JP2024151515A - Crimp terminal with electric wire and method for manufacturing the same - Google Patents

Abstract

[Problem] To provide a crimp terminal with electric wire that can remove an oxide film attached to a core wire at low cost and enables a stable electrical connection between the crimp terminal and the core wire. [Solution] A crimp terminal with electric wire (10) includes an electric wire (16) having an internal core wire (12) exposed from an insulating coating (14) at an end, and a crimp terminal (20) having a core wire crimping portion (18) to which the core wire (12) of the electric wire (16) is crimped, the core wire crimping portion (18) of the crimp terminal (20) has a bottom plate portion (26) on which the core wire (12) is placed and a pair of crimping pieces (28, 28) protruding from both sides of the bottom plate portion (26) and crimped to the core wire (12) on the bottom plate portion (26), the core wire crimping portion (18) having an extrusion protrusion (34) formed by extruding a part of at least one of the bottom plate portion (26) and the crimping piece (28) toward the core wire (12) in a middle region (α) excluding both side portions in the extension direction of the core wire (12). [Selected Figure] Figure 4

Description

This disclosure relates to a crimp terminal with electric wire and a method for manufacturing the crimp terminal with electric wire.

Conventionally, a crimp terminal with a wire has been widely used, in which a pair of crimping pieces formed on the core wire crimping portion of the crimp terminal are crimped and crimped to a core wire consisting of multiple strands exposed at the end of the wire from which the insulating coating has been stripped, thereby connecting the crimp terminal to the wire. In recent years, aluminum wires have been used in place of copper wires as wires used in automotive wire harnesses due to their light weight and recyclability. In the case of aluminum wires, a strong oxide coating with high electrical resistance is present on the surface of each strand, which leads to a decrease in electrical performance when connecting terminals. Therefore, Patent Document 1 proposes ultrasonically connecting the core wire exposed at the end of the aluminum wire before crimping and crimping. According to this, the strands from which the coating such as the oxide film formed on the surface of each strand has been stripped come into contact with each other and are electrically connected, thereby reducing the electrical resistance between the wire and the terminal.

JP 2009-231079 A

However, the structure of Patent Document 1 requires pre-processing of the exposed core wire at the end of the aluminum electric wire by ultrasonic connection, and then the core wire must be crimped with a pair of crimping parts of the core wire crimping part, which inevitably lengthens the manufacturing process and increases manufacturing costs.

Therefore, the objective of the present invention is to provide a crimp terminal with electric wire that can remove the oxide film adhering to the core wire at low cost and enable a stable electrical connection between the crimp terminal and the core wire, and a method for manufacturing the crimp terminal with electric wire.

The crimp terminal with electric wire of the present disclosure comprises an electric wire having an internal core wire exposed from an insulating coating at the terminal, and a crimp terminal having a core wire crimping portion to which the core wire of the electric wire is crimped, the core wire crimping portion of the crimp terminal having a bottom plate portion on which the core wire is placed and a pair of crimping pieces protruding from both sides of the bottom plate portion and crimped to the core wire on the bottom plate portion, and the core wire crimping portion has an extrusion protrusion formed by extruding a part of at least one of the bottom plate portion and the crimping pieces toward the core wire in a middle region excluding both side portions in the extension direction of the core wire.

The manufacturing method of the crimp terminal with electric wire disclosed herein includes preparing an electric wire having an internal core wire exposed from an insulating coating at the terminal, and a crimp terminal having a core wire crimping portion to which the core wire of the electric wire is crimped, the core wire crimping portion having a bottom plate portion on which the core wire is placed and a pair of crimping pieces protruding from both sides of the bottom plate portion, the core wire of the electric wire is placed on the bottom plate portion, the pair of crimping pieces are crimped and crimped to the core wire on the bottom plate portion, and after the crimping and crimping, a part of at least one of the bottom plate portion and the crimping pieces is pushed toward the core wire in an intermediate region excluding both sides in the extension direction of the core wire to form an extrusion protrusion.

According to the present disclosure, it is possible to provide a crimp terminal with electric wire and a method for manufacturing the crimp terminal with electric wire that can remove the oxide film attached to the core wire at low cost and enable a stable electrical connection between the crimp terminal and the core wire.

FIG. 1 is an exploded perspective view showing a state before crimping of an electric wire and a crimp terminal constituting an electric wire-attached crimp terminal according to a first embodiment. FIG. FIG. 2 is a plan perspective view of the crimp terminal with electric wire according to the first embodiment, which is formed by crimping the electric wire and the crimp terminal shown in FIG. FIG. 3 is a bottom perspective view of the crimp terminal with electric wire shown in FIG. 2 . 4 is a vertical cross-sectional view of the crimp terminal with electric wire shown in FIG. 2, which corresponds to the cross section taken along line IV-IV in FIG. FIG. 5 is a cross-sectional view corresponding to the VV section of FIG. FIG. 6 is a planar perspective view of the crimp terminal with electric wire according to the second embodiment. FIG. 7 is a cross-sectional view of the crimp terminal with electric wire shown in FIG. 6, and corresponds to FIG.

<Description of the embodiments of the present disclosure>
First, embodiments of the present disclosure will be listed and described.
The crimp terminal with electric wire of the present disclosure comprises:
(1) An electric wire having an internal core wire exposed from an insulating coating at an end thereof, and a crimp terminal having a core wire crimping portion to which the core wire of the electric wire is crimped, wherein the core wire crimping portion of the crimp terminal has a bottom plate portion on which the core wire is placed and a pair of crimping pieces protruding from both sides of the bottom plate portion and crimped to the core wire on the bottom plate portion, and the core wire crimping portion has an extrusion protrusion formed by extruding a portion of at least one of the bottom plate portion and the crimping pieces toward the core wire in an intermediate region excluding both side portions in the extension direction of the core wire.

According to the present disclosure, the core wire crimping portion of the crimping terminal to which the core wire is crimped has an extrusion protrusion formed by extruding a part of at least one of the bottom plate and the crimping piece toward the core wire in the middle region excluding both sides in the extension direction of the core wire. This makes it possible to improve the adhesion between the wires at the portion formed by extruding the extrusion protrusion toward the core wire in the core wire crimped and arranged in the core wire crimping portion. In other words, the partial high adhesion between the wires by the extrusion protrusion can partially remove the oxide film between the wires. Then, the wires are electrically connected by contacting each other, and the electrical resistance between the wire and the terminal can be reduced. In short, since it is only necessary to extrude at least a part of the bottom plate and the crimping piece of the core wire crimping portion to which the core wire is crimped toward the core wire to form the extrusion protrusion, the oxide film attached to the core wire can be removed at low cost, and a crimping terminal with a wire that enables a stable electrical connection between the crimping terminal and the core wire can be provided.

In particular, since the extrusion protrusion is provided in the middle region of the core wire crimping portion excluding both side portions in the extending direction of the core wire, the extrusion protrusion can be provided without both side portions where a bell mouth is likely to occur in the process of crimping the core wire with a pair of crimping pieces. This can prevent a problem in which the compressive force by the extrusion protrusion is released at the bell mouth forming portion and the core wires cannot be sufficiently tightly attached to each other, and the extrusion protrusion can stably achieve partial high adhesion between the strands of wires and reliably reduce the electrical resistance between the wire and the terminal. This can suppress an increase in resistance due to the thermal effect in the vehicle. In addition, since the extrusion protrusion is formed by extruding a part of at least one of the bottom plate portion and the crimping piece of the core wire crimping portion toward the core wire, the bottom plate portion and the crimping piece are not notched or have holes in them. Therefore, the occurrence of a problem in which the compressive force applied between the strands of wires by the extrusion protrusion escapes through the notches and holes is also suppressed. The extrusion protrusion only needs to be provided on a portion of the bottom plate of the core wire crimping portion and at least one of the pair of crimping pieces, and may be provided only on the bottom plate, only on one or both crimping pieces, or on both the bottom plate and the crimping pieces.

(2) In the above (1), it is preferable that the extrusion protrusion is disposed in the center of the intermediate region in the extension direction. Since the extrusion protrusion is provided in the center of the intermediate region of the core wire crimping portion in the extension direction of the core wire, it is possible to advantageously prevent the compression force exerted by the extrusion protrusion toward the inside of the core wire crimping portion from escaping to the outside of the core wire crimping portion due to the extension of the core wire, etc. As a result, it is possible to advantageously and stably secure the region where the extrusion protrusion realizes high density between the wires, and it is possible to more advantageously enable a stable electrical connection between the crimp terminal and the core wire.

(3) In the above (1) or (2), it is preferable that the extrusion protrusion is provided in the intermediate region of the bottom plate portion, and the protruding end face of the extrusion protrusion is arranged to face the tip portions of the pair of crimping pieces inserted inside the core wire in the extrusion direction of the extrusion protrusion. By providing the extrusion protrusion on the bottom plate portion, the core wire can be reliably compressed between the extrusion protrusion and the crimping piece. In particular, the protruding end face of the extrusion protrusion is arranged to face the tip portions of the pair of crimping pieces inserted inside the core wire. As a result, the compression rate of the core wire sandwiched between the extrusion protrusion and the crimping piece can be improved, and a stable electrical connection between the crimp terminal and the core wire due to the high density between the strands of wires caused by the extrusion protrusion can be more advantageously achieved.

(4) In the above (1) or (2), it is preferable that the extrusion protrusion is provided in the intermediate region on the base end side of each of the crimping pieces, and the protruding end face of the extrusion protrusion is arranged to face the tip portion of each of the crimping pieces inserted inside the core wire in the extrusion direction of the extrusion protrusion. By providing an extrusion protrusion on the base end side of each crimping piece, the core wire can be reliably compressed between a pair of extrusion protrusions facing each other in the extrusion direction. In particular, the protruding end face of each extrusion protrusion is arranged to face the tip portion of each crimping piece inserted inside the core wire. As a result, the compression rate of the core wire sandwiched between the extrusion protrusion and the crimping piece can be improved, and a stable electrical connection between the crimp terminal and the core wire due to the high density between the wires by the extrusion protrusion can be more advantageously achieved. In addition, by providing an extrusion protrusion on the base end of each of the pair of crimping pieces and clamping the core wire between the respective tip ends, it becomes easier to achieve an even compression state between the strands that make up the core wire on the left and right, which makes it possible to more effectively suppress the increase in resistance due to thermal effects in the vehicle compared to when the compression state is uneven.

(5) In the above (1) or (2), it is desirable that at least one of the bottom plate portion and the inner surface of the crimping piece is provided with a concave serration, and that the protruding dimension of the extrusion protrusion from the bottom plate portion or the inner surface of the crimping piece is greater than the depth dimension of the serration from the inner surface. This is because by making the protruding dimension of the extrusion protrusion larger than the depth dimension of the serration that provides resistance to pulling out of the core wire from the core wire crimping portion to the core wire, the extrusion protrusion can more reliably achieve the effect of improving the adhesion between the strands. More preferably, it is desirable that the protruding dimension of the extrusion protrusion is at least twice the depth dimension of the serration, and even more preferably at least three times.

The method for producing a crimp terminal with electric wire according to the present disclosure includes:
(6) A crimp terminal is prepared having an electric wire whose internal core wire is exposed from an insulating coating at a terminal, and a core wire crimping portion to which the core wire of the electric wire is crimped, the core wire crimping portion having a bottom plate portion on which the core wire is placed and a pair of crimping pieces protruding from both sides of the bottom plate portion, the core wire of the electric wire is placed on the bottom plate portion, and the pair of crimping pieces are crimped and crimped to the core wire on the bottom plate portion, and after the crimping and crimping, a portion of at least one of the bottom plate portion and the crimping pieces is pushed toward the core wire in an intermediate region excluding both side portions in the extension direction of the core wire to form an extrusion protrusion.

According to the manufacturing method of the crimp terminal with electric wire disclosed herein, the core wire of the electric wire is placed on the bottom plate of the crimp terminal, and the pair of crimping pieces is crimped toward the bottom plate with the core wire on the bottom plate sandwiched therebetween, and then a part of at least one of the bottom plate and the crimping pieces is pushed toward the core wire in the middle region excluding both sides in the extension direction of the core wire to form an extrusion protrusion. This improves the adhesion between the wires at the part where the extrusion protrusion is pushed toward the core wire in the core wire crimped and arranged on the core wire crimping part. As a result, the oxide coating between the wires is partially removed, and the wires are electrically connected by contacting each other, and the electrical resistance between the electric wire and the terminal can be reduced. Since it is only necessary to extrude a part of the core wire crimping part inward to form the extrusion protrusion after the core wire is crimped, the oxide coating attached to the core wire can be removed at low cost, and a crimp terminal with electric wire that enables a stable electrical connection between the crimp terminal and the core wire can be provided.

In particular, since the extrusion protrusion is provided in the middle region of the core wire crimping portion excluding both side portions in the direction in which the core wire extends, the extrusion protrusion can be provided excluding both side portions where a bell mouth is likely to occur during the process of crimping the core wire using a pair of crimping pieces. This allows the press process of forming the extrusion protrusion to be performed regardless of whether a bell mouth is present or not, resulting in excellent workability. Furthermore, it is possible to prevent problems in which the compression force from the extrusion protrusion is released at the bell mouth formation portion, making it impossible to sufficiently seal the core wires together, and the extrusion protrusion stably achieves high partial adhesion between the strands, thereby reliably reducing the electrical resistance between the electric wire and the terminal.

<Details of the embodiment of the present disclosure>
Specific examples of the crimp terminal with electric wire of the present disclosure will be described below with reference to the drawings. Note that the present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims.

<Embodiment 1>
Hereinafter, a crimp terminal with electric wire 10 according to a first embodiment of the present disclosure will be described with reference to Fig. 1 to Fig. 5. The crimp terminal with electric wire 10 includes an electric wire 16 having an inner core wire 12 exposed from an insulating coating 14 at a terminal thereof, and a crimp terminal 20 having a core wire crimping portion 18 to which the core wire 12 of the electric wire 16 is crimped.

<Electric wire 16>
1, the electric wire 16 has a core wire 12 as a conductor formed by twisting together a plurality of wires made of aluminum or an aluminum alloy, and the outer periphery of this core wire 12 is covered with an insulating coating 14 made of an insulating material. That is, at the end of the electric wire 16, a predetermined length of the insulating coating 14 is removed to expose the core wire 12. A crimp terminal 20 to be crimped and connected to this electric wire 16 is adapted to be crimped to the core wire 12 exposed at the end of the electric wire 16.

<Crimp terminal 20>
The crimp terminal 20 is formed by pressing a flat metal plate into a predetermined shape. As the metal constituting the metal plate, a metal having low electrical resistance such as copper or a copper alloy can be appropriately selected. The crimp terminal 20 is preferably plated with tin or nickel. The crimp terminal 20 has a connection portion 22 at one end (front end) in the longitudinal direction, and a core wire crimping portion 18 at the other end (rear end) in the longitudinal direction. The connection portion 22 has a circular flat plate shape, and a bolt insertion hole 24 is formed in the center. The crimp terminal 20 is electrically connected to the device by fastening the connection portion 22 to a connection terminal connected to a device not shown. The core wire crimping portion 18 has a cylindrical shape that opens in the front-rear direction, and the core wire 12 exposed at the end of the electric wire 16 is crimped to the core wire crimping portion 18. In this way, the crimp terminal 20 and the electric wire 16 are electrically connected to each other, forming the wire-attached crimp terminal 10 shown in FIG. 2.

More specifically, the core wire crimping portion 18 of the crimp terminal 20 has a bottom plate portion 26 on which the core wire 12 of the electric wire 16 is placed, and a pair of crimping pieces 28, 28 that are connected to both sides of the bottom plate portion 26 and protrude from both sides, and are crimped to the core wire 12. As shown in Figs. 1 and 4, a plurality of groove-shaped serrations 32 are provided on the inner surface 30 located between the pair of crimping pieces 28, 28 of the bottom plate portion 26. As a result, when the pair of crimping pieces 28 are crimped toward the bottom plate portion 26 with the core wire 12 sandwiched therebetween, the core wire 12 enters the serrations 32 to improve conductivity and provide resistance to pulling the core wire 12 out of the core wire crimping portion 18.

<Crimp terminal 10 with electric wire>
As shown in Fig. 2, the crimp terminal with electric wire 10 is configured in a state in which the core wire 12 exposed at the end of the electric wire 16 is crimped to the core wire crimping portion 18 of the crimp terminal 20 in a crimping step in a manufacturing method described below, thereby connecting the electric wire 16 and the crimp terminal 20. As shown in Figs. 3 to 5, the crimp terminal with electric wire 10 further has an extrusion protrusion 34 formed by extruding a part of the bottom plate portion 26 toward the core wire 12 in an intermediate region α excluding both side portions of the core wire crimping portion 18 in the extending direction of the core wire 12 (left and right direction in Fig. 4). In this embodiment, the extrusion protrusion 34 is located within the intermediate region α of the bottom plate portion 26 of the core wire crimping portion 18, and further in the central portion of the intermediate region α (see Fig. 4). Such an extrusion protrusion 34 can be formed by press-extruding or stamping a predetermined position of the bottom plate portion 26 from the outside to the inside, i.e., toward the core wire 12, in a press process described later with respect to the core wire crimping portion 18 of the crimp terminal 20 after the crimping process in which the electric wire 16 is crimped. By providing the extrusion protrusion 34 in the intermediate region α of the bottom plate portion 26, it is possible to advantageously avoid a problem in the press process after the crimping process in the manufacturing method described later, in which it becomes difficult to hold the core wire crimping portion 18 with a die in the press process due to the influence of a bell mouth (not shown) that is likely to be provided on both sides of the core wire crimping portion 18 in the crimping process. An open recess 35 is formed in the outer surface 33 of the bottom plate portion 26 in association with the formation of the extrusion protrusion 34.

As shown in FIG. 4, the protrusion dimension L1 of the extrusion protrusion 34 from the inner surface 30 of the bottom plate portion 26 is larger than the depth dimension L2 of the serration 32 from the inner surface 30 of the bottom plate portion 26, and is preferably set to be at least two times, more preferably at least three times, and in this embodiment is set to be at least three times.

As shown in FIG. 5, the extrusion protrusion 34 is provided at approximately the center of the width direction of the bottom plate portion 26 (the left-right direction in FIG. 5 perpendicular to the extension direction of the core wire 12), and the protruding end face 36 of the extrusion protrusion 34 is arranged in the extrusion direction of the extrusion protrusion 34 (upward direction in FIG. 5) facing the tip ends 38, 38 of the pair of crimping pieces 28, 28 inserted inside the core wire 12 by the crimping process. This ensures that the core wire 12 is compressed between the extrusion protrusion 34 and the crimping piece 28. In particular, it is possible to reliably improve the compression ratio of the core wire 12 sandwiched between the protruding end face 36 of the extrusion protrusion 34 and the tip ends 38, 38 of the pair of crimping pieces 28, 28. In addition, the protruding end face 36 spreads on a plane in a direction perpendicular to the facing direction of the tip ends 38, 38 of the pair of crimping pieces, and a compressive force can be applied to the core wire 12 over a wider range.

<Method of manufacturing the crimp terminal with electric wire 10>
A specific example of a method for manufacturing the crimp terminal 10 with electric wire will be described below.

First, the electric wire 16 shown in FIG. 1 is prepared by stripping the insulating coating 14 at the end of the electric wire 16 to expose the internal core wire 12. A metal flat plate is pressed and bent to prepare the crimp terminal 20 shown in FIG. 1. Next, the core wire 12 of the electric wire 16 is placed on the bottom plate 26 of the core wire crimping portion 18 of the crimp terminal 20. In this state, a crimping process is carried out in which the pair of crimping pieces 28, 28 of the core wire crimping portion 18 are crimped and crimped to the core wire 12 on the bottom plate 26.

More specifically, the core wire crimping portion 18 of the crimp terminal 20 with the core wire 12 of the electric wire 16 placed on the bottom plate portion 26 is placed on a lower die for crimping (not shown), and an upper die for crimping (not shown) is placed on top and pressed, so that the pair of crimping pieces 28, 28 are crimped toward the core wire 12 placed on the bottom plate portion 26. Next, the crimped electric wire 16 and crimp terminal 20 that are connected to each other and obtained in this crimping process are turned upside down. That is, a pressing process is performed to press out (strike out) the extrusion protrusion 34 in a state in which the bottom plate portion 26 of the core wire crimping portion 18 is oriented so as to be positioned upward as shown in FIG. In short, the core wire crimping portion 18 of the crimp terminal 20 is placed on a lower press die (not shown) with the bottom plate portion 26 of the core wire crimping portion 18 oriented so as to be positioned upward, and a press working is performed by placing an upper press die (not shown) (having a protrusion for forming the extrusion protrusion 34) on top from above. As a result, a predetermined portion of the bottom plate portion 26 of the core wire crimping portion 18 is extruded toward the core wire 12, forming the extrusion protrusion 34 shown in Figures 3 to 5. As the extrusion protrusion 34 is formed, a recessed portion 35 that opens into the outer surface 33 of the bottom plate portion 26 is provided.

In the crimp terminal with electric wire 10 of the present embodiment obtained in this manner, after the crimping process in which the pair of crimping pieces 28, 28 are crimped to the core wire 12 placed on the bottom plate portion 26 of the core wire crimping portion 18, a pressing process is performed in which a predetermined portion of the bottom plate portion 26 of the core wire crimping portion 18 is pushed toward the core wire 12 to press-form an extrusion protrusion 34. In the crimp terminal with electric wire 10 obtained in this manner, the core wire crimping portion 18 of the crimp terminal 20 to which the core wire 12 is crimped is provided with an extrusion protrusion 34 formed by extruding a part of the bottom plate portion 26 toward the core wire 12 in the middle region α excluding both side portions in the extension direction of the core wire 12. Therefore, the adhesion between the wires constituting the core wire 12 can be improved in the portion formed by extruding the extrusion protrusion 34 toward the core wire 12. This high adhesion between the wires allows the oxide film between the wires to be partially removed, and the wires are electrically connected by contacting each other, reducing the electrical resistance between the electric wire 16 and the crimp terminal 20. In particular, since it is only necessary to perform a pressing process on the core wire crimping portion 18 after the crimping process to form the extrusion protrusion 34, the oxide film adhering to the core wire can be removed at low cost, and it is possible to provide a wire-attached crimp terminal 10 that enables a stable electrical connection between the crimp terminal 20 and the core wire 12.

The extrusion protrusion 34 is located within the intermediate region α of the bottom plate portion 26 of the core wire crimping portion 18, and is further disposed in the center of the intermediate region α (see FIG. 3). This advantageously prevents the inward compressive force of the core wire crimping portion 18 caused by the extrusion protrusion 34 from escaping to the outside of the core wire crimping portion 18 due to the stretching of the core wire 12, etc. Therefore, the extrusion protrusion 34 can advantageously and stably achieve high density between the wires, and more advantageously ensure a stable electrical connection between the crimp terminal and the core wire.

In particular, in the first embodiment, as shown in Fig. 5, the protruding end face 36 of the extrusion protrusion 34 is disposed in the extrusion direction of the extrusion protrusion 34 (upward in Fig. 5) facing the tip ends 38, 38 of the pair of crimping pieces 28, 28 inserted into the core wire 12 by the crimping process. This reliably improves the compression ratio of the core wire 12 sandwiched between the protruding end face 36 of the extrusion protrusion 34 and the tip ends 38, 38 of the pair of crimping pieces 28, 28, and advantageously achieves high density between the strands of wire between the extrusion protrusion 34 and the crimping piece 28.

Here, the extrusion protrusion 34 is formed by pushing out a part of the bottom plate 26 of the core wire crimping portion 18 toward the core wire 12, so there is no need to cut out or provide holes in the bottom plate 26 or the crimping piece 28. This prevents the core wire 12 from deforming toward the cutouts or holes, which could cause the compression force applied between the strands by the extrusion protrusion 34 to escape.

In addition, the protrusion dimension L1 of the extrusion protrusion 34 from the inner surface 30 of the bottom plate portion 26 is set to be larger than the depth dimension L2 of the serration 32 from the inner surface 30, so that the extrusion protrusion 34 can more reliably improve the adhesion between the wires.

<Embodiment 2>
Next, a description will be given of a crimp terminal with electric wire 40 according to a second embodiment of the present disclosure with reference to Fig. 6 and Fig. 7. The crimp terminal with electric wire 40 according to the second embodiment differs from the crimp terminal with electric wire 10 according to the first embodiment in the location where a push-out protrusion 42, which will be described later, is formed. In the following description, differences between the crimp terminal with electric wire 40 according to the second embodiment and the crimp terminal with electric wire 10 according to the first embodiment will be described, and detailed description of the same members or parts as those according to the first embodiment will be omitted by assigning the same reference numerals in the drawings as those in the first embodiment.

<Crimp terminal 40 with electric wire>
As shown in Fig. 6, the crimp terminal with electric wire 40 has extrusion protrusions 42 formed by extruding a part of each crimping piece 28 toward the core wire 12 in an intermediate region α excluding both side portions of the core wire crimping portion 18 in the extending direction of the core wire 12 (left and right direction in Fig. 6). In the second embodiment, the extrusion protrusions 42 are arranged in the intermediate region α of the base end sides 44, 44 of the crimping pieces 28, 28 arranged opposite to each other on both sides in the width direction of the core wire crimping portion 18, and further in the central portion of the intermediate region α (see Fig. 6). Note that, in the above-mentioned pressing process, the core wire crimping portion 18 of the crimp terminal 20 is placed on a lower press die (not shown) in a state in which the crimping pieces 28 of the core wire crimping portion 18 are oriented so as to be arranged upward, and an upper press die (having a protrusion for forming the extrusion protrusions 42) (not shown) is placed on top to perform pressing. In conjunction with the formation of the extrusion protrusions 42, recesses 48 that open onto the outer surfaces 46 of the respective crimping pieces 28 are provided.

As shown in FIG. 7, the protruding end surface 50 of the extrusion protrusion 42 provided on the base end side 44 of each crimping piece 28 in the extrusion direction (left and right direction in FIG. 7) spreads flatly in a direction perpendicular to the protruding direction, and is disposed opposite the tip end 38 of each crimping piece 28 inserted inside the core wire 12. Although not shown, in the second embodiment, serrations 32 as in the first embodiment may be provided at appropriate positions on the inner surface 30 of the bottom plate portion 26 and the inner surface 52 of each crimping piece 28. If serrations 32 are provided, the protruding dimension L1 of the extrusion protrusion 42 from the inner surface 52 of the crimping piece 28 is made larger than the depth dimension L2 of the serrations 32 from the inner surface 30 of the bottom plate portion 26 and the inner surface 52 of the crimping piece 28, preferably two or more times, more preferably three or more times. Even if serrations are not provided, it is preferable that the protruding dimension L1 of the extrusion protrusion 42 is larger than the depth dimension of a general serration.

In the crimp terminal 40 with electric wire of the second embodiment, after the crimping process in which the pair of crimping pieces 28, 28 are crimped and crimped to the core wire 12 placed on the bottom plate 26 of the core wire crimping portion 18, a predetermined portion of each crimping piece 28 is pushed toward the core wire 12 in the pressing process to form an extrusion protrusion 42. Therefore, as in the first embodiment, the compression ratio of the core wire 12 sandwiched between the extrusion protrusion 42 and the crimping piece 28 can be improved, and a stable electrical connection between the crimp terminal 20 and the core wire 12 can be more advantageously realized by increasing the density between the strands by the extrusion protrusion 42. In particular, since the extrusion protrusion 42 is provided on the base end side 44 of each of the pair of crimping pieces 28 and the core wire 12 can be sandwiched between the respective tip portions 38, it is easy to realize an even compression state between the strands constituting the core wire 12 on the left and right, and the increase in resistance due to the thermal effect in the vehicle can be more advantageously suppressed compared to the case where the compression state is uneven. In addition, the extrusion protrusion 42 is located in the middle region α and is positioned in its central portion, which prevents the compression force from escaping. The extrusion protrusion 42 is also formed without a notch or hole, which prevents the compression force from escaping, similar to the first embodiment.

<Modification>
Although the first and second embodiments have been described above as specific examples of the present disclosure, the present disclosure is not limited to these specific descriptions. Modifications, improvements, etc., within the scope of achieving the object of the present disclosure, are included in the present disclosure. For example, the following modified examples of the embodiments are also included in the technical scope of the present disclosure.

(1) In the first embodiment, the extrusion protrusion 34 is extruded at one location on the bottom plate portion 26, but multiple extrusion protrusions 34 may be provided at multiple locations on the bottom plate portion 26. In the second embodiment, one extrusion protrusion 42 is provided on each crimping piece 28, but multiple extrusion protrusions 34 may be provided on each crimping piece 28, or one or multiple extrusion protrusions 42 may be provided on only one of the crimping pieces 28.

(2) In the first and second embodiments, the extrusion protrusions 34, 42 are provided on either the bottom plate portion 26 or the crimping piece 28, but they may be provided on both.

(3) In this embodiment, the serrations 32 are groove-shaped extending in a direction intersecting the extension direction of the core wire 12, but the shape and arrangement of the serrations 32 are not limited to this. For example, they may be groove-shaped, and may not extend in a groove-like manner, but may be formed of circular or polygonal recesses arranged in a dot pattern. Furthermore, the serrations may be formed on the inner surface of the crimping piece instead of or in addition to the bottom plate portion.

10 Crimp terminal with electric wire (embodiment 1)
12 Core wire 14 Insulating coating 16 Electric wire 18 Core wire crimping portion 20 Crimp terminal 22 Connection portion 24 Bolt insertion hole 26 Bottom plate portion 28 Crimping piece 30 Inner surface (bottom plate portion)
32 Serration 33 External surface (bottom plate)
34: Extrusion protrusion 35: Recessed portion 36: Protruding end surface 38: Tip portion (crimping piece)
40 Crimp terminal with electric wire (embodiment 2)
42: Extrusion protrusion 44: Base end side 46: Outer surface (crimping piece)
48: recessed portion 50: protruding end surface 52: inner surface (crimping piece)
α Intermediate region L1 Projection dimension of extrusion protrusion L2 Depth dimension of serration

Claims (6)

An electric wire having an inner core wire exposed from an insulating coating at a terminal;
a crimp terminal having a core crimping portion to which the core wire of the electric wire is crimped,
the core wire crimping portion of the crimp terminal has a bottom plate portion on which the core wire is placed, and a pair of crimping pieces protruding from both sides of the bottom plate portion and crimped to the core wire on the bottom plate portion,
The core wire crimping portion has an extrusion protrusion formed by extruding a portion of at least one of the bottom plate portion and the crimping piece toward the core wire in an intermediate region excluding both side portions in the extension direction of the core wire. The crimp terminal with electric wire according to claim 1, wherein the extrusion protrusion is provided in the center part of the intermediate region in the extension direction. The crimp terminal with electric wire according to claim 1 or 2, wherein the extrusion protrusion is provided in the intermediate region of the bottom plate portion, and the protruding end face of the extrusion protrusion is arranged opposite the tip end of the pair of crimping pieces inserted inside the core wire in the extrusion direction of the extrusion protrusion. The crimp terminal with electric wire according to claim 1 or 2, wherein the extrusion protrusion is provided in the intermediate region on the base end side of each of the crimping pieces, and the protruding end face of the extrusion protrusion is arranged to face the tip end of each of the crimping pieces inserted inside the core wire in the extrusion direction of the extrusion protrusion. The crimp terminal with electric wire according to claim 1 or 2, wherein at least one of the bottom plate portion and the inner surface of the crimping piece is provided with a concave serration, and the protrusion dimension of the extrusion protrusion from the bottom plate portion or the inner surface of the crimping piece is greater than the depth dimension of the serration from the inner surface. A crimp terminal is provided having an electric wire, the inner core of which is exposed from an insulating coating at a terminal thereof, and a core crimping portion to which the core of the electric wire is crimped;
the core wire crimping portion has a bottom plate portion on which the core wire is placed and a pair of crimping pieces protruding from both sides of the bottom plate portion, the core wire of the electric wire is placed on the bottom plate portion, and the pair of crimping pieces are crimped and crimped to the core wire on the bottom plate portion,
A method for manufacturing a crimp terminal with electric wire, wherein after the crimping, a portion of at least one of the bottom plate portion and the crimping piece is extruded toward the core wire in an intermediate region excluding both side portions in the extension direction of the core wire to form an extrusion protrusion.

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