JPS58181240A - 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, all examples of circuit breakers will be described.

Figures 1 to 8 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) make up the entire container (3). (4) is a fixed contact, and one end of the fixed conductor f51 has a fixed contact (6
), and the other end serves as a terminal portion to be connected to an external conductor (not shown). (7) is a movable contact, which has a fixed contact at one end of its movable conductor (8), and a movable contact (9) opposite to li (61). Qd is a movable contact device, and (11) is a movable contact. The child arm is fixed to the crossbar (121) and is configured to open and close when each pole is spaced (131).
In the arc extinguishing chamber, an arc extinguishing plate α is held by a side plate (15). (1t is a toggle link mechanism, consisting of uplink 07) and lower link (kuni).One end of upper link 0η is attached to Freddle θ, and the other end is attached to one end of lower link H with axes -1 and an. The other end of the lower link 0 is connected to the movable arm (Il) of the movable contact device 00.
connected to l.

(A) is the tilting operation handle, 0 is the operating spring, and the axis of the toggle link mechanism 0■? ! A suspension type is installed between n and the above-mentioned operating handle. (c), the handles are thermal and electromagnetic tripping mechanisms, and when activated, the bimetallic (e) and movable iron core (c), respectively, are activated.
is designed to rotate counterclockwise. One end of the wire is secured to the trip above - (to), and the other end is attached to the fredle (to).
A latch holds it in place.

When the operating handle (A) is tilted to the closing position with the Freddle (19) resting on the latch handle, the toggle link mechanism (1~
is extended, the shaft eD is locked to the fredle (19), and the movable contact (9) is connected to the fixed contact (fi+). This state is shown in Fig. 1. Next, the operating handle (c) is moved to the open position. When the toggle link mechanism is bent, the movable contact (9) is opened from the fully fixed contact (6), and the movable arm (11) is locked to the fredle shaft (to). This is Figure 2.

In addition, if an overcurrent flows through the circuit in the closed state shown in Fig. 1, the thermal tripping mechanism (c) or electromagnetic tripping mechanism (c) operates to lock the fredle (19) and the latch handle. When released, the Freddle rotates clockwise around the entire center of the Freddle shaft and is locked to the stopper shaft Cl.

Since the connection point between the fredle θ9) and the uplink 0η crosses the line of action of the actuating spring (2), the toggle link mechanism Od is bent by the spring force of the actuating spring holder, causing the crossbar (I2
), each pole is linked to perform automatic shutoff. 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, g (61) are in contact, the power is transferred from the power source to the fixed conductor (5), the fixed contact (6), the movable contact (9), and the movable conductor. It is supplied to the load side via (8) sequentially.In this state, if a large current such as a short circuit current flows through this circuit,
As described above, the movable contact (9) is separated from the fixed contact (6). At this time, the fixed and movable contacts (Ill.
, (91), and an arc voltage is generated between the fixed and movable contacts (6) and (9). This arc voltage is generated between the fixed contact (6) and the movable contact (9). )
As the separation distance increases, the arc rises, and at the same time, the arc further rises because it is attracted by the magnetic force in the direction of the arc extinguishing plate (141) and elongates.In this way, The arc current reaches the current zero point and the arc is completely extinguished.
Shatr? is completed. However, this huge amount of arc energy injected eventually becomes thermal energy and completely escapes from the container, but it temporarily increases the temperature of the gas inside the container, which eventually leads to This will cause the total gas pressure to rise rapidly.

This raised the risk of deterioration of the insulation inside the circuit breaker, an increase in the amount of sparks emitted to the outside of the circuit breaker, resulting in a power supply short-circuit accident 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 is a diagram showing an arc formed between contacts (4) and f7). In the figure, T indicates the flow of thermal energy conducted from the arc A to the contact and escapes, m 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. There is. In FIG. 4, the energy injected into the arc A is almost consumed by the three energy flows ns T* m, H mentioned above. Of this, the amount of heat T that escapes to the electrode is minute, and the energy of the university is carried away by m and RVc. Now, conventionally, in the energy consumption mechanism of arc A, m in the figure is overwhelming, and R
The energy of R is almost ignored, but recent research by the inventors has shown that the energy of R, that is, the consumption of energy by light, is so huge that it reaches about 70 times the energy injected into arc A. It has now been clarified that the consumption of energy injected into the arc AIC can be analyzed as follows.

Pw = V-1 - PK 10 P j 11 + PR However, Pw: Instantaneous injected energy V: Arc voltage: Current: Current: Instantaneous electrical energy PK = injected into the arc
The instantaneous energy consumption carried away by metal particles is the highest! -mv': Instantaneous energy consumption m-Cp-TH constant pressure ratio #! Instantaneous energy consumption taken away when cp gas (metal particle gas) escapes at temperature T pth: Instantaneous energy consumption that escapes from the arc space to the contact by heat conduction PR: Direct radiation from the arc by light Instantaneous energy consumption The above consumption varies depending on the contact shape and arc length, but is 10 to 2 (for a 1 m arc, PK =
10-20%, Pth=5chi, PR=75-85chi.

Next, Fig. 5 shows the situation when the arc A is confined in the entire container +3). When all Ark people are 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). Now, the light emitted by the arc A is emitted from the arc positive column A, and is irradiated onto the wall of the container (3) and reflected. 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 R in the diagram.
a→R1)-eRC-PRd.

In the above process, the consumption of light emitted from the Ark is as follows. It is copper.

(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 light emitted from the arc ranges from far ultraviolet light below 2000X to far infrared light above 11 tm. It consists of a continuous spectrum and a line spectrum over a wavelength range of . The wall surface of a typical container has the ability to absorb light only in the black area, and in other areas, it only absorbs some of the light and reflects most of it. However, absorption occurs in the arc space and surrounding high temperature gas space.

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

■a= Ae-n-LIin −+
-・-・<11 engineering a: Absorption energy by gas Ae: Absorption probability engineering in: Irradiated light energy n: Particle density L: Optical path length through which light passes. However, equation (1) is the absorption energy for a specific wavelength λ. Indicate quantity. 80 is the absorption probability for a specific wavelength λ,
It is a function of wavelength input, gas humidity, and particle type.

Regarding equation (1), according to the teachings of quantum mechanics, the absorption coefficient Ae 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 solid 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 of light a is proportional to the optical path length. As shown in Figure 5, when light from the arc space is reflected by the wall surface, L in equation (1) increases by the number of reflections, and is absorbed in the high temperature part of the arc space. This results in an increase in the amount of light energy that is intercepted.

This is the amount of energy of the light emitted by arc A, the container (
3) It is absorbed by the gas inside, which means that the temperature of the gas increases and the pressure of the gas increases.

Therefore, the premise of this invention is to use a specific material to effectively absorb the light energy, which reaches about 70q6 of the energy injected into the arc, and to remove the arc within the switch container. By selectively arranging one or more of fibers, nets, and highly porous materials that can effectively absorb the light sound emitted by the arc at specific positions that receive light energy, the light inside the container can be absorbed. Humidity in the gas space by absorbing a large amount? It lowers the pressure, thereby lowering the pressure.

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

- Also, as the mesh, in addition to inorganic materials, metals, composite materials, etc., fine wire wire meshes stacked in multiple layers, wire mesh wires, etc. can also be selected.

In the case of this net as well, it is necessary to have something that increases thermal strength.

Among the materials for the fibers and nets mentioned above, ceramics, carbon, asbestos, etc. are suitable for inorganic materials, and
e+Cu is optimal, and fully plated zn+Nl is also applicable.

A porous material is generally a material that has many pores within its solid structure, and exists in a wide range of materials such as metals, inorganic systems, and organic materials. One type is sintered and solidified at the points of contact between 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 the original material before shape processing, which is not shaped 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 shared, and those in which the pores are contained within the foamable key metal. 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 classified into large 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 measured by defining the true porosity as 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, expressed as a percentage. The method is based on 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 specific gravity and porosity of fireproof and insulating bricks of J.K. 8R2614.

In addition, the ratio of the open pore volume to the total volume (bulk volume) of all materials, that is, the apparent porosity expressed as a percentage, is the apparent porosity of R2205 firebrick from J.
As defined in the method for measuring absorption rate and specific gravity, it is calculated as follows.

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

Is pore diameter the pore volume? O: Obtained from the measured value of the specific surface area, it ranges from a few angstroms to several angstroms, ranging from the size of an atom or ion to the interfacial gap between particles.In general, the average value of the distribution is defined. For porous materials, the shape, size, and distribution of pores can be measured using a microscope method or mercury intrusion method.In general, in order to accurately understand the complicated shape and distribution of pores, It is direct and preferable to use w4 mirror.

To measure the specific surface area, the BET method is often used, which is determined by using the absorption coefficient (M M k) at each temperature of various adsorbed gases, and nitrogen gas is especially used.

Next, we will explain the premise of this invention, the absorption of light energy by a specific material and the pattern of gas pressure drop due to 70.
#i A detailed description will be given using a porous material with a deep red structure as an example.

FIG. 6 is a perspective view showing the entire inorganic highly porous material, and FIG. 7 is a partially enlarged sectional view of FIG. 6. In the same figure, ■ indicates a highly porous inorganic material, and 轡 indicates an opening that leads to the surface of the inorganic material. The pore diameters of the open pores (b) vary in size from a few microns to a few microns.

Now, as shown by R in Figure 7, when light enters this porous material (c) and enters the aperture (b), the light hits the wall of the inorganic material and is reflected. The multiple reflections inside the hole eventually result in 100% absorption by the wall surface. In other words, the light incident on the opening (2) is directly absorbed by the surface of the inorganic material 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 and highly porous material is changed when all the inorganic and highly porous materials are placed in the model container. 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+AI. The experimental conditions were as follows: The device was installed at a constant gap of 1 ocrn on the negative side, and an arc of a sinusoidal current with a peak of 10 KA was generated for 8 mB (milliseconds), and the pressure inside the container generated by the energy at this time was measured.

The inorganic highly porous material used in the above example is a porous ceramic material made of cordierite material that is fully flammable or molded and sintered using a method such as adding a foaming agent to make it porous, with an average pore size. The apparent porosity of the porous material ranges from 10 to 800 μm.

80chi, 85chi, 40chi, 45chi, 50chi, 60chi, 7
0 inch, 80 inch, 85%, 60 inch x 50111J
Various samples of X8- were used and 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 entire 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. The light emitted from the arc in the switch is distributed over several hundred X to 10,000λ (1 μm), so it is suitable to have an average pore diameter that slightly exceeds this, that is, from several thousand f to several 1000 μm, and to occupy the surface area. A highly porous material whose pore area has an apparent porosity of 85 cm 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 μ to 1 wJ exhibited excellent absorption characteristics for light emitted by an arc. In addition, the material is glass and the average pore size is 5μ, 2
It was observed that a material with a diameter of 0μ absorbs light 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 light energy and have the effect of reducing the pressure inside the switch. It becomes larger as the porosity increases, and becomes especially noticeable when the porosity is 85 or higher, and the effect was confirmed in the range up to 85. Further increases in porosity require corresponding increases in the total thickness of the highly porous material.

However, the appearance of porous materials is related to the porosity and mechanical strength.If the porosity becomes large, it becomes brittle, has low thermal conductivity, and is easily melted by high heat, and if the porosity is small, the switch The effect of internal decompression is weak. Therefore, in practical terms, the most suitable porous material is a highly porous material with a porosity in the range of 40 to 70 inches.

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 legal measures are required, and inorganic materials that meet these requirements are necessarily composed of dense materials, but have different purposes, and their apparent porosity 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 electrically insulating material, it will not have a negative effect on shutoff, and it will not melt even when exposed to sunlight. It is ideal as a pressure suppressing material because it does not burn or completely blacken the gas.

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 withstand voltage, so the places where they can be used are limited.

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

However, although this method has a remarkable effect on suppressing the internal pressure, it tends to reduce the internal pressure excessively, so it can be used in cases where the breaking capacity is small with a small current, or where there is no magnetic drive against the arc, making it easy for the arc to remain in the contact. This results in a problem of poor arc extinguishing performance at the zero current point.

This invention was made in view of the above circumstances, and is made of the above-mentioned specific material, and includes a first standing wall disposed in the vicinity (a first standing wall disposed in the vicinity) and an organic substance disposed in series on the first standing wall. It is an object of the present invention to provide a switch which can suppress internal pressure and also ensure improved arc extinguishing performance by combining with a second vertical wall consisting of.

Hereinafter, one embodiment of the present invention will be described according to the gold (2) side.

Fig. 9 shows an example of a circuit breaker to which the switch according to the present invention is applied, and the same parts as Figs. 1 to 8 are shown.
The same reference numerals are used to omit the explanation.

In the same figure, there is a first vertical wall c119. (to) at a position opposite to the electric contact (4L) (on both sides of the force in the width direction, as shown in Fig. 10), and ((6), (9)). It is provided.

These vertical walls are made of the above-mentioned light energy absorbing material, such as an inorganic highly porous material with an apparent porosity of 85 cm or more. (to) and (to) are parallel to the current flow direction of the electric contacts (4) and +7), and are arranged in series with the first vertical wall (to).
It is a standing wall made of heat-sublimable organic material like Teflon.

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

A part of the light energy emitted by the arc (to) generated between contact point (B) ), (to), and is not absorbed by the arc (to), suppressing the rise in humidity near the contacts (6) and (9), and by extension suppressing the inner core. will be done.

When the current reaches the zero point, the light energy near the contact points (6) and (9) becomes weaker, and the light energy near the first vertical wall (to), (
7), the pressure becomes low, and if this becomes excessive, the arc tends to stay at the contacts (6) and (9). However, the part where the second standing walls (to) and (to) made of heat-sublimable organic matter are arranged is
The standing wall (to), the generation of steam from 0I maintains the Senriki in a high state. As a result, due to the pressure difference, the second vertical wall (to), c! A flow is generated from the portion where the contact point m1 (9) is disposed toward the vicinity of the contact point m1 (9). As a result, the arc (near the current zero point) is expanded at once, and the arc voltage temporarily increases, resulting in improved arc extinguishing performance.

FIG. 11 shows another embodiment, in which a second vertical wall (2), (to) made of a heat-sublimable organic substance is provided in front of the first vertical wall (2), (to). This embodiment also has the same effects as the above embodiment. Of course, the first standing wall (2
) and the second standing wall (7) are not limited to being on the same straight line.

By the way, in each of the above embodiments, the first standing wall (end).

(To) Although it is apparently made of an inorganic highly porous material with a porosity of 85 cm or more, it may be made of a porous material other than an inorganic material, or it may be made of fibers or nets instead of the porous material. In addition, it is also possible to use a composite material of two or more of fibers, nets, and porous materials having the above-mentioned specific porosity.

In addition to Teflon, the second vertical walls (2) and (to) may be made of polyacetal resin, acrylic resin, or the like.

Note that the second vertical walls (to) and (to) are similar to container (3) since container +3) is also made of organic material.
It is preferable to use a material that emits steam rather than the organic materials that make up the material.

As described above, this invention utilizes arc light energy
By arranging the first vertical wall made of a specific absorptive material and the second vertical wall made of a heat-sublimable organic material in a specific positional relationship, it is possible to suppress internal pressure, and also to improve arc-extinguishing properties. Therefore, it is possible to provide a switch that can achieve all improvements.

[Brief explanation of the drawing]

FIGS. 1-8 are cross-sectional views of conventional circuit breakers, each showing different operating conditions. Fig. 4 is an explanatory diagram showing how an arc is generated between contacts, Fig. 5 is an explanatory diagram showing how an arc is generated between contacts in an if device, and Fig. 6 is an explanatory diagram showing how an arc is generated between contacts in an if device. 7 is a partially enlarged sectional view of FIG. 6, FIG. 8 is a curve diagram showing the change in the internal royal power of the container with respect to the apparent porosity when the arc is fully generated, and FIG. 9 is a partial enlarged sectional view of FIG. A sectional view showing an example of a circuit breaker to which the entire switch according to the invention is applied, FIG. 10 is a sectional view taken along the line X-X of FIG. 9, and FIG. 11 is a plan view of the main part showing another embodiment of the invention. FIG. (3)...Container, (4L m...Electric contact, r5
1, (8)...Conductor, till 1 (9)...
・Tangential 1st, work...arc, (to)...first standing wall,
(To)...Second standing wall. Note that the arrows in the figures indicate the same or corresponding parts. Agent Makoto Kuzuno - Outside 1 Valley Figure 6 Figure 7 Figure 8 Figure 20 30 40 50 60 70 80 90↑
Kei 1 (Ding no Ki Hokujyo [°l.] Figure 9 Figure 10

Claims (4)

[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;
and a container for storing the electrical contact, which is made of a composite material of one or more of fibers, nets, and porous materials, and is configured to prevent an arc generated when the electrical contact opens. A first vertical wall that receives light energy is provided on at least one side of the electrical contact in the width direction, facing the contact, and a second vertical wall made of a heat sublimable organic substance is provided parallel to the direction of current flow. and are arranged in series in the direction of current flow n with respect to the first vertical wall. (2) The switch according to claim 1, wherein the first vertical wall is made of an inorganic highly porous material, and the apparent porosity of the inorganic highly porous material is 40 to 70 cm. . (3) The switch 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 8, wherein the inorganic highly porous material has an average pore diameter of several thousand amps to several thousand μm.