How to join wires with terminals

Abstract

To provide a method for bonding a terminal-equipped wire that suppresses deformation of a terminal when bonding conductor core wires.SOLUTION: A bonding method of a terminal-equipped wire includes a first step of providing a plurality of terminal-equipped wires 2, a horn 11, and an anvil 12, placing a conductor core wire of a first terminal-equipped wire 2a in the plurality of terminal-equipped wires 2 on the horn 11 and crushing the conductor core wire of the first terminal-equipped wire 2a by the horn 11 and the anvil 12, and a second step of placing the conductor core wire of a second terminal-equipped wire 2c of the plurality of terminal-equipped wires on the crushed conductor core wire and ultrasonically joining these conductor core wires using the horn 11 and the anvil 12.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a method for joining an electric wire with a terminal. [Background technology]

[0002] In general, power supplies and electrical equipment mounted on vehicles such as automobiles are often connected to each other by a wire harness that bundles together a plurality of electric wires with terminals. The plurality of electric wires with terminals that constitute this wire harness are electrically connected to each other, for example, by joining the conductor core wires exposed from the insulating coating.

[0003] Various methods for joining conductor core wires together as described above have been proposed in the past, one example being a joining method using ultrasonic vibrations with a horn and anvil (i.e., ultrasonic joining) (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-47422 A [Patent Document 2] JP 2020-136203 A Summary of the Invention [Problem to be solved by the invention]

[0005] By the way, ultrasonic bonding is a metal-metal fusion that is performed by applying ultrasonic vibrations to connection objects by a horn. Specifically, each conductor core wire of a plurality of terminal-attached electric wires is clamped by a horn and an anvil, and the overlapping portions of the conductor core wires are rubbed against each other by ultrasonic vibrations, so that they are joined in a solid state by plastic deformation, and a joint is formed.

[0006] For this reason, in the case of an electric wire with terminals, if the terminals attached to the electric wires have a thin plate thickness or an elastic body is used (i.e., an elastic body is provided) for connection with a connection part of a power supply device, an electrical equipment, etc., the terminals are likely to be deformed by the propagated ultrasonic vibration. In addition, depending on the terminal, even if the electric wire is short, ultrasonic vibration is likely to propagate, so deformation is likely to occur. In other words, if some of the multiple electric wires with terminals constituting a wire harness use terminals with low resistance to ultrasonic vibration as described above, there is a risk that the deformation of the terminals will cause poor contact with the connection parts of a power supply device, an electrical equipment, etc., and there is a concern that the connection reliability of the wire harness will decrease. In the following, an electric wire with terminals using terminals with low resistance to ultrasonic vibration will also be referred to as an "electric wire with terminals with low resistance to ultrasonic vibration."

[0007] The present invention has been made in consideration of the above-mentioned circumstances, and an object of the present invention is to provide a method for joining an electric wire with a terminal that suppresses deformation of the terminal when conductor core wires are joined to each other. [Means for solving the problem]

[0008] In order to achieve the above-mentioned object, a method for joining an electric wire with a terminal according to the present invention has the following features.

[0009] An electric wire with a first terminal and an electric wire with a second terminal having a terminal with a lower ultrasonic vibration resistance than the electric wire with the first terminal of A method for joining electric wires with a terminal by using a horn and an anvil, comprising the steps of: before a first step of placing a conductor core of the electric wire with the first terminal on the horn and crushing the conductor core of the electric wire with the first terminal by the horn and the anvil; On top of the crushed conductor core ,before and a second step of placing the conductor core wires of the electric wire with the second terminal and ultrasonically joining the conductor core wires by the horn and the anvil. It is a method for joining electric wires with terminals. Effect of the Invention

[0010] The method for joining electric wires with terminal according to the present invention will be described below. According to the joining method of electric wires with terminals of this configuration, in the first step, at least the conductor core of the first electric wire with terminal is placed on the horn and then crushed by the horn and anvil. Then, in the second step, at least the conductor core of the second electric wire with terminal is placed on the crushed conductor core including at least the conductor core of the first electric wire with terminal, and these conductor cores are ultrasonically joined. As a result, when the conductor cores are joined to each other, the conductor core of the second electric wire with terminal is placed on the crushed conductor core, and is therefore located at a position away from the horn. Here, ultrasonic vibration is generally applied by the horn, and the ultrasonic vibration propagating to the terminal of the electric wire with terminal is attenuated as it moves away from the horn. In other words, according to the joining method of electric wires with terminals of this configuration, by applying an electric wire with terminal with low ultrasonic vibration resistance as the second electric wire with terminal, the distance from the horn can be increased, and deformation of the terminal when the conductor cores are joined to each other can be suppressed.

[0011] The present invention has been briefly described above. Furthermore, the details of the present invention will be further clarified by reading the following description of the embodiment of the present invention (hereinafter, referred to as "embodiment") with reference to the accompanying drawings. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a schematic perspective view of a wire harness having a joint formed by a method for joining an electric wire with a terminal according to each embodiment of the present invention. [Diagram 2] FIG. 2 is a first schematic cross-sectional view for explaining the method for joining electric wires with a terminal according to the first embodiment. [Diagram 3] FIG. 3 is a second schematic cross-sectional view for explaining the method for joining electric wires with a terminal according to the first embodiment. [Figure 4] FIG. 4 is a third schematic cross-sectional view for explaining the method for joining electric wires with a terminal according to the first embodiment. [Diagram 5]FIG. 5 is a fourth schematic cross-sectional view for illustrating the method for joining electric wires with a terminal according to the first embodiment. [Figure 6] FIG. 6 is a schematic cross-sectional view of a joint formed by the method for joining an electric wire with a terminal according to the first embodiment. [Figure 7] FIG. 7 is a first schematic cross-sectional view for explaining the method for joining an electric wire with a terminal according to the second embodiment, and is also a first schematic cross-sectional view for explaining the method for joining an electric wire with a terminal according to the third embodiment. [Figure 8] FIG. 8 is a second schematic cross-sectional view for illustrating the method for joining electric wires with a terminal according to the second embodiment. [Figure 9] FIG. 9 is a schematic cross-sectional view of a joint formed by the method for joining an electric wire with a terminal according to the second embodiment. [Figure 10] FIG. 10 is a second schematic cross-sectional view for explaining the method for joining electric wires with a terminal according to the third embodiment. [Figure 11] FIG. 11 is a third schematic cross-sectional view for illustrating the method for joining electric wires with a terminal according to the third embodiment. [Figure 12] FIG. 12 is a schematic cross-sectional view of a joint formed by the method for joining an electric wire with a terminal according to the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] <Embodiment> Hereinafter, with reference to Fig. 1, a wire harness 1 having a joint 5 formed by a method for joining an electric wire with terminal 2 according to each embodiment of the present invention will be described. The wire harness 1 is configured by joining exposed conductor core wires of a plurality of electric wires with terminal 2 (three in this example) and electrically connected to each other. In other words, the wire harness 1 has a joint 5 formed therein. The wire harness 1 is used, for example, to connect power supplies, electrical equipment, etc. mounted on vehicles such as automobiles to each other.

[0014] Each of the multiple electric wires with terminals 2 (2a, 2b, 2c) has an electric wire 3 (3a, 3b, 3c) and a terminal 4 (4a, 4b, 4c) attached to an end of the electric wire 3. Each electric wire 3 has a conductor core wire (reference number omitted) and an insulating coating (reference number omitted) that covers the outer circumferential surface of the conductor core wire.

[0015] The electric wire with terminal 2a corresponds to the "first electric wire with terminal" of the present invention, and the electric wire with terminal 2c corresponds to the "second electric wire with terminal" of the present invention. For the sake of convenience, the terminal 4c in the electric wire with terminal 2c is assumed to have low resistance to ultrasonic vibration (easily deformed by ultrasonic vibration). The terminal 4a in the electric wire with terminal 2a is assumed to have high resistance to ultrasonic vibration (hardly deformed by ultrasonic vibration).

[0016] The methods for joining electric wires with terminal according to the first to third embodiments will be described in order below. Each method for joining electric wires with terminal according to each embodiment includes a plurality of electric wires with terminal 2 (2a, 2b, 2c), a horn 11, an anvil 12, and an ultrasonic joining machine 13.

[0017] First Embodiment 2 to 6, a method for joining an electric wire with terminal 2 according to a first embodiment of the present invention will be described below. First, in a first step, the conductor core wires of the electric wire with terminal 2a and the electric wire with terminal 2b are placed on a horn 11 (see FIG. 2), and the conductor core wires of the electric wire with terminal 2a and the electric wire with terminal 2b are ultrasonically joined by the horn 11 and anvil 12 (see FIG. 3).

[0018] At this time, the anvil 12 presses the conductor core wires of the electric wire with terminal 2a and the electric wire with terminal 2b toward the horn 11. As a result, the conductor core wires of the electric wire with terminal 2a and the electric wire with terminal 2b are crushed by the horn 11 and the anvil 12 (see FIG. 3).

[0019] Next, in a second step, the conductor core wire of the electric wire with terminal 2c is placed on top of the conductor core wires of the crushed (and ultrasonically joined) electric wire with terminal 2a and electric wire with terminal 2b (see FIG. 4), and the conductor core wires of the crushed electric wire with terminal 2a and electric wire with terminal 2b and the conductor core wire of the electric wire with terminal 2c are ultrasonically joined by a horn 11 and an anvil 12 (see FIG. 5).

[0020] At this time, the anvil 12 presses the conductor core wires of the electric wire with terminal 2a, the electric wire with terminal 2b, and the conductor core wire of the electric wire with terminal 2c toward the horn 11. As a result, the conductor core wires of the electric wire with terminal 2a, the electric wire with terminal 2b, and the conductor core wire of the electric wire with terminal 2c are crushed by the horn 11 and the anvil 12 (see FIG. 5).

[0021] As a result, the conductor core wires of the electric wires with terminal 2a, 2b, 2b are joined to each other to form a joint 5 (see FIG. 6). When there are four or more electric wires with terminal 2, in the first step, each conductor core wire of the electric wires with terminal 2 except for the electric wire with terminal 2c is placed on the horn 11 and these conductor core wires are crushed and ultrasonically joined, and then the second step is performed. The method for joining electric wires with terminal 2 according to the first embodiment has been described above.

[0022] <Second embodiment> Hereinafter, a method for joining an electric wire with terminal 2 according to a second embodiment of the present invention will be described with reference to Fig. 7 to Fig. 9. First, in a first step, the conductor core wire of the electric wire with terminal 2a is placed on a horn 11 (see Fig. 7), and the conductor core wire of the electric wire with terminal 2a is crushed by the horn 11 and anvil 12 (see Fig. 8).

[0023] Next, in a second step, the conductor core wires of the electric wire with terminal 2b and the electric wire with terminal 2c are placed on top of the crushed conductor core wire of the electric wire with terminal 2a (see FIG. 8), and the conductor core wire of the crushed electric wire with terminal 2a and the conductor core wires of the electric wire with terminal 2b and the electric wire with terminal 2c are ultrasonically joined by a horn 11 and an anvil 12.

[0024] At this time, the anvil 12 presses the conductor core wire of the electric wire with terminal 2a and the conductor core wires of the electric wire with terminal 2b and the electric wire with terminal 2c toward the horn 11. As a result, the conductor core wire of the electric wire with terminal 2a and the conductor core wires of the electric wire with terminal 2b and the electric wire with terminal 2c are crushed by the horn 11 and the anvil 12 (see FIG. 9).

[0025] As a result, the conductor core wires of the multiple electric wires with terminal 2a, 2b, 2b are joined to each other to form a joint 5 (see FIG. 9). When there are four or more electric wires with terminal 2, in the second step, the conductor core wires of the other electric wires with terminal 2 are placed on the conductor core wire of the crushed electric wire with terminal 2 together with the electric wire with terminal 2b and the electric wire with terminal 2c, and these conductor core wires are crushed and ultrasonically joined. The method for joining electric wires with terminal 2 according to the second embodiment has been described above.

[0026] <Third embodiment> Hereinafter, a method for joining an electric wire with terminal 2 according to a third embodiment of the present invention will be described with reference to Fig. 7 and Fig. 10 to Fig. 12. First, in a first step, the conductor core wire of the electric wire with terminal 2a is placed on a horn 11 (see Fig. 7), and the conductor core wire of the electric wire with terminal 2a is crushed by the horn 11 and anvil 12 (see Fig. 10).

[0027] Next, in the third step (the second step in order), the conductor core wire of the electric wire with terminal 2b is placed on top of the crushed conductor core wire of the electric wire with terminal 2a (see FIG. 10), and the conductor core wire of the crushed electric wire with terminal 2a and the conductor core wire of the electric wire with terminal 2b are ultrasonically joined by a horn 11 and an anvil 12.

[0028] At this time, the anvil 12 presses the conductor core wire of the electric wire with terminal 2a and the conductor core wire of the electric wire with terminal 2b toward the horn 11. As a result, the conductor core wire of the electric wire with terminal 2a and the conductor core wire of the electric wire with terminal 2b are crushed by the horn 11 and the anvil 12 (see FIG. 11).

[0029] Next, in the second step (the third step in order), the conductor core wire of the electric wire with terminal 2c is placed on the crushed (and ultrasonically joined) conductor core wire of the electric wire with terminal 2a and the conductor core wire of the electric wire with terminal 2b (see FIG. 11), and the crushed conductor core wire of the electric wire with terminal 2a, the conductor core wire of the electric wire with terminal 2b, and the conductor core wire of the electric wire with terminal 2c are ultrasonically joined by a horn 11 and an anvil 12.

[0030] At this time, the anvil 12 presses the conductor core wire of the electric wire with terminal 2a, the conductor core wire of the electric wire with terminal 2b, and the conductor core wire of the electric wire with terminal 2c toward the horn 11. As a result, the conductor core wire of the electric wire with terminal 2a, the conductor core wire of the electric wire with terminal 2b, and the conductor core wire of the electric wire with terminal 2c are crushed by the horn 11 and the anvil 12 (see FIG. 12).

[0031] As a result, the conductor core wires of the plurality of electric wires with terminals 2a, 2b, 2b are joined to one another, forming a joint portion 5 (see FIG. 12).

[0032] Here, when the number of electric wires with terminal 2 is N (N: an integer of 4 or more), the conductor core wire of one electric wire with terminal 2 (hereinafter referred to as "electric wire with terminal 2d"; not shown) is placed on the conductor core wire of the electric wire with terminal 2a and the conductor core wire of the electric wire with terminal 2b that were crushed in the third step, and the conductor core wire of the crushed electric wire with terminal 2a, the conductor core wire of the electric wire with terminal 2b, and the conductor core wire of the electric wire with terminal 2d are ultrasonically joined by the horn 11 and the anvil 12. At this time, it goes without saying that the conductor core wire of the electric wire with terminal 2a, the conductor core wire of the electric wire with terminal 2b, and the conductor core wire of the electric wire with terminal 2d are crushed by the horn 11 and the anvil 12.

[0033] Similarly, the crushing and ultrasonic bonding are performed N-4 times in the following steps. That is, in the third step, each conductor core wire of the electric wires with terminal 2 is ultrasonically bonded to the crushed conductor core wire one by one in order, and then the second step is performed. The above has described the bonding method for an electric wire with terminal 2 according to the third embodiment.

[0034] <Actions and Effects> The joining method of the electric wire with terminal 2 according to each embodiment will be described below. In general, ultrasonic vibration is applied by a horn, and therefore the ultrasonic vibration propagating through the electric wire with terminal is attenuated as it moves away from the horn. However, in the joining method of the electric wire with terminal 2 according to the present embodiment, by using an electric wire with terminal 2c having low resistance to ultrasonic vibration, the distance from the horn 11 can be increased, and deformation of the terminal 4c when joining the conductor core wires can be suppressed.

[0035] Furthermore, according to the method for joining an electric wire with terminal 2 in the third embodiment, in the third step between the first step and the second step, each conductor core wire of the multiple electric wires with terminal 2 is ultrasonically joined to the crushed conductor core wire one by one in order, so that the electric wires with terminal 2c can be moved away from the horn 11 in proportion to the number of the electric wires with terminal 2.

[0036] <Other forms> The present invention is not limited to the above-described embodiment, and can be appropriately modified, improved, etc. In addition, the material, shape, size, number, arrangement location, etc. of each component in the above-described embodiment are arbitrary as long as the present invention can be achieved, and are not limited.

[0037] Here, the features of the embodiments of the method for joining an electric wire with a terminal according to the present invention described above will be briefly summarized and listed in the following [1] to [4]. [1] A method for joining electric wires with terminals, comprising: a plurality of electric wires with terminals (2) each having a first electric wire with terminal (2a) and a second electric wire with terminal (2b); a horn (11); and an anvil (12), a first step of placing a conductor core of at least the first electric terminal (2a) among the plurality of electric wires with terminals on the horn (11) and crushing the conductor core of the first electric terminal (2a) by the horn (11) and the anvil (12); and a second step of placing a conductor core wire of at least the second terminal-attached electric wire (2c) among the plurality of terminal-attached electric wires on the crushed conductor core wire, and ultrasonically joining the conductor core wires by the horn (11) and the anvil (12). A method for joining wires with terminals. [2] In the method for joining an electric wire with a terminal according to the above [1], In the first step, each conductor core wire of the plurality of electric wires with terminals (2b) except for the electric wire with second terminal (2c) is placed on the horn (11) together with the conductor core wire of the electric wire with first terminal (2a), and these conductor core wires are crushed and ultrasonically joined by the horn (11) and the anvil (12). A method for joining wires with terminals. [3] In the method for joining an electric wire with a terminal according to the above [1], In the second step, the conductor core wires of the second terminal-attached electric wire (2c) and each of the terminal-attached electric wires (2b) are placed on the crushed conductor core wire, and these conductor core wires are ultrasonically joined by the horn (11) and the anvil (12). A method for joining wires with terminals. [4] A method for joining an electric wire with a terminal according to the above [1], and a third step between the first step and the second step, in which each of the conductor core wires of the plurality of electric wires with terminals is ultrasonically joined to the crushed conductor core wire one by one in order. A method for joining wires with terminals.

[0038] According to the joining method of electric wires with terminals having the configurations [1] to [3], in the first step, at least the conductor core of the electric wire with the first terminal is placed on the horn and then crushed by the horn and the anvil. Then, in the second step, at least the conductor core of the electric wire with the second terminal is placed on the crushed conductor core including at least the conductor core of the electric wire with the first terminal, and these conductor cores are ultrasonically joined. As a result, when the conductor cores are joined to each other, the conductor core of the electric wire with the second terminal is placed on the crushed conductor core, and is therefore located at a position away from the horn. Here, ultrasonic vibration is generally applied by the horn, and the ultrasonic vibration propagating to the terminal of the electric wire with terminal is attenuated as it moves away from the horn. In other words, according to the joining method of electric wires with terminals having the configuration, by applying an electric wire with terminal having low ultrasonic vibration resistance as the electric wire with the second terminal, the distance from the horn can be increased, and deformation of the terminal when the conductor cores are joined to each other can be suppressed.

[0039] According to the method for joining an electric wire with a terminal having the configuration [4] above, in the third step between the first and second steps, each conductor core of the multiple electric wires with terminals is ultrasonically joined to the crushed conductor core wire one by one in order, so that the second electric wire with terminal can be moved away from the horn in proportion to the number of electric wires with terminals. [Explanation of symbols]

[0040] 1 Wire Harness 2 Wire with terminals 2a Terminal Wire (1st Terminal Wire) 2b Wire with terminal 2c Terminal wire (2nd terminal wire) 3,3a,3b,3c electric wire 4,4a,4b,4c terminal 5 Joint 11 Horn 12 Anvil 13 Ultrasonic bonding machine

Claims

1. A method for joining an electric wire with a terminal, comprising the steps of: joining a first electric wire with a terminal and a second electric wire with a terminal having a lower ultrasonic vibration resistance than the first electric wire with a terminal, using a horn and an anvil, a first step of placing a conductor core of the electric wire with the first terminal on the horn and crushing the conductor core of the electric wire with the first terminal by the horn and the anvil; a second step of placing the conductor core wire of the second terminal-attached electric wire on the crushed conductor core wire and ultrasonically bonding the conductor core wires by the horn and the anvil, A method for joining wires with terminals.

2. The method for joining electric wires with terminals according to claim 1, In the first step, a conductor core wire of another electric wire with a terminal having a terminal with a higher ultrasonic vibration resistance than the second electric wire with a terminal is placed on the horn together with the conductor core wire of the first electric wire with a terminal, and the conductor core wires are crushed and ultrasonically joined by the horn and the anvil. A method for joining wires with terminals.

3. The method for joining electric wires with terminals according to claim 1, In the second step, the conductor core wire of the second electric terminal and each conductor core wire of another electric terminal are placed on the crushed conductor core wire, and these conductor core wires are ultrasonically joined by the horn and the anvil. A method for joining wires with terminals.

4. A method for joining an electric wire with a terminal according to claim 1, and a third step between the first step and the second step of ultrasonically joining a conductor core of another electric wire with a terminal to the crushed conductor core. A method for joining wires with terminals.

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