JPS5828149A - Circuit breaker - 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 a circuit breaker, and more particularly to a circuit breaker with improved current-limiting performance at the time of circuit breaker.

Figure 1 (Xu is a partially cutaway plan view showing a general circuit breaker, Figure 1 (b) is t-b-b of Figure 1 (&)
FIG. In this figure, (1) is an insulating enclosure that forms the outer frame of the circuit breaker, and is equipped with an outlet (101) on the negative side wall. (2) is a fixed contact,
a fixed conductor (201) fixed to the enclosure (1);
1% (3) consisting of the fixed contact (202) fixed to the tip of the fixed conductor (201) is
), the movable conductor (501) is driven by the operation [[(4), and this movable conductor (301) ρ
It consists of a movable contact (502) that is fixed to the tip and moves toward and away from the fixed contact (202). (5) is an arc extinguishing plate that cools the arc generated when the movable contact (502) separates from the fixed contact (202).

Now, when the movable contact (302) and the fixed contact (202) are closed, the current flows from the fixed conductor (201) to the fixed contact (
202) → Port ■ Moving contact (502) → Moving conductor (30i)
flows along the route of

In this state, when a large current such as a short-circuit current flows through this circuit, the operating mechanism section (4) is activated and the movable contact (50
2) is separated from the fixed contact (202) ^ At this time,
An arc occurs between the fixed contact (202) and the movable contact (302), and the arc occurs between the fixed contact (202) and the movable contact (502).
An arc mFE is generated in between, and this arc voltage increases as the separation distance of the movable contact (502) from the fixed contact (202) increases. Further, at the same time, the arc voltage is further increased because the arc person is attracted by the magnetic force and extends in the direction of the arc extinguishing plate (6).

In this way, the arc current reaches the current zero point and the arc is extinguished, making the interruption unnecessary. During such critical operation, the movable contact (502) and the fixed contact (202)
A large amount of energy is generated by the arc A within a short period of time, ie, several milliseconds. Therefore, the temperature and pressure of the gas within the enclosure (1) rises rapidly, and this high-temperature, high-pressure gas is discharged into the atmosphere from the outlet (101).

The circuit breaker and its internal components operate as described above when breaking the circuit, but then the fixed contact (20
The operation of the 2F and the movable contact (502) will be particularly explained. Generally, arc resistance R is given by the following formula. In other words,! R= ρ- However, R: arc resistance (Ω) ρ: arc resistivity (Ω・mer) l: arc length 3) S: arc cross-sectional area (cIA) However, in general, at a large current of several KA or more and with a long arc Zal
In a short arc person where the arc is less than 50-, the arc space is occupied by metal particles. Moreover, this release of metal particles occurs in a direction perpendicular to the contact surface. In addition, the released metal particles have a humidity close to the boiling point of the contact metal at the time of release, and as soon as they are injected into the arc space, they are heated to high temperature and pressure due to the injection of electrical energy, and become conductive. It flows away from the conductor at a high speed in the opposite direction while expanding in the direction according to the pressure in the arc space. The arc resistivity β and the arc cross section Im in the arc space are determined by the waves generated by the metal particles and the direction in which they are emitted. Therefore, the arc voltage is also determined by the behavior of the metal particles. Next, the behavior of such metal particles will be explained using FIG. 2.

In FIG. 2, the X plane indicates the opposing surface when the fixed contact (202) and the movable contact (5021) come into contact, and the Y plane indicates the contact surface and a part of the conductor surface other than the X plane. The ring z indicated by a dashed line in the figure is a fixed contact (20
2) and a movable contact (302). Furthermore, 1 and b are fixed contacts (202)
, which schematically shows metal particles emitted by evaporation from the X-plane and Y-plane of the movable contact (502), and the emission direction is in the direction of each streamline indicated by arrow m and arrow n, respectively. be.

The metal particles a and b released from the fixed contact (202)% movable contact (502) rise in temperature from about 5°0000, which is the boiling point of a conductive metal, to a temperature that becomes conductive due to the energy in the arc space. In other words, the temperature is raised to s, oooa or more, or to a roughly high temperature of about 20,000a, and in the process of temperature rise, energy is removed from the arc space, lowering the temperature of the arc space, and as a result increasing the arc resistance R. .

The energy removed by the metal particles a and b from the arc space increases as the temperature of the gold particles increases, and this temperature increase is captured by the metal particles m emitted from the contacts (202) and (503). , b in arc space and the emission path. However, in the conventional circuit breaker shown in Fig. 2, the metal particles a emitted from near the center of the opposing surface, the X-plane, take away a large amount of energy from the arc space; The metal particles emitted from the Y plane take away less energy from the arc space than the metal particles A, that is, the energy of the fire source is absorbed within the range where the metal particles A flow. The temperature of the arc space decreases and therefore the arc resistivity ρ
However, in the range where metal particles flow,
In order not to take away the energy of the fire source, the temperature of the arc space decreases little, and therefore the arc resistivity ρ cannot be increased, and arc particles are generated from the opposing surface X surface and the contact surface Y surface. In addition, the arc cross section 4111 also increases - and therefore the arc resistance R also decreases.

Arc space created by such metal particles a and b (F)
Since the outflow of two energy is balanced with the electrical injection energy, if the contact (202).

(,502) If we increase the injection wave of metal particles into the arc space, which is generated between It can be seen that it is possible to increase the

Furthermore, a conventional drawback is that the material and shape of the movable conductor (501) are limited. In other words, the movable conductor (501
) has been limited in material and shape (including cross-sectional area) due to its temperature rise and strength. The material is copper or @thread material, and the shape cannot be made very small, the material cost is high, and there are limits to increasing the opening speed.

In general, the major drawback of the conventional contactor +23,' (8) is that, due to the expansion of the arc person's foot into the Y plane,
Contact points (202) and (5
02) and the conductor' (201), (301), the arc person's foot was likely to expand directly, and the heat at that time would melt the &ilA spout joint member, and there was a risk of the contact falling off. It is a point.

This invention has been made from the above point of view, and includes a pair of contacts consisting of a conductor and a contact fixed thereto, and a pressure reflector is provided on each of the conductors so as to surround the outer periphery of each of the contacts, Furthermore, by forming at least one of the pressure reflectors with a carbon fiber reinforced plastic material, the arc voltage can be greatly increased, the current limiting performance at the time of interruption can be improved, the contact can be prevented from falling off, and the material cost of the conductor can be reduced. We aim to reduce
Another object of the present invention is to provide a circuit breaker that can increase the opening speed.

Embodiments of the present invention will be described below based on the drawings.

Fig. 5 (a) is a partially cutaway plan view showing one embodiment of the circuit breaker according to the present invention, and Fig. 6 (b) is a cross-sectional view taken along the line bb--b of Fig. 6 (-). Figure 5 (&) # (b
), the enclosure (1) forming the outer frame of the circuit breaker
) is insulated by an insulator, and - there is an outlet (101) on the side wall.
I'm getting t-#. The fixed contact (2) includes a constant conductor (20f) fixed to the enclosure (1) and this fixed conductor (201
) and a fixed contact (202) attached to the tip. The movable contact (3) is the fixed contact (2
), and is separated from the movable conductor (501) and the i1 moving contact (502) attached to the tip of the movable conductor (501) opposite to the fixed contact (202). . The operating device w section (4) is for opening and closing the movable contact (3). The arc extinguishing plate (5) has a movable contact (302
) is used to extinguish the arc that occurs when g#li from the fixed contact (202).

The fixed integral (201) of the fixed contact (2) and the movable conductor (501) of the movable contact (s) have a structure surrounding the fixed contact (ffi02) and the movable contact (502) provided thereon. There are plate-shaped pressure reflectors (6) and (7) attached that face the Ark.

Both contacts (202) and (302) are pressure reflectors (a)
, protrudes from (7) and has a pressure reflector <6),
(7) is carbon fiber reinforced plastic 5x material (Garbon-
IFib@r R51forasd Plastios
;hereinafter abbreviated as Q-VB2 material).

Note that although the arc-extinguishing plate (6) does not have to be used, it is more effective to use it. The arc-extinguishing plate (5) is made of magnetic or non-magnetic material, but if a non-magnetic arc-extinguishing plate is used,
Circuit breakers with high ratings have had problems with increased humidity during rated operation, and eddy currents caused by magnetic materials were a major cause, but this problem can be eliminated.

Now, in Fig. 3, if the movable contact (502) and the fixed contact (202) are closed, the current flows through the fixed conductor (202).
1) Flows from the power supply side to the load side from the + fixed contact (202) to the movable contact (!102) to the movable conductor (301). In this state, if a large current such as a short-circuit current flows through this circuit, the operating mechanism section (4) will operate and the movable contact (50
2) is separated from the fixed contact (202). At this time,
An arc 5 is generated between the fixed contact (202) and the movable contact (302). In this arc 5, as shown in Fig. 4, the pressure reflectors (a) and (7)
4 particles a and a are reflected, the arc space becomes high EE, and as a result, the arc is effectively cooled and extinguished.

FIG. 4 is a schematic explanatory diagram of the behavior of metal particles &, O between the fixed contact (202) and the movable contact (502) in the circuit breaker of the third FIIJ. That is, as can be seen from FIG. 4, the space around the contact points (202) and (502).

The pressure value at can not be greater than the pressure value of the arc resistivity space, but at least the pressure reflector (6)
, shows an overwhelmingly higher value than the case where (γ) is not provided. Hence, the pressure reflector (6).

Surrounding space Q with considerably high pressure caused by (7)
This suppresses the expansion of the space of the arc 5 and "squeezes" the arc 5 into a narrow space. This means that the flow of metal particles 1.0 etc. emitted from the X plane, which is the opposing surface, 41m, o is squeezed into the arc space and confined, therefore, metal particles emitted from the X plane &...
(I is (effectively injected into the arc space. As a result, a large amount of effectively injected metal particles & 6) takes away a large amount of energy from the arc space that is incomparable to conventional devices. g! Cool down the leapfrog significantly. This will cause
The arc resistivity p, that is, the arc resistance R increases significantly, and the arc voltage increases significantly.

Furthermore, the material of the pressure reflectors (6) and (γ) is a-rRp.
Since the O-IFRP material is made of 0-IFRP material, the temperature of organic substances contained in the 0-IFRP material increases due to the arc and generates decomposed gas. At this time, arc j is deprived of energy to generate decomposed gas, and arc 5 is cooled by the decomposed gas. In addition, as decomposition gas is generated, the pressure on the surface of the pressure reflectors (6) and (7) increases', which promotes the narrowing effect of the arc 5 and acts on the pressure reflectors (6) and (γ). The current level increases, and the opening speed of the movable conductor (501) increases. In this way, the effect peculiar to the amount of organic material a is added to the effect of the pressure reflectors (6) and (γ) alone, and the arc voltage is further increased, thereby achieving high current limiting performance.

In addition, since 0-7RP material has very high heat resistance, it does not wear out easily even if it comes into contact with an arc, and even if the organic substances contained within it disappear, the carbon fiber remains, so it can be used as a pressure reflector (6), (7) There is no risk of falling off.

In addition, since the o-y RP material is easy to mold, it is possible to freely select the shape of the pressure reflector (6) and (γ), and since it is lightweight, it is suitable for the opening speed of the movable conductor (501). Doesn't have much impact. Also, a pressure reflector (6).

According to (7), the legs of the arc 5 expand to the X plane, and the contact points (202) and (50
2) and the conductors (201) and (301), it becomes difficult for the leg of the arc 5 to directly touch the joint between the contact point (202) and the conductor (201) and (301).
), (502) has the advantage of eliminating the risk of falling off.

FIG. 5(a) is a side view showing another embodiment of the contacts (2) and (3), and FIG. 5(b) is a side view showing another embodiment of the contacts (2) and (3) shown in FIG. (3) is a plan view of the pressure reflectors (6) and (7) shown in FIG.
01) and (501) are plate-shaped provided only on the contact side surface, as shown in FIG. 5(a).

As shown in (b), the pressure reflectors (6) and (7) are coated with 0-7RP material around the conductors (201) and (301). ,(
+Ot) may be directly added to 1llE molding. By directly pressurizing the 0-IFRP material onto the conductor, the strength of the conductor is greatly increased, and it is now possible to easily reduce the size of the conductor, which previously could not be reduced in shape (cross-sectional area) due to strength issues. In addition, low-cost aluminum, which could not be used conventionally, can be used for the movable conductor by applying pressure to the 0-IFRP material. Therefore, in this case, the weight is extremely light and The opening speed of the movable conductor becomes extremely high, and the current limiting performance and breaking performance can be further improved.

In addition, FIG. 6(&) is a side view showing another embodiment of the contacts (2) and (1), and FIG.
FIG. 2 is a plan view of the contactor shown in FIG.

That is, in some parts of the pressure reflectors (6) and (7), there is a conductor (201) extending from one end side surface of the contact points (202) and (502) as a base point and moving away from this toward the discharge port (101).
, (501) such that the surfaces of the grooves (601), (501) are exposed.
701) is provided. In this case 1, the legs of the artum run in the grooves (601) and (701), and the artum touches the arc-extinguishing plate (5) and is cooled, improving the breaking performance.

Furthermore, as shown in FIG. 6, the conductor surfaces exposed from the grooves (601) and (701) can be raised to the same level or higher than the surfaces of the pressure reflectors (6) and (7).
vl (- is the contact with a part of the bulge in °C).

Fig. 7 is a side view showing the embodiment of (1);
It is a plan view of the contact (II) shown at W(-. That is, as shown at (801) and (901), the conductor (2) exposed from the grooves (601) and (701) is
01), (501) are pressure reflectors (6), (7
) protrudes above the surface. With this configuration,
Arcum's legs quickly moved towards the outlet (101),
In addition to improving the breaking performance, the contact points (202) and (5
02) As can be seen from the above explanation, according to the present invention, the arc voltage is steadily increased, the current limiting performance at the time of interruption is improved, and the contact is prevented from falling off. It is possible to provide a circuit breaker that can reduce the material cost of the body and increase the opening speed.

[Brief explanation of the drawing]

Fig. 1(a) is a partially cutaway plan view showing a general circuit breaker, Fig. 1ri4(b) is a sectional view taken along line bb of Fig. 1 (-), and Fig. 2 is a circuit breaker of Fig. 1. A schematic explanatory diagram of the behavior of metal particles in a device, No. 5N (- is this invention, a partially cutaway plan view showing an example of a Nigaru circuit breaker, No. 5) is a schematic explanatory diagram of the behavior of metal particles in a circuit breaker, and No. 4 is a schematic explanatory diagram of the behavior of metal particles in the circuit breaker of FIG. 6, and FIG. 5 (&) is a side view showing another embodiment of the contactor. Fig. 5 (-) is a plan view of the contact shown in Fig. 5 (-), Fig. 6 (
荀 is a side view showing another embodiment of the contact, 6th figure) is a plan view of the contact shown in FIG. 6(&), 7th g: i(-
7(b) is a side view showing another embodiment of the contactor, and FIG. 7(b) is a plan view of the contactor shown in FIG. 7(&). (1) - Fixed contact, (201) - Fixed conductor, (2
02) - Fixed contact, (1) - Movable contact, (30
1) - movable conductor, (302) - amable point, (s) *
(7)-'Pressure reflector % (601). (701)-Groove• Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Ge Shuxin (1 other person)! Figure 141 (a) (b) No. 27 2

Claims (1)

[Scope of Claims] (1) Regarding a pair of contacts consisting of four contacts and a contact fixed thereto, a pressure reflector is provided on each of the conductors so as to surround the outer periphery of each of the contacts, and the A circuit breaker characterized in that at least one of the pressure reflectors is made of carbon fiber reinforced plastic material. (2) The circuit breaker according to claim 1, wherein the pressure reflector is a plate-like member provided only on the contact side surface of the conductor. +3) The circuit breaker according to claim 1, which is a coating that covers the periphery of the EE pressure reflector conductor. (4) At least one pressure reflector is provided with a groove such that the surface of the conductor is exposed in a direction away from one end side of the contact as a base point. Circuit breaker as described in section. (5)ii! A circuit breaker according to claim 4, in which the surface of the exposed conductor is raised to the same level as or higher than the surface of the pressure reflector.