KR880001825Y1 - Circuit breaker - Google Patents

Abstract

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Description

Circuit breaker

1 (a) is a plan view of a general circuit breaker.

FIG. 1 (b) is a sectional view taken along the line B-B in FIG. 1 (a).

2 is a schematic explanatory diagram of the behavior of metal particles in the circuit breaker of FIG.

Figure 3 (a) is a side view of a contactor of one embodiment used in a conventional circuit breaker.

FIG. 3 (b) is a plan view of FIG. 1 (a).

FIG. 3 (c) is a cross-sectional view taken along the line C-C in FIG. 3 (b).

FIG. 4 (a) is a side view showing the arc generation state when the conductor shown in FIG. 3 is used.

4 (b) is a front view of FIG. 4 (a).

5 is a schematic illustration of the roughness of metal particles in other conductor structures for remarks.

Figure 6 (a) is a plan view showing an embodiment of the circuit breaker according to the present invention.

Fig. 6 (b) is a side cross-sectional view taken along line B-B in Fig. 6 (a).

Fig. 7 (a), Fig. 7 (b), Fig. 6 (a) and Fig. 6 (b) show the assembly of the high and movable conductors and the arc shielding assembly.

FIG. 8 is a schematic illustration of the behavior of metal particles in the circuit breakers of FIGS. 6 (a) and 6 (b).

9 (a) and 9 (b) are perspective views showing other embodiments of the fixed contactor and the movable contactor.

10 is an assembly development view showing another embodiment of the arc shield and the fixed contact.

Figure 11 (a) is a plan view showing an embodiment of the circuit breaker leading to the present invention.

FIG. 11 (b) is a side cross-sectional view taken along the line B-B in FIG. 11 (a).

FIG. 12 is a schematic illustration of the behavior of metal particles in the circuit breaker of FIG. 11. FIG.

Figure 13 (a) is a cross-sectional view showing an embodiment of a circuit breaker according to the present invention.

Figure 13 (b) is a side cross-sectional view taken along the line B-B in Figure 13 (a).

14 (a) and 14 (b) are views of assembly development of the fixed contactor, the movable contactor and the arc shield shown in FIG. 13 (a) and FIG. 13 (b).

15 (a) and 15 (b) are exploded views of the fixed contactor, the movable contactor, and the arc shielding body according to another embodiment.

16A is a side view showing the main part of a conventional circuit breaker.

Fig. 16 (b) is a bottom view showing the movable contact of Fig. 16 (a).

17 is a perspective view of a fixed contact showing a first embodiment of a fourth embodiment of the present invention.

18 (a) is a schematic side view of a first embodiment of a fourth embodiment of the present invention.

Figure 18 (b) is a side view showing the fixed contact of Figure 18 (a).

19 (a) is a side view showing the main part of the second embodiment of the fourth embodiment of the present invention.

19 (b) is a bottom view showing the movable contact of FIG. 19 (a).

20 is a plan view of the fixed contact and the arc plate showing a third embodiment of the fourth embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

2: fixed contact 201: high conductor

202: fixed contact 203: projection

3: movable contactor 301: movable conductor

302: movable contact 5: SOHO board

501: home 6,7: arc shield

601,602,701: through hole 605,705: groove

12: arc running member 12a: one end

12a: other end

In the drawings, the same reference numerals indicate the same or corresponding parts.

The present invention relates to a circuit breaker, and more particularly to a circuit breaker with improved current-limiting performance at the time of breaking. FIG. 1 (a) is a planar cross-sectional view showing a general circuit breaker, and FIG. 1 (b) is a side cross-sectional view taken along line B-B in FIG. 1 (a). When the movable contact 302 and the fixed contact 202 are closed in FIGS. 1 (a) and 1 (b), the current is fixed conductor 201 → fixed contact 202 → movable contact 302 → movable conductor It flows in the path of 301. In this state, when a large current such as a short circuit current flows in this circuit, the operation mechanism 4 is operated to open the movable contact 302 at the fixed contact 202. At this time, arc A is generated between the fixed contact 202 and the movable contact 302 to generate an arc voltage between the fixed contact 202 and the movable contact 302.

This arc voltage rises as the opening distance of the movable contact 302 increases from the stationary contact 202. As shown in FIG. At the same time, since the arc A is pulled and extended by the magnetic force in the direction of the arc board 5, the arc voltage rises again. In this way, the arc current becomes the current zero, extinguishes arc A, and the interruption is completed. During this interruption operation, a large amount of energy is generated between the movable contact 302 and the fixed contact 202 by the arc A within a short time, that is, within the repair time. Thus, the gas temperature inside the enclosure 1 rises and the pressure rises sharply, but the gas at high temperature is released into the atmosphere from the outlet 101. The circuit breaker and its internal components operate as described above in response to the interruption.

Next, the operation of the fixed contact 202 and the movable contact 302 will be described in particular. In general, the arc resistance R is given by the following equation.

R is the arc resistance ( )

P: Arc Resistivity ( ㎡)

ι: Art length (m)

S: Arc cross section (㎡)

In general, however, in a short arc A having a large arc length ι of 50 mm or less with a large current of several KA or more, the arc space is occupied by metal particles of a conductor having arc roots on the surface. Moreover, the release of these metal particles occurs at right angles to the conductor surface.

In addition, the released metal particles have a temperature close to the boiling point of the conductor metal at the time of release, and are electrically heated at the moment when they are injected into the arc space, and then become high temperature and high pressure, and become conductive, and thus, the pressure distribution of the arc space. As it expands in the direction it flows away from the conductor at high speed.

Thus, the arc resistance of the arc space, ρ and the arc cross-sectional area S are determined by the generation amount and the discharge direction of this metal particle. Therefore, the arc voltage is also determined by the behavior of the metal particles. Next, the behavior of such metal particles will be described using FIG.

Even when the X surface is configured as a contact member, the vibration of the metal particles is not different from the following description. In FIG. 2, the pair of conductors 8 and 9 are a pair of circumferential general conductors opposite to each other, in which the conductor 8 is the positive electrode and the conductor 9 is the negative electrode. Moreover, each X surface of the conductors 8 and 9 is an opposing surface which becomes a contact surface when the conductors 8 and 9 contact, and each Y surface of the conductors 8 and 9 is an X surface which is each opposing surface. The conductor surface, which is another electrical contact surface, is shown. Even if the X plane is constituted by the contact member, the vibration of the metal particles does not change at all.

In addition, the outline Z shown by the dashed-dotted line in the figure shows the outline of the arc A which occurred between the conductors 8 and 9, and the metal particle a and the metal particle b are the X plane and Y of the conductor 8 and 9 Each metal particle generated by evaporation or the like in a plane is typically represented, and the discharge direction is each streamline direction indicated by arrow m and arrow n, respectively.

The metal particles a and b emitted from the conductors 8 and 9 are electrically conductive at a boiling temperature of about 3,000 ° C., which is the boiling temperature of the conductor metal, depending on the energy of the arc space, that is, at least 8,000 ° C. or higher. The temperature is raised to about 20,000 ° C, and the temperature of the arc space is lowered by deodorizing the energy of the arc space in the process of increasing the arc resistance R.

In addition, the amount of energy desorbed by the metal particles a and b in the arc space increases as the temperature of the metal particles increases, and the temperature rises at the position and emission path of the metal particles a and b generated in the conductors (8) and (9). Is determined by. The paths of the metal particles a and b emitted from the conductors 8 and 9 are determined in accordance with the pressure distribution of the arc space. The pressure of the arc space is determined by the combined force of the pinch force of the current itself and the thermal expansion of the metal particles a and b. The punching force is approximately determined by the density of the current, i.e., by the root size of the arc A on the conductors (8) (9).

In general, the metal particles a, b may be considered to fly while thermally expanding the space determined by the pinch force. In addition, when the root of the arc A is not restricted on the conductors 8 and 9, it is known that the metal particles a are unidirectional vapor jetted from one side conductor 9 to the other side conductor 8 to be mounted. It is becoming.

In this way, when the metal particles a are unilaterally mounted from the one-side conductor 9 to the other side conductor 8, the metal particles a injected into the positive column of arc A are usually supplied only from the one-side conductor 9.

In FIG. 2, as an example, the state of being strongly attached from the negative electrode to the positive electrode is shown, but it may be mounted in the opposite direction. The above circumstances are explained next.

In FIG. 2, for some reason, the unidirectional mounting from the conductor 9 toward the conductor 8 occurs. The metal particles a emitted from the X plane, which is the opposite plane of the conductor 9, are about to fly at right angles to the plane of the conductor, i. At this time, the metal particles a leaving the X plane of the conductor 9 are injected into the bright column by the pressure generated by the pinch force. The metal particles a leaving the X plane of the conductor 8 on the other side are pushed by the flow of the inner beam of the Yanggwangju and fail to enter the light beam discharged in the outer direction of the X plane, and escape from the system in an instant. The difference between the emission from the conductor 8 and the discharge from the conductor 9 and the vibration of the metal particles a as shown by the streamline symbol of the arrows m and m ₁ in FIG. 2 depend on the pinch force of the conductive surface as described above. This is because there is a difference in pressure caused by the pressure. In this way, the one-sided mounting in the conductor 9 is heated by the conductor 8 to be mounted, and the arc roots (anode point and cathode point) on the surface of the conductor 8 are other than the X plane on the front thereof. Zoom in on the Y plane. For this reason, the current density on the conducting surface of the conductor 8 falls, and the pressure of an arc also falls. Therefore, the unilateral mounting on the conductor 9 is made stronger.

The difference in the flight paths of the metal particles a leaving the conductors 8 and 9 generated in this way becomes the difference in the amount of energy deodorized from the arc space. Therefore, the metal particles a emitted from the X plane of the conductor 9 can sufficiently absorb energy in the positive beam, while the metal particles a emitted from the X plane of the conductor 8 do not absorb enough energy to effectively arc A. It is discharged out of the system without cooling. The metal particles b emitted from the Y plane of the floating conductors 8 and 9 do not sufficiently desorb heat from the arc A, as shown by the wired line indicated by arrow n in the figure, and increase the arc cross-sectional area S to increase the arc resistance R of the arc. Will be lowered. Thus, when there is mounting in one conductor 9, the cooling efficiency by the metallic particle a of a positive beam is low, and the metal particle generate | occur | produced in the Y surface which is a surface other than the opposing surface of both conductors 8 and 9, b hardly contributes to cooling of the bright column, and further increases the arc cross-sectional area S, so that the arc resistance R is also lowered.

Therefore, the presence of one-sided metal particles from one conductor to the other is disadvantageous in raising the arc voltage, and thus, the current-limiting performance cannot be improved at the time of breaking. In general, the fixed contactor and the movable contactor used in the conventional circuit breaker have a large surface area of the opposite surface as the conductor of the model of FIG.

Therefore, it is not limited to the root size of the generated arc, and there is an exposed surface on the side surface in addition to the opposing surface. Therefore, as described in FIG. 2, the position and size of the arc root (anode point or cathode point) generated on the positive contact surface as described in FIG. Since no limitation is imposed, in the mechanism described with reference to FIG. 2, the unidirectional mounting of the metal particles a is made from one contactor to the other contactor, so the arc cross-sectional area S becomes large. There is a flaw that does not improve.

In addition, in the example of another contactor used in the conventional circuit breaker, a part of the conductor surface near the contact is covered with an insulator 10a in order to prevent the melting of the conductor near the contact.

FIG. 3 (a) is a side view showing such a contactor 2, FIG. 3 (b) is a plan view of FIG. 3 (a), and FIG. 3 (c) is a sectional view taken along line CC of FIG. 3 (b). . In this embodiment, the tip portion of the conductor is not covered with the insulator 10a. If the X plane is made as small as possible, the density of the current on the X plane is increased to some extent, and the pinch force is increased, and at the same time, each metal particle is injected into the positive light column to some extent differently from the prior art, so that the arc voltage is higher than before. However, this alone can not prevent the expansion of the arc root on the Y plane, that is, the Y plane. As the root of the arc extends on the Y plane, the current density of the X plane decreases and the injection pressure of the metal particles decreases. Therefore, in the case of the conventional contactor, the cooling effect of the bright wine by the metal particles was not exerted to the maximum. Moreover, the major drawback of the conventional contactor is that the arc of the arc easily extends directly to the junction with the conductor, which is generally installed on the Y surface in order to enlarge the root of the arc to the Y surface, so that the low melting point joining member is melted by this heat. There is a risk of contact dropout.

An object of the present invention is to obtain a circuit breaker that has a high arc voltage and has a good current-limiting performance at the time of breaking, and furthermore there is no fear of falling off of the contact. In the circuit breaker of the present invention, a material of a high resistance material (hereinafter referred to as a high resistance material) having a higher resistivity than a material forming a conductor, leaving the electrical contact surfaces of both contact points of the circuit breaker and exposed in the peripheral space. The metal particles are forcibly injected into the arc space by bleeding behind an arc shield (plate-shaped arc shielding plate and a coating of coating and coating) of the arc shield, and the width of the tangent 202 is fixed to the high conductor ( 201), and the surface of the fixed contact 202 is more recessed than the surface of the high-conductor 201. As the high resistance material, for example, an organic or inorganic insulator or a high resistance metal such as nickel, copper, manganese, iron carbon, iron nickel or iron chromium is used. It is also possible to use iron, whose resistance increases rapidly with temperature rise.

An embodiment of the present invention will be described with reference to the drawings. FIG. 6 (a) is a plan sectional view showing an embodiment of a circuit breaker according to the present invention, and FIG. 6 (b) is a side sectional view taken along line B-B of FIG. 6 (a). 7 (a) and 7 (b) are assembly development views of the high conductor, movable conductor and arc shield shown in FIG. In Fig. 6 (a), Fig. 6 (b), Fig. 7 (a) and Fig. 7 (b), the enclosure 1 is composed of an insulator and forms the outer frame of the switchgear 101. ). The fixed contactor 2 is buried in the same width as the fixed conductor 201 and the fixed conductor 201 fixed to the enclosure 1 so as to be embedded in one end of the fixed conductor 201 than the surface of the fixed conductor 201. The fixed contact 202 is comprised.

The movable contactor 3 is opened and closed at the one end of the movable conductor 301 relative to the movable conductor 301 and the fixed contact 202 which open and close with respect to the fixed conductor 201 by opening and closing with respect to the fixed contactor 2. It consists of the same copper contact 302. The operation mechanism part 4 opens and closes the movable contactor 3. The extinguishing plate 5 extinguishes an arc that occurs when the movable contact 302 opens at the fixed contact 202. The arc shields 6 and 7 are made of the above high resistance materials, respectively, and expose the fixed contact point 202 and the movable contact point 302 at the through holes 301 and 701, respectively, so that the arc shields 6 and 7 are respectively fixed to the arc A mutually. It is installed in the conductor 201 and the movable conductor 301.

When the movable contact 302 and the fixed contact 202 are closed, current flows from the power supply side to the load side from the fixed conductor 201 to the fixed contact 202 to the movable contact 302 to the movable conductor 301. In this state, when a large current such as a short circuit current flows in the circuit, the operation mechanism 4 is operated to open the movable contact 302 at the fixed contact 202.

At this time, arc A is generated between the fixed contact 202 and the movable contact 302. In this arc A, as shown in FIG. 8, metal particles are reflected by the arc shielding bodies 6 and 7 so that the arc space becomes a high pressure, and as a result, the arc is effectively cooled and extinguished. FIG. 8 is a schematic illustration of the behavior of metal particles in the circuit breaker of FIG.

Even when the X surface is configured as a contact member, the vibration of the metal particles cannot be changed as described below. In FIG. 3, the pair of conductors 201 and 301 is formed in the same shape as that of FIG. 2, and the arc shields 6 and 7 recess the X plane, which is the opposite surface of the conductors 201 and 301, respectively. And are mounted on the conductors 201 and 301 opposite the arc A. In other words, the pressure value of the space Q cannot be higher than the space pressure value of the arc A itself, but at least displays an overwhelmingly high value as compared with the case where the arc shields 6 and 7 are not provided.

Therefore, the surrounding spaces Q and Q, which have a considerably high pressure generated by the arc shielding bodies 6 and 7, impart a force to suppress the expansion of the arc A, thereby "shrink" the arc A in a narrow space.

In other words, the wires m, m ', o, o' such as metal particles a, c emitted from the opposite X surface are reduced and closed in the arc space. Therefore, the metal particles a, c emitted from the X plane are effectively injected into the arc space. As a result, the effectively injected large amount of metal particles a, c deodorizes a large amount of energy that cannot be compared with the conventional apparatus in the arc space, thereby cooling the arc space significantly. Therefore, the resistance is increased, i.e., the arc resistance R is increased significantly, thereby raising the arc voltage very largely. As shown in FIG. 6, for example, the arc shields 6 and 7 are installed near the contact surfaces of the fixed contact 202 and the movable contact 302 to prevent arc A from moving to the conductor surface. The size of the root of arc A will also be limited. Therefore, the generation of the metal particles a, c can be concentrated on the X plane, and the arc cross-sectional area S can be reduced, further facilitating the effective arc space injection of the metal particles a, c. Therefore, the arc voltage can be further increased by further promoting the cooling of the arc space, the rise of the arc resistivity p and the rise of the arc resistance R. In addition, in the present invention, the width of the fixed contact 202 is equal to the width of the fixed conductor 201, and the fixed contact 202 is embedded to be embedded by embedding the fixed contact 202 more than the surface of the fixed conductor 201. The positioning and installation of c) can be facilitated, and the width of the arc shielding body 6 is narrowed, and at the same time, the reduction effect of the arc A becomes very large.

In addition, since the surface of the fixed contact 202 is embedded more than the surface of the high conductor 201, even if the installation position of the arc shield 6 is slightly shifted, there is no problem. Furthermore, since the fixed contact 202 is embedded in the high conductor 201, even if the arc shield 6 is consumed by the arc A, the fixed contact 201 and the high conductor 201 can be protected. .

9 (a) and 9 (b) are perspective views showing other embodiments of the fixed contactor and the movable contactor. In other words, the embodiment shown in FIG. 9 is operated by embedding the fixed contact 202 recessed than the surface of the fixed conductor 201 so that the outer peripheral cross section of the fixed contact 202 is flush with the outer peripheral cross section of the fixed conductor 201. The movable contact 302 is installed on the movable conductor 301 so that the outer end face of the contact 302 becomes flush with the outer end face of the movable conductor 301.

Accordingly, the same effects as those of the embodiment of FIG. 7 are achieved, and the positioning and installation operations of the fixed contact 202 and the movable contact 302 are made easier. Furthermore, in the above embodiment, the case where the fixed contact 202 is installed in the high conductor 201 is shown as recessed, but the movable contact 302 may be installed so as to recess the movable contact 302 in the movable conductor 301. In addition, both sides of the stationary contact 202 and the movable contact 302 may be laid in the fixed conductor 201 and the movable conductor 301 so as to be recessed. In addition, although the shape of the fixed contact 202 and the movable contact 302 is square in the above embodiment, it may be any other shape. 10 is an assembly development diagram showing another embodiment of the arc shield and the fixed contact. In FIG. 10, the groove 602 is cut so that the fixed conductor 201 may be exposed in the direction of the arc board 5 at the part adjacent to the fixed contact 202 of the arc shield 6. That is, the root of arc A travels the groove 602, and its positive liquor is greatly expanded compared with the conventional one, and is directly contacted with the arc board 5, so that a large amount of heat is absorbed, so that excellent blocking performance can be obtained and fixed. It is possible to reduce the consumption of the contact 202.

Another embodiment of the present invention will be described. As in the case of the circuit breaker described above, a part of the electrical contact surface of the contact point is left and the portion near the contact point of the conductor is negatively concealed behind the arc shield made of the material of the material, that is, the material of the high resistance material as described above. As a result, the metal particles are forcibly injected into the arc space, and the projections made of a conductive high melting point material that causes the arc current at the fixed contact point 202 or the movable contact point 302 are connected to the high conductor 201 and the movable conductor 301. Installed on at least one side.

The principle of the second embodiment according to the present invention is explained with reference to the drawings. FIG. 11 (a) is a plan sectional view showing an embodiment of a circuit breaker leading to the present invention, and FIG. 11 (b) is a side sectional view taken along line B-B of FIG. 11 (a). In FIG. 11 (a) and 11 (b), the enclosure 1 is comprised from the insulator, and forms the outer frame of a switchgear, and is provided with the discharge port 101. FIG. The fixed contact 2 is composed of a fixed conductor 201 fixed to the enclosure 1 and a fixed contact 202 mounted on one end of the fixed conductor 201. The movable contactor 3 is opened and closed with respect to the fixed contactor 2, and is provided at one end of the movable conductor 301 relative to the movable conductor 301 which is opened and closed with respect to the fixed conductor 201 and the fixed contact 202. It consists of the movable contact 302 installed. The operation mechanism part 4 opens and closes the movable contactor 3. The arc extinguishing plate 5 consumes the arc generated when the movable contact 302 opens at the fixed contact 202. The arc shields 6 and 7 are each made of the above high resistance materials, and protrude the fixed contact 202 and the movable contact 302, respectively, so that the high conductor 201 and the movable conductor 301 are opposed to the arc A, respectively. ) Is installed. When the movable contact 302 and the fixed contact 202 are closed, current flows from the power supply side to the load side with the fixed conductor 201 → the fixed contact 202 → the movable contact 302 → the movable conductor 301. In this state, when a large current such as a short-circuit current flows in this circuit, the operation mechanism 4 is operated to open the movable contact 302 at the fixed contact 202. At this time, arc A is generated between the fixed contact 202 and the movable contact 302.

In this arc A, as shown in FIG. 12, metal particles are reflected by the arc shielding bodies 6 and 7 to become a high pressure in the arc space, and the arc is effectively cooled and extinguished. FIG. 12 is a schematic illustration of the behavior of metal particles in the circuit breaker of FIG. Moreover, even when the X surface is constituted by the contact member, the vibration of the metal particles does not change as described below. In FIG. 12, the pair of conductors 8 and 9 have the same shape as that of FIG. 2, and the arc shields 6 and 7 protrude from the X plane, which is the opposite surface of the conductors 8 and 9, respectively. It was mounted on the conductors 8 and 9 opposite arc A. Of course, even when the X surface is configured as a contact member, the vibration of the metal particles is exactly the same. In other words, the pressure values in the spaces Q and Q impart a force to suppress the space diffusion of the arc A, thereby causing the arc A to be "shrunk" in a narrow space. This means that the wires m, m ', o, o') of metal particles a, c, etc. emitted from the opposite X surface are reduced in the arc space and closed. Therefore, the metal particles a, c emitted from the X plane are effectively injected into the arc space.

As a result, a large amount of the metal particles a, c effectively injected in the arc space deodorizes a large amount of energy that cannot be compared with the conventional apparatus, and thus cools the arc space significantly. Therefore, the resistivity p, that is, the arc resistance R is raised significantly, thereby raising the arc voltage extremely high. Furthermore, as shown in FIG. 11, for example, the arc shields 6 and 7 are contacted with the fixed contact 202 and the movable contact 302, i.e., near the periphery of the X plane, which is the opposite surface shown in FIG. If it is installed at, the arc A is prevented from moving to the Y surface, which is the conductor surface, thereby limiting the size of the root of the arc A. For this reason, the generation of the metal particles a, c can be concentrated on the X plane and reduced to the arc cross-sectional area S, so that the effective injection of the metal particles a, c into the arc space can be further promoted.

Therefore, the arc voltage can be raised again by further promoting the cooling of the arc space, the increase in the arc resistivity p, and the increase in the arc resistance R. FIG. 13 (a) is a plan sectional view showing an embodiment of a circuit breaker according to the present invention, and FIG. 13 (b) is a side sectional view taken along line B-B of FIG. 13 (a). 14 (a) and 14 (b) are exploded views of the fixed contactor, the movable contactor and the arc shield shown in FIG. The same reference numerals are used for the same parts as in FIG. In FIGS. 13 and 14, a fixed contact 202 is installed at the bottom of the fixed conductor 201, and the chromium alloy is located near the fixed contact 202 and in the direction of the arc flowing, that is, the arc plate 5 direction. A projection 203 made of a conductive high melting point material such as stainless steel is provided. A movable contact 302 is installed at one end of the movable conductor 301. The fixed contact 202 and the projection 203 are inserted through the through holes 601 and 602 of the arc shield 6 and the movable contact 302 is inserted through the through holes 701 of the arc shield 7. The arc shields 6 and 7 are installed on the fixed and movable conductors 201 and 301, respectively.

The operation of the embodiment of the present invention is described below. When the movable contact 302 opens at the fixed contact 202, arcing occurs between the movable contact 302 and the fixed contact 202.

This arc can transfer the spot to the projection 203 for the following reason. In other words, the arc increases the arc voltage between the fixed contact 202 and the movable contact 302 due to the action of the arc shielding bodies 6 and 7 for the above-described reasons, and the projection 203 is connected to the fixed contact 202. At the same potential, further, insulation breakdown occurs between the movable contact 302 and the projection 203 due to the high temperature caused by the arc and the position in the high-tension gas, and the arc roots on the fixed contact 202 are formed. Transition to 203. Therefore, it is possible to reduce the consumption of the fixed contact 202 and to further improve the extinguishing performance by contact with the extinguishing plate (5). In addition, since the arc shielding body conceals the outer circumference of the contact, the contact drop is completely prevented by the fact that the arc's root is not formed on the contact fixing surface, and the arc's root is transferred, thereby reducing the contact joule heat generation. Moreover, since the projection is formed of a high melting point material, even if the arc spot is moved, it is not easily consumed, and thus stable performance can be exhibited even when blocking a plurality of times.

A third embodiment of the present invention will be described. This embodiment has the same structure as that of the second embodiment described above, but only the projections are formed of a magnetically conductive conductive projection that causes the arc to flow at the fixed contact 202 or the movable contact 302. And at least one side of the movable conductor 301. In FIGS. 13 and 14, a fixed contact 202 is installed at one end of the fixed conductor 201 so that the arc flows near the fixed contact 202, that is, Nickel in the direction of the arc plate 5. Electroconductive and magnetic projections 203 made of iron and alloys thereof are provided. A movable contact 302 is installed at one end of the movable conductor 301. The fixed contact 202 and the projection 203 are inserted through the through holes 601 and 602 of the arc shield 6 and the movable contact 302 is inserted through the through holes 701 of the arc shield 7. The arc shields 6 and 7 are installed on the fixed and movable conductors 201 and 301, respectively.

The operation in the above embodiment is described below. The movable contact 302 opens at the fixed contact 202 and the arc between the contacts 302 and 202 is acted on by the arc shielding bodies 6 and 7 for the above-described reason, so that the fixed contact 202 and the movable contact ( Increasing the arc voltage between the 302 and the projection 203 is the same potential as the fixed contact 202, the projection 203 is a magnetic material, so the arc between the fixed contact 202 and the movable contact 302 Arcing projections on the fixed contact point 202 by generating insulation breakdown between the movable contact point 302 and the projection 203 due to the suction force, the high temperature caused by the arc, and the position in the high-pressure gas. Transitions to water 203. Therefore, it is possible to reduce the consumption of the fixed contact 202 and to further improve the extinguishing performance by contact with the extinguishing plate (5).

In addition, since the arc shielding body covers the contact outer circumference, contact dropout is completely prevented due to the fact that the arc is not formed on the contact fixing surface, and the Joule heat generation of the contact is reduced due to the transfer of the arc. Furthermore, the extinguishing board 5 can be extinguished even if it is not present. As the constituent material of the extinguishing board 5, either a magnetic material or a nonmagnetic material may be used.

That is, in the case of the magnetic material, the arc is cooled effectively, but in the circuit breaker having a large rated current, the temperature rise during the rated operation is a problem due to the external current generated in the magnetic material. In the case of one-sided non-magnetic material, the cooling effect of the arc is slightly reduced, but the temperature rise at the rated operation is not a problem.

Furthermore, the arc after the electric current is reduced by the reason described above, and the current-limiting continues. In addition, in the above embodiment, the projections are installed only on the high conductor side, but even if the protrusions are installed on the fixed and movable conductors, the effect is not changed and the contact consumption on both sides can be further reduced. As shown in FIG. 15 (a) and FIG. 15 (b), the through hole 601 of the arc shielding body 6 communicates with the fixed contact point 202 and the projection 203 and exposes a part of the fixed conductor. The groove 705 is provided with the communication groove 605 between the and 602 or by installing the groove 705 extending in the direction in which the arc travels on the side of the movable contact 302 in the arc shielding body 7. Exposing a part of the movable conductor to the structure may be advantageous for arc driving.

A fourth embodiment of the present invention will be described. FIG. 16 shows a state in which arc A is generated between the movable contact 5 and the fixed contact 3 of the conventional circuit breaker. As shown in FIG. 16 (a), the root of arc A is A portion thereof extends to the surface of the conductors 2 and 3, and when the opening distance increases and the length of the arc is extended, the arc A is driven in the direction of the tip of the conductor 3 so that the root of the arc A contacts the contact 302 and It is isolated at the contact 202 and shuts off when the current is zero.

At this time, the arc A is stagnant at the contacts 202 and 302 for a long time, so the consumption of the contacts 202 and 302 is severe, and it is necessary to use a large volume of contacts in view of this consumption. This embodiment is devised to solve the above-mentioned problems. It is an object of the present invention to provide a circuit breaker with excellent durability by reducing arcuate contact by shortening the arc's root from the contact within a short time by studying the arc driving path. An embodiment of the present invention will be described with reference to the drawings.

In FIG. 17, the arc shield 6 is provided on the conductor 201 of the fixed contact 2 so as to surround the outer periphery of the contact 203. As shown in FIG. The arc shield 6 is formed of a high-resistance material having a higher resistivity than the conductor 201 as in the case described above, and forms a film or is fixed on the conductor 201 by a plate as described above. Reference numeral 12 denotes an arc running member, which is made of the same material as that of the conductor 2, which is higher in conductivity than the arc shield 6, and is formed in a c-shape.

One end portion 12a of the arc traveling member 12 is formed with a razor and is screwed into a screw hole 11 formed in the conductor 2, whereby the one end portion 12a is electrically connected to the conductor 2. It is. Therefore, the conductor 2 and the arc running member 12 have the same potential. The other end 12b of the arc traveling member 12 is set apart from the conductor 2 and the arc shielding body 6 so as to be close to the contact 202.

When the fixed contactor 2 configured as described above is used, the arc A generated between the contacts 202 and 302, as shown in FIG. 18 (a), receives pressure from the arc shield 6, and the arrow 24 The root of arc A, which is reduced in the direction indicated by, is defined on the contact point 3 so as not to be larger than the size of the contact point 202. In addition, the metal particles emitted from the contacts 202 are directional and are closed in the truncated cone space forming arc A.

Therefore, as shown in FIG. 18 (b), when the vertical and horizontal distances a and b from the contact 202 to the arc traveling member 12 are properly set, the metal particles are formed at the other end of the arc traveling member 12 ( A portion thereof is directly attached to 12b), and the surface of the arc runway 12 is heated to have a sufficient surface temperature for the generation of the arc A. In such a situation, the arc A is immediately transferred to the arc running member 12 when the electromagnetic force is received in the driving direction.

The electromagnetic force is mainly caused by the electromagnetic repulsive force caused by the magnetic field induced by the current I flowing through the movable conductor 301 of FIG. 18 (a).

In order to facilitate the transition to the arc running member 12 of the arc A, it is preferable to set the distance a in FIG. 18 (b) to a value of zero or an integer and set b to an integer. The effect of the arc shield 6 not only limits the root size of arc A in FIG. 18 (a) and regulates the radial direction of the metal particles at the contact 201, but also the root of arc A that has left the contact 203 There is an effect that there is no place other than the arc running member 12, and thus the transition of the arc A is surely transferred to the arc running member 12, so that this transition is made quickly.

At this time, since the other end 12b of the traveling member 12 of the arc is separated from the conductor 201, the arc shield 6 is provided below the other end 12b, and the contact 202 is formed by the arc shield 6. Since the outer periphery of) can be completely surrounded, the effect of the arc shielding body 6 can be exhibited effectively.

In this way, the arc A is reliably transferred to the arc traveling member 12 at a time when the contact point 202 is overwhelmingly faster than in the prior art. Since the root of arc A on one movable contact 302 is naturally attracted to leave contact 302, the use of arc arcing member 12 causes the consumption of arc A of contacts 202 and 302 to be remarkable compared to the prior art. To be alleviated. FIG. 19 shows the second embodiment of the present embodiment, in which an arc shielding body 7 is provided on the movable conductor 301 of FIG. 19 (a). The groove toward the tip of the conductor 301 was cut to cut the groove toward the tip of the conductor 301 to expose the surface of the conductor 301, thereby forming the arc running path 705 having high conductivity. Made it easy to run.

In this way, arc shields (6) and (7) are provided in the two contactors (2) and (3) to limit the size of the root of the arc A to both the contactors (2) and (3). Since the metal particles emitted from the roots of arc A are effectively injected into the positive column of arc A, the arc particles are cooled by the metal particles, thereby significantly increasing the arc voltage and further improving the current-limiting performance. Immediately after the call, the current is limited to such a high arc voltage, but after some time has elapsed, the root of the arc A is transferred to the arc running member 12, so that the consumption of the contacts 202 and 302 is reduced. FIG. 20 shows a third embodiment of the present embodiment, in which a narrow groove 501 is formed in the arc extinguishing plate 5 corresponding to the arc running member 12 provided in the fixed conductor 201. As shown in FIG. According to this, the arc A transferred to the arc traveling member 12 is forcibly brought into contact with the arc extinguishing plate 5 in the narrow groove portion 501, so that the breaking performance is improved at the current zero point.

As described above, according to the present invention, a circuit breaker having a simple structure and excellent current limiting performance and low contact consumption can be obtained.

Claims (3)

A fixed contactor 2 and a movable contactor 3 each formed of a conductor and a contact fixed to the conductor, and conductive contacts provided near the contact point 202 on at least one conductor 201 of the contactor 2 and 3, respectively. Arc shields (6) (7), one end of which is formed of a fixed port material having a resistivity higher than that of the conductors, which are installed and disposed on the contacts on the conductors of the protrusions (203) and (2) (3), and one end of the protrusions (203) An arc cutting member 5 having an open cutout 501 formed therein, and an arc running member 12 having a higher conductivity than that of the arc shielding body. The arc driving member 12 has one end portion 12a electrically connected to the conductor. And the other end (12b) is set at a position proximate to the contact (202) away from the conductor. 2. The circuit breaker of claim 1, wherein the arc running member is an L-shaped rod member. The circuit breaker according to claim 1, wherein the contact surface is recessed than the surface of the conductor.