JP6170466B2 - Surge protector - Google Patents

Description

  The present invention relates to a surge protection device, and more particularly, to a surge protection device for protecting communication equipment and home appliances from a surge.

  Conventionally, surge protection devices provided with surge protection elements such as varistors and arresters to protect telecommunications equipment such as ICT (Information and Communication Technology) devices and home appliances such as air conditioners and refrigerators from lightning surges. There is known a technique for installing a device near a power plug of a communication device or home appliance.

  FIG. 1 shows an example of a circuit including a conventional surge protection device. A conventional surge protection device 1 is installed between an AC power source 2 and a load 3 to which an AC current output from the AC power source 2 is supplied. The conventional surge protection device 1 detects the temperature of the varistor 11 whose resistance value decreases when the applied voltage exceeds a certain value, and the surface temperature of the varistor 11, and blows when the detected temperature exceeds a certain value. A thermal fuse 12 and a current fuse 13 that blows when an input current exceeds a certain current value are provided.

  Normally, when an alternating current is supplied from the alternating current power source 2 to the load 3, the resistance value of the varistor 11 is very high, so that the current value flowing through the varistor 11 is close to zero. On the other hand, when a lightning surge occurs, an abnormally high voltage is applied to the two wires connected between the AC power supply 2 and the load 3, and the resistance value of the varistor 11 in the conventional surge protection device 1 is reduced. To do. Therefore, a large current flows through the varistor 11 and a large current does not flow through the load 3, and the load 3 can be protected from lightning surge. Here, when a lightning surge occurs in the surge protection device 1, the varistor 11 may be destroyed and deteriorated, and two electric wires connected between the AC power supply 2 and the load 3 may be short-circuited.

  In the conventional surge protection device 1, consider a case where the varistor 11 is deteriorated and two electric wires connected between the AC power supply 2 and the load 3 are short-circuited. In a state where an alternating current from the alternating current power supply 2 is supplied to the load 3, a large short-circuit current flows through the deteriorated varistor 11, and a sufficient current is not supplied to the load 3. Therefore, since a large short-circuit current flows through the current fuse 13 connected to the varistor 11 by the configuration of the conventional surge protection device 1, the current fuse 13 is melted and the current flowing through the varistor 11 is cut off, so that it is suitable for the load 3. An electric current can be supplied.

  In the conventional surge protection device 1, consider a case where the varistor 11 is deteriorated and two electric wires connected between the AC power supply 2 and the load 3 are connected through the varistor 11 with low impedance. When the alternating current from the alternating current power source 2 is supplied to the load 3 and the current flowing through the varistor 11 is a current amount that does not reach the current fuse 13, the degraded varistor 11 is relatively large. Current will flow continuously. If a current continuously flows through the deteriorated varistor 11, the varistor 11 may overheat and ignite. Further, when the varistor 11 is covered with an insulating resin container (not shown), if the varistor 11 ignites, it may burn into the insulating resin and the flame may expand outside the container.

Therefore, a technique is known in which the varistor 11 is housed in a flame retardant resin container to suppress the spread of fire to the outside. However, if a current continues to flow through the varistor 11, heat continues to be generated in the varistor 11, and heat is continuously applied to the flame retardant resin container. As a result, the flame retardant resin container is deformed and the outer side of the varistor 11 is deformed. There is also the possibility of the flame spreading.
In the conventional surge protection device 1, the varistor 11 is prevented from firing by using the thermal fuse 12 in preparation for the case where the varistor 11 is overheated and cutting off the current by the thermal fuse 12. Specifically, the thermal fuse 12 is installed so as to be adjacent to the varistor 11. When the varistor 11 is overheated, the thermal fuse 12 is blown, the supply of current to the varistor 11 is stopped, and the generation of heat of the varistor 11 can be suppressed, so that the varistor 11 is prevented from firing. It becomes possible. Therefore, the conventional surge protection device 1 includes the thermal fuse 12 to prevent the outside of the varistor 11 from spreading due to a flame ignited due to abnormal overheating of the varistor 11 (see Non-Patent Document 1). reference).

By Soichiro Onuki, “Examples of investigations into the causes of ignition accidents in electrical products”, 2010 Product Safety Center Product Safety Business Report Meeting, November 2010, <URL: http://www.nite.go.jp/jiko/ seika / 2010 / data / 5_1_kaminari.pdf>

  However, in the conventional surge protection device 1, for example, when the varistor 11 is destroyed due to a lightning surge, the varistor 11 may generate a spark and ignite. When the varistor 11 is ignited, the temperature of the surface of the varistor 11 rapidly rises, and there is a problem that the ignition of the varistor 11 may spread outside the varistor 11 before the thermal fuse 12 is blown.

  Further, when the varistor 11 is covered with a resin container, the resin container is deformed by the heat of ignition of the varistor 11, and a gap is generated in the resin container. As a result of the flammable material adhering and igniting, there was a problem that the spread of fire to the outside occurred.

  This invention is made | formed in view of such a problem, The place made into the objective is to provide the surge protective device for suppressing the fire spread to the outer side of a surge protective device.

  In order to achieve the above object, the present invention provides a surge protection device according to a first aspect of the present invention, wherein the surge protection device is connected to a surge protection element and one electrode of the surge protection element. An electrode, a second electrode connected to the other electrode of the surge protection element, and a metal container for sealing the surge protection element, wherein the first electrode is inserted into the first lid portion The second electrode is inserted into the second lid, the inner and outer surfaces of the metal container are coated with an insulating material, and the metal container is coated with the insulating material. The outside is covered with a heat insulating material so that a part of the inserted first electrode and a part of the inserted second electrode are exposed.

  As described above, according to the present invention, it is possible to suppress the spread of fire to the outside by a sealed metal container even if the varistor ignites. Further, according to the present invention, it is possible to prevent electric shock from the varistor by the insulating material and to suppress the deterioration of the insulating material.

It is a figure which shows an example of the circuit containing the conventional surge protection apparatus. It is a figure which shows an example of the circuit containing the surge protection apparatus concerning the 1st Embodiment of this invention. It is a figure which shows an example of the perspective view of the surge protection apparatus concerning the 1st Embodiment of this invention. It is a figure which shows an example of the surge protection apparatus concerning the 1st Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<First Embodiment>
FIG. 2 shows an example of a circuit including the surge protection device according to the first embodiment of the present invention. The surge protection device 4 according to the first embodiment of the present invention is installed between an AC power supply 2 and a load 3 to which an AC current output from the AC power supply 2 is supplied.

  FIG. 3 shows an example of a perspective view of the surge protection device according to the first embodiment of the present invention. FIG. 4 shows an example of the surge protection device according to the first embodiment of the present invention. FIG. 4A shows an example of an overall plan view of the surge protection device 4 according to the first embodiment of the present invention, and FIG. 4B shows the surge protection device 4 according to the first embodiment of the present invention. An example of the entire AA ′ cross-sectional view of FIG. The surge protection device 4 according to the first embodiment of the present invention includes a first electrode 401 and a second electrode 402 respectively connected to two electric wires connected between the AC power supply 2 and the load 3. And a varistor 41 connected to the first electrode 401 and the second electrode 402. The surge protection device 4 according to the first embodiment of the present invention includes a metal container 420 that seals the varistor 41 and a heat insulating container 430 that is formed of a heat insulating material so as to cover the entire metal container 420. .

  The metal container 420 is coated (film treatment) with, for example, Teflon (registered trademark) which is a heat-resistant and insulating material 440. Therefore, even if the varistor 41 deteriorates in the metal container 420 and a part of the varistor 41 contacts the inside of the metal container 420, the coated insulating material 440 causes an electric shock on the outer surface of the metal container 420. To prevent that. In addition, a current may flow from the electrode to the metal container 420 between the first electrode 401 and the metal container 420 (B) and between the second electrode 402 and the metal container 420 (C). Suppressed. In addition, the material which comprises the metal container 420 may have an insulation characteristic.

  FIG. 4 (c) shows a plan view of a connection example between the first electrode 401 and the second electrode 402 and the varistor 41 according to the first embodiment of the present invention, and FIG. An AA ′ sectional view in the example of connection of the 1st electrode 401 and 2nd electrode 402 and varistor 41 concerning a 1st embodiment is shown. One electrode of the varistor 41 is connected to the first electrode 401, and the other electrode of the varistor 41 is connected to the second electrode 402.

  FIG. 4 (e) shows an example of a plan view of the metal container 420 according to the first embodiment of the present invention, and FIG. 4 (f) shows a metal container 420 according to the first embodiment of the present invention. An example of AA 'sectional drawing of is shown. The metal container 420 includes a first lid portion 421 having a hole into which the first electrode 401 is inserted, a second lid portion 422 having a hole into which the second electrode 402 is inserted, and a cylindrical portion 423. . The 1st cover part 421 and the 2nd cover part 422 are carrying out the disk shape which hollowed out the hole which can insert an electrode. The metal container 420 has a shape in which the first lid portion 421 and the second lid portion 422 are joined to the top portion and the bottom portion of the cylindrical portion 423. In the first embodiment of the present invention, the varistor 41 connected to the first electrode 401 and the second electrode 402 is accommodated in the cylindrical portion 423 of the metal container 420, and the metal container 420 is sealed. It is in a state. That is, the varistor 41 is sealed by the metal container 420.

  FIG. 4 (g) shows an example of a plan view of the heat insulating container 430 according to the first embodiment of the present invention, and FIG. 4 (h) shows a heat insulating container 430 according to the first embodiment of the present invention. An example of AA 'sectional drawing of is shown. The heat insulating container 430 includes an upper lid part (third lid part) 431, a lower lid part (fourth lid part) 432, and an intermediate cylinder part 433. The upper lid portion 431 of the heat insulating container 430 has a thick cylindrical shape, and the first electrode 401 can be inserted into the upper lid portion 431. The same applies to the lower lid portion 432 of the heat insulating container 430. The second electrode 402 can be inserted into the lower lid portion 432. The middle cylinder portion 433 also has a thick cylindrical shape, and can accommodate the metal container 420 coated with the insulating material 440.

  A part of the first electrode 401 is exposed at the upper lid part 431 of the heat insulating container 430, and a part of the second electrode 402 is exposed at the lower cover part 432 of the heat insulating container 430. That is, the outside of the metal container 420 coated with the insulating material 440 has a part of the first electrode 401 inserted into the first lid part 421 and a second part inserted into the second lid part 422. A part of the electrode 402 is covered with a heat insulating material so as to be exposed. From another point of view, a metal container 420 coated with an insulating material 440 includes a part of the first electrode 401 inserted into the upper lid portion 431 and the second electrode 402 inserted into the lower lid portion 432. It can also be said that a part of is stored in the heat insulating container 430 so as to be exposed to the outside of the heat insulating container 430.

  The exposed first electrode 401 and second electrode 402 are respectively connected to two electric wires connected between the AC power source 2 and the load 3.

  In the surge protection device 4 according to the first embodiment of the present invention, for example, the varistor 41 is destroyed by receiving a lightning surge, the varistor 41 generates a spark and ignites, and the temperature of the surface of the varistor 41 rapidly increases. Suppose you did. With the configuration of the surge protection device 4 according to the first embodiment of the present invention, even if the varistor 41 is ignited due to a rapid temperature rise, the heat is blocked by the sealed metal container 420, and the outside of the surge protection device 4. Fire spread to is suppressed. Further, since the metal container 420 is hermetically sealed, it is possible to prevent the combustible gas or flame generated by the ignition of the varistor 41 from flowing out of the metal container 420.

  Further, since the outer and inner surfaces of the metal container 420 are coated with an insulating material, the risk of electric shock in the metal container 420 can be reduced. Furthermore, since the surface of the metal container 420 is covered with a heat insulating material, the insulating material coated on the surface of the metal container 420 is protected from heat, and the insulating material is deformed or deteriorated by heat. It becomes possible to prevent.

  In the surge protection device 4 according to the present embodiment, the varistor 41 is used. However, the varistor 41 may be replaced with an arrester or another surge protection element.

  Moreover, although the surge protective device 4 concerning this embodiment is an external shape which combined the cylinder in FIG. 3, it is not restricted to this.

  According to this embodiment, even if the varistor ignites, it is possible to suppress the spread of fire to the outside by the sealed metal container. Further, according to the present embodiment, it is possible to prevent electric shock from the varistor by the insulating material and to suppress the deterioration of the insulating material.

  The surge protection device according to another embodiment of the present invention may include a current fuse and a thermal fuse. The current fuse may be inserted between the two electric wires connected between the AC power supply 2 and the load 3 and the first electrode 401 or the second electrode 402. The thermal fuse is inserted between the two electric wires connected between the AC power supply 2 and the load 3 and the first electrode 401 or the second electrode 402 and is adjacent to the heat insulating container 430. It may be installed as follows.

DESCRIPTION OF SYMBOLS 1, 4 Surge protection device 2 AC power supply 3 Load 11, 41 Varistor 12 Thermal fuse 13 Current fuse 401 1st electrode 402 2nd electrode 420 Metal container 421 1st cover part 422 2nd cover part 423 Cylindrical part 430 Thermal insulation container 431 Upper lid part 432 Lower lid part 433 Middle cylinder part 440 Insulating material

Claims (2)

A surge protection device,
A surge protection element;
A first electrode connected to one electrode of the surge protection element;
A second electrode connected to the other electrode of the surge protection element;
A first lid and a second lid, and a metal container for sealing the surge protection element;
The first electrode is inserted into the first lid, the second electrode is inserted into the second lid,
The inner and outer surfaces of the metal container are coated with an insulating material,
The outside of the metal container coated with the insulating material has a part of the first electrode inserted into the first lid part and a part of the second electrode inserted into the second lid part. A surge protection device that is covered with a heat insulating material so as to be exposed. A heat insulating container for storing the metal container;
The heat insulating container has a third lid portion and a fourth lid portion,
The first electrode is inserted into the third lid, the second electrode is inserted into the fourth lid,
The metal container coated with the insulating material has a part of the first electrode inserted into the third lid part and a part of the second electrode inserted into the fourth lid part. The surge protection device according to claim 1, wherein the surge protection device is housed in the heat insulating container so as to be exposed to the outside of the heat insulating container.

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