JP2003272728A - Wire connection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wire connection method capable of lowering contact resistance by breaking an oxide film on the interface between a core part and a terminal. <P>SOLUTION: An external power source 41 is connected to the core part 15a and the terminal 10 through a wire-side electrode 18 and a terminal-side electrode 19, respectively, and a pulse current generation circuit 30 for generating a pulse current is connected between either the electrodes 18 or 19 and the power source 41 to apply the pulse current to either the electrode 18 or 19 sides, so that the oxide film located in the interface between the core part 15a and the terminal 10 to bring the core part 15a into direct contact with the terminal 10. A signal outputted from a control means 45 for transmitting a pulse signal is inputted to a current feed means 31 constituting the generation circuit 30 for generating the pulse current, and the pulse current synchronized with the pulse signal is outputted from the feed means 31. <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 method for connecting an electric wire connected to various electronic devices and a terminal.

[0002]

2. Description of the Related Art A power line for supplying power and a signal line for signals are connected to electronic equipment mounted on a moving body such as an automobile. Copper, copper alloy, or aluminum alloy having excellent conductivity is used for these electric wires. Oxygen-free copper or the like is used in copper alloys to prevent hydrogen embrittlement, and aluminum alloys to which Mg-Si or the like is added are mainly used.

An electric wire made of an aluminum alloy as a constituent material is called an aluminum wire and is distinguished from a copper wire made of copper as a constituent material. Copper wires have the drawback of having a higher specific gravity than aluminum wires, but they have the advantage of high electrical conductivity and are widely used. Aluminum wire has an advantage that it has a low specific gravity but a low specific gravity, and is used in applications such as high voltage electric wires where weight is a problem. As described above, the copper wire and the aluminum wire have different alloy characteristics, but in any case, they are required to have excellent electric conductivity which is a basic characteristic of the electric wire.

A conductive metal terminal is connected to the core portion of the electric wire by crimping or the like. By fitting connectors for accommodating a plurality of terminals, the electric wires can be connected to each other or to the electric wire and the device. The electrical connection is made. There are various methods of connecting the electric wire and the terminal. The so-called overlap crimping method and the B crimping method in which the electric wire and the terminal are positioned and crimped between a set of anvil and crimper.
A mold crimping method is widely known.

The overlap crimping method is a method in which a pair of electric wire crimping pieces are wound around the outer circumference of an electric wire and the tip portions are polymerized to perform crimp connection (Japanese Patent Laid-Open No. 3-165478). On the other hand, the B-type crimping method is a method in which the tip portions of a pair of electric wire crimping pieces are bited into the electric wire and crimped. Here, comparing the two methods, the overlap crimping method has the advantage that crimping connection can be made even if the wire size is different, but the wire crimping piece expands due to the elastic restoring force, so that the wire and terminal are in close contact. However, there is a problem that the contact resistance of the connecting portion is high. On the other hand, the B-type pressure bonding method has an advantage that the contact resistance of the connecting portion is low because the contact pressure is high and the adhesion is strong.

If the contact resistance is high in a power supply line through which a minute current of several mA flows or a signal line for exchanging signals between electronic devices, electricity cannot be energized and the electronic devices and the like operate normally. It may not be possible to make it happen. The problem of contact resistance is not limited to the crimping method, but the B-type crimping method that can lower the contact resistance is used as the crimping method of the electric wire through which a minute current flows and the terminal fitting.

An example of crimping and connecting a terminal to the core of an electric wire by the B-type crimping method is shown in FIGS. As shown in FIG. 4, the terminal 50 is formed by bending a substrate made of a copper alloy, and has an electric contact portion 53 at one end and a wire connecting portion 51 at the other end. ing. Wire connection part 51
Is provided with a pair of crimping pieces 51a and 51b on the front and back. The electric wire 55 includes a core wire portion 55a and a covering portion 55b, and the covering portion 55b is stripped to expose the core wire portion 55a.

The crimping of the electric wire 55 and the terminal 50 is performed by a terminal crimping machine (not shown) or the like. The terminal crimping machine is equipped with a crimper and an anvil. By mounting the terminal 50 on the anvil on the pedestal side, mounting the electric wire 55 on the terminal 50, and inserting the anvil into the guide groove of the crimper on the pressing side, The pair of crimping pieces 51a and 51b are crimped into a B shape, and the electric wire 55 and the terminal 50 are crimped and connected as shown in FIG.

[0009]

However, the above-mentioned conventional wire connecting method has the following problems to be solved.

One problem is that when an oxide film is present on the surface between the core wire portion 55a and the terminal 50, the contact resistance does not decrease even if the contact pressure between the electric wire 55 and the terminal 50 is strong. Japanese Patent Application Laid-Open No. 8-213142 describes that the square of the contact resistance Rc is proportional to the reciprocal of the contact pressure P (Rc ² ∝1 / P) when the terminal is plastically deformed. Not necessarily.

On the contrary, in such a case, if the contact pressure is too high, there is a concern that the pair of crimping pieces 51a may be plastically deformed or damaged. Even if no damage occurs, the terminal 50
The width dimension and height dimension of the connector may exceed the permissible values, making it impossible to make electrical connection with the mating terminal or not being able to be accommodated in the terminal accommodating chamber of the connector housing.

If the contact resistance is high, as described in the section of the prior art, it becomes impossible to pass a minute current, and it becomes impossible to detect a signal. In addition, electric energy is converted into heat energy, which is wasteful. Energy will also be spent. In addition, the amount of electricity consumed by an automobile or the like equipped with an electronic device is increased, which is contrary to low fuel consumption and energy saving. In addition, there is a possibility that circuit damage due to heat generation, equipment damage, or a fire may occur.

In view of the above points, it is an object of the present invention to provide an electric wire connecting method capable of reducing the contact resistance by destroying the oxide film existing on the interface between the core wire portion and the connecting portion.

[0014]

To achieve the above object, the invention according to claim 1 provides an electric wire connecting method for connecting a core wire portion of an electric wire whose insulation coating is stripped and a terminal,
A pulse current generation circuit that connects an external power supply to the core wire portion and the connection portion of the terminal via a wire-side electrode and a terminal-side electrode, and generates a pulse current between any one of the electrodes and the external power supply. Are connected to each other, and the pulse current is applied to one of the electrodes, thereby destroying the oxide film existing on the interface between the core portion and the connecting portion, thereby directly connecting the core portion and the connecting portion. It is characterized by making contact with.

According to the above construction, the terminal is connected to the external power source via the terminal side electrode, the core wire portion is connected to the external power source via the wire side electrode, and one of the electrodes is connected to the external power source from the pulse current generating circuit. By applying a pulsed current, a shock wave of the pulse and an electrochemical reaction cause a crack or other defect in the oxide film existing on the interface between the core and the connection, causing the oxide to peel off and the core and the connection to separate. Direct contact reduces the contact resistance.

According to a second aspect of the present invention, in the electric wire connecting method according to the first aspect, the pulse current generating circuit includes current supply means and control means for switching the current supply means. The pulse signal output from the control means is input to the current supply means, and the pulse current synchronized with the pulse signal is output from the current supply means.

According to the above construction, the control means constituting the pulse current generating circuit continuously outputs the pulse signal having a constant pulse width at a constant interval, and the current supply means switches by inputting this pulse signal. Then, a pulse current synchronized with the pulse signal is output when the switch is on.

The invention according to claim 3 is the wire connecting method according to claim 1 or 2, wherein aluminum is used for the core wire portion, and the pulse current generating circuit is provided between the wire side electrode and the external power source. It is characterized in that the oxide film of the aluminum is destroyed by connecting between the electrodes and applying the pulse current to the electric wire side electrode.

According to the above construction, by connecting the pulse current generating circuit between the wire side electrode and the external power source, the pulse current from the current supply means is applied to the wire side electrode,
The shock wave of the pulse current directly acts on the aluminum oxide film that is dense, has low electronic conductivity, is highly protective, and functions as a barrier layer.

Further, the invention according to claim 4 is the invention according to claim 1
In the electric wire connecting method according to any one of 3 above, the connection portion of the terminal and the core wire portion of the electric wire are positioned between the terminal crimping die on the pressing side and the terminal crimping die on the pedestal side, The terminal portion and the core wire portion are temporarily pressure-bonded by bringing both terminal crimping molds close to each other, and in this temporary pressure-bonded state, the oxide film existing on the interposing surface between the core wire portion and the connection portion is destroyed, and the both terminals are again pressed. The terminal crimping die of (1) is brought into proximity to perform the main crimping of the connecting portion and the core wire portion.

According to the above construction, in the terminal crimping step, the oxide film is destroyed in the temporary crimping state in which the contact pressure between the core portion of the electric wire and the terminal connecting portion is low, so that the destroyed oxide film is peeled off. Then, the connection portion directly contacts the exposed base material of the core wire portion. Then, by performing the main pressure bonding, the contact pressure between the core wire portion and the connection portion is increased, and the electric wire and the terminal are connected without coming off.

The invention according to claim 5 is characterized in that, in the wire connecting method according to claim 4, the terminal crimping mold on the pressing side is the terminal side electrode. According to the above configuration, when the core wire portion and the connection portion are crimped, the oxide film is destroyed at the same time, whereby the terminal crimping step is integrated and streamlined, and the workability is improved.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific examples of embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows an embodiment of a wire connecting method according to the present invention. FIG. 1 shows a terminal 10 crimped to a core portion 15a of an electric wire 15.
And the wire connecting portion (connecting portion) of the core portion 15a and the terminal 10.
13 shows a wire side electrode 18 and a terminal side electrode 19 respectively connected to 13, and a circuit diagram including an external power supply 41 and a pulse current generating circuit 30. The structure of the present invention will be described below in the order of the electric wire 15, the terminal 10, the electrodes 18 and 19, and the circuit diagram, and finally the terminal crimping step will be described.

The electric wire 15 is a core wire portion 15a made of a conductor.
And a covering portion 1 made of an insulating material that covers the periphery of the core wire portion 15a.
5b and. The constituent material of the core wire portion 15a is not particularly limited, but is made of a conductor material excluding plated metal such as tin-plated copper or nickel-plated copper, for example, copper, copper alloy, or aluminum alloy.

The aluminum alloy forming the core portion 15a of the electric wire 15 is an alloy to which elements such as Mg-Si, Mg and Zr are added. Zinc may also be added to lower the contact resistance and improve the electrical conductivity. The added alloy element exists in the matrix as an intermetallic compound or a solid solution. On the other hand, when the core wire portion 15a of the electric wire 15 is made of copper or a copper alloy, oxygen-free copper, tough pitch copper, or the like is used. The so-called plated wire, which is not applicable to the electric wire connecting method according to the present invention, is an electric wire used for applications requiring corrosion resistance and heat resistance.

The covering portion 15b is made of a soft resin such as polyethylene resin, polyvinyl chloride resin, polypropylene resin or the like. Depending on the type of resin material, a material to which a plasticizer is added (polyvinyl chloride resin) or a material subjected to a cross-linking treatment (polyvinyl chloride resin or polyethylene resin) is used. Around the core wire portion 15a, such a covering portion 1
The reason for covering with 5b is to protect the operator from electric shock. When the core wire portion 15a is exposed, the covering portion 15
By making a notch in b and pulling it with a cutter or the like, the covering portion 15b can be easily peeled off.

The terminal 10 is substantially the same as the terminal 50 described in the section of the prior art. The illustrated terminal 10 is integrally formed by punching out a conductive substrate made of copper, a copper alloy, an aluminum alloy, or the like with a press machine and bending the punched board.
Although FIG. 1 shows a part of the male terminal 10,
Not limited to male type, female type terminal (not shown)
May be On one side, a tab-shaped electrical contact 12
(FIG. 3 (c)) is formed, and the electric wire connecting portion 13 is provided on the other side.
Are formed. A hole 12a is provided so as to penetrate the tip end side of the electric contact portion 12. The other terminal (not shown) is also provided with a tab-shaped electric contact portion having a hole portion, and the electric wire connecting portions 13 are overlapped with each other, and a fastening member (not shown) such as a bolt is attached to the hole portion. Both terminals 10 are brought into electrical contact by being inserted.

The wire connecting portion 13 is composed of a core wire crimping piece 13a and a covering crimping piece 13b which are arranged in the longitudinal direction of the terminal 10. The core wire crimping piece 13a and the coated crimping piece 13b are
A pair of core wire crimping pieces 1 is provided on each side of the terminal 10.
3a crimps the core portion 15a of the electric wire 15 to form a coated crimp piece 1
3b crimps the covering portion 15b. The crimping of the electric wire 15 and the terminal 10 is performed by a terminal crimping machine including a crimper (pressing side terminal crimping type) 20 and an anvil (base side terminal crimping type) 25 shown in FIG. , So that the crimp shape is a B-shape.

A copper alloy is preferably used for the electrodes 18 and 19, but the electric conductivity is good, and the core wire portion 15a of the electric wire 15 is used.
Other metals such as platinum and silver may be used as long as the galvano potential is higher than that of the aluminum alloy or copper alloy constituting the. When electrochemically destroying an oxide film (aluminum oxide, copper oxide), if the galvano potential of the electrode material is baser than that of the aluminum alloy or copper alloy, the aluminum alloy or copper alloy cannot serve as the anode site, Oxide film 1
This is because 6 cannot be destroyed. The electrodes made of a tungsten alloy used for welding the copper alloy and the like to the terminal 10 cannot be used as the electrodes 18 and 19 of the present invention because of poor electrical conductivity.

As the external power source 41, a DC power source in which an AC power source is rectified through a rectifier (not shown) is used. This is because in the AC power supply, the magnitude of the current changes in a sine wave shape, and it is not possible to repeatedly transmit a constant pulse, and the oxide film 16 cannot be stably destroyed.
This is the same as the reason why a DC power supply is used for cathodic protection of iron pipes existing in the ground or under the sea by an external power supply method.

Next, the pulse current generating circuit 30 will be described. The pulse current generation circuit 30 includes a current supply unit 31.
And a control means 45 for switching the current supply means 31
And is configured. The current supply unit 31 is an analog circuit that generates a pulse current, and includes a transistor Tr, a resistor R1, and a backflow prevention diode Di. The collector C of the transistor Tr is connected to the external power supply 41 via the switch SW, and the emitter E of the transistor Tr is connected to the resistor R1. The other end of the resistor R1 is connected to the anode an of the diode Di, and the cathode ca of the diode Di is connected to the wire side electrode 18 via the branch point 47 of the conducting wire 46. The base B of the transistor Tr is connected to the output terminal of the control means 45.

The control means 45 is a signal circuit for generating a pulse signal for switching the current supply means 31. To generate the pulse signal, a thyristor, a blocking oscillator (not shown), or a sawtooth oscillator having a flip-flop circuit (not shown) can be used. A minute current is input to the control means 45 via an internal resistor and pulse signals having a predetermined pulse width are output at regular intervals. Further, the control means has a bias circuit for stably operating the transistor Tr.

Next, the operation of the pulse current generating circuit 30 will be described. When the switch SW is turned on, the external power supply 41
Is converted into a minute current by the resistor R2 and supplied to the wire side electrode 18. Since this minute current is several mA, the oxide film 16 existing on the interface between the core portion 15a of the electric wire 15 and the terminal 10 is not broken.

Even if a minute current of about several mA is applied, oxidation
The reason why the destruction of the film 16 does not occur will be described below. Electric wire 1
If 5 is an aluminum wire, the film thickness and temperature
The breakdown voltage of the oxide film 16 varies depending on
This is because it is as high as several V to 10 V. This is the breakdown voltage
Amorphous oxide film formed on the surface shows such a value.
Ultra-thin film thickness of 16 is about 1 nm (10 Å) at room temperature
Despite the fact that it adheres well to the substrate,
This is because it is a wall layer. Note that due to the presence of water,
When a crystalline film is formed on the oxide film 16 of the shape
(Orthorhombic trihydrate oxide (Al ₂O₃・ 3H₂O) etc. are thick and raw
However, it may vary depending on the thickness of the film.
However, it is necessary to apply a voltage exceeding 10V.

When the electric wire 15 is a copper wire, the characteristics of its oxide film (CuO, Cu ₂ O, etc.) are different from those of an aluminum alloy. The oxide film is not stoichiometric copper oxide, the film itself is not dense, and the film thickness is 10 nm (100
Å) Grow more than that. The film contains a large amount of oxygen to form a porous layer. Therefore, the insulating property is not so high as that of the aluminum alloy, and the oxide film is relatively easily broken.

Returning to FIG. 1, the description will be continued. Control means 45
The pulse signal input from the transistor Tr to the base B of the transistor Tr has, for example, a pulse width of 125 μsec and a period of 1 mse.
It is a signal of c. The current supply means 31 is switched in synchronization with the pulse signal. Base B
The current flowing from the emitter to the emitter E is a minute current of several mA, but due to the amplifying action of the transistor Tr, a current of several hundred mA flows from the collector C to the emitter E, and the core wire portion via the wire side electrode 18. A pulse current is applied to 15a.

Then, the pulse current passes through the core portion 15a of the electric wire 15, the electric wire connecting portion 13 of the terminal 10 and the terminal side electrode 19 in this order and returns to the external power supply 41. That is, the external power supply 41, the core wire portion 15a, and the terminal 10 form a closed circuit, and pulse current flows intermittently unless the switch SW is turned off.

As a result, the oxide film 1 on the core portion 15a is formed.
No. 6 is destroyed by both the impact action and the electrochemical action by the pulse current, the base of the core wire portion 15a is exposed, the core wire portion 15a and the terminal 10 are directly contacted, and the contact resistance is reduced.

FIG. 2 shows a state in which the core wire portion 15a made of an aluminum alloy and the terminal 10 are pressure-bonded to each other. As shown in FIG. 2 (a), before the oxide film 16 is destroyed, the oxide film 16 is formed on the outer periphery of the core wire portion 15 a, so that the oxide film 16 is formed on the contact portion 49 between the core wire portion 15 a and the terminal 10. There are sixteen. Since the oxide film 16 of the aluminum alloy has a high insulating property, the core wire portion 15a and the terminal 10
The contact resistance with and becomes high, and sometimes exceeds several hundred mΩ. If the contact resistance becomes high, it becomes impossible to detect a signal of a minute current, and it becomes impossible to supply a current to the device or the like, and the device cannot operate normally. In addition, heat generation causes energy loss.

FIG. 2 (b) is a view showing a pressure-bonded state after the oxide film 16 is destroyed. Since the oxide film 16 is destroyed and peeled off, the contact portion 4 between the core wire portion 15a and the terminal 10 is shown.
9 does not have an oxide film 16, and the terminal 10 is in direct contact with the base material of the core portion 15a. The contact resistance in the state where the oxide film 16 does not exist is at most about several mΩ.

FIG. 3 is an explanatory view showing a crimping process of the electric wire and the terminal. First, as shown in FIG. 3A, a cross-sectional view U is formed on the anvil 25 arranged so as to face the crimper 20.
A terminal 10 having a V-shaped core wire crimping piece 13a is placed. The mounting surface 25a of the anvil 25 is formed in a concave shape so as to circumscribe the curved bottom wall 11 of the terminal 10.
An electric wire 15 is placed on the terminal 10.

The crimper 20 will now be described. The crimper 20 has a rectangular plate shape, and a guide portion 21 that allows the anvil 25 to enter is provided at a lower end portion on the side facing the anvil 25. In the guide portion 21,
An inner side surface 22 having a tapered shape and a caulking portion 23 a located at the back side of the inner side surface 22 are formed. Caulking portion 23a
Are formed symmetrically with respect to the central axis, and a protrusion 23b is formed at the center where the caulking portion 23a meets.

FIG. 3B shows a state in which the core wire portion 15a and the core wire crimping pieces 13a, 13a are temporarily crimped.
The wire connecting portion 13 is crimped into a B shape, but the core wire portion 15a and the wire connecting portion 13 are not strongly crimped.

FIG. 3 (c) is a view similar to that of FIG.
In the state of FIG. 3B, a process of destroying the oxide film 16 existing on the intervening surface of the core portion 15a and the terminal 10 is shown. The wire-side electrode 18 is connected to the positive electrode of the external power supply 41, and the terminal-side electrode 19 is connected to the negative electrode of the external power supply 41. When the switch SW is turned on, the pulse current generation circuit 30
Pulse current is intermittently applied to the wire-side electrode 18. In addition, the terminal side electrode 19 is connected to the electric wire connecting portion 13 of the terminal 10.
Alternatively, the crimper 20 may be used as the terminal-side electrode 19 instead of connecting. Since the crimper 20 also serves as the terminal-side electrode 19, the oxide film 16 can be destroyed at the same time when the core wire portion 15a and the electric wire connecting portion 13 are crimped, and the terminal crimping process can be integrated and streamlined.

Thus, the core portion 15a and the electric wire connecting portion 1
By destroying the oxide film 16 in the temporary crimping state of No. 3, the destroyed oxide film 16 is removed, and then the main wire crimping is performed to directly contact the wire connecting portion 13 with the exposed base wire portion 15a. To do. The pulse current generating circuit 30 has already been described with reference to FIG. 1, and thus its description is omitted here.

When the electric wire 15 is an aluminum wire and the terminal 10 is a copper alloy, the pulse current generating circuit 30 is connected in parallel between the external power source 41 and the electric wire side electrode 18 as shown in the figure. A pulse current is directly applied to the core wire portion 15a via the wire side electrode 18, and the oxide film 16 of the wire 15 is effectively destroyed. Terminal 1 made of copper alloy
When destroying the oxide film generated at 0, the pulse current generating circuit 30 is connected in parallel between the external power supply 41 and the terminal electrode 19 to effectively destroy the oxide film.

FIG. 3 (d) shows a state in which the core wire portion 15a and the core wire crimping pieces 13a, 13a are fully crimped. The core wire crimping pieces 13a on both sides are deeply inwardly crimped in accordance with the crimping portion 23a of the crimper 20, and the tip ends thereof are embedded in the core wire portion 15a. The core wire portion 15a and the terminal 10 are in contact with each other with a predetermined contact pressure, and the core wire portion 15a is in contact with the terminal 10.
You can't get out of it. In this way, the core wire portion 1
5a and the terminal 10 have an oxide film 16 on both surfaces.
Is destroyed and crimp connection is made with a small contact resistance.

The pulse current generating circuit 30 of FIG. 1 is provided with the backflow prevention diode Di, but when the transistor Tr is excellent in reverse breakdown voltage,
This diode Di is not always necessary.

Although the resistor R1 is provided, if the rectified external power source 41 can apply an arbitrary voltage, the resistor R1 is not necessary. For example,
By using a direct current stabilized power supply (not shown) configured by including a transformer that transforms alternating current, a diode bridge that rectifies alternating current, and a capacitor that smoothes pulsating current,
The resistor R1 can be eliminated.

Further, in FIG. 3, even after the core wire portion 15a and the terminal 10 are completely pressure-bonded to each other, by applying a pulse current, the oxide film 16 can be destroyed and the contact resistance can be reduced.

[0051]

As described above, according to the invention of claim 1, by applying the pulse current from the pulse current generating circuit to either one of the terminal side electrode and the wire side electrode,
Due to the impact action and electrochemical action of the pulse, the oxide film existing on the intervening surface between the core wire portion and the connection portion is destroyed, and the core wire portion and the connection portion are directly connected. Therefore, the contact resistance can be reduced without increasing the contact pressure between the core wire portion and the connection portion.

According to the second aspect of the invention, the current supply means is switched by inputting the pulse signal from the control means, and the pulse current synchronized with the pulse signal in the switch-on state is the current supply means. Is output from. Therefore, the oxide film existing on the intervening surface between the core portion and the connecting portion can be destroyed, and the contact resistance between the core portion and the connecting portion can be reduced similarly to the effect of the first aspect of the invention.

According to the third aspect of the invention, the pulse current is applied to the wire side electrode, and the pulse current directly acts on the aluminum oxide film forming the core portion. Therefore, even if a dense and highly protective oxide film is present on the surface between the aluminum and the terminal, the oxide film can be destroyed and the contact resistance can be reduced.

Further, according to the invention described in claim 4, the oxide film is destroyed in the temporary crimping state of the core wire portion and the connecting portion to remove the broken oxide film, and then the main compression bonding is performed. , The connecting part directly contacts the exposed base material of the core part. Therefore, the effect of claim 1 is promoted, and the contact resistance can be further reduced.

According to the fifth aspect of the invention, the oxide film can be destroyed at the same time when the core wire portion and the connecting portion are pressure-bonded. Therefore, the terminal crimping process can be integrated and streamlined, and the workability can be improved.

[Brief description of drawings]

FIG. 1 is a front view showing a wire connection method according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a state in which a core wire portion and an electric wire connecting portion are pressure-bonded to each other, FIG. 2 (a) is a cross-sectional view showing a pressure-bonded state before the oxide film is destroyed, and FIG. It is sectional drawing which shows the following crimping | bonding state.

FIG. 3 is an explanatory view showing a crimping process of the electric wire and the terminal, showing (a) a state in which the terminal is placed on the anvil;
(B) is a diagram showing a state in which a core wire portion and an electric wire connecting portion are temporarily crimped, (c) is a diagram showing a step of destroying an oxide film existing on an intervening surface of the core wire portion and the electric wire connecting portion, and (d) is a core wire portion It is a figure which shows the state which carried out the main pressure bonding of the electric wire connection part.

FIG. 4 is a diagram showing an example of a conventional electric wire connection method,
(A) is a plan view and (b) is a front view.

5 is a cross-sectional view showing a state in which an electric wire is crimped to the terminal shown in FIG.

[Explanation of symbols]

10 terminals 13 Wire connection part (connection part) 15 electric wires 15a core part 16 oxide film 18 Wire side electrode 19 Terminal side electrode 30 pulse current generation circuit 31 Current supply means Tr transistor Di diode 41 External power supply 45 Control means

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor ▲ Kuwa ▼ Yasuji Yama             206-1 Nunobikihara, Haibara-cho, Haibara-gun, Shizuoka Prefecture Yazaki             Parts Co., Ltd. (72) Inventor Masanori Onuma             206-1 Nunobikihara, Haibara-cho, Haibara-gun, Shizuoka Prefecture Yazaki             Parts Co., Ltd. (72) Inventor Koichi Shiramizu             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. F term (reference) 5E085 BB03 BB12 CC09 DD13 FF01                       HH06 HH13 HH35 JJ03

Claims (5)

[Claims] 1. A wire connection method for connecting a core wire portion of an electric wire whose insulation coating is stripped and a terminal, wherein the core wire portion and the connection portion of the terminal are connected to each other via a wire side electrode and a terminal side electrode. By connecting a power source, connecting a pulse current generating circuit for generating a pulse current between any one of the electrodes and the external power source, and applying the pulse current to the one of the electrodes, the core wire portion An electric wire connecting method, characterized in that an oxide film existing on the interface between the wire and the connecting portion is destroyed to directly contact the core wire portion and the connecting portion. 2. The pulse current generating circuit comprises a current supply means and a control means for switching the current supply means, and inputs a pulse signal output from the control means to the current supply means, 2. The electric wire connecting method according to claim 1, wherein the pulse current synchronized with the pulse signal is output from the current supply means. 3. The aluminum is used for the core wire portion, the pulse current generating circuit is connected between the wire side electrode and the external power supply, and the pulse current is applied to the wire side electrode, The electric wire connecting method according to claim 1 or 2, wherein the oxide film of aluminum is destroyed. 4. A terminal crimping die on the pressing side and a terminal crimping die on the pedestal side are positioned between the connecting portion of the terminal and the core wire portion of the electric wire so that both terminal crimping dies are brought close to each other. By temporarily crimping the connection portion and the core wire portion with each other, by destroying the oxide film existing on the interposing surface between the core wire portion and the connection portion in this temporary crimping state, the terminal crimping molds of both the terminals are brought close again. The electric wire connecting method according to claim 1, wherein the connecting portion and the core wire portion are permanently pressure-bonded to each other. 5. The wire connecting method according to claim 4, wherein the terminal crimping die on the pressing side is the terminal side electrode.