JP5575098B2 - Insulation material molded body for arc extinguishing, and circuit breaker using the same - Google Patents

Description

  The present invention relates to an arc-extinguishing insulating material molded body used for extinguishing an arc generated from a contact when a current is interrupted, such as a circuit breaker, and a circuit breaker using the same.

  The circuit breaker and earth leakage circuit breaker open the circuit when an abnormal current flows through the secondary circuit (load, circuit) due to an overload or short circuit, and shut off the power supply from the primary side. By doing so, it is an apparatus used to avoid load circuits and electric wires from being damaged.

  In such a circuit breaker and earth leakage circuit breaker, when the contact of the movable contact and the contact of the fixed contact are separated when an excess current or a rated current is applied, an arc is generated between them. FIG. 1A and FIG. 1B schematically show a movable contact and a stationary contact in the vicinity where an arc is generated when interrupted. FIG.1 (b) is the cross section along Ib-Ib in Fig.1 (a), and also shows the side surface of the arc-extinguishing apparatus shown in FIG.1 (a) in part. Since the arc is a thermal and electromagnetic force on the circuit breaker components, it must be extinguished quickly. In order to promptly extinguish the arc, as shown in FIGS. 1 (a) and 1 (b), an arc is formed around the movable contact 2 of the movable contact 1 and the fixed contact 4 of the fixed contact 3. An arc extinguishing insulating material molded body 5 that contributes to arc extinction is disposed. As shown in FIG. 1A, the arc-extinguishing insulating material molded body 5 is disposed so as to sandwich the movable contact 1 and the fixed contact 3 from both sides, for example. When an arc extinguishing insulating material molded body is exposed to an arc, the material constituting the molding itself decomposes to generate gas, and the arc is cooled by the generated gas or blown by the generated gas. Contributes to arc extinction by stretching.

  The arc-extinguishing apparatus shown in FIG. 2 is formed by stacking a plurality of arc-extinguishing plates 6 (grids) made of magnetic metal with a gap therebetween, and each arc-extinguishing plate 6 is provided with a notch 7. ing. The arc extinguishing insulating material molded body is disposed so as to sandwich the movable contact 2 and the fixed contact 4 (see FIG. 1), and extends the arc 8 generated between the movable contact and the fixed contact, and includes an arc extinguishing plate. It plays the role of pushing into the arc extinguishing device, and also has the function of limiting (lowering) the overcurrent by generating an electrode drop voltage or cooling the arc.

  As a material of the arc extinguishing insulating material molded body, for example, in Patent Document 1 (Japanese Patent Laid-Open No. 2007-149486), a material such as nylon or Teflon (registered trademark) is used as the arc extinguishing insulating material molded body. Is disclosed. Patent Document 2 (Japanese Patent Laid-Open No. 7-302535) discloses an arc-extinguishing insulating material molded body in which an inorganic mineral is blended with a resin having high heat resistance to improve pressure resistance.

  However, although these arc extinguishing insulating material molded bodies have been improved in strength, heat resistance, pressure resistance, etc., in the overload interruption test conducted from the viewpoint of durability of interruption performance, the prescribed number of times There was a problem that blockage was impossible. Moreover, the internal pressure rise in the arc extinguishing apparatus due to the pyrolysis gas generated during arc extinction cannot be suppressed, and there is a problem that the casing of the circuit breaker is easily damaged by the internal pressure rise during arc extinguishing.

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

  It is an object of the present invention to generate a pyrolysis gas sufficient to extinguish an arc generated when a circuit is interrupted, and to suppress the amount of generated gas in order to eliminate damage to the casing and to withstand a temperature rise that occurs at that time. An object of the present invention is to provide an arc extinguishing insulating material molded body having heat resistance and pressure resistance capable of withstanding an increase in internal pressure, and a circuit breaker using the same.

The present invention is an arc-extinguishing insulating material molded body used for a circuit breaker,
Inorganic filler A that does not decompose at 1500 ° C. or less, and a matrix resin,
At least a part of the inorganic filler A is coated with an inorganic surface treatment agent that decomposes at 1500 ° C. or less,
The inorganic filler A is an arc-extinguishing insulating material molded body in which the inorganic filler A is acicular or fibrous, or includes an acicular inorganic filler B different from the inorganic filler A.

It is preferable that the inorganic surface treatment agent decomposes at 300 ° C to 1500 ° C.
The inorganic surface treatment agent is preferably aluminum hydroxide or aluminum oxide hydrate.

It is preferable that the inorganic filler A and the inorganic filler B are acicular titanium oxide.
It is preferable that the inorganic filler A is acicular titanium oxide and the inorganic surface treatment agent is aluminum hydroxide.

  The shape of the inorganic filler A is preferably a needle shape having a minor axis length of 0.01 to 5 μm and a major axis length of 0.05 to 50 μm.

The matrix resin preferably includes nylon 46.
The present invention also provides a stator having a fixed contact, a mover having a movable contact, an opening / closing mechanism for operating the mover, and extinguishing an arc generated when the fixed contact and the movable contact are separated. The present invention also relates to a circuit breaker comprising an arc extinguishing device including the arc extinguishing insulating material molded body.

  The arc extinguishing insulating material molded body of the present invention includes an inorganic filler A surface-treated with an inorganic surface treatment agent (decomposed at 1500 ° C. or less) that is decomposed by an arc (a surface treatment agent comprising an inorganic compound). As a result, the inorganic surface treatment agent of the inorganic filler A is decomposed together with the resin by the arc generated at the time of interruption, and the inorganic filler A and / or the inorganic filler B is scattered, so that the arc extinguishing can be performed even during continuous interruption. Since only the inorganic filler does not remain on the surface of the molded body and the resin and the inorganic filler are always mixed, it is possible to continue generating a resin-derived pyrolysis gas effective for arc extinguishing.

  In addition, since the amount of resin is reduced by blending the inorganic filler and the increase in internal pressure at the time of interruption can be suppressed, it is possible to suppress breakage of the casing such as a circuit breaker.

  Furthermore, by using the arc extinguishing insulating material molded body of the present invention for a circuit breaker, a circuit breaker excellent in breaking performance such as overload breaking performance and short-circuit breaking performance can be obtained.

(A) It is a front view which shows typically the mode at the time of interruption | blocking of the arc-extinguishing apparatus in this invention, (b) is typical including the cross section of the arc-extinguishing apparatus along Ib-Ib of Fig.1 (a). It is a side view. It is a perspective view which shows the OFF state of the arc-extinguishing apparatus of this invention. It is sectional drawing which shows the time of contact (an ON state) of an example of the circuit breaker of this invention. It is a fragmentary sectional view of an example of the circuit breaker of this invention shown in FIG. 3, and is a figure which shows the time of interruption | blocking (OFF state) of a circuit breaker. (A) It is a side view which shows typically an example of arrangement | positioning relationship between a stationary contact and the arc-extinguishing insulation material molding, (b) is a top view of Fig.5 (a). It is the surface view and sectional drawing which show the mode after the overload interruption test of the insulating material molding for arc-extinguishing of this invention, and the insulating material molding for arc-extinguishing of a comparative example.

  Hereinafter, the present invention will be described in detail. In the following description of the embodiments, the description is made with reference to the drawings. In the drawings of the present application, the same reference numerals denote the same or corresponding parts.

An embodiment of a circuit breaker according to the present invention will be described with reference to FIGS.
Fig.1 (a) is a front view which shows typically the mode at the time of interruption | blocking of the arc-extinguishing apparatus in the circuit breaker based on this invention, FIG.1 (b) is Ib-Ib of Fig.1 (a). It is a side view which shows typically the mode at the time of interruption | blocking of the arc-extinguishing apparatus containing the cross section along. 1 (a) and 1 (b), the movable contact 2 is provided on the fixed contact 3 side of the movable contact 1, and the fixed contact is positioned at one end of the fixed contact 3 corresponding to the movable contact 2. 4 and an arc extinguishing insulating material molding 5 is provided so as to sandwich the periphery of the movable contact 2 and the fixed contact 4. The circuit breaker according to the present invention includes an arc extinguishing unit containing a specific compound in a portion exposed to an arc generated between the movable contact 2 and the fixed contact 4 in FIGS. 1 (a) and 1 (b). Insulating material molded body 5 is provided.

  Next, the operation of the circuit breaker will be described. 1 (a) and 1 (b), the movable contact 1 and the fixed contact 4 are brought into contact with each other when the opening / closing mechanism (see FIGS. 3 and 4) operates and the movable contact 1 rotates. It is a mechanism to break apart. Electric power is supplied from the power source to the load by bringing the contacts into contact with each other. In order to ensure the reliability of energization, the movable contact 2 is pressed against the fixed contact 4 with a specified contact pressure.

  When a short circuit accident or the like occurs and a large overcurrent flows in the circuit, the electromagnetic repulsion force on the contact surface between the movable contact 2 and the fixed contact 4 becomes very strong. In order to overcome the contact pressure applied to the movable contact 2, the movable contact 1 is rotated, the movable contact 2 and the fixed contact 4 are separated, and further fixed by the operation of the opening / closing mechanism and the tripping device. As the separation distance between the contact 4 and the movable contact 2 increases, the arc voltage increases due to an increase in arc resistance.

  During such an interruption operation, a large amount of energy is generated between the movable contact 2 and the fixed contact 4 by an arc in a short time, that is, within a few milliseconds. At this time, the arc-extinguishing insulating material molded body provided on the side surface of the arc-extinguishing device is exposed to the arc to generate decomposition gas, and the arc is cooled and extinguished by the generated decomposition gas.

  FIG. 2 is a perspective view of an arc extinguishing device portion of a circuit breaker in which a plurality of arc extinguishing plates 6 having metal U-shaped or V-shaped cutout portions 7 which are arc extinguishing devices are stacked at regular intervals. It is. Since the arc 8 generated between the movable contact 2 and the fixed contact 4 is attracted and extended by the magnetic force in the direction of the arc extinguishing plate 6, the arc voltage further increases. Furthermore, by taking in the arc extinguishing plate which is an arc extinguishing device, the overcurrent is limited, the arc is extinguished, and the circuit is interrupted.

  The circuit breaker will be described in more detail. 3 and 4 are schematic cross-sectional views of an example of the circuit breaker according to the present invention. FIG. 3 shows a circuit breaker in contact (on state), and FIG. 4 shows a circuit breaker shown in FIG. It is a part, Comprising: The time of circuit breaker interruption | blocking (OFF state) is shown. 3 and 4, the circuit breaker includes a movable contact 1 made of a conductor such as copper, a movable contact 2 fixed to one end of the movable contact 1, a fixed contact 4 that contacts and separates from the movable contact 2, and a fixed contact. 4 includes a fixed contact 3 made of a conductor such as copper to which 4 is fixed, and a terminal 9 on the power supply side formed at the other end of the fixed contact 3, and wiring is connected from an external power supply.

  The arc extinguishing plates 6 in the arc extinguishing device 100 are stacked and arranged with a gap therebetween. The arc extinguishing device 100 includes a plurality of arc extinguishing plates 6 (grids) made of a magnetic metal that cools and extinguishes an arc generated between the movable contact 2 and the fixed contact 4, and an extinguishing unit that holds the grid on both sides. The arc side plate 11 (shown in FIG. 3 and FIG. 4 shows one side of the arc extinguishing side plate) and the arc extinguishing insulating material molded body 5 are configured. The arc-extinguishing insulating material molded body 5 and the arc-extinguishing side plate 11 are made of an insulating material, and the arc-extinguishing insulating material molded body 5 includes a specific material described later. The arc-extinguishing insulating material molded body 5 is provided between the movable contact 2 and the fixed contact 4 in the state of FIG. 4. The fixed contact 3 is exposed to the arc by exposing the fixed contact 4 when viewed from above. Is provided so as to cover most of the other (see FIGS. 5A and 5B).

  Further, the circuit breaker includes, for example, an opening / closing mechanism 110 for rotating and opening the movable contact 1, a handle 13 for manually operating the opening / closing mechanism 110, a trip device 120, a load The terminal part 10 etc. of the side are provided. The cover 14 and the base 15 house and / or fix the above-described components and constitute a part of the housing 18. The end plate 17 that isolates the terminal portion 9 from the inside of the housing 18 has an exhaust hole 17 a for discharging hot gas due to an arc, and is inserted into a guide groove 16 provided in the base 15.

  The arc extinguishing insulating material molded body is installed for the purpose of arc extinction of the arc by the cracked gas, induction of the arc to the arc extinguishing plate by the gas flow of the cracked gas, and insulation shielding in the arc extinguishing apparatus. In this invention, the resin mixture containing the inorganic filler A surface-treated with the inorganic surface treating agent which decomposes | disassembles in the limited temperature range is used.

  FIG. 5A shows a side view of the contact pair and FIG. 5B shows the arrangement relationship between the arc extinguishing insulating material molded body and the contact pair (fixed contact and movable contact). The top view of (a) is shown. 5 (a) and 5 (b), the arc extinguishing insulating material molded body 5 includes a movable contact 2 (not shown) of the movable contact 1 and a contact pair of the fixed contact 4 of the fixed contact 3. As shown in FIG. 5 (b), the fixed contact 4 is exposed and the other part of the fixed contact 3 exposed to the arc is covered as viewed from above. ing. This arc extinguishing insulating material molded body also functions as an insulating member for preventing the arc from moving to a portion other than the fixed contact of the fixed contact.

  Insulation materials for arc extinguishing that contain resin reinforcing fillers such as potassium titanate and wollastonite, there is a phenomenon that the interruption becomes impossible if the interruption is repeated when the interruption has a large electric capacity. It was. Accordingly, the present inventors have studied in detail the arc extinguishing insulating material molded body containing various inorganic fillers, and as a result, the arc extinguishing insulating material molded body that cannot be repeatedly interrupted and the arc extinguishing insulating material that can be used. It has been discovered that molded bodies exist and that the difference is based on the type of inorganic filler. In particular, it has been found that in an arc extinguishing insulating material molded body including an inorganic filler surface-treated with an inorganic surface treating agent that decomposes at 1500 ° C. or lower, it is possible to repeatedly cut off.

  Fig. 6 shows the difference between an arc extinguishing insulating material molded body that cannot be repeatedly interrupted and an arc extinguishing insulating material molded body surface-treated with an inorganic surface treating agent that decomposes at 1500 ° C or less after an overload interruption test. Show. FIGS. 6 (a1) and 6 (a2) respectively show a surface and a cross section of an arc-extinguishing insulating material molded body that can be repeatedly interrupted in an overload interruption test. The overload breaking test is a test that passes the circuit breaker by passing an excess current exceeding the rated current and shuts it off and succeeds the specified number of times, and details will be described later. In FIG. 6 (a2), the right side of the figure is the surface exposed to the arc generated at the time of interruption.

  Similarly, FIG. 6 (b1) and FIG. 6 (b2) show the surface and cross section of the arc extinguishing insulating material molded body that cannot be repeatedly interrupted in the overload interruption test. In the arc extinguishing insulating material molded body 5 shown in FIGS. 6 (b1) and 6 (b2), the resin component on the surface is thermally decomposed at the time of blocking, and only the inorganic filler 51 remains on the surface after blocking. On the other hand, the arc-extinguishing insulating material molded body 5 shown in FIGS. 6 (a1) and 6 (a2), which can be repeatedly cut off, has a surface in which not only the inorganic filler 51 but also matrix resin are mixed. It was. This is because, in the arc extinguishing insulating material molded body including the surface-treated inorganic filler, the surface treatment layer of the inorganic filler 51 (on the surface of the inorganic filler 51 is not left) when the arc is exposed. An inorganic surface treatment agent that decomposes at 1500 ° C. or less is exposed to an arc and thermally decomposes to disperse the inorganic filler 51, and the matrix resin and the inorganic material remain on the surface of the arc-extinguishing insulating material molded body 5 even after interruption. By mixing the filler 51, it is possible to repeatedly cut off.

  The inorganic filler treated with the inorganic surface treatment agent is bonded to the matrix resin through the inorganic surface treatment material. When this inorganic surface treatment agent decomposes when exposed to an arc, the inorganic filler loses its adhesive strength with the matrix resin. And the inorganic filler A which lost the adhesive force with matrix resin by the impact and pressure resulting from the generation | occurrence | production of the decomposition gas at the time of a surface treating agent decomposition | disassembly, or a change of a form is used from a matrix resin or an adjacent inorganic filler. Separate and scatter.

  In the present invention, since an inorganic compound (inorganic surface treatment agent) having a low decomposition temperature exists only on the surface of the inorganic filler A, at least the inorganic filler A is used until the inorganic surface treatment agent is scattered. It remains in the arc extinguishing insulating material molded body, and the rate of strength reduction of the molded body can be suppressed. Further, only the inorganic surface treatment agent present on the outermost surface of the molded body is scattered, and the inorganic filler A in the vicinity of the surface layer of the molded body is present without decreasing the amount thereof. Strength can be maintained.

  Further, for the purpose of improving the strength of the molded body, it is also possible to repeat by mixing needle-shaped (for resin reinforcement) inorganic filler B separately from inorganic filler A surface-treated with an inorganic surface treatment agent that is thermally decomposed. Blocking can be realized. This is because when the inorganic surface treatment agent of one inorganic filler A is thermally decomposed and the inorganic filler is scattered, the other inorganic filler which is not thermally decomposed is also scattered, thereby This is because the surface is always a surface in which a resin and an inorganic filler are mixed.

  The decomposition temperature of the inorganic surface treatment agent in the present invention needs to be 1500 ° C. or lower because it needs to be decomposed by arc exposure during interruption or temperature rise. Further, the lower limit of the decomposition temperature is sufficient if kneading with the resin is possible. In particular, in order to stably mix with a resin such as nylon, the inorganic surface treatment agent is preferably decomposed at a sufficiently high temperature of 300 ° C. or higher. In addition, about the inorganic surface treatment agent which decomposes | dissolves over a wide temperature range, if it contains the component decomposed | disassembled at sufficiently high temperature of 300 degreeC or more by confirming with a thermogravimetric analysis etc., 300 degreeC or more It is assumed that the inorganic surface treatment agent decomposes at a sufficiently high temperature.

  Examples of the inorganic surface treatment agent that decomposes at a temperature of 300 to 1500 ° C. include aluminum hydroxide, aluminum oxide hydrate, talc, calcium carbonate, and magnesium hydroxide.

  As a method of coating the inorganic filler A with an inorganic surface treatment agent, for example, the inorganic filler A is suspended in a solvent such as water to form a slurry, or dispersed in a solvent such as water to form a sol. After wet pulverization and classification, add a water-soluble salt of an inorganic surface treatment agent to this solvent. If the water-soluble salt is alkaline in the solvent, use an acidic solution such as sulfuric acid or hydrochloric acid, or water-soluble In the case where the salt is acidic in the solvent, a method of neutralizing with an alkaline solution such as sodium hydroxide or aqueous ammonia to precipitate and adhere the inorganic surface treatment agent on the surface of the inorganic filler A can be mentioned.

  More specifically, while the solvent containing the inorganic filler A is preferably heated to a temperature of 40 to 90 ° C, more preferably 60 to 80 ° C, a water-soluble salt of the inorganic surface treatment agent is added thereto. It is preferable to add and then neutralize by adding an alkaline aqueous solution such as sodium hydroxide or aqueous ammonia. The neutralization reaction is preferably performed while adjusting the pH of the system to 6-8. By heating to a temperature of 70 ° C. or higher after neutralization, the inorganic filler A can be coated with an inorganic surface treatment agent. The addition amount of the inorganic surface treatment agent can be appropriately adjusted according to the setting of the surface treatment amount, but is preferably in the range of 0.1 to 100% by weight with respect to the amount of the inorganic filler A, and more Preferably, it is about 1 to 10% by weight.

  The decomposition temperature of the inorganic filler A is higher than 1500 ° C. Examples of the inorganic filler A include silicate minerals such as acicular titanium oxide and wollastonite. In particular, acicular titanium oxide and wollastonite are preferable. This is to show excellent performance in terms of the resin reinforcing effect. The same thing can be used also as the below-mentioned inorganic filler B. The inorganic filler A and the inorganic filler B are preferably wollastonite.

  Moreover, it is preferable that the inorganic filler A is acicular or fibrous. This is because the arc extinguishing insulating material molded body obtains a strength that can withstand the internal pressure rise inside the arc extinguishing device and the wind pressure caused by the decomposition gas during arc exposure. In particular, the needle shape is preferable from the viewpoint of the performance of scattering at the time of blocking. However, in the case of adding a needle-like inorganic filler B (an inorganic filler not coated with an inorganic surface treatment that decomposes at a temperature of 1500 ° C. or lower) as an inorganic filler for reinforcement separately from the inorganic filler A. The inorganic filler A to be surface-treated does not necessarily have to be needle-like or fibrous.

  When the inorganic filler A (before surface treatment) and the inorganic filler B used in the present invention are needle-shaped, the major axis length is preferably 0.01 to 50 μm and the minor axis length is 0.01 to 5 μm. In the case of a fiber, the major axis length is preferably 5 to 200 μm and the minor axis length is 0.1 to 30 μm. In the case of a granular shape, the particle diameter is preferably 0.5 to 50 μm. Is.

  In the arc extinguishing insulating material molded body of the total amount of inorganic filler A and inorganic surface treatment agent (when inorganic filler B is included, the total amount of inorganic filler A, inorganic surface treatment agent and inorganic filler B) The occupying ratio is preferably 5 to 50% by weight. If it is less than 5% by weight, a sufficient resin strength strengthening effect cannot be obtained, and if it is more than 50% by weight, the constituent ratio of the resin component in the arc extinguishing insulating material molded body decreases, and the pyrolysis gas Since the amount is reduced, sufficient arc extinguishing performance cannot be obtained.

  From the above, the inorganic filler A surface-treated with an inorganic surface treatment agent is preferably acicular titanium oxide surface-treated with aluminum hydroxide or wollastonite surface-treated with aluminum hydroxide.

  The matrix resin contained in the arc extinguishing insulating material molding is used to improve arc extinguishing performance, pressure resistance and arc wear resistance, and to shorten the molding time. The arc extinguishing insulating material molded body preferably contains 50% by weight or more of a matrix resin. Components contained in the matrix resin include, for example, polyolefins, polyolefin copolymers, polyamides, polyamide polymer blends, polyacetal and polyacetal polymer blends, aliphatic polyester resins, cellulose resins, polytetrafluoroethylene and other fluorine-based compounds. Resins, urea resins, melamine resins, and the like and mixtures thereof are used.

  Polyolefin does not have an aromatic ring and is excellent in impact resistance, so it is used to satisfy arc extinguishing performance and pressure resistance. Specific examples thereof include polypropylene, polyethylene, polymethylpentene and the like. Among them, those having a small specific gravity such as polypropylene and polymethylpentene are preferable from the viewpoint of reducing the weight of the insulating material. In particular, polymethylpentene is a crystalline resin having a melting point of 240 ° C., so that high heat resistance can be obtained. preferable.

  Since the polyolefin copolymer does not have an aromatic ring, it is used to satisfy arc extinguishing performance. Specific examples thereof include an ethylene-vinyl alcohol copolymer, an ethylene-vinyl acetate copolymer, and the like, but a high-strength resin such as an ethylene-vinyl alcohol copolymer is preferable from the viewpoint of improving the pressure resistance. .

  Polyamide refers to a polymer compound having an amide bond, and the present invention includes a polyamide copolymer. Polyamide is a high-strength resin and is used to satisfy the pressure strength. Specific examples thereof 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.

  In particular, when polyamide is included, the ability to cool the arc and improve the arc voltage with a gas generated by decomposition due to arc exposure is excellent, and the overcurrent at the time of interrupting a large current can be suppressed to a low level.

  Among the polyamide resins, 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 matrix resin contains nylon 46, it is possible to continue to generate a thermal decomposition gas derived from a resin effective for arc extinguishing, and to obtain an arc extinguishing insulating material molded body excellent in heat resistance.

  The arc-extinguishing insulating material molded body can be molded by adding additives such as a stabilizer, an antioxidant, an oxidation accelerator, an ultraviolet absorber, a plasticizer, a colorant, and a filler, if necessary. .

  As a method for producing the arc extinguishing insulating material molded body, an existing method can be used. For example, injection molding, extrusion molding, hollow molding (blow molding), thermoforming (vacuum or pressure forming), calender molding, laminated molding in which two or more types of sheets and films are stacked or bonded together, Examples include liquid molding, casting, and powder molding.

  The arc extinguishing insulating material molded body may be subjected to post-treatment such as chemical treatment or physical treatment for improving functionality such as surface light resistance improvement and weather resistance improvement. Examples of chemical treatment include chemical treatment, solvent treatment, coupling agent treatment, monomer / polymer coating, and surface grafting. Examples of the physical treatment include ultraviolet irradiation treatment, plasma treatment, and ion beam treatment.

  According to the circuit breaker of the present invention, due to the contribution of the decomposition gas by the arc of the arc extinguishing insulating material molded body installed in the vicinity of the contact point, as a result of the current limiting performance being enhanced, at the time of overcurrent interruption such as the occurrence of an accident, By reducing the energy injected into the circuit breaker itself, it is possible to reduce the burden on the structure of the circuit breaker and to increase the capacity or the size of the circuit breaker.

  In the circuit breaker of the present invention, the arc extinguishing insulating material molded body as described above is installed in the vicinity of the contact point, and the contribution of the decomposition gas of the arc extinguishing insulating material molded body by the arc enhances the current limiting performance, The arc generated between the contacts is stretched and guided to the arc extinguishing plate. As a result, the load on the structure of the circuit breaker is reduced by the reduction of the energy injected into the circuit breaker itself at the time of overcurrent interruption such as the occurrence of an accident.

Examples of the present invention will be described below, but the present invention is not limited thereto.
(Examples 1-2, Comparative Examples 1-2)
Table 1 shows the material composition of the arc-extinguishing insulating material molded bodies of Examples 1-2 and Comparative Examples 1-2. As the matrix resin, polyamide 46 (DSM TS350) was used. As the inorganic filler A, acicular titanium oxide (aluminum hydroxide-treated product: Ishihara Sangyo FTL-110) or wollastonite (SH-800 manufactured by Kinsei Matec) was used. In addition, about acicular titanium oxide and wollastonite, it does not decompose | disassemble at 1500 degrees C or less, and generally the data regarding decomposition | disassembly are not obtained. As the inorganic surface treatment agent, aluminum hydroxide was used, and an arc-extinguishing insulating material molded body was produced using the inorganic filler A surface-treated with the inorganic surface treatment agent. The proportion of the total amount of inorganic machine filler A and inorganic surface treatment agent in the arc extinguishing insulating material molded body was 30% by weight. The amount of the inorganic surface treatment agent added was 1% by weight with respect to the amount of the inorganic filler A.

  The arc extinguishing insulating material molded body is manufactured by heat-kneading the resin shown in Table 1 and the inorganic filler A surface-treated with an inorganic surface treatment agent with a side-feed type resin kneader, and using an extruder to produce pellets. After forming, it was manufactured by injection molding. An arc-extinguishing insulating material molded body having a thickness of 1 mm was installed in the circuit breaker illustrated in FIGS. 3 and 4, and an overload interruption test and a short-circuit interruption test were performed. The contents of the overload interrupt test and the short circuit interrupt test are as follows.

(Overload interruption test)
In this test, a circuit breaker including the arc extinguishing insulating material molded body having the above-described configuration was energized with a current 6 times the rated current in a closed state (for example, 600 A in the case of a 100 A circuit breaker), and the movable contact 4 and the fixed contact 5 are separated so that the contact opening distance L (distance between the movable contact 4 and the fixed contact 5) is 15 to 25 mm, an arc current is generated, and the arc current is interrupted a specified number of times. This is a test that passes with success.

(Short-circuit interruption test)
This test passed in the closed state by passing an excess current of 10 to 100 kA to release the movable contact, generating an arc current, and the success of the specified number of interruptions of this arc current and no breakage. This is a test.

  As test conditions of this example, the overload interruption test passed AC690V / 600A, 12 interruptions, the short circuit interruption test was 440V / 50kA, 3 interruptions were possible, and the arc extinguishing insulating material molded body and The circuit breaker vessel was accepted as having no damage.

  In Examples 1 and 2, the overload test reaches the specified number of interruptions 12 times, the short circuit test also achieves the specified number of interruptions 3 times, and the arc extinguishing insulating material molded body and the breaker housing are damaged. There was no. As a result of observing the surface and cross section of the arc extinguishing insulating material molded body after the overload interruption test of Examples 1 and 2, it was confirmed that the surface exposed to the arc contained a mixture of resin and inorganic filler. did it. On the other hand, in Comparative Examples 1 and 2, either the overload interruption test or the short circuit interruption test could not reach the specified number.

  As a result of observing the arc extinguishing insulating material molded body after the overload interruption test of Comparative Example 1, it was found that wollastonite was exposed on the surface and continuous interruption could not be performed due to lack of resin components. As a result of observing the surface after the overload blocking test of the arc extinguishing insulating material molded body of Comparative Example 2, partially dissolved glass fibers were exposed on the surface. From this, it is considered that continuous shut-off cannot be performed due to a shortage of resin components. Regarding the failure of the short circuit interruption test, it is considered that the soot generated at the time of interruption was deposited on the exposed glass fiber, and it became electrically conductive, resulting in a creeping discharge path, which hindered arc interruption.

  From the above results, since the arc extinguishing insulating material molded body of the present invention includes the needle-like or fibrous inorganic filler A surface-treated with an inorganic surface treatment agent that decomposes at 1500 ° C. or lower, the conventional arc extinguishing It has been found that it has the strength to withstand the interruption of a larger electric capacity than the molded product of insulating material, and is excellent in overload interruption performance and short circuit interruption performance. Moreover, it was shown that the circuit breaker using the arc-extinguishing insulating material molded body of the present invention is excellent in circuit breaking performance.

  Although the embodiments and examples of the present invention have been described as described above, it is also planned from the beginning to appropriately combine the configurations of the above-described embodiments and examples.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  1 movable contact, 2 movable contact, 3 fixed contact, 4 fixed contact, 5 arc-extinguishing insulating material molded body, 6 arc extinguishing plate, 7 notch, 8 arc, 9, 10 terminals, 100 arc extinguishing device, 11 Arc extinguishing side plate, 110 opening / closing mechanism part, 13 handle, 120 trip device part, 14 cover, 15 base, 16 guide groove, 17 end plate, 17a exhaust hole, 18 housing.

Claims (8)

An arc extinguishing material molding used for a circuit breaker,
Inorganic filler A that does not decompose at 1500 ° C. or less, and a matrix resin,
At least a part of the inorganic filler A is coated with an inorganic surface treatment agent that decomposes at 1500 ° C. or less,
An arc-extinguishing insulating material molded body in which the inorganic filler A is needle-like or fibrous, or includes an acicular inorganic filler B different from the inorganic filler A.   The arc-extinguishing insulating material molded article according to claim 1, wherein the inorganic surface treatment agent decomposes at 300 ° C to 1500 ° C. The arc extinguishing insulating material molded article according to claim 1 or 2, wherein the inorganic surface treatment agent is aluminum hydroxide or aluminum oxide hydrate.   The arc-extinguishing insulating material molded body according to any one of claims 1 to 3, wherein the inorganic filler A and the inorganic filler B are acicular titanium oxide.   The arc-extinguishing insulating material molded body according to claim 1 or 2, wherein the inorganic filler A is acicular titanium oxide and the inorganic surface treatment agent is aluminum hydroxide.   The insulating material for arc-extinguishing according to any one of claims 1 to 5, wherein the inorganic filler A has a needle shape with a minor axis length of 0.01 to 5 µm and a major axis length of 0.05 to 50 µm. Molded body.   The arc-extinguishing insulating material molded body according to any one of claims 1 to 6, wherein the matrix resin includes nylon 46.   A stator having a fixed contact, a mover having a movable contact, an opening / closing mechanism for operating the mover, and an arc extinguishing when the fixed contact and the movable contact are separated from each other. A circuit breaker comprising an arc extinguishing device including the arc extinguishing insulating material molded body according to claim 7.

Images