JPS6030043B2 - Automotive wire conductor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wire conductor for automobiles, and is aimed at reducing the weight of electric wires.

In recent years, as the performance of automobiles has improved, the number of wiring locations within automobiles has increased, including an increase in the number of various control circuits, and the reliability required for these has also become more demanding.

On the other hand, from the standpoint of energy conservation, there has been a strong demand for reducing the weight of automobiles. In view of these circumstances, the present invention aims to provide an electric wire conductor for automobiles that is reliable and can be lightweight.

Traditionally, electric wire conductors for automobile wiring mainly use JISC.
Annealed copper wire as specified in 3102 or a stranded wire made by twisting wires that have been tinned etc. is used,
This was coated with an insulator such as vinyl chloride, cross-linked vinyl, or cross-linked polyethylene in the same D-circular shape to form an electric wire.

Incidentally, as mentioned above, in recent years, the proportion of automotive wiring circuits, especially signal current circuits for control purposes, has been increasing.

Although such electric wires have sufficient current carrying capacity, a conductor with a diameter larger than the electrically required diameter is used to maintain mechanical strength. In an attempt to reduce the weight of such electric wires, some studies have also considered using aluminum (including alloys, the same hereinafter) for the conductor. However, aluminum is generally weak in strength, and in order to obtain sufficient strength it is necessary to make the outer shell thicker or increase the number of stranded wires, which requires a large amount of insulator, which takes up wiring space. In addition to requiring a large amount of heat, the effect of reducing weight could not be expected to be sufficient, and the cost of insulators tended to increase. Furthermore, many terminals are used in automobile wiring, but these terminals have various drawbacks, such as electrical corrosion at the terminals and difficulty in joining by soldering.
The present invention was made after various studies with the aim of reducing the weight of electric wires for automobile wiring, particularly electric wires that do not require a large current capacity, such as those used in control circuits. The present invention is made by twisting elementary conductors made of copper or copper alloy with a 0.2% yield strength (hereinafter simply referred to as yield strength) of 30 to 40k9' and a conductivity of 50% IACS or more. Features a cross-sectional area of 0.
It is an electric wire conductor for automobiles with a thickness of 15 to 0.5. FIG. 1 is a cross-sectional view showing an embodiment of the present invention, in which a wire conductor 1 is made by stranding seven elementary conductors 2 made of the above-mentioned copper or steel alloy. The number of twists in the conductor of the present invention has a total cross-sectional area of 0.15 to
If it is 0.5 Yu, the number will depend on the total cross-sectional area. In order to maintain the flexibility of the wire conductor, it is preferable to have a large number of twists, even if the cross-sectional area is the same. Since it has to be set in the line equipment and it is difficult,
37 pieces, more preferably 7 to 19 pieces are recommended. In the present invention, the proof stress is defined as 30 to 40 kg/m2 because if it is less than 30 k9/m, the holding force of the terminal after the electric wire is crimped to the terminal housing or fixed by soldering after crimping (the electric wire's axial direction is limited). This is because it is difficult to obtain a sufficient load (when the wire breaks due to tension or when the wire is pulled out from the crimped part), and if the proof stress exceeds 40k9/fence, the wire will not break due to tension at the crimped part. Although it is difficult to do so, it is easy for the wire to come out of the terminal, and the holding power of the terminal is reduced compared to stranded wire that has a proof strength within the specified range, and it does not lose its flexibility, making it easier to work with wiring etc. This is because the joint portion with the terminal is likely to break due to repeated bending.

When the conductivity is less than 50% IACS, when the cross-sectional area of the stranded wire is 0.15 to 0.5 squares as in the present invention, when the reduction in the cross-sectional area is taken into account, it is extremely difficult to conduct the conductivity compared to the conventional thicker annealed copper wire. This is because the resistance value of the conductor increases, and because copper alloys with electrical conductivity of less than 50% IACS are generally inferior in workability and solderability compared to copper alloys with electrical conductivity of 50% IACS or more.

With conventional annealed copper wire, it is difficult to obtain sufficient mechanical properties such as terminal holding power when the cross-sectional area is less than 0.5 squares, and conductors with such a cross-sectional area have not been used as automobile electric wires. The present invention aims to reduce the weight by making this 0.15 to 0.5 gauge without reducing the terminal holding force. The cross-sectional area of the twisted wire is 0.15 to 0.5
Fences are defined as those with a proof strength of 30 to 30 cm if the area is less than 0.15 square meters.
Even if it is 40k9/grandson, the yield strength of conventional tough pitch annealed copper wire is generally 8 to 12k9/boiled, so 7'0.320 (
JISO. This is because the value is smaller than the yield strength x cross-sectional area of the Hiro V electric wire conductor), which makes it susceptible to deformation due to tension.If it exceeds 0.5, even conventional tough pitch mild steel is almost satisfactory in terms of strength. However, it was surprising that the purpose of weight reduction was achieved.

In the present invention, ■Sn is used as a copper alloy in order to further improve reliability against repeated bending and to easily obtain an elementary conductor for a fence with a yield strength of 30 to 40k9/fence. Base cloud amount%
(hereinafter simply referred to as %): Copper alloys containing the following, with the remainder essentially consisting of copper, and ■Cro. Contains 3-0.9%,
It is even more desirable to use a copper alloy with the remainder consisting essentially of copper. In the above, if Sn exceeds 0.9%, no further improvement in mechanical properties can be expected for the application, and the conductivity will decrease unnecessarily, resulting in a 50% IACS
This is because it tends to be less than In addition, Cr is added from 0.3 to 0.
The reason for specifying 9% is that if the Cr content is less than 0.3%, the effect of improving mechanical properties will not be sufficient, so it is not economical considering the decrease in casting workability and the labor of heat treatment due to the addition of Cr. This is because adding more than .9% only increases raw material costs and tends to impair processability, but no further improvement in properties is observed.

In the present invention, especially when further improvement in solderability is required, the conductor may be plated with tin or the like.

Hereinafter, the present invention will be explained in more detail with reference to Examples. The Cu-Sn alloy of the example was made into an 8-side ◇ wire rod by adding and adding Sn alone to port water in which ordinary electrical copper ingots were melted, and after rolling, casting and hot rolling.

Similarly, in the Cu-Cr alloy, after deoxidizing Cr with P, Cu-10%C
After the Cr was added in the form of an R master alloy and sufficiently melted, it was cast and hot rolled to form an 8-side J wire rod, and then subjected to solution treatment at 950° x lhr and water quenching. These wire rods are made of ordinary tough pitch steel and oxygen-free steel.
The wire was drawn together with the side wire rod to form a wire on the 0.26 side ◇ or 0.32 side. Regarding EC aluminum, from 12 side 0 wire rod to 0.32 side? The wire was drawn.
Regarding these hardwoods, in the case of the present invention example shown in Table 1, tough pitch steel has 170 × lhr, and oxygen-free steel has 1hr.
85 0xlhr, Cu-0.62%Sn alloy is 300
Perform batch-type anchoring in an oo×lhr inert atmosphere furnace,
Further, the Cu-0.45% Cr alloy was passed through a nitrogen gas tunnel furnace at 650° C. at a rate of 30 min/min, and was continuously annealed to produce elementary conductors. In addition, for the elementary conductors of comparative examples, the respective materials were made of hard materials or were sufficiently softened. The elementary conductors thus obtained were processed into twisted wires having the configurations shown in Table 1 to form conductor parts. Some of the characteristics were measured with such a bare conductor, but others were measured with 0.
The wire was coated with PVC to a thickness of 5 sides and measured as an electric wire for an automobile.

The results of measuring various characteristics of these electric wires are shown in Table 1.

Here, we will add an explanation of the relationship between the measurement items, their measurement methods, and the characteristics required for automotive electric wires.

As mentioned above, the terminal housing retention force is an important characteristic for automotive electric wires for the reliability of the connection to the terminal.
The measurement was performed by crimping the conductor to a terminal, then pulling the conductor in the axial direction using a tensile tester, and measuring the load when the wire was pulled out (or broken) from the crimped part. This holding force is often 1
It is desired that the value is 0k9 or more. Further, the tensile breaking load is approximately 10k9 or more within a range that does not affect the flexibility of the conductor, and the larger the better.

In addition, the bending resistance of the electric wire is desired to be such that the conductor does not break when repeatedly bent, especially near the terminal portion. With a load W of 500 mm applied to one end, the tube was bent alternately from side to side at 90 degrees, and the number of times it took to break was calculated as 9 round trips.

Solderability was determined by immersing the specimen in white rosin flux and then immersing it in 230 oo of eutectic solder for 2 seconds, then examining the ratio of the area wetted by molten solder to the total immersion surface area. Those with a rating of less than 90% were classified as good, and those with less than 90% were considered poor.

Table 1 shows that the conductor of the present invention has better terminal housing holding power, tensile breaking load, flexibility, and solderability than the conventional conductor made of mild steel with a large cross-sectional area, which is desirable for automotive electric wires. This shows that there is no inferiority in terms of weight, and that it is possible to significantly reduce the weight.

Furthermore, compared to aluminum conductors, it has much higher mechanical properties and higher reliability, and is also superior in reducing wiring space. In addition, especially Cu-0.62%
It can be seen that wire conductors made of alloys such as Sn alloys and Cu-0.45%Cr alloys are easily manufactured and have excellent properties.

As mentioned above, the present invention has a 0.2% yield strength of 30 to 40.
k9/ boiled, the conductor for automobiles has a cross-sectional area of 0.15 to 0.5, characterized by being made by twisting elementary conductors made of copper or copper alloy with an electrical conductivity of 50% IACS or higher, Even if the cross-sectional area is smaller than that of the conventional type, the mechanical properties such as holding force, tensile breaking load, and repeated bending after fixing to the terminal housing are comparable to conventional ones, and the solderability is good, and the wiring etc. The wire has good workability, fully satisfies the characteristics required as an electric wire for automobiles, improves reliability, and makes it possible to reduce the weight of the electric wire and the wiring space.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention. FIG. 2 is a diagram illustrating an aspect of the bending test. 1...
...Wire conductor, 2...Elementary conductor, 3...
・Coated electric wire, 4...Odor control, W...Load. Oh diagram 2 diagram

Claims (1)

[Claims] 1. An element conductor made of copper or copper alloy having a 0.2% yield strength of 30 to 40 kg/mm^2 and a conductivity of 50% IACS or more is twisted together to have a cross-sectional area of 0.15 to 40 kg/mm^2. 0.5mm^2
An electric wire conductor for an automobile characterized by the following. 2. The electric wire conductor for an automobile according to claim 1, wherein the copper alloy contains 0.9% by weight or less of Sn, and the remainder essentially consists of copper. 3. The electric wire conductor for an automobile according to claim 1, wherein the copper alloy contains 0.3 to 0.9% by weight of Cr, and the remainder essentially consists of copper.