JP2013229288A - Arc-extinguishing resin molding member and circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an arc-extinguishing resin molding member having excellent breaking performance durability in addition to excellent strength, heat resistance and pressure resistance, generating thermal decomposition gas required for arc-extinguishing, and capable of minimizing damage on the housing of the circuit breaker by suppressing generation of gas, and to provide a circuit breaker having excellent breaking performance and durability thereof, and capable of minimizing damage on the housing.SOLUTION: The arc-extinguishing resin molding member contains acicular or fibrous titanium oxide in resin. The circuit breaker includes an extinguishing device including the arc-extinguishing resin molding member.

Description

  TECHNICAL FIELD The present invention relates to an arc extinguishing resin molded member, and a circuit breaker such as a circuit breaker and a leakage breaker using the same.

  Circuit breakers such as circuit breakers and earth leakage breakers open the primary circuit when abnormal current flows through the secondary circuit (load, circuit) due to overload or short circuit. It is an apparatus used for avoiding damage to the load circuit and the electric wire by shutting off the power supply from.

  In such a circuit breaker, when the movable contact of the movable contactor and the fixed contact of the fixed contactor are separated when an excess current or a rated current is applied, an arc is generated between the two. Here, FIGS. 8A and 8B schematically show the state of a circuit breaker in the vicinity where an arc is generated during interruption. FIG. 8 is a schematic diagram showing a state of the arc-extinguishing device in a general circuit breaker when the arc-extinguishing device is interrupted. (A) is a cross-sectional view of the arc-extinguishing device, and (b) is a side view of the arc-extinguishing device (( a) corresponding to a cross-sectional view taken along line Ib-Ib). Since the arc becomes a thermal and electromagnetic force load on the components of the circuit breaker, it is necessary to extinguish the arc quickly. Therefore, in order to advance the arc extinguishing promptly, as shown in FIGS. 8A and 8B, the arc extinguishing is provided around the movable contact 31 of the movable contact 30 and the fixed contact 33 of the fixed contact 32. A resin molded member 34 is disposed. As shown in FIG. 8A, the arc-extinguishing resin molded member 34 is disposed so as to sandwich the movable contact 30 and the fixed contact 32 from both sides, for example. When the arc-extinguishing resin molded member 34 is exposed to an arc, the material itself constituting the member is decomposed to generate a gas, and the arc is cooled by the generated gas and the arc is stretched by blowing the generated gas. This contributes to extinguishing the arc.

  Further, as shown in FIG. 9, the arc-extinguishing resin molded member 34 extends an arc generated between the movable contact 31 and the fixed contact 33 and guides it to an arc-extinguishing device having an arc-extinguishing plate 35 (grid). Also plays a role. The arc-extinguishing apparatus shown in FIG. 9 is configured such that a plurality of arc-extinguishing plates 35 made of magnetic metal are stacked and arranged with a gap therebetween, and each arc-extinguishing plate 35 is provided with a notch 36. . The arc-extinguishing resin molded member 34 is arranged so as to sandwich the movable contact 31 and the fixed contact 33 (see FIG. 8), and draws and divides the arc 37 generated between the contacts, thereby generating an electrode drop voltage. In addition, it functions to limit (lower) overcurrent by cooling the arc.

  As a material for the arc-extinguishing resin molded member 34, for example, Patent Document 1 discloses the use of materials such as nylon and Teflon (registered trademark). Patent Document 2 discloses that a resin having a high heat resistance is blended with an inorganic filler for improving the pressure strength.

JP 2007-149486 A Japanese Patent Laid-Open No. 7-302535

  However, although the conventional arc-extinguishing resin molded member 34 is improved in properties such as strength, heat resistance and pressure resistance, there is a problem that the durability of the interruption performance is not sufficient. In fact, the conventional arc-extinguishing resin molded member 34 cannot be continuously interrupted a specified number of times in an overload interruption test that is an indicator of durability of interruption performance. Further, the conventional arc-extinguishing resin molded member 34 cannot suppress an increase in internal pressure in the arc extinguishing device due to pyrolysis gas generated during arc extinction, and therefore the casing of the circuit breaker is damaged by the increase in internal pressure during arc extinction. There is also a problem that it is easy.

The present invention has been made in order to solve the above-described problems. In addition to strength, heat resistance, and pressure resistance, the present invention is excellent in durability of interruption performance and generates pyrolysis gas necessary for arc extinction. On the other hand, an object of the present invention is to provide an arc extinguishing resin molded member capable of suppressing the amount of generated gas and suppressing the breakage of the casing of the circuit breaker.
Another object of the present invention is to provide a circuit breaker that is excellent in breaking performance and durability and that can suppress damage to the casing.

As a result of diligent research to solve the above problems, the present inventors have found that inorganic fillers are based on the knowledge that the types of inorganic fillers blended in the resin affect properties such as durability of the barrier performance. It has been found that all the above problems can be solved by using acicular or fibrous titanium oxide as a material.
That is, the present invention is an arc-extinguishing resin molded member comprising needle-like or fibrous titanium oxide in a resin.
Moreover, this invention is a circuit breaker provided with the arc-extinguishing apparatus containing said resin molding member for arc-extinguishing.

According to the present invention, in addition to strength, heat resistance, and pressure resistance, the circuit breaker is excellent in durability of interruption performance and generates pyrolysis gas necessary for arc extinction, while suppressing the amount of generated gas. The arc-extinguishing resin molded member that can suppress the breakage of the casing can be provided.
Moreover, according to this invention, the circuit breaker which is excellent in interruption | blocking performance and its durability, and can suppress the failure | damage of a housing | casing can be provided.

It is a schematic diagram of the arc-extinguishing resin molded member of the present invention after being exposed to an arc, (a) is a top view and (b) is a cross-sectional view. It is a schematic diagram of the conventional arc-extinguishing resin molded member after being exposed to an arc, (a) is a top view and (b) is a cross-sectional view. It is a schematic diagram showing the mode at the time of interruption | blocking of the arc-extinguishing apparatus in the circuit breaker of this invention, (a) is sectional drawing, (b) is sectional drawing along Ib-Ib of (a). Equivalent). It is a perspective view of the arc-extinguishing apparatus of the present invention in which a plurality of arc-extinguishing plates having notches are stacked at regular intervals. It is sectional drawing showing the mode at the time of the contact of the circuit breaker of this invention (on state). It is the elements on larger scale of the circuit breaker shown in FIG. 5, Comprising: It is sectional drawing showing the mode at the time of interruption | blocking (OFF state) of a circuit breaker. It is a schematic diagram showing the positional relationship between the arc-extinguishing resin molded member and a contact pair (fixed contact and movable contact), (a) is a side view, (b) is a top view. It is a schematic diagram showing the mode at the time of interruption | blocking of the arc-extinguishing apparatus in a general circuit breaker, (a) is sectional drawing, (b) is a sectional view along Ib-Ib of (a). Equivalent). It is a perspective view of the general arc-extinguishing apparatus which used the several arc-extinguishing board with a notch by laminating | stacking with a fixed space | interval.

  Hereinafter, preferred embodiments of the arc-extinguishing resin molded member and the circuit breaker of the present invention will be described with reference to the drawings. In addition, what attached | subjected the same referential mark in description of the following drawings represents the same part or an equivalent part.

Embodiment 1 FIG.
The arc-extinguishing resin molded member is provided for the purpose of arc extinction by decomposition gas generated by exposure to arc, induction of arc to arc extinguishing plate by gas flow of decomposition gas, insulation shielding in arc extinguishing device, etc. It is a member.
1A and 1B are schematic views of the arc-extinguishing resin molded member of the present invention after being exposed to an arc, wherein FIG. 1A is a top view and FIG. 1B is a cross-sectional view. In FIG. 1, the arc-extinguishing resin molded member 1 of the present invention includes acicular or fibrous titanium oxide 2 in a resin 3. In FIG. 1, the shape of the arc-extinguishing resin molded member 1 is shown as a rectangular parallelepiped for easy understanding of the present invention. However, the shape of the arc-extinguishing resin molded member 1 is limited to a rectangular parallelepiped. However, it can be determined appropriately according to the arc extinguishing device to be used.
2A and 2B are schematic views of a conventional arc extinguishing resin molded member after being exposed to an arc, wherein FIG. 2A is a top view and FIG. 2B is a cross-sectional view. In FIG. 2, a conventional arc-extinguishing resin molded member 4 includes an inorganic filler 5 (for example, glass fiber, potassium titanate, wollastonite, etc.) in the resin 3.

  In the conventional arc-extinguishing resin molded member 4, when the electric capacity to be interrupted is large, a phenomenon in which the interrupting performance deteriorates when the interruption is repeated is observed. This is because, as shown in FIG. 2, the conventional arc-extinguishing resin molded member 4 is caused by the fact that the resin 3 is decomposed and the inorganic filler 5 remains on the surface as the interruption is repeated. it is conceivable that.

Therefore, as a result of examining the above phenomenon in detail, the present inventors have found that the above phenomenon depends on the type of the inorganic filler 5.
The arc-extinguishing resin molded member 1 of the present invention uses needle-like or fiber-like titanium oxide 2 (hereinafter abbreviated as “titanium oxide 2”), as shown in FIG. Only the titanium 2 does not remain on the surface, and the surface in which the titanium oxide 2 and the resin 3 are mixed can be maintained. This is considered to be because the surface of the arc-extinguishing resin molded member 1 is exposed to the arc, so that the titanium oxide 2 is scattered together with the decomposition gas generated by the decomposition of the resin 3. The reason why the titanium oxide 2 is likely to be scattered together with the decomposition gas of the resin 3 is that the decomposition of the resin 3 existing at the interface between the resin 3 and the titanium oxide 2 is caused by the photocatalytic ability of the titanium oxide 2 induced by arc exposure. This is presumed to be caused by the decrease in the adhesive strength of the titanium oxide 2. And since the arc-extinguishing resin molded member 1 of the present invention can hold the surface where the titanium oxide 2 and the resin 3 are mixed for a long period of time, it is possible to improve the durability of the interruption performance.
On the other hand, when using the inorganic filler 5 (for example, glass fiber, potassium titanate, wollastonite, etc.), the resin 3 present at the interface between the resin 3 and the inorganic filler 5 is not decomposed. It is presumed that the inorganic filler 5 remains on the surface of the arc-extinguishing resin molded member 4 as a result of remaining and maintaining the adhesion between the resin 3 and the inorganic filler 5.

  In the arc-extinguishing resin molded member 1 of the present invention, since the titanium oxide 2 is easily scattered along with the decomposition gas of the resin 3 by the arc exposure as described above, the surroundings of the titanium oxide 2 are exposed to the arc exposure by heat and / or light. There is no need to treat with an inorganic surface treatment agent that decomposes (for example, a surface treatment agent comprising an inorganic compound). That is, the arc-extinguishing resin molded member 1 of the present invention can be used for arc extinguishing without the titanium oxide 2 being unevenly distributed on the surface of the arc-extinguishing resin molded member 1 without depending on the decomposition force of an inorganic surface treatment agent or the like. Effective decomposition gas of the resin 3 can be continuously generated.

The titanium oxide 2 used for the arc-extinguishing resin molded member 1 of the present invention is needle-like or fibrous. If the titanium oxide 2 is not in the form of needles or fibers, the durability of the shielding performance is not sufficiently improved, and the strength that can withstand the increase in internal pressure in the arc extinguishing device during arc extinction cannot be obtained.
As used herein, “needle-like or fibrous” means that the average minor axis is 0.01 μm or more and 1000 μm or less, and the average aspect ratio (average major axis / average minor axis) is 2 or more and 2500 or less. To do. In particular, “needle” means an average major axis of 100 μm or less and an average aspect ratio of 2 to 100, and “fibrous” means an average major axis of more than 100 μm and an average aspect ratio of 100. It means the above. Here, in this specification, “average major axis” means an average value of lengths in the longitudinal direction of a plurality of titanium oxides 2 (particles) measured by microscopic observation, and “average minor axis” means a microscope It means the average value of the lengths in the short direction of a plurality of titanium oxides 2 (particles) measured by observation.

  From the viewpoint of durability of the blocking performance, preferred titanium oxide 2 is needle-shaped having an average minor axis of 0.01 μm to 5 μm and an average major axis of 0.05 μm to 50 μm. More preferable titanium oxide 2 has a needle-like shape having an average minor axis of 0.02 μm to 2 μm and an average major axis of 0.5 μm to 50 μm. The most preferable titanium oxide 2 is needle-shaped having an average minor axis of 0.05 μm to 1 μm and an average major axis of 1 μm to 10 μm. When the average minor axis of titanium oxide 2 is less than 0.01 μm or the average major axis is less than 0.05 μm, the reinforcing effect when added to the resin as a filler is small, and the effect of improving the mechanical strength may not be sufficient. If the average minor axis of titanium oxide 2 exceeds 5 μm or the average major axis exceeds 50 μm, it becomes difficult for titanium oxide 2 to scatter with the decomposition gas of resin 3 during arc exposure. As a result, the titanium oxide 2 tends to remain on the surface after the arc exposure, and the interruption performance may be deteriorated.

In the present specification, “titanium oxide 2” is a compound composed of titanium and oxygen. For example, titanium dioxide (TiO ₂ ); dititanium trioxide (Ti ₂ O ₃ ); titanium monoxide ( TiO); means having an oxygen deficient composition from titanium dioxide represented by Ti ₄ O ₇ , Ti ₅ O _{9 and the} like. Therefore, “titanium oxide 2” in the present specification does not include a composite oxide of titanium and a metal other than titanium. For example, even when a composite oxide (for example, potassium titanate) of titanium and an alkali metal (for example, potassium) is used, the durability of the blocking performance is not sufficiently improved.

  Titanium oxide 2 can be subjected to silane coupling treatment for the purpose of improving dispersibility during kneading with resin 3 and strength of arc-extinguishing resin molded member 1. The silane coupling treatment is not particularly limited, and the treatment may be performed using a known silane coupling agent. Examples of the silane coupling agent include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2 (aminoethyl) 3-aminopropylmethyldimethoxysilane, and N-2 (aminoethyl) 3-amino. And propyltrimethoxysilane. In particular, when a polyamide resin is used as the resin 3, these silane coupling agents are highly effective in increasing dispersibility during kneading, and can also be expected to improve impact strength. Moreover, these silane coupling agents can be used individually or in combination of 2 or more types.

  Titanium oxide 2 can be surface-treated with an inorganic substance for the purpose of suppressing photocatalytic activity. Examples of the inorganic material used for the surface treatment include aluminum hydroxide and aluminum oxide hydrate.

  The content of titanium oxide 2 in the arc-extinguishing resin molded member 1 is not particularly limited, but is preferably 5% by mass or more and 50% by mass or less, more preferably 10% by mass or more and 30% by mass or less. When the content of titanium oxide 2 is less than 5% by mass, the content of the arc-extinguishing component (resin 3) in the arc-extinguishing resin molded member 1 is relatively increased. As a result, the arc-extinguishing resin molded member 1 May not be strong enough. In addition, the amount of gas generated when exposed to the arc increases, the increase in internal pressure in the arc extinguishing device cannot be suppressed, and the circuit breaker casing may be damaged. On the other hand, when the content of titanium oxide 2 exceeds 50% by mass, the content of the arc-extinguishing component (resin 3) in the arc-extinguishing resin molded member 1 is relatively reduced, and as a result, the shielding performance is lowered. Sometimes.

The resin 3 used in the arc-extinguishing resin molded member 1 of the present invention is a component used for shortening the molding time in addition to improving the arc-extinguishing performance, the pressure resistance, and the arc wear resistance. The resin 3 is not particularly limited, and those known in the technical field can be used.
Examples of the resin 3 include polyolefin resins, polyolefin copolymers, polyamide resins, polyamide polymer blends, polyacetal resins, polyacetal polymer blends, aliphatic polyester resins, cellulose resins, polytetrafluoroethylene and other fluorine resins. , Urea resin, and melamine resin. These can be used alone or in combination of two or more.

  Polyolefin resins do not have an aromatic ring and are excellent in impact resistance, and are therefore effective in enhancing arc extinguishing performance and pressure resistance. Examples of the polyolefin resin include polypropylene, polyethylene, polymethylpentene, and the like. Among these, those having a small specific gravity such as polypropylene and polymethylpentene are preferable from the viewpoint of reducing the weight of the arc-extinguishing resin molded member 1. In particular, since polymethylpentene is a crystalline resin having a melting point of 240 ° C., high heat resistance can also be improved.

  Since the polyolefin-based copolymer does not have an aromatic ring, it is effective for enhancing the arc extinguishing performance. Examples of the polyolefin copolymer include an ethylene-vinyl alcohol copolymer and an ethylene-vinyl acetate copolymer. Among these, high-strength resins such as ethylene-vinyl alcohol copolymer are preferable from the viewpoint of improving the pressure strength.

  The polyamide resin means a polymer compound having an amide bond, and the present invention includes a polyamide copolymer. The polyamide resin is a high-strength resin and is effective in increasing the pressure strength. In addition, the polyamide resin is excellent in the ability to cool the arc by the gas generated by the decomposition due to the arc exposure and increase the arc voltage, and is therefore effective in suppressing the overcurrent when the large current is interrupted.

  Examples of the polyamide resin include nylon 6T, nylon 46, nylon 66, nylon MXD6, nylon 610, nylon 6, nylon 11, nylon 12, and copolymer nylon of nylon 6 and nylon 66. Among these, nylon 46 (melting point 290 ° C.) and nylon 66 (melting point 260 ° C.), which are high melting crystalline polyamides, are preferable. In particular, when the resin 3 is nylon 46, it is possible to obtain the arc-extinguishing resin molded member 1 having a high effect of continuously generating pyrolysis gas effective for arc extinction and having excellent heat resistance.

  The content of the resin 3 in the arc-extinguishing resin molded member 1 is not particularly limited, but is preferably 50% by mass or more and 95% by mass or less. When the content of the resin 3 is less than 50% by mass, the content of the arc-extinguishing component in the arc-extinguishing resin molded member 1 is relatively reduced, and as a result, the interruption performance may be deteriorated. On the other hand, when the content of the resin 3 exceeds 95% by mass, the content of the titanium oxide 2 in the arc-extinguishing resin molded member 1 is relatively reduced, resulting in a decrease in strength of the arc-extinguishing resin molded member 1. Sometimes. In addition, the amount of gas generated when exposed to the arc increases, the increase in internal pressure in the arc extinguishing device cannot be suppressed, and the circuit breaker casing may be damaged.

  The arc-extinguishing resin molded member 1 is oxidized for the purpose of improving the heat resistance such as strength improvement and heat deformation temperature (temperature at which the temperature of the sample is raised while applying a load and the deflection becomes a constant value). It is also possible to add an inorganic filler other than titanium 2 (for example, talc). The blending amount of the inorganic filler is not particularly limited as long as it does not impair the effects of the present invention.

  The arc-extinguishing resin molded member 1 can be blended with additives known in the technical field as necessary. Examples of additives include flame retardants, stabilizers, antioxidants, oxidation accelerators, ultraviolet absorbers, plasticizers, colorants, fillers, and the like. The amount of these additives is not particularly limited as long as it does not impair the effects of the present invention.

  The method for producing the arc-extinguishing resin molded member 1 is not particularly limited, and can be performed by a method well known in the art. For example, the titanium oxide 2 and the resin 3 may be kneaded and then formed into a desired shape. The molding method is not particularly limited. For example, injection molding, extrusion molding, hollow molding (blow molding), thermoforming (vacuum or pressure molding), calender molding, two or more sheets or films are stacked or bonded. Lamination molding, liquid molding, casting, powder molding, etc. that are processed into a single product.

  The arc-extinguishing resin molded member 1 may be subjected to post-treatment such as chemical treatment and physical treatment for the purpose of improving the light resistance and weather resistance of the surface, if necessary. Examples of the chemical treatment include chemical treatment, solvent treatment, coupling agent treatment, monomer / polymer coating, surface grafting, and the like. Examples of the physical treatment include ultraviolet irradiation treatment, plasma treatment, and ion beam treatment.

  Since the arc-extinguishing resin molded member 1 obtained as described above uses titanium oxide 2 as an inorganic filler, in addition to strength, heat resistance and pressure resistance, it is excellent in the durability of the interruption performance and is also extinguished. While generating the pyrolysis gas required for the arc, it is possible to suppress the amount of the generated gas and suppress the breakage of the casing of the circuit breaker.

Embodiment 2. FIG.
The circuit breaker of this invention is equipped with the arc-extinguishing apparatus containing said resin molding member for arc-extinguishing. Since the circuit breaker of the present invention is characterized by the arc-extinguishing resin molded member, conventionally known members can be used for members other than the arc-extinguishing resin molded member. Specifically, the circuit breaker of the present invention includes a fixed contact having a fixed contact, a movable contact having a movable contact, and an opening / closing mechanism that opens and closes the fixed contact and the movable contact by operating the movable contact. And an arc extinguishing device that extinguishes an arc generated when the fixed contact and the movable contact in contact with each other are separated from each other. An arc extinguishing resin molded member is disposed.

Hereinafter, preferred embodiments of a circuit breaker including the arc-extinguishing resin molded member of the present invention will be described.
3A and 3B are schematic views showing a state of the arc-extinguishing device in the circuit breaker according to the present invention when the arc-extinguishing device is interrupted. FIG. 3A is a cross-sectional view of the arc-extinguishing device, and FIG. a) corresponding to a cross-sectional view taken along line Ib-Ib). As shown in FIGS. 3A and 3B, in this arc extinguishing apparatus, the movable contact 10 provided with the movable contact 11, the fixed contact 12 provided with the fixed contact 13, the movable contact 11 and An arc-extinguishing resin molding member 14 surrounding the fixed contact 13 is disposed. 3 (a) and 3 (b), a part of the arc extinguishing resin molded member 14 is shown for convenience, but in actuality, a plate-like member is disposed oppositely via a contactor, You may arrange | position so that the said contactor may be enclosed with a character-shaped member.

  The movable contact 11 is provided on the movable side of the movable contact 10 (the side facing the fixed contact 13), and the fixed contact 13 faces the movable contact 11 of the fixed contact 12 so as to contact the movable contact 11 when energized. In the position. These contacts form a contact pair. Further, the arc extinguishing resin molded member 14 is disposed in a portion exposed to an arc generated between the movable contact 11 and the fixed contact 13 when the circuit is interrupted.

  Next, general operation of the circuit breaker will be described. 3 (a) and 3 (b), when the opening / closing mechanism (see FIGS. 5 and 6) is operated, the movable contact 10 rotates and the movable contact 11 and the fixed contact 13 are contacted or separated. By bringing the movable contact 11 and the fixed contact 13 into contact, electric power is supplied from the power source to the load. In this state, the movable contact 11 is brought into contact by pressing against the fixed contact 13 with a specified contact pressure in order to ensure the reliability of energization.

  When a large overcurrent flows in the circuit due to the occurrence of a short circuit accident or the like, the electromagnetic repulsion force on the contact surface between the movable contact 11 and the fixed contact 13 becomes very large. As a result, the electromagnetic repulsion force exceeds the contact pressure applied to the movable contact 11, the movable contact 10 rotates and the movable contact 11 and the fixed contact 13 are separated. Further, the opening distance between the fixed contact 13 and the movable contact 11 is increased by the operation of the opening / closing mechanism and the tripping device. As a result, the arc voltage increases due to an increase in arc resistance.

  In the interruption operation as described above, a large amount of energy is generated between the movable contact 11 and the fixed contact 13 by an arc in a short time (that is, several milliseconds). At this time, when the arc-extinguishing resin molded member 14 provided on the side surface of the arc extinguishing device is exposed to the arc, decomposition gas is generated, and the arc is cooled and extinguished by the generated decomposition gas.

  In general, the arc extinguishing apparatus is provided with an arc extinguishing plate together with the arc extinguishing resin molded member 14. FIG. 4 is a perspective view of an arc extinguishing apparatus using a plurality of arc extinguishing plates 15 having U-shaped or V-shaped cutout portions 16 stacked at regular intervals. Here, the arc extinguishing plate 15 is generally made of metal. Since the arc 17 generated between the movable contact 11 and the fixed contact 13 is attracted and extended by the magnetic force in the direction of the arc extinguishing plate 15, the arc voltage further increases. Further, the overcurrent is limited by taking in the arc 17 into the plurality of arc extinguishing plates 15. At this time, the decomposition gas generated from the arc extinguishing resin molded member 14 also plays a role of guiding the arc 17 to the arc extinguishing plate 15.

The above circuit breaker will be described in more detail. FIG.5 and FIG.6 is typical sectional drawing of the circuit breaker of this invention. FIG. 5 is a contacted circuit breaker (on state), and FIG. 6 is a partially enlarged view of the circuit breaker shown in FIG. 5, showing the circuit breaker being disconnected (off state).
5 and 6, the circuit breaker includes a movable contact 10 made of a conductor such as copper, aluminum, silver, a silver alloy, and iron, a movable contact 11 disposed at one end of the movable contact 10, a movable contact 11 and The fixed contact 13 to be contacted or separated, the fixed contact 12 made of a conductor such as copper on which the fixed contact 13 is disposed, and the power supply side terminal portion 18 connected to the other end of the fixed contact 12 are mainly provided. Wiring (not shown) is connected from an external power source.

  The arc extinguishing device 100 includes a plurality of arc extinguishing plates 15 (grids) made of a magnetic metal that cools and extinguishes an arc 17 generated between the movable contact 11 and the fixed contact 13, and the arc extinguishing plates 15 on both sides. The arc extinguishing side plate 20 (only one side of the arc extinguishing side plate 20 is shown in FIGS. 5 and 6) and the arc extinguishing resin molded member 14 are held. The arc extinguishing plates 15 in the arc extinguishing apparatus 100 are stacked and arranged with a gap therebetween. The arc-extinguishing resin molded member 14 is provided so as to sandwich the movable contact 11 and the fixed contact 13 from both sides in the state of contact with the circuit breaker, and is provided so as to cover most of the fixed contact 12. (See FIGS. 7A and 7B).

  Further, the circuit breaker includes, for example, an opening / closing mechanism 110 that rotates and opens the movable contact 10, a handle 21 for manually operating the opening / closing mechanism 110, a tripping device 120, a load side The terminal part 19 etc. are provided. The cover 22 and the base 23 store and / or fix the above-described members and constitute a part of the housing 27. The end plate 25 that isolates the terminal portion 18 from the housing 27 has an exhaust hole 25 a that discharges hot gas from the arc 17, and is inserted into a guide groove 24 provided in the base 23. Further, an arc runner 26 is provided for causing the arc 17 to travel to the center of the arc extinguishing plate 15.

  FIG. 7A shows a side view and FIG. 7B shows the positional relationship between the arc extinguishing resin molding member 14 and the contact pair (the fixed contact 12 and the movable contact 10). The top view of a) is shown. 7A and 7B, the arc-extinguishing resin molded member 14 is in the vicinity of a contact pair between the movable contact 11 (not shown) of the movable contact 10 and the fixed contact 13 of the fixed contact 12. The fixed contact 13 is exposed when viewed from above, and is provided so as to cover most of the fixed contact 12 exposed to the arc 17. The arc-extinguishing resin molded member 14 also functions as an insulating member that prevents the arc 17 from moving to a portion other than the fixed contact 13 of the fixed contact 12.

  The circuit breaker having the structure as described above is excellent in durability of breaking performance in addition to strength, heat resistance and pressure resistance, and generates pyrolysis gas necessary for arc extinction, while reducing the amount of gas generated. Since the arc-extinguishing resin molded member 14 that can be suppressed is provided, the shielding performance and the durability thereof are excellent, and damage to the housing can be suppressed. In particular, the arc-extinguishing resin molded member 14 provided in this circuit breaker enhances the current limiting performance by the decomposed gas generated when exposed to the arc 17 and extends the arc 17 generated in the vicinity of the contact. It works to guide to the arc extinguishing plate 15. Therefore, the energy injected into the circuit breaker at the time of overcurrent interruption such as the occurrence of an accident can be reduced, and the burden on the structure of the circuit breaker can be reduced. Therefore, it is possible to increase the capacity and size of the circuit breaker by using the arc extinguishing resin molded member 14 of the present invention.

EXAMPLES Hereinafter, although an Example demonstrates the detail of this invention, this invention is not limited by these.
(Examples 1-4)
Table 1 shows the material composition of the arc-extinguishing resin molded member produced in Examples 1-4. In Examples 1-4, nylon 46 (TS350 manufactured by DSM) was used as the resin. In Example 1, acicular titanium oxide (FTL-100 manufactured by Ishihara Sangyo Co., Ltd.) having an average minor axis of 0.1 μm and an average major axis of 1.7 μm was used as titanium oxide, and in Example 2, an average minor axis of 0 was used as titanium oxide. .2 μm and needle-like titanium oxide having an average major axis of 2.9 μm (FTL-200 manufactured by Ishihara Sangyo Co., Ltd.) are used, and in Example 3, needle-like titanium oxide having an average minor axis of 0.3 μm and an average major axis of 5.2 μm (FTL-300 manufactured by Ishihara Sangyo Co., Ltd.) In Example 4, acicular titanium oxide (FTL-200 manufactured by Ishihara Sangyo Co., Ltd.) having an average minor axis of 0.2 μm and an average major axis of 2.9 μm was treated with an aminosilane coupling agent. What was done was used.
Titanium oxide is blended with the resin in the blending amounts shown in Table 1, heated and kneaded with a side-feed type resin kneader, and pellets are produced with an extruder, and then injection molding is performed to obtain a length of 40 mm, a width of 60 mm, and a thickness. A 1 mm arc-extinguishing resin molded member was obtained.

(Comparative Examples 1-3)
Instead of titanium oxide, wollastonite (SH-800S manufactured by Kinsei Matec Co., Ltd.), potassium titanate (Tismo D manufactured by Otsuka Chemical Co., Ltd.), glass fiber (CS 3J-459 manufactured by Nitto Boseki Co., Ltd.) was used. Except for the above, an arc extinguishing resin molded member having a length of 40 mm, a width of 60 mm, and a thickness of 1 mm was obtained in the same manner as in the above example.

  Next, the arc-extinguishing resin molded members obtained in the above examples and comparative examples were placed in the circuit breakers shown in FIGS. 3 and 4, and an overload interruption test and a short circuit interruption test were performed. The overload interruption test and the short circuit interruption test were performed as follows.

(Overload interruption test)
The circuit breaker shown in FIGS. 3 and 4 is energized with a current that is six times the rated current in the ON state (for example, 600 A in the case of a circuit breaker for 100 A), and the movable contact and the fixed contact are separated by a contact opening distance L ( The arc current was generated by breaking the circuit so that the distance between the movable contact and the fixed contact was 15 to 25 mm, and the arc current was interrupted. Table 1 shows the number of successful interruptions of the arc current among the prescribed number of interruptions of the arc current (112 times). This test was performed under the condition of AC690V / 600A.

(Short-circuit interruption test)
In the closed state, an excess current of 440 V / 50 kA was applied to open the movable contact and the fixed contact to generate an arc current, and this arc current was interrupted. Table 1 shows the number of successful interruptions of the arc current out of the prescribed number of interruptions of the arc current (three times) and the presence or absence of breakage of the arc extinguishing resin molded member and the casing. The presence or absence of breakage of the arc extinguishing resin molded member and the casing was confirmed by visual observation.

  As shown in Table 1, the circuit breaker including the arc-extinguishing resin molded members of Examples 1 to 4 clears the specified number of interruptions in the overload interruption test and the short-circuit interruption test, and for arc-extinguishing in the short-circuit interruption test. The resin molded member and the casing were not damaged. Moreover, as a result of observing the surface of the arc-extinguishing resin molded member of Examples 1 to 4 after the overload interruption test and the short circuit interruption test, the surface exposed to the arc is a mixture of resin and titanium oxide uniformly. It was confirmed that

  On the other hand, the circuit breaker provided with the arc-extinguishing resin molded member of Comparative Examples 1 to 3 could not clear the specified number of interruptions in the overload interruption test. Moreover, the circuit breaker provided with the arc-extinguishing resin molded member of Comparative Examples 2 to 3 could not clear the specified number of interruptions in the short circuit interruption test. Moreover, when the surface was observed also about the resin-molding member for arc-extinguishing of Comparative Examples 1-3 after the overload interruption | blocking test and the short circuit interruption | blocking test, in Comparative Example 1, a lot of wollastonite was exposed on the surface. Therefore, in Comparative Example 1, it is considered that the blocking performance was lowered due to the lack of resin on the surface. Further, in Comparative Example 2, a surface in which the resin and potassium titanate were uniformly mixed was retained, and no specific change was observed. Therefore, in the comparative example 2, it is thought that the interruption | blocking performance fell by the influence of potassium titanate. In Comparative Example 3, partially dissolved glass fibers were exposed on the surface. Therefore, in Comparative Example 3, it is considered that the blocking performance was lowered due to the lack of resin on the surface. In particular, in Comparative Example 3, it is considered that soot deposited at the time of interruption on the exposed glass fiber provided a creeping discharge path, which hindered arc interruption.

  As can be seen from the above results, according to the present invention, in addition to strength, heat resistance and pressure resistance, it has excellent interruption performance and generates pyrolysis gas necessary for arc extinction, while the generated gas. It is possible to provide an arc extinguishing resin molded member capable of suppressing the breakage of the circuit breaker casing by suppressing the amount. Moreover, according to this invention, the circuit breaker which is excellent in interruption | blocking performance and its durability, and can suppress the failure | damage of a housing | casing can be provided.

  DESCRIPTION OF SYMBOLS 1,14 Arc-extinguishing resin molding member of this invention, Titanium oxide, 3 Resin, 4,34 Conventional arc-extinguishing resin molding member, 5 Inorganic filler, 10, 30 Movable contact, 11, 31 Movable contact, 12, 32 fixed contact, 13, 33 fixed contact, 15, 35 arc extinguishing plate, 16, 36 notch, 17, 37 arc, 18 terminal, 19 terminal, 20 arc extinguishing side plate, 21 handle, 22 cover, 23 base, 24 guide groove, 25 end plate, 26 arc runner, 27 housing.

Claims (6)

  An arc-extinguishing resin molded member comprising acicular or fibrous titanium oxide in a resin.   2. The arc-extinguishing resin molding according to claim 1, wherein the titanium oxide is acicular titanium oxide having an average minor axis of 0.02 μm to 2 μm and an average major axis of 0.5 μm to 50 μm. Element.   The arc-extinguishing resin molded member according to claim 1 or 2, wherein the resin is a polyamide resin.   The arc-extinguishing resin molded member according to claim 3, wherein the polyamide resin is nylon 46.   A circuit breaker comprising an arc extinguishing device including the arc-extinguishing resin molded member according to any one of claims 1 to 4. A stationary contact having a stationary contact; a movable contact having a movable contact; an open / close mechanism that opens and closes the stationary contact and the movable contact by operating the movable contact; the stationary contact in a contact state; A circuit breaker comprising: an arc extinguishing device that extinguishes an arc generated when the movable contact is opened;
The arc-extinguishing device is a circuit breaker in which the arc-extinguishing resin molded member according to any one of claims 1 to 4 is disposed in a portion exposed to the arc.

Images