Arc extinguish chamber base of circuit breaker for wiring
阅读说明：本技术 配线用断路器的灭弧室底座 (Arc extinguish chamber base of circuit breaker for wiring ) 是由 姜泰允 赵昱东 姜寿炯 宋宪燮 金汉吉 李建贤 于 2019-01-04 设计创作，主要内容包括：本发明涉及一种配线用断路器的灭弧室底座,更详细而言,涉及一种利用热塑性树脂制造的配线用断路器的灭弧室底座。本发明由于利用芳香族聚酰胺系的热塑性树脂来制造构成配线用断路器的灭弧室底座,因此具有能够提高生产率,实现部件的轻量化,减少部件的生产时间,能够环保以及再利用的效果。此外,具有增加部件寿命的效果。(The present invention relates to an arc-extinguishing chamber base for a circuit breaker for wiring, and more particularly, to an arc-extinguishing chamber base for a circuit breaker for wiring, which is manufactured using a thermoplastic resin. The invention uses aromatic polyamide thermoplastic resin to manufacture the arc extinguish chamber base of the circuit breaker for wiring, thereby having the effects of improving productivity, realizing light weight of components, reducing production time of the components, and being environment-friendly and reusable. In addition, there is an effect of increasing the lifetime of the parts.)
1. An arc-extinguishing chamber base of a circuit breaker for wiring adapted to the circuit breaker for wiring having respective constituent parts provided therein, the circuit breaker for wiring being provided at a part of a circuit so as to break or energize the circuit, the arc-extinguishing chamber base being characterized in that,
the arc chute mount is formed of a thermoplastic resin,
the thermoplastic resin is an Aromatic polyamide (polyphthalal amide) resin having the following chemical formula,
2. the arc chute mount of a circuit breaker for wiring according to claim 1,
the thermoplastic resin contains a PA66(Polyamide resin) material.
3. The arc chute mount of a circuit breaker for wiring according to claim 1 or 2,
the Aromatic polyamide resin contains 30 mol% or more and less than 100 mol% of Aromatic dicarboxylic acid (Aromatic dicarboxylic acid).
4. The arc chute mount of a circuit breaker for wiring according to claim 1 or 2,
the aromatic polyamide resin comprises an aliphatic or alicyclic diamine (diamine) of C4 to C15.
5. The arc chute mount of a circuit breaker for wiring according to claim 1,
a metallic material is included in the arc chute base.
6. The arc chute mount of a circuit breaker for wiring according to claim 1,
the arc extinguishing chamber base further comprises an inorganic filler, a heat stabilizer, an antioxidant, a light stabilizer, a flame retardant and a toner.
7. The arc chute mount of a circuit breaker for wiring according to claim 1,
the arc extinguish chamber base is made of a material which comprises 30-75 wt% of the aromatic polyamide resin, 20-65 wt% of the inorganic filler and 1-50 wt% of the rest materials.
8. The arc chute mount of a circuit breaker for wiring according to claim 1,
the arc extinguishing chamber base contains spherical particles formed of any one of ceramics, glass, and fibers.
Technical Field
The present invention relates to an arc-extinguishing chamber base for a circuit breaker for wiring, and more particularly, to an arc-extinguishing chamber base for a circuit breaker for wiring, which is manufactured using a thermoplastic resin.
Background
Generally, a wiring Circuit Breaker is a Circuit Breaker surrounded by a molded Case (Mold Case) having a rated current of 2500A or less, which is used for protecting an indoor low-voltage Circuit of 600V or less of ac and 250V or less of dc, and is also called a Molded Case Circuit Breaker (MCCB) in american standard NEMA, which is also an international common name.
In korea, a wiring breaker is required to be installed according to power equipment technical standards, internal wiring regulations, and the like, and is a mechanism in which a switching mechanism, a trip device, and the like are integrally assembled in a container of an insulator, and an electric circuit in an energized state is switched by manual or electric operation, thereby automatically breaking the electric circuit in a state of overload, short circuit, and the like.
When an abnormality occurs in a circuit, the wiring breaker prevents damage to wiring and connectors or fire by quickly disconnecting the circuit, and prevents such failures as overload and short-circuit current.
That is, the circuit is opened before a current equal to or higher than the rated current flows and the temperature reaches a dangerous state, and the circuit is instantaneously opened when a large fault current such as a short circuit flows.
When a circuit through which a current flows is broken by the contacts, an arc (a phenomenon in which the atmosphere serving as an insulator is an electric conductor in a plasma state due to voltage breakdown) is generated between the contacts, and the arc increases in proportion to the magnitude of the current.
Since the central temperature of the arc reaches 8000 to 12000 ℃, and the arc has explosive expansion pressure, the contact is melted and consumed, and the insulation is deteriorated or damaged.
In this case, the case of the circuit breaker for wiring plays a role of preventing damage due to such an arc generated at the time of disconnection, and safely extinguishing the arc to protect other components inside the product.
Regarding such a wiring circuit breaker, a material of a case of the wiring circuit breaker, particularly, a material suitable for an arc extinguishing Chamber Base (arcextinggush Chamber Base) is characterized in that Unsaturated polyester (Unsaturated polyester) is used as a main component, a low shrinkage agent is mixed, and a Thickener (thickner) such as magnesium oxide, magnesium hydroxide, or the like is added thereto. The material is used as a solidified material, has excellent electrical stability, mechanical stability, thermal stability, dimensional stability and chemical resistance, and is generally suitable for electric equipment products with limited thermoplastic materials.
According to the production method of such a thermosetting material, Sheet Molding Compound (SMC), Bulk Molding Compound (BMC), or the like is used.
Fig. 1 is a schematic diagram showing a manufacturing process of a BMC used when manufacturing a conventional circuit breaker for wiring, and fig. 2 is a schematic diagram showing a manufacturing process of an SMC used when manufacturing a circuit breaker for wiring.
As shown in fig. 1 and 2, the BMC used in manufacturing a conventional circuit breaker for wiring is manufactured from a thermosetting reinforced plastic mechanical molding material in the form of a block (Bulk) obtained by adding glass fibers as a reinforcing agent to a base material (Matrix) in which an unsaturated polyester resin, a low shrinkage agent, a curing agent, a filler, a release agent, and the like are uniformly mixed in a Kneader (Kneader), and then impregnating the base material with the glass fibers.
The SMC is produced from a thermosetting reinforced plastic mechanical molding material in the form of a Sheet (Sheet) obtained by impregnating glass fibers (1 inch) in a Matrix (Matrix) prepared by uniformly mixing an unsaturated polyester resin, a low shrinkage agent, a curing agent, a filler, a release agent, and the like in a Premixer (premier) and then thermochemically aging the impregnated glass fibers.
Specifically, the wiring breaker uses SMC and BMC materials mainly composed of unsaturated polyester, and these materials contain a curing agent, and therefore, the curing reaction gradually proceeds even at room temperature, and therefore, the wiring breaker cannot be used for a long period of time, and the physical properties thereof vary with the storage time.
In addition, since the Glass Fiber is sensitive to temperature and humidity and has large variation in physical properties, there is a large variation in quality in production in different seasons, and uniform dispersion of the Glass Fiber is limited in the BMC Kneading (crimping) process, so that variation occurs in parts at the time of injection molding of the parts.
Further, since the shelf life of the product is usually six months and is very short, when the wiring breaker is produced using the above-mentioned material, since the product is molded using the thermosetting unsaturated polyester having a long curing time, a long curing time is required after packaging, and a post-treatment process is generated as a Burr (Burr) which is a portion protruding in a band shape, thereby increasing the number of production processes and work processes and increasing the unit cost of parts.
Further, since a thermosetting unsaturated polyester resin which is not recyclable is used as a main material of a circuit breaker for wiring, there is a problem that resource recycling and environmental protection cannot be achieved.
The following two methods are available as the part production method.
Fig. 3 is a structural view of injection molding of parts for producing a conventional wiring breaker, and fig. 4 is a structural view of compression molding of parts for producing a conventional wiring breaker.
As shown in fig. 3 and 4, the SMC and BMC materials manufactured by injection molding have the greatest advantage that the glass fibers having increased strength have very excellent mechanical strength due to their long length (3 to 12mm), but are broken irregularly when injected into the
On the other hand, since compression molding requires a worker to accurately measure and set the mold 40 for molding, the process time is long, the yield is low, and the quality of the product varies depending on the measurement amount, the measurement size, the measurement position, the worker, and the like.
As described above, the conventional circuit breaker for wiring uses a thermosetting resin, and thus requires a long curing time, and causes an after-treatment process due to burrs (Burr), which increases the number of production processes and work processes, resulting in a problem of high unit cost of parts.
Further, since a thermosetting unsaturated polyester resin which is not recyclable is used as a main material of a circuit breaker for wiring, there is a problem that it is difficult to reuse resources and it is not environmentally friendly.
Disclosure of Invention
Problems to be solved by the invention
The present invention has been made to solve the above problems, and an object of the present invention is to provide a circuit breaker for wiring, which is manufactured using a thermoplastic resin.
Technical scheme for solving problems
An arc-extinguishing chamber base for a circuit breaker for wiring according to an embodiment of the present invention is formed of a thermoplastic resin, and the thermoplastic resin is an aromatic polyamide (poly) resin having the following chemical formula.
Here, the thermoplastic resin is characterized by containing a PA66(Polyamide resin) material.
The aromatic polyamide resin is characterized in that the aromatic dicarboxylic acid (aromatic dicarboxylic acid) is 30 mol% or more and less than 100 mol%.
Further, the aromatic polyamide resin is characterized by containing an aliphatic diamine or an alicyclic diamine (diamine) of C4 to C15.
Further, it is characterized in that a metal material is contained in the arc chute base.
Further, the arc extinguishing chamber base further includes an inorganic filler, a heat stabilizer, an antioxidant, a light stabilizer, a flame retardant, and a toner.
The arc-extinguishing chamber base is composed of 30-75 wt% of the aromatic polyamide resin, 20-65 wt% of the inorganic filler, and 1-50 wt% of the remaining material.
The arc extinguishing chamber base further includes spherical particles made of any one of ceramics, glass, and fibers.
Effects of the invention
Since the arc-extinguishing chamber base for the circuit breaker for wiring according to an embodiment of the present invention is manufactured using an aromatic polyamide (polyphthalamide) thermoplastic resin, it is possible to improve productivity, to reduce the weight of parts, to reduce the production time of parts, to increase environmental friendliness, and to reuse the parts.
Further, since the PA66 material is polymerized with the polyphthalamide-based thermoplastic resin and molded, the physical properties (mechanical characteristics) of the material are improved.
In addition, by making the polyphthalamide-based thermoplastic resin composed of 4 to 15 aliphatic carbons in number and the polyphthalamide-based thermoplastic resin composed of 30 to 100 mol% benzene rings, the physical properties (mechanical characteristics) of the circuit breaker for wiring are significantly improved.
In particular, the thermoplastic resin produced by the components as described above increases the part life and reduces the rate of deterioration of physical properties with the passage of time.
Drawings
Fig. 1 is a schematic diagram showing a manufacturing process of a BMC used in manufacturing a conventional wiring breaker.
Fig. 2 is a schematic diagram showing a manufacturing process of an SMC used in manufacturing a conventional circuit breaker for wiring.
Fig. 3 is a sectional view showing an injection molding apparatus used in manufacturing a conventional circuit breaker for wiring.
Fig. 4 is a sectional view showing a compression molding apparatus used in manufacturing a conventional circuit breaker for wiring.
Fig. 5 is a sectional view showing a wiring breaker according to an embodiment of the present invention.
Fig. 6 is a perspective view showing an arc extinguishing chamber base in the wiring circuit breaker according to the embodiment of the present invention.
Fig. 7 is a cross-sectional view showing an arc extinguishing chamber base provided in the circuit breaker for wiring according to the embodiment of the present invention.
Detailed Description
Hereinafter, a wiring breaker according to an embodiment of the present invention will be described in detail with reference to the drawings.
Fig. 5 shows a circuit breaker for wiring according to an embodiment of the present invention, and fig. 6 shows an arc extinguishing chamber base applied to the circuit breaker for wiring according to an embodiment of the present invention.
As shown in fig. 5 and 6, the wiring circuit breaker 100 according to the present invention is provided in a part of a line (circuit), and is activated to switch the line when an overcurrent or a fault current occurs. The wiring breaker 100 is provided with a trip device, and when an abnormality such as an overload or a short circuit occurs in a line, the line is automatically disconnected by activating a switching mechanism, thereby protecting the load and the line.
In this case, the wiring breaker 100 includes: a housing 110; a fixing base 130 fixed to the power supply terminal 120 at one side of the housing 110; a movable table 150 provided to be rotatable by the shaft 140; an arc extinguishing chamber 160 provided around the contact portions 130, 150; an opening and closing mechanism 200 configured to rotate the shaft 140 while a lower link (not shown) is interlocked with an upper link (not shown) connected to the handle 170; a trip mechanism part 300 which turns on the switching mechanism part 200 according to the overcurrent and short-circuit current generated in the line, thereby cutting off the current; and a load terminal 400 connected to the trip mechanism unit 300.
In the circuit breaker 100 for wiring having the above-described structure, when an overload occurring on a line falls within an overcurrent range, heat is generated in the heater 307 provided inside the trip housing 301, causing the bimetal 306 fixed by the rivet to start to bend
As the bimetal 306 is bent, the gap between the adjusting screw 308 disposed at the upper portion and the trip bar 309 is narrowed, and finally the adjusting screw 308 pushes the trip bar 309, so that the trip bar 309 is rotated counterclockwise.
At this time, the ejector (not shown) restricted by the trip bar 309 is released, and the switch mechanism 200 is activated, so that the circuit breaker 100 is opened.
Fig. 6 shows an arc chute mount 500 in the wiring circuit breaker 100, which is applied to an embodiment of the present invention. The arc chute base 500 is formed of injection molding or compression molding. The arc chamber base 500 is provided with a fixed base 130, a movable base 150, a shaft 140, an arc chamber 160, and the like, and the switching mechanism portion 200 is provided at the upper portion.
The arc extinguishing chamber base 500 of the wiring circuit breaker 100 according to the present invention configured as described above is formed of a thermoplastic resin. The thermoplastic resin may be an Aromatic polyamide (polyphthalamide) resin having the following chemical formula.
The aromatic polyamide resin contains a repeating unit of the above chemical formula. Here, 4< m <15, 50< n <1000, and are integers, respectively.
The Aromatic polyamide resin preferably contains a benzene ring (benzene ring) and is composed of 30 mol% or more and less than 100 mol% of Aromatic dicarboxylic acid (Aromatic dicarboxylic acid).
Polyamide (PA) materials have been widely used as insulating materials for electric power equipment products, and Polyamide (Polyamide) materials have been widely used as PA66 and PA6 materials for Polyamide (Polyamide) products, because they are excellent in electrical insulation, mechanical strength, heat resistance, abrasion resistance, flame retardancy, and moldability.
In addition, Polyamide (polyamine) is mainly used for cases of circuit breakers and switch products of low-voltage power equipment, but it is difficult to replace curable materials (melting point: 220 degree for PA6, melting point: 260 degree for PA66) because of its poor heat resistance (melting point)
Therefore, in the present invention, an aromatic polyamide, i.e., polyphthalamide (PPA) is used in forming the case 110. Aromatic polyamide (polyphthalamide) materials have a molecular structure similar to that of Polyamide (PA), but have an Aromatic (benzene ring) structure unlike general PA, and therefore have high rigidity and mechanical strength, have characteristics of maintaining high rigidity under high temperature conditions (Tm: 290 ℃ to 325 ℃, Tg: 90 ℃ to 140 ℃), and have high heat resistance, low moisture absorption rate, dimensional stability, low distortion, chemical resistance, and high retention of physical properties to the external environment.
The material used in the present invention has an Aromatic (Aromatic) ratio of 30 to 100 mol% and an Aliphatic (Aliphatic) carbon chain on both sides of an Amide (Amide) group in the range of 4 to 15.
In the case of a mixed alloy with another material which is not a polymer, the Aromatic (Aromatic) ratio in the total may be 30 to 100 mol% in terms of mol%.
The following table is a comparison table of materials using SMC and ppa (polyphthal amide) according to the present invention when manufacturing the arc-extinguishing chamber base 500.
[ Table 1]
SMC
PPA
Density (g/cm)3)
1.73
1.65
Tensile Strength (MPa)
39.54
196.11
Tensile modulus (MPa)
9862
20017
Elongation (elongation) (%)
0.48
1.72
Flexural Strength (MPa)
72.94
305.39
Flexural modulus (flexural modulus) (MPa)
9520
17829
Impact Strength (KJ/m)2)
11.02
8.64
As shown in the above table, in the circuit breaker 100 for wiring according to the present invention, the arc extinguishing chamber chassis 500 is formed of a polyphthalamide-based thermoplastic resin, and therefore, mechanical properties such as tensile strength and tensile modulus are improved as compared with the conventional circuit breaker 100 for wiring manufactured by SMC.
The material of the arc extinguishing chamber base 500 includes an aromatic polyamide resin (a), an inorganic filler (B), a heat stabilizer (C), an antioxidant (D), a light stabilizer (E), a flame retardant (F), a toner (G), and the like.
Here, the inorganic filler (B) is carbon fiber (carbon fiber), glass fiber (glass fiber), boron fiber, carbon black, clay (clay), kaolin (kaolin), talc (talc), mica (mika), calcium carbonate, aluminum hydroxide, or the like, and may be used by coating a coupling agent (coupling agent) in order to improve interfacial adhesion with the thermoplastic resin.
The material composition range is preferably composed of 30 to 75 wt% of the aromatic polyamide resin, 20 to 65 wt% of the inorganic filler (glass fiber), and 1 to 50 wt% of the remaining material.
The results of testing the material of the arc extinguishing chamber base 500 using the test piece (test piece) are shown in tables 2 and 3 below. In the following examples and comparative examples, the types and weight ratios of the inorganic filler (B), the heat stabilizer (C), the antioxidant (D), the light stabilizer (E), the flame retardant (F), and the toner (G) were the same, with only the capacity of the aromatic polyamide resin (a) being changed. Here, the total weight ratio excluding the aromatic polyamide resin a was 55%.
The aromatic polyamide resin (a) is not an aromatic polyamide resin having an aromatic ring in the main chain, but is used in consideration of the flowability in the molding step, the injection moldability, and the like of the polymerized PA66 material.
Differentiation of "aromatic polyamide resins" in this test
(A1) Polyamide resin (Polyamide resin) (PA 6T): an aromatic polyamide resin having an aromatic ring in the main chain, which is produced by polycondensation of Terephthalic acid (Terephthalic acid) and Hexamethylenediamine (Hexamethylenediamine), namely PA6T, was used.
(A2) Polyamide resin (Polyamide resin) (PA 4T): an aromatic polyamide resin having an aromatic ring in the main chain, which is produced by polycondensation of Terephthalic acid (Terephthalic acid) and tetramethylene diamine (tetramethylene diamine), namely PA4T, was used.
(A3) Polyamide resin (Polyamide resin) (PA 66): PA66, which is produced by polycondensation of Adipic acid (Adipic acid) and Hexamethylenediamine (Hexamethylenediamine), is used.
In table 2 below, the ratio (mixing ratio) of B + C + D + E + F + G represents the ratio of wt% with respect to the total 100%, and a represents the ratio between the aromatic polyamide resins (base resins) on a 100% weight basis in a state other than B + C + D + E + F + G.
Each of the components was added in accordance with the content shown in table 2 below to produce a biaxially melt-extruded Pellet (Pellet) form, and the pellets thus obtained were dried at a temperature of 100 ℃ for 6 hours or more, and then a test piece for physical property evaluation (ISO standard test piece) was produced by an injection molding machine.
[ Table 2]
[ Table 3]
The initial physical properties were measured after preparing test pieces for evaluation of physical properties at 25 ℃, relative humidity: physical properties were measured after 48 hours of pretreatment under 50% conditions, and the results of the physical property measurements after the test were determined after 648 hours of standing at 180 ℃.
Here, the component life was measured by an accelerated test conducted by a Gear imaging over at 160 ℃, 180 ℃, and 200 ℃ for 2400 hours, 648 hours, and 480 hours, respectively, according to UL746-b (RTI test), and then the same pretreatment as the pretreatment method was conducted, and based on the measured physical properties, the time (year) for the physical properties of tensile strength to decrease to 40Mpa at 100 ℃ which is the actual service temperature condition of the arc extinguishing chamber BASE of the circuit breaker for wiring (MCCBAEC BASE) was calculated by Arrhenius equation (Arrhenius equation). The 40Mpa tensile strength benchmark is the minimum physical property required for the tensile strength of the part when the product is used.
As described above, the arc extinguishing chamber base 500 may be formed by applying a polyphthalamide-based thermoplastic resin to which a material such as PA66 is polymerized.
Among the physical properties in the table, in terms of initial physical properties, if the content of Glass fiber (Glass fiber), reinforcing agent, or the like is increased, the supporting force between the polymers (Polymer) becomes high, and thus the mechanical strength is improved.
The mechanical properties of the test pieces behave similarly with the same content of PA66, PA6, PPA or inorganic filler.
The polyphthalamide-based thermoplastic resin is characterized by a low rate of deterioration of physical properties with the passage of time in a high-temperature use environment, and therefore can be used in place of a curable material. That is, maintaining the properties of the PPA physical properties over the initial physical properties is more important for arc chute mount 500 under long term use conditions. As shown in the table, specifically, the component life of the example of the present invention was more excellent than that of the comparative example. In addition, mechanical properties such as tensile strength, impact strength, and dielectric strength were also shown at the same or higher levels as in the comparative examples. Also, from the physical properties after the test, it was also shown that the rate of decrease of the comparative initial physical properties was lower than that of the comparative examples.
As described above, according to the present invention, the arc extinguishing chamber chassis 500 constituting the wiring circuit breaker 100 is manufactured using the polyphthalamide-based thermoplastic resin, so that productivity can be improved, weight reduction of parts can be achieved, the production time of the parts can be reduced, and environmental protection and recycling can be achieved.
Further, since the PA66 material is polymerized with a polyphthalamide-based thermoplastic resin and molded, the physical properties (mechanical characteristics) of the material are improved.
In addition, the physical properties (mechanical properties) of the circuit breaker for wiring are significantly improved by making the number of aliphatic carbons in the polyphthalamide-based thermoplastic resin be 4 to 15 and making the benzene ring of the polyphthalamide-based thermoplastic resin be 30 to 100 mol%.
In particular, the thermoplastic resin having the above-described structure increases the life of the parts and reduces the rate of deterioration of physical properties with the passage of time.
Another embodiment of an arc chute mount 500 is shown in figure 7. In this embodiment, the spherical particles 510 are contained in the resin forming the arc chute base 500. Such spherical particles 501 may be formed of ceramic, glass, fiber, or the like. The ball particles 501 may be mixed prior to injection into the plastic injection molding process. This further improves the mechanical properties such as pressure resistance, impact resistance, and heat resistance.