductor 13). For example, even if the internal cross-sectional area of ​​the cover 15 (A1 in Fig. 7(a)) is 40% or more of the cross-sectional area of ​​the insertion portion of the conductor crimping portion 7 before crimping (A5 in Fig. 7(a)), the conductor wire 13 can be easily inserted into the conductor crimping portion 7. Furthermore, by forming the aforementioned end processing portion 19 or leaving the covering portion 15a, the conductor 13 can be easily inserted into the conductor crimping portion 7 even if the internal cross-sectional area of ​​the covering portion 15 (A1 in FIG. 7(a)) is 70% or more of the cross-sectional area of ​​the insertion portion of the conductor crimping portion 7 before crimping (A5 in FIG. 7(a)). In this way, the terminal 1 can be made smaller.

[0055] If the conductor 13 is inserted into the conductor crimping portion 7 with part of the coating 15 (coating 15a) remaining at its tip, the coating 15a at the tip of the conductor 13 is removed before crimping, as shown in FIG. 7(c). This allows the coated conductor wire 11 to be positioned in an appropriate position in the crimping portion 5. When the tip of the coated conductor wire 11 is inserted into the crimping portion 5, the exposed portion of the conductor 13 is located inside the conductor crimping portion 7, and the coating 15 is located inside the coating crimping portion 9. At this time, the tip of the conductor 13 may protrude from the tip of the conductor crimping portion 7.

[0056] Next, the terminal 1 with the covered conductor wire 11 placed in the crimping portion 5 is set in the blade dies. FIG. 8(a) is a cross-sectional view showing the upper blade dies 31a and lower blade dies 31b before crimping of the terminal crimping blade dies for manufacturing the terminal-fitted electric wire 10, and FIG. 8(b) is a cross-sectional view showing the crimping portion 5 during crimping. The upper blade dies 31a and lower blade dies 31b have approximately semi-cylindrical cavities extending in the longitudinal direction. The upper blade dies 31a include an insulation crimping blade dies 34 shaped to correspond to the open barrel shape corresponding to the insulation crimping portion 9, and conductor crimping blade dies 32a and 32b corresponding to the tubular conductor crimping portion 7. The upper blade dies 31a and lower blade dies 31b are formed so that the portion corresponding to the insulation crimping portion 9 has a shape corresponding to the open barrel shape after crimping, and the portion corresponding to the conductor crimping portion 7 has a substantially circular cross section after crimping.

[0057] The conductor wire crimping blade die 32a is a blade die that corresponds to the wire holding portion 7a, and the conductor wire crimping blade die 32b is a blade die that corresponds to the conductive portion 7b. That is, the diameter of the conductor wire crimping blade die 32a is smaller than the diameter of the conductor wire crimping blade die 32b, and the distance between the upper blade die 31a and the lower blade die 31b in the portion that corresponds to the wire holding portion 7a is narrower than the distance between the upper blade die 31a and the lower blade die 31b in the portion that corresponds to the conductive portion 7b.

[0058] 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.

[0059] As shown in FIG. 8(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 coating crimping portion 9 is crimped onto the coating portion 15. In the tubular conductor crimping portion 7, the conductor wire 13 is crimped into a substantially circular shape, while in the open-barrel coating crimping portion 9, a pair of opposing barrel pieces are butted together at the substantially center in the width direction at the top of the coating crimping portion 9, and the coating crimped portion 15 is crimped by being folded into the interior of the coating crimping portion 9. At this time, the wire holding portion 7a has the smallest diameter, followed by the conductive portion 7b, and the coating crimping portion 9 has the largest diameter. In this manner, the electric wire with terminal 10 can be obtained. Furthermore, a wire harness can be obtained 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 is smaller than that of the conductive portion 7b, and the compression ratio of the coating crimping portion 9 is smaller than that of the conductive portion 7b. Here, if the cross-sectional area of ​​the coating portion 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 step (the total cross-sectional area of ​​the conductor 13 including the tensile strength members, if any) is A1, and the internal cross-sectional areas of the conductive portion 7b and the wire holding portion 7a after being compressed by the upper blade dies 31a and lower blade dies 31b (the total cross-sectional area of ​​the conductor 13 including the tensile strength members, if any) are A3 and A4, respectively, then the compression ratio of the wire holding portion 7a = A4 / A1 (%), and the compression ratio of the conductive portion 7b = A3 / A1 (%). Note that when the entire conductor crimping portion 7 is compressed under constant conditions, only one of the conductor crimping blade dies 32a, 32b is sufficient.

[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] Here, when the strength member 17 is formed from multiple strands, each strand is smaller than the conductor constituting the conductor wire 13, making it difficult to clearly distinguish between the strength member strands and the gaps between them. Therefore, the cross-sectional area of ​​the strength member 17 before crimping is defined as the area of ​​the region of the strength member surrounded by the conductor wire 13. In this case, in the early stages of compression, the strength member deforms so as to reduce the gaps between the strength member strands, while the conductor wire 13 deforms. In the later stages of compression, there is almost no reduction in the cross-sectional area of ​​the strength member, and the cross-sectional area of ​​the conductor wire 13 mainly decreases. Therefore, the compression ratio of the conductor wire 13 after crimping is equal to or less than the apparent compression ratio of the region where the strength member 17 is located. The area ratio of the conductor wire 13 to the strength member 17 after compression varies depending on the compression ratio of the entire electric wire.

[0064] 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.

[0065] Furthermore, since the amount of deformation of the tension 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, the tension members 17 are compressed from the entire periphery, and the tension members 17 are positioned between the conductor wire crimping portion 7, and the tension members 17 and the conductor wire crimping portion 7 do not come into contact with each other, so the tension members 17 are not damaged.

[0066] During compression, some of the wires constituting the strength member 17 may get caught between the conductor wires 13, causing part of the strength member 17 to come into contact with the conductor crimping portion 7. As mentioned above, it is desirable that the strength member 17 and the conductor crimping portion 7 do not come into contact, but it is acceptable for part of the strength member 17 to come into slight contact with the conductor crimping portion 7. For example, in any cross section, if the circumferential length of the strength member 17 that is in contact with the conductor crimping portion 7 is 30% or less of the total circumferential length of the strength member 17, the effect of suppressing damage to the strength member 17 can be obtained.

[0067] As described above, according to this embodiment, the insulated conductor wire 11 is easily positioned in the crimping portion 5 because the insulated crimping portion 9 is an open barrel type. Furthermore, the insulated conductor wire 11 can be easily positioned relative to the conductor crimping portion 7 in the insulated crimping portion 9, so the conductor wire 13 can be easily inserted into the conductor crimping portion 7 even if the conductor crimping portion 7 is tubular. As described above, the conductor crimping portion 7 is tubular, so the conductor wire 13 can be reliably crimped from all 360° of its circumference. Furthermore, the conductor wire 13 can be inserted even if the diameter of the conductor crimping portion 7 is small, so the size of the terminal after crimping can be reduced. As a result, the terminal can be easily inserted into the connector.

[0068] 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.

[0069] 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 tension member 17 may not fully exhibit its tensile strength. 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 wire crimping portion 7, the compressive stress on the tension member 17 can be partially increased, preventing pull-out.

[0070] Furthermore, if the conductor crimping portion 7 is cylindrical and has a brazed portion at the joint, a brazed portion with low hardness will have a smaller compressive stress on the conductor 13, making it easier to pull out the reinforcing 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.

[0071] In addition, by forming a terminal processing portion 19 at the tip of the conductor 13 or leaving the covering portion 15a, it is possible to prevent the conductor 13 from coming apart when inserting the conductor 13 into the conductor crimping portion 7.

[0072] Furthermore, since the conductor crimping portion 7 has the electric wire holding portion 7a and the conductive portion 7b, the electric wire holding portion 7a can be crimped at a compression rate suitable for ensuring connection strength, and the conductive portion 7b can be crimped at a compression rate suitable for ensuring conductivity. In other words, the compression rates (amounts of compression) of the electric wire holding portion 7a and the conductive portion 7b can be made different, so that each portion can be crimped at a compression rate suitable for its purpose.

[0073] More specifically, by forming the tip end side (terminal body 3 side) of the conductor crimping portion 7 as the wire holding portion 7a, stronger crimping can be performed, ensuring high connection strength. At this time, it is acceptable for part of the conductor wire 13 to break. On the other hand, because the conductive portion 7b is located on the rear end side (covering portion 15 side) of the conductor crimping portion 7, even if part of the conductor wire 13 breaks at the wire holding portion 7a, electrical continuity between the covered conductor wire 11 and the terminal 1 can be ensured.

[0074] Furthermore, the crimping operation can be performed in the same manner as for crimping a normal electric wire with a terminal, making the operation easy. In particular, the present invention can be applied to a coated conductor 11 including a tension member 17. In this case, high connection strength can be ensured even for a thin coated conductor 11.

[0075] 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.

[0076] (Second embodiment) Next, a second embodiment will be described. Fig. 9 is a perspective view of a terminal 1a according to the second embodiment before the coated conductor wire 11 is crimped. In the following description, components that have the same functions as those in the first embodiment are denoted by the same reference numerals as in Figs. 1 to 8, and redundant description will be omitted.

[0077] Terminal 1a has a configuration substantially similar to that of terminal 1, but differs in the shape of the crimping portion 5. Before crimping, terminal 1a has a wire holding portion 7a provided at the tip side of the conductor crimping portion 7, and a conductive portion 7b for establishing electrical continuity with the conductor at the rear end side of the conductor crimping portion 7, with the wire holding portion 7a and the conductive portion 7b being separated by a slit. In this case, the wire holding portion 7a and the conductive portion 7b may have different diameters.

[0078] The terminal 1a can be crimped in the same manner as the terminal 1, etc. In this way, by forming the wire holding portion 7a and the conductive portion 7b in the conductor crimping portion 7 and crimping them, the same effects as those of the first embodiment, etc. can be obtained.

[0079] (Third embodiment) Next, a third embodiment will be described. Fig. 10 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 differs in that the wire holding portion 7a of the conductor crimping portion 7 is tubular, and the conductive portion 7b and the insulation crimping portion 9 of the conductor crimping portion 7 are open barrel types. As such, as long as at least a portion of the conductor crimping portion 7 is tubular and closed in the circumferential direction, other portions may be open barrel types.

[0080] Terminal 1b can also be crimped in the same manner as terminal 1. Fig. 11 is a plan view showing a terminal-attached electric wire 10a in which terminal 1b and covered conductor wire 11 are crimped together. In terminal 1b, tubular electric wire holding portion 7a, open-barrel type conductive portion 7b, and insulation crimping portion 9 are each crimped to each portion of covered conductor wire 11. In this case, as described above, the compression ratio of electric wire holding portion 7a is smaller than that of conductive portion 7b.

[0081] Here, in the open barrel type conductive portion 7b and the coating crimping portion 9, at least one pair of opposing barrel pieces are folded to crimp the conductive wire 13 and the coating portion 15, respectively. In this case, in this embodiment, the opposing barrel pieces are not butted against each other but are shifted from each other in the axial direction of the crimping portion and arranged in a staggered pattern.

[0082] In this way, an open barrel type crimping portion having barrel pieces arranged in a staggered pattern generally allows for reliable crimping by bringing the barrel pieces into close contact with the crimping object without damaging the crimping object, but has the characteristic that it is difficult to obtain high connection strength. For this reason, in this embodiment, by making the wire holding portion 7a tubular and performing strong crimping, high connection strength is ensured, and by making the conductive portion 7b a staggered open barrel type, conductivity with the conductor 13 inside can be reliably ensured without damaging the conductor 13.

[0083] In this way, by forming and crimping the wire holding portion 7a and the conductive portion 7b in the wire crimping portion 7, it is possible to obtain the same effects as in the first embodiment, etc. In particular, by making at least a part of the wire crimping portion 7, such as the wire holding portion 7a that requires high connection strength, into a tubular shape that is closed in the circumferential direction, it is possible to obtain high holding force, and by making the conductive portion 7b into an open barrel type, it is possible to reduce electrical resistance.

[0084] Note that the arrangement of the barrel pieces of at least one of the conductive portion 7b and the coating crimping portion 9 may not be staggered, but may be arranged in opposing positions and crimped so that the barrel pieces overlap each other. In this case, the tips of the opposing barrel pieces are not butted together, but the opposing barrel pieces are overlapped and crimped so that one barrel piece wraps around the other barrel piece. In this way, the open barrel type crimping format is not particularly limited. [Example]

[0085] Various types of electric wires with terminals were prepared, and the ease of inserting the coated conductor into the terminal and the ease of inserting the obtained electric wires with terminal into the connector were evaluated. The conditions and evaluation results are shown in Tables 1 to 4.

[0086] [Table 1]

[0087] [Table 2]

[0088] [Table 3]

[0089] [Table 4]

[0090] The cross-sectional area of ​​the electric wire is the total cross-sectional area of ​​the conductor wire in a cross section perpendicular to the longitudinal direction of the electric wire. In Example 7, the cross-sectional area of ​​the conductor wire is the same as in Example 6, but the conductor wire was manufactured with the coating remaining at the tip of the conductor wire (see Figure 7(a)), and the cross-sectional area including the coating is shown in the table. The number of strands is the number of conductor wires. Those with a "-" tension member do not have a tension member, as in Figures 3(a) and 3(b). Those with a "Yes" tension member have a tension member in the center, with the conductor wires arranged around the tension member, as in the cross section shown in Figure 3(c). In both cases, multiple annealed copper conductor wires were used, twisted together.

[0091] "Circular compression" of the terminal processing section is performed by compressing the conductor from the outer periphery, as shown in Figure 5(c). "Circular compression + batch plating" is performed by forming a plating layer all at once from the outer periphery. "Circular compression + arc welding" is performed by compressing the conductor from the outer periphery and then arc welding the tip. "Circular compression + ultrasonic soldering" is performed by compressing the conductor from the outer periphery and then soldering the tip of the conductor together.

[0092] Terminals with a "tubular" wire crimp and an "open barrel" insulation crimp are similar to terminal 1 shown in Figure 4, while terminals with both a "tubular" wire crimp and an "open barrel" insulation crimp are tubular in shape and have an integrally formed crimp.

[0093] The cross-sectional area of ​​the conductor crimped portion before crimping is the cross-sectional area of ​​the internal space of the tubular conductor crimped portion before crimping in a cross section perpendicular to the conductor insertion direction. The cross-sectional area of ​​the conductor / cross-sectional area of ​​the crimped portion (%) is the ratio of the cross-sectional area of ​​the conductor to the cross-sectional area of ​​the conductor crimped portion before crimping. Note that only in Example 7 is this the ratio of the cross-sectional area of ​​the conductor including the coating to the cross-sectional area of ​​the conductor crimped portion before crimping.

[0094] Regarding ease of insertion into the terminal, when the tip of the conductor wire was inserted into the tubular conductor crimping portion, the tip of the conductor wire did not come apart or get caught, and the conductor wire could be easily inserted into the conductor crimping portion, it was evaluated as ⊚; when there was some catching, the conductor wire could be inserted into the conductor crimping portion, it was evaluated as ○; and when it was difficult to insert the conductor wire into the conductor crimping portion, such as when the tip of the conductor wire came apart, it was evaluated as ×.

[0095] Regarding the ease of insertion into the connector, when inserting the crimped terminal into the connector, if it was easy to insert into the connector, it was marked as ◯, and if it was difficult to insert, it was marked as x.

[0096] As can be seen from Tables 1 to 3, Examples 1 to 16, in which the insulation crimping portion was open barrel-shaped compared to the tubular wire crimping portion, all exhibited good insertability into the terminal, even though the ratio of the conductor cross-sectional area to the crimping portion cross-sectional area (%) was 40% or more. In particular, by not only compressing the tip of the conductor but also integrating it by leaving part of the insulation or by plating, arc welding, soldering, etc., it was possible to reliably prevent the conductor from coming apart and increase the rigidity of the tip of the conductor, resulting in good insertability into the terminal. For example, Example 7, in which part of the insulation was left, exhibited good insertability, even though the ratio of the cross-sectional area including the insulation to the crimping portion cross-sectional area was 70% or more.

[0097] In this way, in all of Examples 1 to 16, the conductor was placed in the open barrel-type insulation crimping portion, and after positioning relative to the conductor crimping portion, the conductor could be inserted into the conductor crimping portion. Therefore, even if the diameter of the conductor crimping portion was small compared to the diameter of the conductor, the conductor could be easily inserted into the conductor crimping portion. Furthermore, since the diameter of the conductor crimping portion could be made small, subsequent insertion into the connector was also easy.

[0098] On the other hand, in Comparative Example 1, since both the conductor crimping portion and the covering crimping portion were tubular, it was not easy to position the covered conductor in the tubular crimping portion, and it was difficult to insert the conductor into the tubular crimping portion. In Comparative Examples 2 and 3, the diameter of the conductor crimping portion was increased compared to Comparative Example 1, thereby improving the ease of inserting the conductor. However, as a result, the terminal size was increased, and the connector (1.25 mm 2 Cross-sectional area of ​​the connector insertion port for conductors: 3.2 mm 2 ) insertion into the catheter became difficult.

[0099] Similarly, in Comparative Example 4, both the conductor crimping portion and the insulation crimping portion were tubular, making it difficult to position the conductor and inserting the conductor into the tubular crimping portion. In Comparative Example 5, the diameter of the conductor crimping portion was increased compared to Comparative Example 4, thereby improving the ease of inserting the conductor. However, this resulted in a larger terminal size, and the connector (0.05 mm 2 Cross-sectional area of ​​the connector insertion port for the conductor: 0.125 mm 2 ) insertion into the catheter became difficult.

[0100] 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.

[0101] For example, in the above description, an example was shown in which the conductor wires 13 were arranged in one layer around the outer periphery of the tension member 17, but the arrangement of the conductor wires 13 is not limited to this. As long as the conductor wires 13 are arranged on the outer periphery of the tension member 17, the conductor wires 13 may be arranged in two layers around the tension member 17 as shown in FIG. 12(a), or may be arranged in three layers around the tension member 17 as shown in FIG. 12(b). Furthermore, from the viewpoint of the conductivity and strength of the conductor wires 13 themselves, the number of conductor wires 13 in the layer in contact with the tension member 17 should be three or more, and preferably 20 or less. For example, the number may be 12 or 14 as shown in FIGS. 5, 6, 12, etc., or may be six or eight. [Explanation of symbols]

[0102] 1, 1a, 1b....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, 10a...wire with terminal 11....Covered conductor 13……Conducting wire 15, 15a... Covering part 17……Tensile strength body 19...Terminal processing section 21: Plating layer 31a……Top blade type 31b……Lower blade type 32a, 32b.... 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, at least a portion of the conductor crimping portion has a circumferentially closed tubular shape and the insulation crimping portion has an open barrel shape; a wire holding portion is provided at a front end side of the conductor crimping portion, and a conductive portion for establishing electrical continuity with the conductor is formed at a rear end side of the conductor crimping portion, The coated conductor wire includes a plurality of the conductor wires and at least one strength member, The wire holding portion holds both the conductor wire, at least a portion of which is broken, and the tension member, The conductive wire is not broken at the conductive portion, The electrical resistance of the conductor in the conductive portion is lower than the electrical resistance of the conductor in the wire holding portion. A terminal-attached electric wire characterized by:

2. The electric wire with terminal according to claim 1, wherein the inner surface of the conductor crimping portion is provided with irregularities.

3. the strength members include fibers; 3. The electric wire with terminal according to claim 1, wherein a part of the fibers of the tension member enters into a gap in the broken conductor.

4. The electric wire with terminal according to any one of claims 1 to 3, wherein a compressibility of the electric wire holding portion is smaller than a compressibility of the conductive portion.

5. 5. The electric wire with terminal according to claim 1, wherein, 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 disposed on the outer periphery of the strength member.

6. 6. The electric wire with terminal according to claim 5, wherein the conductor wire is twisted in the longitudinal direction of the coated conductor wire.

7. The electric wire with terminal according to any one of claims 1 to 6, characterized in that at least the tip of the conductor is compressed from the outer periphery side, or the conductor is plated all at once from the outer periphery.

8. The electric wire with terminal according to any one of claims 1 to 7, characterized in that the cross-sectional area of ​​the conductor wire is 0.35 mm2 or less.

9. The electric wire with terminal according to any one of claims 1 to 8, characterized in that the cross-sectional area of ​​the conductor wire is 0.3 mm2 or less.

10. A wire harness comprising a plurality of electric wires with terminals integrated together, the electric wire with terminal comprising the electric wire with terminal according to any one of claims 1 to 9.

11. A method for manufacturing an electric wire with terminal according to any one of claims 1 to 9, A method for manufacturing an electric wire with a terminal, wherein the cross-sectional area inside the covering portion is 40% or more of the cross-sectional area of ​​the insertion portion of the conductor crimping portion before crimping.

12. 12. The method for manufacturing an electric wire with a terminal according to claim 11, wherein when removing the coating from the tip of the coated conductor, the conductor is inserted into the conductor crimping portion with a portion of the coating remaining on the tip, and the coating is removed from the conductor before crimping.

Images