Terminal fitting

Abstract

To provide a terminal fitting having a plate-like terminal fitting body, the terminal fitting providing a more sufficient joint strength than an ultrasound joint even when the terminal metal fitting body has a large thickness.SOLUTION: The terminal fitting includes a plate-like terminal fitting body including a conductor joint part to which a conductor part of an electric wire is joined, in one surface; and a recessed region in the opposite surface which faces the conductor joint part of the terminal fitting body. It is preferable that a trench extending in a direction which is vertical to the electric wire is formed in the conductor joint part of the terminal fitting body.SELECTED DRAWING: Figure 2A

Description

[Technical field]

[0001] The present invention relates to a terminal fitting. [Background technology]

[0002] As a method for connecting the conductor part of an electric wire to a metal terminal, an ultrasonic bonding method is known (see Patent Document 1). In such an ultrasonic bonding method, for example, an electric wire having a conductor end part made of multiple core wires exposed from an insulating outer sheath and a connection terminal formed by raising two side walls from a bottom surface are prepared. Then, the conductor end part is positioned on the bottom surface between the two side walls of the connection terminal, and ultrasonic vibration is applied while pressing it with a horn, and the terminal and the conductor are slid relative to each other, so that the terminal and the conductor are plastically deformed and bonded together. Also, among the terminals to be ultrasonically bonded, there is known a terminal having a convex shape at the part where the conductor is connected in order to increase the bonding area between the terminal and the conductor.

[0003] In order to obtain a good joint in ultrasonic bonding, it is effective to apply frictional heat or the like to promote plastic deformation between the parts to be connected, thereby raising the temperature. However, as the thickness of the terminal increases, it becomes difficult to raise the temperature of the terminal itself, making it difficult to obtain the necessary joint strength. In other words, it is difficult to obtain sufficient joint strength by applying ultrasonic bonding to a terminal with a thick plate thickness. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2006-172927 A Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in view of the problems inherent in the conventional techniques, and an object of the present invention is to provide a terminal fitting having a plate-shaped terminal body, which can obtain sufficient joining strength by ultrasonic joining even when the plate thickness of the terminal body is large. [Means for solving the problem]

[0006] A terminal fitting according to an embodiment of the present invention has a plate-shaped terminal fitting body including a conductor joint portion on one side to which a conductor portion of an electric wire is joined, and includes a concave-shaped area on the opposite side of the terminal fitting body facing the conductor joint portion. Effect of the Invention

[0007] According to the present invention, it is possible to provide a terminal fitting having a plate-shaped terminal fitting body, which can obtain sufficient joining strength by ultrasonic joining even if the terminal fitting body has a large plate thickness. [Brief description of the drawings]

[0008] [Figure 1A] FIG. 2 is a perspective view showing an example of an electric wire having an exposed conductor portion at an end portion. [Figure 1B] 1A and 1B are diagrams showing how a conductor portion of an electric wire is ultrasonically joined to a conductor joint portion of a terminal fitting; [Figure 2A] FIG. 2 is a perspective view showing an example of a terminal fitting according to the present embodiment. [Figure 2B] 2B is a rear view of the terminal fitting shown in FIG. 2A. FIG. [Figure 2C] FIG. 2C is a cross-sectional view taken along line AA in FIG. 2B. [Figure 3A] FIG. 2 is a perspective view showing an example of a terminal fitting according to the present embodiment. [Figure 3B] 3B is a rear view of the terminal fitting shown in FIG. 3A. FIG. [Figure 3C] FIG. 3C is a cross-sectional view taken along line BB in FIG. 3B. [Figure 4] FIG. 4 is a perspective view showing another example of the terminal fitting of the present embodiment. [Diagram 5]FIG. 4 is a perspective view showing another example of the terminal fitting of the present embodiment. [Figure 6] FIG. 4 is a perspective view showing another example of the terminal fitting of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a terminal fitting according to the present embodiment will be described in detail with reference to the drawings. Note that the dimensional ratios in the drawings are exaggerated for the convenience of explanation and may differ from the actual ratios.

[0010] The terminal fitting of the present embodiment includes a plate-shaped terminal fitting body having a conductor joint portion on one surface to which a conductor portion of an electric wire is joined, and a concave region on the opposite surface of the terminal fitting body facing the conductor joint portion.

[0011] First, the ultrasonic joining method will be described. Fig. 1A shows an electric wire 1 joined to a terminal fitting by ultrasonic joining. The electric wire 1 shown in Fig. 1A has a conductor portion 3 consisting of a plurality of core wires 2 exposed at an end. The electric wire 1 is made of a material that is easily plastically deformed (for example, an aluminum electric wire). The conductor portion 3 of the electric wire 1 is press-formed into a flat plate shape.

[0012] 1B shows a state in which a conductor portion 3 of an electric wire 1 is placed on a conductor joint portion 6 of a terminal fitting 4, and the conductor portion 3 and the conductor joint portion 6 are ultrasonically joined. A pressure vibration horn 13 is disposed above the conductor portion 3, and the conductor portion 3 is joined to the terminal fitting 4 by ultrasonic vibration while applying pressure from the pressure vibration horn 13. Such ultrasonic joining is described, for example, in JP 2006-172927 A.

[0013] Next, a specific example of the terminal fitting of this embodiment will be described. The terminal fitting 4A shown in Figs. 2A to 2C has a ring terminal 5 at the end of the terminal fitting body 8, and a crimping portion 9 at the rear. Between the ring terminal 5 and the crimping portion 9, a conductor joint portion 6 to which the conductor portion 3 of the electric wire 1 is joined is arranged. The ring terminal 5 has a ring hole, and when connecting to a mating connection terminal, a pin or a bolt is inserted into the ring hole to connect and fix. The crimping portion 9 is crimped with the electric wire 1 placed on the terminal fitting body 8, so that the insulating coating portion of the electric wire 1 is fixed. The conductor joint portion 6 has a groove 7 extending in a direction intersecting with the electric wire 1. The conductor joint portion 6 is bent at both side edges. That is, side walls exist at both side edges of the conductor joint portion 6. The conductor portion 3 of the electric wire 1 is arranged inside the side walls.

[0014] As shown in FIG. 2C, the surface of the terminal metal body 8 opposite to the conductor joint portion 6 includes a concave region 10. The concave region in FIG. 2C is rectangular when viewed from the back side. In other words, the surface opposite to the conductor joint portion 6 includes a concave region 10 whose plate thickness is thinner than the surrounding area. Therefore, the terminal metal body 8 has a region with a thin plate thickness in the conductor joint portion 6, and the heat capacity is smaller in the region than when the concave region 10 is not formed. Furthermore, when the conductor joint portion 6 and the conductor portion 3 of the electric wire 1 are ultrasonically joined, frictional heat due to relative sliding increases, and the temperature rises. As a result, plastic deformation is promoted and the joint strength is improved. Furthermore, the conductor joint portion 6 has a groove 7, and the heat capacity of the conductor joint portion 6 is smaller than when the groove 7 does not exist. Therefore, the terminal metal body of this embodiment can obtain sufficient joint strength by ultrasonic joining even when the plate thickness of the terminal metal body is thick.

[0015] From the viewpoint of reducing the heat capacity of the conductor joint 6, the concave region 10 is preferably formed over the entire area of ​​the surface opposite the conductor joint 6. The "entire area" refers to the area where the conductor parts of the electric wires are joined, projected onto the surface opposite the conductor joint 6, but may be a slightly larger area.

[0016] Although the concave region 10 shown in FIG. 2C is rectangular, it may have other shapes. There are no particular limitations on the other shapes as long as they can reduce the heat capacity of the conductor joint portion 6. For example, it may be circular, elliptical, or oval when viewed from the back surface side of the terminal fitting body 8. It may also be formed of multiple concave portions. Examples of multiple concave portions include triangular, rectangular, circular, elliptical, and oval shapes.

[0017] A different embodiment from the terminal fitting shown in Figs. 2A to 2C will be described. The terminal fitting 4B shown in Figs. 3A to 3C differs from the terminal fitting 4A shown in Figs. 2A to 2C only in the concave region 10 on the opposite side of the terminal fitting body 8 facing the conductor joint portion 6. Therefore, only the concave region 10, which is the difference, will be described. In the terminal fitting 4B shown in Figs. 3A to 3C, the multiple recesses in the concave region 10 are formed in a groove shape extending in a direction intersecting the electric wire, as shown in Fig. 3C. By configuring in this way, the heat capacity is reduced in the conductor joint portion 6 of the terminal fitting body 8, as in the terminal fitting shown in Figs. 2A to 2C, and the joining strength is improved. On the other hand, by forming the concave region 10 in a groove shape, the number of regions with a thin plate thickness in the conductor joint portion 6 is reduced compared to the terminal fitting 4C shown in Figs. 2A to 2C, and the decrease in strength can be suppressed. Therefore, for example, unintended deformation due to the pressure applied during ultrasonic joining can be prevented.

[0018] Even when the multiple recesses in the concave region 10 are groove-shaped as shown in FIG. 3C, the grooves do not have to be straight grooves, but may be curved grooves, and further, the grooves may be formed in a lattice pattern, concentric circles, or spiral pattern.

[0019] In the terminal fitting of this embodiment, the thinner the plate thickness of the conductor joint portion of the terminal fitting body is, the smaller the heat capacity is, but on the other hand, the thinner the plate thickness is, the lower the mechanical strength is. Therefore, it is preferable to set the area and depth of the concave region so as to reduce the heat capacity while preventing the mechanical strength from being lowered more than necessary.

[0020] 2A to 2C and 3A to 3C show the crimping portion 9, but the crimping portion 9 is not necessarily required. For example, a terminal fitting 4C shown in FIG. 4 may have no crimping portion 9. The terminal fitting 4C also includes a concave region 10 on the surface of the terminal fitting body 8 opposite to the conductor joint portion 6, as shown in FIG. 2C or 3C. Therefore, in ultrasonic bonding, the heat capacity in that region is reduced, improving the bonding strength.

[0021] 2A to 2C, 3A to 3C, and 4, the conductor joint portion 6 of the terminal fitting body 8 has a side wall formed thereon, but such a side wall is not necessarily required. For example, the conductor joint portion 6 may be entirely plate-shaped, as in the case of a terminal fitting 4D shown in Fig. 5. In the terminal fitting 4D as well, the surface of the terminal fitting body 8 opposite to the conductor joint portion 6 includes a concave region 10, as shown in Fig. 2C.

[0022] 2A to 2C, 3A to 3C, 4, and 5, a groove 7 extending in a direction intersecting the electric wire 1 is formed in the conductor joint portion 6 of the terminal fitting body 8, but the groove 7 is not necessarily required. For example, as in the terminal fitting 4E shown in Fig. 6, a groove does not have to be formed in the conductor joint portion 6. The terminal fitting 4E also includes a concave region 10 on the surface of the terminal fitting body 8 opposite to the conductor joint portion 6, as shown in Fig. 2C.

[0023] On the other hand, in order to increase the joining area with the conductor part of the electric wire, a convex shape may be formed at the conductor joint part of the terminal fitting body. In this embodiment, even if such a convex shape is formed at the conductor joint part, the concave region of the terminal fitting body is formed on the opposite surface facing the conductor joint part, so that the two do not interfere with each other.

[0024] 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]

[0025] 1 electric wire 2 Multiple cores 3 Conductor part 4 Terminal fittings 5 Ring Terminal 6 Conductor Joint 7 grooves 8 Terminal metal fitting body 9 Crimping part 10 Concave Areas 13 Pressure vibration horn

Claims

1. a plate-shaped terminal body including a conductor joint portion on one surface to which a conductor portion of an electric wire is joined; The terminal includes a concave region on a surface of the terminal body opposite the conductor joint portion.

2. The terminal fitting according to claim 1 , wherein the concave region is formed over the entire surface opposite to the conductor joint portion.

3. The terminal fitting according to claim 1 , wherein the concave region is formed by a plurality of recesses.

4. 3. The terminal according to claim 1, wherein a groove is formed in the conductor joint portion of the terminal body, the groove extending in a direction intersecting the electric wire.

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