JP5463618B2 - Automotive wire harness - Google Patents

Description

  The present invention relates to a wire harness for an automobile, and is intended to reduce the weight of a wire harness composed of a plurality of electric wire groups in order to improve the fuel efficiency of the automobile.

Conventionally, as a conductor (core wire) material of an electric wire used for an automobile wire harness, a copper-based material, in particular, an annealed copper material is used from the viewpoint of high conductivity, easy cost acquisition, and ease of use. It has been.
Recently, fuel efficiency of automobiles has been improved as part of environmental measures, and weight reduction of wire harnesses has been strongly demanded.
As one of the weight reductions of the wire harness, the applicant has proposed that the conductor material be replaced with an aluminum-based metal having a specific gravity lighter than that of the copper-based material from the viewpoint of reducing the weight of the electric wire constituting the wire harness.

  For example, in Japanese Patent Application Laid-Open No. 2005-93301 (Patent Document 1), as shown in FIG. 8, the second type made of pure aluminum or aluminum alloy is disposed around the central strand 1a of the first type material made of aluminum alloy. There is provided an automobile electric wire 1 in which a peripheral strand 1b of material is arranged, the hardness of a first type material is made larger than the hardness of a second type material, and a central reinforcing portion is provided.

  An electric wire (hereinafter referred to as an aluminum electric wire) in which the conductor material having the above-described configuration is an aluminum-based metal is compared with an electric wire in which a conventional conductive material is a copper-based metal material (hereinafter referred to as a copper electric wire). (Core wire) can be reduced in weight, and in the case of the same conductor cross-sectional area, since the insulating coating layer having the same thickness is provided, the weight of the electric wire itself can be reduced.

However, since the aluminum-based material has a lower electrical conductivity than the copper-based material, the conductor cross-sectional area of the aluminum electric wire is larger than the conductor cross-sectional area of the copper electric wire when the electric wire has the same amount of current.
The circuit composed of the wire harness consists of a power circuit, a signal circuit, and a ground circuit. The electric wires for these circuits are a power line, a signal line, and a ground line. Among these, the power line and the ground line have a relatively large current. Need to flow. When these power lines and ground wires that carry large currents are replaced with aluminum wires, the electrical conductivity of copper wires having the same cross-sectional area is about 30 to 60% and the conductor resistance is 1.3 to 1.7 times. . Therefore, when substituting with an aluminum electric wire, it is necessary to increase the conductor cross-sectional area by one or two sizes so that the conductor resistance becomes approximately the same.
In addition, the size (mm ² ) of the conductor cross-sectional area of the electric wire used in the automobile wiring harness is [0.3], [0.5], [0.85], [1.25], [ 2], [3], [5], [8], [10], [12], [15], [20], [30], and the increased cross-sectional area by one size up is not constant . In the ISO standard as well, the increased area is not constant. The wire size configuration used for automobiles may be selected from the optimum wire sizes of JASO and ISO, and is not necessarily unified by any standard.

The number of wire harnesses to be routed in an automobile is dozens even if there are few, and several hundreds if there are many, and it is related to the size of the wires constituting these wire harnesses. However, when all are comprised with an aluminum electric wire, the outer diameter of a wire harness may become very large compared with the wire harness which consists of a conventional copper electric wire.
In addition, the thickness of the insulation coating layer of the electric wire needs to be increased every several steps in accordance with the JASO standard or the ISO standard. Therefore, as described above, when the conductor cross-sectional area of the aluminum electric wire exceeds the cross-sectional area of the boundary that increases the thickness of the insulating coating layer, the thickness of the insulating coating layer also increases. In this respect as well, the wire size increases and the weight increases by the thickness increase of the insulating coating layer.

JP-A-2005-93301

As described above, if the conductor material is changed from the copper-based material to the aluminum-based material, the weight of the conductor of the electric wire can be reduced. However, when viewed as a whole of a wire harness composed of a group of various sizes of electric wires, there is a problem that the outer diameter of the wire harness increases while the effect of reducing the weight is poor.
In general, the wiring route in a car is designed on the premise of copper wires, and the surrounding on-board equipment is also designed on the premise thereof. When the outer diameter increases, it becomes difficult to secure a wiring space for the wire harness. In particular, recently, the wiring harness wiring space is restricted due to the rapid increase of various electrical components in the automobile, and the wiring harness wiring with an increased outer diameter may not be spatially possible.
Furthermore, when the outer diameter of the wire harness increases, the wire harness becomes difficult to handle, and the assembly performance to the vehicle also deteriorates.

  The present invention has been made in view of the above problems, and from the viewpoint of a wire harness that focuses a large number of electric wire groups, considering the conductor area based on the allowable current amount of each electric wire constituting the wire harness, An object is to reduce the overall weight of the wire harness and to suppress an increase in the outer diameter of the wire harness.

In order to solve the above-mentioned problems, as a first invention, a plurality of electric wires covering conductors having different conductor cross-sectional areas with insulating coating layers having different thicknesses corresponding to the conductor cross-sectional areas are converged. A wire harness for automobiles formed as
When the conductor was a copper or copper alloy, electric wire Hosobutsu wire conductor cross-sectional area is 0.35mm ² ~1.25mm ^2, conductor cross-sectional area of the wire is less than 8 mm ² beyond the 1.25 mm ² A middle wire, a wire having a conductor cross-sectional area of 8 mm ² or more is a thick wire, and the total proportion of the thin wire and the thick wire is 95% or more in the composition ratio of the wires of the wire harness. The electric wire which comprises comprises the wire harness for motor vehicles characterized by consisting only of the aluminum electric wire which a conductor consists of aluminum or an aluminum alloy.
According to a second aspect of the present invention, a plurality of electric wires are formed by converging a conductor having a different conductor cross-sectional area with an insulating coating layer having a different thickness corresponding to the conductor cross-sectional area. A wire harness for automobiles,
When the conductor was a copper or copper alloy, electric wire Hosobutsu wire conductor cross-sectional area is 0.35mm ² ~1.25mm ^2, conductor cross-sectional area of the wire is less than 8 mm ² beyond the 1.25 mm ² midsole wire, conductor cross-sectional area and Futomono wire the wire is 8 mm ² or more, the fine product in the component ratio of the wire harness wire wire the fine product more than 80% and in the component ratio of the electric wire of the wire harness The total of the electric wire and the thick wire is less than 92% , the thin wire and the thick wire are aluminum wires whose conductor is made of aluminum or an aluminum alloy, and the intermediate wire is a copper whose conductor is made of copper or a copper alloy The present invention provides an automobile wire harness characterized in that the wire harness is composed of two types of wires.

Wires, as described above, fine material wire conductor cross-sectional area of 0.35mm ² ~1.25mm ^2, midsole wire conductor cross-sectional area of 1.5 mm ² to 5 mm ^2, the conductor cross-sectional area which constitutes a wire harness There has been focusing a variety of wire and 8 mm ² or more Futomono wire. In wire harnesses that are routed in automobiles, the ratio of the thin wire is often 80% or more, and more preferably 95% or more due to an increase in signal circuits and the like.
In addition, conductor cross-sectional area [mm < ² >] is a cross-sectional area of the conductor inscribed in the insulation coating layer of an electric wire, and when a conductor is comprised by bundling several strands, it is the total cross-sectional area.

2. Description of the Related Art Conventionally, as an electric wire constituting a wire harness, a copper electric wire in which a core wire (conductor) formed by twisting a strand made of a soft copper material is covered with an insulating coating layer is used.
When the conductor cross-sectional area of the copper wire and the aluminum wire is the same, the weight can be reduced when the conductor is made of an aluminum-based metal rather than a copper-based metal. However, it is necessary to increase the conductor cross-sectional area by one or two sizes as an aluminum-based metal, and the weight is reduced depending on the wire size compared to the case of using a copper-based conductor with a small cross-sectional area with the same allowable current amount. However, there is a drawback that the outer diameter of the electric wire is increased.
Also, JASO and ISO stipulate that the thickness of the insulating coating layer covering the conductor is changed stepwise according to the thickness of the conductor cross-sectional area. When the area exceeds the boundary point that changes the thickness of the insulating coating layer, the rate of increase in the outer diameter of the wire increases.

  In the present invention, as described above, the weight reduction rate, the outer diameter increase rate, the weight of the insulating coating layer and the outer diameter increase rate when the conductor material is aluminum, and the ratio of the size of the electric wire constituting the wire harness. Taking all into consideration, the aluminum wire and the copper wire are properly used, so that the light weight effect of the wire harness appears remarkably and the increase rate of the outer diameter of the wire harness can be suppressed.

That, in the second invention, and the fine material wire 80% or more and the component ratio of the electric wire of the wire harness of the copper wire is a wire harness conductor cross-sectional area is in the range of 0.35 mm ² ～1.25Mm ² the sum of the Futomono wire with less than 92%, has a base with copper wire to the Said sub product lines and Futomono wire is replaced with the aluminum wire. This is because the aluminum wire has a large weight reduction rate of the conductor itself as compared with the copper-based conductor, and also has a low cross-sectional area increase and an outer diameter increase rate including the insulating coating layer. On the other hand, the allowable current amount of wires forming the wire harness is less than 8 mm ² conductor cross-sectional area beyond the 1.25 mm ² other than the range of copper wire wire, the electric wire and copper wire, and a copper wire The wire harness is comprised with the aluminum electric wire.

As described above, if the cross-sectional area of copper wires to replace the range of 0.35mm ² ~1.25mm ^2, the aluminum electric wire conductors of the wire was replaced with an aluminum-based conductor, a copper wire and the same allowable current amount In order to ensure, the conductor cross-sectional area may be increased by one size or two sizes. Accordingly, in the aluminum electric wire cross-sectional area of copper wires is replaced with ^{0.35mm 2 ~1.25mm 2, 0.5mm 2 ~1.5mm} 2 of one size up conductor cross-sectional area of the aluminum-based conductors or two sizes, if the up is set to 0.75mm ² ~2.0mm ^2.
Incidentally, for example, if the wire conductor cross-sectional area is permissible current value is 0.35 mm ² to 0.5 mm ² signal circuit is several mA (micro current) ～11A about, substituted copper wire to an aluminum electric wire In this case, the conductor cross-sectional area may be set to 0.35 mm ² or 0.5 mm ² , so that it is not necessary to increase the size.
In other words, the conductor cross-sectional area of the aluminum conductors can be in the range of 0.35 mm ² 1.5 mm ^2.

Wherein the wire harness of the first aspect of the invention, the electric wire a Hosobutsu wire conductor cross-sectional area is 0.35mm ² ~1.25mm ^2, conductor cross-sectional area of the wire is less than 8 mm ² beyond the 1.25 mm ² A middle wire, a wire having a conductor cross-sectional area of 8 mm ² or more is a thick wire, and the total proportion of the thin wire and the thick wire is 95% or more in terms of the composition ratio of the wire harness. All electric wires of the wire harness are replaced with aluminum electric wires, including thick electric wires having a cross-sectional area of 8 mm ² or more.
The unit mass [g / m] by size of the copper wire and the aluminum wire and the light weight effect [g / m] when the copper wire is replaced with the aluminum wire are the same as the copper wire as shown in the graph described later. In order to ensure the allowable current amount, even if the aluminum wire is increased by at least one size and thickened, the light weight effect can be ensured. In some cases.
In particular, the weight effect per unit length when the copper electric wire is replaced with an aluminum electric wire is larger as the conductor cross-sectional area becomes a thicker size of 8 mm ² or more. Therefore, as described above, when the conductor cross-sectional area is 8 mm ² or more with a copper electric wire, it is replaced with an aluminum electric wire.

In the second invention, automotive wire harnesses, among the electric wires constituting the wire harness, the ratio conductor cross-sectional area in the copper wire of Hosobutsu wire in the range of 0.35 mm ² ～1.25Mm ² Is 80% or more , and when the total of the thin wire and the thick wire is less than 92% in the wire harness wire component ratio, the copper wire of the thin wire and the thick wire is replaced with an aluminum wire. Since the light weight effect becomes remarkable and the increase rate of the outer diameter of the wire harness is small, it can be suitably used.

As described above, in the first aspect of the present invention, among the electric wires constituting the ring ear harness, the proportion of fine material wires within the conductor cross-sectional area of 0.35mm ² ~1.25mm ² is 80% or more and, when Said sub product lines and the conductor cross-sectional area total of 8 mm ² or more Futomono wire is 95% or more, the electric lines constituting the wire harness becomes remarkable lightweight effect that substitution in the aluminum wire, And since the increase rate of the outer diameter of a wire harness is few, it can use suitably.
That is, a thick electric wire having a conductor cross-sectional area of 8 mm ² or more becomes a power line, and only a few wires are included in the wire harness. Even if the outer diameter of the wire harness is increased, the influence is very small, but the effect of reducing the weight by replacing the thick wire with an aluminum wire is great.
In addition, when the composition ratio of the wire size of the wire harness occupies 95% or more of the thin wire and the thick wire, the number of medium wires is very small. When viewed as a whole wire harness, there is an effect of reducing the weight and increasing the outer diameter of the wire harness.

As described above, according to the present invention, in both the first invention and the second invention, in the wire harness composed of many different sized wires, the conductor breakage of the copper wire is included in the wires constituting the wire harness. wire area in the range of 0.35mm ² ~1.25mm ² is, since the aluminum electric wire, lightweight effect and is remarkable, and an increase in the outer diameter ratio of the wire can be suppressed.
In particular, if the conductor cross-sectional area is 0.35 to 0.5 mm ² and the allowable current range is several mA (slight current) to 11 A, the conductor breaks when replacing the copper wire with the aluminum wire. The area may be set to 0.35 mm ² or 0.5 mm ^2, and it is not necessary to increase the size, and the light weight effect appears remarkably. In the case of a minute current, a further light weight effect can be expected by setting the conductor cross-sectional area of all the aluminum wires to 0.35 mm ² .
Further, in the second invention, the electric wire constituting the wire harness uses the aluminum electric wire and the copper electric wire separately according to the conductor cross-sectional area, thereby reducing the increase in the outer diameter of the wire harness and reducing the weight of the wire harness. Can be achieved.

An embodiment of an automotive wire harness according to the present invention will be described.
As shown in FIG. 1A, the wire harness of the present invention is a wire harness W in which several tens to several hundreds of electric wires 10 formed by covering conductors 11 having different conductor cross-sectional areas with an insulating coating layer 12 are concentrated. / H. The wire harness W / H includes an instrument panel harness, a floor harness, an engine room harness, a roof harness, a door harness, and the like that are routed in an automobile.

As shown in FIG. 1B, the wire harness W / H of the first embodiment includes an aluminum electric wire 10A whose conductor is made of aluminum or an aluminum alloy and a copper electric wire 10B whose conductor is made of copper or a copper alloy.
In addition, in the wire harness W / H shown in FIG. 1 (B), for ease of explanation, six aluminum wires 10A0, 10A1, 10A2, 10A3 and two copper wires 10B1, 10B2 are used. However, in practice, it is composed of at least 10 wires to several hundred wires as described above.

In the wire harness targeted by the present invention, as shown in the graph of FIG. 2, when all the electric wires are copper electric wires, the structure of the electric wires has a conductor cross-sectional area of 0 in both small cars and medium-sized cars. .35mm ² ~1.25mm occupies about 90% ^2-called Hosobutsu wire, conductor cross-sectional area occupies about 8%-called midsole wire 1.5 to 5 mm ^2, the conductor cross-sectional area 8 mm ² or more The so-called thick wire that exceeds is less than 2%.
From this point, when the weight of the fine wire occupying nearly 90% of the wire harness is reduced, the weight reduction of the entire wire harness is promoted.

In the present embodiment, when a copper wire, Futomono wire conductor cross-sectional area is 0.35 mm ² or more 1.25 mm ² or less fine material wire and conductor cross-sectional area of 8 mm ² or more, without the copper wire, The aluminum electric wire 10A is replaced. When the copper-based conductor is replaced with an aluminum-based conductor, the conductor cross-sectional area may need to be increased by one size or two sizes.
During FIG. 1 (B), the aluminum electric wire 10A0 is a wire for signal circuits, obtained by replacing wires 0.35 mm ² of copper-based conductor cross-sectional area of aluminum electric wire remains 0.35 mm ^2, the size no up It is the composition of. The aluminum electric wire 10A1 is an electric wire for a small current power supply circuit other than a signal circuit electric wire (electric wire applied to a current value of several mA to 11A), and an electric wire having a copper-based conductor cross-sectional area of 0.35 mm ² is an aluminum electric wire. The aluminum-based conductor cross-sectional area is 0.5 mm ² which is one size up. The aluminum electric wire 10A2 is a copper-based conductor cross-sectional line in which a 1.25 mm ² electric wire is replaced with an aluminum electric wire, and the aluminum-based conductor cross-sectional area is 1.5 mm ² that is one size up. The aluminum electric wire 10A3 has a copper-based conductor cross-sectional area in which an 8 mm ² electric wire is replaced with an aluminum electric wire, and the aluminum-based conductor cross-sectional area is increased to 12 mm ² by 2 sizes.
On the other hand, copper-based conductor cross-sectional area is the midsole wire is a wire of less than 8 mm ² beyond the 1.25 mm ² and copper wire 10B. In FIG. 1 (B), the conductor cross-sectional area of the copper electric wire 10B1 is 2 mm ² , and 10B2 is 5 mm ² .
In these electric wires, when the conductor cross-sectional area is less than 2 mm ² (up to 1.5 mm ² ), the thickness of the insulating coating layer is 2 mm, and when the conductor cross-sectional area is 2 mm ² or more and 3 mm ² or less, the thickness of the insulating coating layer is 0.35 mm. When the conductor cross-sectional area exceeds 3 mm ² , the thickness of the insulating coating layer is set to 0.7 mm.
In addition, when there is an extra fine wire less than 0.35 mm ² , the conductor weight is very small, so it is an aluminum wire or a copper wire.

  The reason why the aluminum wire 10A and the copper wire 10B are properly used according to the conductor cross-sectional area as described above will be described in detail below.

First, FIG. 3A shows the rate of increase in the outer diameter of the wire when the copper wire is replaced with an aluminum wire in order from the smallest conductor cross-sectional area. 100% is in a state where it is not replaced with an aluminum electric wire.
As shown in figure 3 (A), but the rate of increase in outer diameter of the wire when the copper conductor cross-sectional area to replace the 0.35mm ² ~1.25mm ² aluminum wires can be suppressed to 5%, If it exceeds 1.25 mm ² , the rate of increase in outer diameter will rise rapidly.

FIG. 3B shows the weight reduction rate when the copper wire is replaced with an aluminum wire. 100% is in a state where it is not replaced with an aluminum electric wire.
From FIG. 3B, when the conductor cross-sectional area is 0.35 mm ² , it is reduced by about 10%, and the weight reduction effect is recognized by the replacement with the aluminum electric wire. This particular wire (e.g., wire for an air bag circuit through which a current larger than the fine current) an electric wire conductor cross-sectional area of 0.35 mm ² except, substituted conductor cross-sectional area of the aluminum electric wire 0.35 mm ² Therefore, the light weight effect is remarkable as compared with the copper-based conductor wire.

Figure 3 (C) and the weight loss and showing the correlation between the outer diameter increment size, from the relationship between the two, the weight loss and the balance between the outer diameter increment size, the copper-based conductor cross-sectional area of 0.35mm ² ~1.25mm ² Has been found to be optimal replacement with aluminum wires.

Furthermore, it explains in full detail using FIGS. 4-6.
In the graph of FIG. 4, a horizontal axis shows the cross-sectional area of the copper-type conductor of the copper electric wire before substitution to an aluminum electric wire. When replacing with an aluminum wire having the same allowable current amount as that of the copper wire, the cross-sectional area of the aluminum-based conductor may be increased by one size or two sizes.
Increased cross-sectional area (mm ²⁾ by subtracting the cross-sectional area of the copper electric wire before the replacement to the aluminum electric wire from the cross-sectional area of the aluminum electric wire per replacement (the cross-sectional area of the aluminum conductor + the insulating coating cross-sectional area) ) Is shown on the vertical axis.
In FIG. 4, the case where the copper wire is increased to one size by an aluminum wire is indicated by-♦-, and the case where the size is increased by 2 is indicated by-■-.
Even if the size is increased by one size, the absolute value of the cross-sectional increase is not constant because the raising width differs depending on the conductor cross-sectional area.

As shown in the graph of FIG. 4, if the conductor cross-sectional area of the copper wire before the replacement of the aluminum wire in the fine material wires consisting of 0.35mm ² ~1.25mm ^2, which was replaced with an aluminum wire with one size up The cross sectional area of the conductor is 0.5 to 1.5 mm ^{2 and the} increasing cross sectional area is small. And if it is a circuit for fine electric current, a copper electric wire with a conductor cross-sectional area of 0.35 mm ² can be replaced with an aluminum electric wire with a conductor cross-sectional area of 0.35 mm ² without increasing the size. For this reason, even if a thin wire is replaced with an aluminum wire, the rate of increase in the outer diameter of the wire is very small.
On the other hand, the cross-sectional area conductor cross-sectional area of the copper wire before the replacement is to increase when the substitution of the aluminum wire in midsole wire up to 5 mm ² over a 1.25 mm ² is increased. Furthermore, between ^{8 mm} 2 to 10 mm ² in Futomono wire exceeding 5 mm ^2, once the increase in cross-sectional area is being suppressed, will generally cross-sectional area is increased.

In the graph of FIG. 5, a horizontal axis shows the cross-sectional area (mm < ² >) of the copper-type conductor of a copper electric wire. Replace with an aluminum-based conductor so that it has the same allowable current amount as the conductor of the copper wire, and coat the aluminum-based conductor with an insulating coating layer to form an aluminum wire. Wire size (conductor cross-sectional area + insulating coating layer cross-sectional area) Shows the light weight effect (g / m) on the vertical axis when 1 size up and 2 size up aluminum wires are provided and replaced with this aluminum wire.
In FIG. 5, the case where the copper wire is increased to one size by an aluminum wire is indicated by-♦-, and the case where the size is increased by 2 is indicated by-■-.

In this embodiment, if the thickness of the insulating coating layer covering the conductor, the conductor cross-sectional area up to 1.5 mm ² while the thickness of the insulating coating layer is 0.2, exceeding 1.5 mm ² is The thickness of the insulating coating layer is set to 0.35 mm. Then, an aluminum electric wire to be a wire or a small-current power supply circuit for the signal circuit, the cross-sectional area of the conductor made of aluminum or aluminum alloy is 0.35 mm ² 1.5 mm ^2, an insulating coating layer covering the aluminum conductor The thickness is set to 0.2 mm.
The thickness of the insulating coating layer covering the conductor is based on the JASO standard. For example, the thickness of the insulating coating layer is less than 2 mm ^{2 and} the thickness of the insulation coating layer is 0.2 mm, 2 mm ² or more and less than 3 mm ² For thick wires exceeding 0.35 mm and 3.0 mm ² , the thickness may be 0.7 mm.
As described above, when the conductor cross-sectional area at the boundary changing from a thin wire to a medium wire exceeds 1.5 mm ² , the insulation coating thickness becomes 0.35 mm, and the outer diameter increase rate of the wire rapidly increases accordingly. Further, the weight per unit length of the electric wire also increases due to the increase in the thickness of the insulating coating layer.

  In FIG. 5, 0.0 on the vertical axis indicates that the weight when replaced with an aluminum wire is the same as that of a copper wire. For example, “−20.0” is − 20.0 g / m Lightweight.

As shown in the graph of FIG. 5, even if the copper wire is replaced with an aluminum wire and the size is increased by one to increase the size of the wire, the weight per unit length is greater than that of the copper wire in any cross-sectional area. Aluminum wires can reduce the weight and achieve a light weight effect.
The fine product wire conductor cross-sectional area of 0.35mm ² ~1.25mm ^2, when substituted on an aluminum electric wire, as shown in FIG. 4, less the increase in the wire cross-sectional area, and, as described above, Since there is a light weight effect, the thin wire replaces the copper wire with the aluminum wire in this embodiment. In particular, since the proportion of the fine wires in the wire harness is around 90% as shown in FIG. 2, even if the effect of reducing the weight of one wire is low, the effect of reducing the weight is large in the whole wire harness. .

On the other hand, when the conductor cross-sectional area of the copper wire is 2 mm ² , the light weight effect is small when the aluminum wire is replaced by one size up.
Moreover, when the conductor cross-sectional area of a copper electric wire is 1.5-5 mm < ² >, when the aluminum electric wire is increased in size by 2 and replaced, the weight per unit length is increased as compared with the copper electric wire. That is, when the conductor cross-sectional area of the copper electric wire is 1.5 to ⁵ mm2, there is no light weight effect and the weight increases.
Thus, a point light ineffective, from the viewpoint large increase of the conductor cross-sectional area in the case of copper conductors as shown in FIG. 3 and aluminum conductors, less than 8 mm ² conductor cross-sectional area beyond the 1.25 mm ² The wires are copper wires.

In addition, in the case of a thick wire in which the conductor cross-sectional area of the copper wire before the replacement with the aluminum conductor exceeds 8 mm ² , both in the case of 1 size up and in the case of 2 size up, the unit length is longer than that of the copper wire. The weight reduction rate is very high.
In the thick wire, the outer diameter increase rate increases as shown in FIG. 3, but the thick wire is 3% or less of the wire occupying the wire harness as shown in FIG. The influence of the increase in the outer diameter of the thick wire on the outer diameter of the entire wire harness is minor.
Therefore, a thick electric wire having a conductor cross-sectional area exceeding 8 mm ² is an aluminum electric wire because the weight reduction rate is high.

The graph of FIG. 6 shows the relationship between the total wire weight of the wire harness and the outer diameter of the wire harness when the copper wire is replaced with an aluminum wire in the wire harness composed of the group of wires shown in Table 1 below.
In the graph of FIG. 6, the horizontal axis is the conductor cross-sectional area of the copper wire before the replacement with the aluminum wire, the left vertical axis is the weight of the wire harness when the copper wire is replaced with the aluminum wire, and the right vertical axis is the aluminum wire of the copper wire. The outer diameter of the wire harness at the time of replacing with an electric wire is shown. In addition, as for the replaced aluminum electric wire, what increased 1 size with respect to the size of a copper electric wire and what increased 2 sizes are mixed.

表１に示す電線サイズは、アルミニウム電線に置換前の銅線の銅系導体のサイズで示しており、この場合のワイヤハーネスの合計重量は４２６４ｇである。
なお、ワイヤハーネスを構成する電線群は、全電線を同一長さとして結束しているものではないため、長さ方向において各部の断面積、外径は同一ではないが、表１に示すワイヤハーネスでは長さ方向における中央部の径はφ２４．６ｍｍである。

The electric wire size shown in Table 1 is shown by the size of the copper-based conductor of the copper wire before replacing the aluminum electric wire, and the total weight of the wire harness in this case is 4264 g.
In addition, since the electric wire group which comprises a wire harness does not bind all the electric wires as the same length, although the cross-sectional area of each part and an outer diameter are not the same in a length direction, the wire harness shown in Table 1 Then, the diameter of the central part in the length direction is φ24.6 mm.

As shown in the graph of FIG. 6, since the copper wire exceeding copper conductor cross-sectional area 1.25 mm ² are the cross-sectional area and 2.0 mm ² is replaced with an aluminum wire, 0.35 mm thickness of the insulating coating layer Therefore, the outer diameter (thickness) of the wire harness is rapidly increasing.
From this result, it can be confirmed that it is preferable to keep the copper wires as those belonging to the intermediate wire having a copper-based conductor cross-sectional area exceeding 1.25 mm ² .
On the other hand, the number of thin wires of 0.5 mm or less is 479, accounting for 88% of the total number of 543 wires, and by replacing this with aluminum wires, the reduction rate of the wire weight of the wire harness is large. It has become. From this result, it can confirm that the effect which replaces the thin wire | line which occupies 80% or more in the wire group which comprises a wire harness with an aluminum wire is large.
Thus, wires ranging conductor cross-sectional area of 0.35mm ² ~1.25mm ² with copper wire and aluminum wire, the conductor cross-sectional area wire of less than 8 mm ² beyond the 1.25 mm ² are copper wires Thus, it is possible to achieve a good balance between weight reduction and suppression of increase in outer diameter when viewed as a whole wire harness.

In FIG. 7, 2nd embodiment of the wire harness for motor vehicles of this invention is shown.
In the wire harness of the second embodiment, the wire harness is formed from a thin wire 10A which is an aluminum wire.
That is, all the fine material wires that need to copper-based conductor cross-sectional area and 0.35 mm ² or more 1.25 mm ² or less are substituted with aluminum wire.
These fine wires are mainly used for signal circuits. Recently, a large number of electronic control units are mounted on automobiles, and signal wires connected to these electronic control units are made of thin wires, so that wire harnesses made only of aluminum wires are used.

As described above, if the conductor cross-sectional area before the aluminum substitution of 0.35mm ² ~1.25mm ^2, 1 size up aluminum wire, excellent light effect in either case of two sizes up, and the outer diameter The increase rate is suppressed to 5% or less. Therefore, in the wire harness of the second embodiment, weight reduction can be achieved as compared with the case where a wire harness made of a copper electric wire is configured.
And if all the electric wires which comprise a wire harness are aluminum electric wires, at the time of recycling of a wire harness, copper material mixing into a steel material can be prevented and the quality improvement of a recycled steel material can be aimed at.

  In both the first and second embodiments, when a shielded electric wire and a coaxial cable are included, the outer diameter of the electric wire increases because the outer diameter of the electric wire includes a shield layer and a sheath. Even in the case of a cross-sectional area, it is preferable to use a copper wire without replacing the aluminum wire with an increased outer diameter.

(A) is the schematic which shows the wire harness for motor vehicles of 1st embodiment, (B) is an expanded sectional view of this wire harness. It is a graph which shows the ratio of the electric wire size which occupies for a wire harness. (A) is a diagram showing the rate of increase in the outer diameter of the wire when the copper wire is replaced with an aluminum wire, (B) is a diagram showing the rate of decrease in the weight of the wire when the copper wire is replaced with an aluminum wire, (C (A) and (B) are diagrams showing the optimum range of replacement with aluminum wires from (A) and (B). It is a graph which shows the electric wire cross-section increase at the time of substituting to the aluminum electric wire from a copper electric wire in detail. It is a graph which shows the mitigation effect at the time of substituting for an aluminum electric wire from a copper electric wire in detail. It is a graph which shows in detail the lightweight effect and outer-diameter change of a wire harness at the time of replacing with an aluminum electric wire. It is an expanded sectional view of the wire harness of a second embodiment. It is sectional drawing which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Electric wire 10A Aluminum electric wire 10B Copper electric wire 11 Conductor 12 Insulation coating layer W / H Wire harness

Claims (3)

It is a wire harness for automobiles in which a plurality of electric wires are formed by converging a conductor having a different conductor cross-sectional area with an insulating coating layer having a different thickness corresponding to the conductor cross-sectional area. Te, when the conductor was a copper or copper alloy, the wire conductor cross-sectional area is 0.35mm ² ~1.25mm ² Hosobutsu wire, conductor cross-sectional area is less than 8 mm ² beyond the 1.25 mm ² The electric wire is a medium electric wire, the electric wire having a conductor cross-sectional area of 8 mm ² or more is a thick electric wire, and the total of the fine electric wire and the thick electric wire is 95% or more in the composition ratio of the electric wire of the wire harness, A wire harness for automobiles, wherein the wire constituting the harness is composed only of an aluminum wire whose conductor is made of aluminum or an aluminum alloy. It is a wire harness for automobiles in which a plurality of electric wires are formed by converging a conductor having a different conductor cross-sectional area with an insulating coating layer having a different thickness corresponding to the conductor cross-sectional area. Te, when the conductor was a copper or copper alloy, the wire conductor cross-sectional area is 0.35mm ² ~1.25mm ² Hosobutsu wire, conductor cross-sectional area is less than 8 mm ² beyond the 1.25 mm ² midsole wire the wire, the conductor cross-sectional area and Futomono wire the wire is 8 mm ² or more, the fine product lines in the component ratio of the wire harness wires 80% or more and the configuration ratio of electric wires of the wire harness The total of the thin wire and the thick wire is less than 92% , the thin wire and the thick wire are aluminum wires whose conductor is made of aluminum or aluminum alloy, and the medium wire is made of copper or copper alloy. Copper power And then, automotive wiring harness, characterized in that it constitutes a wire of a wire harness in two types of wire. The fine material wire is set to the aluminum electric wire, the conductor sectional area of an aluminum conductor is 0.35 mm ² 1.5 mm ^2, the thickness of the insulating coating layer covering the aluminum conductor is 0.2mm according The automobile wire harness according to claim 1 or 2.

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