Manufacturing method of electric wire with terminal

Abstract

To suppress the occurrence of element wire rupture.SOLUTION: The method for manufacturing an electric wire with a terminal comprises: a junction blocking part formation step in which a junction blocking part 122b that causes ultrasonic junction to be blocked is formed in a portion of a core wire connection part 122, while leaving intact an ultrasonic junction surface 122a to which a core wire 111 is to be ultrasonically joined; a core wire installation step in which a core wire exposure part 111a is placed on the ultrasonic junction surface and the junction blocking part; and a joining step in which, while sandwiching and pressurizing the core wire junction part and the core wire exposure part with a first metal mold 21 and a second metal mold 22, the core wire exposure part is ultrasonically joined to at least the ultrasonic junction surface in the core wire junction part by ultrasonic vibration applied to the second metal mold. In the joining step, a first pressurized part 111b of the core wire exposure part ultrasonically joined to the ultrasonic junction surface and a second pressurized part 111c which is closer to a sheath 112 than the first pressurized part in the core wire exposure part and which is placed in the junction blocking part are pressurized by the second metal mold, and in the junction blocking part formation step, a junction blocking part is formed at a position of the core wire junction part at which the second pressurized part is placed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Conventionally, in manufacturing methods of electric wires with terminals, ultrasonic bonding is known as a technique for physically and electrically connecting an electric wire and a terminal fitting, in which ultrasonic vibrations are applied to an exposed core portion of the electric wire and a core joint portion of the terminal fitting while applying pressure. In this ultrasonic bonding, the exposed core portion and the core joint portion are sandwiched between two dies and pressure is applied, while ultrasonic vibrations are applied to the exposed core portion from one of the dies (vibration dies) in a vibration direction along the axial direction of the exposed core portion. The electric wire and the terminal fitting are ultrasonically bonded between the element wires of the exposed core portion and between the element wires of the exposed core portion and the core joint portion by the application of pressure and ultrasonic vibrations, thereby forming an electric wire with terminal. This type of electric wire with terminal is disclosed, for example, in Patent Documents 1 to 5 listed below. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-172927 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-107104 [Patent Document 3] Japanese Patent Application Laid-Open No. 2014-211952 [Patent Document 4] Japanese Patent Application Publication No. 2019-040778 [Patent Document 5] Japanese Patent Application Publication No. 2019-145263 Summary of the Invention [Problem to be solved by the invention]

[0004] In the exposed core portion of the electric wire, when ultrasonic vibrations are first applied from the vibration die, the wires in the exposed core portion and the wires in the exposed core portion and the wire joining portion have not yet begun to be joined, so there is no significant difference in the amount of relative movement in the vibration direction between these portions or between the wires in contact with the vibration die and the vibration die. However, in the exposed core portion, as joining between the wires and the wires and the wire joining portion progresses, the amount of relative movement in the vibration direction between them decreases. Meanwhile, in the exposed core portion, the amount of relative movement in the vibration direction between the wires in contact with the vibration die and the vibration die has not changed significantly since the start of ultrasonic joining. In other words, in this core wire exposed portion, as joining between the element wires or between the element wire and the core wire joining portion progresses, the amount of relative movement in the vibration direction between the element wire in contact with the core wire joining portion and the core wire joining portion decreases from the amount at the start of ultrasonic joining, but the amount of relative movement in the vibration direction between the element wire in contact with the vibration die and the vibration die remains the same as at the start of ultrasonic joining. Therefore, in this core wire exposed portion, as joining progresses and the difference in the amount of relative movement between the core wire joining portion side and the vibration die side increases, the load on the element wire on the vibration die side increases, which may cause the element wire to break.

[0005] Therefore, an object of the present invention is to provide a method for manufacturing an electric wire with a terminal that can suppress breakage of the wires during ultrasonic bonding. [Means for solving the problem]

[0006] The present invention includes a joint inhibiting portion forming step of forming a joint inhibiting portion that inhibits ultrasonic bonding in a core wire joining portion of a terminal fitting to which a core wire consisting of a wire bundle is ultrasonically joined while leaving an ultrasonic joining surface that is the target of ultrasonic bonding of the core wire; a core wire placing step of placing an exposed core wire portion, in which the core wire is covered with a coating and the core wire is exposed in the circumferential direction, on the ultrasonic joining surface and the joint inhibiting portion in the core wire joining portion; and a step of sandwiching and pressurizing the core wire joining portion and the exposed core wire portion between a first mold that is brought into contact with the core wire joining portion and a second mold that is brought into contact with the exposed core wire portion. and a joining step of ultrasonically joining the exposed core portion to at least the ultrasonic joining surface of the core joining portion by ultrasonic vibrations applied to the second mold while applying ultrasonic vibrations to the second mold, wherein in the joining step, a first pressure-receiving portion of the exposed core portion to be ultrasonically joined to the ultrasonic joining surface of the core joining portion and a second pressure-receiving portion at a portion of the exposed core portion closer to the coating than the first pressure-receiving portion and placed on the joining-inhibiting portion are pressed against the second mold, and in the joining-inhibiting portion forming step, a pressure-receiving portion is applied to the exposed core portion at a position where the second pressure-receiving portion was placed in the core joining step. The joining-inhibiting portion is made of plating applied to a part of the surface of the core wire joining portion, the joining-inhibiting portion is made of a non-metallic material provided on a part of the surface of the core wire joining portion, or the joining-inhibiting portion is made of an oxide film that modifies a part of the surface of the core wire joining portion. The bonding inhibiting portion is formed. [Effects of the Invention]

[0007] In the manufacturing method of an electric wire with a terminal according to the present invention, even if ultrasonic bonding between each of the wires from the first pressure-receiving portion to the second pressure-receiving portion or ultrasonic bonding between the wires of the first pressure-receiving portion and the ultrasonic bonding surface progresses during the joining process, the relative movement amount in the vibration direction of the ultrasonic vibration between the wires of the second pressure-receiving portion and the second die does not change significantly. Furthermore, even if ultrasonic bonding progresses during this joining process, because the wires on the core wire joining portion side of the second pressure-receiving portion are in contact with the joining-inhibiting portion, the relative movement amount in the vibration direction of the ultrasonic vibration between the wires on the core wire joining portion side of the second pressure-receiving portion and the joining-inhibiting portion does not change significantly or is unlikely to decrease. Therefore, even as ultrasonic bonding progresses during this joining process, the difference between the relative movement amount of the second pressure-receiving portion on the second die side and the relative movement amount of the second pressure-receiving portion on the core wire joining portion side does not easily widen. Therefore, in the core wire exposed portion, a large load is unlikely to be applied to the wires on the sheath side of the second pressure-receiving portion, making it less likely for the wires to break. In this way, the method for manufacturing an electric wire with terminal according to the present invention can prevent the occurrence of wire breakage during ultrasonic bonding. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is an explanatory diagram showing an ultrasonic joining machine according to an embodiment together with an electric wire with a terminal. [Figure 2] FIG. 2 is a plan view of the terminal fitting as seen from the ultrasonic bonding surface side. [Figure 3] FIG. 3 is a cross-sectional view taken along line XX in FIG. [Figure 4] FIG. 4 is an explanatory diagram showing a manufacturing apparatus according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for manufacturing an electric wire with a terminal according to the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to this embodiment.

[0010] [Embodiment] One embodiment of the method for manufacturing an electric wire with terminal according to the present invention will be described with reference to FIGS.

[0011] 1 indicates an electric wire with terminal of this embodiment. Here, the manufacturing apparatus 1 and the manufacturing method will be described in the description of the manufacturing apparatus 1 and the electric wire with terminal 101 produced by the manufacturing method using the manufacturing apparatus 1, which will be described later.

[0012] The electric wire with terminal 101 includes an electric wire 110 and a terminal fitting 120 that are physically and electrically connected to each other (FIG. 1).

[0013] The electric wire 110 has a core wire 111 and a covering 112, and the core wire 111 is covered from the outer periphery side with a tubular covering 112 (Fig. 1). The core wire 111 is configured as a wire bundle in which a plurality of wires 113 made of conductive metal wire are bundled together. The covering 112 is molded from an insulating synthetic resin material and covers the core wire 111 from the outer periphery side.

[0014] The electric wire 110 has an exposed core portion 111a that is exposed in the circumferential direction (FIG. 1). For example, the electric wire 110 is provided with the exposed core portion 111a that is exposed around the entire circumference at its end (hereinafter referred to as the "electric wire end") 110a by processing the coating 112, such as by stripping off an end of the coating 112 in the circumferential direction. The exposed core portion 111a of the electric wire end 110a protrudes from the annular end face of the coating 112, and a location of the coating 112 that is spaced from the end face toward the free end is ultrasonically joined to the terminal fitting 120. Also, for example, the electric wire 110 is provided with the exposed core portion 111a that is exposed around the entire circumference between two annular end faces of the coating 112 by stripping off the coating 112 in the circumferential direction at the midpoint of the axis of the electric wire 110. The exposed core portion 111a of the electric wire 110 is ultrasonically joined to the terminal fitting 120 at a location between two end faces of the coating 112 and spaced apart from each end face.

[0015] In this electric wire with terminal 101, a terminal fitting 120 is attached to an exposed core portion 111a at the end or midway of the electric wire 110. The electric wire 110 shown here has an exposed core portion 111a at the electric wire end 110a. Therefore, in this electric wire with terminal 101, the terminal fitting 120 is attached to the exposed core portion 111a of the electric wire end 110a.

[0016] The terminal fitting 120 is made of a conductive material such as metal, and is formed into a predetermined shape by, for example, press forming such as bending or cutting a metal plate as a base material.

[0017] This terminal fitting 120 has a terminal connection portion 121 for physically and electrically connecting to a mating part (not shown) (FIGS. 1 to 3). This terminal connection portion 121 may be physically and electrically connected to the mating part in any form. The terminal connection portion 121 shown here is formed in a flat plate shape with a through hole 121a (FIG. 2). This terminal connection portion 121 is fixed to the terminal connection portion of the mating terminal fitting by, for example, screwing a female screw member into a male screw member inserted through the through hole 121a and the through hole of the terminal connection portion (not shown) of the mating terminal fitting. Also, for example, one of the terminal connection portion 121 of the terminal fitting 120 and the terminal connection portion of the mating terminal fitting may be formed in a female terminal shape and the other in a male terminal shape, and they may be inserted and fitted together.

[0018] The terminal fitting 120 also has a core wire joining portion 122 to which the core wire 111 of the electric wire 110 is ultrasonically joined (FIGS. 1 to 3). The core wire joining portion 122 is formed in a flat plate shape. The core wire joining portion 122 shown here is formed in a rectangular flat plate shape. The exposed core wire portion 111a of the electric wire 110 is placed on one flat surface of the core wire joining portion 122 and ultrasonically joined.

[0019] This terminal fitting 120 is formed as a single flat piece consisting of the terminal connection portion 121 and the core wire joining portion 122, but it may be formed into any shape, for example, into a cross shape bent toward the terminal connection portion 121 side and the core wire joining portion 122 side.

[0020] Here, in order to prevent wire breakage when ultrasonically joining the exposed core wire portion 111a of the electric wire 110 and the core wire joining portion 122 of the terminal fitting 120, a joining-inhibiting portion 122b (FIGS. 1 to 3) described below is provided in advance in the core wire joining portion 122, and then the exposed core wire portion 111a is ultrasonically joined to the core wire joining portion 122. For this reason, the manufacturing method of the electric wire with terminal 101 includes a joining-inhibiting portion forming step of forming the joining-inhibiting portion 122b in the core wire joining portion 122, a core wire placing step of placing the exposed core wire portion 111a on the core wire joining portion 122, and a joining step of ultrasonically joining the exposed core wire portion 111a and the core wire joining portion 122. The manufacturing apparatus 1 of the electric wire with terminal 101 includes a joining-inhibiting portion forming machine 10 for performing the joining-inhibiting portion forming step, and an ultrasonic joining machine 20 for performing the core wire placing step and the joining step (FIG. 4). For convenience of illustration, the bonding-inhibiting portion 122b in the drawing is shown by cross-hatching with its size exaggerated.

[0021] In the joining-inhibiting portion forming process, a joining-inhibiting portion 122b that acts as an obstruction to ultrasonic joining is formed in a portion of the core wire joining portion 122 of the terminal fitting 120, while leaving the ultrasonic joining surface 122a that is the target of ultrasonic joining of the core wire 111 (Figures 1 to 4).

[0022] The ultrasonic bonding surface 122a is a wall surface that ultrasonically bonds the exposed core portion 111a, and exists on one plane of the core bonding portion 122. In the core bonding portion 122, the exposed core portion 111a is ultrasonically bonded to at least the ultrasonic bonding surface 122a.

[0023] The joining-inhibiting portion 122b is a portion for reducing the frictional force between a part of the core wire joining portion 122 and the wires 113 when ultrasonic vibration is applied to the exposed core wire portion 111a, and is provided on part of the surface of the core wire joining portion 122 and is interposed between the exposed core wire portion 111a and the core wire joining portion 122 during ultrasonic joining. The joining-inhibiting portion 122b is provided on the same plane as the ultrasonic joining surface 122a of the core wire joining portion 122 (i.e., on one plane of the core wire joining portion 122 where the ultrasonic joining surface 122a is present). The exposed core wire portion 111a ultrasonically joins the wires 113 to the ultrasonic joining surface 122a of the core wire joining portion 122, but the ultrasonic joining of the wires 113 is inhibited at part of the surface of the core wire joining portion 122 where the joining-inhibiting portion 122b is present (hereinafter referred to as the "joining-inhibiting surface"). For example, depending on its shape and the application time of the ultrasonic vibration, the bonding-inhibiting portion 122b may prevent the core wire exposed portion 111a from being ultrasonically bonded to the bonding-inhibiting surface, or may delay the time until the core wire exposed portion 111a starts to be ultrasonically bonded to the bonding-inhibiting surface compared to the time until the core wire exposed portion 111a starts to be ultrasonically bonded to the ultrasonic bonding surface 122a.

[0024] The bonding-inhibiting portion 122b may be any portion that inhibits ultrasonic bonding of the exposed core wire portion 111a. For example, it may be the following.

[0025] The bonding-inhibiting portion 122b may be a plating (soft plating) applied to a portion of the surface (bonding-inhibiting surface) of the core wire bonding portion 122. For example, stripe-shaped tin plating is applied to the portion of the surface (bonding-inhibiting surface) of the core wire bonding portion 122. In this case, a plating generating device is used as the bonding-inhibiting portion forming machine 10. Note that although it does not matter whether the surface of the terminal fitting 120 is plated or not, if the entire surface of the terminal fitting 120 is plated, it is desirable that the plating used for the bonding-inhibiting portion 122b be more difficult to ultrasonically bond than the plating of other portions.

[0026] The bonding-inhibiting portion 122b may be a non-metallic material (oil, synthetic resin, etc.) provided on a portion of the surface (bonding-inhibiting surface) of the core wire bonding portion 122. For example, an oil film is formed on the portion of the surface (bonding-inhibiting surface) of the core wire bonding portion 122 using a quick-drying oil-based ink or the like. In this case, the bonding-inhibiting portion forming machine 10 may be, for example, an oil-based ink applicator. When a non-quick-drying oil is used, the oil is filled into a recess in the portion of the surface (bonding-inhibiting surface) of the core wire bonding portion 122 to create an oil reservoir on the surface. For example, the recess may be formed by utilizing the unevenness of the original surface roughness of the portion of the surface (bonding-inhibiting surface) of the core wire bonding portion 122, or by utilizing multiple unevenness formed by processing the portion of the surface (bonding-inhibiting surface) of the core wire bonding portion 122. In this case, the bonding-inhibiting portion forming machine 10 may be, for example, a roughness processing device and an oil filling device.

[0027] The bonding-inhibiting portion 122b may be an oxide film formed by modifying a portion of the surface (bonding-inhibiting surface) of the core wire bonding portion 122. For example, a laser may be irradiated onto the portion of the surface (bonding-inhibiting surface) of the core wire bonding portion 122 to modify this portion and form an oxide film. In this case, a laser irradiation device is used as the bonding-inhibiting portion forming machine 10.

[0028] In the bonding-inhibiting portion forming process, a bonding-inhibiting portion 122b may be formed which is made of plating applied to a portion of the surface (bonding-inhibiting surface) of the core wire bonding portion 122, a bonding-inhibiting portion 122b made of a non-metallic material provided on a portion of the surface (bonding-inhibiting surface) of the core wire bonding portion 122, or a bonding-inhibiting portion 122b made of an oxide coating which has been modified on a portion of the surface (bonding-inhibiting surface) of the core wire bonding portion 122.

[0029] In this terminal fitting 120, the exposed core wire portion 111a is ultrasonically bonded to the core wire joining portion 122 having any of the joining inhibiting portions 122b formed therein. Therefore, in the core wire installation step, the exposed core wire portion 111a is placed on the ultrasonic joining surface 122a and the joining inhibiting portion 122b of the core wire joining portion 122. Then, the exposed core wire portion 111a and the core wire joining portion 122 are ultrasonically bonded in the joining step.

[0030] The ultrasonic bonding machine 20 shown here includes a first mold 21 and a second mold 22 that sandwich and pressurize the core wire exposed portion 111a and the core wire bonding portion 122 while applying ultrasonic vibrations to the core wire exposed portion 111a and the core wire bonding portion 122 (Figure 1).

[0031] The core wire joining portion 122 of the terminal fitting 120 is placed on a first mold 21. Therefore, in the core wire installation step, the exposed core portion 111a is placed on one flat surface of the core wire joining portion 122 placed on this first mold 21. The first mold 21 shown here has a contact portion 21a consisting of a plurality of concaves and convexes, and the other flat surface of the core wire joining portion 122 is placed on this contact portion 21a (FIG. 1). The contact portion 21a is, for example, a plurality of concaves and convexes formed by knurling applied to the first mold 21.

[0032] The second mold 22 is a mold that can move back and forth, moving toward and away from the first mold 21, and is attached to a drive unit (not shown) that performs this reciprocating movement. When the second mold 22 is brought closer to the first mold 21, it comes into contact with the exposed core portion 111a above the core joining portion 122, and pressurizes the exposed core portion 111a and the core joining portion 122 between itself and the first mold 21. The second mold 22 shown here has a contact portion 22a similar to the contact portion 21a of the first mold 21, and this contact portion 22a is brought into contact with the exposed core portion 111a (FIG. 1).

[0033] In the bonding process, the core wire bonding portion 122 and the core wire exposed portion 111a are sandwiched and pressurized between a first mold 21 in contact with the core wire bonding portion 122 and a second mold 22 in contact with the core wire exposed portion 111a, and ultrasonic vibrations are applied to the second mold 22 to ultrasonically bond the core wire exposed portion 111a to at least the ultrasonic bonding surface 122a of the core wire bonding portion 122. The ultrasonic bonding machine 20 includes an ultrasonic oscillator (not shown), and applies ultrasonic vibrations from this ultrasonic oscillator to the second mold 22.

[0034] Specifically, in this joining step, the first pressure-receiving portion 111b of the core wire exposed portion 111a to be ultrasonically joined to the ultrasonic joining surface 122a of the core wire joining portion 122, and the second pressure-receiving portion 111c, which is a portion of the core wire exposed portion 111a closer to the coating 112 than the first pressure-receiving portion 111b and which is placed on the joining-inhibiting portion 122b, are pressed against the second mold 22 (FIG. 1). Therefore, in the core wire installation step, when placing the core wire exposed portion 111a on the core wire joining portion 122 placed on the first mold 21, the first pressure-receiving portion 111b of the core wire exposed portion 111a is placed on the ultrasonic joining surface 122a, and the second pressure-receiving portion 111c of the core wire exposed portion 111a is placed on the joining-inhibiting portion 122b. Therefore, in the joining-inhibiting portion forming step, the joining-inhibiting portion 122b is formed in the core wire joining portion 122 at a position where the second pressure-receiving portion 111c is placed in the core wire setting step.

[0035] In the joining step, the second mold 22 is brought into contact with the first pressure-receiving portion 111b and the second pressure-receiving portion 111c while being brought closer to the first mold 21, but the second mold 22 is not brought into contact with the remaining portion of the core wire exposed portion 111a (at least the portion between the second pressure-receiving portion 111c and the annular end face of the coating 112) (FIG. 1). Also, in this joining step, the first pressure-receiving portion 111b of the core wire exposed portion 111a is in contact with the ultrasonic joining surface 122a, while the joining-inhibiting portion 122b is interposed between the second pressure-receiving portion 111c of the core wire exposed portion 111a and the joining-inhibiting surface of the core wire joining portion 122 (FIG. 1).

[0036] Therefore, in this joining process, the wires 113 from the first pressure-receiving portion 111b to the second pressure-receiving portion 111c in the exposed core portion 111a move relative to one another in the vibration direction of the ultrasonic vibrations, causing friction between the wires 113, and oxide films or the like are destroyed on the surfaces of the wires 113 where this friction is occurring, causing new surfaces to appear on the surface. Then, in this joining process, adhesion nuclei are generated at locations where the new surfaces of the wires 113 from the first pressure-receiving portion 111b to the second pressure-receiving portion 111c come into contact with each other, and from these adhesion nuclei, the welding area expands and the joining between the wires 113 progresses. Furthermore, during this joining process, at the same timing as the ultrasonic joining of the wires, the wires 113 of the first pressure-receiving portion 111b in the exposed core portion 111a and the ultrasonic joining surface 122a move relative to each other in the vibration direction of the ultrasonic vibrations, causing friction between the wires 113 of the first pressure-receiving portion 111b and the ultrasonic joining surface 122a, and oxide films or the like are destroyed on the surfaces of the wires 113 of the first pressure-receiving portion 111b and the ultrasonic joining surface 122a where this friction occurs, exposing new surfaces. During this joining process, adhesion nuclei are generated at the locations where the newly formed surfaces contact between the wires 113 of the first pressure-receiving portion 111b and the ultrasonic joining surface 122a, and the welding area expands from these adhesion nuclei, thereby progressing the joining between the wires 113 of the first pressure-receiving portion 111b and the ultrasonic joining surface 122a.

[0037] In this joining process, as ultrasonic bonding progresses between the wires 113 of the first pressure-receiving portion 111b to the second pressure-receiving portion 111c, the amount of relative movement in the vibration direction of the ultrasonic vibration between the wires 113 decreases. Furthermore, in this joining process, as ultrasonic bonding progresses between the wires 113 of the first pressure-receiving portion 111b and the ultrasonic bonding surface 122a, the amount of relative movement in the vibration direction of the ultrasonic vibration between the wires 113 of the first pressure-receiving portion 111b and the ultrasonic bonding surface 122a decreases. On the other hand, in this joining process, even if ultrasonic bonding progresses, the amount of relative movement in the vibration direction of the ultrasonic vibration between the wires 113 of the first pressure-receiving portion 111b and the second mold 22 does not change significantly. For this reason, in this joining process, although the amount of movement of the wire 113 on the ultrasonic joining surface 122a side of the first pressure-receiving portion 111b relative to the ultrasonic joining surface 122a in the vibration direction decreases as the ultrasonic joining proceeds, the amount of movement of the wire 113 on the second mold 22 side of the first pressure-receiving portion 111b remains large relative to the second mold 22 in the vibration direction. However, in the core wire exposed portion 111a, the first pressure-receiving portion 111b is sandwiched between the free end side and the second pressure-receiving portion 111c, and a large load is unlikely to be applied to the wire 113 on the second mold 22 side between the free end side of the first pressure-receiving portion 111b and the second pressure-receiving portion 111c side, so that the wire 113 is unlikely to break.

[0038] Furthermore, in this joining process, even if ultrasonic bonding progresses between the respective element wires 113 from the first pressure-receiving portion 111b to the second pressure-receiving portion 111c and between the element wires 113 of the first pressure-receiving portion 111b and the ultrasonic bonding surface 122a, the amount of relative movement in the vibration direction of ultrasonic vibration between the element wires 113 of the second pressure-receiving portion 111c and the second mold 22 does not change much, just as with the second mold 22 side of the first pressure-receiving portion 111b. Furthermore, in this joining process, even if ultrasonic bonding progresses, the element wires 113 on the core wire bonding portion 122 side of the second pressure-receiving portion 111c are in contact with the bonding inhibition portion 122b, so the amount of relative movement in the vibration direction of ultrasonic vibration between the element wires 113 on the core wire bonding portion 122 side of the second pressure-receiving portion 111c and the bonding inhibition portion 122b (the bonding inhibition surface of the core wire bonding portion 122) does not change much, or the amount of relative movement is unlikely to decrease. For this reason, in this joining step, even as the ultrasonic joining progresses, the difference between the amount of relative movement of the second pressure-receiving portion 111c on the second mold 22 side (the amount of relative movement in the vibration direction of the wires 113 on the second mold 22 side of the second pressure-receiving portion 111c with respect to the second mold 22) and the amount of relative movement of the second pressure-receiving portion 111c on the core wire joining portion 122 side (the amount of relative movement in the vibration direction of the wires 113 on the core wire joining portion 122 side of the second pressure-receiving portion 111c with respect to the core wire joining portion 122) is unlikely to widen. Therefore, in the core wire exposed portion 111a, a large load is unlikely to be applied to the wires 113 between the first pressure-receiving portion 111b side and the coating 112 side of the second pressure-receiving portion 111c, and therefore, the wires 113 are unlikely to break.

[0039] In this way, by using the manufacturing method of the electric wire with terminal 101 of this embodiment, it is possible to prevent the occurrence of wire breakage during ultrasonic bonding.

[0040] Furthermore, the manufacturing method for the electric wire with terminal 101 of this embodiment simply involves providing the joining inhibiting portion 122b to the core wire joining portion 122 after forming the terminal fitting 120, and does not require any particular changes to the shapes of the terminal fitting 120 or the electric wire 110. Furthermore, this manufacturing method does not require any changes to the structure of the manufacturing apparatus 1. Therefore, the manufacturing method for the electric wire with terminal 101 of this embodiment can easily and inexpensively obtain the effect of suppressing wire breakage during ultrasonic joining. [Explanation of symbols]

[0041] 21 First mold 22 Second mold 101 Wire with terminal 110 Electric wire 111 Core wire 111a exposed core 111b 1st pressurized part 111c 2nd pressurized part 112 Covering 113 Wire 120 Terminal fittings 122 Core joint 122a Ultrasonic bonding surface 122b Junction inhibitor

Claims

[Claim 1] a joining inhibiting portion forming step of forming a joining inhibiting portion that inhibits ultrasonic joining at a core wire joining portion of the terminal fitting to which a core wire made of a wire bundle is to be ultrasonically joined, while leaving an ultrasonic joining surface that is to be ultrasonically joined to the core wire; a core wire installation process of placing an exposed core wire portion, in which the core wire is covered with a coating and exposed in a circumferential direction of the electric wire, on the ultrasonic joining surface and the joining inhibiting portion of the core wire joining portion; a joining process in which the core wire joining portion and the core wire exposed portion are sandwiched and pressurized between a first mold in contact with the core wire joining portion and a second mold in contact with the core wire exposed portion, and ultrasonically joining the core wire exposed portion to at least the ultrasonic joining surface of the core wire joining portion by ultrasonic vibrations applied to the second mold; and In the joining step, a first pressure-applied portion of the core wire exposed portion to be ultrasonically joined to the ultrasonic joining surface of the core wire joining portion and a second pressure-applied portion located on the coating side of the core wire exposed portion relative to the first pressure-applied portion and placed on the joining-inhibiting portion are pressed against the second mold, A method for manufacturing an electric wire with a terminal, characterized in that in the joining-inhibiting portion forming process, the joining-inhibiting portion is formed at the core wire joining portion at a position where the second pressurized portion is placed in the core wire installing process, the joining-inhibiting portion being made of plating applied to a portion of the surface of the core wire joining portion, the joining-inhibiting portion being made of a non-metallic material provided on a portion of the surface of the core wire joining portion, or the joining-inhibiting portion being made of an oxide coating that modifies a portion of the surface of the core wire joining portion.

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