KR880000401Y1 - Circuit breaker - Google Patents

Abstract

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Description

Circuit breaker

1 (a) is a cross-sectional plan view showing a conventional circuit breaker.

Fig. 1 (b) is a side cross-sectional view taken along line b-b of Fig. 1 (a).

FIG. 2 is an explanatory view of a moving state of metal particles in the conductor of the opening and closing contact shown in FIG. 1; FIG.

Figure 3 (a) is a side view showing an embodiment of a fixed contactor used in the circuit breaker of the present invention.

3 (b) is a plan view of the fixed contact of FIG. 3 (a).

Fig. 3 (c) is a side cross-sectional view taken along line c-c of Fig. 3 (b) of the fixed contact of Fig. 3 (a).

Fig. 3 (d) is a third cross-sectional view of the d-d line of Fig. 3 (b) of the fixed contact.

The fourth (a), the fourth (b), the fourth (c), the fourth (d), the third (a), the third (b), the third (c), the third Each of the drawings (d) is the same as the side view, the plan view, the cc line side cross-sectional view, and the dd line side cross section showing the movable contactor.

5 (a) and 5 (b) are explanatory diagrams of the movement state of the metal particles in the conductor of the opening and closing contact of the circuit breaker of the present invention.

6 is a side cross-sectional view showing the operation of the circuit breaker of the present invention having the fixed and movable contactors of FIGS.

7 (a) and 7 (b) show that the arc shielding body is formed in a plate shape, and the arc traveling path is protruded at one contactor and is recommended at the other contact. Fig. 7 (a) is a perspective view of a fixed contact. . 7 (b) is a perspective view of the movable contactor.

8 (a) and 8 (b) show an embodiment in which the arc traveling route is flush with the contact, and FIG. 8 (a) is a perspective view of the fixed contact. 8 (b) is a perspective view of the movable contact.

Figure 9 (a) is a plan view of a fixed contact showing another embodiment of the arc shield.

Fig. 9 (b) is a side cross-sectional view taken along the line b-b of Fig. 9 (a).

FIG. 10 (a) and FIG. 10 (b) show an embodiment in which an arc driving path is formed of a special member, and FIG. 10 (a) is a perspective view of a fixed contact. 10 (b) is a perspective view of the movable contactor.

The present invention relates to a circuit breaker, and particularly to provide a circuit breaker with improved current-limiting performance and breaking performance at the time of breaking.

In the conventional circuit breaker, in order to extinguish arc which is formed between a pair of contacts at the time of breaking operation | movement, it was attempted to move an arc to a extinguishing device, or to speed up the detachment | detaching speed of a contact.

However, there is a drawback that the root of the arc formed between the contacts extends to the contact conductor on which the contacts are mounted, so that the arc voltage associated with arcing arc decreases.

The present invention restricts the size and position of the arc roots so that the arcs formed between the contacts do not enlarge, thereby obtaining a high arc voltage, improving the current-limiting performance of the circuit breaker, smoothing and blocking arc arc arcing. To improve performance.

That is, the present invention is to install the arc shielding body of the high resistance material to surround the contact in the contact of the circuit breaker for opening and closing the electrical circuit, and at the same time, it is more conductive than the arc shielding body adjacent to the contact and has a predetermined height and direction. A circuit breaker having an arc running path.

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

The enclosure 1 is formed of an insulator to form an outline of the switchgear, and has an outlet 101.

The fixed contactor 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 with respect to the fixed contactor 2, and corresponds to the movable conductor 301 and the fixed contact point 202 which open and close with respect to the fixed conductor 201 at the end of the movable conductor 301. The movable contact 302 is provided. The operation mechanism part 4 opens and closes the movable contactor 3.

The arc extinguishing body 5 extinguishes arc A which arises when the movable contact 302 is disengaged from the stationary contact 202, and consists of several arc extinguishing plates 501 supported by the arc extinguishing plate 502. As shown in FIG.

The arc board 501 is generally formed of a magnetic material, for example, iron. In addition, in FIG. 1 (b), for simplicity, two coefficients of the arc extinguishing plate 501 are shown, but the actual arc extinguishing body is composed of, for example, about 10 arc extinguishing plates 501.

The operating mechanism 4 and the SOHO body 5 are known, for example, US Pat. No. 3,599,130 Circuit interrupter issued to W. Mutai et.al. It was described in 1971.8.10.

The operating mechanism is also provided with a reset mechanism as specified in the above-mentioned US patent.

When the movable contact 302 and the fixed contact 202 are closed, the 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 through the circuit, the operating mechanism part 4 and the movable contact 302 are separated from the fixed contact 202.

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

This arc voltage rises as the deviation distance of the movable contact 302 from the fixed contact 202 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 pulled in the direction of the arc board 501. Therefore, arc A is pulled in the direction V of the arc extinguishing body 5, and is extended. For this reason, the arc voltage further rises.

As a means for driving the arc in the direction V of the arc extinguishing body 5, a method of using airflow is known in addition to using the magnetic field as described above. That is, the arc is driven by the airflow generated when the air in the enclosure 1, which has been high-temperature-high-pressured 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 the arc by the magnetic field, a method of using a blow out ooil, a blow out magnet or a permanent magnet, a high conductor 201 and a movable conductor A method using a parallel current flowing in the opposite direction to 301 has been known.

In this way, when the arc current reaches zero current, arcing A is extinguished to complete the interruption. In addition, when the power source is a DC power source, arc voltage above the power supply voltage is generated, which causes a current-limiting action, forcing a current zero. Therefore, in the case of the DC power supply, the same phenomenon as in the case of the current zero in the high flow described above is obtained.

During such breaking operation, a large amount of energy is generated between the movable contact 302 and the fixed contact 202 within a short time, that is, several milliseconds by the arc A. For this reason, although the gas temperature in the enclosure 1 rises and a pressure also rises abruptly, this high temperature and high pressure gas is discharged | emitted into the atmosphere from the discharge port 101. As shown in FIG.

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

That is, in general, the arc resistance R is given by the following equation.

R: Arc resistance (Ω) ρ: Arc resistivity (Ω.cm) ℓ: Arc length (cm) S: Arc cross section (cm)

In general, however, in a short arc A having a arc length of 50 cm or less as a large current of several KA or more, the arc space is filled by metal particles of a metal conductor in which arc roots exist on the surface.

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 are electrically conductive by the arc's electrical energy and at the same time, heated by the arc, resulting in high temperature. As it expands, it flows away from the highway conductor.

The arc resistance in the arc space and p and the arc cross-sectional area S are determined by the generation amount and the discharge direction of the metal particles. Therefore, the arc voltage is also determined by the movement state of such metal particles.

2 is an explanatory diagram illustrating the movement of the metal particles. In FIG. 1, the pair of conductors 6 and 7 is a pair of cylindrical cylindrical conductors facing each other. The conductor 6 is an anode and the conductor 7 is a cathode.

Moreover, 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 other than the X surface which is an opposing surface. Mark the conductor surface of. Furthermore, even when the X surface is configured as a contact member, the next movement state of the metal particles is exactly the same.

In addition, the outline Z indicated by the dashed-dotted line in the drawing indicates 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, respectively. Each metal particle generated due to evaporation or the like on the X plane and the Y plane of X is shown and its discharge direction is the direction of each current indicated by arrows m and n, respectively.

The metal particles a and b emitted from the conductors 6 and 7 are electrically conductive at about 3,000 ° C., which is the non-temperature temperature of the conductor metal by the energy of the arc space, that is, 8,000 ° C. or higher or 20,000 ° C., which is higher. The temperature is raised to a degree and deodorizes energy from the arc space during the temperature increase, thereby lowering the temperature of the arc space to increase the arc resistance R.

Furthermore, the amount of energy desorbed by the metal particles a and b in the arc space is larger as the temperature rises of the metal particles, and the temperature rise is determined by the positions and emission paths of the metal particles a and b generated in the conductors (6) and (7). do.

The paths of the metal particles a and b generated in 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 approximately determined by the density of the current, ie, by the size of the roots of the arcs a, b on the conductors 6, 7. In general, the metal particles a and b may be considered to fly while thermally expanding the space determined by the pinch force.

In addition, when the size of the root of the arc A on the conductors 6 and 7 is not limited, the metal particles a are sprayed in a unidirectional spray form from one conductor 7 to the other conductor 6. It is known.

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

In FIG. 2, the jetting from the cathode to the anode is shown as an example, but there is also a case of spraying in the opposite direction.

The phenomenon is described in more detail as follows.

That is, in FIG. 2, for this reason, it is said that unidirectional injection is carried out from the conductor 7 to the conductor 6. As shown in FIG.

The metal particles a generated on the X surface, which is the opposite surface of the conductor 7, are about to fly at right angles to the open surface of the conductor, that is, toward the arc of the arc. At this time, the metal particles a generated on the X plane of one conductor 7 are injected into the positive column by the input generated by the pinch force. On the other hand, the metal particles a starting from the X plane of the other conductor 6 are pushed out by the flow of particles in the sheep wine column and are discharged in the outer direction of the X plane so that they do not enter the sheep wine tank and are pushed out of the cleavage momentarily.

As described above, the movement of the metal particles a starting from the conductor 6 and the starting point of the conductor 7 are different from each other as shown by the streamline of arrows m and m in the second diagram. This is because there is a pressure difference due to the force.

In this way, the one-way injection from the conductor 7 heats the conductor 6 on the side to which the injection is made, and the roots of the arc (in some cases, an anode point or a cathode point) on the surface of the conductor 6 on the front X plane. It expands to other surface.

For this reason, the current density on the conductor opening surface of the conductor 6 falls, and the pressure of the arc also falls.

Therefore, the injection in the conductor 7 is further hardened. The difference between the flight paths of the conductor metal particles a starting from each of the conductors 6 and 7 thus produced is different from the amount of energy deodorized from the arc space.

That is, the metal particles a starting from the X plane of the conductor 7 can absorb sufficient energy in the positive beam, while the metal particles a starting from the X plane of the conductor 6 do not sufficiently absorb energy and thus arc A It is released out of the series without effective cooling.

In addition, since the metal particles b starting from the plane of the conductors 6 and 7 spread in the lateral direction like the streamline indicated by arrows n and n 'in the figure, not only does not deprive enough heat from the arc A but also the arc By increasing the cross-sectional area S, the arc resistance R of the arc A is lowered.

Thus, when there is injection from one conductor 7, the cooling efficiency of the light beam by the metal particle a of the other conductor 6 becomes worse, and it is other than the opposing surface of the conductors 6 and 7 of the opposite direction. The arc resistance R is also lowered because the metal particles b generated on the phosphorus Y surface do not contribute haze to the liquor cooling, but rather increase the arc cross-sectional area S.

Therefore, when there is a one-sided injection of metal particles 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 have a large surface area of the opposing surface as in the conductor of the model of FIG. 2, and thus do not limit the size of the root of the generated arc, and the contactor has a side surface other than the opposing surface. The presence of an exposed surface in copper does not limit the position and size of the root (anode or cathode) of arc, which is formed on the conductor surface as described in FIG. 2, and as described in FIG. In the unidirectional injection of the metal particles a with respect to the other contact at, the arc cross-sectional area is increased, which results in a drawback in that the current-limiting performance at the time of blocking cannot be improved.

As apparent from the above description, in order to improve the current-limiting performance of the circuit breaker, it is necessary to increase the arc voltage, and for this purpose, it is necessary to effectively inject the metal particles generated in 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 or current density of the arc root on the contactor.

Therefore, it is possible to control the 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 on the X plane of the conductor. Thus, minimizing the opposing X planes of both contacts increases the current density on the X planes to some extent, increasing 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, so that the arc voltage is conventionally Rises.

However, by this alone, the enlargement of the arc roots of the X plane, i.e., the Y plane is not supported, and as the arc roots are expanded to the Y plane, the current density of the X plane is reduced, and the injection pressure of the metal particles is lowered.

Therefore, in the case of the conventional contactor, the cooling effect of the bright wine by the injection of metal particles was not maximized. In addition, in the conventional contactor, since the root of the arc is extended to the Y surface, the root of the arc is easily extended directly to the junction between many contacts and conductors provided on this Y surface, and the joining member having a low melting point is melted by this heat. There existed a fault which was easy to drop a contact.

The circuit breaker according to the present invention is to provide a circuit breaker having a good breaking performance in the case of excessive current interruption, such as in the event of an electrical accident, and a good breaking effect even in the case of the normal tube current interruption such as an overload.

In the circuit breaker according to the present invention, an arc shield made of a high resistance material is installed on the conductor of the contactor to leave a contact contact surface of a predetermined limited area and surround the contact with the arc shield, and to maintain a predetermined height and direction. By arranging the arc running in contact with the contact point to achieve the above object.

As the high-resistance material of the arc shield, the organic or inorganic insulator or a high-resistance metal such as copper nickel, copper manganese, manganese, iron carbon, iron nickel or iron chromium is used. It is also possible to use iron whose resistance increases rapidly with temperature rise.

Temporary examples of the present invention will be described with reference to Figs. 3 (a) to 4 (d) and 5 (a).

The configuration and dimensions of the fixed contactor 2 and the movable contactor 3 of the circuit breaker of FIG. 6 will be described with reference to FIGS. 3 (a)-3 (d) and 4 (a)-(d). Explain.

The dimensions in the following description are typical values when the rated current of the circuit breaker is 100A.

As shown in detail in FIGS. 3 (a) to 3 (b), the fixed contactor 2 includes a high conductor 201 having a protrusion 203 and an arc shield 8 having a slit 801. ) And a fixed contact 202.

A typical high conductor 201 is formed of an electrical conductor, for example copper, has a width (W) of 8 mm, a height (t) of 4 mm, a width (U) of 2 mm, a height (h ₂ ) of 2.5 mm, a length ( K) The fixed contact 202 holding the 10 mm protrusion 203 on its upper surface has a height h ₁ having a bottom surface of 4.5 mm in length g ₁ and 4.5 mm in width g ₂ . This 3mm footnote is formed, and one side surface on the opposite side to the front end of the fixed contactor 2 is fixed to the upper surface of the fixed conductor 201 on the bottom surface so as to contact the first end of the protruding portion 203. The fixed contact 202 is made of a contact material such as tungsten carbide (WC) or silver alloy containing iridium.

The arc shield 8 is made of an electrical insulator such as a phenol resin or ceramic and forms a layer having a thickness of 1.5 mm covering the surface of the fixed conductor 201 near the fixed contact 202. The upper surface and the side surface of the high conductor 201 except the protrusion 203 are covered. The length l of the arc shield 8 is 25 mm.

The protrusion 203 protrudes 1 mm from the surface of the arc shield 8 through a slit 801 corresponding to the arc shield 8, and the upper surface of the protrusion 203 forms an arc running path 9. .

As the material for the arc shield 8, polyester resins, drill resins, PPS (polyphenylene sulphate) resins, PBT (polybutylene terephthalate) resins, polyoxybenziene resins, and C- Synthetic resins, such as FRP (carbon fiber lane first plastic) resin, born nitride, a vulcanized fiber, etc. are used.

Paper can also be used in circuit breakers with low rated current. In addition, since the lower surface of the high conductor 201 is fixed to the enclosure 1, the arc shield 8 is not covered. The fixed contact 202 is located in which the distance e between the one side of the front end of the fixed contactor 2 and the front end of the fixed contactor 2 becomes 3 mm.

Next, the movable contact 3 of the circuit breaker of FIG. 6 will be described with reference to FIGS. 4 (e) to 4 (d).

The movable contact 3 was composed of a movable conductor 301, a movable contact 302, and an arc shielding body 8.

The movable conductor 301 is a rod-shaped body having a width (W) of 8 mm and a thickness (t ') of 3.2 mm made of the same material as the high conductor, and a width (n') of 2 mm and a length (K ') on the lower surface thereof. ) Has a protrusion 303 of 6 mm. The movable contact 302 is fixed to the lower surface of the movable conductor 301 so as to contact one end of the protruding portion 303 opposite to the front end of the movable contact 3.

The movable contact 302 is of the same material, shape, and dimensions as the fixed contact 202, and therefore g1 '= g2' = 4.5mm, h1 '= 8mm. The arc shielding body 8 of the movable contactor 3 is formed of the same material as the arc shielding body 8 of the fixed contactor 2 to form a layer having a thickness of 1.5 mm, and the movable conductor 301 near the movable contactor 302. The surface was covered except for the lower surface and side portions of the protrusion 303.

The height h 'of the protrusion 303 is 2.5 mm, the height h' of the movable contact 302 is 3 mm, and the thickness of the arc shield 8 is 1.5 mm, so that the protrusion 303 and the movable contact 302. Silver protrudes 1 mm and 1.5 mm from the arc shield 8 surface, respectively. The upper surface of the protruding portion 303 protruding from the slit 801 provided in the arc shielding body 8 forms an arc running path 9, and the one end of the movable contacting member 3 of the protruding portion 303 and the movable contacting member 3. The edge f between the ends is 2mm.

Next, the arc that occurs when the fixed contactor 2 and the movable contactor 3 are opened is described with reference to FIG. 5 (a) for the arcing phenomenon that occurs between the contactor 2 and 3 of the circuit breaker of FIG. Explain.

In FIG. 5 (a) (to be described later with reference to FIG. 5b), the metallic expansive conductor 6 corresponds to the fixed conductor 201 shown in FIG. 1 and has a metallic cylindrical conductor 7. Corresponds to the movable conductor 301, and each of the conductors 6 and 7 is provided with an arc shielding body 8 covered by the high-resistance material 8, except for the vicinity of the X plane, which is the respective contact opposing surface. . That is, the conductor shielding surface Y surface other than the X surface which is an opposite surface is substantially coat | covered with the arc shielding body 8. Therefore, the metal particle b as in FIG. 2 which arises in this Y surface does not generate | occur | produce. Moreover, even if the Y surface is constituted by the contact member, the movement of the metal particles is exactly the same.

The contour Z of the arc, the metal particles a occurring on the conductor surface, and the arrows m, m 'indicating flight of the metal particles are the same as those described with reference to FIG.

According to this, since the Y surface is covered by the arc shielding body 8, metal particles do not generate | occur | produce in the Y surface, and the metal particle which generate | occur | produces in the surface of the conductors 6 and 7 is only the metal particle a which generate | occur | produced in the X surface. . Since the size of the roots of the arc A (anode point and cathode point) on the conductors 6 and 7 is limited, there is no case in which the root size of the arc A is enlarged.

Therefore, the size of the arc root is not expanded to cause a sudden drop in the pressure on the surface of the conductor, and the accompanying surface does not occur out of the series due to the low temperature of the metal particles. The pressure in the phase is present. As a result, the X-surface metal particles a of the conductors 6 and 7 mutually are injected into the positive beam and exhibit an effective cooling effect.

Therefore, the arc cross-sectional area S is reduced to a minimum in comparison with the conventional conductor, i.e., shown in FIG. 2, and moreover, in the case where the same current flows, the current density increases compared to the seed device shown in FIG. The quantity of the metal particles a also increases. Therefore, the amount of energy deodorized in the arc space also increases.

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, since p increases the arc resistance in the conventional case shown in FIG. 2, the arc resistance R increases. Therefore, if the current value is the same, the arc voltage also shows an extremely high value, thereby improving the current-limiting performance.

In the contactor installed in the circuit breaker according to the present invention, as shown in FIGS. 3 and 4 together with the arc shielding body, an arc driving path 9 which maintains a constant direction and play adjacent to the contact is formed.

This arc running path is more conductive than the arc shielding body, and facilitates arc directing when the arc between the contacts is introduced into the arc board for the overload current of about 6 times the circuit rated current as described below. That is, when a short circuit accident occurs, for example, when a short circuit accident occurs, when the rated current of the electric circuit reaches 100 A, for example, an excessive current of 5000 A or more flows, while an overload of the electric circuit is 600 A or less. Degree of overcurrent flows.

With respect to such an overcurrent, as described above, it is necessary to rapidly increase the arc voltage to satisfy the current-limiting action in order to prevent damage to the electric equipment connected to the electric circuit, and therefore, it must be operated so that the root of the arc does not expand. .

On the other hand, the overcurrent flowing at the time of overload should be arranged so that the arc can be sufficiently extinguished. In view of this point of the arc running path, in the case of the arc at the time of overcurrent, the arc is not expanded, and when the current value is about the degree of overcurrent, the arc is easily elongated and has a constant height. It is formed to hold.

6 is a cross-sectional side view of the circuit breaker having the fixed contactor 2 and the movable contactor 3 shown in FIGS. 3A-4D, and the parts other than the contactors 2 and 3 are the same as the circuit breaker of FIG. Consists of.

As shown in the drawing, the arc driving means formed between the contacts of the contactor causes the arc traveling path 9 to travel toward the direction V of the small arc copper plate body 5 so that the arc length is greatly extended by the draft board. The heat is absorbed in opposite directions and becomes extinguishing.

In this case, since the arc runway 9 is protruded higher than the arc shielding plate 8, arcing is smoothly performed in the direction V of the SOHO plate body 5, so that the arc shielding plate 8 and the contact 202 ( 302) can be reduced.

In addition, by the above-described transition, arc A can be quickly extinguished, which contributes to the insulation recovery between the contacts 202 and 302 which contributes to the rapid interruption of the overcurrent.

As described above, according to the present invention, a circuit breaker having excellent current-limiting and breaking performance can be obtained. The arc driving path 9 is formed in one of the embodiments shown in FIG. 3 and FIG. Even if it is formed in plural, the same effect as above can be obtained.

In addition, the arc shielding body may be configured in a plate state as shown in Example 7 (a) below. In this case, there is an effect of reducing the size of the arc root by suppressing the expansion of the arc root. That is, in FIG. 5 (b), the above-described effect is explained. In FIG. 5 (b), the pair of conductors 6 and 7 are formed in the same shape as in FIG. 2, and the plate-shaped arc shielding body 8 ( 8 is provided in the conductors 6 and 7 so that the X surface which is each opposing surface of the conductors 6 and 7 protrudes, and opposes arc A. As shown in FIG. Of course, even if the X surface is configured as a contact member, the movement of the metal particles is exactly the same.

The input values in the spaces Q and Q in the figure cannot be equal to or more than the pressure value of the arc A itself space, but at least the reports that the arc shielding bodies 8 and 8 are not provided show an overwhelmingly high value.

Therefore, the surrounding space Q, Q having a significantly high pressure generated by the arc shielding bodies 8 and 8 gives a force to suppress the expansion of the arc A, thereby reducing the arc A to a narrow space.

This means that the wires m, m 'O, O', such as metal particles a, e, etc. generated on the X plane, which are opposite surfaces, are reduced and injected into the arc space to close. Therefore, the metal particles a and e generated on the X plane are effectively injected into the arc space.

As a result, the effectively injected large amount of metal particles a.e deodorizes a large amount of energy in the arc space, thereby improving the cooling of the arc space. Therefore, the resistance is significantly increased, i.e., the arc resistance R, so that the arc voltage is extremely increased.

Further, when the arc shielding bodies 8 and 8 are installed near the contact surface between the fixed contact point and the movable contact, that is, around the opposite X surface shown in FIG. 5 (b), the arc surface moves to the Y surface. This prevents them, and also limits the size of the roots of arc A.

Therefore, the generation of the metal particles a, e can be concentrated on the X plane, and the arc cross-sectional area S can be reduced, thereby effectively promoting the arc space injection of the metal particles a, e.

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

7 (a) and 7 (b) are perspective views of the stationary contactor 2 and the movable contactor 3 including the plate-shaped arc shielding body 8 having the effects as described above.

The fixed contactor 2 of FIG. 7 (a) includes a fixed conductor 201, a fixed contact 202 formed of the same material as that of the corresponding part of the fixed contactor 2 of FIGS. It was composed of an arc shield (8).

The fixed conductor 201 and the fixed contact 202 have the same dimensions and position as those of the fixed conductor 201 and the fixed contact 2 (2) of FIGS. 3 (a) to 3 (d). 201 has no protrusion.

The arc shield 8 is a plate-shaped body having a length of 25 mm, a width of 11 mm, and a thickness of 1.5 mm, and has a slit 801 having a width of 2 mm. The slit 801 has an open end opposite to the stationary contact 202 and has a length K of 17.5 mm.

The surface of the high conductor 201 exposed by the slit 801 forms the arc path 9.

The dimensions and the like of portions other than the above description of the fixed contact of FIG. 7 (a) are the same as those of the fixed contact 2 of FIGS. 3 (a) to 3 (d).

The movable contactor 3 of FIG. 7 (b) is electrically conductive with the movable conductor 301, the movable contact 302, and the arc shield 8 formed of the same material as the corresponding portion of the fixed contactor 2 of FIG. It has a protrusion 303 formed of a material.

The protruding portion 303 is connected to the movable contact 302 and is a rectangular parallelepiped having a width of 2 mm, a length K 'of 10 mm, and a height h2' of 4 mm, and a slit 801 mounted corresponding to the arc shielding body 8. Protrude from the arch, and form an arc runway on the upper surface of the protrusion.

Dimensions of the movable contact of Fig. 7 (b) which have not been described above are the same as those of Figs. 4 (a) to 4 (d).

Thus, the arc traveling path 9 of the movable contact 3 of FIG. 7 (b) protrudes from the surface of the movable contact 302, and is located closer to the stationary contact 202, so that the contact 202 ( The arc formed between the 302 is easily guided onto the arc running path 9 so that the effect of reducing the burnout of the movable contact 302 becomes greater.

8 (a) and 8 (b) show another embodiment, the contacts 202 and 302 provided in the conductors 201 and 301 of the fixed contactor 2 and the movable contactor 3. The projections 203 and 303 of heights h2 and h2 'equal to the heights h1 and h1' of the contacts 202 and 302, and the upper surface of the contact 202 and 302. (9), the arc shielding bodies (8) and (8) are formed with slits (801) (801) as shown in correspondence with the contact point and the arc traveling path.

The arc traveling paths 9 and 9 shown in this embodiment are provided at the same height (h1 = h1 '= h2 = h2') as the contacts 202 and 302, so that the arc formed between the contacts is smoothly shifted. It is effective to let.

9 (a) is a plan view of a stationary contactor 2 showing another embodiment in which an arc shield is formed in a disc state, and FIG. 9 (b) is a cross-sectional side view taken along line b-b in FIG. 9 (a).

The arc traveling path 9 in the present embodiment is the same as that described above, but the arc shielding body 8 is a circular plane, and the action of reducing the clear arc in FIG. 5 (b) with respect to the arc formed between the contacts is the arc. It is possible to improve the current-limiting performance of the circuit breaker by acting equally on the outer circumference and raising the arc hardness by increasing the potential hardness of the photovoltaic column.

10 (a) and 10 (b) show a height h2 in the conductor 201 of the fixed contact and the conductor 301 of the movable contact corresponding to the slit of the arc shielding body 8 showing another embodiment. (h2) attaches the members 203 and 303 having a high thermal conductivity of, for example, 2 mm.

Accordingly, in addition to the effect of facilitating the transition of the arc described above, there is an effect of being heated by the arc generated between the contacts 202 and 302 to efficiently dissipate high heat of the contacts.

In addition, when the part is formed of a high melting point member such as tungsten, copper tungsten alloy, silver tungsten alloy, or nichrome cantal, which has a higher melting point than the conductor of the contactor, the frequency of the circuit breaker is high even when the frequency of use of the circuit breaker is high. Also, the arcing of the member has less effect on the contact member.

In addition, in the case of using a magnetic material such as iron or nickel, which acts as a depolarization of arc polarizer, the arc extinguishing effect during arcing is enhanced.

In the above-described embodiment can be improved back to various kinds according to the object of the present invention.

Claims (5)

A pair of contacts (2) (3) having a conductor fixed to the contact and opening and closing the electric circuit, an arc shielding body (8) installed on at least one of the contacts and having a higher resistivity than the conductor and surrounding the contact (8) And a circuit breaker having arc driving means for driving an arc formed between the pair of contacts (2) (3) in a constant direction, the contact of the contacts (2) (3) provided with the arc shield (8). 12. A circuit breaker comprising an arc circumference (9) extending adjacent to a predetermined height in a predetermined direction and having a resistivity smaller than that of the arc shield (8). 2. The circuit breaker according to claim 1, wherein the arc traveling path (9) is configured to extend in a constant direction at the same height as an adjacent contact point. According to claim 1, wherein the arc shield (8) is provided with a slit 801 extending in a predetermined direction, the arc running path (9) is installed at a constant height on the conductor corresponding to the slit (801), A circuit breaker comprising a metal piece having a higher thermal conductivity than the conductor. According to claim 1, wherein the arc shield (8) is provided with a slit 801 extending in a predetermined direction, the arc running path (9) is provided at a constant height on the conductor corresponding to the slit (801), And a circuit breaker comprising a metal surface having a higher melting point than the conductor. According to claim 1, wherein the arc shield (8) is provided with a slit 801 extending in the predetermined direction, the arc running path (9) is installed at a constant height on the conductor corresponding to the slit (801) A circuit breaker comprising metal pieces of a magnetic material having deionization of arc plasma.