JP2003243057A - Terminal for connection of electric wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connecting terminal for aluminum electric wire whereby electric connection can be established while the oxide coating film formed on the surface of the aluminum core wire is broken. <P>SOLUTION: The electric wire connecting terminal is equipped with a pressure attachment part to attach by pressure the core wire of an aluminum electric wire, wherein the pressure attachment part is furnished with a pair of pressure attaching pieces formed upright confronting on the left and right of the base bottom part which receives the aluminum core wire, and the inner surface(s) of the base bottom part and/or attaching pieces is provided with a rough surface portion capable of shaving off the oxide coating film from the core wire. At the time of pressure attaching, the rough surface portion shaves off the oxide coating film, breaks and removes. In this area, the rough surface portion of the pressure attaching part is put in electric contact with the clean surface of the core wire, so that it is possible to establish electric connection while the oxide coating film is broken efficiently at the same time as connection of the terminal with the core wire of the aluminum electric wire. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric wire connecting terminal, and more particularly to an electric wire connecting terminal suitable for connection with an aluminum electric wire.

[0002]

2. Description of the Related Art Conventionally, in electric power fields such as power plants and overhead transmission lines, aluminum electric wires having a core made of an aluminum material have been used as electric power lines because they are lightweight and have excellent electric conductivity. Generally, when a wire is used for wiring to various electric devices and the like, a wire connecting terminal is attached to a terminal portion of the wire, and the wire connecting terminal applied to the aluminum wire is, for example, shown in FIG. Things are known.

As shown in FIG. 7, the wire connecting terminal 50 is
It is integrally formed from a metal material such as aluminum or aluminum alloy. This wire connection terminal 50 has a fastening portion 52 having a through hole 51 formed at its tip through which a fastening means (not shown) such as a bolt can be passed, and at the base end, a jacket 54 of the end portion of the aluminum wire 53. Has a crimping portion 56 for crimping the exposed aluminum core wire portion 55.

FIG. 8 is a top view of this wire connecting terminal, and FIG. 9 is a sectional view taken along line AA and B of FIG.
-B is a cross section. As shown in these drawings, a plurality of groove portions 57 are formed on the inner side surface and the bottom surface of the crimp portion 56 in a direction orthogonal to the length direction of the aluminum core wire portion 55 to be crimped. The groove portion 57 is for preventing the aluminum core wire 55 from coming off when the aluminum electric wire 53 crimped to the crimp portion 56 receives a tensile force in the longitudinal direction.

In crimping the aluminum electric wire 53 to the electric wire connecting terminal 50 having the above-mentioned structure, the aluminum core wire portion 55 is arranged on the bottom surface of the crimping portion 56, and then the crimping portion 56 is swaged by a tool not shown. Done. As a result, the electric wire connection terminal 50 and the aluminum electric wire 53 are inseparably crimped. On the other hand, in fastening and electrically connecting the fastening portion 52 to various electric devices and the like, a fastening means such as a bolt is passed through the through hole 51 and the fastening means is fastened and fixed to a connected portion of various electric devices and the like. It is done by doing. As a result, the aluminum electric wire 53 and various electric devices are electrically connected via the electric wire connecting terminal 50.

[0006]

In the field of electric power mentioned above, in the fields of automobiles, OA equipment, home appliances, etc., copper having a core wire made of a copper-based material that is low in cost and excellent in electrical conductivity is used. The electric wire is used as a signal line.

Particularly in the field of automobiles, since the performance and performance of vehicles have been rapidly advanced, the copper electric wires used have been increased with the increase of various electric equipments and control equipments mounted on vehicles. The current situation is that the number is increasing.
In addition, recently, development of electric vehicles and fuel cell vehicles, which have a low impact on the environment, has been actively conducted, and in this type of vehicles, it is necessary to take out large electric energy from batteries, fuel cells, etc. As electric wires connected to these, electric power lines having a diameter larger than that of conventional signal lines are required.

Under such circumstances, when it is attempted to improve the fuel efficiency by reducing the weight of the vehicle, the total weight of the electric wires used per vehicle will not be ridiculous and should be neglected. It is not the weight that can be done. In particular,
In electric vehicles, fuel cell vehicles, etc., which are expected to become popular in the near future, since the batteries, fuel cells, etc. mounted on the vehicles themselves are heavy, there is a strong demand to make the vehicles as light as possible. Therefore, for the purpose of further weight reduction, an aluminum electric wire using aluminum whose core wire has a density of about one-third as compared with copper has recently attracted particular attention in the automobile field (copper density 8 0.96 g / cm
^In contrast to ^three , the density of aluminum is 2.70 g / cm ³ ).

However, although the aluminum electric wire itself has already been used in the electric power field such as an overhead power transmission line as described above, it has not been particularly necessary in the automobile field until now, so that it is not widely used. However, if the aluminum electric wire is used for an automobile, the following problems will occur.

That is, since aluminum is very active, when the outer coat of the end portion of the aluminum electric wire is peeled off to expose the aluminum core wire portion, the surface is exposed to the outside air and is oxidized, and is made of aluminum oxide. An oxide film is formed.
This oxide film is extremely thin, about 100 Å or less, but it is dense and hard (passive state, mechanically strong), and
Since it is insulating, the electrical resistance increases when the electrical connection is made while the aluminum core wire portion and the wire connection terminal are interposed.

Therefore, in order to avoid this problem in the above-mentioned electric power field and the like, an operator or the like previously uses an oxide film on the aluminum core wire portion with a wire brush or the like immediately before connecting the aluminum electric wire and the electric wire connecting terminal. It is generally performed by mechanically destroying / removing. This is because, in the case of the conventional wire connecting terminal, the dense and hard oxide film formed on the aluminum core wire portion cannot be destroyed by simply crimping the crimp portion.

However, if this kind of work is carried out in the field of automobiles which uses a large number of electric wires, not only is the efficiency extremely low, but the productivity is deteriorated. In addition, the amount of oxide film removed may not be constant due to differences in operators, and there may be a problem that variations in electrical connection become large.

Therefore, the problem to be solved by the present invention is as follows.
An object of the present invention is to provide an electric wire connection terminal that can be electrically connected while destroying an oxide film formed on the surface of an aluminum core portion of an aluminum electric wire.

[0014]

In order to solve this problem, an electric wire connecting terminal according to the present invention is an electric wire provided with a crimping portion for crimping an aluminum core wire portion of an aluminum electric wire as described in claim 1. In the connection terminal, the crimp portion includes a crimp piece formed of a pair of standing uprights on the left and right of a base portion that receives the aluminum core wire portion, and the inner surface of the base portion and / or the left and right crimp pieces. The gist of the present invention is that a rough surface portion capable of scraping off the oxide film formed on the surface of the aluminum core wire portion to be crimped is formed.

According to the electric wire connecting terminal having the above structure,
On the base of the crimp section and / or the inner surface of the left and right crimp pieces,
Oxide film formed on the surface of the aluminum core (in the passive state,
Since the rough surface portion that can be mechanically hardened) is formed, the oxide film formed on the surface of the aluminum core wire portion is scraped off by the rough surface portion at the time of pressure bonding, and is destroyed and removed. Then, at that portion, the rough surface portion of the crimping portion and the exposed clean surface of the aluminum core wire portion electrically contact with each other. Therefore, it becomes possible to connect the wire connecting terminal to the aluminum core wire portion of the aluminum wire and at the same time, to electrically connect while efficiently destroying the oxide film.

In this case, it is preferable that the rough surface portion is a cone-shaped protrusion formed on the inner surface of the base portion and / or the left and right crimping pieces.

When the rough surface portion of the crimping portion is a cone-shaped projection formed on the inner surface of the base portion and / or the left and right crimping pieces, this projection bites into the oxide film during crimping. As a result, the oxide film is scraped off, destroyed and removed. At this time, the cone shape is not particularly limited, but it is preferably a polygonal cone shape. This is because the polygonal pyramid shape has the ridge portion, and thus easily penetrates into the oxide film. It is preferable that the shape is a triangular pyramid or a quadrangular pyramid having a relatively simple shape and good biting force.

Further, as described in claim 3, the rough surface portion is a raised portion formed by punching an inner surface of the base portion and / or the left and right crimping pieces from the outer side to the inner side. Is also good.

When the rough surface portion of the crimping portion is a raised portion formed by punching the inner surface of the base portion and / or the left and right crimping pieces from the outer side to the inner side, this raised portion is formed at the time of crimping. The oxide bites into the oxide film, so that the oxide film is scraped off, destroyed, and removed. In this case, since the raised portion can be formed by stamping, the rough surface portion can be easily formed.

Further, as described in claim 4, the rough surface portion may be a hardened layer formed by hitting a shot by shot peening to the inner surface of the base portion and / or the left and right pressure-bonded pieces. good.

When the rough surface portion of the pressure-bonded portion is a hardened layer formed by shot shot peening hitting the inner surface of the base portion and / or the left and right pressure-bonded pieces,
The hardened layer bites into the oxide film during pressure bonding, whereby the oxide film is scraped off, destroyed, and removed. In addition, since the hardened layer has innumerable irregularities formed by dents by shots, the surface area is increased, and the number of electrically favorable contact portions can be increased. Therefore, there is also an advantage that a contact resistance is small and a highly reliable connection is easily obtained.

Further, according to a fifth aspect of the present invention, in the rough surface portion, powder having a hardness equal to or higher than that of the oxide film is fixed to the inner surface of the base portion and / or the left and right crimping pieces. It may be a powder layer formed by

In the case where the rough surface portion of the pressure-bonded portion is a powder layer formed by bonding powder having hardness equal to or higher than that of the oxide film to the base portion and / or the inner surface of the left and right pressure-bonded pieces. In the case of the pressure bonding, the adhered powder bites into the oxide film, so that the oxide film is scraped off, destroyed and removed. In this case, it is very easy to form the rough surface portion, and it is possible to share the parts with the wire connection terminal having no rough surface portion in the crimp portion.

Further, as described in claim 6, the rough surface portion may be a sprayed layer formed by spraying a metal on the inner surface of the base portion and / or the left and right crimping pieces.

When the rough surface portion of the pressure-bonded portion is a thermal sprayed layer formed by spraying a metal on the inner surface of the base portion and / or the left and right pressure-bonded pieces, the uneven surface due to this thermal sprayed layer is formed during the pressure bonding. By cutting into the oxide film, the oxide film is scraped off, destroyed, and removed.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION An electric wire connecting terminal according to an embodiment of the present invention will be described in detail below with reference to the drawings. It should be noted that the connection side with the unillustrated mating side connected portion will be described as the front side.

FIG. 1 is an external perspective view showing an electric wire connecting terminal provided with a crimp portion having a rough surface portion. As shown in FIG. 1, the wire connection terminal 10 is made of a metal material such as aluminum, aluminum alloy, copper, copper alloy, brass, etc. Crimping portion 14 for crimping the aluminum core wire portion 13 of the aluminum electric wire 12 to the base end while having the fastening portion 11 as a member
Is equipped with.

The fastening portion 11 has a substantially circular outer shape, and a through hole 15 is formed in the center thereof so that a fastening means (not shown) such as a bolt can be passed through the through hole 15. It is possible to pierce and fasten the fastening means to the mating side connected portion.

On the other hand, the crimping portion 14 is provided with a base portion 17 for receiving the aluminum core wire portion 13 exposed by peeling off the outer sheath 16 of the end portion of the aluminum electric wire 12, and the base portion 17 has a pair of right and left sides. Crimping pieces 18a and 18b made of are erected so as to face each other. Then, the oxide film (in the passive state and mechanically strong) formed on the surface of the aluminum core wire portion 13 can be scraped off on the inner surface of the base portion 17 of the crimp portion 14 and the left and right crimp pieces 18a, 18b. Rough surface portion 19 (in FIG. 1,
The hatched portion) is formed.

Specific examples of the rough surface portion 19 of the electric wire connecting terminal according to the embodiment of the present invention include a protrusion, a ridge, a shot peening hardening layer, a powder layer, and a metal spray layer. The respective structures of the rough surface portions 19 will be described below. 2 to 6 shown below are rough surface portions 19 (hatched portions) of the crimp portion 14 in FIG.
Is an enlarged view of.

First, FIG. 2 is an external perspective view showing a protrusion as a rough surface. As shown in FIG.
The outer shape is a triangular pyramid shape, and a plurality of files are formed on the inner surface of the base portion 17 and the left and right crimping pieces 18a and 18b of the crimping portion 14 in the shape of a file.
It is possible to scrape off the oxide film formed on the surface of the aluminum core wire portion 13 by the ridge line portion 21 (including the tip end portion) thereof.

Here, the shape of the protrusion 20 is not limited to the triangular pyramid shape, and may be another pyramid shape. It is preferable that the shape is a triangular pyramid or a quadrangular pyramid, from the viewpoint that it can be formed with a relatively simple shape and is easy to form, and that it has a good biting force with respect to the oxide film.

Next, FIG. 3 is an external perspective view showing a raised portion as a rough surface portion. As shown in FIG.
Is formed by punching the inner surfaces of the base portion 17 and the left and right crimping pieces 18a, 18b from the outer side to the inner side.

As a method of forming the raised portion 22, specifically, after the notch 23 is formed in the surface of the base portion 17 and the left and right crimping pieces 18a, 18b, this portion is cut into the base portion 17 and the left and right crimping pieces 18a, 18b. It can be formed by punching from the outside of 18b toward the inside and plastically deforming it.

Next, FIG. 4 is a sectional view showing a state of forming a hardened layer as a rough surface portion by shot peening and a hardened layer formed by the hardened layer. As shown in FIG. 4 (b), the hardened layer 24 has an innumerable number of shots 25.
.. by being struck at high speed (Fig. 4 (a)
), The surface hardness of the base portion 17 and the left and right crimping pieces 18a, 18b are increased by work hardening. Further, on the surface of the hardened layer 24, shots 25 ...
Innumerable irregularities 26 formed by the dents are formed.

Next, FIG. 5 is a sectional view showing a powder layer as a rough surface portion formed by fixing powder. As shown in FIG. 5, the powder layer 27 is equal to or more than the oxide film formed on the surface of the aluminum core wire portion 13 on the inner surface of the base portion 17 of the crimp portion 14 and the left and right crimp pieces 18a, 18b. The powder 28 having the hardness of (hereinafter referred to as "hard powder") is fixedly formed.

As a method for forming the powder layer 27, specifically, the base portion 17 and the left and right crimping pieces 18 of the crimping portion 14 are formed.
For example, a suspension of hard powder 28 in an organic solvent that is volatile at room temperature is applied to the inner surfaces of a and 18b, or the hard powder 28 is mixed with a synthetic resin to form a paste. It can be formed by applying a substance or by applying a mixture of hard powder 28 to a paint,
The hard powder 28 is the base 17 and / or the left and right crimping pieces 18.
The fixing method is not particularly limited as long as it is fixed to the inner surfaces of a and 18b.

Next, FIG. 6 is a sectional view showing a state of forming a thermal sprayed layer as a rough surface portion by thermal spraying of metal and the thermal sprayed layer formed thereby. Here, examples of the metal sprayed in the present application include Sn and the like. Figure 6 (a)
As shown in (b), the sprayed layer 29 is formed on the inner surface of the base portion 17 of the pressure-bonding portion 14 and the left and right pressure-bonding pieces 18a, 18b.
Sn31 is sprayed and formed by the spraying device 30.

Next, the electric wire connecting terminal 10 having the above structure
The function and effect obtained when the aluminum core wire portion 13 of the aluminum electric wire 12 is crimped to the crimp portion 14 will be described. After arranging the aluminum core wire portion 13 on the base portion 17 of the wire connection terminal 10, the crimping pieces 18a, 1
Insert 8b and tighten. At this time, the base portion 17 of the crimping portion 14 and the inner surfaces of the left and right crimping pieces 18a, 18b are formed of the above-mentioned protrusions 20, ridges 22, hardened layer 24, powder layer 27, thermal spray layer 29, and the like. Since the surface portion 19 is formed, the oxide film formed on the surface of the aluminum core wire portion 13 is scraped off by the rough surface portion 19 and is pressed while being broken and removed. The rough surface portion 19 of the crimp portion 14
Then, the conductive surface is electrically contacted with the clean surface of the aluminum core wire portion 13 exposed by scraping off the oxide film, so that the conductive state becomes good.

According to the above-mentioned electric wire connecting terminal, since the electric wire connecting terminal can be connected to the aluminum core portion of the aluminum electric wire, and at the same time, the oxide film can be efficiently destroyed and electrically connected, the electric wire connecting terminal can be connected to the aluminum electric wire. Immediately before connecting the terminals, it is not necessary for the worker to mechanically break and remove the oxide film on the aluminum core wire portion beforehand by using a wire brush or the like, and it is possible to improve the productivity. Become.

Although the embodiments of the present invention have been described above, the electric wire connecting terminal according to the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. Is. For example, in the above-described embodiment, the case where the rough surface portion is formed on the inner surface of the base portion of the crimping portion and the left and right crimping pieces has been described. The rough surface portion may be formed on either one of the surfaces, and is not particularly limited.

Further, as the crimping portion, a pair of crimping pieces standing upright on the left and right of the base portion has been described, but in addition to this, a plurality of crimping pieces standing upright. Is also good. The left and right crimping pieces may be erected so as not to face each other, and are not particularly limited.

Further, as the electric wire connecting terminal in the above-mentioned embodiment, the case where the tip has the fastening portion as the connecting portion to be connected to the mating side connected portion has been described. It may have a tapered tab part to be inserted into the fitting part of the terminal (in this case, it becomes a male terminal), and has a tubular fitting part into which the tab part of the mating male terminal is inserted. May be used (in this case, it becomes a female terminal). That is, the shape of the connecting portion can be variously changed according to the shape of the mating connected portion, and is not particularly limited.

[0044]

According to the electric wire connecting terminal of the present invention, it is possible to obtain an electric wire connecting terminal which can be electrically connected while destroying the oxide film formed on the surface of the aluminum core portion of the aluminum electric wire.

Therefore, when this wire connecting terminal is used in the automobile field where a large number of wires are used, an operator or the like preliminarily prepares the oxide film on the aluminum core wire portion immediately before connecting the aluminum wire and the wire connecting terminal. Since it is not necessary to perform work such as mechanically breaking and removing with a wire brush,
The work efficiency is greatly improved and the productivity is also improved.

[Brief description of drawings]

FIG. 1 is an external perspective view showing an electric wire connecting terminal provided with a crimping portion in which a rough surface portion is formed.

FIG. 2 is an external perspective view showing a protrusion as a rough surface portion.

FIG. 3 is an external perspective view showing a raised portion as a rough surface portion.

FIG. 4 is a cross-sectional view showing a state of forming a hardened layer as a rough surface portion by shot peening and a hardened layer formed thereby.

FIG. 5 is a cross-sectional view showing a powder layer as a rough surface portion formed by fixing powder.

FIG. 6 is a cross-sectional view showing a state of forming a thermal sprayed layer as a rough surface portion by thermal spraying of metal, and the thermal sprayed layer formed thereby.

FIG. 7 is an external perspective view showing an electric wire connection terminal applied to a conventionally known aluminum electric wire.

FIG. 8 is a diagram showing an upper surface of the wire connection terminal of FIG. 7.

9 is a diagram showing an AA cross section and a BB cross section in FIG. 8;

[Explanation of symbols]

10 Wire connection terminal 12 Aluminum electric wire 13 Aluminum core 14 Crimp part 17 Base 18a Crimping piece 18b crimping piece 19 rough surface 22 Raised part 24 Hardened layer 27 powder layer 29 Sprayed layer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yasuhiro Hattori             1-7-10 Kikuzumi, Minami-ku, Nagoya-shi, Aichi             Auto Network Technical Laboratory Co., Ltd. F term (reference) 5E085 BB02 BB12 CC03 DD14 EE03                       FF01 FF19 GG02 HH21 HH23                       JJ03 JJ49

Claims (6)

[Claims] 1. A wire connecting terminal having a crimping portion for crimping an aluminum core portion of an aluminum electric wire, wherein the crimping portion is erected so as to be opposed to the left and right sides of a base portion for receiving the aluminum core portion. And a rough surface portion capable of scraping off an oxide film formed on the surface of the aluminum core wire portion to be crimped is formed on the inner surface of the base portion and / or the left and right crimping pieces. An electric wire connection terminal characterized in that 2. The wire connecting terminal according to claim 1, wherein the rough surface portion is a cone-shaped protrusion formed on the inner surface of the base portion and / or the left and right crimping pieces. 3. The rough surface portion is a raised portion formed by punching an inner surface of the base portion and / or the left and right crimping pieces from the outer side to the inner side. Wire connection terminal. 4. The rough surface portion is a hardened layer formed by hitting a shot by shot peening on the inner surface of the base portion and / or the left and right pressure-bonded pieces. Wire connection terminal. 5. The rough surface portion is a powder layer formed by fixing powder having hardness equal to or higher than that of the oxide film to the inner surface of the base portion and / or the left and right crimping pieces. The electric wire connection terminal according to claim 1, wherein 6. The wire connecting terminal according to claim 1, wherein the rough surface portion is a sprayed layer formed by spraying a metal on the inner surface of the base portion and / or the left and right crimping pieces. .