JP2006066135A - Multi-core cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multi-core cable excellent in shielding property, of which connection work at terminals can be easily made. <P>SOLUTION: The multi-core cable is provided with conductors 10 with a plurality of cores, an insulating layer 20 coating the conductors 10 in bundle, a shielding layer 30 provided outside the insulating layer 20, and a sheath 40 provided outside the shielding layer 30. Since the shielding layer 30 can be formed which can coat the conductors with the plurality of cores in bundle, there is no need of carrying out forming of the shielding layer 30 and terminal processing of the cable for each conductor, workability is improved. Further, it is preferable to provide a marking 60 at least on a sheath surface corresponding to a single-core conductor 10 for discriminating the conductor from the others. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a multi-core cable. In particular, the present invention relates to a multi-core cable that is excellent in noise shielding effect and suitable for use at high voltage and large current.

  Conventionally, a cable shown in FIG. 3 is known as a multi-core power cable. This is because three insulated wire cores 20A formed by covering the conductor 10 with the insulator 20 are twisted, the inclusions 70 are fitted into the twisted grooves of the respective insulated wire cores 20A, and the cross section is formed in a circular shape. In this configuration, the sheath 40 is collectively covered.

  In addition, Non-Patent Document 1 discloses a cable in which a shield layer is formed on each insulated wire core in a cable having the same configuration as that in FIG.

  On the other hand, along with the development of electric vehicles and hybrid vehicles, cables for wire harnesses of these vehicles are required to cope with higher voltage and current.

"CV cable" Page 8 Toshiyuki Hayami Corona Co., Ltd. Issued September 1986

  However, the above cable has the following problems.

(1) If there is no shield layer, noise may occur.
If there is no shield layer as in the cable shown in FIG. 3, the generation of noise due to the leakage magnetic field becomes a problem particularly in the case of high voltage applications.

(2) When each insulation core has a shield layer, the shield layer processing at the terminal becomes complicated.
As in the case of the cable described in Non-Patent Document 1, if each insulated wire core has a shield layer, the problem of noise generation can be solved. However, at the end of the cable, the shield layer must be connected to the external shield of the connector. In that case, the terminal processing operation | work which peels a sheath and adjusts the length of the terminal of a shield layer must be performed for every insulated wire core, and processing processing becomes complicated.

(3) When connecting each conductor to the connector, it may be mistaken for another conductor.
The multi-core insulated wire core is not particularly devised for distinguishing each. Therefore, when connecting the conductor of each insulated wire core to the connector at the cable terminal, it is conceivable that the conductor to be connected by mistake is mistakenly connected to another conductor.

(4) In high current applications, the cable is heated by the heat generated by the conductor.
If a high output is to be obtained with a traveling motor such as a hybrid vehicle, the value of the current flowing through the power supply cable inevitably increases, and the heat generated by the conductor increases due to resistance loss. As a result, the cable is heated and reaches the use limit temperature.

  Therefore, a main object of the present invention is to provide a multi-core cable that has excellent shielding properties and can be easily connected at a terminal.

  It is another object of the present invention to provide a multi-core cable that can prevent a plurality of conductors from being mistaken at the time of connection work at a terminal.

  Furthermore, another object of the present invention is to provide a multi-core cable that can suppress the heat generation of the cable and is suitable for large current applications.

  The present invention achieves the above object by forming an insulating layer common to all conductors and forming a shield layer on the insulating layer, instead of individually forming an insulating layer for each of the conductors of a plurality of cores. .

  The multi-core cable of the present invention includes a plurality of conductors, an insulating layer that collectively covers these conductors, a shield layer that is provided outside the insulating layer, and a sheath that is provided outside the shield layer. And

  According to this configuration, instead of providing a shield layer corresponding to each conductor, it is possible to form a shield layer that collectively covers a plurality of conductors, so either during cable manufacture or during cable end processing However, the shield can be formed and the terminal treatment can be performed in a single process. Of course, the provision of the shield layer can avoid the occurrence of noise and the risk of electric shock.

  In the above-mentioned cable, it is preferable that a marking for identifying the conductor from other conductors is provided on the sheath surface corresponding to at least one conductor.

  By providing markings for identifying each conductor on the sheath surface, each conductor can be reliably distinguished, and a connection error to the connector due to a mistake in the conductor can be eliminated.

  Furthermore, in the above cable, it is preferable to have a coolant channel in the insulating layer.

  If a coolant channel is formed in the insulating layer and the coolant is circulated through this channel, the cable can be effectively cooled, and heating of the cable due to heat generated by the conductor can be suppressed. Therefore, the cable can be used for higher current applications.

  Hereinafter, the present invention will be described in more detail.

  The cable of the present invention basically includes a conductor, an insulating layer, a shield layer, and a sheath. If necessary, an internal semiconductive layer may be formed between each conductor and the insulating layer, and an external semiconductive layer may be formed between the insulating layer and the shield layer.

  The conductor is not particularly limited in material and configuration as long as the necessary power transmission capacity can be secured. Examples of the material include copper wire, tin-plated copper wire, aluminum wire, aluminum alloy wire, steel core aluminum wire, copper fly wire, nickel-plated copper wire, silver-plated copper wire, and copper-covered aluminum wire. As the configuration of the conductor of each core, a single wire and a stranded wire are conceivable, but generally a stranded wire structure in which a plurality of strands are twisted is suitable.

  The insulating layer is configured to have a voltage resistance according to the voltage of the cable. Examples of the material of the insulating layer include ethylene propylene rubber, vinyl resin (for example, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, etc.), polystyrene, polyethylene, chlorosulfonated polyethylene rubber, silicon rubber, polytetrafluoroethylene, and the like. . In particular, a cross-linked polyolefin, particularly a cross-linked polyethylene is preferred.

  This insulating layer is typically formed by extrusion. More specifically, the constituent resin of the insulating layer is extruded so as to cover the periphery of each conductor while sending out a plurality of conductors at intervals. This makes it possible to easily form an insulating layer having a circular cross section that collectively covers all conductors with a gap therebetween.

  Further, when forming the refrigerant flow path in the insulating layer, for example, in the manner of extrusion molding of a resin tube, a tubular space is formed inside the insulating layer by applying internal pressure with compressed air from the center of the molding die. Let space be a refrigerant flow path. The position of the refrigerant flow path is preferably formed at a position equidistant from each conductor so that all the conductors can be cooled uniformly. Usually, since each conductor is equally distributed with respect to the center of an insulator, it is preferable to provide the coolant channel at the center of the insulating layer. Any refrigerant may be used as long as it has a cooling effect. For example, air, cooling water, cooling oil, or the like can be used.

  The shield layer covers the conductor via the insulating layer and suppresses the generation of noise due to the leakage magnetic field. Typically, a metal wire braiding material is used. Further, a semiconductive paint may be used for the shield layer. For example, what mixed the binder and the electroconductive filler in the organic solvent is preferable. As the organic solvent, ethyl acetate or toluene can be used. As the binder, acrylic, vinyl, epoxy, alkyd resin, or the like can be used. Examples of the conductive filler include nickel powder and copper powder. In addition, the shield layer may be made of a semiconductive resin. The semiconductive resin used here can use the same material as the inner (external) semiconductive layer described later. In the cable of the present invention, since all the conductors are collectively covered with an insulating layer and a shield layer is provided outside the insulating layer, it is not necessary to form a shield layer or perform terminal treatment for each conductor.

  The sheath is mainly a layer for mechanical protection of the insulating layer (shield layer), and is generally composed of chloroprene rubber, vinyl resin, polyethylene or the like. A marking for identifying the conductor is formed on the surface of the sheath. The marking is preferably provided at a location where a straight line passing through the center of the cable and the center of each conductor intersects the sheath surface. If marking is provided at this position, it can be seen that there is a conductor directly under the marking, and it is possible to more reliably eliminate mistaking each conductor. The marking may be an appropriate mark (character, symbol, figure, etc.) that can distinguish each conductor. If the number of conductors is 3, U, V, W may be used, and if 2 conductors, +,-may be used. As a method for marking the sheath surface, for example, printing by ink transfer, as well as marking on the sheath surface can be used.

  On the other hand, the internal semiconductive layer and the external semiconductive layer suppress the partial discharge at the minute gap existing at the interface between the conductor and the insulating layer or the interface between the insulating layer and the shield layer, thereby suppressing the origin of the water tree. To do. These semiconductive layers are preferably composed of a mixture of a base resin and a conductive filler. Predetermined conductivity can be imparted to the semiconductive layer by mixing conductive fillers. The base resin is preferably polyethylene, polypropylene, polyvinyl chloride, ethylene vinyl acetate, or the like. Carbon black or metal powder can be suitably used as the filler.

  This semiconductive layer can be formed by winding or extruding a conductive cloth tape. In particular, if the semiconductive layer is formed by extrusion, unlike the case where the conductive cloth tape is used, there is no irregular portion such as an end portion or an edge of the conductive cloth tape, and the starting point of the water tree is more effective. Can be eliminated.

  The cable of the present invention is preferably used for high voltage applications. In particular, utilization at 400 V or higher, more preferably 600 V or higher, and even more preferably 1 kV or higher can be expected. As a more specific application, it is preferable to use it for a wire harness of an electric vehicle or a hybrid vehicle. In particular, it is expected to be used as a power supply cable to the motor for traveling and a power cable between the battery and the converter.

  As described above, according to the multicore cable of the present invention, the following effects can be obtained.

  (1) Since a shield layer that covers a plurality of conductors in a lump can be formed in place of each conductor, formation of the shield layer and cable end treatment can be easily performed.

  (2) By forming a marking for identifying each conductor on the surface of the sheath, it is possible to avoid making a wrong connection by connecting the conductor when connecting to the connector.

  (3) By forming the refrigerant flow path in the insulating layer, the refrigerant can be circulated through the flow path, thereby effectively cooling the cable. Therefore, heating of the cable can be suppressed even when using a large current.

  Embodiments of the present invention will be described below.

  FIG. 1 is a cross-sectional view of the cable of the present invention. The cable includes a conductor 10, an insulating layer 20, a shield layer 30, and a sheath 40.

  Here, 19 strands of 0.32 mm diameter annealed copper wire were combined to form a strand, and 19 strands were combined to form a conductor 10 having a nominal cross-sectional area of 30 sq.

  Three conductors 10 are prepared, and an insulating layer 20 is formed to collectively cover these three core conductors. Here, the insulating layer 20 is formed by extrusion, and at that time, the coolant channel 50 is also formed in the center of the insulating layer 20. First, three conductors are supplied to the forming die in a state of being evenly spaced in parallel, and are simultaneously extruded while supplying compressed air from the center of the forming die. By this extrusion, each conductor is arranged in a regular triangle shape in the cross section, a circular coolant channel 50 is formed at the center of this regular triangle, and the cross-sectional outer shape in which all the conductors are collectively covered is a circular insulating layer. 20 is formed. The refrigerant flow path 50 is preferably formed at an equal distance with respect to all the conductors 10. Thereby, any of the conductors 10 can be cooled uniformly. Further, since the insulating layer 20 is interposed between the conductors or between the conductor 10 and the refrigerant flow path 50, the withstand voltage characteristics of the conductors 10 can be sufficiently ensured.

  Next, the shield layer 30 is formed on the insulating layer 20. As the shield layer 30, a braided material made of a tin-plated copper wire having a diameter of 0.3 mm was used. Since each conductor 10 is collectively covered with the insulating layer 20, if the shield layer 30 is formed on the insulating layer 20, all the conductors 10 can be shielded collectively, and noise caused by a leakage magnetic field can be reduced. Occurrence can be suppressed.

  Further, a sheath 40 is formed on the shield layer 30. Here, the sheath 40 was formed by extruding polyvinyl chloride to a thickness of 1.0 mm. A marking 60 is provided on the sheath 40 for identifying each conductor. Here, since there are three-phase conductors 10, each conductor 10 is designated as U, V, W, and the center of the insulating layer 20 (center of the refrigerant flow path) and the straight line passing through the center of each conductor are at the surface position where the sheath intersects. Mark 60. More specifically, as shown in FIG. 2, “U” is repeatedly written in the longitudinal direction of the cable by ink transfer on the surface of the sheath 40. With this marking 60, for example, it can be easily recognized that the conductor immediately below the “U” marking 60 is a U-phase conductor, and can be clearly distinguished from other conductors.

  Although only U-phase marking is shown in FIGS. 1 and 2, in reality, V-phase and W-phase markings are also formed.

  According to the obtained cable, since it is possible to form a shield layer that covers a plurality of conductors at once rather than for each conductor, there is no need to perform shield layer formation and cable end treatment for each conductor, and workability is improved. Can be improved.

  In addition, by forming markings for identifying each conductor on the sheath surface, it is possible to avoid erroneous connection due to mistaken conductors when connecting to the connector.

  Furthermore, if a coolant such as water is circulated through the coolant channel, the cable can be effectively cooled.

  The cable of the present invention can be suitably used as various power supply cables. In particular, it can be suitably used in wire harnesses for electric vehicles, hybrid vehicles, and the like that have recently been required to be used at high voltages and large currents.

It is sectional drawing of this invention multi-core cable. It is an external view of this invention cable. It is sectional drawing of a 3 core lump sheath type conventional cable.

Explanation of symbols

10 Conductor 20 Insulating layer 30 Shield layer 40 Sheath 50 Refrigerant flow path
60 Marking
20A Insulated wire core 70 Inclusion

Claims (3)

Multiple conductors,
An insulating layer that collectively covers these conductors;
A shield layer provided outside the insulating layer;
A multi-core cable comprising a sheath provided outside the shield layer.   The multi-core cable according to claim 1, further comprising a marking on a sheath surface corresponding to at least one conductor to distinguish the conductor from other conductors.   The multi-core cable according to claim 1, wherein the insulating layer has a refrigerant flow path.

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