JPH10302866A - Connection terminal of fitting type - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connection terminal of fitting type which is given sufficient corrosion resistance as well as reduces the inserting force. SOLUTION: A rust preventive-lubricant of organoamine and paraffin wax dissolved in an organic solvent or water is generated, a male terminal 10 and a female terminal 20 are immersed in the rust preventive-lubricant and dried, or a contacting part of both terminals 10 and 20 is sprayed with the solvent. In the initial state that the rust preventive-lubricant is sprayed on the terminals of a tinning thickness of 0.1 μm, they can maintain contact resistance of the same degree as that of the terminal which is not sprayed. Also, the contact resistance after a corrosion test after spraying the rust preventive-lubricant on the terminals of a timing thickness of 0.1 μm can be reduced to the same degree as the contact resistance after a corrosion test of the terminals of a timing thickness of 0.1 μm. Further, as the wax contained in the rust preventive- lubricant has also lubricity, the effect which reduces the inserting force further can be also obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fitting connection terminal used for electric wiring of automobiles, industrial equipment and the like.

[0002]

2. Description of the Related Art Conventionally, fitting type connection terminals used for connecting electric wires in electric wiring of automobiles, industrial equipments and the like have been generally plated with tin. This is intended to stably obtain a low contact resistance by breaking the surface oxide film of the tin plating by friction at the time of connecting the terminals and adhering fresh tin.

Further, the connection terminals have been plated with gold for the electrical wiring used in particularly important signal circuits such as ABS (anti-lock brake system) and airbag of automobiles.

[0004]

The adhesion of tin plating is caused by the low tin hardness (Vickers hardness: 40 to 80). However, the low hardness of tin causes a problem of increasing the insertion force at the time of connection. That is, when the terminals are fitted and connected, cohesive wear of the tin plating occurs, and the tin is fitted against the deformation resistance of the tin, so that the insertion force increases.

By the way, in the electric wiring of an automobile or the like, a bundle of a plurality of electric wires (hereinafter, referred to as "wire harness") is generally connected by one connector, and a force required for connecting the connector is a terminal. It can be roughly estimated as a value obtained by multiplying the insertion force per unit by the number of electric wires (conventionally, generally 10 to 20 poles). Therefore, when the insertion force per terminal is high, the force required to connect the connector has a large value according to the number of wires of the wire harness.

In particular, the remarkable progress and development of car electronics in recent years has led to a dramatic increase in the number of electronic devices and CPUs mounted on automobiles, which has led to an increase in the number of wires in a wire harness and a multi-pole connector (30 Pole to 40
There is also an increasing demand for the ultimate goal.

However, as described above, when the number of poles of the connector is increased, the force required for connecting the connector also rises in proportion to the number of electric wires, and the connector cannot be connected without an auxiliary mechanism such as a bolt or a lever. Therefore, even if the terminal is downsized, the auxiliary mechanism hinders downsizing and weight saving of the connector.

In order to reduce the insertion force of the terminal, it is conceivable to reduce the contact pressure (pressing force applied to the contact at the fitting portion), but in this case, stable low contact resistance cannot be obtained. In other words, it is difficult to reduce the insertion force of the terminal while maintaining a stable contact resistance, so an auxiliary mechanism is indispensable when making the connector multipolar, which is a factor that hinders the miniaturization and weight saving of the connector. Has become.

If gold plating is used for the connection terminal,
Even if the contact pressure is low, a low contact resistance can be obtained stably, so that the insertion force of the terminal can be reduced, and even if the connector is multi-pole, the force required for the connection does not increase significantly. Since it requires several times to several tens of times the cost as compared with plating, it is not particularly suitable for a multipolar connector.

Therefore, the present inventors have devised a technique for reducing the terminal insertion force by reducing the thickness of tin plating to increase the apparent hardness of the connection terminal. Corrosion resistance (especially sulfur dioxide gas corrosion resistance) when tin plating is thinned
However, according to the result of the test by the present inventors, the corrosion resistance of the connection terminal having the thinned tin plating does not deteriorate to a problem in use. This technique will be described later.

Of course, in electric wiring for automobiles, industrial equipment, etc., it is naturally preferable that the degree of deterioration in corrosion resistance is small, and in many cases it is desired to provide the connection terminals with higher corrosion resistance. In addition, in the case of a connector that is frequently inserted and removed for the sake of maintenance, the tin plating of the terminal may be peeled off and the corrosion resistance may be reduced. Therefore, it is better to improve the corrosion resistance of the connection terminal in advance.

The present invention has been made in view of the above demands, and an object of the present invention is to provide a fitting type connection terminal having a reduced insertion force and sufficient corrosion resistance.

[0013]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a first aspect of the present invention is a fitting-type connection terminal for obtaining electrical contact by fitting a tin-plated male component and female component. An anti-rust lubricant is applied to at least one of the male part and the female part.

According to a second aspect of the present invention, in the fitting connection terminal according to the first aspect of the present invention, the rust preventive lubricant contains a chelating agent and a wax.

According to a third aspect of the present invention, in the fitting type connection terminal according to the first or second aspect of the present invention, the sliding by the fitting of one of the male component and the female component is performed. The moving part is plated with tin having a thickness of 0.1 μm to 0.3 μm, and the sliding part of the other base material is plated with tin having a thickness of 0.1 μm or more.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the present specification, first, the thinning of the tin plating thickness, which is a prerequisite for applying the rust preventive lubrication treatment technique according to the present invention, will be described, and then the application of the rust preventive lubricant will be described.

A. Thinning of tin plating in fitting type connection terminal: A-1. Form of Fitting Type Connection Terminal: FIG. 1 is a side view of the fitting type connecting terminal according to the present invention, and FIG. 2 is a plan view of a connecting portion of the fitting type connecting terminal.

As shown in the figure, the fitting type connection terminal according to the present invention comprises a male terminal 10 and a female terminal 20. The male terminal 10 includes a wire barrel 11 which is a crimping portion with an electric wire,
The tab 12 which is a fitting portion with the female terminal 20 is formed. The upper and lower surfaces of the tab 12 are smooth sliding surfaces.

The female terminal 20 forms a wire barrel 24 which is a crimping part for the electric wire, and a fitting part 25 for the male terminal 10. The fitting portion 25 has a hollow box shape,
1, an emboss 22 and a bead 23 are provided therein. Note that FIG. 2 is a partially cutaway plan view showing the inside of the fitting portion 25.

The emboss 22 is a convex member provided on the upper part of the tongue piece 21, and makes point contact with the sliding surface of the tab 12 when the male terminal 10 is fitted. The tongue piece 21 has a function as a spring for applying a contact pressure, that is, a pressure for pressing the emboss 22 against the tab 12. Also bead 2
Reference numeral 3 also denotes a convex member, which comes into contact with the sliding surface opposite to the surface where the tab 12 and the emboss 22 come into contact, and receives the contact pressure exerted on the tab 12 by the emboss 22.

When fitting the male terminal 10 to the female terminal 20, the tab 12 is inserted into the gap between the emboss 22 and the bead 23. At this time, one of the upper and lower surfaces of the tab 12 slides on the emboss 22 and the other slides on the bead 23.

A-2. Tin plating on fitting-type connection terminals: The base material of the male terminal 10 and the female terminal 20 is copper. If the copper is used as it is, its hardness is high (Vickers hardness of 100 or more) and the contact resistance between the male terminal 10 and the female terminal 20 may be high. Therefore, at least contact portions of both terminals, that is, the tab 12, the emboss 22, and the bead. 23 is tin-plated. By tin plating,
The effect of reducing the contact resistance is as described above.

Conventionally, the thickness of tin plating on a terminal is set to 1.0 μm.
It was above m. This is because the cost of tin plating is relatively low and the corrosion resistance of the terminals is taken into consideration.

The present inventors have devised a thinner tin plating for the purpose of reducing the insertion force. That is, the thickness of the tin plating was reduced to 1.0 μm or less to increase the apparent hardness of the contact portion of the terminal and reduce the insertion force. The effect of reducing the insertion force by reducing the thickness of the tin plating will be described using experimental results shown below.

In the experiment, the thickness of the tin plating of the male terminal 10 and the female terminal 20 was changed from 0.1 μm to 1.0 μm, respectively, and the insertion force when the male terminal 10 was fitted to the female terminal 20 was measured. I went. FIG. 3 shows the experimental results.

The conventional tin plating thickness on the terminal is 1.
When the thickness is 0 μm, the terminal insertion force is 0.74 kgf.
Hereinafter, the description will be continued using this conventional insertion force as a reference value.

As the experimental results show, one of the male terminal 10 and the female terminal 20 has a tin plating thickness of 0.1 μm or more.
If the thickness of 0.3 μm and the thickness of the other tin plating is 0.1 μm or more, the insertion force is at least 10% compared to the standard value.
The above can be reduced (0.67 kgf or less). This is because as the tin plating becomes thinner, the hardness of copper as a base material affects the hardness of the terminal, and the apparent hardness of the terminal increases. The increase in the apparent hardness of the terminal suppressed the adhesion of the tin plating and lowered the insertion force.

However, the tin plating also has a function as a lubricant for the sliding portion, and the male terminal 10 and the female terminal 20.
In both cases, when the thickness of the tin plating is 0.1 μm, the function of the tin plating as a lubricant is lost, and the insertion force is slightly increased due to the friction of the base material.

When thinning the tin plating, nickel plating is applied as a base of the tin plating to prevent the tin plating from alloying with copper.

B. Application of rust preventive lubricant to the mating type connection terminals: The connection terminals are required to have stable low contact resistance and good corrosion resistance in addition to the insertion force. Contact resistance is a characteristic that is naturally required as long as it is a terminal used for connection of electric wiring, and copper, which is a base material of the terminal, is also required to have corrosion resistance since corrosion easily proceeds particularly in a sulfur dioxide gas atmosphere.

FIG. 4 is a diagram showing contact resistance and corrosion resistance when the tin plating thickness of the terminal is thinned and when a rust preventive lubricant is applied to the terminal. This figure shows the contact resistance of the terminal immediately after tin plating and immediately after the application of the rust-preventive lubricant, and the contact resistance of the terminal after further performing a corrosion test.

The solvent used as the rust preventive lubricant is a solvent obtained by mixing an organic amine (here, cyclohexylamine) as a chelating agent and paraffin wax as a wax. In the coating method, first, a solution is prepared by dissolving the organic amine and paraffin wax in an organic solvent or water. Then, the male terminal 10 is placed in the solution.
Then, the female terminal 20 is dipped and dried, or the solution is sprayed on the contact portions of both terminals. The rust preventive lubricant may be applied to only one of the male terminal 10 and the female terminal 20.

As is clear from FIG. 4, although the terminal having a tin plating thickness of 0.1 μm has a slightly higher contact resistance than the terminal having a tin plating thickness of 1.0 μm, it is more sufficiently than the terminal having no plating. Maintains low contact resistance. That is, it can be said that a low contact resistance can be stably obtained if the tin plating is 0.1 μm or more in thickness. Normally, the contact resistance required for the connection terminal is 1.0 mΩ or less, and the terminal having a tin plating thickness of 0.1 μm sufficiently satisfies this requirement. Further, when the above-mentioned rust-preventive lubricant is applied to the terminal having a tin plating thickness of 0.1 μm, the same contact resistance as that of the terminal not applied can be maintained. That is, even if the non-conductive rust preventive lubricant is applied, the contact resistance is not affected.

Next, regarding the contact resistance after the corrosion test, the terminal with a tin plating thickness of 0.1 μm has a tin plating thickness of 1.0 μm.
Although the contact resistance is slightly higher than that of the terminal, the contact resistance is sufficiently lower than the terminal without plating. Further, the contact resistance of the terminal having a tin plating thickness of 0.1 μm after the corrosion test is also 1.
0 mΩ or less, which is below the allowable value of the contact resistance required for the connection terminal.

On the other hand, when the rust preventive lubricant is applied to the terminal having the tin plating thickness of 0.1 μm, the contact resistance after the corrosion test can be reduced to the same level as that of the terminal having the tin plating thickness of 1.0 μm. . This is because the rust preventive lubricant contains an organic amine which is a chelating agent, and the organic amine forms a cyclic compound (chelate compound) by coordination bond with copper (or nickel of the base) of the terminal base material. As a result, the metal on the surface of the base material becomes inactive, resulting in improved corrosion resistance. Further, the wax contained in the rust-preventive lubricant also has water repellency, which contributes to the improvement of corrosion resistance.

Therefore, the tin plating thickness of the terminal is set to 0.1.
Even if the thickness is reduced to μm, the increase in contact resistance due to corrosion is within the allowable limit, but when a rust preventive lubricant is applied to the terminal, more reliable and sufficient corrosion resistance can be imparted.

Further, since the wax contained in the rust preventive lubricant also has lubricity, it has an effect of further reducing the insertion force.

Although the embodiment of the present invention has been described above, the present invention is not limited to the above example.
For example, as the base material of the terminal, besides copper, copper alloy, aluminum, aluminum alloy, iron alloy, stainless steel,
Metallic materials such as nickel alloys can be used.

As the chelating agent contained in the rust preventive lubricant, a benzotriazole-based, benzimidazole-based or imidazole-based cyclic nitrogen compound may be used in addition to the organic amines such as cyclohexylamine and ethylenediamine. .

As the wax contained in the rust preventive lubricant, metal soap or petrolatum may be used in addition to the above paraffin wax.

Further, the present invention is not limited to the case where the tin plating of the terminal is made thin, and can be applied to the terminal used for the connector which is frequently inserted and removed even when the tin plating is thick.

Further, in the above embodiment, the contact portions of the male terminal 10 and the female terminal 20 are thinly plated with tin, but the wire barrel 11, which is the crimping portion with the electric wire,
24 may be provided with a thick tin plating by partial plating. This is because the crimping portion with the electric wire is not required to have characteristics relating to the insertion force, and it suffices that a stable contact resistance can be obtained.

[0043]

As described above, according to the present invention,
Since at least one of the male and female parts is coated with a rust preventive lubricant, it is possible to provide more reliable and sufficient corrosion resistance even when the tin plating is thin, and further reduce the insertion force. You can

[Brief description of the drawings]

FIG. 1 is a side view of a fitting connection terminal according to the present invention.

FIG. 2 is a plan view of a connection portion of the fitting-type connection terminal of FIG. 1;

FIG. 3 is a view showing an experimental result of an insertion force when a tin plating thickness of a terminal is reduced.

FIG. 4 is a diagram showing contact resistance and corrosion resistance when the tin plating thickness of the terminal is thin and when a rust preventive lubricant is applied to the terminal.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Male terminal 12 Tab 20 Female terminal 21 Tongue piece 22 Emboss 23 Bead 25 Fitting part

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junya Shioya 1-7-10 Kikuzumi, Minami-ku, Nagoya-shi, Aichi Prefecture Harness Research Institute Co., Ltd. (72) Inventor Atsuhiko Fujii 1-chome, Kikuzumi, Minami-ku, Aichi 7th-10th Harness Research Institute Co., Ltd.

Claims (3)

[Claims] 1. A fitting-type connecting terminal for obtaining electrical contact by fitting a tin-plated male component and female component, wherein at least one of the male component and the female component is rust-preventive lubricated. A fitting type connection terminal characterized by applying an agent. 2. The fitting type connection terminal according to claim 1, wherein the rust preventive lubricant contains a chelating agent and wax. 3. The fitting type connection terminal according to claim 1, wherein 0.1 μm to 0.1 μm is applied to a sliding portion of the base material of one of the male part and the female part due to the fitting. A fitting-type connecting terminal, characterized in that a tin plating having a thickness of 3 μm is applied, and a sliding portion of the other base material is tin plating having a thickness of 0.1 μm or more.