JPS58181246A - Switch - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to suppressing pressure within a container of a switch. Note that the term "switch" as used in the present invention particularly refers to a container such as a circuit breaker, current limiter, or electromagnetic switch, which normally causes arcing within a small container.

In the following, a circuit breaker will be explained as an example.

Figures 1 to 3 are cross-sectional views showing conventional circuit breakers.
Each shows a different operating state.

(1) is a cover, (2) is a base, and the cover (1) and base (2) constitute a container (3). (4) is a fixed contact, and a fixed contact (6) is attached to one end of the fixed conductor (5).
), and the other end is a terminal portion to be connected to an external conductor (not shown). (7) is a movable contact, and has a movable contact (9) at one end of its movable conductor (8) opposite to the fixed contact (6). 00 is a movable contact device, (1
1J is fixed to the crossbar (2) by a movable arm and is configured to be opened and closed at each pole interval. (To) is an arc-extinguishing state, and the arc-extinguishing plate α is held by the side plate 00. αYU is a toggle link mechanism, consisting of an upper link αη and a lower linter. One end of the upper link θη is attached to Fredol Q9),
In addition, the other end is attached to one end of the lower link H, respectively.
It is connected by cutting 1). The other end of the lower link (l) is connected to the movable arm αυ of the movable contact device RQO.

2'4 is a tilting operation handle, (c) is an operating spring, which connects the shaft of the toggle link mechanism clQ and the above operation handle (manufactured by Co., Ltd.)
is stretched between. Q4) and (b) are thermal and electromagnetic trip mechanisms, respectively, and when activated, the trip bar (c) is rotated counterclockwise by bimetal (2) and movable iron core 271, respectively.

Numeral 4 is a latch whose one end is locked to the trip bar and the other end is locked to the fredle θ9j.

If the operating handle (2-) is turned to the closed position with the Freddle (19) locked in the latch @ go, the toggle link mechanism (I
I extends and pivots l) is locked to the fredle θ9), and the movable contact (9) is joined to the fixed contact (6). This state is shown in FIG. Next, when the operation handle (22) is tilted to the open position, the toggle link mechanism is bent and the movable contact (9)
is opened from the fixed contact (6), and the movable arm Qll is locked between the fredle shafts. This state is shown in FIG. Furthermore, if an overcurrent flows through the circuit in the closed state shown in Fig. 1,
The thermal trip mechanism (241 or electromagnetic trip mechanism) is activated to release the engagement between the fredle α9 and the latch 9), and the fredle (19) rotates clockwise around the fredle shaft, causing the stopper to close. It is locked to the shaft @l).

Since the connection point between the fredle (19) and the upper link αη crosses the line of action on the operating spring, the toggle link mechanism α is bent by the spring force of the operating spring (4), causing the crossbar (
2), automatic shutoff is performed in conjunction with each pole. This state is shown in FIG.

Next, the behavior of the arc that occurs when the circuit breaker interrupts the current will be explained.

Now, when the movable contact (9) and the fixed contact (6) are in contact, the power is transferred from the power source side to the fixed conductor (5).
), fixed contact (6), movable contact (9) and movable conductor (
8) and is sequentially supplied to the load side. In this state, when a large current such as a short-circuit current flows through this circuit, the movable contact (9) is separated from the fixed contact (6) as described above. At this time, the fixed and movable contacts (6),
(9), an arc O'A is generated between the fixed and movable contacts (61, (9)), and an arc voltage is generated between the fixed and movable contacts (61, (9). This arc voltage is generated from the fixed contact (6) to the movable contact (9) increases as the separation distance increases, and at the same time, the arc (34) is attracted and elongated by the magnetic force in the direction of the arc-extinguishing plate QΦ, so it further rises.In this way,
The arc current reaches the current zero point, extinguishes the arc, and completes the interruption. However, although this injected beautiful arc energy eventually becomes thermal energy and completely escapes from the container, it temporarily increases the temperature of the gas inside the limited container, and will cause the gas pressure to rise rapidly.

As a result, the insulation inside the circuit breaker may deteriorate, and the amount of sparks emitted to the outside of the circuit breaker may increase, leading to a power supply short-circuit accident or destruction of the circuit breaker body.

Next, we will discuss the energy consumption mechanism of the arc, which was the basis for creating this invention.

FIG. 4 shows an arc A generated between contacts (4) and (7). In the figure, T indicates the flow of thermal energy conducted from the arc A to the contact and escapes, and m indicates the flow of energy of metal particles escaping from the arc space. %R indicates the flow of energy due to light escaping from the arc space. In FIG. 4, the energy injected into the Ark person is mostly consumed by the three energy flows mentioned above, T, m, and R. Of this, heat escape T to the electrode is minute, and most of the energy is carried away by m and R. Now, in the past, in the energy consumption mechanism of Ark humans, m in the diagram was overwhelming, and ordinary energy was almost ignored, but recent research by the inventors has revealed that ordinary energy, In other words, the energy consumption by light is approximately 70% of the energy injected into arc A.
It has come to light that she is so beautiful that she even reaches the height of tai.

That is, the consumption of energy injected into arc A can be analyzed as follows.

Pw = V ・I = PK 10Pth 10PRPK=
mv"+m -Cp -'r However, Pw: Instantaneous injection energy V: Arc voltage ■: Current V・■: Instantaneous electric energy injected into the arc PK:
Instantaneous energy consumption carried away by metal particles 2 m V2' m Instantaneous energy consumption carried away when g metal particles fly away at speed V m-Cp-T: constant pressure specific heat Cp gas (metal particle gas) at temperature T Instantaneous energy consumption carried away when escaping pth: Instantaneous energy consumption that escapes from the arc space to the contact by heat conduction PR Instantaneous energy consumption radiated from the arc by two lights The above consumption is the contact It varies depending on the shape and arc length, but for arcs of 10 to 20 mm, each PK
= 10~20chi, Pth 25th section, PR=75~85
I am in charge.

Next, Figure 5 shows the situation when the arc is confined in a container. When arc A is confined in container (3), container (3)
The inner space is filled with metal particles and becomes hot. In particular, the above-mentioned state is strong in the gas space Q around the arc positive column A (the space Q indicated by diagonal lines in the figure). Now, the light emitted from the arc A is emitted from the arc positive column A and is sent to the container (3).
It is irradiated and reflected from the wall. The reflected light is scattered, passes through the high-temperature space filled with metal particles again, and is irradiated onto the wall surface again. This process is repeated until the amount of light becomes zero. The path of light during this time is shown in the figure from Ra→h→
What is Re-+ indicated?

In the above process, the light emitted from arc A is consumed at the following two points.

(1) Absorption at the wall surface (2) Absorption by the arc space and surrounding (high temperature) gas space, that is, absorption by the gas space, and the light emitted from the arc ranges from the far ultraviolet below 2000A to the far infrared above 1μm. It consists of a continuous spectrum and a line spectrum over all wavelength ranges. Even if the surface of a typical container wall is black,
It only has the ability to absorb light in the range of about 00A to 5500A, and in other ranges it only partially absorbs and reflects most of the light. However, absorption in the arc space and surrounding high temperature gas space is as follows.

When a gas space of length L having a uniform composition and temperature is irradiated with light of wavelength λ, the amount of light absorbed by the gas space can be calculated as follows.

Ia = Ae −n −Lfin −
=---・(1)■a Absorbed energy by mini gas Ae: Absorption probability Iin: Irradiated light energy n: Particle density L: Optical path length through which light passes. However, equation (1) is the absorbed energy for a specific wavelength λ. Indicate quantity. M is the absorption probability for a specific wavelength λ and is a function of wavelength λ, gas temperature, and particle type.

Regarding equation (1), according to the teachings of quantum mechanics, the absorption coefficient M has the largest value for a gas that is in the same state as the light source gas that emits light (that is, the type of particles and temperature are the same) for both continuous and line spectra. will have the following. That is, the light emitted from the arc space is absorbed most by the arc space and the surrounding gas space.

In equation (1), the amount of absorbed energy Ia of light is proportional to the optical path length. As shown in Figure 5, when the light from the arc space is reflected by the wall surface, L in equation (1) increases by the number of reflections, and the light is absorbed in the high temperature part of the arc space. The amount of light energy used will increase.

This means that the energy of the light emitted by the arc A is eventually absorbed by the gas in the container (3), thereby increasing the temperature of the gas and the pressure of the gas.

Therefore, the premise of this invention is to use a specific material to effectively absorb the light energy, which reaches about 70% of the energy injected into the arc. fibers, nets, and highly porous materials with an apparent porosity of 35% or more that effectively absorb the light emitted by the arc at specific locations that receive the energy of the light.
By selectively arranging a species or two or more species,
It absorbs a large amount of light inside the container to lower the temperature of the gas space, thereby lowering the pressure.

The above-mentioned fibers are selected from inorganic materials, metals, composite materials, woven materials, non-woven fabrics, etc., but since they are installed in a space exposed to high-temperature arcs, they must have thermal strength.

In addition to inorganic threads, metals, composite materials, etc., the mesh may also be selected from multilayered MB wire alloy meshes, knitted wires, and the like.

This net also needs to have thermal strength.

Among the materials for the fibers and nets mentioned above, ceramics, carbon, asbestos, etc. are suitable for inorganic systems, and P for metals.
E, Cu is most suitable, and those plated with Zn, Ni, etc. are also applicable.

Porous materials are generally materials with a large number of pores within a solid structure, and exist in a wide range of materials such as metals, inorganic systems, and organic materials. One type is sintered and solidified at the contact points between solid particles, and the other type is mainly composed of pores and the partition walls forming the pores are made of solid material. In this invention, the term "material" refers to the original material before being processed into a shape, and can be further classified into materials in which gaps between particles exist as pores, and materials in which gaps between particles and pores within particles exist. They can be divided into those that share pores and those that contain foamable pores. It can also be roughly divided into those that have air permeability and water permeability, and those that have independent pores and are not breathable.

The shape of the above-mentioned pores is very complicated and is roughly classified into open pores and closed pores, and the structure is expressed by pore volume or porosity, pore diameter and pore diameter distribution, specific surface area, etc.

Porosity is the ratio of the volume of all open and closed pores contained in a porous material to the total volume of the material (bulk volume), that is, the true porosity is expressed as a percentage, and the measurement method is is determined by a liquid or gas substitution method, an absorption method, etc., but as a simple method, it is calculated as follows, as defined in JISR2624, Method for Measuring Specific Gravity and Porosity of Fireproof and Insulating Bricks.

In addition, the ratio of the volume of the open pores to the total volume (bulk volume) of the material, that is, the apparent porosity expressed as a percentage, is defined as the JISR 2205 method for measuring the apparent porosity, absorption rate, and specific gravity of firebrick. As defined, it is calculated as follows.

Note that the apparent porosity is also referred to as the effective porosity.

Saturated water weight - Dry weight Apparent single pore x 100 cm Saturated water weight - Weight in water Although the interfacial gap ranges from several λ (angstroms) to the maximum, it is generally defined as the average value of the distribution.

In porous materials, the shape, size, and distribution of pores can be measured using a microscope or mercury intrusion method.

In general, it is preferable to use a microscope directly in order to accurately understand the complicated shape and distribution of pores.

The BET method is often used to measure the specific surface area, which is determined by using adsorption crosstalk at each temperature of various adsorbed gases.
In particular, nitrogen gas is often used.

Next, we will explain the absorption of light energy by a specific material and the resulting drop in gas pressure, which is the premise of this invention.
This will be explained using an example of an inorganic highly porous material.

FIG. 6 is a perspective view showing the inorganic highly porous material, and FIG. 7 is a partially enlarged sectional view of FIG. 6. In the figure, (to) indicates a highly porous inorganic material, and (goods) indicates an opening leading to the surface of the inorganic material. The pore diameter of the open pores is from several μ to several R1
It shows a distribution of various sizes up to 1.

Now, as shown by R in Figure 7, when light enters this porous material and enters the opening, the light is reflected by the wall of the inorganic material, and the pores of the material are reflected. It undergoes multiple reflections inside the wall, and is finally absorbed 100% by the wall surface. In other words, the light that enters the pores is directly absorbed by the surface of the inorganic material and becomes heat within the pores.

The eighth panel shows a curve diagram of the pressure change inside the model container when the apparent porosity of the inorganic highly porous material is changed in a model container in which the inorganic highly porous material is placed. In FIG. 8, the horizontal axis is the apparent porosity, and the vertical axis is the pressure normalized to 1 when the inner wall of the container is made of metal such as Cu, Fe, or AI.

The experimental conditions were as follows: AgW contacts were installed at a constant gap of 10 degrees in a cubic hermetic container with sides of 10 cIrL, and an arc of a sinusoidal current with a peak of 10 KA was generated for 8 mS (milliseconds). Measuring internal pressure.

The inorganic highly porous material used in the above examples is a porous ceramic made by molding and sintering cordierite ceramic raw material by adding a combustible or foaming agent to make it porous. The apparent porosity of the porous material with a pore size range of 10-300μ is 20 and 30μ.

35chi, 40chi, 45chi, 50chi, 60chi, 70chi, 8
Various samples measuring 50 mm x 50 mm x 3 mm were used and were placed on the wall of the container so as to cover 50 inches of the surface area of the inner surface of the container.

Regarding the pore diameter, the issues are the average pore diameter, which slightly exceeds the wavelength range of the absorbed light, and the ratio of the pores to the surface, that is, the specific surface area of the pores. Further, in terms of absorption of light within the pores, deep pores are effective, and continuous pores are preferable. Since the light generated from the arc in a switch is distributed in the range of several hundred A to 1000 A (1 μm), it is suitable to have an average pore diameter that slightly exceeds this, that is, from several thousand feet to several thousand μm, and to occupy the surface area. A highly porous material in which the area of the pores has an apparent porosity of 35% or more is suitable for absorbing the light emitted by the arc. In particular, the upper limit of pore size is 1
The larger the specific surface area of the pores, the greater the effect. In experiments, it was confirmed that an average pore diameter of 5 μm to 11111 μm showed good absorption characteristics for the light emitted by Arc A. The material is glass and the average pore diameter is 5μ.
, 20μ was observed to absorb light emitted by Ark well.

As can be seen from the characteristic curve a in Figure 8, the pores of the inorganic highly porous material absorb light energy and have the effect of reducing the pressure inside the switch.This is because the apparent porosity of the porous material is It becomes larger as the porosity increases, and becomes particularly noticeable when the porosity exceeds 35 inches, and the effect was confirmed in the range up to 85 inches. Further increases in porosity require corresponding increases in the thickness of the highly porous material.

However, the appearance of porous materials is related to the porosity and mechanical strength; when the porosity becomes large, it becomes brittle, has low thermal conductivity, and is easily melted by high heat, and when the porosity is small, The effect of reducing pressure inside the switch is weak. Therefore, in practical terms, the apparent appearance of a porous material is a highly porous material with a porosity in the range of 40 to 70%. This can be inferred from the above explanation regarding absorption.

Some conventional switches use inorganic materials, but their primary purpose is to protect organic containers from arcing, and their characteristics include arc resistance, longevity,
Heat conduction, mechanical strength, insulation, and countermeasures against carbonization are required, and inorganic materials that meet these requirements are necessarily oriented toward densification and have different purposes, and their apparent porosity is 2
It is around 0chi.

Highly porous materials include inorganic, metallic, and organic materials, among which inorganic materials are characterized as insulators and high melting point materials. These two properties make it ideal as a material to be installed inside the switch container, and since it is an electrical insulator, it will not have a negative effect on shutoff, and it will not melt when exposed to high temperatures or cause gas It is ideal as a pressure suppressing material because it does not emit any gas.

Porous inorganic materials include porous ceramics, anti-corrosion materials, glass, hardened cement, and the like, and any of them can be used to reduce the pressure of gas in the switch. Note that organic porous materials have problems with heat resistance and gas generation, and metal porous materials have problems with insulation and withstand voltage, so the places where they can be used are limited.

By the way, when the current is small or in a switch without an arc-extinguishing plate, even if one electric contact is provided with an arc runner, the magnetic driving force acting on the arc is small, so the arc generated at the contact is It tended to stagnate.

This invention was made to solve the above problems, and by providing a panel made of the above-mentioned specific material in the vicinity of the arc runner of an electric contact provided with an arc runner, the internal pressure can be reduced. The purpose of the present invention is to provide a switch that can suppress the noise and improve the interrupting performance.

An embodiment of the present invention will be described below with reference to the drawings.

9(A) and 9(B) show an example of a circuit breaker to which the switch according to the present invention is applied, and FIGS.
The same parts as those in the figure are given the same reference numerals and the explanation will be omitted.

In the figure, the arc runner is provided at the tip of the fixed conductor (5). On the back side of this arc runner (C), a panel OQ made of an inorganic highly porous material is provided evenly parallel to the arc runner. It protrudes laterally from both side edges (35a) to η, so that it can receive sufficient arc light.

Next, the effects of the above configuration will be described.

Arc 02 that occurred between contacts (6) and (9) when opening
Among the light energy, the light directed toward the casting side of the panel (G) made of an inorganic highly porous material is quickly absorbed by the panel edge, so that a temperature rise in the space X on the panel side is unlikely to occur. On the other hand, the space Y on the opposite side of the panel installation space
(7) is an isothermal combination Q+ in Figure 10.

Q! , it is thought that the temperature distribution will be as shown by Qa. The space Y on the opposite side of the panel installation space X is.

Since the high temperature region is spread over a wide area, dissociation and ionization in the air and in the container material are likely to occur. As a result, this can become a source of local pressure, so from the perspective of arc @2, the arc ba is caused by the pressure difference between the space X on the side where the panel-〇 is installed and the space Y on the opposite side. Move to the installation side. that time.

Since the panel plate made of inorganic porous material is provided close to the fixed conductor (5) side, the arc @ odor is reliably transferred to the conductive arc runner and extended. Breaking properties can be improved.

By the way, in the above embodiment, the panel (2) is apparently made of an inorganic highly porous material with a porosity of 35% or more, but it may be made of a porous material other than inorganic material, or it may be made of a porous material other than an inorganic material. In addition to being able to be composed of fibers or nets instead of the material, it is also possible to be composed of a composite material of two or more of fibers, nets, and porous materials having the above-mentioned specific porosity.

As described above, the present invention suppresses internal pressure by providing a panel made of a specific material capable of absorbing arc light energy in parallel to and close to the arc runner provided on one of the electrical contacts. Moreover, it can contribute to improving the breaker performance.

[Brief explanation of the drawing]

1-3 are cross-sectional views of conventional circuit breakers, each showing different operating conditions. Figure 4 is an explanatory diagram showing how an arc occurs between contacts. Figure 5 is an explanatory diagram showing how an arc occurs between contacts in a container. Figure 6 shows an inorganic highly porous cable material. Fig. 7 is a partially enlarged cross-sectional view of Fig. 6, Fig. 8 is a curve diagram showing the change in pressure inside the container with respect to the apparent porosity when an arc is generated, and Fig. 9 (A) is a partial enlarged sectional view of Fig. 6. FIG. 9(B) is a sectional view showing an example of a circuit breaker to which the switch according to the invention is applied (Al B
-B line sectional view, FIG. 10 is an explanatory diagram of the temperature distribution between the contacts. (3)...Container, (4), (7)...Electric contact, (51, (8)...Conductor, (6), (9)...
... Contact, (32... Arc, (C)... Arc runner, (35a)... Image side edge, (G)... Panel,
G7)...Lateral. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Makoto Kuzuno (1 other person) (c) Figure 1 Figure 2 Figure 3 z □ Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 (B) Figure 10

Claims (4)

[Claims] (1), comprising at least one pair of electrical contacts which are composed of a conductor and a contact fixed to a conductor, one of which has an arc runner and which operates to open and close, and a container for storing these electrical contacts; A panel that receives the light energy of the arc generated when the electrical contact opens is placed on the back side of the arc runner, and is attached to both sides of the arc runner.
The fibers, net, and appearance are made of porous material with a porosity of 35 cm or more.
A switch characterized in that the above-mentioned panel is made of a seed or a composite material of two or more types. (2) The panel is made of an inorganic highly porous material, and the inorganic highly porous material has an apparent porosity of 4.
The switch according to claim 1, which has a diameter of 0 to 70 inches. (3) The switch 0 according to claim 2, wherein the inorganic highly porous material is selected from porous ceramics, refractories, glass, and hardened cement. (4) The switch according to claim 2 or 3, wherein the inorganic highly porous material has an average pore diameter of several thousand amps to several thousand μm.