Cable and power supply cable

Abstract

[Problem] To provide a cable and a power supply cable having a new energy stabilizing structure and capable of suppressing the effects of external noise and supplying stable energy and signals. [Solution] This cable comprises: a plurality of conductors each covered with an insulator; a sheath bundling the plurality of conductors; and at least two sets of shielded conductive wire bundles each of which is a bundle of a plurality of conductive wires that have been subjected to insulation coating treatment, the two sets of shielded conductive wire bundles being separately coiled on the outer peripheral surface side of the sheath. At least one of the plurality of conductors is used as a shielded center wire. One end of the shielded conductive wire bundle of a first set is connected to a primary side of the conductor, and the other end of the shielded conductive wire bundle serves as a connection terminal for connection to a secondary-side ground wire. One end of the shielded conductive wire bundle of a second set is connected to the secondary side of the conductor, and the other end of the shielded conductive wire bundle serves as a connection terminal for connection to a primary-side ground wire.

Description

Cables, power cables

[0001] The present invention relates to a cable, a power cable.

[0002] Known cables used for power cables, signal cables, etc. include single-core cables with one conductor (also called core wire) and multi-core cables with two or more conductors. These cables generally consist of a conductor covered with an insulator and a sheath that covers one or more conductors.

[0003] Some cables are equipped with a shield on the inner surface of the sheath that covers the conductor as a countermeasure against external noise. The shield is generally formed by braided strands of copper or aluminum wire, or spiral windings of copper tape.

[0004] For example, in the case of power cables and signal cables for audio equipment, the effects of external noise are particularly noticeable in sound quality. For this reason, efforts are continuing to be made to improve shielding structures that can suppress the effects of external noise and improve sound quality. Of course, this is not limited to cables used in audio equipment; any cable with an internal conductor is susceptible to external noise, so improved shielding structures are also desired in other fields and applications.

[0005] Japanese Patent No. 4282759 Special Publication No. 2013-518360 Japanese Patent Laid-Open No. 2012-33791 Utility Model Registration No. 3238829

[0006] The present invention was made based on these circumstances, and its purpose is to provide a cable, a power cable, that has an unprecedented energy stabilization structure and can suppress the effects of external noise and supply stable energy and signals.

[0007] The gist of the present invention is as follows: (1) A cable of the present invention comprises a plurality of conductors, each coated with an insulator, a sheath bundling the plurality of conductors, and at least two sets of shielding conductor bundles, each a bundle of a plurality of insulating-coated conductor wires, wound as separate coils around the outer circumferential surface of the sheath, wherein at least one of the plurality of conductors is used as a shielding center wire, one end of the shielding conductor bundle of a first set is connected to the primary side of the conductor and the other end of the shielding conductor bundle serves as a connection end for connecting to a ground wire on the secondary side, and one end of the shielding conductor bundle of a second set is connected to the secondary side of the conductor and the other end of the shielding conductor bundle serves as a connection end for connecting to the ground wire on the primary side. (2) The plurality of sets of shielding conductor bundles are braided to form a braided shield covering the outer circumferential surface of the sheath, and any two sets of the shielding conductor bundles are connected to the conductor serving as the shielding center wire. (3) The two sets of shielded conductor bundles are coiled in the same direction from the primary side to the secondary side and do not cross each other. (4) A power cable of the present invention comprises a plurality of conductors each covered with an insulator, a sheath bundling the plurality of conductors, and at least two sets of shielded conductor bundles each consisting of a bundle of a plurality of conductors each covered with an insulating layer and separately coiled around the outer circumferential surface of the sheath, wherein at least one of the plurality of conductors is used as a shield center wire, and one end of the shielded conductor bundle of a first set is connected to the primary side of the conductors and the other end of the shielded conductor bundle is connected to a ground wire on the connector side, and one end of the shielded conductor bundle of a second set is connected to the secondary side of the conductors and the other end of the shielded conductor bundle is connected to a ground wire on the power plug side. (5) The cable of the present invention comprises a conductor coated with an insulator, and at least two sets of shielded conductor bundles, each of which is a bundle of a plurality of insulating coated conductor wires, wound as separate coils around the outer circumferential surface of the conductor, wherein the conductor is used as a shield center wire, and one end of the shielded conductor bundle of a first set is connected to one end of the conductor, and one end of the shielded conductor bundle of a second set is connected to the other end of the conductor.

[0008] According to the present invention, a cable includes at least two sets of shielded conductor bundles, each of which is a bundle of multiple insulating-coated conductor wires, and which are separately coil-wound around the outer circumferential surface of a sheath that binds the multiple conductors. For example, one of the conductors may be used as a shield center wire, and one end of the first set of shielded conductor bundles may be connected to the primary side of the conductor and the other end may be connected to a secondary-side ground wire, while one end of the second set of shielded conductor bundles may be connected to the secondary side of the conductor and the other end may be connected to the primary-side ground wire. This realizes a novel energy stabilization structure that has not been previously available. As a result, it is possible to provide a cable that can supply stable energy and signals while suppressing the effects of external noise.

[0009] Actual tests have confirmed that when this cable is used as a power cable or signal cable for audio equipment, for example, it provides a high level of noise reduction, resulting in an exceptional sense of silence and noiseless, stable sound quality.

[0010] FIG. 1 is an image of a power cable using a cable according to an embodiment of the present invention; FIG. 2 is a cross-sectional view of the cable; FIG. 3 is an image of the internal structure of the cable; FIG. 4 is an enlarged image of the braided shield of the cable; FIG. 5 is an explanatory view of the braided shield of the cable; FIG. 6 is an explanatory view of the braided shield of the cable; FIG. 7 is an explanatory view of the braided shield of the cable; FIG. 8 is an explanatory view of the braided shield of a cable of a comparative example.

[0011] Hereinafter, a cable and a power cable according to preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the technical scope of the present invention should not be construed as being limited by the following embodiments.

[0012] (First embodiment) Fig. 1 shows a power cable 10 for audio equipment using a cable 1 according to the first embodiment. As a preferred example, the cable 1 is a single-phase 100V three-core cable. However, the cable 1 may be a single-core cable or a multi-core cable other than a three-core cable. Furthermore, it is not limited to single-phase 100V. The power cable 10 has a power plug 2 connected to the primary side of the cable 1 and a connector 21 connected to the secondary side. Tests have confirmed that this power cable 10 suppresses the effects of external noise and provides stable sound quality, making it suitable for use with audio equipment. However, there are no limitations on its use, and it can be used as a power cable for supplying power to any device.

[0013] The power plug 2 in FIG. 1 is shown as an example of a grounding-type insertion plug (grounding 2P) having two flat blades 22 and a ground 23, but other types of plugs may be used. For example, a hook-type or a locking-type plug may be used. Furthermore, in addition to the A type commonly used in Japan, any of the B, C, B3, BF, SE, O, and O2 types may be selected, taking into account use overseas. Similarly, the connector 21 may be selected based on the type of device. The connector 21 in FIG. 1 is shown as an example of a 3P female connector (IEC C13).

[0014] 2 and 3, the cable 1 is a circular three-core cable with three conductors 3 arranged therein. The cable 1 includes the three conductors 3, each covered with an insulator 31, a filler 32 as an intermediate sheath, a shield 33, an intermediate sheath 34, a shield 35, an intermediate sheath 36, a braided shield 37, and an overall sheath 38.

[0015] Each conductor 3 is formed of a highly conductive metal such as copper. It may be a twisted wire or a solid wire. The material of the insulator 31 covering each conductor 3 is, for example, heat-resistant PVC. The insulators 31 of each conductor 3 are color-coded, for example, black, white, and red. The three conductors 3 covered with the insulator 31 are bundled so that they are positioned radially from the center of the cable 1 and are held together by the insert 32. In other words, the insert 32 is an example of a sheath that bundles multiple conductors. The material of the insert 32 is, for example, PVC. The three conductors 3 may be bundled in parallel or twisted. Furthermore, although a circular three-core cable is shown as a preferred example, a flat three-core cable in which the three conductors 3 are arranged in a row may also be used.

[0016] The shield 33 serves as a first shield and is disposed between the outer peripheral surface of the interposer 32 and the inner peripheral surface of the intermediate sheath 34. The shield 33 is, for example, a typical spirally wound shield using a metal such as copper wire. The intermediate sheath 34 is made of a material such as PVC. The shield 35 serves as a second shield and is disposed between the outer peripheral surface of the intermediate sheath 34 and the inner peripheral surface of the intermediate sheath 36. For example, the shield is a unidirectionally wound metal sheet such as a magnesium sheet, and is disclosed in detail in Japanese Patent No. 4282759 by the present inventor. The shields 33 and 35 may be of other types. While it is desirable to have both the shield 33 and the shield 35, this is not necessarily required, given the presence of the novel braided shield 37 described below.

[0017] The braided shield 37 serves as a third shield and is provided between the outer peripheral surface of the intermediate sheath 36 and the inner peripheral surface of the overall sheath 38. In other words, the braided shield 37 is disposed on the outer peripheral surface side of the sheath (in this example, the filler 32) that bundles the three conductors together.

[0018] The braided shield 37 is a shield made by braiding multiple conductor wires 4, as shown in FIG. 4 . However, the braided shield 37 of this embodiment differs in configuration from typical braided shields. First, each conductor wire 4 is insulated from the others by an insulating coating. This is a first attempt in the audio industry, preventing resistance and complex resonance. Then, multiple conductor wires 4, each of which is insulated, are braided together (hereinafter referred to as "shielded conductor bundles 41"). As an example, a bundle of 10 conductor wires 4 with an outer diameter of approximately 0.15 mm is braided into 16 sets of shielded conductor bundles 41. The size of the conductor wires 4 and the number of wires in each set may be changed as appropriate. For example, the conductor wires 4 are made of conductive metal wires, such as copper wires, that have been treated with an insulating coating. For example, the insulating coating is preferably a coating of an insulating material, such as a urethane coating. Paint may be applied on top of the conductor wires. Coloring or color-coding can be achieved, for example, by using this painting. Furthermore, the insulating coating process is not limited to a coating of a liquid material, and an insulating material may be coated.

[0019] Second, at least two sets of shielding conductor bundles 41 (41A, 41B) are grounded from among the multiple sets of shielding conductor bundles 41 constituting the braided shield 37. The two sets of shielding conductor bundles 41A, 41B grounded are at least two sets of shielding conductor bundles 41A, 41B wound separately in a predetermined direction. In the example shown in FIG. 4 , these are two sets of three sets of shielding conductor bundles colored black. These two sets of shielding conductor bundles 41A, 41B are wound in parallel coils at a distance from each other in the same direction from the primary side to the secondary side of the cable 1. Clockwise winding as viewed from the primary side is more effective at reducing noise and is therefore more suitable for external noise reduction. Furthermore, parallel winding is more effective at reducing noise and is more suitable for external noise reduction. However, the coils do not necessarily have to be precisely parallel as long as they do not intersect with each other.

[0020] Of the 16 shielded conductor bundles 41, 13 are colored white and 3 are colored black. This enhances the design of the cable 1 and makes it easier to identify the shielded conductor bundles 41A, 41B that are grounded, as shown in Figure 4. Of course, the colors are not limited to white and black. For this reason, the overall sheath 38 is formed of a transparent material. The overall sheath 38 is made of, for example, transparent PVC. Note that images of Figures 1, 3, and 4 were taken without the overall sheath 38.

[0021] Next, with reference to FIG. 5 , the configuration for grounding the two sets of shield conductor bundles 41A, 41B will be described in detail. First, in this embodiment, one of the three conductors 3 (conductor 3C) is used as the "shield center wire." The other conductors 3A, 3B are used for power supply. Conductor 3C, used as the shield center wire, is normally connected to the ground wires 23, 24 of the power plug 2 and connector 21. However, in this embodiment, conductor 3C is used as the "shield center wire" that serves as the energy reference by connecting it as follows: One end (connection end) of the first set of shield conductor bundle 41A is connected to the primary side of conductor 3C. The other end (connection end) of the first set of shield conductor bundle 41A is connected to the ground wire 24 of the connector 21. Finally, one end (connection end) of the second set of shield conductor bundle 41B is connected to the secondary side of conductor 3C. The other end (connection end) of the second set of shielded conductor bundle 41B is connected to the earth wire 23 of the power plug 2. The primary and secondary sides of conductor 3C, which serves as the shield center wire, do not need to be connected to the earth wire 23 of the power plug 2 and the earth wire 24 of the connector 21. This is because connecting them would create an earth loop, which would result in muffled sound in the case of audio equipment.

[0022] Actual tests have confirmed that this configuration provides a high level of noise reduction, resulting in exceptional quietness and noiseless, stable sound quality. Specifically, when a shielded conductor bundle 41 is formed from a bundle of conductors 4 insulated from each other by insulating coating, and two sets of coil-wound shielded conductor bundles 41A, 41B with the same IN and OUT terminals are connected to a single reference energy line (shield center line), and the two sets of coil-wound shielded conductor bundles 41A, 41B are arranged in parallel, an unprecedented energy stabilization structure can be realized, resulting in a high level of noise reduction. The reason for this is believed to be that it facilitates the formation of photons that are not affected by noise and a zero magnetic field.

[0023] The connections of the shield conductor bundles 41A and 41B to the conductor 3C, the earth wire 23 of the power plug 2, and the earth wire 24 of the connector 21 may be reversed.

[0024] Second Embodiment As shown in FIG. 6 , this embodiment is a modified example in which the two sets of shield conductor bundles 41A, 41B connected to ground are replaced with shield conductor bundles 41A, 41C. The remaining configuration is the same as that of the first embodiment, and detailed description thereof will be omitted. As shown in FIG. 6 , the cable 1 of the second embodiment connects two sets of shield conductor bundles 41A, 41C, which are wound in coils in different directions from the primary side to the secondary side of the cable 1, to ground. That is, the first set of shield conductor bundle 41A is wound clockwise as viewed from the primary side, and the second set of shield conductor bundle 41C is wound counterclockwise as viewed from the primary side. Therefore, although there are partial crossovers, the insulating coating of each conductor 4 prevents resistance and complex resonance from occurring.

[0025] In this embodiment, one of the three conductors 3 (conductor 3C) is used as the "shield center wire." One end (connection end) of the first set of shielded conductor bundles 41A is connected to the primary side of conductor 3C. The other end (connection end) of the first set of shielded conductor bundles 41A is connected to the ground wire of the connector 21. One end (connection end) of the second set of shielded conductor bundles 41C is connected to the secondary side of conductor 3C. The other end (connection end) of the second set of shielded conductor bundles 41C is connected to the ground wire of the power plug 2. The primary and secondary sides of conductor 3C, which serves as the shield center wire, do not need to be connected to the ground wire 23 of the power plug 2 and the ground wire 24 of the connector 21. Although the effect of this configuration is smaller than that of the first embodiment, actual tests have confirmed that it provides a higher noise reduction effect than conventional configurations.

[0026] The connections of the shielding conductor bundles 41A and 41C to the conductor 3C, the ground wire 23 of the power plug 2, and the ground wire 24 of the connector 21 may be reversed. Also, instead of the shielding conductor bundle 41A, two sets of shielding conductor bundles 41B and 41C may be connected in the same manner.

[0027] (Third Embodiment) As shown in FIG. 7 , this embodiment is a modified example in which, of multiple sets of right-handed shield conductor bundles 4, one end (connection end) of four sets of shield conductor bundles 4 is connected to the secondary side of the conductor 3C, and the other end (connection end) is connected to the ground wire 23 of the power plug 2. In this case, a high noise-cutting effect is obtained by increasing the area covered on the surface of the cable 1, but work efficiency is poor and there is a slight sense of phase distortion. In contrast, the first embodiment has a simple configuration and achieves the same effect, leading to the conclusion that it is the optimal configuration. In this way, two or more sets of shield conductor bundles 4 may be connected to the shield center wire. The multiple sets are not limited to right-handed sets, and multiple left-handed sets may also be used.

[0028] The connections of the shield conductor bundles 41A and 41B to the conductor 3C, the ground wire 23 of the power plug 2, and the ground wire 24 of the connector 21 may be reversed. Also, as in the second embodiment, two sets of shield conductor bundles 41A and 41C may be connected in the same manner.

[0029] As a comparative example, when one of the three conductors (conductor 3C) was not used as the “shield center wire” as shown in FIG. 8 , that is, when three sets of shielded conductor bundles 41A, 41B, and 41C were connected in series and grounded, only the same noise-cutting effect as a typical braided shield was obtained.

[0030] While the above embodiment has been described using a power cable 10 as an example, it may also be a signal cable. Using the cable 1 achieves an energy stabilization structure and provides a high level of noise reduction. Furthermore, the same effect can be achieved with not only a three-core cable but also a single-core cable or a multi-core cable (e.g., a four-core cable or a three-core x three-core cable). A separate conductor may be used as the shield centerline. In this case, its diameter may be different from that of the other conductors 3. Furthermore, the conductor used as the shield centerline may be located outside the interposer 32. In the example shown in FIG. 2 , for example, a conductor coated with an insulator is placed between the intermediate sheath 34 and the intermediate sheath 36 to form the shield centerline. In this case, the intermediate sheath 36 is an example of a sheath that bundles multiple conductors and has the shield conductor bundle 4 wound around its outer periphery as a coil. While the shield centerline is preferably a single conductor, two or more conductors may be used as the shield centerline.

[0031] Based on the same theory, forming a bracelet, necklace, or the like using the cable 1 can be expected to provide benefits such as improved blood flow. In this case, a single-core cable is used, with the inner conductor serving as the shield center line. One end (connection end) of the first set of shielded conductor bundles 41A is connected to one end of the inner conductor, and one end (connection end) of the second set of shielded conductor bundles 41B is connected to the other end of the inner conductor. The other ends (connection ends) of the first set of shielded conductor bundles 41A and the second set of shielded conductor bundles 41B are in contact with the wearer's skin.

[0032] As described above, the power cable 10 using the cable 1 of this embodiment has a new energy stabilization structure that has never been seen before, and it is possible to provide a cable 1 and a power cable 10 that can suppress the effects of external noise and supply stable energy and signals.

[0033] Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various substitutions, modifications, changes, etc. in form and detail can be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

[0034] REFERENCE SIGNS LIST 1 Cable 10 Power cable 3 Conductor 31 Insulator 32 Interposer 37 Braided shield 4 Insulated conductor 41 Shielded conductor bundle

Claims

1. A cable comprising: a plurality of conductors each coated with an insulator; a sheath for bundling the plurality of conductors; and at least two sets of shielded conductor bundles each being a bundle of a plurality of insulated wires and separately coil-wound on the outer peripheral surface side of the sheath, wherein at least one of the plurality of conductors is used as a shield center line, one end of the first set of the shielded conductor bundles is connected to the primary side of the conductor and the other end thereof is used as a connection end connected to the secondary side ground wire, and one end of the second set of the shielded conductor bundles is connected to the secondary side of the conductor and the other end thereof is used as a connection end connected to the primary side ground wire.

2. The cable according to claim 1, wherein a braided shield is formed by braiding a plurality of sets of the shielded conductor bundles to cover the outer peripheral surface side of the sheath, and any two sets of the shielded conductor bundles are connected to the conductor serving as the shield center line.

3. The cable according to claim 1 or 2, wherein the two sets of shielded conductor bundles are coil-wound in the same direction from the primary side to the secondary side and do not cross each other.

4. A power cable comprising: a plurality of conductors each coated with an insulator; a sheath for bundling the plurality of conductors; and at least two sets of shielded conductor bundles each being a bundle of a plurality of insulated wires and separately coil-wound on the outer peripheral surface side of the sheath, wherein at least one of the plurality of conductors is used as a shield center line, one end of the first set of the shielded conductor bundles is connected to the primary side of the conductor and the other end thereof is connected to the ground wire on the connector side, and one end of the second set of the shielded conductor bundles is connected to the secondary side of the conductor and the other end thereof is connected to the ground wire on the power plug side.

5. A cable comprising: a conductor coated with an insulator; and at least two sets of shielded conductor bundles each being a bundle of a plurality of insulated wires and separately coil-wound on the outer peripheral surface side of the conductor, wherein the conductor is used as a shield center line, one end of the first set of the shielded conductor bundles is connected to one end of the conductor, and one end of the second set of the shielded conductor bundles is connected to the other end of the conductor.

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