KR880000361Y1 - Circuit breaker - Google Patents

Abstract

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Description

Circuit breaker

Figure 1a is a planar cross section of a general circuit breaker that can be applied to the present invention.

FIG. 1B is a side cross-sectional view of the dashed-dotted line b-b in FIG. 1A.

FIG. 1C is a perspective view of the sub-board provided in the breaker of FIG. 1A. FIG.

2 is an explanatory diagram showing the dynamics of arcs formed between the contacts of the circuit breaker of FIG.

3 is a side cross-sectional view of a circuit breaker having a fixed contactor and a movable contact according to the present invention.

4a is a side view of the fixed contact of FIG.

4B is a plan view of the fixed contact of FIG. 4A.

4C is a cross-sectional view of the dashed-dotted line c-c in FIG. 4B.

FIG. 5A is a side view of the movable contact of FIG. 3; FIG.

FIG. 5B is a bottom view of the movable contact of FIG. 5A;

FIG. 5C is a cross-sectional view of the dashed-dotted line c-c in FIG.

6 is an explanatory diagram showing arc dynamics formed at the contacts of FIG.

FIG. 7 is a view of a state similar to that of FIG. 4B, and a modified example of the fixed contact of FIG. 4B.

FIG. 8 is a view in the same state as in FIG. 4B, showing another modified example of the fixed contact of FIG.

Figure 9a is a perspective view of a fixed contact having a plate-shaped arc shield according to the present invention.

FIG. 10 is an explanatory view showing arc dynamics formed between the contacts of the fixed contactor and the movable contact shown in FIGS. 9A and 9B; FIG.

Figure 11a is an exploded perspective view of a fixed contact with a groove provided in the high conductor.

FIG. 11B is an exploded perspective view of the movable contact paired with the fixed contact of FIG. 11A; FIG.

12A is a perspective view of a stationary contact with an arc shield with a slit of zigzag.

FIG. 12B is a perspective view of the movable contact mated with the fixed contact of FIG. 12A. FIG.

FIG. 13A is an exploded perspective view of a fixed contactor having an arc running path in which a metal piece of a material different from the high conductor is fixed to the high conductor.

FIG. 13B is an exploded perspective view of the temporary contact paired with the fixed contact of FIG. 13A; FIG.

The present invention relates to a circuit breaker, and in particular, to provide a circuit breaker with improved current-limiting performance and breaking performance.

In a conventional circuit breaker, in order to extinguish arc which generate | occur | produces in a pair of contacts at the time of a breaking operation | movement, an arc was moved to the extinguishing apparatus, or the speed | rate of detachment of a contact was made high. However, the roots of arc generated between the contacts have also been extended to the contact conductors on which the contacts are mounted, thereby reducing the arc voltage associated with arc arc.

The present invention is to improve the current-limiting performance of the circuit breaker by obtaining a high arc voltage by limiting the arc and root size and position so that the arc of the arc generated between the contacts does not expand. That is, the present invention provides an arc shielding body of high resistance material around the contact of the contact of the circuit breaker for opening and closing the electric circuit, and at the same time, it is more conductive than the arc shielding body adjacent to the contact and maintains a constant width and direction. It relates to a circuit breaker formed with a.

A general circuit breaker to which the present invention can be applied will be described with reference to FIGS. 1a, 1b, and 1c.

The enclosure 1 is composed of an insulator, forms a housing of the switchgear, and has an outlet 101.

The fixed contact 2 is composed of a fixed conductor 201 fixed to the enclosure 1 and a fixed contact 202 provided at one end of the fixed conductor 201.

The movable contactor 3 is opened and closed by contact with the fixed contactor 2, and the movable conductor 301 which opens and closes with respect to the fixed conductor 20 1 and the fixed contactor 202 correspond to the movable conductor 301. It comprises a movable contact 302 provided at one end of the.

The operation mechanism part 4 opens and closes the movable contactor 3.

The arc extinguishing body 5 is arc arc A which occurs when the movable contact 302 falls from the stationary contact 202, and is comprised by the several arc extinguishing plate 501 supported by the extinguishing plate frame 502. FIG. . The arc board 501 is generally formed of a magnetic material, for example, iron.

In FIG. 1B and 1C, although the number of the arc extinguishing plates 501 is shown in figure 2 or 4, respectively for the sake of simplicity, the actual arc extinguishing board body consists of about 10 arc extinguishing plates 501, for example.

The operating mechanism 4 and the arc extinguishing body 5 are already known and are described, for example, in US Pat. No. 3,599,130 circuit interrupter (August 10, 1971).

The operating mechanism is also equipped with a reset mechanism as specified in the US patent.

When the movable contact 302 and the fixed contact 202 are in a closed state, 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 such a state, when a large current such as a short-circuit current flows in this circuit, the operation mechanism 4 is operated to cause the movable contact 372 to be separated from the fixed contact 302.

At this time, arc A is generated between the fixed contact 202 and the movable contact 202, and an arc voltage is generated between the fixed contact 202 and the movable contact 302.

This arc voltage rises as the deviation distance from the fixed contact 202 to the movable contact 302 increases.

In addition, since the arc board 501 is made of a magnetic material and has a significantly lower magnetoresistance compared to the surrounding space, the magnetic flux generated by the arc A current is reduced to the arc board 501. Is pulled in the direction V.

Therefore, arc A is pulled in the direction of the arc board 5, and is extended.

As a result, the arc voltage is further increased.

As a means for driving the arc in the direction of the arc board 5, a method of using airflow as well as using a magnetic field as described above has also been known.

That is, the arc is driven by the airflow generated when the air in the enclosure 1, which has been hot-pressed by the energy of the arc A, is discharged from the discharge port 101.

In addition to the above-described method of using the arc board 501 as a means for driving arc by magnetic field, a method using a blow out coil, a blow out magnet or a permanent magnet or a high conductor ) And a parallel current flowing through the movable conductor 301 in opposite directions have been known.

In this way, when the arc current reaches the current zero, arcing A is extinguished and the interruption is completed.

In addition, when the power source is a DC power source, arc voltage above the power source voltage is generated, which causes a current-limiting action, which creates a forced current zero.

Therefore, also in the case of a DC power supply, it becomes the same shape as the case of the current zero in AC mentioned above.

During this interruption operation, a large amount of energy is generated between the movable contact 302 and the fixed contact 202 in a short time, that is, several milliseconds.

Therefore, although the gas temperature in the enclosure 1 rises and the pressure also rises rapidly, the gas of this high temperature voltage is discharged | emitted to air | atmosphere through the discharge port 101. FIG.

Although the circuit breaker performs the blocking operation as described above, in this case, the operation of the fixed contact 202 and the movable contact 302 is analyzed as follows.

That is, the arc resistance R is generally expressed as follows.

R: Arc resistance (Ω)

ρ: Arc resistivity (Ωcm)

l: arc length (cm)

S: Arc cross section (㎠)

However, in the short arc A, which is generally a large current of several KA or more and an arc length of 1 or less, 50 mm or less, the arc space is occupied by the metal particles of the metal conductor in which the arc root exists on the surface thereof.

Moreover, the release of metal particles in this conductor occurs at right angles to the conductor surface.

In addition, the released metal particles have a temperature close to the non-kinetic point of the conductor metal when they are released, and when injected into the arc space, they become conductive by the electrical energy of the arc and at the same time, they are heated by the arc, resulting in a pressure distribution of the arc space. As it expands in the direction, it flows away from the conductor on the highway.

The arc resistivity p and the arc cross-sectional area S in the arc space are determined by the generation amount and the discharging direction of the metal particles.

Therefore, the arc voltage is also determined by the dynamics of such metal particles.

FIG. 2 is a diagram for explaining the dynamics of the above-described metal particles. In FIG. 2, the pair of conductors 6 and 7 are general conductors in the form of a pair of fasteners circumferentially opposed to each other. It is an anode and the conductor 7 is a cathode.

In addition, each X surface of the conductors 6 and 7 is an opposing surface which becomes a contact surface when the conductors 6 and 7 contact, and each Y surface of the conductors 6 and 7 is an X surface which is respectively opposing surface. The other conductor surface is shown.

Furthermore, even when the X surface is constituted by the contact member, the dynamics of the metal particles are exactly the same below.

In addition, the outline Z shown by the dashed-dotted line in the figure shows the outline of arc A occurring between the conductors 6 and 7, and the metal particles a and b emitted from the conductors are the conductors 6 and 7 As illustrated in each of the metal particles generated by evaporation and the like on the X plane and the Y plane, the discharge direction is the angular wire direction indicated by the respective arrows m and n.

The metal particles a and b emitted from the conductors 6 and 7 are electrically conductive at about 3,000 ° C., which is the boiling temperature of the conductor metal by the energy of the arc space, that is, 8,000 ° C. or higher, or 20,000, which is higher. Increase the arc resistance R by deodorizing the energy in the arc space and lowering the temperature of the arc space in the process of being heated up to about ℃.

In addition, the amount of energy desorbed by the metal particles a and b in the arc space increases as the temperature rises of the metal particles increases, and the degree of temperature rise is the position and the release path of the metal particles a and b emitted from the conductors 6 and 7. Is determined by.

The paths of the metal particles a and b emitted from the conductors 6 and 7 are determined by the pressure distribution of the arc space.

The pressure of the arc space is determined by the correlation between the pinch force of the current itself and the thermal expansion of the metal particles a and b.

The pinch force is an amount determined approximately by the density of the current, that is, the size of the arc A root on the conductors 6 and 7 is determined.

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 size of the arc A root on the conductors 6 and 7 is not limited, the metal particles a are sprayed unilaterally and sprayed from one conductor 7 to the other conductor 6. It is known.

In this way, when the metal particles a are unidirectionally injected from the conductor 7 toward the other conductor 6, the metal particles a injected into the positive column of the arc A are supplied only from one conductor 7. .

In FIG. 2, the injection from the cathode to the anode is shown to be strong, but may be sprayed in the opposite direction.

The phenomenon is described in more detail as follows.

In other words, in Fig. 2, for some reason, one-way injection is caused from the conductor 7 to the conductor 6. The metal particles a emitted from the X surface, which is the opposite surface of the conductor 7, are about to fly at right angles to the conductive surface, that is, toward the arc of the arc.

At this time, the metal particles a emitted from the X plane of the one conductor 7 are injected into the positive column by the pressure generated by the pinch force.

On the other hand, the metal particles a emitted from the X plane of the other conductor 6 are discharged in the direction of the outer surface of the X plane by being pushed by the particle flow in the sheep wine column and are pushed out momentarily without entering the sheep wine barrel. .

In this way, the action of the metal particles a differs from the emission from the conductor 6 and from the conductor 7 as shown by the streamline symbol of the arrow m, m 'in FIG. This is because there is a pressure difference caused by force.

In this way, the injection in one direction of the conductor 7 heats the conductor 6 of the axis to be injected, and draws an arc root (if necessary, an anode point or a cathode point) on the surface of the conductor 6 from the front X surface. Expand to other surfaces. For this reason, the current density on the conducting surface of the conductor 6 falls, and the pressure of an arc also falls.

Therefore, the one-way injection in the contact conductor 7 will be strengthened.

The difference in the flight path of the metal particles a of the good conductor leaving the angle bodies 6 and 7 generated in this way becomes the difference in the amount of energy deodorized in the arc space.

In other words, the metal particles a emitted from the X plane of the conductor 7 can sufficiently absorb energy from the positive beam, but the metal particles a emitted from the X plane of the conductor 6 do not sufficiently absorb energy and effectively arc A. It is released out of the system without cooling.

In addition, the metal particles b generated on the Y plane of the conductors 6 and 7 do not deprive enough heat from the arc A by increasing the arc area S by diffusing in the lateral direction as in the streamline indicated by arrows n and n 'in the drawing. As a result, the arc resistance R of the arc A is lowered. Thus, when there is injection from one of the conductors 7, the cooling efficiency of the light concentrate by the metal particles a emitted from the other of the conductors 6 becomes poor, and other than the opposing surfaces of the conductors 6 and 7 on both sides. Arc resistance R also falls by the metal particle b which generate | occur | produces in the Y surface which increases the arc cross-sectional area S, without giving contribution to positive light main cooling. Therefore, when one-sided metal particles are injected from one conductor to the other, it is disadvantageous in terms of raising the arc voltage, and thus the current-limiting performance at the time of breaking cannot be improved.

In general, the fixed contactor and the movable contactor used in the conventional circuit breaker, like the conductors of the model of FIG. 2, cannot limit the size of the arc roots generated due to the large surface area of the opposing face. Since there is an exposed surface, as described in FIG. 2, the position and size of the root (anode or cathode) of arc generated on the conductor surface cannot be limited, and as described with respect to FIG. The unidirectional injection of the metal particles a was made to the contactor on the side, which resulted in a large arc cross-sectional area, which resulted in a drawback in that the current-limiting performance at the time of breaking was not improved.

As apparent from the above description, it is necessary to increase the arc voltage in order to improve the current-limiting performance of the circuit breaker, and in order to do this, it is necessary to effectively inject metal particles generated at the root of the arc into the positive liquor. The force for injecting the metal particles into the liquor column is the pressure due to the pinch force generated at the root of the arc, and the pinch force is largely changed by the size of the arc root on the contactor or the current density.

Therefore, it is possible to control this pinch force.

For example, the conventional contactor did not play a role of limiting the size of the arc root due to the large area of the X plane of the conductor. Thus, miniaturizing the opposing X planes of the two contactors to some extent increases the density of the current on the X planes to increase the pinch force, and at the same time, each metal particle is injected into the photonic column to some extent differently from the prior art, and thus the arc voltage is It rises than before.

However, by itself, the expansion of the root of the arc on the Y surface, that is, on the Y surface cannot be prevented. As the root of the arc is expanded on the Y surface, the current density on the X surface is reduced, and the injection pressure of the metal particles is lowered.

Therefore, the conventional contactor did not maximize the cooling effect due to the injection of metal particles by the injection of metal particles. Furthermore, in the conventional contactor, in order to enlarge the arc root to the Y surface, the root of the arc is easily extended directly to the junction between the contact and the conductor, which are generally installed on the Y surface, and the joining member having a low melting point is melted by this heat. There was a drawback that the contact was easy to drop.

The circuit breaker according to the present invention is to provide a circuit breaker having a good current-limiting performance when blocking excessive currents, such as in the event of an electrical accident, and a good breaking performance even when the current and current are interrupted, such as an overload.

In the circuit breaker according to the present invention, an arc shielding body formed of a high resistance material is provided on a conductor of a contactor, and the contact shielding surface is surrounded by the arc shielding body, leaving a contact contact surface of a predetermined limited area, and the arc shielding body has a constant width and direction. The above object can be attained by providing a groove having a contact with the contact and forming an arc running path which is more conductive than the arc shielding body.

As the high-resistance material of the arc shielding body, for example, an organic or inorganic insulator, or a high-resistance metal such as copper nickel, copper manganese, manganese, iron carbon, iron necklace or iron crop is used.

It is also possible to use iron, which increases resistance rapidly with temperature rise.

Next, an embodiment of the present invention will be described with reference to FIGS. 3-5.

3 is a side cross-sectional view of one embodiment of the present invention.

The fixed contactor 2, the movable contactor 3, and other parts of the circuit breaker are configured in the same manner as the circuit breaker shown in Figs. 1A, 1B, and 1C, and the description thereof will be omitted.

Next, the shapes and dimensions of the fixed contactor 2 and the movable contactor 3 of the circuit breaker of FIG. 3 will be described in detail with reference to FIGS. 4A-4C and 5A-5C.

The following dimensions are obtained when the rated current of the circuit breaker is 100 A.

As shown in detail in FIGS. 4A-4C, the fixed contactor 2 is composed of a fixed conductor 201, an arc shield 8 having a slit 801, and a fixed contact 202.

The plate-shaped high conductor 201 is formed of an electric conductor, for example, copper, the width W is 8 mm, the thickness t is 4 mm, and the lower surface is fixed to the enclosure 1.

The fixed contact 202 is also formed of silver alloy, which is an electrical conductor, and the first h has a forward base of 4.5 mm, and a height h forms a footnote of 3 mm, and as shown in Figs. 4a-4c, The upper surface of the fixed conductor 201 is fixed to the upper surface of the tip.

As the silver alloy of the contact material, it is known to contain tungsten carbide (WC) or to contain iridium. The distance d between one side of the fixed conductor 201 front end side of the bottom of the fixed contact 202 and the front end surface of the fixed conductor 201 is about 1.5 mm.

The arc shield 8 is made of an electrically high resistance material, for example, a phenol resin or a ceramic, so that the side and the top of the high conductor 201 near the fixed contact 202 are all except the corresponding portion of the slit 801. Coated.

As the material of the arc shielding body, in addition to the ceramic and waste knot resins, polyester resins, drill resins, PPS (polyphenylene, sulfperate) resins, PBT (polybutylene terephthalate) resins, polyoxybenzirene resins, C-FRP ( Synthetic resins, such as carbon fibrous rain first and plastic) resin, thermal insulation night light, vulcanized fiber, etc. are used.

Moreover, paper can also be used as an arc shielding body 8 material in the case of a low rated current circuit breaker.

The arc shielding body covers, for example, a portion within a distance of 23 mm at a tip end surface of the high conductor 201 with a thickness of about 1.5 mm.

However, since the lower surface of the high conductor 201 is fixed to the enclosure 1, it is not necessary to cover the arc shield 8.

The slit 801 is present in the extending direction away from the tip of the fixed conductor 201 at the end of the fixed conductor 201 and the fixed contact point 202 on the opposite side, and exposes the upper surface of the fixed conductor 201. Thus, the high conductor 201 and the upper surface exposed in the slit 801 form the arc runway 9.

The slit 801 is, for example, a width of 2 mm and a length K of 10 mm. As described above, the height h of the fixed contact 202 is about 3 mm, and the thickness of the arc shield 8 is about 1.5 mm so that the fixed contact 202 protrudes only about 1.5 mm from the surface of the arc shield 8. . As shown in detail in FIGS. 5A-5C, the movable contactor 3 is also configured in substantially the same manner as the fixed contactor.

The movable conductor 301 is also made of copper, for example, and the width W 'is 8 mm and the thickness t' is 3.2 mm.

The movable contact 302 is composed of an on-alloy, which is an electrical conductor, similarly to the fixed contact 202, and has the same dimensions as the fixed contact 202.

The movable contact 302 is fixed to the lower surface of the movable conductor 301 at the upper bottom, but the distance d 'between one side of the upper bottom and the tip of the movable conductor 301 is about 8.5 mm.

The arc shield 8 covers the surface of the movable conductor 301 located in the vicinity of the movable contact 302 except for the corresponding portion of the slit 801.

The arc shield 8 covers the movable conductor surface having a thickness of 1 mm within 23 mm of the front end face of the movable conductor 301 with a thickness of about 1.5 mm.

The slit 801 has a width of 2 mm and a length K 'of 6 mm, and the surface 9 of the movable conductor 300 exposed in the slit 801 forms an arc running path 9 on the movable contact 3 side. have.

Next, FIG. 6 and FIG. 10 are explanatory diagrams which typically display the phenomenon occurring between the high conductor 201 and the movable conductor 301. FIG.

In FIG. 6 (to be described later with reference to FIG. 10), the metallic columnar conductor 6 corresponds to the high-conductor 201 shown in FIG. 1, and the metallic columnar conductor 7 is a movable body ( Corresponding to 301, the arc shields 6 and 7 are provided with arc shielding bodies 8 and 8 coated with a high resistance material except near the X plane, which is the opposing surface of each contact point.

That is, the Y surface of the conductor side surface other than the X surface as the corresponding surface is substantially covered by the arc shielding bodies 8 and 8. Therefore, the metal particle b as shown in FIG. 2 emitted from this Y surface is in the state which does not generate | occur | produce. Furthermore, even if the X surface is constituted by the contact member, the dynamics of the metal particles are exactly the same.

Further, the contour Z of the arc, the metal particles a occurring on the conductor surface, and the arrow mm 'indicating flight of the metal particles are the same as those described in FIG.

In this way, the Y surface is covered with the arc shielding body 8 so that no metal particles are released from the Y surface, and the metal particles emitted from the surface of the conductors 6 and 7 are only metal particles a emitted from the X surface.

Furthermore, since the size of the root (anode point and cathode point) of arc A on the conductors 6 and 7 is limited, the size of the root of arc A does not increase. There is no deterioration, and concomitantly, there is no phenomenon that metal particles are released out of the system at low temperature in the Y plane, so that there is a pressure on the surface of the conductive material which is suitable for the limited size.

Therefore, the metal particles a on the X plane of the conductors 6 and 7 are injected into the positive light main part to exhibit an effective cooling effect. Therefore, the arc cross-sectional area S is much smaller than that of the conventional conductor, i.e., as shown in FIG. 2, and moreover, when the same current flows, the current density increases as compared with the conventional apparatus shown in FIG. This increases the amount of energy deodorized in the arc space.

As a result, the arc space is further cooled to lower the temperature and the arc resistivity p of the arc space increases.

As described above, in the conventional case shown in FIG. 2, the arc cross-sectional area S is significantly reduced, and the arc resistance R is increased, so the arc resistance R is increased. Therefore, if the current value is the same, the arc voltage also displays an extremely high value, thereby improving the current-limiting performance.

Next, the arc shielding body provided in the circuit breaker according to the present invention is formed with the arc traveling path 9 having a predetermined direction and width adjacent to the contact as shown in detail in FIGS. 4a to 4c and 5a to 5c. .

The arc running path 9 has a higher conductivity than the arc shielding body. As described below, when the arc between the contacts generated at the time of blocking the overload current about 6 times the circuit rated current is led to the arc board, arc driving is performed. At the same time, the arc runway 9 is limited to a predetermined width so that the root of the arc is not expanded.

That is, when a short circuit accident occurs in an electric circuit in which a circuit breaker is installed, for example, when the electric circuit and the rated current are 100 A, an excessive current of 5000 A or more flows, for example, while an overload of the electric circuit is about 600 A or less. Overcurrent flows.

As described above, in order to prevent the damage of the electrical equipment connected to the electric circuit, it is necessary to rapidly increase the arc voltage to the excessive current as described above, so that the root of the arc must be prevented from expanding. .

On the other hand, in case of overcurrent of the magnitude of the amount flowing in the overload, the arc must be taken to receive sufficient extinguishing action. In view of this, the arc driving path is limited to a predetermined width, for example, 2 mm, so that the arc is not expanded in the case of the arc at the time of overcurrent, and it is easy to implement the arc when the current value is about the degree of overcurrent. .

In summary, in the circuit breaker of FIGS. 3 to 5 according to the present invention, the surface of the conductor 201 and 301 near the fixed contact 202 and the movable contact 302 is covered by the arc shielding body 8. For example, even when a large current of 5000 A or 1000 A flows, the roots of arc A formed between the contact points 202 and 302 are fixed contacts 202 and movable contacts 302 which are not covered by the arc shield 8. Is limited to the surface.

Therefore, the arc voltage of arc A is raised to achieve an effective current limit.

The width of the slit 801 provided in the arc shielding body 8 is about 2 mm in the case of the circuit breaker of 3 to 5 degrees, and is very narrow compared to the width of the contact 202 and 302, so that the root of the arc A during a large current is arc It hardly penetrates into the runway 9.

This is considered to be due to two reasons: the root area of the arc tends to be approximately proportional to the magnitude of the arc current, and the tendency of arc A to be shrunk by the pinch force applied to the arc A.

In particular, if the root of the arc A is not limited, the area of the root of the arc is approximately proportional to the current value of the arc, and according to the experimental results, the arc current value has a size of about 1 mm at 150 A.

Therefore, when the current value of arc A is reduced to about 600A from the large current value, arc A is sucked by the arc board 501, and the root of arc A is the arc board on the fixed and movable contactor (2) (3). It is moved in the direction V of 501.

As a result, the arc A is further elongated and in contact with the extinguishing plate 501 and rapidly cooled and extinguished.

In addition, even when a relatively small overcurrent of 600 A or less flows through the circuit breaker, arc A is arced by traveling the arc traveling path toward the arc board 501 as described above.

In the above description, the arc driving means for moving the arc A has been described as an arc extinguishing plate 501, but other methods such as using airflow as described above in the breaker description of FIGS. 1A to 1C are also known.

In the embodiments of FIGS. 3 to 5, the arc traveling path 9 is provided in the row of the fixed contactor 2 and the movable contactor 3, respectively, but a plurality of lines may be provided for each contactor.

7 is a plan view of the stator 2 provided with two arc runways 9 as an example.

Although the stator 2 of FIG. 7 is comprised in the same manner as the stator 2 of FIGS. 4A-4C, two slit 801 is provided in the arc shielding body 8, and these two slits 801 The exposed surface 9 of the high conductor 201 forms two arc running paths 9.

The length of the slit 801 is the same in the case of the fixed contact of Figs. 4A to 4C, but the width thereof is about 1 mm in the case of the 100A rated circuit breaker. Similarly, the movable contactor may have a structure including two arc runways.

In addition, in the embodiments of FIGS. 3 to 5, there is almost no gap between the contact and the arc shield. However, as shown in the embodiment of FIG. 8, the burnout of the arc shield due to the high heat generated at the contact is prevented. In order to maintain the contact 10, a gap 10 having a width of about 1 mm may be maintained.

The arc shielding body may be configured in the form of a plate as shown in the following example of FIG. 9A. In this case, the arc shielding body has an effect of suppressing the root expansion of the arc and reducing the dimension of the arc root.

That is, FIG. 10 illustrates the above-described effect. In FIG. 10, the pair of conductors 6 and 7 are configured in the same shape as in FIG. 2, and the plate-shaped arc shields 8 and 8 are conductors 6. It protrudes on the X surface which is an angular facing surface of (7), and is provided in the conductors 6 and 7 against the arc A.

Of course, even if the X surface is composed of a contact member, the dynamics of the next metal particles are exactly the same. Although the pressure value in the space Q, Q of the figure cannot be more than the space pressure value of the arc A itself, at least it shows an overwhelmingly high pressure value compared with the case where the arc shielding bodies 8 and 8 are not provided.

Therefore, the periphery spaces Q and Q having a significantly high pressure generated by the arc shielding bodies 8 and 8 are given a force to suppress the expansion of the arc A space, thereby limiting the arc A to a narrow space.

In other words, this constrains and concentrates the wired m, n ', 0, 0' of the metal particles a, c and the like emitted from the opposite X surface in the arc space.

Therefore, the metal particles a and c generated in the X plane are effectively injected into the arc space. As a result, a large amount of metal particles a and c effectively injected deodorize a large amount of energy in the arc space, thereby effectively cooling the arc space.

Therefore, the resistance is increased ρ, that is, the arc resistance R is remarkably raised, thereby causing the arc voltage to be raised very much. Furthermore, if this arc shielding body (8) (8) is installed near the contact surface between the fixed contact point and the movable contact, that is, the X plane main surface, which is the opposite surface shown in FIG. Arc A and root size can also be limited. Therefore, the generation of the metal particles a, c can be concentrated on the X plane and reduced to the arc cross-sectional area S, thereby more effectively promoting the injection into the arc space of the metal particles a, c.

Accordingly, the arc voltage can be further increased by further promoting the increase in the cooling arc resistivity p and the increase in the arc resistance R in the arc space.

9A and 9B are perspective views of the embodiment in which the plate-shaped arc shielding body 8 described above is provided in the stationary contactor 2 and the movable contactor 3. In this embodiment, the lower end opposite to the contact side of the arc traveling path 9 adjacent to the contact is opened. Thereby, there is an effect of preventing the local heating burnout of the arc shielding plate by the movement stop of the arc. Except for the fact that the shield 8 of the embodiment consists of a plate-shaped body having a thickness of about 1.5 mm, the shield 8 is configured in the same manner as in the embodiments of FIGS.

11A and 11B show yet another embodiment, in which the conductors 201 and 301 of the fixed contactor 2 and the movable contactor 3 correspond to the slit 801 of the arc shielding body with a width of 2 mm and a depth of 1 mm. The grooves 203 and 303 are provided to extend the arc length in the case of arc driving to increase arc resistance, thereby facilitating extinguishing action and facilitating heat dissipation of the contact.

12A and 12B show yet another embodiment, the arc running path 9 is constituted by a jig jaw to increase the arc running distance. In this way, the arc extinguishing effect during arc driving is more effectively applied, and it is appropriately included as a V-shape, a W-shape, or the like for the shape of the traveling path.

In the fixed and movable contactors of FIGS. 12A and 12B, the arc traveling path 9 has a length of about 6 mm for each straight portion, and the angle formed by two adjacent straight portions is 90 degrees. As the non-linear shape of the arc runway 9, as in this embodiment, the place where the arc travels smoothly in addition to the jig-jack shape is also considered.

13A and 13B show another embodiment of the fixed contactor 2 and the movable contactor 3, in which the conductor 201 of the fixed contactor and the conductor of the movable contactor correspond to the slit 801 of the arc shielding body 8. The elongated members 203 and 303 having a high thermal conductivity of 2 mm are attached to the 301, and the upper surface 9 is used as the arc running path 9.

The other part is configured in the same way as the contacts shown in FIGS. 9A and 9B, but the effect of the members 203 and 303 has the effect of effectively dissipating the high heat of the contact heated by the arc generated between the contacts 202 and 302. .

In the case of the materials of these members 203 and 303, for example, a circuit breaker in the case of a high melting point material such as tungsten, copper tungsten alloy, silver tungsten alloy, nichrome cantal, etc. Even when the number of times of use is high, the members 203 and 303 also deionize the arc plasma even when the arc is driven at a high frequency. For example, when magnetic materials such as iron and nickel are used, there is an effect of curing the extinguishing action during arc running.

In the above-described implementation can be variously improved according to the object of the present invention.

Claims (8)

A pair of contacts (2) and (3) which are made of a conductor fixed to a contact, which acts to open and close an electric circuit, an arc shield (8) installed at at least one contact of the contact and having a higher resistivity than the conductor, the pair A circuit breaker having arc driving means for driving an arc formed between contacts in a fixed direction, the circuit breaker extending in a direction narrower than a width of the contact adjacent to the contact of the contact provided with the arc shielding body 8 and adjacent in the predetermined direction. And an arc circuit having a resistivity lower than that of the arc shield. The method of claim 1, The arc shield (8) has a slit (slit) formed in a predetermined direction at the contact point and the surface of the conductor exposed by the slit (801) circuit breaker to form an arc running path. The method of claim 2, The slit (801) is formed through the end of the arc shielding body (8) at the contact, the arc running path is open to the conductor surface which is not covered by the arc shielding body (8). The method of claim 2, A circuit breaker in which the conductor has a groove corresponding to the slit (801), and the groove forms the arc path. The method of claim 2, The circuit breaker of which the slit (801) has a jig-jack shape. The method of claim 1, An arc shield (8) having a slit (801) formed in a constant direction, the arc circuit is installed on the conductor suitable for the slit (801), the circuit breaker made of a band metal having a higher thermal conductivity than the conductor. 2. The strip according to claim 1, wherein the arc shielding body (8) has a slit (801) formed in a predetermined direction, and the arc traveling path is provided on the conductor to fit the slit and has a melting point higher than that of the conductor. Circuit breakers made of metal. The method of claim 1, The arc shielding body 8 is provided with a slit 801 formed in a predetermined direction, the arc running path is installed on the conductor suitable for the slit 801, and the magnetic deionizing action of the arc plasma (deionizing) Circuit breakers formed of a band of metal.