Method for manufacturing electric wire with terminal

Abstract

To provide a manufacturing method of an electric wire with a terminal capable of joining a terminal and a conductor of the electric wire with high strength in a short time, in the manufacturing method of the electric wire with the terminal for joining the conductor of the electric wire and the terminal by ultrasonic joining.SOLUTION: A method for manufacturing a terminal-equipped electric wire including an electric wire having a conductor formed of a plurality of metal strands and a terminal to which the conductor is joined, the method comprising: And a step B of placing the conductor of the electric wire on the terminal with which the slide suppressing jig is in contact, pressing the horn against the conductor of the electric wire, and connecting the conductor and the terminal by ultrasonic welding, wherein in the step A, the terminal and the slide suppressing jig are brought into contact with each other in a state of being engaged and fixed.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Power supplies and electrical equipment mounted on vehicles such as automobiles are usually connected to one another by a wire harness consisting of a plurality of electric wires with terminals. The plurality of electric wires with terminals that make up this wire harness are configured such that, for example, conductors exposed from an insulating coating are joined to terminals.

[0003] Conventionally, various methods have been proposed for joining a conductor and a terminal, one example of which is a joining method using ultrasonic vibrations with a horn and anvil (that is, ultrasonic joining) (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-188373 Summary of the Invention [Problem to be solved by the invention]

[0005] In joining the wire (conductor) and terminal of the above-mentioned terminal-attached electric wire, vibrations transmitted from the horn are transmitted through the wire to the contact interface with the terminal, and the metal-to-metal vibrations create a metallic bond, joining the conductor and terminal. The terminal's movement is controlled by pressing it against a protrusion on the anvil with a gliding jaw or by the load transmitted from the horn. However, if the load or vibration transmitted from the horn is greater than the force required to secure the terminal, the terminal will move with the wire, resulting in a reduction in the energy required for the metallic bond. As a result, the bond strength between the wire conductor and terminal is reduced and the joining process takes a long time.

[0006] The present invention has been made in view of the problems inherent in the prior art, and an object of the present invention is to provide a method for manufacturing an electric wire with a terminal, in which the conductor of the electric wire and the terminal are joined by ultrasonic bonding, and the method can join the terminal and the conductor of the electric wire with high strength in a short time. [Means for solving the problem]

[0007] A manufacturing method of an electric wire with a terminal according to an embodiment of the present invention is a manufacturing method of an electric wire with a terminal having an electric wire having a conductor made of a plurality of metal wires and a terminal to which the conductor is joined, and includes: step A of abutting a sliding prevention jig that prevents the terminal from sliding against the terminal placed on the anvil of an ultrasonic joining machine; and step B of placing the conductor of the electric wire on the terminal against which the sliding prevention jig is abutted, pressing a horn against the conductor of the electric wire, and connecting the conductor and the terminal by ultrasonic welding; in step A, the terminal and the sliding prevention jig are abutted in an engaged and fixed state. [Effects of the Invention]

[0008] According to the present invention, in a manufacturing method of an electric wire with a terminal in which the conductor of the electric wire and the terminal are joined by ultrasonic joining, it is possible to provide a manufacturing method of an electric wire with a terminal in which the joining of the terminal and the conductor of the electric wire can be performed in a short time with high strength. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view showing an electric wire with a terminal according to an embodiment of the present invention; [Figure 2] 3 is a conceptual diagram showing how a conductor of an electric wire is joined to a terminal in the first embodiment. FIG. [Figure 3] 3 is an exploded side view showing the slide-preventing jig, the terminal, and the anvil in the first embodiment. FIG. [Figure 4] 10 is a side view showing a state in which the slide-preventing jig, the terminal, and the anvil are in contact with each other in the first embodiment. FIG. [Figure 5] 10 is a side view showing a state in which the inclined surfaces of the sliding prevention jig and the terminal are engaged with each other in the first embodiment. FIG. [Figure 6] FIG. 10 is a top view showing an arrangement when joining a conductor of an electric wire to a terminal in a second embodiment. [Figure 7] FIG. 10 is a side view showing how a conductor of an electric wire is joined to a terminal in the second embodiment. [Figure 8] FIG. 10 is an exploded side view showing the slide-preventing jig, the terminal, and the anvil in the second embodiment. [Figure 9] FIG. 10 is a side view showing a state in which the slide-preventing jig, the terminal, and the anvil are in contact with each other in the second embodiment. [Figure 10] 10 is a side view showing a state in which the inclined surfaces of the sliding prevention jig and the terminal are engaged with each other in the second embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, the manufacturing method of the electric wire with terminal according to the present embodiment will be described in detail with reference to the drawings. Note that the dimensional proportions in the drawings are exaggerated for the convenience of explanation and may differ from the actual proportions.

[0011] The method for manufacturing an electric wire with terminal of this embodiment is a method for manufacturing an electric wire with a terminal having a conductor made of a plurality of metal wires and a terminal to which the conductor is joined. The method for manufacturing an electric wire with terminal includes a step A of bringing a sliding prevention jig that prevents sliding of the terminal into contact with the terminal placed on the anvil of an ultrasonic joining machine. The method for manufacturing an electric wire with terminal also includes a step B of placing the conductor of the electric wire on the terminal to which the sliding prevention jig is contacted, pressing a horn against the conductor of the electric wire, and connecting the conductor and the terminal by ultrasonic welding. In step A, the terminal and the sliding prevention jig are brought into contact in an engaged and fixed state.

[0012] As described above, if the load and vibration transmitted from the horn are greater than the force fixing the terminal, the terminal will displace in response to the movement of the electric wire, reducing the energy required for metal bonding. In contrast, in the method for manufacturing an electric wire with terminal of this embodiment, the terminal and the sliding prevention jig abut in an engaged and fixed state, increasing the fixing force of the terminal and preventing the terminal from moving in response to the movement of the electric wire. As a result, the terminal and the conductor of the electric wire can be joined in a short time with high joining strength.

[0013] In the manufacturing method of an electric wire with terminal of this embodiment, there are two specific embodiments for abutting the terminal and the sliding prevention jig in an engaged and fixed state in step A. One is a embodiment in which a recess is formed in the terminal and the sliding prevention jig is engaged with the recess, and the other is a embodiment in which a recess is formed in the sliding prevention jig and a flange formed on the terminal is engaged with the recess. The sliding prevention jig is an improved gliding jaw. Below, the former will be described as the first embodiment, and the latter will be described as the second embodiment.

[0014] [First form] In the first embodiment, the sliding prevention jig has a pair of inclined surfaces formed on both ends in the longitudinal direction of the electric wire. In addition, the sliding prevention jig has a recess formed in the sliding prevention jig where the terminal abuts against the sliding prevention jig, into which the sliding prevention jig fits, and a pair of inclined surfaces that engage with the pair of inclined surfaces of the sliding prevention jig are formed on both ends of the recess in the longitudinal direction of the electric wire. The following description will be made with reference to the drawings.

[0015] FIG. 1 shows an electric wire with terminal 10 manufactured by the manufacturing method of an electric wire with terminal of the first embodiment. The electric wire with terminal 10 shown in FIG. 1 includes an electric wire 12 and a terminal 14. The electric wire 12 includes a conductor 16 made of a plurality of metal wires and a covering 18 covering the conductor 16. The conductor 16 is formed by twisting together a plurality of wires made of, for example, aluminum or an aluminum alloy, but may be formed of other materials (e.g., copper or a copper alloy). The terminal 14 is formed of, for example, copper or a copper alloy, but is not limited to any metal material as long as it is conductive. The electric wire with terminal 10 is particularly suitable for use in vehicles that frequently use wire harnesses, such as electric vehicles and hybrid vehicles. In FIG. 1, an end of the conductor 16 is not covered by the covering 18 and is exposed. The conductor 16 is joined to the terminal 14 by ultrasonic welding. Furthermore, the terminal 14 is formed with a recess 14A and a pair of inclined surfaces 14B and 14C, which are formed during ultrasonic bonding, as will be described below.

[0016] FIG. 2 shows how the conductor 16 of the electric wire 12 is joined to the terminal 14 by ultrasonic welding. Specifically, a sliding prevention jig 24 that prevents sliding of the terminal 14 is brought into contact with the terminal 14 placed on the anvil 20 of an ultrasonic welding machine. The conductor 16 of the electric wire 12 is then placed on the terminal 14 against which the sliding prevention jig 24 is brought into contact, and a horn 22 is pressed against the conductor 16 of the electric wire 12, thereby connecting the conductor 16 to the terminal 14 by ultrasonic welding. In other words, FIG. 2 shows how step B is performed after step A is performed. As shown in FIG. 2, a recess 14A is formed in the terminal 14, and the lower end of the sliding prevention jig 24 is fitted into the recess 14A. More specifically, as shown in FIG. 3, the sliding prevention jig 24 has a pair of inclined surfaces 24A, 24B formed at both ends in the longitudinal direction of the electric wire 12. A recess 14A into which the slide-preventing jig 24 fits is formed at the contact point of the terminal 14 with the slide-preventing jig 24. Additionally, a pair of inclined surfaces 14B, 14C are formed at both ends of the recess 14A in the longitudinal direction of the wire 12, which engage with the pair of inclined surfaces 24A, 24B of the slide-preventing jig 24. When the recess 14A of the terminal 14 is brought into contact with the slide-preventing jig 24, as shown in FIG. 4, the pair of inclined surfaces 14B, 14C formed on each of the recess 14A and the slide-preventing jig 24 engage with the inclined surfaces 24A, 24B. The upper surface of the anvil 20 and the lower surface of the horn 22 may be roughened as needed, and the zigzag lines in FIGS. 1 to 5 indicate such roughened surfaces. In this state, the terminal 14 is subjected to vibration transmitted from the horn 22 in the direction of the arrow X.

[0017] As described above, the sliding prevention jig 24 fits into the recess 14A of the terminal 14. The degree of fitting does not necessarily require that the surface of the recess 14A of the terminal 14 and the lower surface of the sliding prevention jig 24 abut against each other. As shown in FIGS. 2, 4, and 5, there may be a gap between the surface of the recess 14A of the terminal 14 and the lower surface of the sliding prevention jig 24. In short, it is important that the pair of inclined surfaces 14B, 14C formed on the recess 14A of the terminal 14 and the pair of inclined surfaces 24A, 24B, respectively, are firmly engaged with each other. The shape of the sliding prevention jig 24 is not particularly limited as long as it functions to position the conductor 16 of the wire 12, fits into the recess 14A of the terminal 14, and can engage with the pair of inclined surfaces 14B, 14C.

[0018] FIG. 5 shows an enlarged view of the state in which inclined surface 14C and inclined surface 24B are engaged. Consider a situation in which terminal 14 attempts to displace in the direction of arrow A due to vibration transmitted from horn 22. When terminal 14 attempts to displace in the direction of arrow A, a resultant force in the direction of arrow B is generated due to the presence of a pair of inclined surfaces 14B, 14C and inclined surfaces 24A, 24B formed on recess 14A of terminal 14 and slide-preventing jig 24, respectively, which are engaged with each other. The resultant force in the direction of arrow B is broken down into forces in the directions of arrows B1 and B2. Of these, the force in the direction of arrow B2 presses terminal 14 against anvil 20. Therefore, when terminal 14 attempts to displace in the direction of arrow A, terminal 14 is pressed against anvil 20. As a result, terminal 14 is firmly fixed to anvil 20. Furthermore, since an inclined surface that suppresses movement following the electric wire 12 is provided on the surface where the terminal 14 and the slide-preventing jig 24 come into contact, displacement of the terminal 14 can be further suppressed.

[0019] As described above, the manufacturing method of the electric wire with terminal 10 of the first embodiment prevents a reduction in the energy required for metal bonding because the terminal 14 is firmly fixed, even when large vibrations are transmitted from the horn 22. Consequently, the terminal 14 and the conductor 16 of the electric wire 12 can be joined with high strength in a short time.

[0020] [Second form] In the second embodiment, the terminal is formed with a flange portion having a pair of inclined surfaces at both ends in the longitudinal direction of the wire at the contact point with the sliding prevention jig. Also, a recess is formed at the contact point of the sliding prevention jig with the terminal, which fits with the flange portion of the terminal. In addition, a pair of inclined surfaces is formed at both ends in the longitudinal direction of the wire of the recess, which engage with the pair of inclined surfaces of the flange portion of the terminal. The following description will be made with reference to the drawings.

[0021] Fig. 6 shows the arrangement when joining the terminal 14 and the conductor 16 of the electric wire 12 in the manufacturing method of the electric wire with terminal 10 of the second embodiment. In Fig. 6, elements that are substantially the same as elements in the drawings shown in the manufacturing method of the electric wire with terminal 10 according to the first embodiment are given the same reference numerals, and the explanation of these elements is the same as that in the first embodiment (the same applies to Figs. 7 and 8). As shown in Fig. 6, in the second embodiment, the terminal 14 is formed with a flange portion 15 that fits into a recess 25A of a sliding prevention jig 25 in a direction perpendicular to the longitudinal direction of the electric wire 12. For convenience of explanation, the sliding prevention jig 25 is omitted from Fig. 6.

[0022] FIG. 7 shows how the conductor 16 of the electric wire 12 is joined to the terminal 14 by ultrasonic welding. More specifically, a sliding prevention jig 25 that prevents sliding of the terminal 14 is brought into contact with the terminal 14 placed on the anvil 20 of an ultrasonic welding machine. The conductor 16 of the electric wire 12 is then placed on the terminal 14 against which the sliding prevention jig 25 is brought into contact, and a horn 22 is pressed against the conductor 16 of the electric wire 12, thereby connecting the conductor 16 to the terminal 14 by ultrasonic welding. As described above, the terminal 14 has a flange portion 15 formed in a direction perpendicular to the longitudinal direction of the electric wire 12, and the flange portion 15 is fitted into and brought into contact with the recess 25A of the sliding prevention jig 25. In other words, FIG. 7 shows how step B is carried out after step A is carried out. Furthermore, as shown in FIG. 8, the flange portion 15 of the terminal 14 has a pair of inclined surfaces 15A and 15B formed at both ends in the longitudinal direction of the electric wire 12. Furthermore, a recess 25A into which the flange 15 of the terminal 14 fits is formed in the contact area of ​​the slide-preventing jig 25 with the flange 15 of the terminal 14. Additionally, a pair of inclined surfaces 25B, 25C are formed at both ends of the recess 25A in the longitudinal direction of the wire 12, which engage with the pair of inclined surfaces 15A, 15B of the flange 15 of the terminal 14. When the flange 15 of the terminal 14 is brought into contact with the recess 25A of the slide-preventing jig 25, the pair of inclined surfaces 15A, 15B engage with the inclined surfaces 25B, 25C formed on the respective surfaces, as shown in FIG. 9 . As in the first embodiment, the upper surface of the anvil 20 and the lower surface of the horn 22 may be roughened as needed, and the zigzag lines in FIGS. 7 to 10 indicate such roughened surfaces. In this state, vibrations are applied in the direction of the arrow X transmitted from the horn 22.

[0023] As described above, the flange portion 15 of the terminal 14 fits into the recess 25A of the slide-preventing jig 25. The degree of fit does not necessarily require that the surface of the recess 25A of the slide-preventing jig 25 and the underside of the flange portion 15 of the terminal 14 abut against each other. For example, as shown in FIGS. 7, 9, and 10, there may be a gap between the surface of the recess 25A of the slide-preventing jig 25 and the underside of the flange portion 15 of the terminal 14. In short, it is important that the pair of inclined surfaces 25B, 25C formed on the recess 25A of the slide-preventing jig 25 and the flange portion 15 of the terminal 14, respectively, are firmly engaged with the pair of inclined surfaces 15A, 15B. The shape of the slide-preventing jig 25 is not particularly limited as long as it functions to position the conductor 16 of the wire 12, has a recess 25A into which the flange 15 formed on the terminal 14 fits, and is a shape that allows the flange 15 to fit into the recess 25A and engage with the pair of inclined surfaces 15A and 14B. Similarly, the shape of the flange 15 formed on the terminal 14 is not particularly limited as long as it is a shape that allows the flange 15 to fit into the slide-preventing jig 25 and engage with the pair of inclined surfaces 25B and 25C.

[0024] FIG. 10 shows an enlarged view of the engagement between inclined surface 25C and inclined surface 15B. Consider a situation in which terminal 14 attempts to displace in the direction of arrow B due to vibration transmitted from horn 22. When terminal 14 attempts to displace in the direction of arrow B, a resultant force in the direction of arrow B is generated due to the presence of a pair of inclined surfaces 15A, 15B and 25B, 25C, which are formed on flange portion 15 of terminal 14 and recess 25A of slide-preventing jig 25, respectively, and which are engaged with each other. The resultant force in the direction of arrow B is broken down into forces in the directions of arrows B1 and B2. Of these, the force in the direction of arrow B2 presses terminal 14 against anvil 20. Therefore, when terminal 14 attempts to displace in the direction of arrow B, terminal 14 is pressed against anvil 20. As a result, terminal 14 is firmly fixed to anvil 20. In addition, the force of vibration transmitted from horn 22 is offset by the presence of the inclined surface located on the opposite side, suppressing displacement of terminal 14. Furthermore, since the surface where terminal 14 and sliding prevention jig 25 come into contact is provided with a surface that suppresses movement following wire 12, displacement of terminal 14 can be further suppressed.

[0025] As described above, the manufacturing method of the electric wire with terminal 10 of the second embodiment prevents a reduction in the energy required for metal bonding because the terminal 14 is firmly fixed, even when large vibrations are transmitted from the horn 22. Consequently, the terminal 14 and the conductor 16 of the electric wire 12 can be joined with high strength in a short time.

[0026] Although the present embodiment has been described above, the present embodiment is not limited to this, and various modifications are possible within the scope of the gist of the present embodiment. [Explanation of symbols]

[0027] 10 Wires with terminals 12 Electric wire 14 terminals 14A Recess 14B 14C Slope 15 Flange 15A 15B Slope 16 Conductors 18 Covering part 20 Anvil 22 Horn 24 25 Sliding prevention jig 24A 24B Slope 25A recess 25B 25C Slope

Claims

1. A method for manufacturing an electric wire with a terminal, the method comprising: an electric wire having a conductor made of a plurality of metal wires; and a terminal to which the conductor is joined, the method comprising: a step A of bringing a sliding prevention jig into contact with the terminal placed on an anvil of an ultrasonic bonding machine to prevent sliding of the terminal; and step B of placing the conductor of the electric wire on the terminal against which the sliding prevention jig is in contact, pressing a horn against the conductor of the electric wire, and connecting the conductor and the terminal by ultrasonic welding, In the step A, the terminal and the sliding prevention jig are brought into contact with each other in an engaged and fixed state.

2. 2. The method for manufacturing an electric wire with a terminal according to claim 1, wherein the sliding prevention jig has a pair of inclined surfaces formed at both ends in the longitudinal direction of the electric wire, and a recess into which the sliding prevention jig fits is formed at the contact portion of the terminal with the sliding prevention jig, and a pair of inclined surfaces that engage with the pair of inclined surfaces of the sliding prevention jig are formed at both ends in the longitudinal direction of the electric wire of the recess.

3. 2. The method for manufacturing an electric wire with terminal according to claim 1, wherein a flange portion having a pair of inclined surfaces at both ends in the longitudinal direction of the electric wire is formed in the terminal at the contact portion with the sliding prevention jig, and a recess that fits into the flange portion of the terminal is formed in the contact portion of the sliding prevention jig with a pair of inclined surfaces that engage with the pair of inclined surfaces of the flange portion of the terminal at both ends in the longitudinal direction of the electric wire of the recess.

Images