JPS5975517A - 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. 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 single circuit will be explained as an example.

Figures 1 to 6 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 serves as a terminal portion to be connected to an external conductor (not shown). (7) is a movable contact, which has a movable contact (9) at one end of the moving conductor (8) opposite to the first contact (6). +10) is a movable contact device, and (11) is a movable arm that is fixed to a crossbar (12) and is configured to be opened and closed when each pole is spaced. t)8
) is an arc extinguishing chamber in which an arc extinguishing plate □4 is held by a side plate (15). (16) is a toggle link mechanism and the first link (1
It consists of η and the lower link (e). Above link (1
7) One end is at Fredle (To) - and the other end is at the bottom link (
e) are connected to one end by a shaft (sha) and ψυ, respectively. The other end of the lower link (to) is connected to the movable arm (l]) of the movable contact device (lO).

Reference numeral 4 denotes a tilting operation handle, and 2) an operating spring, which is stretched between the axis ψυ of the toggle link mechanism (16) and the operation handle body 4. (c) and (c) are thermal and electromagnetic tripping mechanisms, respectively, and when activated, the trip bar is rotated counterclockwise by the rehigh metal/1/) and the movable iron core, respectively. It has become.

4 is a latch whose one end is locked to the trip bar (c) and the other end is locked to credo/l/(to).

When the operating hand /1/ is held in the latch) and the operating hand /1/ is moved to the closing position, the toggle link mechanism (16) is extended and the axis ■υ is moved to the credo) v (19 ), and the movable contact (9) is joined to the fixed contact (6). This state is shown in Figure 1e. Then use the operating hand Ql
When the toggle link mechanism (16) is bent to the open position 1, the movable contact (9) is separated from the fully fixed contact (6), and the movable arm (11) is locked to the fredl shaft. This state is shown in Figure 2 (e) 6 Also, if an overcurrent flows in the circuit in the closed circuit state shown in Figure 1, the thermal disconnection mechanism (c) or electromagnetic trip ldf L4i1! (C) is activated and the engagement between Credo V (B) and the latch) is released, and Credo V (6)) rotates clockwise around Fredle shaft 01 and is locked with the stopper shaft. Ru. Since the connecting point between Credo/l' (to) and the upper link (17) crosses the line of action of the above-mentioned operating spring &1, the toggle link mechanism (16) is bent by the spring force of the first operating spring (C), and the crossbar is bent. Automatic shutoff is performed in conjunction with each pole by shouting.

This state t1M 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),
An arc) occurs between the fixed and movable contacts (a) and (9), and an arc voltage occurs between the fixed and movable contacts (a) and (9). This arc voltage is applied to the movable contact (9) from the fixed contact (6).
As the separation distance increases, the arc rises, and at the same time, the arc is drawn toward the arc-extinguishing plate by magnetic force and expands, so the arc rises further. In this way, the 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.

This could lead to deterioration of the insulation inside the circuit breaker, an increase in the number of sparks emitted to the outside of the circuit breaker, which could lead 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.

Figure 4 shows arc A occurring between +41 and (73) of one contact. In the figure, T is the flow of thermal energy that is conducted from arc A to the contact and escapes, and m is the flow of metal particles escaping from the arc space. The energy flow R indicates the energy flow due to light escaping from the arc space.In Fig. 4, the energy injected into the arc A is approximately divided by the three energy flows T 1 m 1 H mentioned above. Of this, heat escape T to the electrode is minute, and most of the energy is carried away by m and R. Conventionally, in the mechanism of energy consumption of arc A, the The m in the middle is overwhelmingly 4, and the simple energy has been almost ignored, but recent research by Inventor Temple has revealed that simple energy, that is, a fraction of the energy due to light, is the energy injected into the arc A. It has now been revealed that approximately 70% of students are art students.

In other words, the consumption of energy injected into the arc can be analyzed as follows.

P w = V ・I = P k −) P th
-1-P REk=-mv'-1-m-CJI)
NT However, Pw: Instantaneous injection energy V Near-ri'1 pressure: Current V・cm: Instantaneous electrical energy injected into the arc PK:
Gold - Instantaneous energy consumption carried away by particles Instantaneous energy consumption carried away m・0p-T: Gas with constant pressure specific heat Op (metal particle gas)
Instantaneous energy carried away when it escapes as wet ash T pt, h : Instantaneous energy consumption PR that escapes from the arc space to the contact by heat conduction PR From two-dimensional, the instantaneous energy radiated directly from the arc Energy dissipation gt amount The above consumption amount varies depending on the contact shape and arc length, but for arcs of 10 to 20 degrees, pk = 1
0-20%, pth=5%, PR=75-85%.

Next, FIG. 5 shows the situation when the arc A is confined in the container (3). 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). 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 temperature space filled with metal particles, and is finally irradiated onto the wall surface - this process is repeated until the amount of light reaches zero. The path of light during this time is R in the diagram.
&→Rb −+ Ro→R (indicated by 1).

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

(1) Absorption on the wall.

(2) Arc void jm and surrounding C height 2.1) Absorption by gas space, that is, absorption by gas space.

Furthermore, the light emitted from the arc spans the entire wavelength range from far ultraviolet below 2000X to far infrared above 1 μm, and consists of a continuous spectrum and a line spectrum. Even if the surface of a typical container wall is black,
It has the ability to absorb light only in the range of about 5500" from aoooK, and in other ranges it absorbs only a portion and reflects most of it. However, in the arc space and the surrounding high temperature gas space, it only has the ability to absorb light. The absorption is as follows.

When a gas space with a uniform composition and humidity over its length is irradiated with light of wavelength λ, the absorption of light by the gas space can be calculated as follows.

Equation a = Ae threat n - LIin - No. (1) Equation a: Absorption energy by gas Ae: Absorption probability [1n: Irradiated light energy n: Particle density L Length of the optical path through which the binary passes. However, equation (1) is , 6Ae indicating the amount of absorbed energy for a specific wavelength λ is the absorption probability for a specific wavelength λ,
It is a function of wavelength λ - gas temperature - particle type.

Regarding equation (1), according to the teachings of quantum mechanics, the absorption coefficient Ae is largest for gases that are in the same state as the light source gas that emits one light in both continuous and line spectra (i.e., the type of particles - wet ash are the same). It will have a value. That is, the light emitted from the arc space is absorbed most in the arc space and the surrounding gas space.

In equation (1), the amount of energy absorbed by light a is proportional to the optical path length.6@5 As shown in Figure 5, when the light from the arc space is reflected by the wall surface, L increases by -the number of reflecting surfaces, and the amount of light energy absorbed in the high temperature part of the arc space increases.

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 humidity of the gas and increasing 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. Select one or more packages of fibers, nets, and highly porous materials with an apparent porosity of 65% or more that can effectively absorb the light emitted by the arc at specific locations that receive the energy of the light. By placing
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 materials, etc., but all of them have thermal strength because they are installed in a space exposed to high-temperature arcs. There is a need.

Further, the mesh may be made of inorganic materials, metals, composite materials, etc., multi-layered thin wire meshes, knitted wires, or the like.

In the case of this net as well, it is necessary to select one that has 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.
θ and Ou are optimal, and those plated with Zn, Ni, etc. are also applicable.

Porous materials generally have a large number of pores within a solid structure, and exist in a wide range of materials such as metals, inorganic materials, and organic materials. One type is sintered and solidified at the points of contact between solid particles, and the other type is mainly composed 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.

Furthermore, it can be further classified 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 foamable pores are formed inside. . It can also be roughly divided into those that have air permeability and water permeability, and those that have independent pores inside and are not permeable.

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 the method for measuring the specific gravity and porosity of fireproof and insulating bricks in J-K5R2614.

In addition, the ratio of the open pore area to the total volume (bulk volume) of the material is the void ratio, that is, the apparent porosity expressed as a percentage, and the apparent porosity, absorption rate, and specific gravity of J-K5R2205 refractory brick are As specified in the measurement method, 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 ranges from those close to the size of atoms and ions to the interfacial gap between particles (rghc angstroms) to a few degrees, but in general, the average of the distribution is Defined as a value.

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 is determined by utilizing the adsorption crosstalk of various adsorbed gases at various humidity levels, and nitrogen gas is particularly used.

Next, the pattern of the absorption of light energy by the above-mentioned specific material, such as a porous material, which is the premise of this invention, and the resulting drop in gas pressure 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 same figure, m- indicates an opening extending through the inorganic highly porous material G. The pore diameters of the open pores vary in size from several microns to several microns.

Now, as shown by R in Figure 7, when light enters this porous material and enters the opening, the light hits the wall of the inorganic material and is reflected, and inside the pore. The light is reflected multiple times and is finally absorbed 100% by the wall. In other words, the light incident on the aperture is directly absorbed by the inorganic surface,
Heat is generated within the pores.

Figure 8 shows the apparent pores of the inorganic highly porous material -15 in a model container containing an inorganic highly porous material.
A curve diagram of the pressure change inside the model container when the pressure is changed is shown. 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 a metal such as tJu, Fe, or Al.

The experimental conditions were as follows: AgW contacts were installed at a constant gap of 10 m in a cubic sealed container with a side of -10 crn, and a peak of 1
An arc of QKA sine wave current was generated for 8 m5 (i li seconds), and the pressure inside the container generated by the energy at this time was measured.

The inorganic highly porous material used in the above examples was a ceramic raw material made of cordierite material, which was flammable, or a foaming agent.
It is made of porous ceramic material that is molded and sintered using a method such as JLI, with an average pore diameter ranging from 10 to 600μ, and the apparent porosity of the porous material is 20%.

60%, 65%, 40%, 45%, 50%, 60%, 7
0%, 80%, 85% -5 [] mm X50
Various samples of +nm

Regarding the pore diameter, the issues are the average pore diameter that slightly exceeds the wavelength region of the absorbed light and the proportion of the pores in Table 1 m, 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 generated from the arc A in the switch is several hundred A to i ouo.

Since it is distributed in X (1 μm), it slightly exceeds this,
In other words, a material with an average pore diameter of several thousand X to several thousand micrometers is suitable, and a highly porous material with an apparent porosity of 65% or more, which is the area occupied by the pores on the surface, is suitable for absorbing the light emitted by A. suitable for 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 showed good absorption characteristics for the light emitted by Arc A. It was also observed that glass materials with average pore diameters of 5 μm and 20 μm absorb light emitted by the arc well.

As can be seen from the characteristic curve 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 particularly noticeable when the porosity is 65% or higher, and the effect was confirmed in the range up to 85%.

Further increases in porosity require corresponding increases in the thickness of the highly porous material.

However, the apparent appearance of porous materials is due to the relationship between porosity and mechanical strength; when the porosity increases, it becomes brittle and has low thermal conductivity, making it easy to melt due to high heat; The effect of internal depressurization is weak. Therefore, in practical terms, the optimum porous material is a sieved porous material with a porosity in the range of 40 to 70%.

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 toward densification and have different purposes, and their apparent porosity is 2
It is around 0%.

Porous materials include inorganic, metallic, and organic materials, among which inorganic materials are characterized as insulators and materials with a melting point. These two properties make it ideal as a material to be installed inside the container of a switch, and since it is a gas insulator, it has a negative effect on shutoff. It is the best choice as a pressure suppressing material because it does not melt or emit gas even when exposed to high temperatures.

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.

Therefore, the present invention is a combination of a pressure reflector made of an organic insulating material provided on an electric contact and a light absorber made of the above-mentioned specific material provided at a position further forward in the direction of arc travel than the contact locus. The object of the present invention is to provide a switch which can not only suppress internal pressure but also improve current limiting and breaking properties.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the invention will be described below with reference to the drawings.

FIG. 9 shows an example of a circuit breaker applied to a switch according to the present invention, and the same parts as in FIGS. 1 to 6 are given the same reference numerals, and a description thereof will be omitted.

In the figure, (101) and (102) are pressure reflectors made of organic insulating material, such as well-known synthetic resin, and fixed conductors surround the outer peripheries of the fixed contact (6) and the movable contact (9), respectively. (5) and movable conductor (8)
(See Figures 10 and 11).

The pressure J reflectors (101) and (102) can be obtained by coating the conductors +51, +8+ by coating or the like, or by coating the conductors +51, +8+ with plate-shaped bodies molded from the synthetic resin.
8) can be easily formed. In that case, according to the above-mentioned covering means, it is not only easy to form, but also inexpensive, and especially on the side of the movable contact (7), an increase in the amount of J[ is suppressed, so the moment of inertia becomes small, and the movable contact (7) has the advantage that the opening speed is high, and therefore the arc voltage can be increased.

At positions on both sides of ml in front of the trajectory drawn by the contacts +61 and +93 in the arc running direction (direction of arrow a in Fig. 12), there are vertical light absorbers (10
3).

(103) is provided. These light absorbers (103
).

(IU3) is composed of one of the above-mentioned specific materials, that is, fibers, nets, and porous materials with an apparent porosity of 65% or more, or a composite material of 214 or more.

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

Arc- is generated between the rotating and movable contacts +a) and toJ, which is the same as in the conventional one, but the contact fa)
+ pressure reflectors (101), (102) on the outer periphery of
, the arc is squeezed into a narrow space. Therefore, the cross-sectional area of the pressure reflector (10
1) and (102) are extremely small compared to the conventional one without them, so the arc voltage can be greatly increased and the current limiting performance can be improved. Another feature of the present invention is that the pressure reflectors (101) and (102) are made of organic insulators, and the specific material, for example The appearance is a light absorber made of a porous material with a porosity of 65% or more (
1(35) and (103). In other words, the heat resistance of the organic insulating material is not so good, and it is rapidly consumed by the heat of the arc, releasing a large amount of evaporated particles around it. Therefore, as shown in FIG. 12, in the space X near the arc, the gas pressure increases greatly. on the other hand,
A light absorber (1
03) and (106) are installed, the light from the arc barrel is absorbed by the light absorbers (103) and (103), making it difficult for the gas pressure in the space Y to rise. Therefore, the pressure difference between the space X and the space Y causes a very thick flow of Regas to occur. That is, due to the pressure difference, the arc II quickly flows in the direction of arrow a, and the arc length is extended. For this reason, the arc) is more likely to touch the arc extinguishing plate (14), and the arc voltage increases more and more, so that the current limiting performance and breaking performance are dramatically improved.

FIG. 16 shows a modification of the fixed electrical contact (4) provided with a pressure reflector (101). The above pressure reflector (
101), there is an arc formed of a groove in the direction away from the tip (6a) of the fixed contact (6), for example, in the forward direction of the arc running direction in this example, that is, the arc extinguishing plate (1 station side). A running path (104) is formed.

If you do this, the legs of the arc (on the arc) will be on the arc running path (1
04) Upper running, arc extinguishing plate (1411111I becomes easier to turn. Therefore, arc 0 breaking is easier to arc extinguishing plate 04-)
This makes it possible to improve the short circuit performance in the small current range.

By the way, if an inorganic porous material containing magnesia or zirconia as a main component is used as the light absorber (103), (103,), the surface will be crystallized without becoming vitrified by being directly irradiated by the arc). Therefore, the insulation resistance of its surface will not decrease during the arcing period, and therefore gold-tin can have good breaking performance. Also, the light absorber C103).

If the surface of (103) is heat-treated or the inorganic porous material is individually plated with an organic phase, the light absorber (103) can be absorbed by the vibration impact of the switch without interfering with the effect of reducing the internal pressure.
It is also possible to effectively prevent the precipitation of powder from (103).

As described above, the present invention is a simple method in which a pressure reflector made of an organic insulating material is provided on the air contact, and a light absorber made of a specific material is provided on the forward side of the contact locus in the direction of arc travel. Depending on the configuration, it is possible to provide a switch with excellent current limiting and breaking properties.

[Brief explanation of the drawing]

Figures 1 to 6 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 contacts, and Figure 5 is inside a container. Fig. 6 is a perspective view showing the inorganic porous material, Fig. 7 is a partially enlarged sectional view of Fig. 6, and Fig. 8 shows when the arc is fully generated. 9 is a sectional view showing an example of a circuit breaker applied to a switch according to the present invention, and FIG. Figure 11 is a perspective view showing a fixed electrical contact r equipped with one pressure reflector, Figure 12 is an explanatory diagram of the function of the circuit breaker, and Figure 16 is FIG. 7 is a perspective view showing a modification of the constant air contact. (3)...Container, (4)...Fixed extension contact, (5
)...Fixed conductor, (6)...Fixed contact, (7)...
・Movable vehicle air contact 1,000-(8)...Movable conductor, (9)...
- Movable contacts, (101), (102)...pressure reflecting plate, (103)...light absorber, (104)...arc travel path, a...arc travel direction. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent S Nobuo - (1 other person) '('! i L)' 1 F9 Condolence 3 Shij 22 'Fig. Figure 11 Figure 12VI Figure 13

Claims (1)

[Scope of Claims] (1) At least one pair of electrical contacts, which are composed of a conductor and a contact fixed thereto, and which open and close within the container, and which is composed of an organic insulating material, and which surrounds the contact. a pressure reflector formed on the conductor so as to cover it;
The fibers, net, and appearance are equipped with a light absorber made of a porous material with a porosity of 65% or more or a composite material with a porosity of 2 or more. A switch in which the above-mentioned light-absorbing rods are respectively arranged at positions on both sides of the arc running direction fJiJ than the interlocking locus. +2) Claim 1, wherein at least one pressure reflector of the magnetic contact is provided with an arc travel path sound that extends forward in the arc travel direction from the contact point and is more conductive than the pressure reflector. The switch mentioned. (3) The switch according to claim 1 or 2, wherein the surface of the light absorber is hardened by heat treatment. (4) Claim 1, characterized in that the absorber is formed by containing magnesia or zirconia as one of its compositions so that the surface of the absorber becomes vitrified and crystallized at high temperatures. . The switch according to item 2 or 6.