JP2022008119A - Terminal-equipped electric wire, wiring harness, terminal, and terminal crimper - Google Patents

Abstract

To provide a terminal-equipped electric wire and the like, having excellent crimping workability and capable of realizing both connection strength and connection resistance.SOLUTION: A terminal-equipped electric wire 10 is constituted by a terminal 1 and a coated conductive wire 11 which are electrically connected to each other. A crimp part 5 of the terminal 1 is crimped to the coated conductive wire 11, and has a conductive wire crimp part 7 which is crimped to a conductive wire 13 that is exposed from a coating 15 on a front-end side of the coated conductive wire 11 and a coating crimp part 9 which is crimped to the coating 15 of the coated conductive wire 11. On a front-end side (terminal body 3 side) of the conductive wire crimp part 7, an electric wire holding part 7a which applies a relatively strong holding force on the conductive wire 13 is provided. On a rear-end side (coating crimp part 9 side) of the conductive wire crimp part 7, a conductive part 7b for achieving conduction with the conductive wire 13 is formed. The conductive wire crimp part 7 has a tubular shape to be closed in a peripheral direction.SELECTED DRAWING: Figure 1

Description

The present invention relates to, for example, an electric wire with a terminal used in an automobile or the like.

Usually, a wire harness for an automobile is bundled after a crimp terminal is connected to a conductor of a coated conductor wire, and is arranged as a signal line of an automobile or the like. In a general coated conductor and crimp terminal, the coating on the tip of the coated conductor is removed, the exposed conductor and the wire crimping portion are crimped, and the covering portion is crimped and connected by the coated crimping portion. The wire harness for automobiles satisfies the requirement of the connection strength between the crimp terminal and the coated lead wire by the sum of the connection strength of the wire crimping portion and the connection strength of the coated crimping portion.

Here, when the electric wire used becomes thin, it is difficult to maintain the strength only by the conductor constituting the electric wire, so an electric wire containing a tensile strength body is being studied. For example, when an electric wire made of a conductor having a tensile strength of about 30 N is used, the electric wire containing a tensile strength body is made of metal or non-metal in order to secure a tensile strength exceeding 80 N required for an automobile electric wire. It has been proposed that a conducting wire is spirally wound around the outer circumference of the tensile strength body. For such electric wires, the conductor is stripped off, the tensile strength body is exposed and inserted into the sleeve, the tensile strength body is crimped with a steel clamp, and the conductor portion is integrated with a curable resin such as an adhesive. There is a method of crimping with a clamp made of aluminum or the like (Patent Documents 1 and 2).

Jitsukaisho 61-046827 Gazette Japanese Unexamined Patent Publication No. 8-237389

In recent years, especially in the field of automobiles, the number of ECUs and sensors has increased due to the support of CASE and the like, and the number of electric wires used has increased remarkably accordingly. Under such circumstances, increasing the wire diameter of the wire harness becomes an issue. Therefore, there is a demand for a smaller diameter electric wire for automobiles. For example, a conventional electric wire having a small diameter of 0.35 sq (meaning sq: mm ² ) or less is required.

Here, in the conductor crimping portion, it is necessary to satisfy both the requirements of the connection strength between the electric wire and the terminal and the electrical connection resistance between the conductor and the terminal. As described above, in order to satisfy the required specifications for both the connection strength with the electric wire and the electrical connection resistance with the conductor, it is necessary to appropriately set the compressibility of the conductor crimping portion. However, as the wire diameter becomes smaller, it becomes difficult to satisfy both at the same compression rate.

For example, when connecting to a crimp terminal using a conventional technique using a thick-diameter coated conductor, crimping can be performed at the conductor crimping portion at a compression ratio that achieves both connection strength and connection resistance. As the diameter of the wire becomes smaller, the range of appropriate crimping conditions for both connection strength and electrical resistance becomes narrower. This is because when trying to secure the connection strength, the conductor breaks and the connection resistance becomes high, and when the connection resistance is emphasized, the connection strength cannot be obtained and it becomes a factor of disconnection of the electric wire. As described above, the smaller the wire diameter, the more difficult it is to achieve both connection strength and electrical resistance.

Further, when connecting the conventional electric wire containing a tensile strength body, a step stripping operation and a crimping process of crimping the tensile strength body and crimping the conducting wire are required. Therefore, the number of parts is large, the work man-hours are increased, and the cost is high. Especially when the diameter of the electric wire becomes small, the step peeling itself becomes difficult. As described above, the conventional method has a problem that the processing cost increases because the manufacturing process becomes complicated.

The present invention has been made in view of such a problem, and an object of the present invention is to provide an electric wire with a terminal, which has good crimping workability and can achieve both connection strength and connection resistance.

In order to achieve the above-mentioned object, the first invention is an electric wire with a terminal in which a coated wire and a terminal are electrically connected, and the terminal is crimped by a wire exposed from a covered portion at the tip of the coated wire. A wire crimping portion to be formed and a coated crimping portion to which the coated portion of the coated wire is crimped are provided, and at least a part of the wire crimping portion is a tubular shape closed in the circumferential direction, and the wire crimping portion is provided. An electric wire holding portion is provided on the tip end side of the wire, and a conducting portion for obtaining continuity with the conducting wire is formed on the rear end side of the conducting wire crimping portion. It is an electric wire with a terminal, which is characterized by being different.

It is desirable that the compression rate in the wire holding portion is smaller than the compression rate in the conductive portion.

The coated conductor may be composed of a plurality of the conductors and at least one tensile strength body.

In a cross section perpendicular to the longitudinal direction of the coated conductor, the tensile strength may be located substantially at the center of the coated conductor, and the conductor may be arranged on the outer peripheral portion of the tensile strength. Further, the conductor may be twisted in the longitudinal direction of the coated conductor.

At least the tip end portion of the conducting wire may be compressed from the outer peripheral side, or may be plated collectively from the outer peripheral side of the conducting wire.

The cross-sectional area of the conductor is 0.3 sq or less, and the terminal may be capable of crimping the lead wire having a cross-sectional area of 0.3 sq or less, and further, the cross-sectional area of the lead wire is 0.3 sq or less. The terminal may be capable of crimping the conducting wire having a cross-sectional area of 0.3 sq or less.

The compressibility in the coated crimping portion may be smaller than the compressibility in the conductive portion.

According to the first invention, the conductor crimping portion has two functional portions, a wire holding portion for holding the conductor in order to increase the connection strength and a conduction portion for ensuring continuity with the conductor in order to reduce the connection resistance. By dividing into, both the connection strength and the connection resistance can be satisfied. At this time, the work is easy because the wire crimping portion can be crimped by the same method as the conventional method.

In particular, since at least a part of the conductor crimping portion is tubular, the conductor can be reliably crimped from the entire circumference. Therefore, it is possible to suppress the occurrence of local stress (deformation) on the conductor during crimping.

Further, in this case, by making the compression ratio in the wire holding portion smaller than the compression ratio in the conductive portion, that is, by strongly compressing the wire holding portion, the connection strength between the terminal and the coated conductor can be more reliably obtained. Can be secured.

Further, since the coated conductor has at least one conductor and a tensile strength body, the tensile strength of the conductor wire can be ensured by the tensile strength body. At this time, if both the conducting wire and the tensile strength body are held by the electric wire holding portion, high connection strength can be ensured. Further, unlike the conventional case, it is not necessary to connect the tensile strength body and the conducting wire with separate clamps, so that the number of parts is small and the connection work is easy.

Further, if the conductor is arranged on the outer peripheral portion of the central tensile strength body in the cross section perpendicular to the longitudinal direction of the coated conductor, the conductor can be reliably crimped. At this time, the conducting wire may be twisted in the longitudinal direction on the outer peripheral portion of the tensile strength body.

Further, the tip of the conductor is tubular because the terminal processing portion is formed such that the tip of the conductor is compressed from the outer peripheral side or the outer periphery of the conductor is plated all at once. It is possible to prevent the conductor from coming apart when it is inserted into the conductor crimping portion.

Further, the present invention is particularly effective when a coated conductor having a small diameter of 0.3 sq or less in the cross-sectional area of the conductor and a coated conductor having a small diameter of 0.3 sq or less in the cross-sectional area of the conductor are used.

Further, by making the compression rate in the covering crimping portion smaller than the compressibility in the conductive portion, the covering portion can be reliably held.

The second invention is a wire harness characterized by integrating a plurality of terminald electric wires including the terminald electric wire according to the first invention.

According to the second invention, it is possible to obtain a wire harness in which a plurality of small-diameter electric wires are bundled.

A third invention is a terminal that is electrically connected to a coated wire, and a wire crimping portion to which a wire exposed from a coated portion at the tip of the coated wire is crimped and a wire crimping portion to which the coated portion of the coated wire is crimped. The covered crimping portion is provided, and at least a part of the lead wire crimping portion is a tubular shape closed in the circumferential direction, and an electric wire holding portion is provided on the tip end side of the lead wire crimping portion. A conductive portion for obtaining continuity with the lead wire is formed on the rear end side, and the terminal is characterized in that the electric wire holding portion and the conductive portion are separated.

According to the third invention, the electric wire with a terminal according to the first invention can be easily obtained.

The fourth invention is a terminal crimping blade type for manufacturing a wire with a terminal according to the first invention, which includes an upper blade type and a lower blade type, and the upper blade type and the lower blade type are Both the lead wire crimping portion and the covering crimping portion are formed so as to have a substantially circular cross section when the terminal is crimped, and the upper blade type and the upper blade type of the portion corresponding to the electric wire holding portion are described. The terminal crimping blade type is characterized in that the distance between the lower blade types is narrower than the distance between the upper blade type and the lower blade type at the portion corresponding to the conduction portion.

According to the fourth invention, the coated conductor and the terminal can be easily crimped by the same process as the conventional electric wire with a terminal.

According to the present invention, it is possible to provide an electric wire with a terminal, which has good crimping workability and can achieve both connection strength and connection resistance.

The perspective view which shows the electric wire 10 with a terminal. The cross-sectional view which shows the electric wire 10 with a terminal. (A) to (c) are cross-sectional views of the electric wire holding portion 7a. The figure which shows the terminal 1 and the coated conductor wire 11 before crimping. (A) is a diagram showing the tip of the conductor 13, (b) is a diagram showing the tip of the conductor 13 before terminal processing, and (c) and (d) are diagrams showing the form of the terminal processing unit 19. .. (A) and (b) are diagrams showing the form of another terminal processing unit 19. (A) and (b) are views showing the crimping process of the crimping portion 5. The figure which shows the terminal 1a and the coated conductor wire 11 before crimping. The figure which shows the terminal 1b and the coated conductor wire 11 before crimping. The figure which shows the terminal 1c and the coated conductor wire 11 before crimping. The figure which shows the terminal 1d and the coated conductor wire 11 before crimping. The figure which shows the terminal 1e and the coated conductor wire 11 before crimping. The plan view which shows the electric wire 10a with a terminal. (A) and (b) are views showing the cross section of another coated conductor wire 11.

(First Embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing an electric wire 10 with a terminal, and FIG. 2 is a cross-sectional view of the electric wire 10 with a terminal. The electric wire 10 with a terminal is configured by electrically connecting the terminal 1 and the coated conductor wire 11.

The coated lead wire 11 includes, for example, a lead wire 13 made of copper, a copper alloy, aluminum, or an aluminum alloy, and a covering portion 15 that covers the lead wire 13. That is, the coated conductor 11 includes a coated portion 15 and a conductor 13 exposed from the tip thereof.

The terminal 1 is made of, for example, copper, a copper alloy, aluminum or an aluminum alloy. A coated conducting wire 11 is connected to the terminal 1. The terminal 1 is configured by connecting the terminal body 3 and the crimping portion 5 via the transition portion 4.

The terminal body 3 is formed by forming a plate-shaped material having a predetermined shape into a tubular body having a rectangular cross section. The terminal body 3 has an elastic contact piece formed by folding a plate-shaped material into a rectangular cylinder. The terminal body 3 is connected by inserting a male terminal or the like from the front end portion. In the following description, an example is shown in which the terminal body 3 is a female terminal that allows insertion of an insertion tab (not shown) such as a male terminal, but in the present invention, the detailed shape of the terminal body 3 is shown. Is not particularly limited. For example, instead of the female terminal body 3, a male terminal insertion tab may be provided, or a bolt fastening portion such as a round terminal may be provided.

The crimping portion 5 of the terminal 1 is a portion to be crimped to the coated conductor wire 11, and the conductor wire crimping portion 7 for crimping the conductor wire 13 exposed from the coated conductor portion 15 to the tip end side of the coated conductor wire 11 and the coated portion 15 of the coated conductor wire 11. It has a coated crimping portion 9 for crimping. That is, the conductor 13 exposed by peeling off the covering portion 15 is crimped by the conductor crimping portion 7, and the conductor 13 and the terminal 1 are electrically connected. Further, the coated portion 15 of the coated conducting wire 11 is crimped by the coated crimping portion 9 of the terminal 1. In the present embodiment, the lead wire crimping portion 7 and the covering crimping portion 9 are integrally formed into a tubular shape (substantially cylindrical shape) closed in the circumferential direction.

A part of the inner surface of the wire crimping portion 7 may be provided with serrations (not shown) in the width direction (direction perpendicular to the longitudinal direction). By forming the serrations in this way, when the conductor 13 is crimped, the oxide film on the surface of the conductor 13 is easily broken, and the contact area with the conductor 13 can be increased.

An electric wire holding portion 7a having a relatively strong holding force of the conducting wire 13 is provided on the tip end side (terminal main body 3 side) of the conducting wire crimping portion 7. Further, a conducting portion 7b for obtaining continuity with the conducting wire 13 is formed on the rear end side (covered crimping portion 9 side) of the conducting wire crimping portion 7. That is, the wire crimping portion 7 has a wire holding portion 7a and a conductive portion 7b.

The tensile strength (connection strength) of the conductor 13 in the wire holding portion 7a is stronger than the tensile strength (connection strength) of the conductor 13 in the conductive portion 7b. For example, the compressibility in the wire holding portion 7a (cross-sectional area of the conductor 13 after compression / cross-sectional area of the conductor 13 before compression) is smaller than the compressibility in the conductive portion 7b. That is, the amount of compression in the wire holding portion 7a is larger than the amount of compression in the conductive portion 7b, and the wire holding portion 7a is strongly crimped.

In this way, since the wire holding portion 7a is strongly crimped, at least a part of the conducting wire 13 may be broken. Although the electrical resistance increases when a part of the conducting wire 13 breaks, a part of the fiber of the tensile strength body 17 enters into the gap of the broken conducting wire 13 to increase the pull-out resistance of the conducting wire 13 and connect strength. Can be secured. On the other hand, in the conductive portion 7b, the conducting wire 13 is not broken in order to keep the electric resistance low.

The compressibility of the covering crimping portion 9 (cross-sectional area of the covering portion 15 after compression / cross-sectional area of the covering portion 15 before compression) may be smaller than the compressibility of the conductive portion 7b. That is, the amount of compression in the covering crimping portion 9 may be larger than the amount of compression in the conductive portion 7b. Even in this case, the outer diameter of the covering crimping portion 9 is larger than the outer diameter of the conductive portion 7b due to the thickness of the covering portion 15.

FIG. 3A is a diagram showing a cross section of the electric wire holding portion 7a. In the example shown in FIG. 3A, the conductor 13 is composed of seven strands. In the wire holding portion 7a, the conducting wire 13 is compressed into a substantially circular shape and crimped. The shape of the wire holding portion 7a after crimping does not necessarily have to be substantially circular, but it is desirable that the cross-sectional shape of the conductive portion 7b after crimping is substantially circular.

The number of strands of the conductor 13 is not particularly limited. For example, as shown in FIG. 3B, the number of strands may be 16. It is desirable that the strands are twisted together.

Further, in the coated conducting wire 11, at least one conducting wire 13 and a tensile strength body may be covered with a covering portion 15. The tensile strength body is a member that receives tension with respect to a tensile load. For example, as shown in FIG. 3 (c), in a cross section perpendicular to the longitudinal direction of the coated conductor 11, at least one tensile strength body 17 is located substantially in the center of the coated conductor 11, and a plurality of conductors 13 are the tensile strength bodies 17. It may be arranged on the outer peripheral portion of the. At this time, each of the conductors 13 (wires) arranged on the outer periphery of the tensile strength body 17 may be a conductor 13 (wire) having the same cross-sectional area and the same shape. Further, the conducting wire 13 may be spirally twisted in the longitudinal direction of the coated conducting wire 11 on the outer peripheral portion of the tensile strength body 17. In this case, in the electric wire holding portion 7a and the conductive portion 7b, both the conducting wire 13 and the tensile strength body 17 are crimped and held.

The arrangement of the tensile strength body 17 is not limited to the example shown in FIG. 3 (c). For example, the conductor 13 and the tensile strength body 17 may be arranged so as to be twisted together. Further, a plurality of conductors 13 in which the tensile strength body 17 is covered with a conductor may be twisted together. Further, the conductor may be arranged so as to cover the outer periphery of the central tensile strength body 17. That is, in the case of the coated conducting wire 11 containing the tensile strength body, the cross-sectional form thereof is not particularly limited as long as it has at least one conducting wire and at least one tensile strength body. The tensile strength body 17 may be a single (integral) tensile strength wire, or may be composed of a plurality of strands.

Here, it is desirable that the cross-sectional area of the conductor 13 (total cross-sectional area of the strands) is 0.3 sq or less, and in this case, the terminal 1 crimps the conductor 13 having a cross-sectional area of 0.3 sq or less. It is desirable to be possible. Further, it is desirable that the cross-sectional area of the conductor 13 (total cross-sectional area of the strands) is 0.3 sq or less, and in this case, the terminal 1 crimps the conductor 13 having a cross-sectional area of 0.3 sq or less. It is desirable to be possible. Further, for example, when the conductor 13 is used together with the tensile strength body 17, the cross-sectional area of the conductor 13 may be 0.05 sq or less. The smaller the cross-sectional area of the conducting wire 13, the greater the effect of this embodiment.

The tensile strength body 17 may be a metal wire such as a steel wire, or may be a resin or a fiber reinforced resin. Further, as described above, the tensile strength body 17 may be a single wire or a bundle of a plurality of fibers such as aramid fibers. By using such a tensile strength body 17, for example, even if the cross-sectional area of the conducting wire 13 is 0.05 sq or less, it is possible to secure 50 N or more as the tensile strength of the conducting wire in the wire holding portion 7a.

Next, a method of manufacturing the electric wire 10 with a terminal will be described. FIG. 4 is a perspective view showing the terminal 1 and the coated conductor wire 11 before crimping. As described above, the terminal 1 has a terminal body 3 and a crimping portion 5. In the crimping portion 5, the lead wire crimping portion 7 and the covering crimping portion 9 are integrally formed in a substantially cylindrical shape. The crimping portion 5 may be joined by welding in the longitudinal direction, for example, by rolling the plate members and abutting the ends thereof, or by expanding the tubular member to form the terminal 1. The conductor crimping portion 7 and the covering crimping portion 9 may have the same diameter, but as shown in the figure, the inner diameter of the conducting wire crimping portion 7 is substantially constant, and the inner diameter of the covering crimping portion 9 is set to the conducting wire crimping portion. It may be larger than the inner diameter of 7.

First, as described above, the coated portion 15 at the tip of the coated conductor 11 is peeled off to expose the conductor 13 at the tip. Next, as shown in FIG. 5A, the terminal processing portion 19 may be formed at the tip end portion of the conducting wire 13 before being inserted into the crimping portion 5 of the terminal 1. The terminal processing unit 19 is a processing unit that integrates the strands of the conductor 13 so that they do not come apart.

FIG. 5B is a diagram showing the shape of the tip of the conducting wire 13 before the terminal processing. In the present embodiment, the tensile strength body 17 is arranged substantially in the center when viewed from the tip of the coated conductor wire 11, and the conductor wire 13 is arranged on the outer periphery thereof. The conductor 13 is composed of a plurality of strands. In this embodiment, the case where the tensile strength body 17 is provided in the center will be described, but the same applies to other coated conductors.

In such a case, as shown in FIG. 5C, the terminal processing unit 19 can be formed by compressing at least the tip portion of the conducting wire 13 from the outer peripheral side. As described above, the tip portion of the conducting wire 13 is compressed from the outer peripheral side, so that the strands are prevented from being loosened and can be easily inserted into the tubular crimping portion 5.

Further, as shown in FIG. 5D, at least the tip end portion of the conducting wire 13 may be collectively subjected to a turning treatment to form the terminal processing portion 19 by the plating layer 21. As described above, since the tip portion of the conducting wire 13 is collectively plated from the outer periphery, the strands are prevented from being loosened, and it is easy to insert the conductor into the tubular crimping portion 5.

In addition, when the plating process is performed collectively from the outer periphery of the conducting wire 13, the temperature may become high depending on the plating method. If batch plating is performed after twisting the conducting wire 13 by such a plating method, the tensile strength body 17 may be deteriorated by heat and the tensile strength may be lowered.

In such a case, as shown in FIG. 6A, a plating layer 21 may be formed for each conductor and then twisted around the outer periphery of the tensile strength body 17. Further, as shown in FIG. 6B, a plating layer 21 may be formed for each conductor, and further, the tip portions of a plurality of conductors may be collectively plated from the outer periphery. In this case, the type of plating for each conductor and the type of batch plating may be changed. It is possible to suppress the dispersal of conductors by performing batch plating, but if the conductors are bundled and plated collectively, due to the influence of the shape of the conductor, etc., the part with thick plating may be partially plated. There is a risk that thin parts will be created. On the other hand, by performing the base plating treatment for each conductor in advance, this influence can be reduced and substantially uniform batch plating can be performed.

The terminal processing unit 19 is not limited to the method by compression or plating, and may, for example, suppress the dispersal of the strands by soldering or welding the tip of the conducting wire 13. Further, a plurality of terminal processes such as compression from the outer circumference and batch plating may be used in combination.

Next, the coated lead wire 11 having the tip portion treated in this way is inserted from the rear end portion side of the tubular crimping portion 5 of the terminal 1. When the tip end portion of the coated conductor 11 is inserted into the crimping portion 5, the exposed portion of the conducting wire 13 is located inside the wire crimping portion 7, and the covering portion 15 is located inside the coated crimping portion 9. At this time, the tip of the conductor 13 may protrude from the tip of the conductor crimping portion 7.

FIG. 7A is a cross-sectional view showing the upper blade type 31a, the lower blade type 31b, etc. before crimping the terminal crimping blade type for manufacturing the electric wire 10 with terminals, and FIG. 7B is crimping during crimping. It is sectional drawing which shows the part 5. The upper blade type 31a and the lower blade type 31b have a substantially semi-cylindrical cavity extending in the longitudinal direction. Further, the upper blade type 31a corresponds to the coated crimping portion 9 and has a diameter slightly smaller than the radius of the coated crimping portion 9, and corresponds to the lead wire crimping portion 7 and from the coated crimping blade type 34. Also provided with a wire crimping blade type 32a, 32b having a small diameter. That is, the upper blade type 31a and the lower blade type 31b are formed so that both the portions corresponding to the lead wire crimping portion 7 and the covering crimping portion 9 have a substantially circular cross section when the terminal 1 is crimped.

The wire crimping blade type 32a is a blade type corresponding to the electric wire holding portion 7a, and the wire crimping blade type 32b is a blade type corresponding to the conductive portion 7b. That is, the diameter of the wire crimping blade type 32a is smaller than the diameter of the wire crimping blade type 32b, and the distance between the upper blade type 31a and the lower blade type 31b of the portion corresponding to the wire holding portion 7a corresponds to the conductive portion 7b. It is narrower than the distance between the upper blade type 31a and the lower blade type 31b of the portion.

The length of the conductive portion 7b may be relatively longer than that of the electric wire holding portion 7a in order to ensure the continuity between the coated lead wire 11 and the terminal 1. On the other hand, even if the length of the wire holding portion 7a is short, if the conducting wire 13 or the tensile strength body 17 and the terminal 1 are in close contact with each other at an appropriate pressure, the strength of both is sufficiently high. The length of 7a may be relatively shorter than that of the conductive portion 7b.

As shown in FIG. 7B, when the upper blade mold 31a and the lower blade mold 31b are engaged with each other and the crimping portion 5 is compressed, the conductor crimping portion 7 is crimped to the conductor wire 13, and the covering crimping portion 9 is a covering portion. It is crimped to 15. At this time, the wire holding portion 7a has the smallest diameter, then the conductive portion 7b has the smallest diameter, and the covering crimping portion 9 has the largest diameter. From the above, the electric wire 10 with a terminal can be obtained. Further, it is possible to obtain a wire harness in which a plurality of electric wires with terminals are integrated, including the obtained electric wire with terminals 10.

As described above, the compressibility of the electric wire holding portion 7a is smaller than the compressibility of the conductive portion 7b, and the compressibility of the covering crimping portion 9 is smaller than the compressibility of the conductive portion 7b. Here, the cross-sectional area of the covering portion 15 before the crimping step (the total cross-sectional area inside the outer peripheral surface of the covering crimping portion 9) is set to A0, and the covering crimping portion after being compressed by the upper blade mold 31a and the lower blade mold 31b. Assuming that the cross-sectional area inside the 9 is A2, the compression ratio of the covering crimping portion 9 = A2 / A0 (%).

Similarly, the cross-sectional area of the lead wire 13 before the crimping step (in the case where the tensile strength body is included, the total cross-sectional area of the lead wire 13 including the tensile strength body) is set to A1, and is compressed by the upper blade type 31a and the lower blade type 31b. Assuming that the cross-sectional areas inside the conductive portion 7b and the wire holding portion 7a (the total cross-sectional area of the lead wire 13 including the tensile strength body when the tensile strength body is included) are A3 and A4, respectively, the wire holding portion 7a is compressed. The rate = A4 / A1 (%), and the compression rate of the conductive portion 7b = A3 / A1 (%).

Since the tensile strength body 17 has higher strength and is less likely to be deformed than the conducting wire 13, the cross-sectional area of the tensile strength body 17 does not significantly decrease during compression, and the deformation of the conducting wire 13 (decrease in cross-sectional area) mainly progresses. ..

Here, when the tensile strength body 17 is formed of a plurality of strands, each strand is finer than the conductor constituting the conductor 13, and is between the tensile strength strands and the tensile strength strands. It is difficult to clearly distinguish the gaps. Therefore, the cross-sectional area of the tensile strength body 17 before crimping is the area of the region of the tensile strength body surrounded by the conductor 13. In this case, in the early stage of compression, the deformation of the lead wire 13 progresses while the tensile strength body is deformed so as to reduce the gap between the strands of the tensile strength body. The cross-sectional reduction of 13 mainly progresses. Therefore, the compressibility of the conductor 13 after crimping is equal to or less than the apparent compressibility of the region where the tensile strength body 17 is arranged. The area ratio of the conductor wire 13 and the tensile strength body 17 after compression changes depending on the compression ratio of the entire electric wire.

Further, due to the movement of the tensile strength body wire during compression, the outer shape of the tensile strength body 17 becomes uneven, so that the contact area between the conducting wire 13 and the tensile strength body 17 increases and the frictional force increases. Therefore, the force is easily transmitted from the conductor 13 to the tensile strength body 17 with respect to the tension, and it is expected that the strength will increase when the tensile force is applied to the conductor 13.

Since the tensile strength body 17 has a smaller amount of deformation than the conducting wire 13, it is unlikely to break due to a decrease in the cross-sectional area. In particular, since the conductor crimping portion 7 is tubular, the conductor 13 is compressed from the entire circumference, the conductor 13 is arranged between the tensile strength body 17 and the conductor crimping portion 7, and the tensile strength body 17 and the conductor crimping portion 7 do not come into contact with each other. Therefore, the tensile strength body 17 is not damaged.

At the time of compression, a part of the strands constituting the tensile strength body 17 may enter between the conducting wires 13, and a part of the tensile strength body 17 may come into contact with the conducting wire crimping portion 7. As described above, it is desirable that the tensile strength body 17 and the wire crimping portion 7 do not come into contact with each other, but a part of the tensile strength body 17 may slightly contact the wire crimping portion 7. For example, if the peripheral length of the tensile strength body 17 in contact with the wire crimping portion 7 is 30% or less of the total outer peripheral length of the tensile strength body 17 in an arbitrary cross section, the damage suppressing effect of the tensile strength body 17 can be obtained. Can be done.

As described above, according to the present embodiment, since the wire crimping portion 7 has the wire holding portion 7a and the conducting portion 7b, the wire holding portion 7a is crimped at a compression rate suitable for ensuring the connection strength. Then, the conduction portion 7b can be crimped at a compression rate suitable for ensuring continuity. That is, since the compressibility (compression amount) of each of the wire holding portion 7a and the conductive portion 7b can be made different, each portion can be crimped at a compression rate suitable for the purpose.

More specifically, by using the wire holding portion 7a on the tip end side (terminal body 3 side) of the lead wire crimping portion 7, stronger crimping can be performed and high connection strength can be ensured. At this time, a part of the conducting wire 13 may be broken. On the other hand, since the conductive portion 7b is arranged on the rear end portion side (covered portion 15 side) of the conducting wire crimping portion 7, even if a part of the conducting wire 13 is broken in the wire holding portion 7a, the coated conducting wire 11 and the conductive portion 7b are arranged. Continuity with the terminal 1 can be ensured.

Further, since the crimping work can be performed in the same work as the crimping of a normal electric wire with a terminal, the work is easy. In particular, it can be applied to the coated conductor 11 including the tensile strength body 17, and in this case, even the coated conductor 11 having a small diameter can secure high connection strength.

At this time, since both the tensile strength body 17 and the conducting wire 13 are collectively crimped by the electric wire holding portion 7a, it is not necessary to crimp the tensile strength body 17 and the conducting wire 13 separately, and the crimping work is easy. In the case of the coated conductor 11 including the tensile strength body 17, the tensile strength body 17 is arranged substantially in the center of the cross section and the conductor wire 13 is arranged on the outer periphery thereof so that the terminal 1 and the conductor wire 13 can be securely crimped at the time of crimping. The terminal 1 and the conducting wire 13 can be brought into contact with each other.

Further, since the conductor crimping portion 7 has a substantially cylindrical shape, crimping can be reliably performed from the entire circumference of the conductor 13 at 360 °. Therefore, it is possible to suppress the occurrence of local stress (deformation) on the conducting wire 13 at the time of crimping.

Here, in the conductor crimping portion 7 of the coated conductor 11 in which the conductor 13 is arranged around the tensile strength body 17, when crimping is performed, a compressive stress acts in the radial direction inside the conductor crimping portion 7. When this compressive stress is small, the frictional force on the contact surface between the conductor 13 and the tensile strength body 17 becomes smaller than the frictional force on the contact surface between the terminal 1 and the conductor 13. Therefore, when a tensile load is applied to the electric wire 10 with terminals, the load is concentrated on the conductor 13, and the conductor 13 is likely to break.

On the other hand, slippage occurs on the contact surface between the lead wire 13 and the tensile strength body 17, compressive stress does not act on the tensile strength body 17, a phenomenon occurs in which the tensile strength body 17 comes off without cutting, and the tensile strength of the tensile strength body 17 is sufficient. It may not be expressed in. In order to prevent the above phenomenon and obtain sufficient compressive stress by crimping, the frictional force between the conductor 13 and the tensile strength body 17 may be increased. For example, by providing unevenness on the inner surface of the wire crimping portion 7, it is possible to partially increase the compressive stress on the tensile strength body 17 and prevent it from being pulled out.

Further, when the conductor crimping portion 7 has a cylindrical shape and the joint portion has a brazed portion, the brazed portion having a low hardness has a small compressive stress on the conductor 13, so that the tensile strength body 17 is pulled out. It will be easier. Therefore, it is desirable to remove the brazed portion or to make the hardness of the joint portion formed in the conductor crimping portion 7 without the brazing portion equal to the hardness of the material in the conductor crimping portion 7.

(Second embodiment)
Next, the second embodiment will be described. FIG. 8 is a perspective view before the covered conductor 11 of the terminal 1a according to the second embodiment is crimped. In the following description, the same reference numerals as those in FIGS. 1 to 7 will be given to the configurations having the same functions as those of the first embodiment, and duplicate description will be omitted.

The terminal 1a has substantially the same configuration as the terminal 1, but the form of the crimping portion 5 is different. The terminal 1a has a slit formed between the lead wire crimping portion 7 and the covering crimping portion 9. That is, the lead wire crimping portion 7 and the covering crimping portion 9 are formed separately.

The terminal 1a can also be crimped in the same manner as the terminal 1. In this case, the end portion of the covering portion 15 may be crimped so as to be located at the slit portion between the lead wire crimping portion 7 and the covering crimping portion 9. In this way, by crimping the wire crimping portion 7 so as to form the electric wire holding portion 7a and the conductive portion 7b, the same effect as that of the first embodiment can be obtained.

(Third embodiment)
Next, a third embodiment will be described. FIG. 9 is a perspective view of the terminal 1b according to the third embodiment before crimping. The terminal 1b has substantially the same configuration as the terminal 1a, but the form of the crimping portion 5 is different. Before crimping, the terminal 1b is provided with an electric wire holding portion 7a on the tip end side of the conductor crimping portion 7, and a conduction portion 7b for obtaining continuity with the conductor is formed on the rear end side of the conductor crimping portion 7. The electric wire holding portion 7a and the conductive portion 7b are divided via a slit. In this case, the wire holding portion 7a and the conductive portion 7b may have different diameters.

The terminal 1b can also be crimped in the same manner as the terminal 1 and the like. In this way, by forming and crimping the electric wire holding portion 7a and the conductive portion 7b in the lead wire crimping portion 7, the same effect as that of the first embodiment can be obtained.

(Fourth Embodiment)
Next, a fourth embodiment will be described. FIG. 10 is a perspective view of the terminal 1c according to the fourth embodiment before crimping. The terminal 1c has substantially the same configuration as the terminal 1a, but the form of the crimping portion 5 is different. The terminal 1c has an open barrel type covering crimping portion 9. That is, the lead wire crimping portion 7 is tubular, and the covering crimping portion 9 is an open barrel type, both of which have different forms. As described above, the covering crimping portion 9 may be an open barrel type instead of a tubular type.

The terminal 1c can also be crimped in the same manner as the terminal 1 and the like. That is, by forming and crimping the electric wire holding portion 7a and the conductive portion 7b in the lead wire crimping portion 7, the same effect as that of the first embodiment can be obtained.

(Fifth Embodiment)
Next, a fifth embodiment will be described. FIG. 11 is a perspective view of the terminal 1d according to the fifth embodiment before crimping. The terminal 1d has substantially the same configuration as the terminal 1c, but the form of the crimping portion 5 is different. In the terminal 1d, a slit is formed between the electric wire holding portion 7a and the conductive portion 7b in the tubular lead wire crimping portion 7. That is, the wire holding portion 7a and the conductive portion 7b are separated and formed before crimping. In this case, the wire holding portion 7a and the conductive portion 7b may have different diameters.

The terminal 1d can also be crimped in the same manner as the terminal 1 and the like. In this way, by forming and crimping the electric wire holding portion 7a and the conductive portion 7b in the lead wire crimping portion 7, the same effect as that of the first embodiment can be obtained.

(Sixth Embodiment)
Next, the sixth embodiment will be described. FIG. 12 is a perspective view of the terminal 1e according to the sixth embodiment before crimping. The terminal 1e has substantially the same configuration as the terminal 1d, but the form of the crimping portion 5 is different. The terminal 1e is different in that the wire holding portion 7a of the wire crimping portion 7 is tubular, and the conduction portion 7b of the wire crimping portion 7 and the covering crimping portion 9 are of an open barrel type. As described above, if at least a part of the conductor crimping portion 7 is a tubular shape closed in the circumferential direction, the other portion may be an open barrel type.

The terminal 1e can also be crimped in the same manner as the terminal 1 and the like. FIG. 13 is a plan view showing a terminal-attached electric wire 10a in which the terminal 1e and the coated lead wire 11 are crimped. In the terminal 1e, the tubular electric wire holding portion 7a, the open barrel type conductive portion 7b, and the coated crimping portion 9 are crimped to each portion of the coated conducting wire 11, respectively. At this time, as described above, the compressibility of the electric wire holding portion 7a is smaller than the compressibility of the conductive portion 7b.

Here, in the open barrel type conductive portion 7b and the covering crimping portion 9, at least a pair of barrel pieces facing each other are folded, and the conducting wire 13 and the covering portion 15 are crimped to each other. At this time, in the present embodiment, the barrel pieces facing each other are arranged in a staggered manner so as to be offset from each other in the axial direction of the crimping portion.

In this way, an open barrel type crimping portion having barrel pieces arranged in a staggered manner generally ensures that the barrel piece and the crimping target are firmly adhered to each other and crimped without damaging the crimping target. However, it has the characteristic that it is difficult to obtain high connection strength. Therefore, in the present embodiment, the electric wire holding portion 7a is formed into a tubular shape and strongly crimped to secure high connection strength, and the conductive portion 7b is made into a staggered open barrel type to damage the internal conducting wire 13. It is possible to surely secure the continuity with the conducting wire 13 without any problem.

In this way, by forming and crimping the electric wire holding portion 7a and the conductive portion 7b in the lead wire crimping portion 7, the same effect as that of the first embodiment can be obtained. In particular, by forming at least a part of the wire crimping portion 7 such as the wire holding portion 7a, which requires high connection strength, into a tubular shape closed in the circumferential direction, a high holding force can be obtained and the conductive portion 7b can be formed. By making it an open barrel type, the electrical resistance can be reduced.

The arrangement of at least one of the barrel pieces of the conductive portion 7b and the covering crimping portion 9 may be arranged at positions facing each other instead of being arranged in a staggered manner, and the barrel pieces may be crimped so as to wrap each other. In this case, the tips of the opposing barrel pieces are not abutted against each other, but the opposing barrel pieces are overlapped with each other, and one barrel piece is crimped so as to wrap the other barrel piece. As described above, the open barrel type crimping type is not particularly limited.

Various electric wires with terminals were prepared, and the electrical characteristics (electrical resistance), mechanical characteristics (connection strength), and manufacturing workability of the crimping part were evaluated. The electrical characteristics were evaluated by measuring the electrical resistance between the terminal and the coated conductor. As for the mechanical characteristics, the coated conductor was pulled from the terminal, and the tensile strength was measured by the load when the coated conductor was pulled out. In addition, the manufacturing workability was evaluated by the insertability when inserting the coated conductor into the terminal. The conditions and evaluation results are shown in Tables 1 to 4.

The cross-sectional area of the electric wire is the total cross-sectional area of the conductor. The number of strands is the number of conducting wires. As shown in FIGS. 3 (a) and 3 (b), a wire having a tensile strength “-” does not have a tensile strength, and a wire having a “with” has a cross section shown in FIG. 3 (c). As shown, it has a tensile strength body in the center and a conducting wire is arranged on the outer periphery of the tensile strength body. In each case, a wire made of a plurality of annealed copper twisted together was used.

As shown in FIG. 5C, the "circular compression" of the terminal processing unit compresses the lead wire from the outer circumference, and the "circular compression + batch plating" further forms a plating layer collectively from the outer circumference. Is.

The terminal shape "tubular split type" has the same shape as the terminal 1b shown in FIG. 9, and the "tubular integrated type" has the same shape as the terminal 1 shown in FIG. 4, and is a "tubular / open barrel type". Has the same form as the terminal 1c shown in FIG.

The crimping blade type is a blade type that crimps the conductor crimping part and the covering crimping part at the same time, and the one in which the conductor crimping part is "strong compression / weak compression (2 steps)" is as shown in FIG. It has two stages of lead wire crimping blades 32a and 32b, one of which is strongly compressed and the other (rear end side) is weakly compressed. On the other hand, in the case of "1 step", the wire crimping portion is crimped at a constant compression rate, and "weak compression", "medium compression", and "strong compression" are applied according to the compression rate. And said. The compression rate of 40% or more and less than 50% was defined as strong compression, the compression rate of 50% or more and less than 60% was defined as medium compression, and the compression rate of 60% or more and 90% or less was defined as weak compression.

The resistance value is the electrical resistance between the tip of the terminal and the rear end of the 100 mm long coated conductor. The tensile strength is the load when the coated conductor is pulled out from the terminal. As for the terminal insertability, the one in which the work of inserting the coated conductor into the crimping portion of the terminal was easy was marked with ◯, and the one with a little difficulty was marked with Δ.

As can be seen from Tables 1 to 3, in Examples 1 to 19 in which the conductor crimping portion was crimped in two stages, both the resistance value and the tensile strength could be achieved at the same time. For example, when the cross-sectional area of the conductor is 1.25 sq, the resistance value is 2 mΩ / 100 mm or less, and the tensile strength of 300 N or more can be secured. Further, when the cross-sectional area of the conductor was 0.35 sq, the resistance value was 10 mΩ / 100 mm or less, and the tensile strength of 70 N or more could be secured. Further, when the cross-sectional area of the conductor was 0.13 sq, the resistance value was 30 mΩ / 100 mm or less, and the tensile strength of 30 N or more could be secured. Further, when the cross-sectional area of the conductor was 0.08 sq, the resistance value was 50 mΩ / 100 mm or less, and the tensile strength of 30 N or more could be secured. Further, in the case of having a tensile strength body, the resistance value was 40 mΩ / 100 mm or less even at 0.05 sq, and the tensile strength of 60 N or more could be secured.

Further, in Examples 8 to 14 in which the coated crimping portion is an open barrel type, a conductor can be first arranged on the coated crimping portion from above, and then the conductor can be inserted into the tubular wire crimping portion. Therefore, the positioning of the conductor with respect to the crimping portion of the conductor was easy, and the insertability of the conductor into the terminal was good.

On the other hand, in Comparative Example 1 having a conductor cross-sectional area of 1.25 sq, the entire wire crimping portion was strongly compressed as compared with Examples 1 and 8, so that the resistance value was as high as 2.5 mΩ / 100 mm due to the breakage of the conductor. rice field. Further, in Comparative Example 2 having a conductor cross-sectional area of 0.3 sq, the entire conductor crimping portion was weakly compressed as compared with Examples 3 and 9, so that the holding force of the conductor was weak and the tensile strength was as low as 59N. .. Further, in Comparative Example 3 having a conductor cross-sectional area of 0.13 sq, the resistance value was as high as 34 mΩ / 100 mm because the entire conductor crimping portion was medium-compressed as compared with Examples 4, 11, 15, and 16. The tensile strength was as low as 19N. Further, in Comparative Examples 4 and 5 having a tensile strength body and having a conductor cross-sectional area of 0.05 sq, the entire conductor crimping portion was strongly compressed as compared with Examples 5 to 7, 12 to 14, so that the resistance value was 100 mΩ / It became as high as 100 mm or more.

In this way, by dividing the wire crimping portion into two parts, a wire holding portion and a conductive portion, and crimping them under different conditions, it is possible to satisfy the requirements of both electrical resistance and connection strength. It should be noted that the method of changing the compression ratio is not limited as long as the connection strength of the wire holding portion can be crimped so as to be higher than that of the conductive portion. For example, another method may be used, such as changing the cross-sectional shape of the wire crimping portion after crimping the wire holding portion.

Although the embodiments of the present invention have been described above with reference to the attached drawings, the technical scope of the present invention does not depend on the above-described embodiments. It is clear that a person skilled in the art can come up with various modifications or modifications within the scope of the technical ideas described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs to.

For example, in the above description, an example in which one layer of the conducting wire 13 is arranged on the outer periphery of the tensile strength body 17 is shown, but the arrangement of the conducting wire 13 is not limited to this. If the conductor 13 is arranged on the outer peripheral side of the tensile strength body 17, the conductor wire 13 may be arranged in two layers around the tensile strength body 17 as shown in FIG. 14 (a). As shown, the conductor 13 may be arranged in three layers around the tensile strength body 17. Further, the number of the conducting wires 13 may be 3 or more in the layer in contact with the tensile strength body 17 from the viewpoint of the conductivity and strength of the conducting wires 13 itself, and is preferably 20 or less. For example, as shown in FIGS. 5, 6, 14, 14 and the like, 12 lines or 14 lines may be used, and 6 lines or 8 lines may be used.

1, 1a, 1b, 1c, 1d, 1e ……… Terminal 3 ………… Terminal body 4 ………… Transition part 5 ………… Crimping part 7 ………… Conductor wire crimping part 7a ………… Wire holding part 7b …… ... Conduction part 9 ......... Covered crimping part 10, 10a ... Wire with terminal 11 ......... Covered conductor 13 ......... Conductor 15 ......... Covered part 17 ......... Tensile body 19 ......... Terminal processing part 21 ... …… Plating layer 31a ………… Upper blade type 31b ………… Lower blade type 32a, 32b ………… Conductor crimping blade type 34 ………… Covered crimping blade type

Claims (12)

An electric wire with a terminal that electrically connects the coated conductor and the terminal.
The terminal includes a wire crimping portion where a conductor exposed from a coated portion at the tip of the coated conductor is crimped, and a coated crimping portion where the coated portion of the coated conductor is crimped.
At least a part of the wire crimping portion is a tubular shape closed in the circumferential direction.
An electric wire holding portion is provided on the tip end side of the conducting wire crimping portion, and a conducting portion for obtaining continuity with the conducting wire is formed on the rear end side of the conducting wire crimping portion. Wires with terminals characterized by different compression rates. The electric wire with a terminal according to claim 1, wherein the compression rate in the electric wire holding portion is smaller than the compression rate in the conductive portion. The electric wire with a terminal according to claim 1 or 2, wherein the coated conductor is composed of a plurality of the conductors and at least one tensile strength body. The third aspect of claim 3, wherein the tensile strength body is located substantially at the center of the coated lead wire and the lead wire is arranged on the outer peripheral portion of the tensile strength body in a cross section perpendicular to the longitudinal direction of the coated lead wire. Electric wire with terminals. The electric wire with a terminal according to claim 4, wherein the conductor is twisted in the longitudinal direction of the coated conductor. 6. Wire with terminal. The invention according to any one of claims 1 to 6, wherein the conductor has a cross-sectional area of 0.35 sq or less, and the terminal can crimp the conductor having a cross-sectional area of 0.3 sq or less. Electric wire with terminals. The invention according to any one of claims 1 to 7, wherein the conductor has a cross-sectional area of 0.3 sq or less, and the terminal can crimp the conductor having a cross-sectional area of 0.3 sq or less. Electric wire with terminals. The electric wire with a terminal according to claim 1, wherein the compression rate in the coated crimping portion is smaller than the compression rate in the conductive portion. A wire harness comprising a plurality of electric wires with terminals including the electric wire with terminals according to any one of claims 1 to 9. A terminal that is electrically connected to a covered conductor
It is provided with a wire crimping portion in which a conductor exposed from a covering portion at the tip of the coated conductor is crimped, and a covering crimping portion in which the covering portion of the coated conductor is crimped.
At least a part of the wire crimping portion is a tubular shape closed in the circumferential direction.
An electric wire holding portion is provided on the tip end side of the conducting wire crimping portion, and a conducting portion for obtaining continuity with the conducting wire is formed on the rear end side of the conducting wire crimping portion. A terminal characterized by being divided. A terminal crimping blade type for manufacturing an electric wire with a terminal according to any one of claims 1 to 9.
Equipped with an upper blade type and a lower blade type,
The upper blade type and the lower blade type are formed so that both the portions corresponding to the lead wire crimping portion and the covering crimping portion have a substantially circular cross section when the terminals are crimped.
The terminal is characterized in that the distance between the upper blade type and the lower blade type of the portion corresponding to the electric wire holding portion is narrower than the distance between the upper blade type and the lower blade type of the portion corresponding to the conduction portion. Crimping blade type.

Images