JP7426869B2 - composite cable - Google Patents

Description

The present invention relates to a composite cable, and particularly to a composite cable arranged in a vehicle or the like.

Conventionally, in vehicles, ABS cables have been used to transmit signals from ABS sensors placed near the wheels to ABS control devices in order to make the anti-lock brake system (hereinafter referred to as ABS) function. (signal line) is known.
Furthermore, in recent years, with the spread of electric parking brakes (hereinafter referred to as EPB), EPB cables (power lines) that supply power from an EPB control device to an actuator of the EPB are also known.

In a vehicle, the ABS control device and the EPB control device are placed close to each other or at almost the same position, while the ABS sensor and the electric brake actuator are placed on each wheel, so the ABS control device that connects them is Cables and EPB cables are typically installed in a vehicle along similar routes.
Therefore, in the past, these cables were often wrapped together with tape or bundled with cable ties, etc., and then assembled into the vehicle.

On the other hand, in recent years, development of a composite cable in which these cables are combined into one cable has been progressing (see, for example, Patent Document 1).
Also, for example, when a composite cable including the EPB power line, ABS signal line, etc. as described above is placed inside the vehicle, one end of the composite cable may be connected to the tire (brake) part of the vehicle. Because it is attached, the composite cable bends and stretches each time the steering wheel is turned and the tire changes direction, subjecting the composite cable to repeated bending forces.

Therefore, composite cables have high resistance to repeated bending (hereinafter referred to as repeated bending resistance, also referred to as bending resistance, etc.).In other words, even if the composite cable is repeatedly bent, it is difficult for power lines and signal lines to break. is required.
Additionally, in North America, Russia, Scandinavia, and other regions at high altitudes, the temperature can be as cold as -40°C, and composite cables are subjected to repeated bending force in such severe cold, causing power lines to bend. It is also required that wires and signal lines are less prone to breakage, that is, have high repeated flexibility at low temperatures.

Patent Document 2 describes that by manufacturing a composite cable to satisfy predetermined conditions, the composite cable can be made to have excellent repeated bending properties at low temperatures.

Patent No. 5541331 Patent No. 6281662

However, in the research conducted by the inventors, even if a composite cable is manufactured under the conditions described in Patent Document 2, the repeated bendability at room temperature or low temperature may not necessarily be improved depending on the configuration of the composite cable or power line. We found that there is.
As a result of repeated research, we were able to obtain knowledge regarding the structure of composite cables to improve their repeated bendability at room temperature and low temperature.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a composite cable that has excellent repeated bendability not only at room temperature but also at low temperatures.

In order to solve the above problem, the invention according to claim 1,
In a composite cable comprising a plurality of signal lines and a plurality of power supply lines, both of which have a resin layer on the outer periphery of the conductor,
The signal line is thinner than the power line,
Two or more signal lines among the plurality of signal lines are twisted together,
The signal line and the power line are further twisted together,
The occupancy rate of the voids of the conductor in the cross section of the power supply line is 15 to 26%,
The conductor of the power supply line is a twisted rope conductor, and is composed of a wire made of a tin-containing copper alloy with a cross-sectional area of 1.2 to 4.0 mm ² and a tensile strength of 350 to 900 MPa,
The diameter of the strands is 0.05 to 0.2 mm, and the twist ratio of the strands is 1.03 to 1.07.
Further, the composite cable was passed vertically between two mandrels with an outer diameter of 15 mm arranged horizontally and parallel to each other, and one end was passed in an atmosphere of -40°C so as to alternately touch the outer periphery of each mandrel. The wires may be bent at a rate of 60 bends/minute within an angle range of 90 degrees, respectively, and the number of bends before the first breakage occurs is 100,000 times or more.

The invention according to claim 2 is characterized in that, in the composite cable according to claim 1, the plurality of power supply lines include a power supply line for controlling the brake of a vehicle.

The invention according to claim 3 is the composite cable according to claim 1 or 2, wherein the plurality of power lines include a power line that supplies power from a control device of an electric parking brake to an actuator, The plurality of signal lines include a signal line for transmitting a signal from a sensor of the anti-lock brake system to a control device.

According to the present invention, a composite cable including a plurality of power supply lines and a plurality of signal lines has excellent repeated bendability not only at room temperature but also at low temperature.

FIG. 3 is a diagram illustrating a state in which a signal line of a composite cable is connected to an ABS sensor and an ABS control device, and a power line is connected to an EPB control device and an actuator. FIG. 2 is a cross-sectional view showing a configuration example of a composite cable according to the present embodiment, and shows a case of four cores. FIG. 2 is a cross-sectional view showing a configuration example of a composite cable according to the present embodiment, and shows a case of six cores. FIG. 2 is a diagram illustrating that conductors of power supply lines and signal lines are formed by twisting a plurality of wires together. It is a figure showing the state where the signal line and the power line are twisted together in the composite cable as a whole, (a) shows the case of 4 cores, and (b) shows the case of 6 cores. FIG. 3 is a diagram illustrating an internal portion of a resin layer of a power supply line from which a conductor has been removed. FIG. 2 is a schematic diagram of the apparatus used in bending tests 1 to 3, viewed from the axial direction of the mandrel.

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

Note that, although a case will be described below in which a plurality of power lines in the composite cable include a power line for controlling the brake of a vehicle, the present invention is not necessarily limited to this case.
Specifically, in this embodiment, as shown in FIG. 1, the plurality of signal lines 2 of the composite cable 1 include signal lines for transmitting signals from the sensor 11 of the anti-lock brake system to the control device 12. The plurality of power lines 3 include a power line that supplies power from the control device 13 of the electric parking brake to the actuator 14, but is not limited to this case.

2 and 3 are cross-sectional views showing examples of the structure of the composite cable according to the present embodiment, in which the composite cable has four cores, and FIG. 3 shows the case in which there are six cores.
In this embodiment, the composite cable 1 includes a plurality of signal lines 2 and a plurality of power lines 3, and each signal line 2 and each power line 3 are coated with insulating resin on the outer periphery of conductors 21 and 31. It has layers 22 and 32. The plurality of signal lines 2 and the plurality of power supply lines 3 are collectively covered with a sheath layer 4.

Note that the sheath layer 4 may be composed of a plurality of layers.
Furthermore, the composite cable 1 only needs to include a plurality of signal lines 2 and a plurality of power supply lines 3, and is not limited to the four-core or six-core cases shown in FIGS. 2 and 3. Furthermore, although FIG. 2 and FIG. 3 both show the case where two power supply lines 3 are provided, three or more power supply lines 3 may be provided.

Furthermore, the broken-line circles including the pairs of signal lines 2 in FIGS. 2 and 3 represent that the signal lines 2 are twisted together in predetermined units.
In this way, by configuring two or more signal lines 2 out of the plurality of signal lines 2 to be twisted together, the twisted signal lines 2 can be formed more easily than when the signal lines 2 are not twisted together. It becomes flexible.

At the same time, when the composite cable 1 is pulled in the longitudinal direction, the twisted signal wires 2 can stretch in that direction. The wires stretch together, making it difficult for wire breaks to occur.
In this way, by configuring two or more signal lines 2 to be twisted together, it is possible to improve the flexibility and repeated bendability of the composite cable 1.

In this embodiment, the signal line 2 is thinner than the power line 3, like a normal composite cable. The signal line 2 may be a conductor 21 made of a metal wire such as a copper alloy or an aluminum alloy, and coated with an insulating resin layer 22 made of a resin such as polyester.
In addition, although the following explanation is based on the premise that the conductor 21 of the signal line 2 is a metal wire, the conductor 21 of the signal line 2 may include, for example, an optical fiber core wire or the like.

In this embodiment, as shown in FIG. 4, the conductor 21 of the signal line 2 is constructed by twisting together a plurality of metal wires 21a.
Note that FIG. 4 does not represent that the conductor 21 (strand 21a) of the signal line 2 and the conductor 31 (strand 31a) of the power supply line 3 (described later) have the same thickness.

With this configuration, the signal line 2 itself becomes more flexible than when the wires 21a of the signal line 2 are not twisted together.
In addition, when the composite cable 1 is pulled in the longitudinal direction, the signal line 2 itself can stretch in that direction, so if repeated bending force is applied to the composite cable 1, the signal line 2 itself stretches and breaks. etc. are less likely to occur.
In this way, by configuring the conductor 21 of the signal line 2 by twisting a plurality of wires 21a, it is possible to improve the flexibility and repeated bendability of the composite cable 1.

The power supply line 3 has an insulating resin layer 32 around the outer periphery of a conductor 31.
The power supply line 3 is a twisted rope conductor in which the conductor 31 is formed by twisting a plurality of wires 31a together, as shown in FIG. Therefore, as in the case of the signal line 2 described above, the power line 3 itself becomes flexible, and when repeated bending force is applied to the composite cable 1, the power line 3 itself stretches and breaks, etc. Therefore, by configuring the conductor 31 of the power supply line 3 by twisting a plurality of wires 31a, it is possible to improve the flexibility and repeated bendability of the composite cable 1.

Further, the cross-sectional shape of the wire 31a may be circular (round wire) or rectangular (flat wire). Further, the diameter of the wire 31a is 0.05 to 0.2 mm.
Note that the number of strands 31a is not limited as long as it is two or more.
The tensile strength of the wire 31a is preferably 350 to 900 MPa. The tensile strength of the wire can be measured in accordance with JISC 3002.

On the other hand, in this embodiment, as shown in FIG. 5(a), inside the composite cable 1, the twisted signal line 2 and power line 3 are further twisted as a whole.
Therefore, the overall flexibility of the twisted signal line 2 and power line 3 is improved, and when repeated bending force is applied to the composite cable 1, the signal line 2 and power line 3 are stretched as a whole. As a result, disconnections between the signal line 2 and the power supply line 3 are less likely to occur.

Therefore, by further twisting the signal line 2 and the power line 3 as a whole, it is possible to improve the overall flexibility and repeated bendability of the composite cable 1.
Although FIG. 5(a) shows the case where the composite cable 1 has 4 cores (see FIG. 2), the same applies to other configurations. For example, in the case of 6 cores shown in FIG. b)

In the composite cable 1 according to the present embodiment, as described above, the signal line 2 itself and the power line 3 themselves are configured by twisting the strands 21a and 31a (see FIG. 4), or the signal lines 2 are twisted together. (See Figures 2 and 5(a), (b)), and the signal line 2 and power line 3 are twisted together as a whole (see Figures 5(a), (b)). The twisted structure of the power supply wires 3 improves the repeatability of the composite cable 1.

By the way, when comparing the signal line 2 and the power line 3, the effect on the repeated bendability of the composite cable 1 is that the higher repeatable bendability of the thicker power line 3 has a greater effect than the signal line 2. is large.
Further, in the present invention, by twisting the strands 31a of the power source wire 3 as described above, the power source wire 3 itself is configured to repeatedly have flexibility.

However, when the conductors 31 (strands 31a) are densely packed in the resin layer 32 of the power line 3, as in the composite cable described in Patent Document 2 mentioned above, the power line 3 usually becomes hard. This may cause the power line 3 to become difficult to bend, and the repeated bending properties of the power line 3 itself may deteriorate.
As a result of repeated research on this point, the inventors of the present invention found that the power source is It has been found that the flexibility of the composite cable 1 can be improved even when the conductors 31 (strands 31a) are densely packed in the resin layer 32 of the wire 3.

First, the degree of clogging of the strands 31a in the power line 3 can be expressed as the occupancy rate α of the voids of the conductor 31 in the cross section of the power line 3, and the occupancy rate α of the voids can be calculated using the following method. can.
That is, the cross-sectional area of the internal portion A (see the dotted portion in FIG. 6) of the resin layer 32 of the power supply line 3 from which the conductor 31 has been removed is determined using a microscope capable of measuring the area. Note that the area indicated by dots in FIG. 6 represents the internal portion A of the power supply line 3, and does not represent the presence of any object such as a conductor there.

Then, the cross-sectional area of the conductor 31 is calculated based on the configuration of the conductor 31 (the cross-sectional area and number of wires 31a).
and,
α = (Cross-sectional area of internal part - Cross-sectional area of conductor) / (Cross-sectional area of internal part) x 100 [%]
By calculating , it is possible to calculate the occupancy α of the voids of the conductor 31 in the cross section of the power supply line 3 .

If the occupancy rate α of this void is too small (that is, if the conductor 31 is densely packed in the resin layer 32), the power wire 3 becomes hard and difficult to bend, and the power wire 3 itself becomes difficult to bend repeatedly. may be lower.
However, in the research conducted by the present inventors, the cross-sectional area of the conductor 31 of the power line 3 is 1.2 to 4.0 cm ² , and the conductor 31 is a wire made of a tin-containing copper alloy with a tensile strength of 350 to 900 MPa. 31a, and the twisting rate of the wires 31a is configured as follows, the occupation rate α of the voids of the conductor 31 in the cross section of the power supply line 3 can be within the low numerical range of 15 to 26%. It has been found that good repeated bending properties can be obtained in the composite cable 1 even when the composite cable 1 is used.

Here, the twist rate of the strands 31a is determined by cutting out the completed composite cable 1, measuring the length of the cut composite cable 1, and the length of the strands 31a taken out by disassembling the cut composite cable 1, It is defined as the ratio of the length of the taken out strand 31a to the length of the cut out composite cable 1.

If the twisting rate of the wires 31a constituting the conductor 31 of the power supply line 3 becomes too large, the twisting pitch (the length from one stranded wire to the next same arrangement) becomes too narrow, and the stranded wire becomes (The power supply line 3) becomes hard and its flexibility decreases, making it difficult to bend and repeatedly bending it. Further, problems such as an increase in the diameter of the conductor 31 may occur.
Furthermore, if the twisting ratio of the wires 31a becomes too large, the twisting pitch becomes too wide, and the power supply wire 3 becomes close to an untwisted state. The improvement effect will no longer be obtained.

According to the research conducted by the present inventors, it is preferable that the twisting ratio of the strands 31a constituting the conductor 31 of the power supply line 3 is 1.03 to 1.07, and more preferably 1.04 to 1.06. known to be favorable.
In addition, "the twist ratio of the strands 31a is 1.03 to 1.07" means that the length of the strands 31a of the power wire 3 taken out by disassembling the cut out composite cable 1 is longer than the length of the cut out composite cable 1. This means that the length is 3 to 7% longer.

As described above, by designing the twist rate and tensile strength of the strands 31a, the occupation rate α of the voids of the conductor 31 in the cross section of the power wire 3, etc. within the above range, the cross section of the power wire 3 is Even if the void occupancy α of the conductor 31 is within a low numerical range of 15 to 26%, it is possible to reliably improve the flexibility and repeated bendability of the composite cable 1.
Furthermore, it has been found that with this configuration, as shown in the following examples, the composite cable 1 has excellent repeated bendability even in an extremely low temperature environment such as -40°C. It is being

As described above, according to the composite cable 1 according to the present embodiment, the strand 31a of the power supply line 3 is made of a tin-containing copper alloy with a tensile strength of 350 to 900 MPa, and the diameter of the strand 31a is 0.05 to 900 MPa. The conductor 31 of the power supply line 3 is a rope twisted conductor, and the cross-sectional area of the conductor 31 is 1.2 to 4.0 cm. ² , the power line 3 is configured such that the void occupancy rate α of the conductor 31 in the cross section of the power line 3 is 15 to 26%, two or more signal lines 2 which are thinner than the power line 3 are twisted together, The twisted signal line 2 and power line 3 were further twisted together to form a composite cable 1.

Therefore, it becomes possible to improve the repeatability of the composite cable 1 by the twisted structure of the signal wires 2 and the power wires 3.
Further, since the above-mentioned material is used as the wire 31a of the power supply line 3 and the power supply line 3 is configured as described above, the occupation rate α of the void of the conductor 31 in the cross section of the power supply line 3 is 15 as described above. Even if it is as low as ~26%, good repeated bending properties can be obtained in the composite cable 1. The excellent repeated bending properties of the composite cable 1 according to the present embodiment are excellent not only at room temperature but also at low temperatures.

Here, tests conducted regarding repeated bending properties and the like of the composite cable 1 according to the present embodiment (Examples 1 to 4) and composite cables with other configurations (Comparative Examples 1 to 5) will be described.

[Create signal line]
A conductor is made by twisting strands of tin-containing copper alloy wire containing 0.3% Sn and having a diameter of 0.08 mm, and using it and polyethylene (Sumikasen CU5003 (manufactured by Sumitomo Chemical)), an electric wire is made. Extrusion molding was performed so that the outer diameter was 1.4 mm and the resin layer thickness was 0.35 mm, and then, as a crosslinking step, an electron beam of 750 keV and 8 Mrad was irradiated to crosslink the resin layer to obtain a signal line. .

[Create power line]
A conductor was prepared by twisting together wires with a diameter of 0.08 mm made of tin-containing copper alloy wire containing 0.15% Sn or annealed copper (tensile strength is 250 MPa, Comparative Example 5 described later), and polyethylene (Sumikasen). CU5003 (manufactured by Sumitomo Chemical)), extrusion molding was performed so that the outer diameter of the wire was 2.6 mm and the resin layer thickness was 0.45 mm, and then an electron beam of 500 keV and 8 Mrad was applied as a crosslinking process. The resin layer was crosslinked by irradiation to obtain a power line.

[Cable core]
Two of the obtained signal wires were twisted together, and the obtained twisted signal wire and two power supply wires were further twisted together to produce a cable core.
[Creating a composite cable]
Using a material made of flame-retardant crosslinked polyurethane, which is a polyurethane-based resin, the obtained cable core was extruded to form a sheath layer around the cable core so that the outer diameter of the cable was 8.3 mm. Thereafter, as a crosslinking step, the sheath layer was crosslinked by irradiation with an electron beam of 800 keV and 12 Mrad to obtain a composite cable.

Further, the following three types of bending tests were conducted on the composite cable produced as described above.
FIG. 7 is a schematic diagram of the apparatus used in bending tests 1 to 3 below, viewed from the axial direction of the mandrel.

<Bending test 1>
As shown in FIG. 7, the fabricated cable 100 is passed vertically between two mandrels 51 and 52 arranged horizontally and parallel to each other, and between the pressers 61 and 62 for preventing shaking, and the composite cable 100 is A weight (not shown) was attached to the bottom.
In this state, the upper end of the composite cable 100 was bent so as to alternately touch the upper outer periphery of the left and right mandrels 51 or 52 (repeatedly alternately left and right). The number of times of bending was counted as one time when the composite cable 100 was bent so as to be in contact with the outer periphery of either the left or right mandrels 51, 52.

The test conditions were a mandrel diameter of 15 mm, a left and right bending angle of 90°, a bending speed of 60 bends/min, a weight of 500 g, a clearance between the composite cable and the mandrel of 1 mm, and the upper side of the composite cable 100 was The length of the bend was adjusted so that it was in contact with the upper outer periphery, and the test was conducted in an atmosphere at 25°C. The composite cable was connected in series in a loop and energized, and the number of bends until breakage occurred was measured.

The evaluation was based on which of the following criteria the number of times the power supply line or signal line was bent before the first disconnection occurred. "○" and "△" are considered to be passed, and "x" is considered to be failed.
○: 100,000 times or more △: 50,000 times or more, less than 100,000 times ×: Less than 50,000 times

<Bending test 2>
Bending test 2 is a severe test in which the test content is the same as the above-mentioned bending test 1, but the mandrel diameter is 8 mm.
The evaluation was based on which of the following criteria the number of times the power supply line or signal line was bent before the first disconnection occurred. "○" and "△" are considered to be passed, and "x" is considered to be failed.
○: 100,000 times or more △: 50,000 times or more, less than 100,000 times ×: Less than 50,000 times

<Bending test 3>
A bending test was conducted at cryogenic temperatures.
The content of the test was the same as bending tests 1 and 2 above, but the test was conducted in an atmosphere of -40°C.
The evaluation was based on which of the following criteria the number of times the power supply line or signal line was bent before the first disconnection occurred. "○" and "△" are considered to be passed, and "x" is considered to be failed.
○: 100,000 times or more △: 50,000 times or more, less than 100,000 times ×: Less than 50,000 times

Table I below shows the results of performance evaluation regarding the bending resistance of various composite cables produced.
In Table I, the results of the above bending tests 1 to 3 are listed as bending resistances 1 to 3, respectively. Further, "Sn" in the wire material of the power supply line represents a tin-containing copper alloy. Furthermore, in Table I, the presence or absence of twisted power wires, etc. is indicated as "with" or "no", but due to manufacturing constraints of power wires, etc., it is difficult to completely untwist them, so twisting is not possible. The case where no twisting is performed (the case of "none" in Table I) includes the case where the twist is sufficiently small.

In Examples 1 to 4, good results were obtained for all bending resistances 1 to 3. That is, good results were obtained under normal conditions, more severe bending conditions, and extremely low temperature conditions.

On the other hand, in Comparative Example 1, the occupation rate α of the conductor voids in the cross section of the power supply line was 7%. This is a wire with a circular cross section in a close-packed state, but the void occupancy α is too small (that is, the conductor is packed too densely in the resin layer), and none of the bending tests 1 to 3 Even in this case, the power supply line breaks after a relatively small number of bends, resulting in poor repeatability.
In Comparative Examples 2 to 4, either the pair of power wires or signal wires or the entire power wire and signal wire were not twisted; In bending test 3 (cryogenic conditions) and bending test 3 (cryogenic conditions), disconnection occurred in the power supply line and signal line after a relatively small number of bends, resulting in poor repeatability.
Furthermore, in Comparative Example 5, the strands of the power line are made of annealed copper, but when bending force is repeatedly applied to the composite cable, the strands of the power line cannot withstand the tension, and the power line can be bent with a small number of bends. Disconnection occurs in signal wires and signal lines, resulting in poor repeatability.

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.
For example, although FIGS. 2 and 3 show the case where only one sheath layer 4 is formed, it is also possible to form the sheath layer 4 as a plurality of layers.

In addition, since the part inside the vehicle where the composite cable 1 is arranged may become relatively high temperature, the sheath layer 4 (or any one of the plurality of sheath layers 4) of the composite cable 1 and the signal line It is also possible to configure the resin layers 22, 32, etc. of the power line 2 and the power supply line 3 to be formed of heat-resistant resin or the like.

1 Composite cable 2 Signal line 3 Power line 11 Sensor 12 Control device 13 Control device 14 Actuator 21 Conductor 21a Wire 22 Resin layer 31 Conductor 31a Wire 32 Resin layer α Occupancy of void

Claims (3)

In a composite cable comprising a plurality of signal lines and a plurality of power supply lines, both of which have a resin layer on the outer periphery of the conductor,
The signal line is thinner than the power line,
Two or more signal lines among the plurality of signal lines are twisted together,
The signal line and the power line are further twisted together,
The occupancy rate of the voids of the conductor in the cross section of the power supply line is 15 to 26%,
The conductor of the power supply line is a twisted rope conductor, and is composed of a wire made of a tin-containing copper alloy with a cross-sectional area of 1.2 to 4.0 mm ² and a tensile strength of 350 to 900 MPa,
The diameter of the strands is 0.05 to 0.2 mm, the twist rate of the strands is 1.03 to 1.07,
It was passed vertically between two mandrels with an outer diameter of 15 mm arranged horizontally and parallel to each other, and one end was made at an angle of 90° so as to alternately contact the outer periphery of each mandrel in an atmosphere of -40°C. A composite cable characterized in that it can be bent at least 100,000 times before the first breakage occurs when the cable is bent at a speed of 60 bends/min . The composite cable according to claim 1, wherein the plurality of power supply lines include a power supply line for controlling the brake of a vehicle. The plurality of power lines include a power line for supplying power from a control device of an electric parking brake to an actuator, and the plurality of signal lines include a power line for transmitting a signal from a sensor of an anti-lock brake system to a control device. 3. The composite cable according to claim 1, wherein the composite cable includes a signal line.

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