JPS5935338A - 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 switch referred to in this invention particularly refers to a container such as a circuit breaker, a current limiter, an electromagnetic switch, etc., which usually generates an arc within a small container.

The present invention will be explained below using a circuit breaker as an example.

1 to 8 are cross-sectional views of conventional circuits and faults, each showing a different operating state.

(υ is the cover, (2) is the base, and the cover (1) and the base (2) constitute the container (3). (4) is the fixed contact, which is the fixed conductor (5), and 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 movable conductor (8) and a movable contact (9) facing the fixed contact (6) at one end thereof. (10 is a movable contactor device, 0η is fixed to the cross spar plate with a movable arm so that each pole can be opened and closed at the same time. CI 1 is an arc extinguishing chamber, and an arc extinguishing plate 0 is connected to the side plate (to). 06 is a toggle link mechanism consisting of an upper link Q71 and a lower link a8. One end of the upper link (17)
The shaft f is attached to the trowel, and the other end is attached to one end of the lower link (to).
Connected by J&υ. The other end of the lower link (119 is connected to the above-mentioned movable contactor device (10 no Machi mover arm 0)). (2) is a raised-type operating handle, and the lower link is an operating spring and is a toggle link mechanism oQ. - (2) is a thermal and electromagnetic trip mechanism, respectively, and when activated, the trip bar ( 2) Rotate counterclockwise at °C.

4 is a latch whose one end is locked to the trip bar (c) and the other end is locked to the cradle QIIJ. While it is locked in the fredl four-way latch (2), press the operating handle (2).
) is in the closing position, the toggle link mechanism QQ is extended, the shaft (2) is locked to the fredle (9), and the movable contact (9) is joined to the fixed contact (6). This state is shown in FIG.

Next, when the operating handle (A) is turned to the closed position 6+, the toggle link mechanism αQ is bent and the movable contact (9) is moved to the fixed contact (
6) The movable arm aυ is opened and rotated, and the fredl shaft (7
). This state is shown in FIG. Additionally, if an overcurrent flows through the circuit in the closed state shown in Figure 1, the trip bar (E) is activated by the thermal tripping mechanism (C) or the electromagnetic tripping mechanism (C), causing the Freddle 01 and the latch to close. The engagement is released, the Freddle music rotates clockwise around the Freddle shaft, and is locked to the stopper shaft 6v. At this time, since the connection point between the Freddle bend and the upper link 071 crosses the line of action of the above-mentioned actuation spring, the actuation is caused by the spring force of the spring to bend the C toggle link mechanism QQ, and the crossbar σ
4, each pole is interlocked to perform automatic shutoff. This state is shown in FIG.

Next, the behavior of the arc generated 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 supply side to the fixed conductor (5).
, fixed contact t (6), movable contact side and movable conductor (8)
is supplied to the load side via the In this state 1
When a large current such as a short circuit current flows through this circuit, the movable contact (9) is moved one distance away from the fixed contact (6) as described above. At this time, the fixed and movable contacts (6) and (97
An arc ■ occurs between the fixed and 'rrJ moving contacts (6
) and (9), an arc voltage is generated between them. This arc voltage is applied to the opening 1 of the movable contact (9) from the fixed contact (6).
As the σ ratio distance increases, it rises, and at the same time, the arc is drawn and elongated by the magnetic force in the direction of the arc-extinguishing plate Q4, so it further rises. In this way, the arc current reaches m current zero point, extinguishes the arc, and completes the interruption. However, this injected significant arc energy will eventually either escape completely out of the vessel in the form of thermal energy, or transiently increase the temperature of the gas within the confined vessel, causing will cause the gas pressure to rise rapidly. This resulted in serious drawbacks such as deterioration of the insulation inside the circuit breaker, power supply short-circuit accidents due to an increase in the number of sparks emitted to the outside of the circuit breaker, 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 generated between the contacts (4) and (7). In the figure, 'r' represents the journey of thermal energy escaping from the arc by conduction through one contact, m represents the flow of energy of metal particles escaping from the direction of the arc, and R represents the flow of energy due to light escaping from the arc space. There is C. FIG. 8: The injected energy is almost consumed by the above three energy flows, Tlm and R.

Of this, the amount of heat T that escapes to the electrode is minute, and most of the energy is carried away by m and R by °C.

C1 Conventionally, in the mechanism of arc energy consumption, m in the figure is the pressure 4M EF+, and R(7
) energy has been largely ignored, or recent research by the inventors has shown that the energy of R, that is, the consumption of energy by light, is approximately 70% of the energy injected into the arc.
It has now been discovered that the dog is a kA dog with a kA of up to %.

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

Pw=V-1=Pk+PLh+Pir PK=-! -mv"10m-Cp -T2 However, PW: Instantaneous injection energy V: Arc voltage I2 Current V-I: Instantaneous electrical energy P injected into the arc
K: Instantaneous energy consumption 'mv' carried away by metal particles: Instantaneous energy consumption when mg metal particles wait for a ship to fly away at speed V m-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 electrode by heat conduction PR: Instantaneous energy consumption that is radiated directly from the arc by light The above consumption The amount varies depending on the electrode shape and arc length, but for arcs of 10 to 2QIIIN, PK
= 10~2096. , Pth = 5%PR = 7
It is 5-85%.

Next, Figure 6 shows the situation when the arc is confined in one container. When the arc is confined in the container, the space inside the container is filled with electrode metal and becomes hot.

In particular, the above-mentioned state is strong in the surrounding gas space +1A3Q of the arc positive column A (space Q indicated by diagonal lines in the figure). °C.

The light emitted by the arc 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 electrode particles again, and is irradiated onto the wall surface again. This process is repeated until the photodamage is reduced to zero.

The path of light in this period is shown in the figure as Ra-+ Rb->Rc
−p Shown at Rd °C.

In the above process, the light emitted from the 'C1 arc is consumed in the following two ways.

(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.Also, the light emitted from the arc ranges from far ultraviolet light below 2000X to far infrared light above 1 μm. 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 400X to 5500X.
In other ranges, only a portion is absorbed and a large portion is reflected. However, absorption in the arc space and surrounding high temperature gas space is as follows.

When a gas space with a uniform length and temperature is irradiated with human light of four wavelengths, the absorption of light by the gas space can be calculated as follows.

Ia −A°n°LI+n...
・・・・・・・・・・・・(1) Ia: Depends on the gas. Energy harvesting key A: Absorption probability fin: Irradiated light energy n: Particle density L: Optical path length through which light passes. However, (IJ formula is , shows the absorbed energy salt for a specific wave target. A is the absorption probability for a specific wave target, and is a function of the wavelength target, gas temperature, and particle type.

(Concerning the υ equation, according to quantum mechanics teaching 1, the absorption coefficient A is the largest value for dregs in the same state as the light source gas that emits light (i.e., 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 absorption energy of °C1 light -1a, the light I
Compare the colors according to the RX length. As shown in Fig. 5, when the light from the arc space is reflected at the desired point...j, the value in equation (1) increases by the number of reflections, and in the high temperature part of the arc space, As the amount of light energy absorbed increases
This will happen.

In other words, the energy of the light emitted by the arc is eventually absorbed by the gas in the container, which causes the temperature of the gas to decrease.
(is rising, and the pressure of the gas is rising.

Therefore, the premise of this invention is that a highly porous material is used to effectively deflect and absorb the light energy, which reaches approximately 70% of the energy injected into the arc. By distributing a highly porous material that effectively absorbs the light emitted by the arc in the space that receives the energy of the arc light, the light inside the container is evenly absorbed and the gas level is increased. It lowers the temperature between the two, thereby lowering the pressure.

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 threads, and organic materials. One type is sintered and solidified at the contact points between solid particles, and the other type is composed mainly of pores and the partition walls forming the pores are solid materials. Note that in this invention, the raw material refers to the original material before shape processing, which is not shaped into a shape.

More precisely, it can be divided into those that exist as gaps or pores between particles, those that share gaps between particles and pores within particles, and those that contain foamable pores 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 pores is quite complex, and there are two main types: open pores and closed pores.
They are classified into these categories, and their structures are expressed in terms of pore volume or porosity, pore diameter and pore diameter distribution, specific surface area, etc.

Porosity is the ratio of the total pore volume of open and closed pores contained in a porous material to the total volume (bulk volume) of the material. rate,
The measurement method is a liquid or gas displacement method, an absorption method, etc., and Q is calculated as follows as a simple method as defined in JISR 2614 method for measuring specific gravity and porosity of fireproof and insulating bricks.

In addition, the ratio of the volume of curved holes to the total volume (bulk volume) of the material, that is, the void ratio, expressed as a percentage, is defined as the apparent porosity, and is defined in JISR 2205 Method for measuring apparent porosity, absorption rate, and specific gravity of firebrick. As shown, it is calculated as follows. Note that the apparent porosity is also referred to as the effective porosity.

The pore diameter is determined from the measured values of pore volume and specific surface area, and it generally ranges from the size of atoms or ions to the interfacial gap between particles, ranging from a few angstroms to a large number of angstroms. The average value is used for regular training at °C. 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.

To measure the specific surface area, the BET method is often used, which uses adsorption crosstalk at each temperature of various adsorbed gases to determine C.
In particular, nitrogen gas is often used.

Next, we will explain the absorption of light energy by a highly porous 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.

Figure 6 is a perspective view of an inorganic highly porous material, and Figure 7 is a perspective view of an inorganic highly porous material.
It is a partially enlarged sectional view of the figure. In Figure 1, ``Tame'' indicates a highly porous inorganic material, and ``(Corporate)'' indicates an opening that leads to the surface of the inorganic material. The pore diameters of the open pores [C] show a wide distribution ranging from a few microns to a large number.

Now, as shown in Figure 7, this porous material Q has the following properties:
When light enters the opening (1), it hits the wall of the inorganic substance, is reflected, undergoes multiple reflections inside the pore, and is finally absorbed 100% by the wall (C). That is, the light incident on the opening (2) is directly absorbed by the surface of the inorganic material and becomes heat within the pore.

Figure 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 when the inorganic highly porous material is placed in each model container.
There is. In FIG. 8, the horizontal axis is the apparent porosity, and the vertical axis is the pressure when the inner wall of the container is made of metal such as Cu, Fe, AI, etc., which is normalized to C. The experimental conditions were as follows: 1 AgW contact was placed in a cubic closed container with a -side of 10 cm.
Qlf! It was installed at a constant gap of IN, and a sinusoidal current arc with a peak of 10 KA was generated for 8 mS (i seconds), and the pressure inside the container generated by the energy at this time was measured.

As the inorganic highly porous material used in the above example, +, h
s Porous ceramics made by molding and sintering cordierite ceramic raw materials using methods such as adding combustible or foaming agents to create multiple pores, with an average pore size ranging from 10 to 300μ.
The apparent porosity of porous materials is 20%, 80%, 85%,
40%, 45%, 50%, 60%, 70%.

80%, 85% Monote, 50Mhl x 50fff
f X IJM” Q) Various samples were used and placed on the wall of the container so as to cover 50% 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. For absorption within the pores of parents, deep pores are effective and continuous pores are preferred. The light generated from the arc in the switch is several hundred times to 1
OOOO It is a highly porous material that is suitable for absorbing the light emitted by the arc. In particular, the pore diameter is several thousand to several hundred.
The larger the specific surface area of the pores is in the range of 0 μm, preferably the upper limit is 1000 μm or less, the more effective it is.

In experiments, it was confirmed that ``C1'' exhibits good absorption characteristics for the light emitted by the arc with an average pore diameter of 5μ to IM.Also, when the dipstick is a gas and the average pore diameter is 5μ and 20μ, it is C Good light absorption was observed.

As told by the 8th prisoner, inorganic highly porous lumber (O)
Pores have the effect of absorbing light energy and reducing the pressure inside the opening/closing turbulence.The apparent appearance of porous materials increases as the porosity increases, and becomes especially noticeable when the porosity is 35% or more. Effectiveness was confirmed up to 85%. A larger shift in porosity needs to be accommodated by further increasing the thickness of the highly porous material.

However, in terms of the relationship between porosity and mechanical strength of porous materials, when the porosity increases, it becomes brittle, has low thermal conductivity, and is easily melted by high heat, and when the porosity is low, opening and closing The effect of internal pressure is weak. Therefore, in practical use, the most apparent porous material is a brown porous material with a porosity in the range of 40 to 70%.

The characteristic trends in Figure 8 are for the functional Kata-1-L material in general.
This can be inferred from the above explanation regarding light absorption.

Conventional switches use inorganic materials.The main purpose of their use is to protect organic containers from arcing, and their properties include arc resistance, service life, and thermal conductivity. , mechanical strength, insulation, and anti-carbonization are required, and the inorganic materials that meet these requirements are inevitably designed to be densified and serve different purposes, and their apparent porosity is 2
The temperature is around 0%.

Highly porous shim materials include inorganic, metallic, and organic materials.Among them, inorganic materials have the characteristics of being insulators and high melting point materials. Since C is an electrically insulating material, it has little negative impact on cutting, and it does not melt or emit gas even when exposed to high temperatures, making it ideal as a pressure suppressing material. be.

Inorganic porous materials °C: porous ceramics, refractories,
There are glass, hardened cement, etc., and either can be used to reduce the pressure of gas inside the switch.

Next, one embodiment of the present invention will be described based on FIG. 9. In the drawing, °Cs (51 (81 is a fixed conductor and a movable conductor each having a fixed contact (6) and a HJ movable contact (9) fixed to their ends, and these constitute a fixed contact and a movable contact respectively, and both of the above The liquid contactors are arranged facing each other so that the contact points (6) and (9) come into contact with and separate from each other.

(88a) (ssb) is a light absorber, which is formed in a porous material made of an inorganic material or a composite material of inorganic and organic materials with an apparent porosity of 85% or more,
Moreover, it is arranged so as to sandwich the arc 94 generated between the contacts (6) and (9) from both sides when the contact is cut off.

(84a) (84b) is the light absorber (88a) (
°C light absorber (88a) (
88b) is a reinforcing plate integrally installed on the outer surface side of the
It is made of an insulator or a metal plate with an insulated surface.

If a switch with the above configuration is damaged, contact (6) (9
) is absorbed by the light absorbers (88a) (8ab) due to the above-mentioned action, and in this case, a reinforcing plate (
Since 34a)' (84b) is formed into a membrane, the following effects can be achieved, and a safe and highly reliable switch can be provided at a low cost.

(b) When the cover (υ base (2)
), it is no longer necessary to pay special attention to the mechanical strength of the material, and the width of the composite material can be measured. Furthermore, it is possible to select an inexpensive grade of material with low mechanical strength if the material is the same.

(b) Since the increase in internal pressure during shutoff is suppressed, the amount of sparks emitted from the switch is reduced, making it possible to prevent secondary disasters such as power supply short-circuit accidents due to arcs in large lea Mv shields and 1 hour. .

(c) The risk of damage to the light absorber due to vibrations and shocks when the switch is transported or accidentally dropped, or shocks when a large current is cut off, is eliminated by installing a reinforcing plate. Particularly, when the thickness of the light absorber is thin, the effect of the reinforcing plate 1 is large.

) Even if the light absorber is heated by the arc, heat can be efficiently conducted to the reinforcing plate and burnout of the light absorber can be prevented.

(E) Since the reinforcing plate has at least an insulating material on its surface, the legs of the arc (arc generation point) do not transfer during the arc generation period when the current is cut off, and the light absorber, which was the original purpose, can be used. Improved mechanical strength can be reliably achieved.

(f) If an inorganic, porous material containing zirconia or magnesia as a main component is used as the material for the light absorber, the surface of the light absorber will crystallize without becoming vitrified when it reaches a high temperature due to direct exposure to the arc. Therefore, the megohm on the surface of the light absorber during the arc period does not decrease and good interrupting performance can be obtained.

(g) By heat-treating the surface of a light absorber made of an inorganic porous material, or by appropriately compounding an inorganic porous material with an organic material, the vibration of the switch can be reduced without significantly hindering the internal pressure rise suppression effect. , it is possible to prevent the precipitation of fine powder from the light absorber due to impact.

In addition, FIG. 10 shows the embodiment shown in FIG. 9 in which a plurality of de-ion arc-extinguishing plates a< made of metal plates are provided. C14) can directly cool the arc (2) and ensure reliable interruption at the current zero point.

[Brief explanation of the drawing]

Figures 1 to 8 are cross-sectional views of conventional circuit breakers, each showing different operating states. Figure 4 is an explanatory diagram showing how an arc is generated between the contacts, and Figure 5 is inside the container. Fig. 6 is a perspective view showing the inorganic highly porous material, Fig. 7 is a partially enlarged sectional view of Fig. 6, and Fig. 8 shows how an arc is generated. 9 is a perspective view partially showing an embodiment of the present invention.
FIG. 0 is a perspective view partially showing another embodiment of the present invention. In the figure, (5) is a fixed conductor, (6) is a fixed contact, (8) is a movable conductor, (9) is a movable contact, a and 0 are deion arc extinguishing plates, C888') C88b') are light absorbers , (84a)
(84b) is a reinforcement board. Note that the same reference numerals in the drawings indicate the same or corresponding parts. Agent Makoto Kuzuno - Figure 3 22 (Figure 4 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10

Claims (1)

[Claims] (A device that has at least one pair of contacts that open and close, consisting of a υ conductor and a contact fixed to the conductor.) The appearance of the C1 material is an inorganic material with a porosity of 35% or more. Alternatively, at least the entire surface is insulated with a light absorber made of a porous material made of a composite material of inorganic and organic materials, and arranged so as to sandwich the arc generated between the contacts from both sides at the time of disconnection. A switch comprising a reinforcing plate integrally stacked with the light absorber on the outer surface side of the light absorber made of a material. The switch according to claim 1, characterized in that the light absorber is made of magnesia or zirconia. (4) A plurality of de-ion arc-extinguishing plates made of a magnetic material are disposed on one of the opposing light absorbers, according to any one of claims 1 to 8. switch.