Conductor crimping method for crimp connection terminal

Abstract

To firmly crimp and fix a conductor of an electric wire by a conductor crimping portion.SOLUTION: A crimp connection terminal in which a pair of conductor crimping pieces 3a, 3b rise from a bottom portion 3c, folded-back pieces 3e bent inward by folded portions 3d are provided at upper ends thereof, and a gap 3f is formed on an inner side of the folded-back pieces 3e is used. In order to crimp-connect a conductor 5, in a first step, the conductor 5 is placed on the bottom portion 3c of a conductor crimping portion 3. In a second step, using a crimping and fixing device, the conductor crimping portion 3 is pressed from left and right directions to be deformed so as to wrap the conductor 5, the folded-back pieces 3e are brought close to each other and brought into close contact with each other, and a closed space S is formed between the conductor 5 and the conductor crimping pieces. In a third step, the folded-back pieces 3e are pressed from both sides to crush the gap 3f and reduce the closed space S. In a fourth step, the folded portions 3d are pressed downward and the bottom portion 3c is pressed upward to plastically deform the conductor 5, the conductor crimping portion 3 is brought into close contact with the conductor 5 by plastic deformation, and the closed space S is substantially closed.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a conductor crimping method that can be suitably applied to a small crimp connection terminal that is fitted inside a connector housing, for example, and that mates with a crimp connection terminal of a mating connector. [Background technology]

[0002] As electrical components become smaller, lighter, and more integrated, smaller connection terminals are required for connecting circuits. For this reason, various crimping methods for crimping connection terminals that are compatible with thinned solid conductors of electrical wires are known. Summary of the Invention [Problem to be solved by the invention]

[0003] When fixing a crimped connection terminal made of a metal plate to a conductor, it is essential to ensure mechanical strength and electrical conductivity.To achieve this, it is desirable to crimp the terminal to a solid-wire conductor by firmly adhering it to the surrounding area with the conductor crimping part.

[0004] 8 is a cross-sectional view showing a schematic diagram of the crimping and fixing structure for a conductor obtained in this example. In the conductor crimping pieces B and C of the crimp connection terminal that surround the conductor A of a solid wire of an electric cable, the tips of the conductor crimping pieces B and C located above the conductor A are folded inward and stacked in two layers on each side above the conductor A, for a total of four layers. When the conductor crimping pieces B and C are plastically deformed in this state to form a terminal crimping structure that crimps the conductor A from the periphery, a strong fixing force to the conductor A is obtained and good electrical performance is obtained.

[0005] However, when using a conventional crimp connection terminal in which conductor crimping pieces B and C are simply raised in a V-shape as shown in Figure 9, it is extremely difficult to obtain the terminal crimp structure shown in Figure 8 by bending the conductor crimping pieces B and C during crimping, and it is almost impossible, especially in the case of small crimp connection terminals.

[0006] The object of the present invention is to solve the above-mentioned problems and to provide a conductor crimping method for a crimp connection terminal that uses a crimp connection terminal that is equipped with a folded piece with a gap at the tip of the conductor crimping piece, and that can reliably crimp the conductor using a conductor crimping device, thereby achieving strong fixing force and conductivity. [Means for solving the problem]

[0007] To achieve the above object, the present invention provides a conductor crimping method for a crimp connection terminal, which includes a crimping terminal having a conductor crimping portion having a pair of conductor crimping pieces that rise from a bottom in a V-shape on both sides, and each tip of the conductor crimping pieces has a folded piece that is folded back by a folded part and has a gap on the inside, and the conductor crimping portion is crimped by an external crimping and fixing device to fix the conductor of an electric wire, the method comprising the steps of: a first step of placing the conductor on the bottom of the conductor crimping portion; and a second step of crimping the conductor crimping portion by the crimping and fixing device, the conductor crimping portion being raised by the crimping and fixing device so that the outer surfaces of the folded pieces on both sides face each other. a second step of pressing the folded pieces on both sides inward from the sides to bring the outer surfaces of the folded pieces into close contact with each other, thereby forming a closed space between the conductor crimping piece and the conductor; a third step of pressing the folded pieces on both sides inward from the sides with the crimping and fixing device to crush the gap and reduce the volume of the sealed space; and a fourth step of pressing the folded portions and the bottom of the conductor crimping piece inward from the outside with the crimping and fixing device to bring the conductor crimping piece, the bottom and the conductor into close contact with each other, thereby substantially closing the volume of the closed space. [Effects of the Invention]

[0008] According to the conductor crimping method for a crimp connection terminal of the present invention, a folded piece having a gap at its tip is used, and by following steps 1 to 4, the conductor is firmly clamped to the conductor by the conductor crimping piece around the conductor using a conductor crimping device, thereby obtaining strong fixing force and good conductivity. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 2 is a perspective view of a crimp connection terminal used in the embodiment. [Figure 2] FIG. 10 is a cross-sectional view of a conductor crimping piece raised in a V-shape. [Figure 3] FIG. 10 is a cross-sectional view showing a state in which a conductor is placed between the conductor crimping pieces in a first step. [Figure 4] FIG. 10 is a cross-sectional view showing a state in which the conductor is surrounded by the conductor crimping pieces in a second step. [Figure 5] FIG. 10 is a cross-sectional view showing a state in which the conductor is surrounded by the conductor crimping pieces in a third step. [Figure 6] FIG. 10 is a cross-sectional view showing a state in which the conductor is surrounded by the conductor crimping pieces in a fourth step. [Figure 7] FIG. 10 is a perspective view of the crimp connection terminal in a state where an electric wire is connected through first to fourth steps. [Figure 8] FIG. 10 is a cross-sectional view of a typical crimp-fixing structure for a conductor. [Figure 9] FIG. 10 is a cross-sectional view of a conductor crimping piece of a conventional crimp connection terminal. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described in detail based on the embodiments shown in FIGS.

[0011] 1 is a perspective view of a crimp connection terminal 1 used in this embodiment. This crimp connection terminal 1 is made of a thin copper alloy plate, for example, 0.2 mm thick, and is formed by punching a single conductive metal plate, both surfaces of which have been pre-plated with copper or tin, into a predetermined shape, and then bending the plate to form the connection end, crimping portion, etc.

[0012] A connecting end 2, which is, for example, a male insertion portion that fits with a connecting terminal of a mating connector, is formed on the longitudinal front side of the crimp connection terminal 1, and a conductor crimping portion 3 and an insulation crimping portion 4 are arranged in sequence on the rear side. An actual crimp connection terminal 1 may be provided with a stabilizer to stabilize its position within the connector housing, a locking portion to prevent it from slipping out of the connector housing in the forward and backward directions, etc., but these well-known mechanisms are not shown in the drawings.

[0013] The crimp connection terminal 1 is made from a conductive metal plate that has been chamfered or surface-treated as necessary and punched into a predetermined shape as described above, and is intermittently transported by a feed piece. During the transport process, the connection end 2, conductor crimping portion 3, and insulation crimping portion 4 are bent and formed from the conductive metal plate sequentially or simultaneously through each forming process using a forming press. After forming, the insulation crimping portion 4 is cut from the connecting piece and feed piece, and each crimp connection terminal 1 is separated.

[0014] As shown in Figure 1, the connecting end 2 has bent pieces 2b and 2c bent upward from both sides of the bottom plate 2a, and the edges of the bent pieces 2b and 2c are butted together to form a male insertion end with a two-layer structure. Note that the connecting end 2 may also be a male or female receptacle connecting end.

[0015] 2, in the conductor crimping portion 3, a pair of conductor crimping pieces 3a, 3b are raised on both sides from a bottom portion 3c in a V-shape. At the upper end of each of the conductor crimping pieces 3a, 3b, a folded piece 3e is provided, with the tip portion folded inward at a folded portion 3d. A parallel gap 3f is formed inside each of these folded pieces 3e.

[0016] In the coating crimping portion 4, a pair of insulating coating pieces 4a, 4b are raised on both sides from a bottom portion 4c in a V-shape.

[0017] When using this crimp connection terminal 1 to crimp a single conductor 5, first, in the first step, as shown in Figure 3, the conductor 5, which has a circular cross section and is made of copper wire with a diameter of, for example, 0.3 mm, is inserted and placed on the bottom 3c between the conductor crimping pieces 3a and 3b of the conductor crimping portion 3. The conductor 5 is the core wire of an electric wire, and is covered with an insulating coating layer made of synthetic resin, but in the first step, the conductor 5 is stripped and exposed from the insulating coating layer.

[0018] In the crimping process using the crimp connection terminal 1 on the conductor 5, which will be described below, the conductor crimping piece portion 3 is placed between the upper press mold and the lower press mold of the conductor crimping device (not shown), and the upper press mold is lowered and the lower press mold is raised relative to each other.

[0019] In the second step, by operating these upper and lower press dies, the conductor crimping pieces 3a, 3b are further raised according to the shape of the upper and lower press dies as shown in Figure 4, the outer surfaces of the bent pieces 2b, 2c on both sides are made to face each other, and the conductor crimping pieces 3a, 3b are pressed from the left and right directions, deforming them to encase the conductor 5.

[0020] In this second step, the outer surfaces of the folded pieces 3e of the left and right conductor crimping pieces 3a, 3b approach each other and butt against each other in a palm-to-palm manner, forming a closed space S between the conductor 5 and the conductor crimping pieces 3a, 3b.

[0021] 5, the folded pieces 3e of the conductor crimping pieces 3a, 3b are further pressed from both the left and right sides by lowering the upper press die, crushing them so that the gaps 3f are tightly packed together, thereby reducing the volume of the closed space S. Note that, although it is possible to crush the gaps 3f in the conductor crimping pieces 3a, 3b in advance, if a crimp connection terminal without the gaps 3f is used, the conductor crimping pieces 3a, 3b will not have enough flexibility when deforming, and the conductor crimping pieces 3a, 3b will not undergo sufficient plastic deformation in the third step.

[0022] Furthermore, in the fourth step, the upper press die and the lower press die are brought closer to each other to press the bottom portion 3c upward as shown in FIG. 6, and at the same time, press the folded portions 3d of the conductor crimping pieces 3a, 3b downward.

[0023] The bottom portion 3c and the folded portion 3d are pressed from the outside to the inside by the conductor crimping device, thereby crushing the gap 3f and almost closing the closed space S. Then, by almost closing the closed space S, the conductor crimping pieces 3a, 3b, the bottom portion 3c and the conductor 5 are tightly adhered to each other. At this time, the conductor 5 is plastically deformed, and the conductor crimping pieces 3a, 3b and the bottom portion 3c are also plastically deformed, so that they are tightly adhered to each other.

[0024] FIG. 7 shows a state in which the conductor 5 of the electric wire 6 is crimped and connected by the conductor crimping portion 3, and the insulating coating layer 7 of the electric wire 6 is crimped and fixed by the coating crimping portion 4.

[0025] In the conductor crimping portion 3, the conductor 5 is fixed by being firmly crimped by the surrounding conductor crimping pieces 3a, 3b, and in this process, the gap 3f formed in the conductor crimping pieces 3a, 3b is crushed, but the shape of this gap 3f is not particularly limited.

[0026] Furthermore, in the coating crimping portion 4, the insulating coating layer 7 is crimped from the outside by the pair of coating crimping pieces 4a, 4b of the coating crimping portion 4 using a coating crimping device with a press die that works in conjunction with the conductor crimping device, thereby crimping the insulating coating layer 7 so that the tips of the coating crimping pieces 4a, 4b bite into the insulating coating layer 7. This allows the insulating coating layer 7 to be firmly fixed by the coating crimping portion 4 and to withstand the pull-out force acting on the wire 6.

[0027] The terms up and down, left and right, front and back used in this specification are used for explaining the drawings and do not limit the present invention. [Explanation of symbols]

[0028] 1 crimp connection terminal 2 Connection end 3 Conductor crimping section 3a, 3b Conductor crimping pieces 3c bottom 3d folded part 3e Folding piece 3f gap 4 Covering crimp part 4a, 4b Covered crimp piece 5 Conductors 6 electric wire 7. Insulating coating layer S closed space

Claims

1. A conductor crimping method for a crimp connection terminal, comprising: a pair of conductor crimping pieces extending from a bottom in a V-shape on both sides; a conductor crimping portion having a folded piece at each end of the conductor crimping pieces, the folded piece being folded back at a folded portion with a gap on the inside; and a crimping method for a crimp connection terminal, comprising the steps of: crimping the conductor crimping portion with an external crimping and fixing device; and fixing the conductor of an electric wire; a first step of placing the conductor on the bottom of the conductor crimping portion; a second step of using the crimping and fixing device to raise the conductor crimping pieces so that the outer surfaces of the folded pieces on both sides face each other, and then pressing the folded pieces on both sides inward from the sides to bring the outer surfaces of the folded pieces into close contact with each other, thereby forming a closed space between the conductor crimping pieces and the conductor; a third step of pressing the folded pieces on both sides inward from the sides by the crimping and fixing device to crush the gap and reduce the volume of the sealed space; a fourth step of pressing the folded-back portion and the bottom portion of the conductor crimping piece from the outside to the inside by the crimping and fixing device to bring the conductor crimping piece, the bottom portion and the conductor into close contact with each other, thereby substantially closing the volume of the closed space; A method for crimping a conductor into a crimp connection terminal, comprising:

2. 2. The method for crimping a conductor into a crimp connection terminal according to claim 1, wherein the crimping and fixing device comprises an upper press die and a lower press die.

3. 3. The method for crimping a conductor of a crimp connection terminal according to claim 1, wherein the conductor is made of a single metal wire.

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