JP5838939B2 - Electric wire with terminal - Google Patents

Description

  2. Description of the Related Art Conventionally, a terminal-attached electric wire in which an electric wire and a terminal are electrically connected by crimping a wire barrel formed on a terminal from the outside to a core wire exposed from the end of the electric wire is known.

  However, in an electric wire with a terminal, if an oxide film is formed on the surface of the core wire, there is a concern that the electrical resistance between the core wire and the terminal increases. In order to reduce the electrical resistance, it is conceivable to destroy the oxide film on the surface of the core wire by winding the barrel with a high pressure around the core wire. As a result, the oxide film formed on the surface of the core wire is torn and the new surface of the core wire is exposed, and the new surface and the terminal are in contact with each other.

  However, according to the above method, since the cross-sectional area of the core wire is greatly reduced, the mechanical strength, particularly the tensile strength against an impact load (more specifically, the strength with which the crimp terminal holds the electric wire) is lowered.

  In order to solve such a problem, in Patent Document 1, a difference in compression ratio with respect to the core wire of the barrel is given, and the electrical resistance between the electric wire and the terminal is reduced while ensuring the mechanical strength of the electric wire with terminal. Yes.

JP-A-2005-50736

  However, according to the technique described in Patent Document 1, the end portion on the connecting portion side of the barrel is pressed against the portion of the core wire that is disposed on the end portion on the connecting portion side of the barrel with a high compressive force. For this reason, the core wire extends and jumps out to the connection portion side, and there is a possibility that disconnection may occur when a large vibration is applied during use of the terminal-attached electric wire, and improvement has been demanded.

  The present invention has been completed on the basis of the above circumstances, and has a terminal-attached electric wire that achieves both good electrical performance and core wire holding power and can suppress a decrease in connection reliability due to disconnection. The purpose is to provide.

  The electric wire with a terminal of the present invention is crimped so as to be wound from the outside to an end portion of the core wire exposed at an end portion of the electric wire and an end portion of the electric wire, and an area near the end of the core wire is provided. A crimp member in which a thick portion larger in thickness than the thin portion is formed in a region opposite to the terminal side of the core wire than the thin portion, and an outer side of the core wire and the crimp member A terminal having a wire barrel portion to be crimped from, and in the core wire, a portion crimped by the thick portion and the wire barrel portion in the crimp member is a high compression portion, and the wire barrel portion A portion compressed by the thin-walled portion and the wire barrel portion in the crimping member alone is a low-compression portion that is compressed lower than the high-compression portion.

  According to such a configuration, in the high compression portion, the core wire is in a highly compressed state by the thickness of the thick portion. For this reason, the core wire and the thick portion are in sliding contact with each other, and the oxide film formed on the surface of the core wire is destroyed, and the new surface is exposed. The contact resistance between the core wire and the terminal can be reduced by the contact between the new surface and the wire barrel portion.

  On the other hand, in the low compression part, the holding force with respect to the electric wire (core wire) of a terminal can be improved because the core wire is made into the low compression state. In particular, the end portion of the core wire on the end side of the core wire is the place where the core wire is most likely to be broken, but since the compressive force on the core wire is reduced at this location, disconnection of the core wire is suppressed. In addition, even if the core wire is disconnected, because the compressive force on the core wire is reduced, the holding force on the core wire is increased, so the end of the broken core wire is detached from the wire barrel part and the counterpart device It is possible to prevent the connection reliability from being deteriorated by adhering to the connection part.

  The electric wire with terminal of the present invention is more preferably provided with the following configuration in addition to the above configuration.

  The thick portion may be arranged at a position closer to the end of the core wire than an end edge of the wire barrel portion opposite to the end of the core wire.

  According to such a structure, the low compression part will be formed in the both sides of the direction along the axial direction of a core wire on both sides of the high compression part in the part to which a wire barrel part is crimped | bonded in a core wire. Therefore, on both sides in the direction along the axial direction of the core wire with the high compression portion interposed therebetween, it is possible to increase the holding force of the terminal with respect to the electric wire (core wire), and to prevent a decrease in connection reliability due to disconnection.

  Further, the core wire includes a plurality of metal strands, and in the low compression portion, a compression rate defined by the following formula (1) is set to be greater than 50%, and in the high compression portion, The compression rate defined by the following formula (1) may be set smaller than 50%.

  Compression ratio = {(cross-sectional area of conductor after compression) / (cross-sectional area of conductor before compression)} × 100 (%) (1)

  According to such a configuration, the oxide film on the core wire can be destroyed by reducing the compression rate to less than 50% in the high compression portion. Thereby, the electrical resistance value of a core wire and a terminal can be made small. On the other hand, in the low compression portion, by making the compression ratio larger than 50%, it is possible to prevent the core wire from being cut and to secure a good electric wire holding force, and to prevent the connection reliability from being lowered due to the disconnection.

  The thick part may be formed by folding back the end of the crimping member opposite to the terminal side of the core wire so as to be doubled, and is opposed to the core wire in the crimping member. It may be formed by providing a protruding portion protruding on the side surface.

  ADVANTAGE OF THE INVENTION According to this invention, the electric wire with a terminal which can make favorable electrical performance and the retention strength of a core wire compatible, and can suppress the fall of the connection reliability by disconnection can be provided.

The side view of the electric wire with a terminal of Embodiment 1 The fragmentary sectional view of the electric wire with a terminal of Embodiment 1 Side view of crimping member of embodiment 1 The figure which looked at the crimping member of Embodiment 1 from back. The perspective view which shows a mode that the crimping member was wound around the core wire in Embodiment 1. In Embodiment 1, the side view which shows a mode that a terminal main body is crimped | bonded to the electric wire which wound the crimping member around the core wire. The fragmentary sectional view of the electric wire with a terminal of Embodiment 2 Side view of crimping member of embodiment 2 The figure which looked at the crimping member of Embodiment 2 from back. The perspective view which shows a mode that the crimping member was wound around the core wire in Embodiment 2.

<Embodiment 1>
Embodiment 1 of the present invention will be described with reference to FIGS. The electric wire 1 with a terminal of this embodiment is provided with the electric wire 10 and the terminal 20 crimped | bonded to the core wire 11 exposed from the edge part of this electric wire 10, as shown in FIG. In the following description, the direction along the axial direction of the electric wire 10 in the electric wire with terminal 1 will be referred to as the front-rear direction, the side attached to the device or the like will be described as the front side, and the side to which the electric wire 10 is connected will be described as the rear side.

[Configuration of terminals and wires]
(Wire 10)
The electric wire 10 includes a core wire 11 formed by twisting a plurality of metal strands 13 and an insulating coating 12 made of a synthetic resin that covers the outer periphery of the core wire 11. The core wire 11 can use arbitrary metals as needed, such as aluminum, an aluminum alloy, copper, a copper alloy. In the present embodiment, a plurality of metal strands made of aluminum or aluminum alloy are used as the strands 13. At the end of the electric wire 10, the core wire 11 is exposed by peeling off the insulating coating 12.

(Terminal 20)
The terminal 20 is a so-called LA terminal, and includes a terminal main body 21 and a crimping member 28 formed separately from the terminal main body 21. The terminal main body 21 and the crimping member 28 are formed by stamping a metal plate into a predetermined shape and pressing each into a predetermined shape. As the plate material, for example, a metal material such as copper, copper alloy, aluminum, aluminum alloy, iron, or iron alloy is used. The plate material may be plated with tin, nickel, or the like as necessary.

  The terminal body 21 includes a wire barrel portion 22 that is formed in a plate shape extending along the circumferential direction of the electric wire 10 and is crimped to the core wire 11 exposed from the insulating coating 12.

  From the rear end edge of the wire barrel part 22, the rear side extension part 23 is extended toward the back from the center position of the left-right direction. An insulation barrel portion 24 is formed at the rear end portion. The insulation barrel portion 24 extends from the both side edges of the rear end portion of the rear side extension portion 23 toward the sides, and is formed in a plate shape that is elongated in the direction along the circumferential direction of the electric wire 10 as a whole. Yes.

  From the front end edge of the wire barrel part 22, the front extension part 25 formed in the elongate plate shape is extended toward the front from the center position of the left-right direction. A connecting portion 26 that is fixed to a device or the like is formed at the front end edge of the front side extending portion 25. The connection portion 26 is formed by penetrating a bolt hole in a central portion of a rectangular plate material.

  The crimping member 28 is used by being wound around the core wire 11 exposed at the end of the electric wire 10, and is formed in an elongated plate shape from the same or different metal as the metal constituting the terminal body 21. The length dimension of the crimping member 28 is set to a length that can surround the outer periphery of the core wire 11. In the state where the crimping member 28 is wound around the core wire 11, an end edge portion on the rear side (the side opposite to the terminal side of the core wire 11) is folded and overlapped on the contact surface side with the core wire 11. Thereby, in the crimping member 28, a portion that is doubled by folding is a thick portion 29 having a large thickness, and a portion that is not doubled is a thin portion 30 having a small thickness. ing.

  On the outer peripheral surface (the surface opposite to the side facing the core wire 11) of the crimp member 28, two groove portions 31 capable of visually confirming the position with respect to the wire barrel portion 22 are provided.

  Each groove portion 31 extends in a direction along the circumferential direction of the electric wire 10 in a state where the crimping member 28 is wound around the core wire 11. The two groove portions 31 are provided in parallel in the direction along the axial direction of the electric wire 10. Hereinafter, of the two groove portions 31, the one provided on the front side (side closer to the terminal side of the core wire 11) in a state where the crimping member 28 is wound around the core wire 11 is the first groove portion 31 </ b> A and the rear side (the core wire 11). The one provided on the side far from the terminal side is referred to as a second groove portion 31B.

  The first groove portion 31 </ b> A is formed in the thin-walled portion 30 and is disposed slightly rearward from the front end edge of the crimping member 28. Further, the second groove portion 31 </ b> B is placed at the same position as the front end edge of the thick portion 29, and is disposed at a front side position. In the crimping member 28, the length from the rear edge to the first groove portion 31 </ b> A is shorter than the length of the wire barrel portion 22 in the direction along the axial direction of the electric wire 10.

[Assembly of electric wire with terminal]
In order to assemble the electric wire with terminal 1, first, the crimping member 28 is wound around the core wire 11 exposed at the end of the electric wire 10. At this time, the side where the thick portion 29 is formed in the crimping member 28 is set to be the rear side (the side opposite to the terminal side of the core wire 11).

  Next, the electric wire 10 around which the crimping member 28 is wound is placed on the terminal main body 21. At this time, a portion of the electric wire 10 where the crimping member 28 is wound around the core wire 11 is overlapped with the wire barrel portion 22, and a portion where the core wire 11 is covered with the insulating coating 12 is overlapped with the insulation barrel portion 24. .

  Of the two groove portions 31 provided on the crimping member 28, the wire groove portion 31 </ b> A is exposed to the front side from the wire barrel portion 22 and the second groove portion 31 </ b> B is covered by the wire barrel portion 22. The crimping member 28 is positioned with respect to 22.

  Thereby, the thin part 30 protrudes forward in the axial direction of the electric wire 10 from the front edge (connection part 26 side) of the wire barrel part 22, and is a part closer to the thick part 29 than that. Is covered by the wire barrel portion 22. The thick part 29 is completely covered by the wire barrel part 22. In addition, the rear end edge of the crimping member 28 is positioned slightly forward (on the end side of the core wire 11) in the wire barrel portion 22 from the end portion on the rear side (insulation barrel portion 24 side). In the crimping member 28, a portion protruding from the end edge of the wire barrel portion 22 is a protruding portion 30 </ b> A. Further, the tip of the core wire 11 slightly protrudes from the tip of the protrusion 30A.

  In this state, the wire barrel part 22 and the insulation barrel part 24 are caulked to the electric wire 10 with a jig. As a result, the wire barrel portion 22 is bent and pressure-bonded so as to be wound around the core wire 11 and the pressure-bonding member 28 and the insulation barrel portion 24 is wound around the insulating coating 12.

  Thus, since the crimping member 28 is overlapped on a part of the wire barrel portion 22, the core wire 11 is in a state where the compression rate differs depending on the position in the wire barrel portion 22. That is, in the rear region of the wire barrel portion 22, the core wire 11 is compressed around the wire barrel portion 22 alone, and thus is in a low compression state (hereinafter referred to as “first low compression portion 32”). say).

  The compression rate is defined as {(cross-sectional area of the conductor after compression) / (cross-sectional area of the conductor before compression)} × 100 (%). Low compression means that the compression rate shows a large value, and high compression means that the compression rate shows a small value.

  On the other hand, in the front region of the wire barrel part 22, the core wire 11 is crimped by the wire barrel part 22 and the crimping member 28. In particular, in the region where the thick portion 29 is formed in the crimping member 28, the core wire 11 is in a highly compressed state by the thickness of the thick portion 29 (hereinafter referred to as “high compression portion 33”). say). On the other hand, in the region of the crimping member 28 that is the thin-walled portion 30, the core wire 11 is in a higher compression state than the first low compression portion 32, but is in a lower compression state than the high compression portion 33. (Hereinafter referred to as “second low compression section 34”).

  Thus, the high compression part 33 is formed in the center position about the axial direction of the electric wire 10 in the part to which the wire barrel part 22 is crimped in the core wire 11, and the first low compression part is located behind the high compression part 33. 32 and the second low compression portion 34 is formed on the front side.

  And in the high compression part 33, the core wire 11 is compressed by the thick part 29 and the wire barrel part 22 of the crimping | compression-bonding member 28, and it is set as a highly compressed state. As a result, the core wire 11 and the thick portion 29 are in sliding contact with each other, and the oxide film formed on the surface of the core wire 11 is destroyed, and the new metal surface is exposed. When this new surface comes into contact with the wire barrel portion 22, the contact resistance between the core wire 11 and the terminal 20 can be reduced.

  On the other hand, of the two low compression portions 32 and 34, the first low compression portion 32 on the rear side is low compression, so that the holding force of the terminal 20 with respect to the electric wire 10 (core wire 11) can be increased. .

  The second low compression portion 34 is formed at the end of the wire barrel portion 22 on the connection portion 26 side. Here, in the wire barrel part 22, the end part on the connection part 26 side, that is, the end part on the terminal side of the core wire 11 is a place where the core wire 11 is most likely to be broken, but the compressive force on the core wire 11 is small in this place. Therefore, disconnection of the core wire 11 is suppressed. In addition, even if the core wire 11 is disconnected, since the holding force for the core wire 11 is increased by reducing the compressive force on the core wire 11, the end of the broken core wire 11 is removed from the wire barrel portion 22. It is prevented that it comes off and adheres to the connection part 26 and decreases the connection reliability with the counterpart device or the like.

  The compression rate of the core wire 11 in the high compression portion 33 is preferably 50% or less, and 35% or less in order to destroy the oxide film on the surface of the core wire 11 and to ensure good electrical performance with low electrical resistance. More preferably, it is more preferably 25% or less, and particularly preferably 20% or less.

  The oxide film of the core wire 11 can be destroyed by setting the compression rate to 50% or less. Thereby, the electrical resistance value of the core wire 11 and the terminal 20 can be made small. If the compression rate is 35% or less, the surfaces of the strands 13 constituting the core wire 11 are microscopically adhered to each other, so that the electrical resistance value can be reduced. Furthermore, when the compression rate is 25% or less, the strands 13 adhere macroscopically, so that the electrical resistance value can be further reduced. Furthermore, when the compression ratio is 20% or less, the strands 13 can be reliably adhered to each other, so that the electrical resistance value can be reliably reduced.

  Moreover, the compression rate of the core wire 11 in the first low compression portion 32 and the second low compression portion 34 is more than 50% in order to prevent the core wire 11 from being cut and to secure a good electric wire 10 (core wire 11) holding force. It is preferably large, more preferably 60 to 90%, and particularly preferably 70 to 80%.

  A part of the crimping member 28 (projecting part 30A) is arranged so as to project forward from the front end edge of the wire barrel part 22, and the tip part of the core wire 11 slightly projects from the tip of the projecting part 30A. Has been. By doing in this way, when the wire barrel part 22 is crimped, the core wire 11 which protrudes from the edge of the wire barrel part 22 will be in the state crimped | bonded by the protrusion part 30A of the crimping | compression-bonding member 28. Thereby, it can suppress that the core wire 11 bulges from the edge of the wire barrel part 22 with the pressure added to the wire barrel part 22. FIG. As a result, it can suppress that the core wire 11 contacts and short-circuits members other than the terminal 20. When the core wire 11 is highly compressed in the high compression portion 33, the core wire 11 is easily swelled from the wire barrel portion 22, and thus such a configuration is particularly effective.

  As described above, according to the present embodiment, the terminal-attached electric wire 1 is crimped so as to be wound from the outside around the electric wire 10 including the core wire 11 and the end portion of the core wire 11 exposed at the end portion of the electric wire 10. And the area | region near the terminal of the core wire 11 is made into the thin part 30, and the thick part 29 larger in thickness than the thin part 30 is formed in the area opposite to the terminal side of the core wire 11 from the thin part 30. The formed crimp member 28, and the terminal 20 provided with the wire barrel part 22 crimped | bonded to the core wire 11 and the crimp member 28 from the outside are provided. And in the core wire 11, the part crimped | bonded by the thick part 29 and the wire barrel part 22 in the crimping | compression-bonding member 28 is made into the high compression part 33, and only the wire barrel part 22 or the thin part 30 in the crimping member 28, and the said The parts compressed with the wire barrel portion 22 are the low compression portions 32 and 34 that are lower in compression than the high compression portion 33.

  According to such a configuration, in the high compression portion 33, the core wire 11 is highly compressed by the thickness of the thick portion 29. For this reason, the core wire 11 and the thick portion 29 are in sliding contact with each other, the oxide film formed on the surface of the core wire 11 is destroyed, and the new surface is exposed. The contact resistance between the core wire 11 and the terminal 20 can be reduced by the contact between the new surface and the wire barrel portion 22.

  On the other hand, in the two low compression parts 32 and 34, the holding force with respect to the electric wire 10 (core wire 11) of the terminal 20 can be raised because the core wire 11 is made into the low compression state. In particular, the end of the core wire 11 on the end side of the core wire 11 in the wire barrel portion 22 is the place where the core wire is most likely to be cut off. However, since the compressive force on the core wire 11 is reduced at this location, disconnection of the core wire 11 is suppressed. The In addition, even if the core wire 11 is disconnected, since the holding force for the core wire 11 is increased by reducing the compressive force on the core wire 11, the end of the broken core wire 11 is removed from the wire barrel portion 22. It is prevented that it comes off and adheres to the connection part 26 and the like, thereby reducing the connection reliability with the counterpart device.

  Further, the thick portion 29 is arranged at a position closer to the end of the core wire 11 than the end of the wire barrel portion 22 opposite to the end of the core wire 11.

  According to such a configuration, the first low compression portion 32 and the first low compression portion 32 on both sides in the direction along the axial direction of the core wire 11 with the high compression portion 33 sandwiched between the portions of the core wire 11 to which the wire barrel portion 22 is crimped. 2 low compression parts 34 will be formed, respectively. Therefore, on both sides of the direction along the axial direction of the core wire 11 across the high compression portion 33, the holding force of the terminal 20 with respect to the electric wire 10 (core wire 11) is increased, and the decrease in connection reliability due to disconnection is prevented. Can do.

  Further, the core wire 11 includes a plurality of metal strands 13, and the compression ratio defined by the following formula (1) is set to be larger than 50% in the two low compression portions 32 and 34, In the high compression part 33, the compression rate defined by following formula (1) may be set smaller than 50%.

  Compression ratio = {(cross-sectional area of conductor after compression) / (cross-sectional area of conductor before compression)} × 100 (%) (1)

  According to such a structure, in the high compression part 33, the oxide film of the core wire 11 can be destroyed by making a compression rate smaller than 50%. Thereby, the electrical resistance value of the core wire 11 and the terminal 20 can be made small. On the other hand, in the low compression parts 32 and 34, a favorable electric wire holding force is ensured by making a compression rate larger than 50%, and the fall of the connection reliability by disconnection can be prevented.

<Embodiment 2>
Next, Embodiment 2 of the present invention will be described with reference to FIGS. The electric wire with terminal 40 of the present embodiment is different from the first embodiment in the structure of the crimping member 41. In addition, since it is the same as that of Embodiment 1 except the structure of the crimping | compression-bonding member 41, the same code | symbol is attached | subjected and description is abbreviate | omitted.

  The crimping member 41 is used by being wound around the core wire 11 exposed at the end of the electric wire 10, and is formed in an elongated plate shape from the same or different metal as the metal constituting the terminal body 21. The crimping member 41 is a protrusion protruding toward the contact surface with the core wire 11 at a position slightly ahead of the rear edge (opposite to the terminal side of the core wire 11) in a state of being wound around the core wire 11. 42 is provided. The protrusion 42 has a long and narrow stripe shape in the direction along the circumferential direction of the core wire 11, and is provided over the entire width in the direction along the circumferential direction of the core wire 11. In the crimping member 41, the region where the protrusion 42 is provided is a thick portion 43 having a large thickness, and the other portion where the protrusion 42 is not provided is a thin portion 44 having a small thickness. Yes.

  On the outer peripheral surface of the crimping member 41 (the surface opposite to the side facing the core wire 11), as in the first embodiment, two grooves 31A that can visually confirm the position with respect to the wire barrel portion 22, 31B is provided.

  Also in the present embodiment, in the region on the rear side in the wire barrel portion 22, the core wire 11 is compressed around the wire barrel portion 22 only, and thus is in a low compression state (first low compression portion 45). ). On the other hand, in the front region of the wire barrel portion 22, the core wire 11 is crimped by the wire barrel portion 22 and the crimping member 41. In particular, in the region where the thick portion 43 is formed in the crimping member 41, the core wire 11 is in a highly compressed state by the thickness of the thick portion 43 (high compression portion 46). On the other hand, in the region of the crimping member 41 that is the thin-walled portion 44, the core wire 11 is in a higher compression state than the first low compression portion 45, but is in a lower compression state than the high compression portion 46. (Second low compression section 47). Thereby, the same effect as Embodiment 1 is produced.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the above embodiment, the core wire 11 is a stranded wire formed by twisting a plurality of strands 13, but is not limited thereto, and may be a single core wire made of a metal bar.

(2) In the present embodiment, the terminal 20 is an LA terminal. However, the terminal 20 is not limited to this, and may be a terminal having an arbitrary shape such as a male terminal or a female terminal.

DESCRIPTION OF SYMBOLS 1, 40 ... Electric wire with terminal 10 ... Electric wire 11 ... Core wire 13 ... Elementary wire 20 ... Terminal 22 ... Wire barrel part 28, 41 ... Crimp member 29, 43 ... Thick part 30, 44 ... Thin part 32, 45 ... 1st Low compression part 33, 46 ... High compression part 34, 47 ... Second low compression part 42 ... Projection

Claims (5)

An electric wire with a core wire;
The wire is crimped so as to be wound from the outside around the end portion of the core wire exposed at the end portion of the electric wire, and a region closer to the end of the core wire is a thin portion, and the end of the core wire is more than the thin portion. A crimping member in which a thick portion thicker than the thin portion is formed in a region opposite to the side;
A terminal having a wire barrel portion that is crimped to the core wire and the crimp member from the outside, and
In the core wire, a portion crimped by the thick portion and the wire barrel portion in the crimp member is a high compression portion, and only the wire barrel portion or the thin portion and the wire barrel portion in the crimp member. The electric wire with a terminal which is what was made into the low compression part by which the part crimped | compressed by and was made into low compression rather than the said high compression part.   The electric wire with a terminal according to claim 1, wherein the thick wall portion is arranged at a position closer to the end of the core wire than an end edge on the opposite side of the end of the core wire in the wire barrel portion. The core wire includes a plurality of metal strands,
In the low compression part, the compression rate defined by the following formula (1) is set to be larger than 50%,
The electric wire with a terminal according to claim 1 or 2, wherein a compression rate defined by the following formula (1) is set to be smaller than 50% in the high compression portion.
Compression ratio = {(cross-sectional area of conductor after compression) / (cross-sectional area of conductor before compression)} × 100 (%) (1)   The said thick part is formed in the said crimping | compression-bonding member by making the edge part on the opposite side to the terminal side of the said core wire into a double by folding. Electric wire with terminal as described in 2.   The terminal according to any one of claims 1 to 3, wherein the thick portion is formed by providing a protruding portion protruding on a surface of the crimping member facing the core wire. With electric wire.

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