Method of joining electric wire with terminal and wire harness

Abstract

To provide a bonding method of an electric wire with a terminal capable of suppressing transmission of ultrasonic vibration to the terminal via a conductor part when the conductor parts of respective electric wires are ultrasonically bonded to each other, and to provide a wire harness.SOLUTION: A method for joining a terminal-equipped electric wire includes a step of attaching terminal fittings 13, 23, 33, and 43 to one ends of electric wires 10, 20, 30, and 40 in which conductor portions 11, 21, 31, and 41 are covered with coating portions 12, 22, 32, and 42, respectively, and a step of applying cured resins 51 and 52 so as to coat the exposed conductor portions 11, 21, 31, and 41 at the other ends of the electric wires 10, 20, 30, and 40. The method includes a curing step, a step of overlapping the conductor portions 11, 21, 31, and 41 of the electric wires 10, 20, 30, and 40 at the distal ends with respect to the cured resins 51 and 52 in a state where the cured resins 51 and 52 are not fixed, and a step of performing ultrasonic bonding by applying ultrasonic vibration to the conductor portions 11, 21, 31, and 41 at the distal ends with respect to the cured resins 51 and 52.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for joining electric wires with terminals and a wire harness. [Background technology]

[0002] The present applicant has proposed a method for joining electric wires with terminals, and a wire harness, in which multiple electric wires with terminals attached to one end are bundled together and the conductor portions exposed from the coating of each electric wire are ultrasonically joined together (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-177863 Summary of the Invention [Problem to be solved by the invention]

[0004] The method of joining an electric wire with a terminal described in Patent Document 1 has the excellent effect of attenuating the ultrasonic vibrations by the plates that hold the electric wire, thereby reducing the impact on the terminal fittings. However, in recent years, there has been a demand for further reducing the impact on the terminal fittings when ultrasonically joining electric wires.

[0005] 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, and a wire harness, which can further reduce the influence on the terminal fittings when ultrasonically joining the electric wires. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the method for joining an electric wire with a terminal according to the present invention has the following features. a step of attaching a terminal fitting to one end of an electric wire whose conductor portion is covered with a coating portion; applying a curable resin to cover the exposed conductor portion at the other end of the electric wire and curing the resin; overlapping the conductor portions of the plurality of electric wires at the ends beyond the cured resin without fixing the cured resin; and applying ultrasonic vibration to the conductor portion further forward than the cured resin to perform ultrasonic bonding. A method for joining terminal-attached wires.

[0007] In order to achieve the above-mentioned object, the method for joining an electric wire with a terminal according to the present invention is characterized as follows. a step of attaching a terminal fitting to one end of an electric wire whose conductor portion is covered with a coating portion; applying a curable resin to cover the exposed conductor portion at the other end of the electric wire and curing the resin; a step of overlapping the conductor portions of the plurality of electric wires at the tip end of the cured resin while the cured resin applied to the plurality of electric wires is collectively fixed; and applying ultrasonic vibration to the conductor portion further forward than the cured resin to perform ultrasonic bonding. A method for joining terminal-attached wires.

[0008] In order to achieve the above-mentioned object, the wire harness according to the present invention has the following features. A wire harness having a plurality of terminal-equipped electric wires connected to each other, The electric wire with terminal has a conductor portion, a covering portion that covers the conductor portion, and a terminal attached to one end thereof, The conductor portions of the plurality of terminal-attached electric wires are exposed from the other ends, the exposed conductor portions are joined together, and the conductor portions on the one end side of the joined portion are covered with a cured resin. Wire harness. [Effects of the Invention]

[0009] The method for joining an electric wire with a terminal and the wire harness according to the present invention have the effect of further reducing the influence on the terminal fittings when ultrasonically joining electric wires.

[0010] The present invention has been briefly described above. The details of the present invention will become clearer by reading the following detailed description of the invention (hereinafter referred to as "embodiments") with reference to the accompanying drawings. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is an overall perspective view showing a wire harness according to a first embodiment of the present invention. [Figure 2] FIG. 2 is an enlarged view of a main part showing the method for joining an electric wire with a terminal according to the first embodiment of the present invention. [Figure 3] FIG. 3 is a cross-sectional view taken along line AA shown in FIG. [Figure 4] FIG. 4 is an enlarged view of a main part showing the operation of the method for joining an electric wire with a terminal according to the first embodiment of the present invention. [Figure 5] FIG. 5 is an enlarged view of a main part showing a method for joining an electric wire with a terminal according to a second embodiment of the present invention. [Figure 6] FIG. 6 is a cross-sectional view taken along line BB shown in FIG. [Figure 7] FIG. 7 is an enlarged view of a main part showing a method for joining electric wires with a terminal according to a second embodiment of the present invention. [Figure 8] FIG. 8 is a cross-sectional view taken along line CC shown in FIG. [Figure 9] 10 is an enlarged view of a main part showing a modified example of the resin application form in the method for joining an electric wire with a terminal according to the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] Specific embodiments of the present invention will be described below with reference to the accompanying drawings.

[0013] First Embodiment Hereinafter, a method for joining an electric wire with a terminal and a wire harness according to a first embodiment of the present invention will be described with reference to the drawings. As shown in Fig. 1, the wire harness 1 has electric wires 10, 20, 30, and 40, which are electric wires with terminals. The electric wires 10, 20, 30, and 40 each have a conductor portion 11, 21, 31, and 41, a covering portion 12, 22, 32, and 42 that covers the conductor portion 11, 21, 31, and 41, and a terminal fitting 13, 23, 33, and 43 attached to one end. The conductor portions 11, 21, 31, and 41 are each composed of a plurality of wires.

[0014] In the electric wire 30, the diameters of the conductor portion 31 and the covering portion 32 are smaller than the diameters of the conductor portions 11, 21, 41 and the covering portions 12, 22, 42 of the electric wires 10, 20, 40. In addition, in the electric wires 20, 40, the diameters of the conductor portions 21, 41 and the covering portions 22, 42 are larger than the diameters of the conductor portion 31 and the covering portion 32 of the electric wire 30, but smaller than the diameters of the conductor portion 11 and the covering portion 12 of the electric wire 10. The materials of the conductor portions 11, 21, 31, 41 may be any material and do not need to be the same material.

[0015] These electric wires 10, 20, 30, 40 have exposed portions 14, 24, 34, 44 at the other end opposite to the end to which the terminal fittings 13, 23, 33, 43 are attached, where the conductor portions 11, 21, 31, 41 are exposed. In the exposed portions 14, 24, 34, 44, the conductor portions 11, 21, 31, 41 are stacked in parallel with each other and ultrasonically bonded to form a branch portion 50. In this embodiment, the exposed portions 14, 24 are stacked with the end faces of the conductor portions 11, 21 facing the same direction (toward the right in FIG. 1). The exposed portions 34, 44 are stacked with the end faces of the conductor portions 31, 41 facing the same direction (toward the left in FIG. 1). The end faces of the conductor portions 11, 21 and the end faces of the conductor portions 31, 41 are stacked with their end faces facing in opposite directions.

[0016] The electric wires 10 and 20 are covered with a cured resin 51 at the exposed portions 14 and 24 on the terminal fittings 13 and 23 side (one end side) of the branch portion 50. The electric wires 30 and 40 are covered with a cured resin 52 at the exposed portions 34 and 44 on the terminal fittings 33 and 43 side of the branch portion 50.

[0017] The curable resin 51 is applied so as to collectively cover the exposed portions 14, 24. The curable resin 52 is applied so as to collectively cover the exposed portions 34, 44. Examples of the curable resins 51, 52 include a thermosetting resin and an ultraviolet (UV) curable resin. In the wire harness 1, a branch portion 50 including the other end sides of the covered portions 12, 22, 32, 42 is covered with an insulating member 53 such as an insulating cover or an insulating tube.

[0018] <Process of the first embodiment> Next, a manufacturing process of the wire harness 1, which is a method for joining electric wires with terminals according to the present invention, will be described. First, a process of attaching terminal fittings 13, 23, 33, 43 to one ends of electric wires 10, 20, 30, 40, each having conductor portions 11, 21, 31, 41 covered with coating portions 12, 22, 32, 42, is performed. Next, as shown in Fig. 2, exposed portions 14, 24, 34, 44, where conductor portions 11, 21, 31, 41 are exposed at the other ends of the electric wires 10, 20, 30, 40, are stacked with the end faces of conductor portions 11, 21 facing the same direction (toward the right in Fig. 2), and exposed portions 34, 44 are stacked with the end faces of conductor portions 31, 41 facing the same direction (toward the left in Fig. 2). The end faces of conductor portions 11, 21 and conductor portions 31, 41 are stacked with their end faces facing in opposite directions.

[0019] Thereafter, cured resins 51 and 52 are applied to cover the conductor portions 11, 21, 31, and 41. At this time, the cured resins 51 and 52 are applied so that the ends of the coatings 12, 22, 32, and 42 are exposed. As shown in FIG. 3, the cured resin 51 is applied to collectively cover the conductor portions 11 and 21 of the electric wires 10 and 20. Note that while FIG. 3 shows the cured resin 51, the cured resin 52 (not shown) is also applied to collectively cover the conductor portions 31 and 41 of the electric wires 30 and 40.

[0020] The amount and area of ​​application of the cured resins 51, 52 are arbitrary as long as they are an amount that ensures reliable adhesion of the cured resins 51, 52 to the conductor portions 11, 21, 31, 41, and satisfies the conditions for ensuring reliable watertightness without causing any problems when attaching the insulating member 53 in a subsequent step. Furthermore, the order of the step of overlapping the exposed portions 14, 24, 34, 44 of the electric wires 10, 20, 30, 40 and the step of applying the cured resins 51, 52 to the conductor portions 11, 21, 31, 41 may be reversed.

[0021] 2, next, a process is performed in which the curable resins 51, 52 are cured by heat treatment or ultraviolet (UV) irradiation. Thereafter, the curable resins 51, 52 in the exposed portions 14, 24, 34, 44 are clamped between the cured resins 51, 52 with an anvil 54 and a horn 55, and ultrasonic vibrations are applied at a predetermined frequency for a predetermined time, thereby locally ultrasonically joining the exposed portions 14, 24, 34, 44. Then, the branch portion 50 including the other end sides of the conductor portions 11, 21, 31, 41 is covered with an insulating member 53 (see FIG. 1), such as an insulating cover or an insulating tube, to obtain the wire harness 1.

[0022] <Operation of the First Embodiment> 4 shows the propagation of ultrasonic vibrations when the exposed portions 14, 24, 34, and 44 are ultrasonically joined. For convenience, FIG. 4 shows only the electric wires 10 and 20, but the same applies to the electric wires 30 and 40 (not shown). As shown in FIG. 4, the electric wires 10 and 20 are clamped by the anvil 54 and the horn 55, and energy (mΩ) is applied to the portions of the electric wires 10 and 20 when the exposed portions 14 and 24 of the electric wires 10 and 20 are ultrasonically joined. 2 / 2 (m: mass of the electric wires 10, 20, ω: angular frequency of the electric wires 10, 20) is applied, causing the conductors 11, 21 to vibrate.

[0023] The mass of the conductors 11, 21 increases by the amount of the cured resin 51 at the locations where the cured resin 51 is in close contact. Therefore, the cured resin 51 and the conductors 11, 21 vibrate together within the cured resin 51. The angular frequency of the electric wires 10, 20 decreases accordingly (the angular frequency attenuates). As a result, ω1 (the angular frequency of the electric wire 10 before the cured resin propagates) > ω3 (the angular frequency of the electric wire 10 after the cured resin propagates) and ω2 (the angular frequency of the electric wire 20 before the cured resin propagates) > ω4 (the angular frequency of the electric wire 20 after the cured resin propagates). It can be seen that even when the exposed portions 14, 24 of the electric wires 10, 20 are joined by ultrasonic welding, the energy of the ultrasonic vibrations is not easily transmitted to the terminal fittings 13, 23. This decrease in the angular frequency of the electric wires 10, 20 (the angular frequency attenuates) can be obtained by adjusting the application amount, application area, etc. of the cured resins 51, 52.

[0024] Furthermore, ultrasonic vibrations propagate from the electric wires 10 and 20 to the cured resin 51. The electric wires 10 and 20, with their end faces facing the same direction, have conductors 11 and 21 with different diameters or made of different materials. As a result, the ultrasonic vibrations propagating from the electric wires 10 and 20 are attenuated because they have different phases. This also shows that the energy of the ultrasonic vibrations is less likely to propagate to the terminal fittings 13 and 23.

[0025] <Effects of the first embodiment> As described above, the method for joining electric wires with a terminal according to the first embodiment of the present invention includes the steps of applying and curing cured resins 51 and 52 so as to cover conductor portions 11, 21, 31, and 41, overlapping conductor portions 11, 21, 31, and 41 of a plurality of electric wires 10, 20, 30, and 40 that are further forward than cured resins 51 and 52 without fixing cured resins 51 and 52, and ultrasonically joining them by applying ultrasonic vibrations to conductor portions 11, 21, 31, and 41 that are further forward than cured resins 51 and 52. Therefore, the local mass increase caused by cured resins 51 and 52 reduces the angular frequency of electric wires 10, 20, 30, and 40 (attenuating the angular frequency), and as a result, the energy of the ultrasonic vibrations during ultrasonic joining is less likely to propagate to terminal fittings 13, 23, 33, and 33.

[0026] Furthermore, according to the method for joining electric wires with terminals of the first embodiment of the present invention, the cured resin 51 is applied so as to collectively cover the conductor portions 11, 21 of the multiple electric wires 10, 20, and the cured resin 52 is applied so as to collectively cover the conductor portions 31, 41 of the multiple electric wires 30, 40, thereby simplifying the work of applying the cured resins 51, 52.

[0027] Furthermore, according to the method for joining electric wires with terminals according to the first embodiment of the present invention, the conductor portions 11, 21 of the multiple electric wires 10, 20 are stacked with their end faces facing the same direction. These conductor portions 11, 21 have different diameters or are made of different materials. Furthermore, the conductor portions 31, 41 of the multiple electric wires 30, 40 are stacked with their end faces facing the same direction. These conductor portions 31, 41 have different diameters or are made of different materials. This makes it even more difficult for the energy of ultrasonic vibrations to propagate to the terminal fittings 13, 23, 33, 34 during ultrasonic joining.

[0028] Furthermore, according to the wire harness 1 of the first embodiment of the present invention, the conductor portions 11, 21, 31, 41 of the multiple electric wires 10, 20, 30, 40 are joined together, and the conductor portions 11, 21, 31, 41 on one end side of the joined portion are covered with cured resins 51, 52. Therefore, the local increase in mass due to the cured resins 51, 52 reduces the angular frequency of the electric wires 10, 20, 30, 40 (attenuates the angular frequency), and as a result, the energy of the ultrasonic vibrations during ultrasonic joining is less likely to be transmitted to the terminal fittings 13, 23.

[0029] Second Embodiment Next, a method for joining an electric wire with a terminal and a wire harness according to a second embodiment of the present invention will be described. In the second embodiment described below, the same reference numerals will be used in the drawings to simplify or omit the description of the components already described in the first embodiment.

[0030] 5 and 6, in the wire harness 2, the electric wires 10 and 20 are coated and cured with a curable resin 56 so as to collectively coat the conductor portions 11 and 21, including the ends of the coating portions 12 and 22, at the exposed portions 14 and 24 on one end side of the branch portion 50. Note that in FIGS. 5 and 6, the curable resin is also coated and cured in the same manner for the electric wires 30 and 40, which are not shown.

[0031] <Process of the second embodiment> Next, a manufacturing process of the wire harness 2, which is a method for joining electric wires with terminals according to the present invention, will be described. As in the first embodiment, a process of attaching terminal fittings 13, 23, 33, 43 to one ends of electric wires 10, 20, 30, 40, in which conductor portions 11, 21, 31, 41 are covered with covering portions 12, 22, 32, 42, is performed as shown in Fig. 7. Next, as shown in Fig. 7, exposed portions 14, 24, 34, 44, in which conductor portions 11, 21, 31, 41 are exposed at the other ends of the electric wires 10, 20, 30, 40, are stacked with the end faces of the conductor portions 11, 21 facing the same direction (toward the right in Fig. 7), and exposed portions 34, 44 are stacked with the end faces of the conductor portions 31, 41 facing the same direction (toward the left in Fig. 7).

[0032] Next, curable resins 56 and 57 are applied to cover the conductor portions 11, 21, 31, and 41, and then a process is performed in which the curable resins 56 and 57 are cured by heat treatment or ultraviolet (UV) irradiation. At this time, the curable resin 56 is applied to cover the ends of the coatings 12 and 22, and the curable resin 57 is applied to cover the ends of the coatings 32 and 42. The amount and area of ​​application of the curable resins 56 and 57 are arbitrary. Furthermore, the order of the step of overlapping the exposed portions 14, 24, 34, and 44 of the electric wires 10, 20, 30, and 40 and the step of applying the curable resins 56 and 57 to the conductor portions 11, 21, 31, and 41 may be reversed.

[0033] Next, the cured resins 56 and 57 are fixed by a clamping member 59 having a pair of fixing devices 58. Specifically, as shown in Fig. 8, the pair of fixing devices 58 move toward and away from each other along a base member 60 to clamp the cured resin 56. Note that Fig. 8 shows the cured resin 56, but the cured resin 57 (not shown) is also clamped by the clamping member 59 in the same manner.

[0034] 7, the cured resins 56, 57 in the exposed portions 14, 24, 34, 44 are clamped between anvil 54 and horn 55, and ultrasonic vibrations are applied at a predetermined frequency for a predetermined time, thereby locally ultrasonically joining the exposed portions 14, 24, 34, 44. Then, branched portion 50 including the other end sides of conductor portions 11, 21, 31, 41 is covered with an insulating member (not shown), such as an insulating cover or an insulating tube, to obtain wire harness 2.

[0035] <Effects of the second embodiment> As described above, according to the method for joining electric wires with a terminal of the second embodiment of the present invention, the angular frequency of the electric wires 10, 20, 30, 40 decreases (the angular frequency attenuates) due to the local increase in mass caused by the cured resins 56, 57, and as a result, the energy of the ultrasonic vibrations during ultrasonic joining is less likely to propagate to the terminal fittings. Furthermore, according to the method for joining electric wires with a terminal of the second embodiment of the present invention, the cured resins 56, 57 are applied so as to collectively cover the conductor portions 11, 21, 31, 41 of the plurality of electric wires 10, 20, 30, 40, and therefore the application work of the cured resins 56, 57 can be simplified. Furthermore, according to the method for joining electric wires with terminals of the second embodiment of the present invention, the conductor portions 11, 21 of multiple electric wires 10, 20 are stacked with their end faces facing the same direction, and the conductor portions 31, 41 of multiple electric wires 30, 40 are stacked with their end faces facing the same direction, and since these conductor portions 11, 21, 31, 41 have different diameter dimensions or are made of different materials, the joining process can be carried out smoothly even if the conductor portions 11, 21, 31, 41 have different diameter dimensions or are made of different materials.

[0036] Furthermore, the method for joining electric wires with a terminal according to the second embodiment of the present invention includes a step of overlapping the conductor portions of the electric wires 10, 20, 30, 40 that are further distal than the cured resins 56, 57 while the cured resins 56, 57 applied to the electric wires 10, 20, 30, 40 are collectively fixed, which generates friction between the cured resins 56, 57 and the fixture 58. Therefore, according to the method for joining electric wires with a terminal according to the second embodiment of the present invention, the energy of the ultrasonic vibrations during ultrasonic joining is converted into heat energy generated by the fixture 58, which has the effect of making it even more difficult for the energy of the ultrasonic vibrations during ultrasonic joining to propagate to the terminal fittings compared to the first embodiment described above.

[0037] <Other forms> It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be adopted within the scope of the present invention. For example, the present invention is not limited to the above-described embodiments, and modifications, improvements, etc. are possible as appropriate. Furthermore, the material, shape, dimensions, number, location, etc. of each component in the above-described embodiments are arbitrary and not limited as long as the present invention can be achieved.

[0038] For example, the present invention also includes a wire harness 3 shown in Fig. 9. That is, in the wire harness 3, the conductor portions 11, 21 of the electric wires 10, 20 are covered with individual cured resins 51A, 51B, respectively. In such a wire harness 3, the electric wires 10, 20 have conductor portions 11, 21 with different diameters, and therefore, appropriate amounts or materials of cured resins 51A, 51B can be applied individually to the electric wires 10, 20. This reduces the amount of cured resin used and allows selection of a cured resin that is optimal for the material of the conductor portions 11, 21.

[0039] Here, the features of the embodiments of the method for joining an electric wire with a terminal and the wire harness according to the present invention will be briefly summarized and listed below in [1] to [5].

[0040] [1] a step of attaching a terminal fitting (13, 23, 33, 43) to one end of an electric wire (10, 20, 30, 40) whose conductor portion (11, 21, 31, 41) is covered with a covering portion (12, 22, 32, 42); a step of applying a curable resin (51, 52) to cover the conductor portion (11, 21, 31, 41) exposed at the other end of the electric wire (10, 20, 30, 40) and curing the resin; a step of overlapping the conductor portions (11, 21, 31, 41) of the plurality of electric wires (10, 20, 30, 40) at the ends of the cured resin (51, 52) without fixing the cured resin (51, 52); and applying ultrasonic vibration to the conductor portion (11, 21, 31, 41) distal to the cured resin (51, 52) to perform ultrasonic bonding. A method for joining terminal-attached wires.

[0041] According to the method for joining electric wires with terminals having the configuration [1] above, the angular frequency of the electric wires (10, 20, 30, 40) decreases (the angular frequency attenuates) due to the local increase in mass caused by the cured resin (51, 52), and as a result, the energy of the ultrasonic vibrations during ultrasonic joining is less likely to propagate to the terminal fittings (13, 23, 33, 43).

[0042] [2] a step of attaching a terminal fitting (13, 23, 33, 43) to one end of an electric wire (10, 20, 30, 40) whose conductor portion (11, 21, 31, 41) is covered with a covering portion (12, 22, 32, 42); a step of applying a curable resin (56, 57) to cover the conductor portion (11, 21, 31, 41) exposed at the other end of the electric wire (10, 20, 30, 40) and curing the resin; a step of overlapping the conductor portions (11, 21, 31, 41) of the plurality of electric wires (10, 20, 30, 40) at the ends of the cured resins (56, 57) applied to the plurality of electric wires (10, 20, 30, 40) in a state where the cured resins (56, 57) applied to the plurality of electric wires (10, 20, 30, 40) are collectively fixed; and applying ultrasonic vibration to the conductor portion (11, 21, 31, 41) distal to the cured resin (56, 57) to perform ultrasonic bonding. A method for joining terminal-attached wires.

[0043] According to the method for joining an electric wire with a terminal having the configuration [2] above, the energy of the ultrasonic vibrations during ultrasonic joining is converted into heat energy, which makes it even more difficult for the energy of the ultrasonic vibrations during ultrasonic joining to be transmitted to the terminal fittings (13, 23, 33, 43).

[0044] [3] In the method for joining an electric wire with a terminal according to the above [1] or [2], The cured resin (51, 52, 56, 57) is applied so as to collectively cover the conductor portions (11, 21, 31, 41) of the plurality of electric wires (10, 20, 30, 40). A method for joining terminal-attached wires.

[0045] According to the method for joining electric wires with terminals having the above configuration [3], the application work of the cured resin (51, 52, 56, 57) can be simplified.

[0046] [4] In the method for joining an electric wire with a terminal according to the above [1], The conductor portions (11, 21, 31, 41) of the plurality of electric wires (10, 20, 30, 40) are stacked with their end faces facing the same direction, The conductor portions (11, 21, 31, 41) of the plurality of electric wires (10, 20, 30, 40) stacked with the end faces of the conductor portions (11, 21, 31, 41) facing the same direction have different diameters or are made of different materials. A method for joining terminal-attached wires.

[0047] According to the method for joining electric wires with terminals having the configuration [4] above, these conductors (11, 21, 31, 41) have different diameters or are made of different materials, which makes it even more difficult for the energy of ultrasonic vibrations to propagate to the terminal fittings during ultrasonic joining.

[0048] [5] A wire harness (1, 2, 3) having a plurality of terminal-equipped electric wires (10, 20, 30, 40) connected to each other, The electric wire with terminal (10, 20, 30, 40) has a conductor portion (11, 21, 31, 41), a covering portion (12, 22, 32, 42) that covers the conductor portion (11, 21, 31, 41), and a terminal fitting (13, 23, 33, 43) attached to one end thereof, The conductor portions (11, 21, 31, 41) of the plurality of terminal-attached electric wires (10, 20, 30, 40) are exposed from the other ends, the exposed conductor portions (11, 21, 31, 41) are joined together, and the conductor portions (11, 21, 31, 41) on the one end side relative to the joined portion are covered with a cured resin (51, 51A, 51B, 52, 56, 57). Wire harness (1, 2, 3).

[0049] According to the wire harness (1, 2, 3) having the configuration [5] above, the local increase in mass due to the cured resin (51, 51A, 51B, 52, 56, 57) reduces the angular frequency of the electric wires (10, 20, 30, 40) (attenuates the angular frequency), and as a result, the energy of the ultrasonic vibration during ultrasonic bonding is less likely to propagate to the terminal fittings (13, 23, 33, 43). [Explanation of symbols]

[0050] 1, 2, 3 Wire harness 10, 20, 30, 40 wires (wires with terminals) 11, 21, 31, 41 Conductor part 12, 22, 32, 42 Covering part 51, 51, 51A, 52, 56, 57 Cured resin 13, 23, 33, 43 terminal fittings

Claims

1. a step of attaching a terminal fitting to one end of an electric wire whose conductor portion is covered with a coating portion; applying a curable resin to cover the exposed conductor portion at the other end of the electric wire and curing the resin; overlapping the conductor portions of the plurality of electric wires at the ends beyond the cured resin without fixing the cured resin; and applying ultrasonic vibration to the conductor portion further forward than the cured resin to perform ultrasonic bonding. A method for joining terminal-attached wires.

2. a step of attaching a terminal fitting to one end of an electric wire whose conductor portion is covered with a coating portion; applying a curable resin to cover the exposed conductor portion at the other end of the electric wire and curing the resin; a step of overlapping the conductor portions of the plurality of electric wires at the tip end of the cured resin while the cured resin applied to the plurality of electric wires is collectively fixed; and applying ultrasonic vibration to the conductor portion further forward than the cured resin to perform ultrasonic bonding. A method for joining terminal-attached wires.

3. The method for joining an electric wire with a terminal according to claim 1 or 2, The cured resin is applied so as to collectively cover the conductor portions of the plurality of electric wires. A method for joining terminal-attached wires.

4. The method for joining an electric wire with a terminal according to claim 1, The conductor portions of the plurality of electric wires are stacked with their end faces facing the same direction, The conductor portions of the plurality of electric wires stacked with the end faces of the conductor portions facing the same direction have different diameters or are made of different materials. A method for joining terminal-attached wires.

5. A wire harness having a plurality of terminal-equipped electric wires connected to each other, The electric wire with terminal has a conductor portion, a covering portion that covers the conductor portion, and a terminal fitting attached to one end thereof, The conductor portions of the plurality of terminal-attached electric wires are exposed from the other ends, the exposed conductor portions are joined together, and the conductor portions on the one end side of the joined portion are covered with a cured resin. Wire harness.

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