JP7407627B2 - composite cable - Google Patents

Description

The present invention relates to a composite cable, and particularly to a composite cable including two pairs of signal lines and two power lines.

For example, in recent years, vehicles have been equipped with multiple sensors on the wheels due to advanced computerization, and there are power lines inside the vehicle that supply power from the battery to those sensors, and detected signals from the sensors to the ECU. In some cases, signal lines for transmission may be placed in
Conventionally, when these power supply lines and signal lines are arranged inside a vehicle, they are often arranged together by wrapping them with tape or bundling them with cable ties.

In recent years, development of composite cables in which these wires are combined into one cable has been progressing (see, for example, Patent Document 1). Such composite cables include six-core composite cables that include two pairs of signal lines and two power lines (see, for example, Patent Documents 2 and 3).
By combining multiple wires into one composite cable in this way, the space occupied by the wires and cables in the vehicle is reduced compared to when wires are bundled together, which means space saving. There are advantages such as being able to achieve the following.

Patent No. 6219263 Patent No. 6424950 JP 2018-22633 Publication

By the way, in a 6-core composite cable that includes two pairs of signal lines and two power lines, the power line is usually thicker than the signal line, so this is also described in Patent Documents 2 and 3 mentioned above. As such, inside the composite cable 100 (see FIG. 5), signal wires 101 twisted in pairs are often arranged on both sides of two power wires 102.
Note that, although the same applies to each of the figures after FIG. 5, the broken-line circles including the pairs of signal lines 101 represent that the signal lines 101 are twisted in pairs.

However, in this case, when processing the terminal of the composite cable 100, the thickness of the sheath layer 103 is different from the thickness of the signal line 101 (see T1 in the figure) and the power line 102 (see T2 in the figure). Because of the large differences in The end workability of the cable 100 deteriorates.
Therefore, as shown in FIG. 6, for example, if the composite cable 100 is manufactured so that the two power wires 102 are separated from each other, the thickness of the sheath layer 103 is the same as that of the signal wire 101 (see T1 in the figure). and the power line 102 portion (see T2 in the figure) have approximately the same thickness, and the end processability of the composite cable 100 is improved.

However, since the tension applied to the power line 102 during the manufacture of the composite cable 100 is much stronger than the tension applied to the signal line 101, it easily returns to the state shown in FIG. Staying separate isn't always easy. Furthermore, in this state, there is a possibility that the pairs of signal lines 101 may come close to each other or come into contact as shown in FIG. 7 .
Further, in the state shown in FIGS. 6 and 7, the power supply line 102 does not exist between the pairs of signal lines 101.

That is, in the state shown in FIG. 5, the power line 102 exists between the pairs of signal lines 101, so even if noise occurs on one of the pairs of signal lines 101, it is shielded by the power line 102. Therefore, it was not picked up by the other pair of signal lines 101.
However, when the two power supply lines 102 are separated from each other as shown in FIGS. 6 and 7, there is no power supply line 102 between the pair of signal lines 101, so noise may occur on one pair of signal lines 101. If this occurs, it may be picked up by the other pair of signal lines 101, and noise may be added to the signal transmitted via the signal line 101.

The present invention was made in view of the above-mentioned problems, and is a 6-core composite cable comprising two pairs of signal lines and two power lines, which has excellent terminal processability, and also has a pair of signal lines. It is an object of the present invention to provide a composite cable that can accurately shield the cables between the cables.

In order to solve the above problem, the invention according to claim 1,
A composite cable comprising two pairs of signal wires and two power wires having outer diameters different from the signal wires,
Both the signal line and the power line are coated with an insulating coating layer,
The two pairs of signal lines and the two power lines are collectively sheathed with a sheath layer,
A conductive continuum is provided at the center of the composite cable, extending in the longitudinal direction of the composite cable,
The two pairs of signal lines, the two power supply lines, and the continuum are arranged such that the continuum is interposed between each pair of the signal lines, and the continuum is interposed between the two power supply lines. It is characterized by being located.
The above configuration has a structure in which the two pairs of signal lines, the two power supply lines, and the continuum are collectively sheathed with a sheath layer, and the sheath layer is used for the two pairs of signal lines. It may be formed along the outer periphery of the wire and the two power supply wires.

The invention according to claim 2 is the composite cable according to claim 1, which has a structure in which the two pairs of signal wires and the two power supply wires are entirely twisted around the continuum. It is characterized by

The invention according to claim 3 is the composite cable according to claim 1 or 2, wherein the continuous body is composed of a center conductor and an insulating coating layer covering the center conductor. shall be.

According to a fourth aspect of the present invention, in the composite cable according to the third aspect, the center conductor is formed by twisting a plurality of wires together.

The invention according to claim 5 is the composite cable according to claim 3 or 4, wherein each insulating coating layer of the signal line, the power line, and the continuum is coated with a heat-resistant resin. , characterized in that the heat-resistant resin includes a crosslinked resin.

The invention according to claim 6 is the composite cable according to any one of claims 1 to 5, wherein the two pairs of signal wires are twisted together for each pair. Features.

The invention according to claim 7 is the composite cable according to any one of claims 1 to 6, in which the signal line and the power supply line each have a center conductor made of a plurality of twisted wires. It is characterized by being constructed by combining them.

The invention according to claim 8 is the composite cable according to claim 7, wherein the twisted signal wires and the power wires each have a twist ratio of 0.5% or more. It is characterized by

The invention according to claim 9 is the composite cable according to any one of claims 1 to 8, characterized in that the sheath layer is made of a crosslinkable heat-resistant resin.

According to the present invention, in a 6-core composite cable comprising two pairs of signal wires and two power wires, it is possible to have excellent termination processability and to accurately shield between pairs of signal wires. becomes.

FIG. 1 is a cross-sectional view showing the configuration of a composite cable according to the present embodiment. FIG. 3 is a diagram illustrating that the center conductor of a power supply line or a signal line is configured by twisting a plurality of wires together. FIG. 2 is a diagram illustrating a state in which two pairs of signal lines and two power lines are entirely twisted around a continuum in a composite cable. FIG. 7 is a cross-sectional view showing that the sheath thickness of the signal line portion and the power line portion of the composite cable according to the present embodiment is approximately the same. FIG. 2 is a cross-sectional view showing the configuration of a conventional composite cable. FIG. 6 is a cross-sectional view illustrating a state in which two power supply wires are separated from each other in the composite cable of FIG. 5; 7 is a sectional view showing a state in which two pairs of signal lines are in contact with each other in the composite cable of FIG. 6. FIG.

Hereinafter, a composite cable according to the present invention will be explained with reference to the drawings.
However, each embodiment described below has various limitations that are technically preferable for carrying out the present invention, but the scope of the present invention is not limited to the following embodiments or illustrated examples. .

FIG. 1 is a sectional view showing the configuration of a composite cable according to this embodiment.
In this embodiment, the composite cable 1 is a 6-core composite cable including two pairs of signal wires 2 and two power wires 3, each signal wire 2 and each power wire 3 having a central conductor 21, 31 is covered with insulating coating layers 22, 32.
The two pairs of signal wires 2 and the two power wires 3 are directly covered with the sheath layer 4 without any gaps, and the two pairs of signal wires 2 and the two power wires 3 are covered with the sheath layer 4. It has a sheathed structure.

Note that the broken-line circles including the pairs of signal lines 2 in FIG. 1 represent that the signal lines 2 are twisted in pairs.
By configuring the two pairs of signal wires 2 by twisting the signal wires 2 together in each pair in this way, the signal wires 2 can be easily bent in each pair compared to the case where the signal wires 2 are not twisted together. Since the signal line 2 can stretch when the composite cable 1 is pulled in the longitudinal direction, the flexibility and bending resistance (resistance to repeated bending) of the composite cable 1 can be improved.

The signal line 2 may be a central conductor 21 made of a metal wire such as a copper alloy or an aluminum alloy, and coated with an insulating coating layer 22 made of a resin such as polyester.
In addition, although the following explanation is based on the premise that the center conductor 21 of the signal line 2 is a metal wire, the center conductor 21 of the signal line 2 may include, for example, an optical fiber core wire or the like.

The power supply line 3 may be one in which a central conductor 31 made of a conductive wire such as annealed copper, copper alloy, or aluminum is covered with an insulating coating layer 32 made of a resin such as polyester.
Further, the power line 3 used has an outer diameter larger than the outer diameter of the signal line 2. Thus, in this embodiment, the power supply line 3 has a different outer diameter from the signal line 2.

In this embodiment, as shown in FIG. 2, each of the signal line 2 and the power line 3 has a center conductor 21, 31 formed by twisting a plurality of wires 21a, 31a. Note that FIG. 2 does not represent that the center conductor 21 (strand 21a) of the signal line 2 and the center conductor 31 (strand 31a) of the power supply line 3 have the same thickness.
That is, in the signal line 2, the center conductor 21 is formed by twisting together a plurality of wires 21a, that is, a plurality of metal wires. The plurality of wires 21a may be twisted wires that are twisted together as a whole, or may be twisted wires that are made by twisting a plurality of wires and further twisting them together.

In addition, the power supply line 3 is also configured such that the center conductor 31 is composed of a plurality of strands 31a, that is, conducting wires made of annealed copper, copper alloy, aluminum, etc., twisted together.
By configuring it in this way, the signal line 2 itself and the power line 3 themselves are more easily bent than when they are not twisted together, and when the composite cable 1 is pulled in the longitudinal direction, the signal line 2 itself and the power line 3 are easily bent. Since the power supply line 3 itself can be stretched, the flexibility and bending resistance of the composite cable 1 can be improved.

Note that if the twist pitch (the length from one stranded wire arrangement to the next same arrangement) of the strands 21a and 31a that constitute the center conductors 21 and 31 of the signal line 2 and power supply line 3 becomes too small, Compared to the case where the twist pitch is large, the length of the signal line 2 and the power line 3 becomes longer, and the electrical resistance of the signal line 2 and the power line 3 may increase or the signal may decrease.
Therefore, it is desirable that the twist ratios of the twisted signal lines 2 and power lines 3 are set to appropriate values.

Note that the twist rate A (%) is expressed by the following formula (1), where P is the twist pitch and D is the layer core diameter.

According to the research conducted by the present inventors, it has been found that it is preferable that the twist ratio of the signal line 2 and the power line 3 is 0.5% or more.
With this configuration, the flexibility and bending resistance of the composite cable 1 can be improved without unnecessarily increasing the electrical resistance or unnecessarily lowering the signal in the signal line 2 or the power supply line 3. It becomes possible to improve the performance.

On the other hand, in this embodiment, each of the insulating coating layers 22 and 32 of the signal line 2 and the power line 3 is coated with a heat-resistant resin, and the heat-resistant resin is a cross-linked resin such as cross-linked polyethylene. is configured to include.
In this way, by covering each of the insulating coating layers 22 and 32 of the signal line 2 and the power line 3 with a heat-resistant resin, it is possible to improve the heat resistance of the signal line 2 and the power line 3.

By configuring the heat-resistant resin to include a crosslinked resin, it is possible to further improve the heat resistance of the signal line 2 and the power line 3.
Therefore, for example, the composite cable 1 assembled in a vehicle may be exposed to high temperatures due to heat from an engine, etc., but even in such a case, the insulation coating layers 22 and 32 of the signal wire 2 and power wire 3 will melt due to the heat. This makes it possible to prevent damage caused by such things.

In this embodiment, the sheath layer 4 is also made of crosslinkable heat-resistant resin.
As the crosslinkable heat-resistant resin, it is possible to use various resins such as polyolefin resins and polyester resins, which are crosslinked by a crosslinking method such as an electron beam crosslinking method, a chemical crosslinking method, or a silane crosslinking method. The sheath layer 4 can be formed by such methods.

By composing the sheath layer 4 with a crosslinkable heat-resistant resin in this way, the composite cable can be Even if cable 1 is exposed to high temperatures, it is possible to prevent damage to composite cable 1 due to melting of sheath layer 4 due to heat.
Note that it is also possible to configure the sheath layer 4 to be further covered with a resin layer or the like from the outside.

Furthermore, in order to further improve the flexibility and bending resistance of the composite cable 1, the sheath layer 4 may be configured to contain an ethylene-α olefin elastomer, for example.
The ethylene-α olefin elastomer has rubber properties and does not increase in hardness even when exposed to high or low temperatures, so the flexibility and bending resistance of the composite cable 1 are improved regardless of the temperature. Further, there are advantages such as the sheath layer 4 being able to be easily molded.
Further, for the same reason, it is also possible to configure the sheath layer 4 to include a styrene elastomer.

Next, the continuum 5 having electrical conductivity, which is characteristic of the present invention, will be explained.
As shown in FIG. 1, in this embodiment, a conductive continuous body 5 (hereinafter referred to as conductor 5) is provided at the center of the composite cable 1 and extends in the longitudinal direction of the composite cable 1.
Then, two pairs of signal lines 2 and two power lines 3 are connected so that a conductor 5 is interposed between each pair of signal lines 2 and a conductor 5 is interposed between two power lines 3. A conductor 5 is arranged.

The conductor 5 does not transmit a signal like the signal line 2 or supply power like the power line 3, but is a so-called dummy conductor.
For example, a copper wire can be used as the conductor 5, but any continuous body having conductivity may be used, and the conductor 5 does not necessarily need to be a copper wire.

Further, in the conductor 5, the center conductor 51 may be composed of a single continuous body, or may be composed of a plurality of wires twisted together like the signal line 2 and the power supply line 3. . If the conductor 5 has a twisted structure, the flexibility and bending resistance of the composite cable 1 can be improved as in the case of the signal line 2 and the power line 3.
Further, the conductor 5 may be made of a conductive braided wire such as a copper braided wire.

Further, as shown in FIG. 3, for example, the composite cable 1 has a structure in which two pairs of signal lines 2 and two power lines 3 are twisted together around the conductor 5. It is possible to do so.
In this way, the two pairs of signal lines 2 and the two power lines 3 are twisted together as a whole, thereby making it possible to further improve the flexibility and bending resistance of the composite cable 1 as a whole.

On the other hand, in this embodiment, the conductor 5 includes the center conductor 51 as described above and an insulating coating layer 52 covering the center conductor 51.
In this way, if the center conductor 51 of the conductor 5 is covered with the insulating coating layer 52, for example, signals and power flowing through the signal line 2 and the power line 3 are prevented from flowing through the conductor 5. . Therefore, even if the conductor 5 is provided in the composite cable 1, the signal in the signal line 2 and the power supplied by the power line 3 do not deteriorate.

Furthermore, the internal space surrounded by the two pairs of signal lines 2 and the two power lines 3 may not be filled with the sheath layer 4, but if the conductor 5 is not provided, this internal space becomes hollow. However, in this embodiment, this internal space (surrounded by two pairs of signal lines 2 and two power lines 3) Since the conductor 5 is disposed in the internal space (inner space), the conductor 5 prevents water from entering.
Therefore, by providing the conductor 5 (continuous body 5 having conductivity) at the center of the composite cable 1, it is possible to improve the water-stopping property within the composite cable 1.

Furthermore, similarly to the insulating coating layers 22 and 32 of the signal line 2 and the power line 3, the insulating coating layer 52 of the conductor 5 is coated with a heat-resistant resin, and the heat-resistant resin is configured to include crosslinked resin. If so, it becomes possible to improve the heat resistance of the conductor 5.
By configuring the heat-resistant resin to include a crosslinked resin, it is possible to further improve the heat resistance of the conductor 5.

As shown in FIG. 1, in the composite cable 1 according to the present embodiment, a conductor 5 (continuous body 5 having conductivity) is provided at the center of the composite cable 1, extending in the longitudinal direction of the composite cable 1. Two pairs of signal wires 2, two power wires 3, and a conductor 5 are interposed between each pair of signal wires 2, and a conductor 5 is interposed between two power wires 3. is located.
Therefore, as shown in FIG. 4, inside the composite cable 1, the two power wires 3 are separated by the intervening conductor 5, and the power wire 3 is close to the outer surface of the sheath layer 4. It will be placed in the position.

Therefore, as can be seen by comparing the composite cable 1 according to the present embodiment shown in FIG. 4 with the conventional 6-core composite cable 100 shown in FIG. The thickness T2 of the sheath layer 4 is thinner than in the conventional case, and is approximately the same as the thickness T1 of the sheath layer 4 at the pair of signal lines 2.
Therefore, when processing the end of the composite cable 1, the thickness of the sheath layer 4 is different between the signal line 2 portion (see T1 in FIG. 4) and the power line 3 portion (see T2 in FIG. 4). Since the thickness is about the same, the sheath layer 4 is easy to peel off from the signal line 2 part and the power line 3 part, and the sheath layer 4 is easy to peel off, and the signal line 2 part Since there is almost no difference in the thickness of the sheath layer 4 between the part of the signal line 2 and the part of the power line 3, when the sheath layer 4 is peeled off, no sheath layer 4 remains on the part of the signal line 2 or the part of the power line 3. Therefore, in this embodiment, the composite cable 1 has good terminal processability.

Moreover, in the conventional composite cable 100, as shown in FIG. If there is no power line 102 between them (that is, there is no shield) and noise occurs on one pair of signal lines 101, the other pair of signal lines 101 will pick up the noise, and the signal will be There was a possibility that noise would be added to the signal transmitted over the line 101.
On the other hand, in the composite cable 1 according to the present embodiment, as shown in FIG. Even if noise occurs, it is shielded by the conductor 5 (continuous body 5 with conductivity), so the noise is not picked up by the other pair of signal lines 2 and is transmitted through the other signal line 2. No noise is added to the signal.

As described above, according to the composite cable 1 according to the present embodiment, since the conductor 5 (continuous body 5 having conductivity) is extended at the center of the composite cable 1, two pairs of signal lines 2 and two pairs of signal lines 2 and The six-core composite cable 1 including the power supply line 3 has excellent terminal workability, and also enables accurate shielding between pairs of signal lines 2.
The thickness of the conductor 5 is the same as that of the conductor 5 shown in FIGS. It is preferable that the thickness is such that 5 is just the right amount, but it may be a little thicker or a little thinner.

Here, the composite cable 1 according to the present embodiment (Examples 1 to 4), the cables in which the conductor 5 is replaced with a non-conductive one (Comparative Examples 1 and 2), and the conventional composite cable 100 (Fig. 5 See Comparative Example 3), and Table I shows the results of performance evaluation from the viewpoints of terminal workability and shielding properties for the composite cable 100 (Comparative Example 4) having the configuration shown in FIG.

In Table I, "Twisted" indicates whether or not the pair of signal wires 2 and the power supply wire 3 are twisted, and "Yes" indicates that the pair of signal wires 2 and the power supply wire 3 are twisted, and "No" indicates that they are not twisted. Described.
In addition, in the "Structure" column, the numbers of the figures representing the composite cables in the examples and comparative examples are listed.

Furthermore, the "center" column describes the cable extended to the center of the composite cable, and the "electric wire" is the conductor 5 of the composite cable 1 according to the present embodiment, which is constructed by twisting a plurality of wires together. represents something that has been done. "Braid" indicates that the conductor 5 is made of copper braided wire. “Conductor rod” refers to the conductor 5 made up of one continuous body (thin copper rod). "Thread" refers to a thread extending through the center of a composite cable. "Resin rod" refers to a thin plastic rod extending from the center of a composite cable.
Note that a blank column in the "center" column indicates a case where nothing in particular is provided at the center of the composite cable.

In addition, among the evaluation items, "terminal processability" was evaluated by actually peeling off the sheath at the terminal 100 mm of the produced composite cable and evaluating the peelability at that time.
The case where there is no difference in peelability between the signal line part and the power line part of the sheath and there is no remaining peeled sheath on the composite cable is marked as ○, and other cases are marked as ×.

In addition, "shielding property" means that when a predetermined signal is transmitted through each of the two pairs of signal wires of the composite cable that has been fabricated, the signal transmitted through either pair of signal wires will not contain more than a predetermined amount of noise. The case is marked as ○, and the case where it is observed that a predetermined amount or more of noise is added to the signal transmitted through at least one pair of signal lines is marked as ×.

In Examples 1 to 4, good results were obtained in terms of both end workability and shielding properties.
On the other hand, in Comparative Example 1, the continuum (thread) is provided at the center of the composite cable, so the terminal processability is relatively good, but since the continuum is a thread, it is difficult to shield between the pairs of signal lines. The shielding performance is poor.
Similarly, in Comparative Example 2, the continuum (plastic thin rod) is provided at the center of the composite cable, so the terminal processability is relatively good, but since the continuum is a plastic thin rod, , it is not possible to shield between pairs of signal lines, resulting in poor shielding performance.

Comparative Example 3 is a conventional composite cable 100 (see FIG. 5) in which nothing is provided at the center of the composite cable, and two power wires are present between the pairs of signal wires, so the shielding performance is poor. However, when processing the terminal, the peelability is different between the signal line part and the power line part of the sheath, and the sheath is particularly thick at the power line part, so the peelability is poor and it is difficult to peel after stripping. The sheath remains on the power line, resulting in poor terminal processability.
Comparative Example 4 also has poor shielding performance because nothing in particular is provided at the center of the composite cable and pairs of signal lines are in contact with each other (see FIG. 7). In addition, when processing the terminal, the peelability is different between the signal wire part and the power supply wire part of the sheath, and the sheath is particularly thick at the pair of signal wires, so the peelability is poor or the sheath is difficult to peel after stripping. It remains on the power line, resulting in poor terminal processing properties.

It goes without saying that the present invention is not limited to the above-described embodiments, and can be modified as appropriate without departing from the spirit of the present invention.

1 Composite cable 2 Signal line 21 Center conductor 21a Wire 22 Insulating coating layer 3 Power line 31 Center conductor 31a Element wire 32 Insulating coating layer 4 Sheath layer 5 Conductor (continuum with conductivity)
51 Center conductor 52 Insulating coating layer

Claims (9)

A composite cable comprising two pairs of signal wires and two power wires having outer diameters different from the signal wires,
Both the signal line and the power line are coated with an insulating coating layer,
A conductive continuum is provided at the center of the composite cable, extending in the longitudinal direction of the composite cable,
The two pairs of signal lines, the two power supply lines, and the continuum have a structure in which they are collectively sheathed with a sheath layer, and the sheath layer connects the two pairs of signal lines and the two power lines. Formed along the outer circumference of the power line,
The two pairs of signal lines, the two power supply lines, and the continuum are arranged such that the continuum is interposed between each pair of the signal lines, and the continuum is interposed between the two power supply lines. A composite cable characterized by being arranged with. 2. The composite cable according to claim 1, having a structure in which the two pairs of signal lines and the two power lines are entirely twisted around the continuum. 3. The composite cable according to claim 1, wherein the continuous body includes a center conductor and an insulating coating layer covering the center conductor. 4. The composite cable according to claim 3, wherein the center conductor is formed by twisting a plurality of wires together. Each of the insulating coating layers of the signal line, the power supply line, and the continuum is coated with a heat-resistant resin, and the heat-resistant resin includes a crosslinked resin. Composite cable as described in. 6. The composite cable according to claim 1, wherein the two pairs of signal lines are twisted together in each pair. The composite cable according to any one of claims 1 to 6, wherein the signal line and the power supply line each have a center conductor formed by twisting a plurality of wires together. . 8. The composite cable according to claim 7, wherein the twisted signal wires and the power wires each have a twist ratio of 0.5% or more. The composite cable according to any one of claims 1 to 8, wherein the sheath layer is made of a crosslinkable heat-resistant resin.

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