JP2012142310A - Electric wire - Google Patents

Abstract

Provided is an electric wire capable of preventing a strand made of aluminum or an aluminum alloy from being broken even when used for a wire harness routed in an automobile.
An electric wire includes a core wire that is formed by twisting a plurality of strands of compressed conductors made of aluminum or an aluminum alloy, and an insulating covering portion that covers the core wire. The twist pitch of the plurality of strands 5 of the core wire 3 is not less than 3 times and not more than 30 times the core diameter of the core wire 3.
[Selection] Figure 4

Description

  The present invention relates to an electric wire provided with a core wire in which an element wire is made of aluminum or an aluminum alloy.

  In order to reduce the weight of wire harnesses that are conventionally routed in automobiles, it has been proposed that the core wire of an electric wire generally made of copper or a copper alloy be made of aluminum or an aluminum alloy (for example, a patent) Reference 1). The above-described electric wire is attached to a terminal core wire by crimping a terminal metal fitting to constitute the above-described wire harness.

JP 2009-170315 A

  The above-described aluminum or aluminum alloy has lower mechanical strength than copper or copper alloy that has been conventionally used as a material for the core of electric wires. For this reason, when an electric wire provided with a strand made of aluminum or an aluminum alloy is used for a wire harness routed in the automobile described above, it is used for a portion that is repeatedly bent in an automobile such as a door portion, for example. At this time, it is conceivable that the core wire of the electric wire described above breaks.

  Accordingly, an object of the present invention is to provide an electric wire that can prevent a strand composed of aluminum or an aluminum alloy from breaking even when used in a wire harness routed in an automobile.

  In order to solve the above-mentioned problems and achieve the object, the electric wire of the present invention according to claim 1 is a core wire constituted by a plurality of strands of compressed conductors made of aluminum or aluminum alloy, An electric wire including an insulating covering portion that covers a core wire, wherein the twist pitch of the plurality of strands of the core wire is not less than 3 times and not more than 30 times the outer diameter of the core wire. .

  The electric wire according to a second aspect of the present invention is the electric wire according to the first aspect, wherein the twist pitch of the plurality of strands of the core wire is not less than 3 times and not more than 20 times the outer diameter of the core wire. It is characterized by.

  The electric wire according to a third aspect of the present invention is the electric wire according to the first aspect, wherein the twist pitch of the plurality of strands of the core wire is not less than 5 times and not more than 15 times the outer diameter of the core wire. It is characterized by.

  According to the electric wire of the present invention described in claim 1, the twist pitch of the plurality of strands of the core wire is not less than 3 times and not more than 30 times the outer diameter of the core wire, compared to the conventionally used twist pitch of the wire. Is much smaller. Thus, the strands of the core wire are twisted together more than the strands of the core wire of the electric wire conventionally used. For this reason, the extra length of the strand which comprises the core wire in an electric wire becomes fully longer than the strand of the core wire of the electric wire conventionally used.

  According to the electric wire of the present invention described in claim 2, the twist pitch of the plurality of strands of the core wire is not less than 3 times and not more than 20 times the outer diameter of the core wire, which has been conventionally used. Since it is much smaller, the extra length of the core wire constituting the core wire in the electric wire is surely sufficiently longer than that of the core wire of the electric wire conventionally used.

  According to the electric wire of the present invention described in claim 3, the twist pitch of the plurality of core wires of the core wire is not less than 5 times and not more than 15 times the outer diameter of the core wire, which has been conventionally used. Since it is much smaller, the extra length of the core wire constituting the core wire in the electric wire is surely sufficiently longer than that of the core wire of the electric wire conventionally used.

  As described above, according to the first aspect of the present invention, the extra length of the wire constituting the core wire in the electric wire is sufficiently longer than that of the core wire of the electric wire conventionally used. Therefore, even if the electric wire is bent repeatedly, the distortion acting on the strands along with the bending can be reduced. Therefore, even when used for a wire harness routed in an automobile, it is possible to prevent the strands made of aluminum or aluminum alloy from breaking.

  According to the second and third aspects of the present invention, the extra length of the wire constituting the core wire in the electric wire is surely sufficiently longer than the strand of the core wire of the electric wire conventionally used. Therefore, even if the electric wire is repeatedly bent, the distortion acting on the strands along with the bending can be reliably reduced. Therefore, even when used in a wire harness routed in an automobile, it is possible to reliably prevent the strands made of aluminum or aluminum alloy from breaking.

It is a perspective view which shows the electric wire concerning the reference example of this invention. It is sectional drawing of the arrow direction which passes along the straight line II of the electric wire shown by FIG. It is a figure which shows the twist pitch of the strand of a core wire. It is a perspective view which shows the electric wire concerning one Embodiment of this invention. It is sectional drawing of the arrow direction which passes along the straight line V of the electric wire shown by FIG. It is a graph which shows the relationship between the magnification of the twist pitch with respect to a layer core diameter, and the frequency | count of bending when measuring the frequency | count of bending at which a strand breaks. It is a graph which shows the relationship between the magnification of the twist pitch with respect to a conductor outer diameter, and the frequency | count of bending when measuring the frequency | count of bending at which a strand breaks. It is a figure for demonstrating the relationship between the electric wire and jig | tool at the time of bending an electric wire repeatedly.

  Hereinafter, the electric wire concerning the reference example of this invention is demonstrated with reference to FIG. As shown in FIGS. 1 and 2, the electric wire 1 according to the reference example of the present invention includes a conductive core wire 3 and an insulating covering portion 4.

  The core wire 3 is composed of a plurality of strands 5. In the illustrated example, 19 strands 5 are provided. Each of the strands 5 is made of aluminum or an aluminum alloy as a conductive metal. The element wire 5 is made of aluminum means that the element wire 5 is made of only aluminum and inevitable impurities, and the element wire 5 is made of an aluminum alloy. It means that the wire 5 is composed of aluminum, another metal and inevitable impurities.

  The element wire 5 is obtained by passing a rod-shaped metal material made of aluminum or an aluminum alloy through a hole of a die (not shown) and drawing it. That is, the strand 5 is formed in a round cross section without being subjected to compression processing.

  Further, the core wire 3 is formed by bundling the above-described plurality of strands 5 and twisting them around the axis core of the core wire 3. That is, the core wire 3 is formed by twisting a plurality of round strands 5. For this reason, the strand 5 which comprises the core wire 3 is wound around mutually in the state curved in the spiral.

The twist pitch A (shown in FIG. 3) of the strand 5 of the core wire 3 is not less than 3 times and not more than 30 times the layer core diameter B (shown in FIG. 2) of the core wire 3. That is, the strands 5 of the core wire 3 are twisted so that the twist pitch A is 3 times or more and 30 times or less the layer core diameter B of the core wire 3. Note that the twist pitch A in the present invention is, as schematically shown in FIG. 3, a predetermined position in the circumferential direction of the core wire 3 of the strand 5 that is spirally curved, and the core wire 3 from the predetermined position. The distance between the predetermined position in the circumferential direction that has returned around the circumference is shown. That is, the twist pitch A indicates a dimension until the strand 5 returns to its original position even after one round. The core diameter B referred to in the present invention is a value obtained by subtracting the outer diameter of one strand 5 from the maximum outer diameter of the core wire 3, that is, a circle passing through the axis of the strand 5 positioned on the outermost periphery. The outer diameter is shown. Furthermore, it is physically impossible for the strand 5 to be less than 3 times the core diameter B of the core wire 3 due to the outer diameter of the strand 5 itself. That is, the core wire 3 formed by twisting a plurality of strands 5 is always twisted so that the twist pitch A is three times or more the layer core diameter B of the core wire 3.

  Moreover, in this reference example, it is desirable that the twist pitch A of the strand 5 of the core wire 3 is not less than 3 times and not more than 20 times the layer core diameter B of the core wire 3. It is desirable that the twist pitch A is 10 times or more and 20 times or less the layer core diameter B of the core wire 3.

  The covering portion 4 is made of an insulating synthetic resin and covers the strand 3. The cross-sectional shape of the covering portion 4 is an annular shape. The above-described core wire 3 is provided with the covering portion 4, and the electric wire 1 is formed in a round cross section. Moreover, the said electric wire 1 has the coating | coated part 4 removed by the terminal 2, and the core wire 3 is exposed.

  The electric wire 1 having the above-described configuration has a terminal fitting (not shown) attached to the core wire 3 exposed at the terminal 2. The terminal fitting is attached to the connector housing, and the connector of the terminal 2 is attached to the wire harness to be assembled in the automobile.

  According to this reference example, the twist pitch A of the plurality of strands 5 of the core wire 3 is not less than 3 times and not more than 30 times the layer core diameter B of the core wire 3, which is larger than the conventionally used twist pitch of wires. Much smaller. Thus, the strand 5 of the core wire 3 is twisted more than the strand of the core wire of the electric wire conventionally used. For this reason, the extra length of the strand 5 which comprises the core wire 3 in the electric wire 1 becomes fully longer than the strand of the core wire of the electric wire conventionally used.

  For this reason, even if the electric wire 1 is bent repeatedly, the distortion which acts on the strand 5 with this bending can be reduced. Therefore, even when used for a wire harness routed in an automobile, the strand 5 made of aluminum or an aluminum alloy can be prevented from breaking.

  Further, when the twist pitch A of the plurality of strands 5 of the core wire 3 is not less than 3 times and not more than 20 times the layer core diameter B of the core wire 3, even if the wire 1 is repeatedly bent, Thus, the distortion acting on the strand 5 can be more reliably reduced. Therefore, even when used in a wire harness routed in an automobile, it is possible to more reliably prevent the strand 5 made of aluminum or aluminum alloy from breaking.

  Further, when the twist pitch of the plurality of strands 5 of the core wire 3 is not less than 10 times and not more than 20 times the layer core diameter B of the core wire 3, even if the wire 1 is bent repeatedly, The distortion which acts on the strand 5 can be reduced further reliably. Therefore, even when used in a wire harness routed in an automobile, it is possible to more reliably prevent the strand 5 made of aluminum or aluminum alloy from breaking.

  Next, the electric wire 1 concerning one Embodiment of this invention is demonstrated with reference to FIG.4 and FIG.5. In addition, the same code | symbol is attached | subjected to the part same as the reference example mentioned above, and description is abbreviate | omitted.

  In the present embodiment, as shown in FIGS. 4 and 5, the core wire 3 is subjected to a compression process for reducing the cross-sectional area in a state where a plurality of strands 5 are twisted together, and the cross-sectional shape of each strand 5 Is formed in a substantially hexagonal shape. That is, the strand 5 which comprises the core wire 3 is a compression conductor. The compressed conductor of the present invention refers to a conductor that has been subjected to compression processing in a direction that reduces the cross-sectional area with a compression die (not shown).

  Moreover, in this embodiment, the twist pitch A of the strand 5 of the core wire 3 is the dimension of 3 times or more and 30 times or less of the outer diameter C (shown in FIG. 5) of the core wire 3. That is, the strands 5 of the core wire 3 are twisted so that the twist pitch A has a dimension that is not less than 3 times and not more than 30 times the outer diameter C of the core wire 3. Furthermore, it is physically impossible that the strand pitch A is less than three times the outer diameter C of the core wire 3 due to the outer diameter of the strand 5 itself. That is, the core wire 3 formed by twisting a plurality of strands 5 is always twisted so that the twist pitch A is three times or more the outer diameter C of the core wire 3.

  Moreover, in this embodiment, it is desirable that the twist pitch A of the strand 5 of the core wire 3 is not less than 3 times and not more than 20 times the layer core diameter B of the core wire 3. The twist pitch A of the core wire 3 is preferably 5 to 15 times the layer core diameter B of the core wire 3.

  According to this embodiment, the twist pitch A of the plurality of strands 5 of the core wire 3 is not less than 3 times and not more than 30 times the outer diameter C of the core wire 3, far from the conventionally used twist pitch of electric wires. Small. Thus, the strand 5 of the core wire 3 is twisted more than the strand of the core wire of the electric wire conventionally used. For this reason, the extra length of the strand 5 which comprises the core wire 3 in the electric wire 1 becomes fully longer than the strand of the core wire of the electric wire conventionally used. For this reason, even if the electric wire 1 is bent repeatedly, the distortion which acts on the strand 5 with this bending can be reduced. Therefore, even when used for a wire harness routed in an automobile, the strand 5 made of aluminum or an aluminum alloy can be prevented from breaking.

  Further, when the twist pitch A of the plurality of strands 5 of the core wire 3 is not less than 3 times and not more than 20 times the outer diameter C of the core wire 3, even if the wire 1 is bent repeatedly, The distortion which acts on the strand 5 can be reduced more reliably. Therefore, even when used in a wire harness routed in an automobile, it is possible to more reliably prevent the strand 5 made of aluminum or aluminum alloy from breaking.

  Further, when the twisting pitch of the plurality of strands 5 of the core wire 3 is not less than 5 times and not more than 15 times the outer diameter C of the core wire 3, even if the wire 1 is repeatedly bent, The distortion acting on the wire 5 can be further reliably reduced. Therefore, even when used in a wire harness routed in an automobile, it is possible to more reliably prevent the strand 5 made of aluminum or aluminum alloy from breaking.

  Next, the inventors of the present invention manufactured electric wires 1 having different twist pitches A, bent the electric wires 1 repeatedly, and measured the number of bendings at which at least one strand 5 was broken. The results are shown in FIGS.

  6 and 7 indicates the magnification of the twist pitch A with respect to the layer core diameter B (or outer diameter C) of the strand 5 of the core wire 3 described above, and the vertical axis indicates that at least one strand 5 is present. The number of times of bending to break is shown. 6 shows the electric wire 1 provided with the core wire 3 made of the strand 5 having a round cross section without being subjected to compression processing on the strand 5 of the reference example described above, and FIG. The electric wire 1 provided with the core wire 3 which the compression processing was given to the strand 5 of embodiment and comprised the strand 5 of a hexagonal cross section is shown.

  When the electric wire 1 is bent repeatedly, as shown in FIG. 8, one end (upper end) of the electric wire 1 is fixed to the jig 20, and a weight 21 is attached to the other end (lower end). 1 is passed between two cylindrical bending jigs 22. Then, the jig 20 is moved toward the one bending jig 22 to bend one end of the electric wire 1 along the outer peripheral surface of the one bending jig 22, and then the jig 20 is moved to the other bending jig. The one end portion of the electric wire 1 is bent along the outer peripheral surface of the other bending jig 22. Thus, the electric wire 1 is repeatedly bent alternately in opposite directions. When the number of times of bending is 1000 times or more, the electric wire 1 has sufficient performance as a wire harness for an automobile.

  According to FIG. 6 and FIG. 7, the twist pitch A of the plurality of strands 5 of the core wire 3 is set to be not less than 3 times and not more than 30 times the layer core diameter B (or outer diameter C) of the core wire 3. The number of times can be 1000 times or more, and when used in a wire harness routed in an automobile, the wire 1 of the above-described embodiment breaks the strand 5 made of aluminum or an aluminum alloy. It has become clear that this can be prevented, that is, the fatigue strength can be improved. Moreover, according to FIG.6 and FIG.7, by making the twist pitch A of the some strand 5 of the core wire 3 into 3 times or more and 20 times or less of the layer core diameter B (or outer diameter C) of the core wire 3. Even when used in a wire harness routed in an automobile, the electric wire 1 of the above-described embodiment can more reliably prevent the strand 5 made of aluminum or aluminum alloy from breaking, that is, fatigue strength. It became clear that it can be improved.

Furthermore, according to FIG. 6, in the electric wire 1 of the reference example described above, the twist pitch A of the plurality of strands 5 of the core wire 3 is 10 times or more and 20 times or less of the layer core diameter B of the core wire 3. In addition, when used in a wire harness routed in an automobile, it has been clarified that the wire 5 made of aluminum or aluminum alloy can be more reliably prevented from breaking, that is, the fatigue strength can be improved. In the electric wire 1 of one embodiment, as shown in FIG. 7, the twist pitch A of the plurality of strands 5 of the core wire 3 is set to 5 times or more and 15 times or less of the outer diameter C of the core wire 3. Even when used in a wired wiring harness, it has been found that the wire 5 made of aluminum or an aluminum alloy can be more reliably prevented from breaking, that is, the fatigue strength can be improved.

  In addition, embodiment mentioned above only showed the typical form of this invention, and this invention is not limited to embodiment. That is, various modifications can be made without departing from the scope of the present invention.

1 Electric Wire 3 Core Wire 4 Covering Part 5 Wire A Twist Pitch C Outer Diameter

In order to solve the above-described problems and achieve the object, the electric wire according to the first aspect of the present invention is a compression process that reduces the cross-sectional area in a state where a plurality of strands made of aluminum or an aluminum alloy are twisted together. In the electric wire comprising the core wire to which the core wire is applied and the insulating covering portion covering the core wire, the twist pitch of the plurality of strands of the core wire is 3 times or more and 30 times the outer diameter of the core wire It is characterized by the following.

Claims (3)

A plurality of strands of compressed conductors made of aluminum or an aluminum alloy are twisted together;
An insulating coating covering the core wire;
In the electric wire with
The electric wire, wherein a twist pitch of the plurality of strands of the core wire is not less than 3 times and not more than 30 times an outer diameter of the core wire.   The electric wire according to claim 1, wherein a twist pitch of the plurality of strands of the core wire is not less than 3 times and not more than 20 times an outer diameter of the core wire.   The electric wire according to claim 1, wherein a twist pitch of the plurality of strands of the core wire is not less than 5 times and not more than 15 times an outer diameter of the core wire.

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