Wiring member with terminal and method for manufacturing wiring member with terminal

Abstract

The purpose of the present invention is to enable a better connection between a single-core wire and a terminal. This wiring member with a terminal comprises a terminal including a crimping part, a single-core wire to which the crimping part is crimped, and a weld bead. The weld bead follows along the boundary between the crimping part and the single-core wire.

Description

Terminal-attached wiring member and method for manufacturing the terminal-attached wiring member

[0001] The present disclosure relates to a terminal-attached wiring member and a method for manufacturing the terminal-attached wiring member.

[0002] Patent Document 1 discloses a crimp terminal including a crimping portion that is crimped to an electric wire, and a sealing portion that is formed at one end of the crimping portion and that seals the electric wire that is crimped to the crimping portion. Patent Document 1 discloses that the sealing is achieved by welding.

[0003] International Publication No. 2016 / 027900

[0004] In this regard, it is desirable to be able to perform a better connection between the single-core wire and the terminal.

[0005] Therefore, an object of the present disclosure is to enable better connection between a single-core wire and a terminal.

[0006] The terminal-attached wiring member of the present disclosure is a terminal-attached wiring member comprising a terminal including a crimping portion, a single-core wire to which the crimping portion is crimped, and a weld bead along the boundary between the crimping portion and the single-core wire.

[0007] In addition, the manufacturing method of a terminal-attached wiring member disclosed herein is a manufacturing method of a terminal-attached wiring member, which includes preparing a terminal including a crimping portion and a single-core wire, crimping the crimping portion to the single-core wire, and laser welding the crimping portion and the single-core wire together.

[0008] According to the present disclosure, a single core wire and a terminal can be connected more satisfactorily.

[0009] FIG. 1 is a side view showing a terminal-attached wiring member according to an embodiment. FIG. 2 is a front view showing the terminal-attached wiring member. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. FIG. 4 is an enlarged view of part A in FIG. 3. FIG. 5 is an explanatory diagram showing a method for manufacturing a terminal-attached wiring member. FIG. 6 is an explanatory diagram showing a method for manufacturing a terminal-attached wiring member. FIG. 7 is an explanatory diagram showing a method for manufacturing a terminal-attached wiring member.

[0010] [Description of Embodiments of the Present Disclosure] First, embodiments of the present disclosure will be listed and described.

[0011] The terminal-equipped wiring member of the present disclosure is as follows.

[0012] (1) A terminal-attached wiring member including a terminal including a crimping portion, a single-core wire to which the crimping portion is crimped, and a weld bead along the boundary between the crimping portion and the single-core wire.

[0013] According to the present disclosure, the crimping portion is crimped to the single-core wire, and further, the crimping portion and the single-core wire are welded together with a weld bead. This allows the terminal and the single-core wire to be connected stably with low resistance, thereby improving the connection between the single-core wire and the terminal. Furthermore, the tensile strength of the single-core wire relative to the terminal is ensured by the crimping of the crimping portion to the single-core wire.

[0014] (2) In the terminal-attached wiring member of (1), the weld bead may be a portion where the crimped portion and the single-core wire are laser-welded along the boundary therebetween.

[0015] This limits the effect of welding and allows for better connection between the single-core wire and the terminal.

[0016] (3) In the terminal-attached wiring member of (1) or (2), a ring-shaped boundary between the crimping portion and the single-core wire may be present at the tip side of the single-core wire, and the weld bead may extend along at least a portion of the boundary.

[0017] This allows the weld bead to extend along at least a portion of the front boundary, making it easy to form the weld bead by welding from the front end of the single-core wire.

[0018] (4) In any one of the terminal-attached wiring members (1) to (3), the outer surface of the crimping portion may have a continuous shape extending from the axial center of the crimping portion toward the tip of the single-core wire.

[0019] This makes it easier to bring the crimping portion and the single-core wire into close contact with each other at the tip end of the single-core wire, thereby enabling good welding of the crimping portion and the single-core wire at the tip end of the single-core wire.

[0020] (5) In the terminal-equipped wiring member according to any one of (1) to (4), the terminal may be made of copper or a copper alloy, and the single-core wire may be made of aluminum or an aluminum alloy.

[0021] Using a single-core wire made of aluminum or an aluminum alloy allows for a lighter weight and thinner diameter of the terminal-attached wiring member. Furthermore, when using a single-core wire made of aluminum or an aluminum alloy, the single-core wire is less likely to deform during crimping, and the strong oxide film on the surface of the single-core wire may not be destroyed. Therefore, crimping alone may not be enough to stably connect the terminal and the single-core wire with low resistance. Therefore, welding the crimped portion and the single-core wire destroys the oxide film on the surface of the single-core wire, resulting in a stable, low-resistance connection between the crimped portion and the single-core wire.

[0022] (6) In the terminal-attached wiring member according to any one of (1) to (5), the crimped portion may be a closed barrel that is crimped so that the outer periphery has a polygonal prism-like outer periphery.

[0023] If the crimping portion is a closed barrel that is crimped so that the outer periphery has a polygonal prism-like outer periphery, the single-core wire can be easily compressed within the closed barrel, and therefore the crimping portion can be easily firmly crimped and fixed to the single-core wire.

[0024] The method for manufacturing a terminal-equipped wiring member according to the present disclosure is as follows.

[0025] (7) A method for manufacturing a terminal-attached wiring member, comprising the steps of preparing a terminal including a crimping portion and a single-core wire, crimping the crimping portion to the single-core wire, and laser welding the crimping portion and the single-core wire together.

[0026] According to the present disclosure, the crimping portion is crimped to the single-core wire, and then the crimping portion and the single-core wire are laser welded together. By adopting a laser welding structure in addition to a crimping structure, the terminal and the single-core wire can be connected stably with low resistance, and the connection between the single-core wire and the terminal can be more favorable. Furthermore, the tensile strength of the single-core wire relative to the terminal is ensured by the crimping of the crimping portion to the single-core wire.

[0027] [Details of the Embodiments of the Present Disclosure] Specific examples of the terminal-attached wiring member and the manufacturing method of the terminal-attached wiring member 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 of the claims.

[0028] [Embodiment] A terminal-attached wiring member and a method for manufacturing a terminal-attached wiring member according to an embodiment will now be described. Fig. 1 is a side view showing a terminal-attached wiring member 10. Fig. 2 is a front view showing the terminal-attached wiring member 10. Fig. 3 is a cross-sectional view taken along line III-III in Fig. 2. Fig. 4 is an enlarged view of part A in Fig. 3.

[0029] The terminal-attached wiring member 10 includes a terminal 20 , a single-core wire 30 , and a weld bead 40 .

[0030] The terminal 20 is a component made of copper or a copper alloy. The terminal 20 is formed, for example, by press-forming a copper or copper alloy plate material. The terminal may also be formed by machining a copper or copper alloy base material.

[0031] If the terminal 20 is made of copper or a copper alloy, it has better spring properties than aluminum or an aluminum alloy, and is therefore suitable for crimping connection. It is not essential that the terminal 20 be made of copper or a copper alloy, and the terminal 20 may be made of, for example, aluminum or an aluminum alloy.

[0032] The terminal 20 is a component that connects the single-core wire 30 to a component to which it is to be connected. In this embodiment, the terminal 20 has a crimping portion 22 and a mating connection portion 24. The mating connection portion 24 is linearly connected to the tip side of the crimping portion 22. The portion between the crimping portion 22 and the mating connection portion 24 may be curved.

[0033] The crimping portion 22 is a portion that is crimped to the single-core wire 30. In this embodiment, the crimping portion 22 is a so-called closed barrel crimping portion. A closed barrel refers to a crimping portion that is continuous and cylindrical before and after crimping. The closed barrel may be a portion that is initially processed into a cylindrical shape, or may be a configuration in which a plate-like portion is deformed and joined to form a cylindrical shape. The joining to form the cylindrical shape may be performed by, for example, welding.

[0034] For example, it is assumed that the crimping portion 22 is formed in a cylindrical shape before crimping, and that with the single-core wire 30 disposed therein, the crimping portion 22 is compressively deformed to reduce the internal space, thereby holding the single-core wire 30 within the crimping portion 22. The outer peripheral shape of the crimping portion 22 crimped to the single-core wire 30 may be a polygonal prism outer peripheral surface shape (for example, a hexagonal prism outer peripheral surface shape (see FIG. 3 )), or a flat shape such as an ellipse.

[0035] It should be noted that even if the crimped portion 22 is crimped to have a polygonal prism-like outer peripheral surface shape, it is conceivable that the inner peripheral surface shape of the crimped portion 22 is closer to a circle than the outer peripheral surface shape.

[0036] The crimping portion 22 does not need to be formed as a closed barrel. For example, before crimping, the crimping portion may be a so-called open barrel or F-crimp type crimping portion having a pair of crimping pieces rising from both sides of the bottom portion. In this case, with the single-core wire placed on the bottom portion and between the pair of crimping pieces, the pair of crimping pieces may be compressively deformed toward the single-core wire, so that the single-core wire is held between the bottom portion and the pair of crimping pieces.

[0037] The portion of the outer circumferential surface of the crimping portion 22 extending from the axial center of the crimping portion 22 toward the tip end of the single-core wire 30 may have a continuous shape. The outer circumferential shape of the crimped crimping portion 22 may be formed, for example, by transferring the shape of a mold surface that crimps the crimping portion 22. Alternatively, the crimping portion 22 may be formed by crimping a cylindrical portion having the same thickness in the circumferential direction. For this reason, it is assumed that the portion of the inner circumferential surface of the crimping portion 22 extending from the axial center of the crimping portion 22 toward the tip end of the single-core wire 30 also has a continuous shape.

[0038] In this embodiment, the outer peripheral surface of the crimping portion 22 has a shape that is continuous with the same shape over the entire axial direction of the crimping portion 22. Therefore, it is assumed that the inner peripheral surface of the crimping portion 22 has a shape that is continuous with the same shape over the entire axial direction of the crimping portion 22.

[0039] For example, the crimping portion of a crimp terminal that is crimped to a twisted wire may have a tapered portion called a bell mouth formed at the axial end. However, the main crimping portion 22 does not have such a bell mouth.

[0040] The mating connection portion 24 is a portion that is connected to a component to which the single-core wire 30 is connected. In this embodiment, the mating connection portion 24 is a plate-like portion having a hole. For example, the mating connection portion 24 may be screwed to the component to which it is connected. The component to which it is connected may be a terminal of an electrical device, a metal housing, a metal body of a vehicle, or the like. The mating connection portion 24 may be a pin- or rod-like portion that is inserted into a cylindrical portion of the mating terminal, or a cylindrical portion into which the mating terminal is inserted.

[0041] The single core wire 30 is made of aluminum or an aluminum alloy. A single core wire is a portion of aluminum or an aluminum alloy that forms a single linear portion without being divided. Therefore, a single core wire is not a stranded wire or a stranded wire in which multiple core wires are gathered together. Note that the single core wire does not have to be made of aluminum or an aluminum alloy, and may be made of, for example, copper or a copper alloy.

[0042] Forming the wiring conductor of the terminal-attached wiring member 10 from aluminum or an aluminum alloy enables a reduction in weight of the terminal-attached wiring member 10. Furthermore, forming the wiring conductor of the terminal-attached wiring member 10 as a single-core wire enables a reduction in diameter of the terminal-attached wiring member 10.

[0043] The shape of the cross section of the single core wire 30 is not particularly limited and may be circular, elliptical, or polygonal. In this embodiment, the cross section of the single core wire 30 is circular. The cross section of the single core wire 30 is a cross section in a direction perpendicular to the longitudinal direction of the single core wire 30.

[0044] At least the end of the single core wire 30 is exposed. The crimping portion 22 is crimped to the exposed end of the single core wire 30. The end face of the single core wire 30 faces the mating connection portion 24. Therefore, when the terminal-attached wiring member 10 is observed from the tip side of the terminal-attached wiring member 10 (i.e., the mating connection portion 24 side), the end face of the single core wire 30 is surrounded by the end face of the crimping portion 22 except for the area where the mating connection portion 24 is present.

[0045] In the axial direction of the single core wire 30, the end face of the single core wire 30 may be located flush with the end face of the crimping portion 22, or may be located at a position different from the end face of the crimping portion 22. As will be described later, in the axial direction of the single core wire 30, the end face of the single core wire 30 is preferably located flush with the end face of the crimping portion 22 or recessed relative to the end face of the crimping portion 22. The case where the end face of the single core wire 30 is located flush with the end face of the crimping portion 22 includes a case where the end face of the single core wire 30 is manufactured so as to be located flush with the end face of the crimping portion 22, but is not flush due to factors such as manufacturing error, and includes a case where the end face of the single core wire 30 protrudes or recesses relative to the end face of the crimping portion 22 within a range of 0.5 mm, for example.

[0046] At least a portion of the single core wire, for example, a middle portion in the longitudinal direction of the single core wire 30, may be covered with a resin or the like.

[0047] The weld bead 40 is a welded portion formed at the welded location between the crimped portion 22 and the single-core wire 30. The weld bead 40 is formed along a boundary 42 between the crimped portion 22 and the single-core wire 30.

[0048] More specifically, an annular tip boundary 42 between the crimped portion 22 and the single core wire 30 exists on the tip side of the single core wire 30. The tip boundary 42 is an annular contact point between the inner circumferential surface of the crimped portion 22 and the outer circumferential surface of the single core wire 30. Before welding, the tip boundary 42 can be observed from the outside. After welding, the tip boundary 42 is the portion inside the weld bead 40 where the crimped portion 22 and the single core wire 30 are in contact.

[0049] The weld bead 40 is formed along at least a portion of the tip boundary 42. In this embodiment, the weld bead 40 is formed along the entire circumferential direction of the annular tip boundary 42. The weld bead may be formed along a portion of the circumferential direction of the annular tip boundary. The weld bead may be formed intermittently along the circumferential direction of the annular tip boundary. In this embodiment, the weld bead 40 is formed annularly along the entire tip boundary 42.

[0050] The weld bead 40 is the portion where the crimped portion 22 and the single-core wire 30 are welded, and is therefore a portion where the copper or copper alloy forming the crimped portion 22 and the aluminum or aluminum alloy forming the single-core wire 30 are melted together. The degree of melting between the copper or copper alloy and the aluminum or aluminum alloy may not be uniform in the weld bead 40. Furthermore, the boundary between the weld bead 40 and the crimped portion 22 or the boundary between the weld bead 40 and the single-core wire 30 may be clearly distinguishable in some cases, or may not be clearly distinguishable in other cases due to a gradual transition in the components.

[0051] The weld bead 40 is a portion where the base material forming the crimped portion 22 and the base material forming the single core wire 30 melt together and solidify while remaining integrally continuous with the crimped portion 22 and the single core wire 30. The weld bead 40 has an irregular surface relative to the surfaces of the crimped portion 22 and the single core wire 30, and may, for example, have a surface that protrudes relative to the surfaces of the crimped portion 22 and the single core wire 30.

[0052] When the crimping portion 22 and the single-core wire 30 are welded at the boundary 42, the oxide film formed on the surface of the single-core wire 30 is destroyed. Therefore, the crimping portion 22 and the single-core wire 30 are connected with low resistance by the weld bead 40.

[0053] The weld bead 40 may be, for example, a portion where the crimped portion 22 and the single-core wire 30 are laser-welded along a boundary 42 therebetween. Laser welding refers to irradiating two welding locations with laser light to melt and join the two welding locations. The weld bead 40 may also be a portion welded by a welding method other than laser welding.

[0054] For example, by irradiating the laser light along the annular tip-side boundary 42, the crimped portion 22 and the single-core wire 30 melt together at the tip-side boundary 42 to form the weld bead 40. In this case, it is considered that the crimped portion 22 and the single-core wire 30 are not welded to each other at the inner side of the crimped portion 22, for example, at the middle part of the crimped portion 22 in the longitudinal direction.

[0055] The laser light may be applied simply along a circular path along the annular leading edge boundary 42. The laser light may be applied along a path that progresses in a zigzag pattern while following the leading edge boundary 42. This allows the width of the weld bead 40 to be increased.

[0056] An example of a method for manufacturing the terminal-equipped wiring member 10 will be described.

[0057] As shown in Figure 5, a terminal 20B before crimping and a single-core wire are prepared. The inner space of the crimping portion 22B of the terminal 20B is larger than the inner space of the crimping portion 22 after crimping, and is, for example, a cylindrical space. This allows the end of the single-core wire 30 to be easily inserted into the crimping portion 22B. Then, a pair of crimping dies 50, 52 compressively deform the crimping portion 22B to crimp the crimping portion 22 to the single-core wire 30.

[0058] For example, as shown by the two-dot chain line in Fig. 6, the crimping portion 22B before crimping has a cylindrical shape. As shown by the two-dot chain line in Fig. 6, the single-core wire 30 is thin enough to be easily inserted into the crimping portion 22B. Therefore, the single-core wire 30 can be easily inserted into the crimping portion 22B.

[0059] The die surfaces of the pair of crimping dies 50, 52 are formed into a shape corresponding to the outer peripheral shape of the crimped portion 22 after crimping. For example, the die surface of each of the pair of crimping dies 50, 52 is formed into a shape obtained by dividing the outer peripheral shape of a polygonal prism into two. By moving one or both of the pair of crimping dies 50, 52 in a direction toward each other, the crimped portion 22 is crimped to the single-core wire 30 between the pair of crimping dies 50, 52. The shape of the die surfaces of the pair of crimping dies 50, 52 is transferred to the crimped crimped portion 22. For example, the outer peripheral surface shape of the crimped portion 22 is formed into a polygonal prism outer peripheral surface shape. The internal space of the crimped portion 22 is smaller than the internal space of the crimped portion 22B, and the end of the single-core wire 30 is crimped and held within the crimped portion 22.

[0060] It is thought that an oxide film is formed on the surface of the single core wire 30 made of aluminum or an aluminum alloy. When the crimping portion 22 is crimped, the crimping portion 22 is pressed against the surface of the single core wire 30 while deforming the surface of the single core wire 30, but there is a possibility that an oxide film remains on the surface of the single core wire 30.

[0061] 7, the laser light is irradiated along the boundary 42 between the single core wire 30 and the crimped portion 22. Preferably, the laser light is irradiated along the entire boundary 42 on the tip side.

[0062] For the tip-side boundary 42, a laser beam irradiation device 60 is disposed on the tip side of the single-core wire 30, and laser beam 60L can be irradiated from the laser beam irradiation device 60 toward the tip-side boundary 42. This facilitates laser welding of the tip-side boundary 42. Note that, in the portion where the mating connection portion 24 exists, the laser beam 60L may be irradiated obliquely toward the boundary between the crimping portion 22 and the mating connection portion 24.

[0063] To ensure good welding, the end face of the single-core wire 30 may be flush with the end face of the crimped portion 22 or may protrude beyond the end face of the crimped portion 22. If the end face of the single-core wire 30 coincides with the end face of the crimped portion 22, good welding can be easily performed by irradiating both end faces with laser light 60L at the boundary between them. Furthermore, aluminum or aluminum alloys melt more easily than copper or copper alloys. Therefore, even if the end face of the single-core wire 30 protrudes beyond the end face of the crimped portion 22, by melting the protruding portion of the single-core wire 30, good welding can be easily performed by irradiating both end faces with laser light 60L at the boundary between them.

[0064] By welding the crimping portion 22 and the single core wire 30 together, the oxide film on the surface of the single core wire 30 is destroyed, and the crimping portion 22 and the single core wire 30 are connected with low resistance.

[0065] According to the wiring member 10 with terminal and the manufacturing method for the wiring member 10 configured as described above, in addition to the structure in which the crimping portion 22 is crimped to the single core wire 30, the crimping portion 22 and the single core wire 30 are welded together by the weld bead 40. The oxide film is destroyed at the welded portion between the crimping portion 22 and the single core wire 30. This allows the terminal 20 and the single core wire 30 to be connected stably with low resistance, resulting in a better connection between the single core wire 30 and the terminal 20. Furthermore, the tensile strength of the single core wire 30 relative to the terminal 20 is ensured by the crimping of the crimping portion 22 to the single core wire 30.

[0066] Furthermore, if the weld bead 40 is a portion that is laser welded along the boundary 42, the effects of welding can be limited, resulting in a better connection between the single-core wire 30 and the terminal 20. In other words, if the entire crimped portion 22 is heated to a high temperature, there is a possibility that stress in the crimped portion 22 will be relaxed. With laser welding, it is sufficient to irradiate a laser beam onto the boundary 42, particularly a limited area along the boundary 42 on the tip side. Furthermore, the heating time for welding can be shortened. Therefore, thermal effects are less likely to extend to the longitudinal intermediate portion and the base end portion of the crimped portion 22, and stress relaxation in the crimped portion 22 is less likely to occur. This makes it easier for the crimped portion 22 to maintain its force in holding the single-core wire 30.

[0067] Furthermore, since there is no need to apply pressure during welding, the shape of the crimped portion 22 is likely to be maintained in its initial state at the time of crimping, which makes it easier to ensure the desired crimp holding force.

[0068] Furthermore, since it is not necessary to pinch the crimped portion with a member for applying welding energy, the welding work is facilitated.

[0069] Furthermore, weld bead 40 extends along at least a portion of tip-side boundary 42. Therefore, weld bead 40 can be easily formed by welding from the tip side of single-core wire 30.

[0070] The welding may be performed on the base end side of the crimping portion 22, that is, on the side from which the single-core wire 30 extends.

[0071] Furthermore, the portion of the outer circumferential surface of the crimping portion 22 extending from the axial center of the crimping portion 22 toward the tip end of the single-core wire has a continuous shape, which makes it easy to bring the crimping portion 22 and the single-core wire 30 into close contact with each other at the tip end of the crimping portion 22. This allows the crimping portion 22 and the single-core wire 30 to be well welded at the tip end of the single-core wire 30.

[0072] Furthermore, by using a single-core wire 30 made of aluminum or an aluminum alloy, it is possible to reduce the weight and diameter of the terminal-attached wiring member 10. However, when a single-core wire 30 made of aluminum or an aluminum alloy is used, the single-core wire 30 is less likely to deform during crimping, and a strong oxide film may be formed on the surface of the single-core wire 30. For this reason, crimping alone may not be enough to stably connect the terminal 20 and the single-core wire 30 with low resistance. Therefore, by welding the crimping portion 22 and the single-core wire 30, the oxide film on the surface of the single-core wire 30 is destroyed, and the crimping portion 22 and the single-core wire 30 are stably connected with low resistance.

[0073] Furthermore, if the crimping portion 22 is a closed barrel that is crimped so that its outer periphery has a polygonal prism-like outer periphery, the single-core wire 30 can be easily compressed within the closed barrel. Therefore, the crimping portion 22 can be easily and firmly crimped and fixed to the single-core wire 30.

[0074] The configurations described in the above embodiment and modifications can be combined as appropriate as long as they are not mutually inconsistent.

[0075] REFERENCE SIGNS LIST 10 Terminal-attached wiring member 20, 20B Terminal 22, 22B Crimped portion 24 Mating connection portion 30 Single-core wire 40 Weld bead 42 Tip-side boundary 50, 52 Crimping die 60 Laser light irradiation device

Claims

1. A terminal wiring member comprising a terminal including a crimping portion, a single-core wire to which the crimping portion is crimped, and a welding bead along a boundary between the crimping portion and the single-core wire.

2. The terminal wiring member according to claim 1, wherein the welding bead is a portion where the crimping portion and the single-core wire are laser welded along their boundary.

3. The terminal wiring member according to claim 1 or 2, wherein an annular tip-side boundary between the crimping portion and the single-core wire exists on the tip side of the single-core wire, and the welding bead is along at least a part of the tip-side boundary.

4. The terminal wiring member according to claim 1 or 2, wherein a portion of the outer peripheral surface of the crimping portion from the axial center portion of the crimping portion toward the tip side of the single-core wire has a shape in which the same shape is continuous.

5. The terminal wiring member according to claim 1 or 2, wherein the terminal is made of copper or a copper alloy, and the single-core wire is made of aluminum or an aluminum alloy.

6. The terminal wiring member according to claim 1 or 2, wherein the crimping portion is a closed barrel crimped so that the outer peripheral shape forms a polygonal prism outer peripheral surface shape.

7. A method for manufacturing a terminal wiring member, comprising preparing a terminal including a crimping portion and a single-core wire, crimping the crimping portion to the single-core wire, and laser welding the crimping portion and the single-core wire.

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