JPS58181241A - 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" used in the present invention particularly refers to a circuit breaker, a current limiter, an electromagnetic switch, etc., which generates an arc within a container, usually a small container.

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

Figures 1 to 8 are cross-sectional views showing conventional circuit breakers.
Each one shows a different operating status gold.

(1) is a cover, (2) is a pace, and the cover (1) and base 12) constitute the entire container (3). (4) is a fixed contact, and one end of its fixed conductor (51) has a fixing liquid (((
6), and the other end serves as a terminal portion to be connected to an external conductor (not shown). +7) is a movable contact,
A fixed connection is made to one end of the movable conductor (8)! (It has a movable contact, holding ('1) opposite to 61. ad is a movable contact device, (11) is a movable arm, and the cross is fixed at -(12+). Each pole opens and closes at the same time. It is configured as follows. (
13) is an arc extinguishing chamber, in which an arc extinguishing plate (14) is held by a side plate 00. θ6 is a toggle link mechanism, and the upper link θ
It consists of No and the lower link 019. Upper link θη
One end is for Fredol α9), and the other end is for Lower Link (+8
Axis f211 at one end of + respectively] 6! m). The other end of the lower link (I) is connected to the movable arm (11) of the movable contact device 00. ．．
It is stretched between the leg υ of the toggle link mechanism 0■ and the operation handle (A). (c) and (c) are non-moving and electromagnetic tripping mechanisms, respectively, and when activated, the eli lip bar @ is rotated counterclockwise to the bimetal (c) and the movable iron core, respectively. The handle is a latch whose one end rests on the trip bar (C) and the other end engages with the fredle (19).

When the operating handle (A) is tilted to the closed position with the fredle (19) locked to the latch handle, the toggle link mechanism (the hill extends and the shaft 6!L) is locked to the fredle (19), and the movable contact (9) is joined to the fixed contact (6). This state is shown in FIG. Next, when the operation handle (A) is tilted to the fully open position, the toggle link mechanism (1) is bent and the movable contact (9) is opened.
) is opened and separated from the fixed contact (6), and the movable arm (11) comes to a stop at the Freddle. This state is shown in FIG.

The shunting mechanism (c) operates and the engagement between the fredle (19) and the latch is released, and the fredle α9) rotates clockwise around the entire center of the fredle shaft (to) and is locked to the stopper shaft e1. Ru.

Fredol α9) and above link 0? ) crosses the line of action of the actuating spring (c), the glu link mechanism θφ is bent by the spring force of the actuating spring, and the cross bar 02 (
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) in order to be supplied to the load side. In this state, if a large current such as a short circuit current flows through this circuit, As mentioned above, all the movable contacts (9) are separated from the fixed contacts (6). At this time, the fixed and movable contacts (6), (
9) One arc c is generated between the fixed and movable contacts (61 + ('l1). An arc voltage is generated between the fixed contact, g (61
) rises as the separation distance of ) increases, and at the same time, the arc ( ) is attracted by the magnetic force in the direction of the arc-extinguishing plate 0<, and therefore rises further. In this way, is the arc current at the current zero point? The arc is extinguished and the interruption is completed. However, this huge amount of arc energy that is injected eventually turns into thermal energy and completely escapes from the container, but only transiently increases the temperature of the gas inside the slicing device and This will cause the gas pressure to rise rapidly.

This has led to deterioration of the insulation inside the circuit breaker, an increase in the amount of sparks emitted to the outside of the circuit breaker, which has led to power supply short-circuit accidents and destruction of the circuit breaker itself.

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 occurring between contact (4) and +71. In the figure, T indicates the flow of thermal energy conducted from the arc A to the contactor and escapes, n1m indicates the flow of energy of metal particles escaping from the arc space, and R indicates the flow of energy due to light escaping from the arc space. Fourth
In the figure, the energy injected into arc A is largely dissipated by the three energy flows mentioned above, T+ 111+ R. Of this, heat escape to the electrodes TV′1Iil+ is small, and most of the energy is m and R
It will be taken away. Conventionally, in the energy consumption mechanism of arc A, m in the diagram was overwhelming, and the energy of R was almost ignored, but recent research by the inventors has revealed that the energy of R That is, it has been found that the energy consumption by light is so enormous that it reaches about 70% of the energy injected into the arc A.

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

Pw=V-■=PK+Pth+PR PK=r-hnV"10m-CI)" However, Pw: Instantaneous injected energy■ = Arc voltage■ = Current V, I: Instantaneous electric energy PK injected into the arc
: Instantaneous energy consumption taken away by metal particles -1-m v ” : Instantaneous energy consumption nl when metal particles fly away at speed V, Cp -T : Gas with constant pressure specific heat Cp (metal particle gas) Instantaneous energy consumption that is carried away when escapes at temperature T Pth: Instantaneous energy consumption that escapes from the arc space to the contact by heat conduction PR Instantaneous energy consumption that is directly radiated from the arc due to light The above consumption The amount varies depending on the contact shape and arc length.
=10~20%, Pth=5%, PR=75~
It is 85 chi.

Next, the situation when the arc A is confined in the container (3) is shown in Fig. 5. When the arc A is confined in the container (3), the space inside the container (3) 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). 6. The light from the arc positive column is irradiated onto the arc, and this process is repeated until the total amount of light becomes zero. During this time,
RB -P R1)-p R(-+Rd
It is shown in

In the above process, the consumption of light emitted from arc A is 02 points.

(1) Absorption on the wall surface (2) Absorption by the arc space and surrounding (high temperature) gas space, that is, absorption by the gas space and light emitted from the arc ranges from far ultraviolet light below 2000X to far infrared light above 1μlη. It consists of a continuous spectrum and a line spectrum over a wavelength range of . For example, even if the surface of a typical container wall is black,
It only has the ability to absorb light in the range of about 000A 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 with a uniform composition and temperature of length L is irradiated with a light sound of wavelength λ, the absorption 1 of light by the gas space is as follows ↓
It can be calculated as follows.

Ia""Ae'll'Lengineering
---- (1) Engineering a: Absorption energy by gas Ae: Absorption probability ■in: Light energy to irradiate n Two-particle density L: Optical path length through which light passes. However, (Equation 11 is the absorption energy for a specific wavelength λ The quantity is shown. Ae is the absorption probability for a specific wave important person,
It is a function of wavelength λ, gas l crystallinity, and particle type.

Regarding equation (1), if we follow the teachings of quantum mechanics, the absorber g
For both continuous and line spectra, i and A have the largest values 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). 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 of light a 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. By selectively arranging one or more of fibers, nets, and highly porous materials that effectively absorb the light emitted by the arc at specific positions that receive the light energy of the arc, the light inside the container can be reduced. By absorbing a large amount, the temperature of the gas space is lowered, thereby reducing the total pressure.

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

Further, as the mesh, in addition to inorganic materials, metals 2, composite materials, etc., the mesh may be selected from multi-layered fine wire meshes, mesh 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 F for metals.
e+ Cu is optimal, and zn+ Nt or the like plated is 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 of solid particles, and the other type is composed mainly of pores and the partition wall forming the key metal is a solid material. In this invention, the term "raw material" refers to a material that has not yet been processed into a shape and has not yet been processed into a shape.

Further classification can be divided into those in which the gaps between particles exist as pores, those in which the gaps between particles and the pores within the particles are all shared, and those in which foamable pores are included inside. 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 complex and can be broadly 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 entire 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 displacement method, an absorption method, etc., but as a simple method, it is calculated as follows, as defined in the method for measuring the specific gravity and porosity of fireproof and insulating bricks in J.E.C. SR2614.

In addition, the ratio of the open pore volume to the total volume (bulk volume) of all materials, that is, the total apparent porosity expressed as a fraction, is the apparent porosity of J-K5R2205 firebrick,
If we focus on the definition of the method of measuring absorption rate P and specific gravity, they are calculated as follows.

Note that porosity is also referred to as effective porosity.

Pore diameter can be determined from the measured values of pore volume and specific surface area, and ranges from those close to the size of atoms and ions to the interfacial gaps between particles, ranging from several angstroms (angstroms) to several angstroms, but generally, Defined as the mean value of the distribution. In porous materials, the shape, size, and distribution of pores can be completely measured using a microscope or mercury intrusion method. Generally, in order to accurately understand the shape and distribution of complicated pores, it is preferable to use a visual inspection bowl directly.

The BET method is often used to measure the specific surface area, which is determined using the adsorption contour lines at each temperature for 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 inorganic highly porous material as an example.

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, ■ indicates a highly porous inorganic material, and (b) indicates an opening leading to the surface of the inorganic material. The pore diameters of the open pores (c) show a variety of sizes ranging from several microns to several IIj.

Now, as shown by R in Figure 7, when light enters this porous material (to) and enters the opening (b), the light hits the inorganic wall and is reflected, and the It undergoes multiple reflections inside the hole, and eventually 100 pieces of light are absorbed by the wall. That is, the light incident on the opening (b) is directly absorbed by the surface of the inorganic substance, and becomes heat within the pore.

FIG. 8 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 normalized as the total pressure of 1 when the inner wall of the container is made of metal such as CLb'ea A1. As for the experimental conditions, −side 1
AgW contacts are installed at a constant gap of 10 in a cubic hermetic container of 0 crn, and a sinusoidal current arc f of 8 m5 (milliseconds) with a peak of 10 KA is generated, and the pressure inside the container generated by the energy at this time is measured. .

The inorganic highly porous material used in the above examples is a porous ceramic made by molding and sintering a cordiphyte ceramic raw material using a method such as adding a combustible or foaming agent to make it fully porous. Pore size range: 10-800μ) The apparent porosity of the porous material is 20cm.

80th grade, 85th grade, 40th grade, 45th grade, 50%, 60th grade 0
%, 80%, 85%, 50y x 50m1J
Is this all the various samples of l+×81Ut used? It was placed on the wall of the container to cover 50 inches of the surface area of the inner surface of the container.

Regarding the pore diameter, the average pore diameter slightly exceeds the entire wavelength range of the absorbed light, and the proportion of the surface occupied by the pores (that is, the specific surface area of the pores) is a problem. Further, in terms of absorption of light within the pores, deep pores are effective, and continuous pores are preferable.

The light generated from the arc in the switch is several hundred λ to 1000X
(1μm), so it slightly exceeds this,
In other words, pores with an average pore diameter of several thousand λ to several thousand μm are suitable, and the area of the pores on the surface has an apparent porosity of 8.
A highly porous material with a diameter of 5 or more is suitable for absorbing the light emitted by the arc A. In particular, the upper limit of the pore diameter is in the range of 1000 μm or less, and the larger the specific surface area of the pores, the more effective it is.

In experiments, it was confirmed that an average pore diameter of 5 μm to 1 μm exhibited excellent absorption characteristics for the light emitted by Arc A. Furthermore, it was observed that glass materials with average pore diameters of 5 μm and 20 μm absorb light and sound emitted by Arc A well.

As can be seen from the characteristic curve a in Figure 8, the pores of the inorganic highly porous material absorb all of the light energy and have the effect of lowering the pressure inside the switch. It becomes larger as the porosity increases, and becomes particularly noticeable when the porosity is 35% or more, and the effect was confirmed in the range up to 85 cm. Further increases in porosity require corresponding increases in the total thickness of the highly porous material.

However, the appearance of a porous material depends on the relationship between its porosity and mechanical strength.2 If the porosity increases, it becomes brittle, has lower thermal conductivity, and is more likely to melt due to high heat; The effect of reducing pressure inside the switch is weak. Therefore, in practical terms, a highly porous material with an apparent porosity of 40 to 7 (1%) is optimal.

The characteristic trends shown in FIG. 8 apply to inorganic porous materials in general, and this can be inferred from the above explanation regarding light absorption.

Some conventional switches use inorganic materials, but their purpose is primarily to protect organic containers from arc A, and their characteristics include arc resistance, service life,
Heat conduction, mechanical strength, insulation, and countermeasures against carbonization are required, and inorganic materials that meet these requirements are necessarily oriented towards densification and have different purposes, and their appearance is that of pores. The rate is 2
It is around 0%.

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.Since it is an electrical insulator, it will not have a negative effect on shutoff, and will not melt even if exposed to high temperatures. Since it does not emit gas, it is ideal as a pressure suppressing material.

Porous inorganic materials include porous ceramics, refractories, 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 pressure resistance, so the places where they can be used are limited.

By the way, in order to effectively absorb all of the light energy from the arc generated between the contacts, it is conceivable to provide a vertical wall made of the above-mentioned specific material, for example, an inorganic highly porous material, near the contacts.

However, although this method is effective only for suppressing the internal pressure, it does not actively drive the arc.
In the case where there is no such thing, there remains some concern about the interruption performance.

This invention was made in view of the above circumstances, and by providing a first vertical wall made of a heat sublimable organic substance and a second vertical wall made of the above-mentioned light energy absorbing material at specific positions, the internal pressure can be reduced. The overall purpose is to provide a switch which can reduce the amount of electricity and, in particular, improve the breaking capacity and breaking properties.

An embodiment of this invention will be explained below with reference to the drawings.

FIG. 9 shows an example of a circuit breaker to which all the switches according to the present invention are applied, and the same parts as in FIGS. 1 to 8 are given the same reference numerals, and the explanation thereof will be omitted.

In the same figure, on both sides in the width direction of the electric contact 44L t7), as shown in FIG.
(It also serves as a support for the arc extinguishing plate (14) at the position facing 91.
c. First standing wall (2).

(to) is provided. These first standing walls (to), 0
→ is composed of heat-sublimable organic substances, such as Teflon. (To) and (G) are the above electric contact (4), f7
The second standing wall is parallel to the direction in which the current flows and is arranged in series with the first standing wall, and is made of the above-mentioned light energy absorbing material, for example, with an apparent porosity of 85.
%IJ is composed of an inorganic highly porous material. The second vertical walls (7), (to) are bonded to the container (3) like the arc extinguishing plate (14) or this embodiment.

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

Since the light energy from the contact point ftut (to the arc generated between 91) is absorbed by the second vertical walls (to), (to), the internal pressure is suppressed.

Especially as the current increases, the first vertical wall (to), (to)
The space between them becomes high temperature due to the heat of the arc, and the pressure rises as the standing walls (c) and (c) made of thermally sublimable organic matter release greedy steam. On the other hand, when the arc is driven into the space between the second vertical wall (7), the light energy from the arc (7) in that space is transferred to the second vertical wall (7) made of an inorganic highly porous material. 7).

Since this space is not absorbed by the gas in that area, the humidity and pressure are lower than if there were no second vertical walls. During this time, the pressure in the space between the first vertical walls (to) and (to) becomes higher than the pressure in the space between the first vertical walls (to) and (to). As a result, the space length between the first vertical walls is increased. If the arc is extended, the arc voltage will increase, and the breaking capacity and performance will improve.

By the way, the first vertical wall 05 can be selected from Teflon as well as other organic materials such as polyacetal resin and acrylic resin.

The heat-sublimable organic substance mentioned here is desirably one that emits at least more steam than the container (3) itself, since the container (3) itself is made of an organic material and increases the steam rate.

Further, in the above embodiment, the second vertical wall OI (to) is made of an inorganic highly porous material with an apparent porosity of 85 cm or more, but it may be made of a porous material other than inorganic material. ,
-Furthermore, instead of the porous material, it can be constructed of fibers or nets, or it can be constructed of a composite material of two or more of the above-mentioned fibers, nets, and porous materials having the above-mentioned specific porosity.

As described above, this invention provides a first
By arranging the vertical wall and the second vertical wall made of a specific material capable of absorbing the optical energy of the arc in a specific positional relationship, it is possible to completely suppress the internal pressure, and in particular to reduce the breaking capacity and breaking performance at high currents. It is possible to provide a switch that can be improved.

[Brief explanation of the drawing]

1 to 8 are cross-sectional views of a conventional circuit breaker, showing 70 different operating conditions. Figure 4 is an explanatory diagram showing how an arc occurs between contacts. Figure 6 is an explanatory diagram showing how an arc occurs between contacts in a container. Figure 6 is a perspective view showing an inorganic highly porous material. 7 is a partial enlarged 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. A cross-sectional view showing an example of a circuit breaker to which a switch metal is applied, FIG. 10 is a cross-sectional view taken along the line X--X in FIG. 9. (3)... Container, (4), (7)... Electric contact,
fil, (8)...4 groups, (6), (9)...
Contact point, ■...Arc, ■...First standing wall, (to)
...Second standing wall. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Makoto Kuzuno - (1 other person) Figure 1 Figure 2 F

Claims (3)

[Claims] (1) at least one pair of electrical contacts that are configured of a conductor and a contact fixed thereto and that operate to open and close;
a container for storing the N perfect contact; the first vertical wall is made of a thermally sublimable organic material and receives the light energy of the arc generated when the electrical contact is opened; A second standing wall is provided on both sides in the width direction of the child, facing the contact point, and is made of a composite material of one or more of fibers, nets, and porous materials, and is arranged in the direction of the total current flow. A switch characterized in that it is arranged in parallel and in series with the first vertical wall. (2) The switch according to claim 1, wherein the second vertical wall is made of an inorganic highly porous material, and the inorganic highly porous material has an apparent porosity of 40 cm to 70%. . (3) The inorganic highly porous material is selected from porous ceramics, refractories, glass, and cement hardened bodies.
The switch according to claim 2 or 8, which has a diameter of 0 μm.