Terminal-equipped electric wire, terminal, and method for manufacturing terminal-equipped electric wire

Abstract

The present invention provides a technology in which satisfactory crimping between a terminal and a core wire is achieved. This terminal-equipped electric wire comprises: an electric wire including a core wire; and a terminal to be crimped to the core wire. The terminal includes a tubular portion. The tubular portion has: a crimping portion to be subjected to crimping to the core wire; and an electric wire support portion positioned adjacent to the crimping portion. The electric wire support portion supports the core wire from the outer side in the circumferential direction of the core wire so as to maintain the position of the core wire relative to the crimping portion in a direction orthogonal to the longitudinal direction of the core wire.

Description

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

[0001] The present disclosure relates to a terminal-attached electric wire, a terminal, and a method for manufacturing a terminal-attached electric wire.

[0002] Patent Document 1 discloses an electric wire with a terminal that is pressure-welded by electromagnetic pressure welding. The method for manufacturing an electric wire with a terminal described in Patent Document 1 uses electromagnetic force to reduce the diameter of a cylindrical portion of the terminal, thereby pressure-welding the electric wire and the terminal.

[0003] Japanese Patent Application Laid-Open No. 2019-186082

[0004] In an electric wire with a terminal, it is desirable that the terminal and the core wire are press-connected together satisfactorily.

[0005] Therefore, an object of the present invention is to provide a technique for ensuring good pressure welding between a terminal and a core wire.

[0006] The terminal-equipped electric wire of the present disclosure comprises an electric wire including a core wire and a terminal that is crimped to the core wire, the terminal including a tubular portion, the tubular portion having a crimped portion that is crimped to the core wire, and a wire support portion located adjacent to the crimped portion, and the wire support portion supports the core wire from the circumferential outside so as to maintain the position of the core wire relative to the crimped portion in a direction perpendicular to the longitudinal direction of the core wire.

[0007] The terminal of the present disclosure includes a tubular portion, and the tubular portion includes a crimped portion and a wire support portion having an inner diameter smaller than the inner diameter of the crimped portion.

[0008] The method for manufacturing an electric wire with a terminal disclosed herein is a method for manufacturing an electric wire with a terminal that crimps a terminal and a core wire, and includes preparing a terminal having a tubular portion, the tubular portion including a crimping portion and a wire support portion having an inner diameter smaller than the inner diameter of the crimping portion, supporting the core wire in the wire support portion, and electromagnetically crimping the crimping portion to the core wire while the core wire is supported in the wire support portion.

[0009] According to the present disclosure, it is possible to provide a technique for properly crimping a terminal and a core wire together.

[0010] FIG. 1 is a perspective view showing a terminal-attached electric wire according to an embodiment. FIG. 2 is a cross-sectional view showing a cross section taken along line II-II in FIG. 1. FIG. 3 is a cross-sectional view showing a cross section taken along line III-III in FIG. 2. FIG. 4 is a cross-sectional view showing a terminal and an electric wire before pressure welding. FIG. 5 is an explanatory view showing the states before and after pressure welding in a cross section taken along line V-V in FIG. 4. FIG. 6 is a cross-sectional view showing a cross section corresponding to FIG. 2 of a terminal-attached electric wire of a modified example. FIG. 7 is a cross-sectional view showing a cross section corresponding to FIG. 2 of a terminal-attached electric wire of another modified example. FIG. 8 is a cross-sectional view showing a cross section corresponding to FIG. 3 of a terminal-attached electric wire of another modified example. FIG. 9 is a cross-sectional view showing a cross section corresponding to FIG. 3 of a terminal-attached electric wire of another modified example.

[0011] [Description of Embodiments of the Present Disclosure] First, embodiments of the present disclosure will be listed and described.

[0012] The electric wire with terminal, the terminal, and the method for manufacturing the electric wire with terminal according to the present disclosure are as follows.

[0013] (1) A terminal-equipped electric wire includes an electric wire including a core wire and a terminal that is crimped to the core wire, the terminal including a tubular portion, the tubular portion having a crimped portion that is crimped to the core wire, and a wire support portion located adjacent to the crimped portion, the wire support portion supporting the core wire from the circumferential outside of the core wire so as to maintain the position of the core wire relative to the crimped portion in a direction perpendicular to the longitudinal direction of the core wire.

[0014] According to the electric wire with terminal (1), the wire support portion supports the core wire from the circumferential outside thereof so as to maintain the position of the core wire relative to the crimping portion. Therefore, the crimping portion and the core wire are crimped together while maintaining the position of the core wire relative to the crimping portion before the crimping process. For example, the core wire can be supported so that a uniform gap is provided between the crimping portion and the core wire before the crimping process in the circumferential direction. In this way, the terminal and the core wire can be crimped together while a uniform gap is provided between the crimping portion and the core wire in the circumferential direction. This ensures good crimping between the crimping portion and the core wire. In particular, when the terminal and the core wire are crimped together by electromagnetic crimping, a uniform gap is provided between the crimping portion and the core wire before the crimping process in the circumferential direction, so that the terminal is squeezed at a uniform speed in the circumferential direction, thereby crimping the terminal and the core wire together. This facilitates crimping with uniform joint strength in the circumferential direction. Therefore, the terminal and the core wire are crimped together well.

[0015] (2) In the electric wire with terminal of (1), the wire support portion may protrude from the inner circumferential surface of the tubular portion toward the core wire. With this electric wire with terminal, the wire support portion protruding from the inner circumferential surface of the tubular portion makes it easy to support the core wire while providing a gap between the crimping portion and the core wire before crimping.

[0016] (3) In the electric wire with terminal of (1) or (2), the inner peripheral surface of the wire support portion may be in contact with the core wire over the entire circumference. With this electric wire with terminal, the wire support portion is in contact with the core wire over the entire circumference, so that the core wire can be more stably supported from the circumferential outer side of the core wire. Therefore, the positional relationship between the insulation displacement portion and the core wire in the direction perpendicular to the longitudinal direction of the core wire is maintained.

[0017] (4) In the electric wire with terminal according to (1) or (2), the wire support portion may include a plurality of protrusions protruding from the inner circumferential surface of the tubular portion toward the inside of the tubular portion. With this electric wire with terminal, the apexes of the plurality of protrusions come into contact with the core wire, so that the wire support portion can stably support the core wire from the circumferential outer side of the core wire. This further stably maintains the positional relationship between the insulation displacement portion and the core wire in a direction perpendicular to the longitudinal direction of the core wire.

[0018] (5) In the electric wire with a terminal according to any one of (1) to (4), the wire support portion may include a first wire support portion and a second wire support portion, and the insulation displacement processing portion may be located between the first wire support portion and the second wire support portion. With this electric wire with a terminal, the core wire is supported at two locations, the first wire support portion and the second wire support portion, so that the wire support portions can stably support the core wire from the circumferential outer side of the core wire.

[0019] (6) In the electric wire with terminal according to any one of (1) to (5), the core wire may be a single core wire. With this electric wire with terminal, the wire support portion presses the core wire into the press-fitted portion while maintaining the position of the core wire relative to the press-fitted portion before press-fitting in a direction perpendicular to the longitudinal direction of the core wire. Therefore, even if the core wire is a single core wire, which is usually difficult to change shape, the terminal and the core wire are press-fitted well.

[0020] (7) The terminal of the present disclosure also includes a tubular portion, the tubular portion including a crimping portion and a wire support portion having an inner diameter smaller than that of the crimping portion. With this terminal, a core wire having an outer diameter smaller than that of the crimping portion can be positioned within the crimping portion by the wire support portion. In this state, a stable gap is formed between the inner circumferential surface of the crimping portion and the core wire. In particular, when the terminal and the core wire are crimped together by electromagnetic pressure welding, a stable gap is provided between the crimping portion and the core wire before crimping, which facilitates stable crimping between the terminal and the core wire. This ensures good crimping between the terminal and the core wire.

[0021] (8) In the terminal of (7), the axial center of the insulation displacement portion and the axial center of the wire support portion may be coaxial. According to this terminal, the axial center of the insulation displacement portion and the axial center of the wire support portion are coaxially formed, so that the terminal and the core wire can be pressure-welded with a uniform gap between the insulation displacement portion and the core wire in the circumferential direction. This results in good pressure welding between the insulation displacement portion and the core wire. In particular, when the terminal and the core wire are pressure-welded by electromagnetic pressure welding, a uniform gap is provided between the insulation displacement portion and the core wire before pressure welding, so that the terminal is squeezed at a uniform speed in the circumferential direction, and the terminal and the core wire are pressure-welded. This facilitates pressure welding with uniform joint strength in the circumferential direction. This results in good pressure welding between the terminal and the core wire.

[0022] (9) A method for manufacturing an electric wire with a terminal according to the present disclosure is a method for manufacturing an electric wire with a terminal for crimping a terminal and a core wire, the method comprising the steps of: preparing a terminal having a tubular portion, the tubular portion including a crimping portion and a wire support portion having an inner diameter smaller than that of the crimping portion; supporting the core wire in the wire support portion; and electromagnetically crimping the crimping portion to the core wire while the core wire is supported by the wire support portion. According to this method for manufacturing an electric wire with a terminal, when a core wire having an inner diameter smaller than that of the crimping portion is positioned by the wire support portion, a gap is generated between the inner circumferential surface of the crimping portion and the core wire. In this state, the terminal and the core wire are crimped together by electromagnetic crimping, and since a gap is provided between the crimping portion and the core wire before crimping, the terminal and the core wire are electromagnetically crimped together while the core wire is stably positioned relative to the crimping portion, thereby achieving good crimping between the terminal and the core wire.

[0023] [Details of the embodiment of the present disclosure] Specific examples of the electric wire with terminal, the terminal, and the method for manufacturing the electric wire with terminal of the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0024] In the drawings, for the sake of convenience, some of the components may be exaggerated or simplified. Also, the dimensional ratios of the components may differ from one drawing to another. Furthermore, in this specification, "parallel" and "orthogonal" do not only refer to cases where the components are strictly parallel or orthogonal, but also include cases where the components are roughly parallel or orthogonal within the scope of the functions and effects of this embodiment.

[0025] [Embodiment] Hereinafter, a terminal-attached electric wire 10, a terminal 20, and a method for manufacturing the terminal-attached electric wire 10 according to an embodiment will be described. Fig. 1 is a perspective view showing the terminal-attached electric wire 10. Fig. 2 is a cross-sectional view showing a cross section taken along line II-II in Fig. 1. Fig. 3 is a cross-sectional view showing a cross section taken along line III-III in Fig. 2. Fig. 4 is a cross-sectional view showing a terminal and an electric wire before crimping. Fig. 5 is an explanatory view showing the state before and after crimping in a cross section taken along line V-V in Fig. 4. In Figs. 1 to 5, the core wire 32 is shown by a virtual line.

[0026] <Regarding the terminal-attached electric wire 10> The terminal-attached electric wire 10 includes a terminal 20 and an electric wire 30. The electric wire 30 includes a core wire 32 made of aluminum or an aluminum alloy. The core wire 32 may or may not be covered with an insulating material. The covering may be, for example, an insulating resin extruded and coated around the core wire 32. The terminal 20 is connected to the uncovered, exposed portion of the core wire 32. In this embodiment, the core wire 32 is a single-core wire. The core wire 32 is not limited to a single-core wire. The core wire 32 may be a twisted wire formed by twisting multiple conductors together.

[0027] <Regarding the terminal 20> The terminal 20 is a component made of copper or a copper alloy. The terminal 20 is formed, for example, by cutting out a base material of copper or a copper alloy. The terminal 20 may also be formed by other methods. For example, the terminal 20 may be formed by press-forming a copper or copper alloy plate. Furthermore, the terminal 20 is not limited to copper or a copper alloy. The material of the terminal 20 may also be a material that can be electromagnetically welded, such as aluminum, stainless steel, or tungsten.

[0028] The terminal 20 is a component that connects the core wire 32 of the electric wire 30 to a component to which it is to be connected. In this embodiment, the terminal 20 includes a tubular portion 22 and a mating connection portion 29. The mating connection portion 29 is linearly connected to the tip side of the tubular portion 22. The portion between the tubular portion 22 and the mating connection portion 29 may be curved.

[0029] An end of the core wire 32 is exposed at the end of the electric wire 30, and the core wire 32 is inserted into the cylindrical portion 22. The exposed end of the core wire 32 is held inside the cylindrical portion 22. An end face 32b of the core wire 32 faces the mating connection portion 29.

[0030] The cylindrical portion 22 has a crimped portion 24 and a wire support portion 26. The crimped portion 24 is the portion that is crimped to the core wire 32. The crimped portion 24 is a so-called closed barrel type. As shown in Fig. 4, the crimped portion 24 has a cylindrical shape before crimping. Furthermore, before crimping, the crimped portion 24 has an inner diameter R2 that is larger than the outer diameter R1 of the core wire 32 that is crimped to the cylindrical portion 22.

[0031] The wire support portion 26 supports the core wire 32 from the circumferential outer side of the core wire 32. As a result, the wire support portion 26 maintains the position of the core wire 32 relative to the insulation displacement portion 24 in a direction perpendicular to the longitudinal direction A of the core wire 32. In other words, the positional relationship between the insulation displacement portion 24 and the core wire 32 is maintained in a direction perpendicular to the longitudinal direction A of the core wire 32. The wire support portion 26 is located adjacent to the insulation displacement portion 24. In this embodiment, the wire support portion 26 has a bottomed tubular shape and includes a bottom portion 27 and an inner peripheral portion 28. In this embodiment, the wire support portion 26 has a cylindrical shape. The wire support portion 26 does not have to have a bottom, and may, for example, be open toward the mating connection portion 29. In addition, the wire support portion 26 does not have to have a cylindrical shape, and may, for example, have a rectangular tubular shape. However, it is preferable that the wire support portion 26 be configured to contact the entire circumference of a portion of the outer circumferential surface 32 a of the core wire 32 .

[0032] The inner peripheral portion 28 of the wire support portion 26 is a portion that protrudes from the inner peripheral surface 22a of the tubular portion 22 toward the core wire 32 (inside the tubular portion 22). In this embodiment, the inner peripheral surface 28a of the inner peripheral portion 28 of the wire support portion 26 contacts the core wire 32 over the entire circumference. A structure in which the wire support portion 26 contacts the core wire 32 over the entire circumference is employed, but is not limited to this. The wire support portion 26 may also have a structure in which it contacts only a portion of the core wire 32. Furthermore, in this embodiment, the inner diameter R3 of the inner peripheral portion 28 of the wire support portion 26 is the same size as the outer diameter R1 of the core wire 32. This allows the inner peripheral surface 26a of the wire support portion 26 and the outer peripheral surface 32a of the core wire 32 to fit together. 4, before the pressure welding process, the axis C1 of the pressure welding portion 24 and the axis C2 of the wire support portion 26 are coaxial (on the axis C of the tubular portion 22 in this embodiment). Due to this relationship between the pressure welding portion 24 and the wire support portion 26, a gap is generated between the inner circumferential surface 24a of the pressure welding portion 24 and the outer circumferential surface 32a of the core wire 32 before the pressure welding process. Furthermore, the wire support portion 26 can support the core wire 32 so that a uniform gap is formed between the pressure welding portion 24 and the core wire 32 in the circumferential direction before the pressure welding process. Due to this positional relationship between the pressure welding portion 24 and the core wire 32, the terminal 20 and the core wire 32 are well pressure-welded together when they are pressure-welded by electromagnetic pressure welding, which will be described in detail later.

[0033] In this embodiment, the bottom surface portion 27 contacts the end face 32b of the core wire 32. This maintains the positional relationship between the terminal 20 and the core wire 32 in a direction perpendicular to the longitudinal direction A, and also maintains the positional relationship between the terminal 20 and the core wire 32 in the longitudinal direction A. In this embodiment, the bottom surface portion 27 contacts the entire surface of the end face 32b. However, the structure is not limited to one in which the bottom surface portion 27 contacts the entire surface of the end face 32b. A structure in which the bottom surface portion 27 contacts a portion of the end face 32b may also be employed. Even in a structure in which the bottom surface portion 27 contacts a portion of the end face 32b, the core wire 32 can be positioned in the longitudinal direction A.

[0034] The mating connection portion 29 is a portion that is connected to a component to which the electric wire 30 is connected. In this embodiment, the mating connection portion 29 is a rod-shaped portion having a hole 29a. For example, it is conceivable that the mating connection portion 29 is screwed to the component to which it is connected. The component to which it is connected is assumed to be a terminal of an electrical device, a metal housing, a metal body of a vehicle, or the like. The mating connection portion 29 may be a pin-shaped or rod-shaped portion that is inserted into a cylindrical portion of a mating terminal, or a cylindrical portion into which a mating terminal is inserted. The mating connection portion 29 may be omitted. In this case, the terminal may be crimped to multiple electric wires. Such a terminal may be used as a terminal for connecting two electric wires.

[0035] <Regarding the Manufacturing Method of the Terminal-Attached Electric Wire 10> Hereinafter, a method of manufacturing the terminal-attached electric wire 10 will be described.

[0036] 5 , when manufacturing the terminal-attached electric wire 10, first, the core wire 32 is supported by the wire support portion 26 (wire supporting step). When the core wire 32 is supported by the wire support portion 26, the core wire 32 is disposed inside the tubular portion 22 so that the end surface 32 b of the core wire 32 is in contact with the bottom surface portion 27.

[0037] Once the core wire 32 is supported by the wire support portion 26 in the above-described wire supporting step, a portion of the insulation displacement processing portion 24 and the core wire 32 are electromagnetically welded together. More specifically, the insulation displacement processing portion 24 is placed together with the core wire 32 in an electromagnetic welding device 50. The electromagnetic welding device 50 includes a discharge coil 51. A discharge current indicated by an arrow 51i flows through the discharge coil 51. When the discharge current indicated by the arrow 51i flows, a magnetic field H is generated between the discharge coil 51 and a portion of the insulation displacement processing portion 24 in a direction perpendicular to the plane of the page in FIG. 5 . At this time, an induced electromotive force of the magnetic field H generates an induced current indicated by an arrow 24i in a portion of the insulation displacement processing portion 24. This, combined with the magnetic field H and the induced current indicated by the arrow 24i, acts on the portion of the insulation displacement processing portion 24 in the diameter-reducing direction indicated by an arrow F. This causes a diameter-reducing deformation of the portion of the insulation displacement processing portion 24 as shown by the imaginary line in FIG. 5 . This causes the portion of the insulation displacement processing portion 24 to be pressure-welded to the core wire 32. In this embodiment, a portion of the insulation displacement portion 24 is pressure-welded to the core wire 32, but the entire insulation displacement portion 24 may be pressure-welded to the core wire 32. In this embodiment, a portion of the insulation displacement portion 24 is pressure-welded to the core wire 32, so that a gap G1 is formed between the portion of the insulation displacement portion 24 where the core wire 32 is pressure-welded and between the wire support portion 126 and the core wire 32. A gap G2 is also formed between the insulation displacement portion 24 and the core wire 32 near the opening of the tubular portion 22 of the terminal 20.

[0038] As described above, in this embodiment, electromagnetic pressure welding is performed with the core wire 32 supported by the wire support portion 26. Electromagnetic pressure welding has traditionally required a jig or the like to maintain the positional relationship between the pressure welding portion 24 and the core wire 32. Such a jig or the like has traditionally required high precision to maintain the positional relationship between the pressure welding portion 24 and the core wire 32. Furthermore, in electromagnetic pressure welding, the pressure welding portion 24 collides with the core wire 32 at a speed close to the speed of sound, so the jig or the like wears out quickly. However, in this embodiment, the positional relationship between the pressure welding portion 24 and the core wire 32 is maintained by the wire support portion 26, so no jig or the like is required. However, an auxiliary jig may be used.

[0039] During pressure welding by this electromagnetic pressure welding device 50, a portion of the pressure welding portion 24 collides with the core wire 32 at a speed close to the speed of sound. It is expected that if the core wire 32 is left in the air, an oxide film will form on its surface. Similarly, if the terminal 20 is left in the air, an oxide film will form on its surface. It is expected that the oxide film formed on the surfaces of the core wire 32 and the terminal 20 will be removed by the portion of the pressure welding portion 24 colliding with the core wire 32 at a speed close to the speed of sound. This results in good pressure welding between the portion of the pressure welding portion 24 and the core wire 32.

[0040] Furthermore, in this embodiment, before the crimping process, the axis C1 of the crimped portion 24 and the axis C2 of the wire support portion 26 are coaxial, and therefore the wire support portion 26 supports the core wire 32 so that a uniform gap is formed between the crimped portion 24 and the core wire 32 in the circumferential direction before the crimping process. This support is expected to reduce the bias in the electromagnetic force required for crimping a portion of the crimped portion 24 and the core wire 32 in the circumferential direction. This is expected to result in the crimping of a portion of the crimped portion 24 and the core wire 32 at a uniform speed in the circumferential direction. Therefore, it is expected that the crimping of a portion of the crimped portion 24 and the core wire 32 is uniform in the circumferential direction.

[0041] Furthermore, if the distance between the pressure-welding portion 24 and the core wire 32 before pressure welding is short, the pressure-welding portion 24 and the core wire 32 will come into contact before reaching a speed close to the speed of sound. On the other hand, if the distance between the pressure-welding portion 24 and the core wire 32 before pressure welding is long, the pressure-welding portion 24 and the core wire 32 will come into contact at a slower speed after reaching a speed close to the speed of sound. For this reason, it is preferable that the distance between the pressure-welding portion 24 and the core wire 32 before pressure welding is a distance appropriate for the pressure-welding portion 24 and the core wire 32 to come into contact at a speed close to the speed of sound. It is also preferable that the pressure-welding portion 24 and the core wire 32 before pressure welding be arranged with an equal gap between them in the circumferential direction.

[0042] <Effects of the Embodiments> According to the electric wire with terminal 10, the terminal 20, and the manufacturing method of the electric wire with terminal 10 configured as described above, the wire support portion 26 supports the core wire 32 from the circumferential outside of the core wire 32 so as to maintain the position of the core wire 32 relative to the insulation displacement portion 24 in a direction perpendicular to the longitudinal direction A of the core wire 32. As a result, the insulation displacement portion 24 and the core wire 32 are pressure-welded together while maintaining the position of the core wire 32 relative to the insulation displacement portion 24 in a direction perpendicular to the longitudinal direction A before the insulation displacement process. For example, the core wire 32 can be supported so that a uniform gap is provided between the insulation displacement portion 24 and the core wire 32 in the circumferential direction before the insulation displacement process. In this way, the terminal 20 and the core wire 32 can be pressure-welded together with a uniform gap provided between the insulation displacement portion 24 and the core wire 32 in the circumferential direction. As a result, the insulation displacement portion 24 and the core wire 32 are pressure-welded together well. In particular, when the terminal 20 and the core wire 32 are pressure-welded by electromagnetic pressure welding, a uniform gap is provided in the circumferential direction between the pressure-welding processed portion 24 and the core wire 32 before pressure welding, so that the terminal 20 and the core wire 32 are pressure-welded at a uniform speed in the circumferential direction. This facilitates pressure welding with uniform joint strength in the circumferential direction. Therefore, the terminal 20 and the core wire 32 are pressure-welded well.

[0043] Furthermore, the wire support portion 26 protrudes from the inner peripheral surface 22a of the cylindrical portion 22 toward the axis C of the cylindrical portion 22. This allows the terminal 20 to stably support the core wire 32 from the circumferential outer side of the core wire 32. This allows the positions of the wire support portion 26 and the core wire 32 in the direction perpendicular to the longitudinal direction A to be maintained more stably.

[0044] Furthermore, the inner peripheral surface of the wire support portion 26 (the inner peripheral surface 28a of the inner peripheral portion 28) contacts the core wire 32 over the entire circumference. This allows the core wire 32 to be more stably supported from the circumferential outside of the core wire 32. This allows the positional relationship between the wire support portion 26 and the core wire 32 in the direction perpendicular to the longitudinal direction A to be maintained more stably.

[0045] Furthermore, the core wire 32 is a single-core wire. Compared to a conductor formed by bundling multiple conductors, such as a twisted wire, a single-core wire is more difficult to change shape. This makes it difficult to increase the strength of the crimped joint between the terminal 20 and the single-core wire. However, in this embodiment, the crimped portion 24 and the core wire 32 are crimped together while maintaining the position of the core wire 32 in a direction perpendicular to the longitudinal direction A of the crimped portion 24 before crimping. At this time, if there is an appropriate gap between the core wire 32 and the crimped portion 24, the crimped portion 24 is squeezed at high speed. This ensures good crimping between the crimped portion 24 and the core wire 32.

[0046] Furthermore, the inner diameter R2 of the insulation displacement portion 24 is larger than the outer diameter R1 of the core wire 32 to be pressure-welded to the tubular portion 22, and the inner diameter R3 of the wire support portion 26 is smaller than the inner diameter R2 of the insulation displacement portion 24. Because the inner diameter R2 of the insulation displacement portion 24 is larger than the outer diameter R1 of the core wire 32, a gap is generated between the inner circumferential surface 24a of the insulation displacement portion 24 and the outer circumferential surface 32a of the core wire 32 before pressure welding. In particular, when the terminal 20 and the core wire 32 are pressure-welded by electromagnetic pressure welding, providing an appropriate gap between the insulation displacement portion 24 and the core wire 32 before pressure welding makes it easier for the terminal and the core wire to be pressure-welded at a speed close to the speed of sound. This ensures good pressure welding between the terminal 20 and the core wire 32.

[0047] Furthermore, the axis C1 of the insulation displacement portion 24 and the axis C1 of the wire support portion 26 are coaxial. As a result, the insulation displacement portion 24 and the core wire 32 are pressure-welded together with a uniform gap between them in the circumferential direction before the pressure welding process. This ensures good pressure welding between the insulation displacement portion 24 and the core wire 32. In particular, when the terminal 20 and the core wire 32 are pressure-welded together by electromagnetic pressure welding, if a uniform gap is provided between the insulation displacement portion 24 and the core wire 32 in the circumferential direction before the pressure welding process, the insulation displacement portion 24 and the core wire 32 are pressure-welded together at a uniform speed in the circumferential direction of the core wire 32. Therefore, the insulation displacement portion 24 and the core wire 32 are likely to be pressure-welded together with uniform joint strength in the circumferential direction of the core wire 32. This ensures good pressure welding between the terminal 20 and the core wire 32.

[0048] The manufacturing method for the terminal-attached electric wire 10 of this embodiment uses a terminal 20 in which the inner diameter R2 of the insulation displacement processed portion 24 is larger than the outer diameter R1 of the core wire 32 to be pressure-welded to the tubular portion 22 and the inner diameter R3 of the wire support portion 26 is smaller than the inner diameter R2 of the insulation displacement processed portion 24. The manufacturing method for the terminal-attached electric wire 10 of this embodiment includes a wire supporting step in which the core wire 32 is supported by the wire support portion 26, and an electromagnetic pressure welding step in which, with the core wire 32 supported by the wire support portion 26 in the wire supporting step, part or all of the insulation displacement processed portion 24 is electromagnetically pressure-welded to the core wire 32. As a result, the terminal 20 and the core wire 32 are pressure-welded by electromagnetic pressure welding in a state in which a gap is generated between the inner circumferential surface 24a of the insulation displacement processed portion 24 and the outer circumferential surface 32a of the core wire 32 before pressure welding. Therefore, by providing an appropriate gap between the insulation displacement processed portion 24 and the core wire 32, the terminal and the core wire can be easily pressure-welded together at a speed close to the speed of sound, thereby ensuring good pressure welding between the terminal 20 and the core wire 32.

[0049] [Modification 1] Hereinafter, a terminal-attached electric wire 110 according to Modification 1 of the present embodiment will be described. Fig. 6 is a cross-sectional view showing a cross section of the terminal-attached electric wire 110 of Modification 1 corresponding to Fig. 2 (a cross section taken along line II-II in Fig. 1).

[0050] The terminal-attached electric wire 110 according to the first modification differs from the terminal-attached electric wire 10 in that it includes a terminal 120 instead of the terminal 20. The terminal 120 has the same insulation displacement processed portion 24 as that of the terminal 20, and a wire support portion 126. The wire support portion 126 has a bottomed cylindrical shape, including a bottom surface portion 127 and an inner peripheral portion 128. In the first modification, the inner peripheral portion 128 of the wire support portion 126 has a tapered shape that tapers toward the bottom surface portion 127. In the first modification, the inner diameter R4 of the bottom surface portion 127 is a dimension that can support the core wire 32. The inner diameter R4 is formed to be the same dimension as the outer diameter R1, for example. In the first modification, the bottom surface portion 127 is structured to contact the entire end surface 32b. However, the structure is not limited to the bottom surface portion 127 contacting the end surface 32b. For example, the inner diameter of a portion of the inner circumferential surface 128a of the inner circumferential portion 128 is sized to support the core wire 32. In other words, a structure may be adopted in which the inner diameter of a portion of the inner circumferential portion 128 has the same dimension as the outer diameter R1 of the core wire 32, and the end of the core wire 32 is supported by the inner circumferential surface 128a of the portion of the inner circumferential portion 128. Even with this structure, the wire support portion 126 maintains the positional relationship between the terminal 20 and the core wire 32 in a direction perpendicular to the longitudinal direction A, and also maintains the positional relationship between the terminal 120 and the core wire 32 in the longitudinal direction A. When electromagnetic pressure welding is performed in this state, a portion of the pressure-welded portion 24 is deformed by reducing its diameter as shown by the imaginary line. This results in good pressure welding between the pressure-welded portion 24 and the core wire 32.

[0051] According to the terminal 120 of the first modified example, no step is formed between the insulation displacement processed portion 24 and the wire support portion 126. As a result, the core wire 32 is smoothly supported by the wire support portion 126 of the terminal 120 without being caught by a step. Also, the outer diameter R1 of the core wire 32 only needs to be the same as the inner diameter of one of the inner peripheries 128 of the wire support portion 126, which widens the range of options for the outer diameter of the core wire 32.

[0052] In the first modification, a gap G3 is also formed between a part of the insulation displacement processed portion 24 that is pressure-welded to the core wire 32, the wire support portion 126, and the core wire 32.

[0053] [Modification 2] Hereinafter, a terminal-attached electric wire 210 according to Modification 2 of the present embodiment will be described. Fig. 7 is a cross-sectional view showing a cross section of the terminal-attached electric wire 210 of Modification 2 corresponding to Fig. 2 (a cross section taken along line II-II in Fig. 1).

[0054] The terminal-attached electric wire 210 according to the second modification example differs from the terminal-attached electric wire 10 in that it includes a terminal 220 instead of the terminal 20. The terminal 220 includes an insulation displacement portion 224 and a wire support portion 226. The wire support portion 226 includes a first wire support portion 226a and a second wire support portion 226b. The first wire support portion 226a and the second wire support portion 226b are disposed at different positions in the longitudinal direction A of the core wire 32. The insulation displacement portion 224 is disposed between the first wire support portion 226a and the second wire support portion 226b.

[0055] The first wire support portion 226a and the second wire support portion 226b support the core wire 32 from the circumferential outside of the core wire 32. Because the core wire 32 is supported by the two wire support portions 226, the positional relationship between the insulation displacement portion 24 and the core wire 32 is maintained more stably than in the case of a single wire support portion 26. In the present modified example 2, the two wire support portions 226 also have a cylindrical shape. Note that the first wire support portion 226a has a bottom portion 227, similar to the wire support portion 26 of the embodiment.

[0056] In the present second modification, a gap G4 is formed between a part of the insulation displacement processed portion 224 that is pressure-welded to the core wire 32, the first wire support portion 226a, and the core wire 32. Also, a gap G5 is formed between a part of the insulation displacement processed portion 224 that is pressure-welded to the core wire 32, the second wire support portion 226b, and the core wire 32.

[0057] In addition, in this modified example 2, the wire support portion 226 includes two wire support portions 226, a first wire support portion 226a and a second wire support portion 226b, but the wire support portions may be arranged at three or more different positions in the longitudinal direction A of the core wire 32.

[0058] [Modification 3] Hereinafter, a terminal-attached electric wire 310 according to Modification 3 of the present embodiment will be described. Fig. 8 is a cross-sectional view showing a cross section of the terminal-attached electric wire 310 of Modification 3 corresponding to Fig. 3 (a cross section taken along line III-III in Fig. 2).

[0059] The terminal-attached electric wire 310 according to the third modification differs from the terminal-attached electric wire 10 in that it includes a terminal 320 instead of the terminal 20. The terminal 320 includes a tubular portion 322. The tubular portion 322 includes the insulation displacement portion 24 and a wire support portion 326. The wire support portion 326 includes a plurality of protrusions 328 that protrude from an inner circumferential surface 322a of the tubular portion 322 toward the inside of the tubular portion 322. In the third modification, the protrusions 328 include two protrusions 328: a first protrusion 328a and a second protrusion 328b.

[0060] The first protrusion 328a and the second protrusion 328b are arranged on the inner circumferential surface 322a of the cylindrical portion 322 at positions facing each other in a direction perpendicular to the longitudinal direction A of the core wire 32. The first protrusion 328a and the second protrusion 328b have a circumferential length sufficient to clamp the core wire 32. The first protrusion 328a and the second protrusion 328b each have a contact surface 327 that contacts the core wire 32 over a length that is, for example, ⅕ or more of the outer periphery of the core wire 32. The contact surface 327 is formed in an arc shape so as to follow the outer periphery of the core wire 32. As a result, the core wire 32 is stably supported even with two protrusions 328.

[0061] [Modification 4] Hereinafter, a terminal-attached electric wire 410 according to Modification 4 of the present embodiment will be described. Fig. 8 is a cross-sectional view showing a cross section of a terminal-attached electric wire 310 according to Modification 3, corresponding to Fig. 3 (a cross section taken along line III-III in Fig. 2).

[0062] The terminal-attached electric wire 410 according to the fourth modification differs from the terminal-attached electric wire 10 in that it includes a terminal 420 instead of the terminal 20. The terminal 420 includes a tubular portion 422. The tubular portion 422 includes the insulation displacement portion 24 and a wire support portion 426. The wire support portion 426 includes a plurality of protrusions 428 that protrude from an inner circumferential surface 422a of the tubular portion 422 toward the inside of the tubular portion 422. In the fourth modification, the protrusions 428 include three protrusions 428: a first protrusion 428a, a second protrusion 428b, and a third protrusion 428c.

[0063] The first protrusion 428a, the second protrusion 428b, and the third protrusion 428c are arranged on the inner circumferential surface 422a of the cylindrical portion 422 at positions on the same plane perpendicular to the longitudinal direction A of the core wire 32. The first protrusion 428a, the second protrusion 428b, and the third protrusion 428c are arranged at equal intervals. As a result, even with three protrusions 428, the core wire 32 is stably supported.

[0064] In the above-described embodiment, modified example 2, and modified example 3, gaps G1 to G5 are formed in the terminal-attached electric wire 10, the terminal-attached electric wire 210, and the terminal-attached electric wire 310. These gaps G1 to G5 may be formed around the entire periphery of the core wire 32, or may be formed only in part of the periphery of the core wire 32.

[0065] In the above-described modified example 3, the wire support portion is provided with two protrusions 328, and in the modified example 4, the wire support portion is provided with three protrusions 428, but the present invention is not limited to this. For example, the wire support portion may be provided with four or more protrusions. Even in such a structure, the core wire 32 is stably supported.

[0066] In the above-described embodiment and each modified example, the insulation displacement portion 24, 224 and the wire support portion 26, 126, 226, 326, 426 are not limited to being integral. A structure in which a ring-shaped wire support part is inserted inside the cylindrical insulation displacement portion may also be used. In this case, the wire support part may be fitted onto the core wire 32 and inserted into the cylindrical insulation displacement portion together with the core wire 32 and fixed in place. Alternatively, the wire support part may be inserted into the cylindrical insulation displacement portion and fixed as a single part before being fitted onto the core wire 32, and the core wire 32 may be supported inside the wire support part in this state. This wire support part may be made of plastic.

[0067] The configurations described in the above embodiments and modifications can be combined as appropriate as long as they are not mutually contradictory.

[0068] 10, 110, 210, 310, 410 Electric wire with terminal 20, 120, 220, 320, 420 Terminal 22, 322, 422 Cylindrical portion 22a, 322a, 422a Inner peripheral surface 24, 224 Pressure-welded portion 24a Inner peripheral surface 24i, 51i Arrow 26, 126, 226, 326, 426 Electric wire support portion 26a Inner peripheral surface 27, 127, 227 Bottom portion 28, 128 Inner peripheral portion 28a, 128a Inner peripheral surface 29 Mating connection portion 29a Hole 30 Electric wire 32 Core wire 32a Outer peripheral surface 32b End surface 50 Electromagnetic pressure welding device 51 Discharge coil 226a First electric wire support portion 226b Second wire support portion 327 Contact surface 328, 428 Projection 328a First projection 328b Second projection 428a First projection 428b Second projection 428c Third projection A Longitudinal direction C, C1, C2 Axial center F Arrow G1, G2, G3, G4, G5 Gap H Magnetic field R1 Outer diameter R2 Inner diameter R3 Inner diameter R4 Inner diameter

Claims

1. A terminal-equipped electric wire comprising: an electric wire including a core wire; and a terminal that is crimped onto the core wire, wherein the terminal includes a tubular portion, and the tubular portion has: a crimped portion that is crimped onto the core wire; and a wire support portion located adjacent to the crimped portion, wherein the wire support portion supports the core wire from outside in the circumferential direction of the core wire so as to maintain the position of the core wire relative to the crimped portion in a direction perpendicular to the longitudinal direction of the core wire.

2. An electric wire with terminal according to claim 1, wherein the electric wire support portion protrudes from the inner peripheral surface of the cylindrical portion toward the core wire.

3. An electric wire with terminal according to claim 1 or 2, wherein the inner peripheral surface of the electric wire support portion contacts the core wire over the entire circumference.

4. An electric wire with a terminal according to claim 1 or 2, wherein the electric wire support portion includes a plurality of protrusions that protrude from the inner peripheral surface of the cylindrical portion toward the inside of the cylindrical portion.

5. An electric wire with a terminal according to claim 1 or 2, wherein the electric wire support portion includes a first electric wire support portion and a second electric wire support portion, and the crimping processed portion is located between the first electric wire support portion and the second electric wire support portion.

6. An electric wire with terminal according to claim 1 or 2, wherein the core wire is a single core wire.

7. A terminal comprising a cylindrical portion, the cylindrical portion including: a crimped portion; and a wire support portion having an inner diameter smaller than the inner diameter of the crimped portion.

8. A terminal according to claim 7, wherein the axial center of the pressure-welding processed portion and the axial center of the electric wire support portion are formed coaxially.

9. A method for manufacturing an electric wire with a terminal for crimping a terminal and a core wire, comprising: preparing a terminal having a tubular portion, the tubular portion including a crimping portion and an electric wire support portion having an inner diameter smaller than the inner diameter of the crimping portion; supporting the core wire in the electric wire support portion; and electromagnetically crimping the crimping portion to the core wire while the core wire is supported by the electric wire support portion.

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