JP2008004328A - Receptacle plug, and power-line carrier communication apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a receptacle plug and a power line communication device from an adverse effect on electric characteristics due to expansion and contraction of resin even in case partitioning core members are used, or further, from an adverse effect on electric characteristics due to capacity constituents of resin. <P>SOLUTION: A pair of plug terminals 7 capable of being plugged into a pair of plug receptacles of the power line, a pair of signal wires 8 with one end connected to the pair of plug terminals 7 and the other end connected to an AC cable of an electronic equipment, a magnetic material core 9 with an end each of a pair of partitioning core members face the other in a circular shape and with the pair of signal wires 8 wound around in a bifilar winding, and sealing resin 12 covering and housing inside the signal wires 8 and the magnetic material core 9. An air layer AR is formed in at least an inside area of the magnetic material core 9 out of peripheral areas of the same. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an outlet plug of an AC cable used for an electronic device such as a power line communication device and a power line communication device including the same, which have a noise filter function and a leakage electromagnetic field suppression function.

  2. Description of the Related Art Conventionally, some AC cables used in electronic devices are provided with a noise filter (line filter) in an outlet plug in order to supply power from which noise components have been removed to the device. For example, Patent Document 1 proposes an insertion plug in which a synthetic resin is filled in an insulating case that houses a noise filter element. A choke coil is used as the noise filter element.

  On the other hand, in recent years, power line communication (PLC) for performing data communication between communication devices via a power line wired in a building such as a general house has been studied. In this power line communication, there is a problem of a leakage electromagnetic field in which radio waves leak indoors from the power line during communication, and it is known that a leakage electromagnetic field is generated particularly when a common mode current is generated in the line. In the circuit for reducing the common mode current, a common mode choke coil or the like in which a signal line is wound around a toroidal coil is used.

Japanese Utility Model Publication No. 7-44052

The following problems remain in the conventional technology.
Conventionally, as a noise filter element, a common mode choke coil in which a signal line is wound around a toroidal core is often used. However, the process of winding a signal line around a ring-shaped core is expensive and reduces manufacturing costs. In addition, a pair of split core members obtained by splitting the toroidal core into two may be employed. That is, a closed magnetic circuit similar to that of the toroidal core is configured by passing through a pair of split core members divided into two in which a signal line is wound around a bobbin and bringing the ends into contact with each other. However, in the technique of Patent Document 1, the noise filter element is filled with a synthetic resin. However, if the noise filter element using the divided core member is similarly sealed with the synthetic resin, the process of synthesizing the synthetic resin is performed. There is a possibility that the contact state of the split core member changes due to the expansion and contraction due to the expansion and contraction due to the temperature change after molding, which affects the electrical characteristics. Moreover, the coupling | bonding by the electrostatic capacitance component which the synthetic resin to fill has had produced, and this had a possibility of affecting an electrical property.
Further, in the power line communication, the use of a line filter circuit using a common mode choke coil or the like is being studied for suppressing the leakage electromagnetic field. However, in order to obtain the same configuration as the toroidal core at a low cost, It has been studied to use the divided core member.

  The present invention has been made in view of the above-mentioned problems, and even if a split core member is used, the influence on the electric characteristics due to the expansion and contraction of the resin is prevented, and further the influence of the electric characteristics due to the capacitive component of the resin is suppressed. It is an object of the present invention to provide an outlet plug that can be used and a power line communication device including the same.

  The present invention employs the following configuration in order to solve the above problems. That is, the outlet plug of the present invention includes a pair of plug terminals that can be plugged into a pair of outlet jacks of a power line, and a pair of signals that have one end connected to the pair of plug terminals and the other end connected to an AC cable of an electronic device. A magnetic core in which a pair of the signal lines are wound by bifilar winding or cancellation winding, and the signal line and the magnetic core; And an encapsulating resin that is housed inside, and an air layer is formed in at least an inner region of the magnetic core in a peripheral region of the magnetic core.

  In this outlet plug, since an air layer is formed at least in the inner region of the magnetic core in the peripheral region of the magnetic core, even if expansion and contraction occurs due to the solidification process of the sealing resin and temperature change after molding, Since stress is applied from the sealing resin on the outer side of the magnetic core toward the inner air layer, a force acts in the direction in which both ends of the pair of split core members are abutted. For this reason, the contact state of a pair of division | segmentation core member is hold | maintained reliably, and a favorable electrical property is maintained. In addition, since the periphery of the magnetic core (especially the inner region) is an air layer, the entire dielectric constant can be reduced compared to the case where all of the sealing resin is filled, and the capacitance is reduced. Suitable for high frequency communication.

  The outlet plug of the present invention is characterized in that the air layer is formed of a foamed resin. That is, in this outlet plug, since the air layer is formed of the foamed resin, the air layer can be obtained in a state where a large amount of air is held in the pores of the porous foamed resin, and the sealing resin An air layer region can be secured at the time of molding.

  In addition, the outlet plug of the present invention includes a case that hermetically accommodates the magnetic core, and the sealing resin seals the magnetic core together with the case, and the air layer is formed in the case. It is characterized by. That is, in this outlet plug, since an air layer is formed in the case that houses the magnetic core, the air layer is secured by the case and the expansion stress of the sealing resin can be supported by the strength of the case itself.

A power line communication apparatus according to the present invention is a power line communication apparatus that performs data communication via a power line, and includes an apparatus main body having a function of transmitting and receiving by power line communication, and an AC cable connected to the apparatus main body. Is characterized by having the outlet plug of the present invention.
In this power line communication apparatus, by adopting the outlet plug of the present invention, a line filter circuit using a common mode choke coil or the like can be incorporated at low cost while maintaining good electrical characteristics. As a result, it is possible to effectively reduce the occurrence of a leakage electromagnetic field by suppressing the common mode current and the like in power line communication. In addition, the structure can be easily disassembled and modified for communication equipment at low cost.

The present invention has the following effects.
That is, according to the outlet plug according to the present invention, the air layer is formed at least in the inner region of the magnetic core in the peripheral region of the magnetic core. The contact state of the core member is reliably maintained, and good electrical characteristics are maintained. Therefore, an outlet plug with a built-in circuit such as a line filter having high reliability at low cost can be obtained. In addition, the air layer around the magnetic core can reduce the electrostatic capacity and realize an outlet plug suitable for high-frequency communication. In particular, in the power line communication device using the outlet plug of the present invention, a line filter circuit such as a common mode choke coil for suppressing a leakage electromagnetic field can be built in while maintaining low cost and good electrical characteristics.

A first embodiment of an outlet plug and a power line communication device according to the present invention will be described below with reference to FIGS.
As shown in FIGS. 1 and 2, the outlet plug 1 according to the present embodiment is connected to a power line L disposed in a wall W in a building such as a general house through an outlet jack 2 on the wall W, for example. The outlet plug of the AC cable 5 is used in a power line communication device (electronic device) 3 that performs data communication by differential transmission via the power line L.

The power line communication device 3 includes a device main body 4 such as a modem having a transmission / reception function by power line communication, and an AC cable 5 connected to the device main body 4. The power line communication device 3 also receives power supply via the power line L.
The AC cable 5 includes the outlet plug 1 that can be connected to the outlet jack 2 of the power line L, and an AC cable body 6 that connects the outlet plug 1 and the apparatus body 4.

  As shown in FIG. 2, the outlet plug 1 has a pair of plug terminals 7 that can be inserted into a pair of outlet jacks 2 of the power line L, and one end connected to the pair of plug terminals 7 and an AC line 6 a of the AC cable body 6. A line filter circuit 11 having a common mode choke coil 10 composed of a pair of signal lines 8 having the other end connected to each other, a magnetic core 9 in which the pair of signal lines 8 are wound in a cancel winding, A sealing resin 12 that covers the magnetic core 9 and is housed inside is provided.

  The line filter circuit 11 includes the common mode choke coil 10 and a pair of capacitors C connected in parallel to the pair of signal lines 8 with the common mode choke coil 10 interposed therebetween. That is, the capacitor C is stretched over and connected to the pair of signal lines 8 so as to sandwich the common mode choke coil 10.

As shown in FIG. 3, the magnetic core 9 is formed by bringing both ends of a pair of split core members 9 a having a U-shape or an arc shape into contact with each other so as to be in contact with each other. The split core member 9a is held in contact with a crimping spring 13 that urges the split core member 9a in the abutting direction.
Further, the pair of signal lines 8 are wound around the bobbin 14 by bifilar winding, and a pair of split core members 9a are passed through the bobbin 14 so that their ends are brought into contact with each other, thereby being similar to the toroidal core. Is formed as a common mode choke coil 10.
An equivalent circuit of the line filter circuit 11 having the common mode choke coil 10 is shown in FIG.

As the sealing resin 12, for example, a synthetic resin such as an epoxy resin is used.
In the peripheral region of the magnetic core 9, that is, in the inner region and the outer vicinity region of the magnetic core 9, an air layer AR is formed inside surrounded by the foam sheet 15. As the foam sheet 15, for example, “Riva Alpha” (registered trademark, manufactured by Nitto Denko Corporation), which is a heat release sheet, is used. The foam sheet 15 has an adhesive surface similar to the adhesive sheet. However, since a foamed resin is used as the adhesive on the adhesive surface, the adhesive force is lost due to foaming by heating, and the foam sheet 15 is easily peeled off.

  Specifically, the periphery of the common mode choke coil 10 is hermetically bonded and wrapped with the foam sheet 15 in this state, and in this state, the entire line filter circuit 11 is sealed by the sealing resin 12 and the base end portion of the plug terminal 7 and the AC wire 6a. It seals and integrates with the front-end | tip part of. At this time, the sealing resin 12 is not injected into the interior covered with the foam sheet 15, and an air layer AR is formed in the internal space. In addition, the adhesive of the foam sheet 15 is foamed by heating with the high-temperature sealing resin 12 at the time of sealing, and the adhesive force on the adhesive surface is lost, so that the foam sheet 15 is peeled off from the common mode choke coil 10 and the common mode A gap of the air layer AR is also formed around the choke coil 10.

  As described above, in the present embodiment, the air layer AR is formed in the peripheral region of the magnetic core 9, particularly in the inner region of the magnetic core 9, so that it depends on the solidification process of the sealing resin 12 and the temperature change after molding. Even if the expansion and contraction occurs, a stress is applied from the outer sealing resin 12 of the magnetic core 9 toward the inner air layer AR, and thus a force acts in a direction in which both ends of the pair of split core members 9a are abutted. For this reason, the contact state of a pair of division | segmentation core member 9a is hold | maintained reliably, and a favorable electrical property is maintained. Further, since the periphery (especially the inner region) of the magnetic core 9 is the air layer AR, the entire dielectric constant can be reduced as compared with the case where all of the sealing resin 12 is filled, and the capacitance is reduced. Reduced and suitable for high-frequency communication.

  Further, by adopting the outlet plug 1 of the present embodiment as the outlet plug of the AC cable 5 used in the power line communication device 3, the line filter circuit 11 using the common mode choke coil 10 can be manufactured at low cost and with good electricity. It can be built in while maintaining the characteristics. As a result, it is possible to effectively reduce the occurrence of a leakage electromagnetic field by suppressing the common mode current and the like in power line communication. In addition, the structure can be easily disassembled and modified for communication equipment at low cost.

  Next, second and third embodiments of the outlet plug and the power line communication apparatus using the same according to the present invention will be described below with reference to FIGS. 5 and 6. In the following description of each embodiment, the same constituent elements described in the above embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  The difference between the second embodiment and the first embodiment is that, in the first embodiment, the air layer AR is formed in the internal space in which the magnetic core 9 is hermetically covered with the foamed sheet 15. In the outlet plug 21 of the second embodiment, as shown in FIG. 5, foamed resin 25 such as sponge is packed inside the magnetic core 9, and the air layer AR is formed by a large number of pores inside the foamed resin 25. The sealing resin 12 is sealed so as to cover the outer periphery of the magnetic core 9 while being secured and formed.

  That is, in the second embodiment, the foamed resin 25 is packed in the inner region of the magnetic core 9, and the air layer AR is obtained in a state where a large amount of air is held in the pores of the foamed resin 25 that is porous. In addition, the area of the air layer AR can be secured inside the magnetic core 9 when the sealing resin 12 is molded. When producing the outlet plug 21 of the second embodiment, the line filter circuit 11 is molded with the sealing resin 12 in a state in which the foamed resin 25 is previously packed in the inner region of the magnetic core 9. The sealing resin 12 is not injected up to the inner region of the magnetic core 9, and the air layer AR in the internal hole is secured by the foamed resin 25. Further, as the foamed resin 25, an olefin type, a styrene type (foamed polystyrene, etc.), a vinyl chloride type, or the like is appropriately selected. In this embodiment, a sponge is employed.

  The difference between the third embodiment and the first embodiment is that, in the first embodiment, the air layer AR is formed inside the airtightly covered with the foam sheet 15, whereas the outlet plug of the third embodiment. In FIG. 6, as shown in FIG. 6, an air case AR is formed and secured in an airtight casing by an insulating case 35 covering the common mode choke coil 10. That is, in the third embodiment, by molding the sealing resin 12 in a state where the common mode choke coil 10 is airtightly accommodated in the case 35 in advance, the sealing resin 12 to the magnetic core 9 by the case 35 is performed. The air layer AR can be formed around the common mode choke coil 10 in the case 35.

As mentioned above, although embodiment of this invention was described with reference to drawings, it is not limited to the said embodiment about a concrete structure, The design change etc. of the range which does not deviate from the summary of this invention are possible. .
For example, in each of the above embodiments, the signal line 8 is wound around the magnetic core 9 by bifilar winding, but may be wound by cancellation winding.
Further, the circuit element using the magnetic core 9 is not limited to the common mode choke coil 10 that suppresses the common mode current as a function, and the signal line is connected to the magnetic core 9 formed by abutting the split core member 9a. As long as 8 is wound, a circuit element having other functions may be used.

1 is a configuration diagram illustrating a power line communication device in a state of being connected to a power line in the outlet plug and the power line communication device according to the first embodiment of the present invention. In 1st Embodiment, it is an internal block diagram which shows an outlet plug. FIG. 3 is a top view showing a common mode choke coil in the first embodiment. In this embodiment, it is a circuit diagram which shows the equivalent circuit of a line filter circuit. It is an internal block diagram which shows an outlet plug in the outlet plug and power line communication apparatus of 2nd Embodiment which concern on this invention. It is an internal block diagram which shows an outlet plug in the outlet plug and power line communication apparatus of 3rd Embodiment which concerns on this invention.

Explanation of symbols

1, ..., 31 ... Outlet plug, 2 ... Outlet jack, 3 ... Power line communication device, 4 ... Device main body, 5 ... AC cable, 6 ... AC cable main body, 8 ... Signal line, 9 ... Magnetic core, 11 ... Line Filter circuit, 12 ... Sealing resin, 15 ... Foam sheet, 25 ... Foam resin, 35 ... Case, AR ... Air layer, L ... Power line, W ... Wall

Claims (4)

A pair of plug terminals that can be plugged into a pair of power line jacks;
A pair of signal lines having one end connected to the pair of plug terminals and the other end connected to an AC cable of the electronic device;
A magnetic core in which a pair of the signal lines are wound in a bifilar winding or a cancel winding, with the ends of the pair of split core members butting each other configured in an annular shape,
A sealing resin that covers and covers the signal line and the magnetic core;
An outlet plug, wherein an air layer is formed in at least an inner region of the magnetic core in a peripheral region of the magnetic core. The outlet plug according to claim 1,
An outlet plug, wherein the air layer is formed of a foamed resin. The outlet plug according to claim 1,
A case for airtightly storing the magnetic core;
The sealing resin seals the magnetic core together with the case;
An outlet plug, wherein the air layer is formed in the case. A power line communication device that performs data communication via a power line,
An apparatus main body having a transmission / reception function by power line communication;
An AC cable connected to the device body,
The power cable communication device, wherein the AC cable includes the outlet plug according to any one of claims 1 to 3.

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