Terminals, wires with terminals

Abstract

To provide a terminal capable of satisfactorily welding a core wire of a covered electric wire, and a terminal-equipped wire connected to the terminal.SOLUTION: A terminal-equipped wire 1 includes a covered electric wire 2 and a terminal 3 connected to the terminal of the covered electric wire 2. The terminal 3 includes a bottom plate rear portion 38 on which the covered electric wire 2 is placed, a bottom plate front portion 34 that is flush with and continuous with the bottom plate rear portion 38, a pair of crimping pieces 39 that stand upwardly from both side edges of the bottom plate rear portion 38 and crimp the portion of the covered electric wire 2 where a sheath 22 is provided, and a welding portion 36 in which the exposed core wire 21 of the covered electric wire 2 is welded. The welding portion 36 is formed by punching out a portion between two slits formed in the bottom plate front portion 34 upward, and is located above the bottom plate rear portion 38.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a terminal to be connected to a covered electric wire, and to a terminal-attached electric wire in which a terminal is connected to a covered electric wire. [Background technology]

[0002] 12 and 13 is a known terminal to be connected to a coated electric wire (see Patent Document 1). This terminal 303 is obtained by pressing a metal plate or the like, and includes a mating portion 331 that mates with a mating terminal (not shown), a core wire crimping portion 333 that crimps the exposed core wire 21 of the coated electric wire 2, and a coating crimping portion 337 that crimps the portion of the coated electric wire 2 where the coating 22 is provided.

[0003] The core wire crimping portion 333 includes a bottom plate front portion 334 (this name is given when the fitting portion 331 side is the front and the coating crimping portion 337 side is the rear) and a pair of core wire crimping pieces 335 standing upright from both side edges of the bottom plate front portion 334. Serrations 332 are formed on the crimping pieces 335.

[0004] The covering crimping portion 337 includes a bottom plate rear portion 338 and a pair of covering crimping pieces 339 standing upright from both side edges of the bottom plate rear portion 338. The bottom plate rear portion 338 is continuous with the bottom plate front portion 334 and flush with each other. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-39901 Summary of the Invention [Problem to be solved by the invention]

[0006] The inventors of the present application have studied a terminal connection structure using the above-described terminal 303 in which the core wire 21 of the insulated electric wire 2 is welded to the bottom plate front portion 334 instead of being crimped by a pair of core wire crimping pieces 335.

[0007] However, as shown in Figure 13, when the coated wire 2 is set in the terminal 303, a gap g1 equal to the thickness of the coating 22 is created between the core wire 21 and the front part of the bottom plate 334, and it was found that when these are welded together, adhesion between the core wire 21 and the front part of the bottom plate 334 cannot be ensured, making it prone to poor welding.

[0008] Furthermore, as shown in Figure 14, even if the core wire 21 is bent so that it contacts the front part 334 of the bottom plate, gaps g2 and g3 are created in places, making it impossible to control the amount of gap, and it was found that this results in poor reproducibility.

[0009] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a terminal that can satisfactorily weld a core wire of a covered electric wire, and a terminal-attached electric wire to which the terminal is connected. [Means for solving the problem]

[0010] The present invention provides a wire clamping device comprising: a bottom plate on which a covered electric wire is placed; a pair of crimping pieces extending upward from both side edges of the bottom plate and bent toward the bottom plate to crimp the covered portion of the covered electric wire; and a welding portion to which an exposed core portion of the covered electric wire is welded, the welding portion being positioned above the bottom plate. The welded portion is a portion between two slits formed in the bottom plate, which is a flat surface protruding upward. The terminal is characterized by the above.

[0011] The present invention provides a terminal-equipped electric wire comprising a coated electric wire having an exposed core wire portion and the above-mentioned terminal, wherein the exposed core wire portion is welded to the welding portion, and the portion of the coated electric wire where the coating is provided is crimped by the crimping piece. [Effects of the Invention]

[0012] According to the present invention, the exposed core portion of the insulated electric wire can be brought into close contact with the welding portion, and therefore they can be welded well. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a perspective view of a terminal-attached electric wire in which a terminal according to a first embodiment of the present invention is connected to a coated electric wire. [Figure 2] 2 is a perspective view of the terminal of FIG. 1 in a state before being connected to a coated electric wire. [Figure 3] FIG. 3 is a side view of the terminal of FIG. 2. [Figure 4] FIG. 3 is a bottom view of the terminal of FIG. 2. [Figure 5] 5 is an explanatory view for explaining the dimensional relationship between the welded portion and the insulated electric wire in FIG. 4. [Figure 6] FIG. 2 is an explanatory view for explaining the dimensional relationship between the welded portion and the coated electric wire in FIG. [Figure 7] 5A and 5B are diagrams showing the welded portion of the terminal in FIG. 4, where (A) is a bottom view, (B) is a cross-sectional view taken along line BB in (A), and (C) is a cross-sectional view taken along line CC in (A). [Figure 8] 10A and 10B are explanatory diagrams for explaining the influence of the dimensional relationship between a welded portion and a coated electric wire. [Figure 9] 10A and 10B are explanatory diagrams for explaining the influence of the dimensional relationship between a welded portion and a coated electric wire. [Figure 10] 10A and 10B are explanatory diagrams for explaining the influence of the dimensional relationship between a welded portion and a coated electric wire. [Figure 11] 10A and 10B are diagrams showing a welded portion of a terminal according to a second embodiment of the present invention, in which (A) is a bottom view, (B) is a cross-sectional view taken along line DD in (A), and (C) is a cross-sectional view taken along line EE in (A). [Figure 12] FIG. 1 is a cross-sectional view of a conventional terminal. [Figure 13] 13 is a cross-sectional view showing a state in which an insulated electric wire is set in the terminal of FIG. 12. FIG. [Figure 14] 14 is a cross-sectional view showing a state in which the core wire of FIG. 13 has been bent so as to contact the front part of the bottom plate of the terminal. DETAILED DESCRIPTION OF THE INVENTION

[0014] A "terminal" and a "terminal-fitted wire" according to a first embodiment of the present invention will be described with reference to FIGS.

[0015] The electric wire with terminal 1 shown in FIG. 1 includes a covered electric wire 2 and a terminal 3 connected to an end of the covered electric wire 2.

[0016] The insulated electric wire 2 is composed of a core wire 21 made up of a plurality of conductive wires and an insulating coating 22 that covers the outer periphery of the core wire 21. The insulated electric wire 2 is a round electric wire having a circular cross section perpendicular to the longitudinal direction. A part of the coating 22 is removed at the end of the insulated electric wire 2 to expose the core wire 21 (this part corresponds to the "exposed core wire part").

[0017] The terminal 3 is obtained by subjecting a metal plate to press working or the like. As shown in Figures 2 to 4, the terminal 3 includes a fitting portion 31 that fits with a mating terminal (not shown), a wire joining portion 33 that joins with the exposed core wire 21 (exposed core portion) of the insulated electric wire 2, and a covering crimping portion 37 that crimps the portion of the insulated electric wire 2 where the covering 22 is provided.

[0018] The fitting portion 31 is formed in a rectangular cylindrical shape, and receives a rod-shaped or plate-shaped mating terminal therein.

[0019] The electric wire joint portion 33 includes a bottom plate front portion 34, a welding portion 36 to which the exposed core wire 21 of the coated electric wire 2 is welded, and a pair of side plates 35.

[0020] The welded portion 36 is a portion that protrudes upward between two parallel slits formed in the bottom plate front portion 34, and is formed by stamping. As shown in Fig. 7, the welded portion 36 is a flat surface parallel to the bottom plate front portion 34, and is formed in a rectangular shape extending in the longitudinal direction of the terminal 3 when viewed from above.

[0021] The pair of side plates 35 are erected upward from both side edges of the bottom plate front portion 34, face each other, and have a welding portion 36 positioned therebetween. The exposed core 21 of the insulated electric wire 2 is positioned between the pair of side plates 35, and this core 21 is welded to the welding portion 36. In addition, in the electric wire with terminal 1 of this example, the core 21 is laser-welded to the welding portion 36.

[0022] The cover crimping portion 37 includes a bottom plate rear portion 38 and a pair of crimping pieces 39 standing upward from both side edges of the bottom plate rear portion 38 .

[0023] The bottom plate rear portion 38 is flush with and continuous with the bottom plate front portion 34. Therefore, the welded portion 36 is located higher than the bottom plate rear portion 38. The bottom plate front portion 34 and the bottom plate rear portion 38 correspond to the "bottom plate" in the claims.

[0024] 1 and 6, the portion of the insulated electric wire 2 where the coating 22 is provided is placed on the rear portion 38 of the bottom plate. The pair of crimping pieces 39 are bent toward the rear portion 38 of the bottom plate to crimp the portion of the insulated electric wire 2 where the coating 22 is provided.

[0025] Furthermore, since the welding portion 36 is located above the rear portion 38 of the bottom plate, when the portion of the insulated electric wire 2 provided with the coating 22 is placed on the rear portion 38 of the bottom plate, the exposed core wire 21 is placed on the welding portion 36 (the height of the welding portion 36 is set so that this happens).

[0026] This type of terminal 3 is manufactured by modifying a part of an existing crimp terminal, by eliminating the crimp blade on the side plate 35, forming two parallel slits in the front part 34 of the bottom plate, and hammering the part between these slits upward by a predetermined distance to form a welded part 36.

[0027] For convenience, the terminal 3 is described as having the mating portion 31 side as the front, the sheath crimping portion 37 side as the rear, the bottom plate front portion 34 and the bottom plate rear portion 38 side as the bottom, and the tip side of the side plate 35 away from the bottom plate front portion 34 as the top. These front-to-back and up-down directions do not have to match the actual directions.

[0028] Next, the dimensional relationship between the welded portion 36 and the insulated electric wire 2 in the electric wire with terminal 1 will be described. In the electric wire with terminal 1, it is preferable that the height dimension h of the welded portion 36 from the bottom plate front portion 34 shown in Fig. 6 is equal to or less than the thickness t of the insulated electric wire 22, and that the difference between them (th) is within 10% of the outer diameter d of the core wire 21 of the insulated electric wire 2. In other words, it is preferable that the following formula 1 is satisfied. (Formula 1) Coating thickness t - core wire outer diameter d × 0.1 ≦ height dimension h of welded portion 36 ≦ coating thickness t

[0029] The basis for the above formula 1 is that if the height dimension h of the welded portion 36 exceeds the coating thickness t, the core wire 21 will rise, as shown in FIG. 10, and a gap will be created between the welded portion 36 and the core wire 21. Therefore, as mentioned above, it is preferable that the height dimension h of the welded portion 36 be equal to or less than the coating thickness t. Furthermore, if the gap between the welded portion 36 and the core wire 21 is larger than 10% of the core wire outer diameter d, poor welding is likely to occur in laser welding. Therefore, as mentioned above, it is preferable that the difference between the coating thickness t and the height dimension h of the welded portion 36 be within 10% of the core wire outer diameter d.

[0030] In the electric wire with terminal 1, the width w of the welded portion 36 shown in Fig. 5 is preferably 1.1 times or more the outer diameter d of the core wire 21 of the insulated electric wire 2. That is, it is preferable that the following formula 2 is satisfied. (Formula 2) Width w of welded portion 36 ≧ Core wire outer diameter d × 1.1

[0031] The basis for the above formula 2 is that, as shown in Fig. 8, if the width w of the welded portion 36 is equal to the outer diameter d of the core wire, the molten core wire 21 will flow out onto the back surface of the terminal through the slits on both sides of the welded portion 36. Therefore, as shown in Fig. 9, as a range in which the molten core wire 21 does not flow out onto the back surface of the terminal, it is preferable that the width w of the welded portion 36 is 1.1 times or more the outer diameter d of the core wire, as described above.

[0032] In the electric wire with terminal 1, the length l of the welded portion 36 shown in Fig. 5 is preferably 1.4 times or more the outer diameter d of the core wire 21 of the insulated electric wire 2. That is, it is preferable that the following formula 3 is satisfied. (Equation 3) Length l of welded portion 36 ≧ Core wire outer diameter d × 1.4

[0033] The basis for the above formula 3 is that the shear strength is generally 60% (at least) of the tensile strength of the material, so in order to ensure the strength of the welded portion is equivalent to the tensile strength of the electric wire, as described above, it is preferable that the length l of the welded portion 36 be 1.4 times or more the outer diameter d of the core wire.

[0034] In the electric wire with terminal 1 having the above configuration, the interface between the core wire 21 of the insulated electric wire 2 and the welded portion 36 of the terminal 3 can be brought into close contact with each other on a surface basis, which results in fusion and joining with good reproducibility during welding. That is, by providing the welded portion 36 on the terminal 3, the adhesion between the core wire 21 and the terminal 3 can be improved, which in turn improves the welding quality (strength of the welded portion, conductivity).

[0035] A "terminal" according to a second embodiment of the present invention will be described with reference to Fig. 11. In Fig. 11, the same components as those in the first embodiment are given the same reference numerals and description thereof will be omitted.

[0036] 11A and 11B are diagrams showing a welded portion 136 of a terminal 103 according to a second embodiment of the present invention, in which (A) is a bottom view, (B) is a cross-sectional view taken along line DD in (A), and (C) is a cross-sectional view taken along line EE in (A).

[0037] In the first embodiment, the welded portion 36 was formed by hammering out the portion between two slits formed in the bottom plate front portion 34, but in the present embodiment shown in Fig. 11, no slit is formed, and the welded portion 136 protrudes upward by simply hammering out a portion of the bottom plate front portion 34. The terminal 103 has the same configuration as the terminal 3 of the first embodiment, except for the welded portion 136.

[0038] The welded portion 136 of this example has the same effect as the welded portion 36 of the first embodiment. That is, by providing the welded portion 136 on the terminal 103, it is possible to improve the adhesion between the core wire of the insulated electric wire and the terminal 103, thereby improving the welding quality (welded portion strength, electrical conductivity).

[0039] The above-described embodiment merely shows a typical form of the present invention, and the present invention is not limited to this embodiment. In other words, the present invention can be implemented with various modifications within the scope of the gist of the present invention. As long as such modifications still include the configuration of the present invention, they are of course included in the scope of the present invention. [Explanation of symbols]

[0040] 1 Wire with terminal 2. Insulated wire 3,103 terminals 21 Core Wire 22 Covering 31 Fitting part 33 Wire joint 34 Front part of bottom plate (bottom plate) 35 Side panel 36,136 Welds 37 Coverage crimping part 38 Bottom plate rear part (bottom plate) 39 Crimping piece

Claims

1. The insulated electric wire is placed on a bottom plate, a pair of crimping pieces extending upward from both side edges of the bottom plate and bent toward the bottom plate to crimp the portion of the insulated electric wire where the insulated electric wire is provided, and a welding portion to which an exposed core portion of the insulated electric wire is welded, The welded portion is located above the bottom plate, The welded portion is a portion between two slits formed in the bottom plate, which is made of a flat surface protruding upward. A terminal characterized by:

2. The base plate has a pair of side plates that stand upright from both side edges of the base plate, face each other, and have the welded portion positioned between them.

2. The terminal according to claim 1 .

3. A coated electric wire having an exposed core portion and the terminal according to claim 1 or 2, the exposed core wire portion is welded to the welding portion, The portion of the insulated wire where the coating is provided is crimped by the pair of crimping pieces. A terminal-attached electric wire characterized by:

4. The height dimension of the welded portion from the bottom plate is equal to or less than the thickness of the coating of the insulated electric wire, and the difference between the height and the thickness is within 10% of the outer diameter of the core wire of the insulated electric wire. The electric wire with terminal according to claim 3 .

5. The width of the welded portion is 1.1 times or more the outer diameter of the core wire of the insulated electric wire. The electric wire with terminal according to claim 3 .

6. The length of the welded portion is 1.4 times or more the outer diameter of the core wire of the insulated electric wire. The electric wire with terminal according to claim 3 .

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