The present patent application claims the priority of Japanese patent application No. 2020-160461 filed on Sep. 25, 2020, and the entire contents thereof are hereby incorporated by reference.
The present invention relates to a composite cable and a composite harness.
Conventionally, a composite cable in which power lines and signal lines are collectively covered with a sheath is known. A cable known as such a composite cable includes signal lines to be connected to an ABS (Anti-lock Brake System) sensor for measuring the speed of a vehicle's wheel rotation and power lines to be connected to an electric parking brake device for preventing wheel rotation after the vehicle is stopped. (see, e.g., Japanese Patent No. 5541331).
The ABS sensor is attached to an end of an ABS sensor cable. This ABS sensor constitutes a part of an ABS device mounted on the vehicle and is a sensor that measures the speed of the vehicle's wheel rotation. When, e.g., a braking system is activated, the ABS device controls the braking system based on the measured rotation speed of wheels so that the wheels do not spin free.
Patent Document 1: Japanese Patent No. 5541331
The outer diameter of the conventional composite cable becomes large when, e.g., two twisted pair wires and the power lines are twisted together and are covered with a sheath. The conventional composite cable has a problem that resistance to external noise decreases when the twist of the twisted pair wires collapses due to reducing the diameter.
Therefore, it is an object of the invention to provide a composite cable and a composite harness that can be reduced in diameter and can suppress a decrease in resistance to noise.
For solving the above problem, one aspect of the present invention provides a composite cable, comprising:
According to the present invention, it is possible to provide a composite cable and a composite harness that can be reduced in diameter and can suppress a decrease in resistance to noise.
Next, a preferred embodiment according to the present invention will be described with reference to appended drawings, wherein:
(Embodiment)
An embodiment of the invention will be described below in conjunction with the appended drawings.
As shown in
An electric parking brake (EPB) to prevent rotation of the rear wheel 93a and the rear wheel 94a after stopping the vehicle 9 is mounted on the vehicle 9. This electric parking brake includes EPB motors 95, an EPB switch 901 arranged in a vehicle interior, and an EPB control unit 903.
The EPB motors 95 are arranged on the rear wheel 93a and the rear wheel 94a of the vehicle 9. The EPB motors 95 generate a braking force by driving hydraulic braking devices arranged on the rear wheel 93a and the rear wheel 94a. Alternatively, the EPB motors 95 may be arranged on the front wheel 91a and the front wheel 92a or may be arranged on the front wheel 91a to the rear wheel 94a.
The EPB switch 901 is a lever switch and turns from the OFF state to the ON state when the lever is moved up. The EPB switch 901 is electrically connected to the EPB control unit 903.
The EPB control unit 903 is a microcomputer composed of a CPU (Central Processing Unit), a RAM (Random Access Memory) and a ROM (Read Only Memory), etc. The EPB control unit 903 is mounted on an ECU (Electronic Control Unit) 902. Alternatively, the EPB control unit 903 may be mounted on a control unit other than the ECU 902 or may be mounted on a dedicated hardware unit.
The EPB control unit 903 is configured to output a drive current to the EPB motors 95 for a predetermined period of time (e.g., for 1 second) when the EPB switch 901 is turned from the OFF state to the ON state during the stationary state of the vehicle 9 so that a braking force to be applied to the rear wheel 93a and the rear wheel 94a is generated.
The EPB control unit 903 is configured to output a drive current to the EPB motors 95 also when the EPB switch 901 is turned from the ON state to the OFF state or when an accelerator pedal is depressed, so that the braking force on the rear wheel 93a and the rear wheel 94a is released. The EPB switch 901 is not limited to the lever switch and may be a pedal switch.
An anti-lock braking system is also mounted on the vehicle 9. This anti-lock braking system includes ABS sensors 65 arranged for the front wheel 91a to the rear wheel 94a, and an ABS control unit 904.
The ABS sensors 65 are arranged for the front wheel 91a to the rear wheel 94a and detect the rotation speeds of the front wheel 91a to the rear wheel 94a. The ABS sensors 65 are electrically connected to the ABS control unit 904.
As shown in
As shown in
As described later, the ABS control unit 904 calculates the rotation speed based on signals output from the plural sensors and also detects failure of the ABS sensors 65.
The ABS control unit 904 is a microcomputer composed of a CPU, a RAM and a ROM, etc. The ABS control unit 904 is mounted on the ECU 902. The ABS control unit 904 controls the braking force to the front wheel 91a to the rear wheel 94a based on outputs from the ABS sensors 65 so that the front wheel 91a to the rear wheel 94a do not lock at the time of emergency stop. Alternatively, the ABS control unit 904 may be mounted on a control unit other than the ECU 902 or may be mounted on a dedicated hardware unit.
One end of a composite harness 1 in the present embodiment is electrically connected to the EPB motor 95 located outside the vehicle body 90 and is also electrically connected to the sensor head 6 that houses the ABS sensor 65. Meanwhile, the other end of the composite harness 1 is electrically connected to a wire group 99b in a rear wheel-side junction box (relay box) 97b inside the vehicle body 90 and is electrically connected to the ECU 902.
The ABS sensors 65 arranged for the front wheel 91a and the front wheel 92a are electrically connected to the ECU 902 via front wheel-side junction boxes 97a and wire groups 99a.
The ECU 902 is electrically connected to a battery 900. The EPB control unit 903 of the ECU 902, when activating the electric parking brake, generates a drive current from the battery 900 and supplies it to the EPB motors 95 via the wire groups 99b, the junction boxes 97b and the composite harnesses 1. Meanwhile, the ABS control unit 904 generates power-supply voltage Vcc from the battery 900 and supplies it to the sensor heads 6 via the wire groups 99b, the junction boxes 97b and the composite harnesses 1.
(Configuration of the Composite Harness 1)
As shown in
As shown in
The signal line unit 30 includes plural pairs of signal line 3 and an inner sheath 35 covering a first assembled article 11 that is formed by arranging the signal lines 3 to be paired at each pair of opposing vertices of a polygon with an even number of vertices in a cross-section perpendicular to a longitudinal direction of the signal line unit 30 and twisting all signal lines 3 together. In the composite cable 10, a binding tape 4 is provided between the second assembled article 12 and the outer sheath 5.
The two power lines 2 are used as a pair and thus will be referred to as a pair of power lines 2. However, the number of the power lines 2 is not limited thereto and may be more than two.
The four signal lines 3 will be referred to as a signal line 3a, a signal line 3b, a signal line 3c and a signal line 3d from the top left in the clockwise direction on the paper surface of
(Configuration of the Power Line 2)
The pair of power lines 2 are used to supply a drive current to the EPB motor 95. The vehicle external-side EPB connector 23 to be connected to the EPB motor 95 is attached to one end of the pair of power lines 2, and the vehicle internal-side EPB connector 24 to be connected to the junction box 97b in the vehicle is attached to the other end of the pair of power lines 2.
As shown in
Strands having a diameter of 0.05 mm or more and 0.30 mm or less can be used to form the first conductor wire 21, as an example. When using strands having a diameter of less than 0.05 mm, sufficient mechanical strength may not be obtained, causing a decrease in flex resistance. On the other hand, when using strands having a diameter of more than 0.30 mm, flexibility of the composite harness 1 may decrease. An outer diameter of the power line 2 is 3.0 mm, as an example.
(Configuration of the Signal Line 3)
The four signal lines 3 are covered with the inner sheath 35 in a state where adjacent ones of the signal lines 3 are in contact with each other. The four signal lines 3 in contact with each other are twisted together and a hollow is formed at the center, as shown in
The sensor head 6 housing the ABS sensor 65 is attached to one end of the signal line unit 30 and the vehicle internal-side ABS connector 64 to be connected to the junction box 97b in the vehicle is attached to the other end of the signal line unit 30.
The signal line 3 is composed of a second conductor wire 31 and a second insulation 32 covering the second conductor wire 31. The second conductor wire 31 is formed by, e.g., twisting plural strands composed of copper or a coper alloy. The second insulation 32 is formed using, e.g., cross-linked polyethylene.
Strands having a diameter of 0.05 mm or more and 0.30 mm or less can be used to form the second conductor wire 31, in the same manner as the first conductor wire 21. An outer diameter of the signal line 3 is 1.35 mm, as an example. An outer diameter of the inner sheath 35 in a state of covering the four signal lines 3 is 4.5 mm, as an example. A twisting direction of the second conductor wire 31 may be either clockwise or counterclockwise on the paper surface of
The inner sheath 35 is provided to protect the four signal lines 3 and also to allow the shape to be easily adjusted when twisted with the pair of power lines 2. The inner sheath 35 is formed by, e.g., extruding a resin such as polyurethane.
The four signal lines 3 as the first assembled article 11 are all twisted together. A twist pitch of the first assembled article 11 is about 40 mm, as an example. A twisting direction of the first assembled article 11 will be described later. Meanwhile, the pair of power lines 2 and the signal line unit 30 are all twisted together and form the assembled article 12. A twist pitch of the second assembled article 12 is about 60 mm, as an example. A twisting direction of the second assembled article 12 will be described later.
A cross-sectional area (a conductor cross-sectional area) of the first conductor wire 21 and a thickness of the first insulation 22 in the power line 2 are appropriately adjusted according to magnitude of required drive current. In the present embodiment, the cross-sectional area (the conductor cross-sectional area) of the first conductor wire 21 is set to be larger than that of the second conductor wire 31 of the signal line 3, as described above. In other words, the first conductor wire 21 is formed thicker than the second conductor wire 31.
(Arrangement of the Signal Lines 3)
As shown in
The vertex 80 and the vertex 82 are located opposite to each other. Thus, the signal line 3a is arranged so as to correspond to the vertex 80 and the signal line 3c paired with the signal line 3a is arranged so as to correspond to the vertex 82, as shown in
The vertex 81 and the vertex 83 are located opposite to each other. Thus, the signal line 3b is arranged so as to correspond to the vertex 81 and the signal line 3d paired with the signal line 3b is arranged so as to correspond to the vertex 83, as shown in
Here, a magnetic field 30a and a magnetic field 30c formed by the paired signal lines 3a and 3c repel each other at the center between the signal line 3a and the signal line 3c and have a shape drawn outward as shown in
Likewise, a magnetic field 30b and a magnetic field 30d formed by the paired signal lines 3b and 3d repel each other at the center between the signal line 3b and the signal line 3d and have a shape drawn outward as shown in
As such, by arranging the paired signal lines 3 so as to be located oppositely as shown in
As a modification, the signal lines 3 may be arranged in such a manner that each pair is arranged at a pair of opposing vertices of the polygon 8 with six vertices, as shown in
In this modification, as an example, the signal line 3a arranged at the vertex 80 is paired with the signal line 3d arranged at the vertex 83, the signal line 3b arranged at the vertex 81 is paired with the signal line 3e arranged at the vertex 84, and the signal line 3c arranged at the vertex 82 is paired with the signal line 3f arranged at the vertex 85.
Alternatively, the signal lines 3 may be arranged in such a manner that each pair is arranged at a pair of opposing vertices of a polygon with a different even number of vertices.
(Twisting Directions)
The twisting direction of the first assembled article 11 is a direction that, when viewed from one end of the first assembled article 11, the signal lines 3 rotate from the other end to the one end. The twisting direction of the second assembled article 12 is a direction that, when viewed from one end of the second assembled article 12, the pair of power lines 2 and the signal line unit 30 rotate from the other end to the one end.
In particular, the composite cable 10 is configured such that when the twisting direction of the first assembled article 11 is counterclockwise (rotating left) on the paper surface of
The composite cable 10 is also configured such that the twisting direction of the first conductor wire 21 of the power line 2 is opposite to the twisting direction of the first assembled article 11 and is the same as the twisting direction of the second assembled article 12.
The twisting direction of the first assembled article 11 and the twisting direction of the second assembled article 12 are opposite to each other on the following grounds:
Meanwhile, the reason why the twisting direction of the second assembled article 12 and the twisting direction of the first conductor wire 21 are the same is to suppress looseness of the twist of the first conductor wire 21.
(Configuration of the Binding Tape 4)
The binding tape 4 is spirally wound around the second assembled article 12. The binding tape 4 is interposed between the second assembled article 12 and the outer sheath 5 and is used to reduce friction between the second assembled article 12 and the outer sheath 5 when being bent, to improve handling properties of the composite cable 10 and to make the cross-sectional shape close to a circle.
The composite cable 10 may additionally have interpositions between the binding tape 4 and the power lines 2/the signal line unit 30. The interposition is a filler placed to fill between the binding tape 4 and the power lines 2/the signal line unit 30 and is formed in a string shape using an insulating material. The interposition is, e.g., cotton yarn composed of cotton, paper string, or string of synthetic fibers such as polypropylene.
The binding tape 4 is spirally wound around the second assembled article 12 in a state where a tensile force is applied. Thus, it is necessary to use the binding tape 4 which is not broken by a tensile force applied during winding. Meanwhile, the binding tape 4 is removed together with the outer sheath 5 when the cable is terminated. Therefore, it is desirable to use the binding tape 4 which can be easily removed at the time of cable termination.
Therefore, it is possible to use the binding tape 4 which is composed of, e.g., non-woven fabric, paper such as Japanese paper, or resin (resin film, etc.).
(Configuration of the Outer Sheath 5)
The outer sheath 5 covers and protects the pair of power lines 2 and the signal line unit 30 around which the binding tape 4 is wound. The outer sheath 5 is formed by, e.g., extruding a resin such as polyurethane around the binding tape 4.
(Configuration of the Sensor Head 6)
The sensor head 6 is formed by, e.g., injection molding using a thermosetting resin such as PC (Polycarbonate) or ABS (Acrylonitrile Butadiene Styrene).
As shown in
The sensor holder 60 has an elongated quadrangular prism shape and has a base portion 60a and a tip portion 60b. The base portion 60a protrudes from a front surface 61a of the flange 61. The tip portion 60b is a tip portion of the base portion 60a, has a more elongated shape than the base portion 60a, and houses the ABS sensor 65.
The flange 61 has a plate shape. The sensor holder 60 is provided on the front surface 61a of the flange 61 and the cable holder 62 is provided on a back surface 61b of the flange 61. The flange 61 also has a through-hole 63 through which a bolt is inserted when attaching to the vehicle 9. Alternatively, a metal reinforcing member may be inserted through the through-hole 63.
The cable holder 62 holds the signal line unit 30. The signal line unit 30 and the ABS sensor 65 are integrated with the sensor head 6 by injection molding.
(Configuration of the ABS Sensor 65)
The ABS sensor 65 has the first sensor IC 65a and the second sensor IC 65b for the purpose of redundancy. Each of the first sensor IC 65a and the second sensor IC 65b is configured to, e.g., detect a change in magnetic fields formed by the first magnetized regions 71 and the second magnetized regions 72 due to rotation of the rotor 7, output a detection signal indicating “Hi” when the change is detected, and output a detection signal indicating “Lo” when the change is not detected.
The first sensor IC 65a has a control unit 650a, a magnetic sensor 651a, an input terminal 652a and an output terminal 653a. The control unit 650a, the magnetic sensor 651a and end portions of the input terminal 652a and the output terminal 653a are sealed with a sealing resin.
As an example, the control unit 650a has a predetermined threshold and outputs a detection signal Si indicating “Hi” when an output of the magnetic sensor 651a is not less than the threshold. This detection signal S1 is a square wave consisting of “Hi” and “Lo”.
The magnetic sensor 651a has four magnetoresistive elements that form a bridge circuit. These four magnetoresistive elements are arranged with angles differed by 90° in a plane indicated by a dotted line in
The magnetic sensor 651a and the magnetic sensor 651b (to be described later) here are not limited to the magnetoresistive elements and may be configured using magnetic sensor elements that detect a change in magnetic field, such as GMR (Giant MagnetoResistive effect) elements or Hall elements. Meanwhile, the first sensor IC 65a and the second sensor IC 65b may be configured to include bias magnets that cause a bias magnetic field to act on the magnetic sensor 651a and the magnetic sensor 651b. In this case, the rotor 7 does not need to be magnetized, is formed of a magnetic material and has plural gear teeth formed at equal intervals in a circumferential direction. The sensor head 6 is arranged so as to face the gear teeth, and the magnetic sensor 651a and the magnetic sensor 651b detect a change in the bias magnetic field caused by approach of the gear teeth.
The input terminal 652a and the output terminal 653a are composed of, e.g., an alloy of copper or aluminum, etc., and are formed in an elongated plate shape. The input terminal 652a and the output terminal 653a are electrically connected to the control unit 650a. The input terminal 652a and the output terminal 653a may be configured as part of a lead frame on which electronic components such as the control unit 650a are arranged.
The first signal line pair 33, which is a pair of signal lines 3, is connected to the input terminal 652a and the output terminal 653a. In particular, as shown in
The power-supply voltage Vcc to drive the first sensor IC 65a is supplied to the input terminal 652a from the ABS control unit 904. The output terminal 653a is connected to a ground circuit (GND) and the detection signal S1 is output to the ABS control unit 904 through the output terminal 653a.
The second sensor IC 65b has a control unit 650b, the magnetic sensor 651b, an input terminal 652b and an output terminal 653b. The control unit 650b, the magnetic sensor 651b and end portions of the input terminal 652b and the output terminal 653b are sealed with a sealing resin.
The control unit 650b has a predetermined threshold and outputs a detection signal S2 indicating “Hi” when an output of the magnetic sensor 651b is not less than the threshold. This detection signal S2 is a square wave consisting of “Hi” and “Lo”.
The magnetic sensor 651b has four magnetoresistive elements that form a bridge circuit, in the same manner as the magnetic sensor 651a. Since the magnetic sensor 651b and the magnetic sensor 651a are arranged in parallel, the magnetic sensor 651b is parallel to the surface 70 of the rotor 7.
The input terminal 652b and the output terminal 653b are composed of, e.g., an alloy of copper or aluminum, etc., and are formed in an elongated plate shape. The input terminal 652b and the output terminal 653b are electrically connected to the control unit 650b. The input terminal 652b and the output terminal 653b may be configured as part of a lead frame on which electronic components such as the control unit 650b are arranged.
The second signal line pair 34, which is a pair of signal lines 3, is connected to the input terminal 652b and the output terminal 653b. In particular, as shown in
The power-supply voltage Vcc to drive the second sensor IC 65b is supplied to the input terminal 652b from the ABS control unit 904. The output terminal 653b is connected to the ground circuit (GND) and the detection signal S2 is output to the ABS control unit 904 through the output terminal 653b.
Since the second conductor wires 31 are connected to the first sensor IC 65a on the front side and to the second sensor IC 65b on the opposite back side as shown in
The first sensor IC 65a and the second sensor IC 65b are closely arranged and thus detect a change in magnetic field due to rotation of the rotor 7 in the same way. Therefore, the detection signal S1 output from the first sensor IC 65a and the detection signal S2 output from the second sensor IC 65b have substantially the same waveform and reliability is further improved.
The ABS control unit 904 calculates a rotation speed of the rotor 7 from, e.g., timing of “Hi” and “Lo” of any one of the detection signal S1 and the detection signal S2. Alternatively, the ABS control unit 904 may use an average of the rotation speed calculated from the detection signal S1 and the rotation speed calculated from the detection signal S2 as the rotation speed of the rotor 7.
The ABS control unit 904 also can perform failure detection by using the detection signal S1 and the detection signal S2. For example, in case that only the first sensor IC 65a is arranged and this first sensor IC 65a fails and keeps outputting the detection signal S1 indicating “Lo”, the ABS control unit 904 cannot detect whether the rotor 7 is not rotating, i.e., the vehicle is stationary or the first sensor IC 65a is failing to operate properly, only by the detection signal S1.
However, in case that the first sensor IC 65a and the second sensor IC 65b are arranged, the ABS control unit 904 compares the detection signal S1 to the detection signal S2 and thereby can determine that one of the first sensor IC 65a and the second sensor IC 65b is failing to operate properly. When failure is detected, the ABS control unit 904 outputs a signal indicating occurrence of failure to the ECU 902 and causes a display device of the vehicle 9 to display an alert indicating failure.
(Functions and Effects of the Embodiment)
As described above, in the composite harness 1 of the present embodiment, plural pairs of signal line 3 are arranged at opposing vertices of a polygon and are twisted together while maintaining a state of being in contact with each other. Therefore, as compared to when such a configuration is not adopted, it is possible to reduce the diameter of the signal line unit 30 and also suppress a decrease in resistance to noise.
In the composite harness 1, kink of the first assembled article 11 and kink of the second assembled article 12, which are caused by twisting, are in the opposite directions and thus cancel out each other, allowing the composite cable 10 to be straight with suppressed kink.
In the composite harness 1, the twisting directions of the first assembled article 11 and the second assembled article 12 are different. Therefore, as compared to when twisted in the same direction, it is possible to maintain the twist pitch of the first assembled article 11 and thereby possible to suppress an effect of external noise due to unstable twist. In addition, since the composite harness 1 can suppress the effect of external noise, it is possible to highly accurately calculate the rotation speed based on the detection signal S1 output from the first magnetic sensor 651a of the first sensor IC 65a and the detection signal S2 output from the second magnetic sensor 651b of the second sensor IC 65b and it is also possible to highly accurately detect failure, hence, it is possible to improve reliability.
In the composite harness 1, the twisting directions of the first assembled article 11 and the second assembled article 12 are different. Therefore, as compared to when twisted in the same direction, it is possible to suppress looseness of the twist of the first assembled article 11.
In the composite harness 1, the twisting direction of the first conductor wire 21 of the power line 2 and the twisting direction of the second assembled article 12 are the same. Therefore, as compared to when twisted in different directions, it is possible to suppress looseness of the twist of the first conductor wire 21.
(Summary of the Embodiment)
Technical ideas understood from the embodiment will be described below citing the reference numerals, etc., used for the embodiment. However, each reference numeral, etc., described below is not intended to limit the constituent elements in the claims to the members, etc., specifically described in the embodiment.
[1] A composite cable (10), comprising: a plurality of power lines (2); one signal line unit (30); and a sheath (5) collectively covering the plurality of power lines (2) and the one signal line unit (30), wherein the signal line unit (30) comprises a plurality of pairs of signal lines (3), and an inner sheath (35) covering a first assembled article (11) including the signal lines (3) to be paired being arranged at a pair of opposing vertices (80 and 82, 81 and 83) of a polygon (8) with an even number of vertices (80 to 83) in a cross-section perpendicular to a longitudinal direction of the signal line unit (30) and being twisted all together.
[2] The composite cable (10) described in [1], wherein the sheath (5) is provided so as to collectively cover a second assembled article (12) including the plurality of power lines (2) and the one signal line unit (30) being twisted together.
[3] The composite cable (10) described in [2], wherein a twisting direction of the first assembled article (11) is different from a twisting direction of the second assembled article (12).
[4] The composite cable (10) described in any one of [1] to [3], wherein the plurality of pairs of signal lines (3) are twisted together in a state where adjacent ones of the signal lines (3) are in contact with each other.
[5] A composite harness (1), comprising: the composite cable (10) described in any one of [1] to [4]; and a connector (23, 24, 64) attached to at least any of end portions of the plurality of power lines (2) and the signal line unit (30).
Although the embodiment of the invention has been described, the invention according to claims is not to be limited to the embodiment described above. Further, please note that not all combinations of the features described in the embodiment are necessary to solve the problem of the invention.
The invention can be appropriately modified and implemented without departing from the gist thereof.
The composite cable 10 of the composite harness 1 in the present embodiment has plural insulated wires 13 that are arranged between the power lines 2/the signal line unit 30 and the binding tape 4, e.g., as shown in
In addition, although the ABS sensor 65 in the embodiment uses the first sensor IC 65a and the second sensor IC 65b to detect failure, it is not limited thereto. One of the sensor ICs may be mainly used and the other sensor IC may be used as a backup. In this case, as an example, the ABS control unit 904 performs failure detection based on information about the vehicle 9 acquired from the ECU 902 and a detection signal acquired from the main sensor IC, and switches to the backup sensor IC based on occurrence of failure.
Number | Date | Country | Kind |
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2020-160461 | Sep 2020 | JP | national |