JP4728603B2 - Aluminum conductive wire for automobile wiring and electric wire for automobile wiring - Google Patents

Description

  The present invention relates to an aluminum conductive wire, and is lightweight, excellent in flexibility and flexibility, excellent in application to a moving part such as a drive unit, and particularly suitable for wiring of an automobile, and used for a wire harness and a battery cable. It relates to an aluminum conductive wire.

  Conventionally, an annealed copper wire as stipulated in JIS C3102 as a wiring wire for automobiles, and a wire obtained by tinning the annealed copper wire are twisted to form a stranded wire conductor. Wires coated with an insulator such as have been used.

  In recent years, as the performance and functionality of automobiles has increased, the control circuits for various electronic devices have increased, increasing the number of wiring locations in the automobile and increasing the weight due to the wiring. It is becoming. In addition, the demand for reduction in wiring space and weight reduction can be met by making the wires thinner, and further, the environmental protection feeling has increased, and therefore automobile wires that are easy to recycle are required.

  In response to these requirements, automotive wire conductors that use steel wires coated with copper to obtain the required electrical conductivity, improve solder adhesion, and have improved flexibility and tensile strength are known. (For example, refer to Patent Document 1).

Furthermore, without using a copper alloy wire, a hard copper wire and an annealed copper wire are twisted together to ensure mechanical strength by reducing the diameter, and the cross-sectional area of the conductor is 0.3 mm which is lighter and more recyclable. ² or less automotive wire conductors are also known (see, for example, Patent Document 2).

  In Patent Document 3, a wiring conductor having a zinc alloy coating on an aluminum wire is used to solve the problem of electrical connection, and since no copper wire conductor is used, there is no copper contamination when recycling an automobile. There is known a wire conductor for wiring in which deterioration of the quality of recycled steel materials is suppressed.

  Furthermore, Patent Document 4 discloses an aluminum wire for an automobile wire harness in which an aluminum alloy thin wire containing Fe, Si, and Mg is a stranded wire.

Japanese Patent Laid-Open No. 3-184210 JP-A-6-060739 Japanese Patent Laid-Open No. 6-203639 JP 2004-134212 A

  However, the electric wire conductor for automobiles disclosed in Patent Documents 1 and 2 is heavy for a conductor made of copper or copper alloy, and is connected to a terminal or the like using solder. Lead contained in solder is one of the environmental pollutants and has become a big problem.

  Next, the electric wire conductor for wiring disclosed in Patent Document 3 uses an aluminum wire coated with a zinc alloy as a conductor, and is extremely effective as part of ease of recycling and weight reduction. However, the aluminum wires used for thin wires are mainly hard aluminum wires for electrical use (JIS C3108), etc., which are significantly less flexible than copper wire conductors and are repeatedly opened and closed around the door hinges of automobiles. When it is applied to a part having a large number of times, it breaks early and there is a problem that it cannot be used for such a structural part.

  Patent Document 4 discloses an aluminum electric wire for an automobile wire harness having a composition similar to that of the present invention, but Fe content is 0.6% or less than the present invention, and Si content is 0.2-1. It is contained as much as 0% and is greatly different from the present invention. Therefore, the electrical conductivity exceeding 58% IACS cannot be obtained, and the flexibility is harder than the copper electric wire, and further improvement has been desired.

  In order to reduce the weight as much as possible from the viewpoint of improving the performance of automobiles, the present invention has conducted various test studies on aluminum wiring of automobile wire harness conductors, and has characteristics as conductors such as conductivity and bending resistance. It is an object of the present invention to provide an aluminum conductive wire that can sufficiently replace the conductive wire using a conventional copper wire conductor that can sufficiently reduce the weight.

The invention according to claim 1 is an aluminum comprising Fe of 1.10 to 1.50 mass%, Mg of 0.05 to 0.25 mass%, Si of 0.02 to 0.06 mass%, and the balance being Al and inevitable impurities. alloy was pressurized Engineering in roughing line by continuous casting and rolling method, the roughing line were cold drawn to have a diameter of 2.6mm, the heat treatment the tensile strength in the diameter 2.6mm becomes less 150MPa An aluminum alloy wire having a wire diameter of 0.07 to 1.50 mm obtained by applying a heat treatment at a temperature of 350 ° C. for 2 hours and subsequently cold working is used as a strand, and the strand has a radius of 90 mm. The aluminum conductive wire for automobile wiring is characterized in that the number of times of bending until breaking in 30 degree reciprocal bending at 100 times / minute is 110,000 times or more, and the strands are twisted together .

The invention according to claim 2 is the aluminum conductive wire according to claim 1, wherein the strand has a tensile strength of 240 MPa or more.

The invention according to claim 3 is an automotive wiring electric wire obtained by further coating the aluminum conductive wire for automotive wiring according to claim 1 , wherein the tensile strength is 140 MPa or more. Wire.

  According to the aluminum conductive wire of the present invention, weight reduction is achieved by making the aluminum wire, workability at the time of wire drawing, conductivity, twistability (whether or not stranded wire processing is possible), and bending resistance (when opening and closing an automobile door) ), Flexibility (when wire harness is assembled), excellent connection with similar and dissimilar metals, and heat resistance. Also, recycling is much easier than copper wire harness conductors, and no harmful substances for the environment are generated. It has a useful effect such as being clean.

  FIGS. 1A, 1B and 1C are cross-sectional views of an aluminum conductive wire showing an example of an embodiment of the aluminum conductive wire according to the present invention. In FIGS. 1A, 1B and 1C, 1 is an aluminum conductive wire, 2 is a stranded wire, 2a is a compressed conductor stranded wire, 3 is an aluminum alloy strand, and 4 is a coating resin. Here, the number of the aluminum alloy strands 3 constituting the stranded wires 2 and 2a is determined by the performance of the equipment used.

  Next, in the component composition of the aluminum alloy wire constituting the aluminum conductive wire, first, the reason for limiting the Fe content to 1.10 mass% or more and 1.50 mass% or less (hereinafter, mass% is abbreviated as%) When the content is less than 1.10%, the tensile strength is low, and it is difficult to use it in a portion that requires flexibility. Further, if the content exceeds 1.50%, the electrical conductivity required for automobiles with 58% IACS or more cannot be obtained. Therefore, the Fe range is set to 1.10% or more and 1.50% or less. Preferably it is 1.20% or more and 1.40% or less.

  The reason for limiting the amount of Mg to be 0.03% or more and 0.25% or less is that if 0.25% is exceeded, desired conductivity cannot be obtained, and if it is less than 0.03%, flexibility is seen to be improved. It is because it is not possible. Therefore, the range of Mg is limited to 0.03% or more and 0.25% or less, preferably 0.05% or more and 0.15% or less.

The reason for limiting the Si content to 0.02% or more and 0.06% or less is that if it exceeds 0.06%, the desired conductivity cannot be obtained, and conversely if it contains less than 0.02% This is because no improvement in flexibility is observed. Therefore, the range of Si is limited to 0.02% or more and 0.06% or less, preferably 0.035% or more and 0.045% or less.
It should be noted that the content of excessive inevitable impurities is preferably small in order to reduce the conductivity, and Mn is 0.02% or less, and the total amount of Ti and V is preferably 0.025% or less.

Next, the aluminum conductive wire having a wire diameter of 0.07 to 1.50 mm twisted, and the tensile strength of the aluminum conductive wire coated with resin thereon is limited to 140 MPa or more. In order to prevent the connection portion between the aluminum conductive wire and the terminal from being broken during the work of assembling the motor to the automobile, it is necessary to have a tensile strength of a predetermined level or more. Kept. For this reason, the aluminum alloy wire to be used also needs a tensile strength of at least 140 MPa, preferably 160 MPa or more. It is known that the coating resin layer hardly contributes to the tensile strength of the aluminum conductive wire.
The conductivity is required to be high conductivity as the in-vehicle electronic device of the automobile is advanced, and the conductivity is preferably 58% IACS or more.

In practice, when higher flexibility is required while maintaining sufficient flexibility, these effects can be obtained by applying heat treatment after wire drawing or stranded wire processing.
Furthermore, by performing low-temperature annealing after wire drawing, it becomes possible to enhance flexibility while maintaining tensile strength. As the conditions, heat treatment is preferably performed at a temperature of 80 ° C. to 120 ° C. for a time of 100 to 120 hours.

  The coating resin used in the present invention is preferably polyvinyl chloride (PVC) or a non-halogen resin from the viewpoints of insulation and flame retardancy. In particular, although there is no restriction | limiting in the thickness, it is not preferable that it is too thick industrially. Although depending on the wire diameter of the stranded wire, the thickness is preferably about 0.10 mm to 1.70 mm.

Hereinafter, the present invention will be described in detail with reference to examples.
(Example 1)
Table 1 shows the component composition of the Al alloy according to the present invention. An Al alloy having the component composition shown in Table 1 was melted by a conventional method and processed into a rough drawn wire having a wire diameter of 9.5 mm by a continuous casting and rolling method. In addition, the processing method to this rough drawing line is not limited to the continuous casting rolling method, You may use other processing methods, such as an extrusion method.
Next, after drawing this rough drawn wire to a wire diameter of 2.6 mm, a heat treatment was held at 350 ° C. for 2 hours so that the tensile strength after heat treatment was 150 MPa or less, and the wire drawing was continued. An aluminum alloy strand having a wire diameter of 0.32 mm was produced.
Since the tensile strength, flexibility, and conductivity of the aluminum conductive wire according to the present invention in which a stranded wire is coated with a resin are affected by the properties of the aluminum alloy wire used, an aluminum alloy having a produced wire diameter of 0.32 mm The tensile strength, flexibility, and conductivity were evaluated using the strands.

  The tensile strength was determined by measuring the tensile strength of an aluminum alloy wire having a wire diameter of 0.32 mm at n = 3 according to JIS Z2241, and calculating the average value.

  For electrical conductivity, as well as tensile strength, the resistivity of the aluminum alloy wire with a wire diameter of 0.32 mm was measured using a four-terminal method in a constant temperature bath maintained at 20 ° C (± 0.5 ° C). The conductivity was calculated. In addition, the distance between terminals was 100 mm.

Regarding bendability, the bend test apparatus shown in FIG. 2 was used. An aluminum alloy strand having a wire diameter of 0.32 mm of the sample 5 is sandwiched between mandrels 6 and a load is applied by hanging a weight 7 of 50 g at the lower end to suppress the deflection of the wire. The upper end portion of the sample 5 is fixed by the connecting tool 8.
In this state, the sheet was bent 30 degrees to the left and right, repeatedly bent at a rate of 100 times per minute, and the number of times of bending until breaking was measured for each sample. The number of bendings was counted as one reciprocation, and the interval between the mandrels 6 was 1 mm so as not to press the sample 5 during the test.
The determination of breakage was made when the weight 7 hung on the lower end of the sample 5 dropped. The mandrel 6 is a mandrel having an arc portion corresponding to a circle having a radius of 90 mm, and it is possible to apply a bending stress corresponding to a radius of 90 mm. The measurement results are shown in Table 1.

Comprehensive evaluation evaluated the material characteristics of tensile strength, flexibility, and electroconductivity, and the environmental characteristics of possibility of weight reduction and recyclability.
Flexibility is 110,000 times or more, Tensile strength is 240 MPa or more, Conductivity is 58.5% IACS or more, Light weight can be lighter than conventional Cu, Recyclability is easy to self-rotate, these “◯” indicates that all of the above are satisfied, “Δ” indicates that the material characteristics are satisfied but the environmental characteristics are not satisfied, and “×” indicates that none of the material characteristics are satisfied. In particular, “◎” indicates that the film has flexibility of 130,000 times or more, tensile strength of 260 MPa or more, conductivity of 60% IACS or more and satisfactory environmental characteristics.

  As is apparent from Table 1, Example No. of the present invention. 1-No. No. 16 has excellent flexibility, tensile strength, and conductivity, and can fully utilize the lightness and recyclability of the aluminum alloy.

  On the other hand, the conventional example No. In 100, the flexibility and the like are excellent, but because it is made of Cu alloy, it is heavy and inferior in recyclability. Conventional Example No. Since 101 is a pure aluminum electric wire, its flexibility is greatly inferior. Comparative Example No. 1 which is an aluminum alloy strand having a component composition according to Invention Example 1 described in Patent Document 4. No. 102 has a conductivity as low as 56.0% IACS.

Comparative Example No. In No. 20, since each content of Fe, Si, and Mg is small, the flexibility is greatly inferior. Comparative Example No. with low Fe content 21, no. In Inventive Sample No. 22, the Si and Mg contents are the same. 2, no. As can be seen from FIG. Moreover, Comparative Example No. with a large content of Fe. 29, no. At 30, a decrease in conductivity is observed.
Comparative Example No. with low Si content 23, Example No. of the present invention having the same Fe and Mg contents Compared to 5, the flexibility is greatly reduced and the conductivity is also inferior. Comparative Example No. with a high Si content 25, no. In 28, the conductivity is decreased.
Comparative Example No. with low Mg content 24, no. No. 26, Example No. of the present invention having the same Fe and Si contents. 7, no. The flexibility is significantly lower than 10. Comparative Example No. with a high Mg content 27 shows that the conductivity is decreased.

(Example 2)
Invention Example No. 1 of Table 1 prepared in Example 1 was used. 1 and no. 9 is twisted and coated with a non-halogen resin to produce an aluminum conductive wire as shown in FIG. 1 (c). The tensile strength is the same as in Example 1. As a result, values of 193 MPa and 221 MPa were obtained, respectively. This value satisfies the reliability of the connection portion between the aluminum conductive wire and the terminal when assembled to an automobile.

(Example 3)
Invention Example No. 1 in Table 1 having a wire diameter of 0.32 mm produced in Example 1 was used. 9, Conventional Example No. No. 100 copper wire and conventional example No. 102 of Al-0.4Fe-0.3Mg-0.3Si alloy wire to twist each respectively seven, to produce the strands of the conductor area 0.5 mm ^2, further respectively after applying a resin coating on the line A sample of 30 bundles and a PVC tape was prepared, and the flexibility was evaluated using this sample.
FIG. 3 is an explanatory diagram of the flexibility test method. A sample 11 having a length of 350 mm is placed on a mandrel 10 having a diameter of 19 mm of a support body set to a support interval of 100 mm of the two-point support flexibility test jig 9 on the mandrel. The pulling strength of the sample 11 was measured by pulling the middle part of both mandrels downward using a tensile tester (not shown), and the flexibility was evaluated.
Invention Example No. The pulling strength of No. 9 is 15.7 N, the conventional example No. of copper wire. No. 100 is 13.6 N, and the conventional example No. It becomes 21.6N at 102, and the flexibility of the aluminum conductive wire according to the present invention is almost the same as that of the copper wire, and it can be seen that the flexibility is significantly improved as compared with the conventional aluminum conductivity.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing of the aluminum conductive wire which shows an example of the embodiment of the aluminum conductive wire which concerns on this invention, (a) The aluminum conductive wire which resin-coated the strand wire which consists of 19 aluminum alloy strands, (b) It is an aluminum conductive wire in which a stranded wire made of an aluminum alloy wire is coated with a resin. (C) An aluminum conductive wire in which a compression conductor stranded wire composed of seven aluminum alloy wires is coated with a resin. It is explanatory drawing of the flexibility test used by this invention. It is explanatory drawing of the softness | flexibility test method used by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Aluminum conductive wire 2 Stranded wire 2a Compression conductor strand 3 Aluminum alloy strand 4 Coating resin 5 Sample (aluminum alloy strand)
6 Mandrel 7 Weight 8 Connector 9 Two-point support type flexibility test jig 10 Mandrel 11 Sample

Claims (3)

Fe and 1.10~1.50mass%, Mg of 0.05~0.25mass%, the Si containing 0.02~0.06mass%, continuous casting and rolling method aluminum alloy the balance being Al and unavoidable impurities by then pressing factory to roughing line, the roughing line processed cold drawing up diameter 2.6mm, 2 hours heat treatment the tensile strength in the diameter 2.6mm is less 150MPa temperature 350 ° C. An aluminum alloy wire having a wire diameter of 0.07 to 1.50 mm obtained by further cold working is used as a strand, and the strand is equivalent to a radius of 90 mm and is 100 times / minute. The aluminum conductive wire for automobile wiring , wherein the number of times of bending until breakage in the reciprocating bending is 110,000 times or more, and the strands are twisted together .   The aluminum conductive wire for automobile wiring according to claim 1, wherein the strand has a tensile strength of 240 MPa or more. An automotive wiring electric wire obtained by further coating the aluminum conductive wire for automotive wiring according to claim 1 with a tensile strength of 140 MPa or more.

Images