KR20110044622A - Circuit breaker with arc shield - Google Patents

Abstract

The present invention is to provide a circuit breaker having a shielding device for completely shielding the rear side of the contact so that the arc can be guided toward the front side extinguishing chamber of the contact instead of the rear side of the contact. A shaft connected to the mechanism and rotatable by driving of the opening / closing mechanism, the shaft providing a driving force for rotating the movable contactor; A link connected to the shaft and transmitting a driving force; A lower shielding plate connected to the movable contactor to be rotatable with the movable contactor, the lower shielding plate extending downward from the bottom of the movable contactor to shield the arc from the lower side of the movable contactor when rotating to the blocking position; A holder connected to the link and composed of an electrical insulating material to electrically insulate the link and rotate by the link to rotate the movable contactor; And an upper shielding plate configured of an electrical insulation material and connected to a link to be elevated in an upper portion of the movable contactor according to the rotation of the movable contactor, and to shield a backward movement of the arc from the upper side of the movable contactor. do.

Circuit Breaker, Arc, Shield

Description

Circuit breaker with arc shielding device {MOLDED CASE CIRCUIT BREAKER HAVING ARC SHIELDING APPARATUS}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker, and more particularly, to a circuit breaker having an arc shielding device capable of shielding arc inflow into a rear side of a contact.

The circuit breaker detects an accident current such as short-circuit current in the power supply circuit from the power supply side to the load side and automatically cuts off the circuit to protect the load and circuit line on the circuit to which the circuit breaker is connected from the large current. A power device capable of opening and closing a relatively low voltage power circuit below volts.

An arc (conductive high-temperature and high-pressure plasma particles generated when the contacts open to each other) occurs between the movable and fixed contacts when blocking a large fault current such as a short circuit current. Quick removal is a key technology to ensure short circuit breaker performance of circuit breakers.

The present invention relates to a circuit breaker that can improve the short-circuit breaking performance, and more particularly, to a circuit breaker having a high rated voltage and a large rated current.

In such a circuit breaker, an arc extinguishing for inducing and extinguishing arcs generated between the contacts at the time of breaking the large current in front of the movable contact, that is, in front of the contacting end of the movable contact, and at the terminal side of the fixed contact. Mechanism) is installed, so the generated arc should be introduced into the corresponding extinguishing mechanism to improve the short circuit breaker performance of the circuit breaker.

However, the circuit breaker according to the prior art does not have a means for shielding the arc from moving to the space above and below the rear of the movable contact, which is separated from the fixed contact. As a result, the short-circuit breaking performance of the circuit breaker does not improve further, that is, there is a problem that does not block a large short-circuit current.

In addition, the circuit breaker according to the prior art is not provided with a means for preventing the arc from flowing from the movable contact to the opening and closing mechanism through the driving pin and the link of the holder, the opening and closing mechanism is damaged by the arc There was a problem of deterioration.

Accordingly, the present invention solves the problems of the prior art, the object of the present invention is to completely shield the arc from moving to the space above and below the rear of the movable contact is separated from the fixed contact and the arc inflow to the switchgear side It is to provide a circuit breaker that can insulate the circuit.

An object of the present invention, the fixed contactor is electrically connected to the power supply or load side and provided for each phase of the alternating current;

A movable contactor provided to correspond to the fixed contactor and having a plurality of contacts rotatable to an input position contacting the fixed contactor or a blocking position separated from the fixed contactor, and providing a path through which a current flows;

An opening / closing mechanism for driving the movable contactor to the closing position or the blocking position;

A shaft connected to the opening / closing mechanism and rotatable by driving the opening / closing mechanism, the shaft providing a driving force for rotating the movable contactor;

A link connected to the shaft to transmit a driving force;

A lower shielding plate connected to the movable contactor to be rotatable with the movable contactor and extending downward from a bottom surface of the movable contactor to shield the arc from the lower side of the movable contactor when rotating to the blocking position;

A holder connected to the link and composed of an electrically insulating material to electrically insulate the link and rotate by the link to rotate the movable contactor; And

An upper shielding plate configured of an electrical insulating material and connected to the link to be elevated in an upper portion of the movable contactor according to the rotation of the movable contactor, and to shield a rear movement of the arc from the upper side of the movable contactor. It can be achieved by providing a circuit breaker according to the invention.

The circuit breaker according to the present invention includes a lower shielding plate for shielding the arc at the bottom of the movable contactor and an upper shielding plate for shielding the rearward movement of the arc at the upper portion of the movable contactor. The shielding can be completely shielded, so that the blocking performance against a large fault current such as a short circuit current can be improved.

The circuit breaker for the circuit according to the present invention has an effect of preventing the damage or deterioration caused by the arc of the switch mechanism by blocking the path through which the arc can move from the movable contact to the link and the switch mechanism side of the upper part because the holder is composed of an electrical insulating material. Can be.

The object of the present invention and the configuration and effect of the present invention to achieve the same will be more clearly understood by the following description of the preferred embodiment of the present invention with reference to the accompanying drawings.

1 to 6, a configuration of a circuit breaker according to a preferred embodiment of the present invention will be described.

4 to 6, the circuit breaker for a circuit according to the preferred embodiment of the present invention is divided into large opening and closing mechanisms 30, shafts 21, Links 6, 22a, 22b, 22c and upper shield plate 7, movable contactor 2, lower shield plate 3, holders 4, 5 and 8, fixed contactor 1 and lower enclosure 40 It is configured to include).

As is well known, the opening / closing mechanism 30 is allowed to stand by discharging elastic energy that has been charged in a state where a spring, called a trip spring or a main spring, is not shown. It is a drive mechanism which rapidly rotates the movable contactor 2 to the position separated from the fixed contactor 1 by the elastic energy. To this end, the opening and closing mechanism 30 includes both side plates 31a and 31b for providing a supporting substrate, a handle 32 for providing a means for manually opening and closing a circuit, and a handle for providing a rotational support point of the handle 32. A lever 33 connected to a lower portion of the 32 and extending downward, a second link member 34 which transmits a driving force of the trip spring, and is composed of upper and lower link members, and one end of the handle 32. The trip spring connected to the lower portion of the lower link portion and connected to the connecting pin of the lower link member on the second link member 34, the restraining position for holding the trip spring in the state in which the elastic energy is stored, and the trip spring And a latch 35 having a position for releasing the elastic energy to rest. Since the configuration and operation of the opening and closing mechanism 30 in the circuit breaker are well known, detailed description thereof will be omitted.

The shaft 21 is connected to the opening and closing mechanism 30 and is rotatable by the driving of the opening and closing mechanism 30, and is a means for providing a driving force for rotating the movable contactor 2. In other words, the shaft 21 has an upper link provided for each phase, that is, an upper link 22c for R phase and an upper portion for S phase in order to transfer the driving force received from the opening and closing mechanism 30 to the movable contactor 2 side. It connects through the link 22b and the upper link 22a for T phases. The upper link 22c for R phase, the upper link 22b for S phase, and the upper link 22a and shaft 21 for T phase can be connected to each other integrally, for example by welding. Referring to FIG. 6, a driving pin (not shown) is fitted into the driving pin connecting hole 22b2 of the middle portion in the longitudinal direction of the upper link 22b for the S phase among the upper links. The opening and closing mechanism 30 is connected to the second link member 34 which transmits the driving force of the trip spring. Therefore, the driving force from the opening and closing mechanism 30 rotates the upper link 22b for S phase through the second link member 34, so that the shaft 30 also moves in the same direction as the upper link 22b for S phase. Will be rotated. The upper link 22c for R phase and the upper link 22a for T phase which are connected to the shaft 30 by the rotation of the shaft 30 also rotate in the same direction. The rotation of the upper link 22c for R phase, the upper link 22b for S phase, and the upper link 22a for T phase is performed through the lower link 6 and the holders 4, 5, and 8 for the movable contact 2. ), The movable contactor 2 is rotated to a circuit open position (trip or off position) separated from the corresponding fixed contactor 1 or to a circuit input position (on position) in contact with the fixed contactor 1.

4, the shaft 21 and its peripheral configuration will be described in more detail.

The shaft 21 may be composed of a metal material having a length corresponding to the width of the upper enclosure 20 or a synthetic resin pipe having a suitable mechanical strength. Both ends of the shaft 21 are composed of support ends 21a, 21b whose diameters are smaller than the rest of the middle part, and an upper enclosure 20 for supporting one support end 21b of one of these support ends 21a, 21b. Shaft support groove 20a is larger in diameter by a predetermined tolerance than support end 21b of shaft 21 but smaller than the diameter of the remaining middle portion of shaft 21. Therefore, it is possible to prevent the shaft 21 from being easily separated in the axial direction while being installed in the upper enclosure 20. The shaft support groove portion 20a of the upper enclosure 20 may be formed on only one side of both sides of the upper enclosure 20 as in the embodiment, and a modified embodiment in which two ones are provided on each side of the upper enclosure 20, respectively. It is possible. When the circuit breaker is a three-pole (upper) type circuit breaker, three upper links 22a, 22b, and 22c are provided on the shaft 21 at predetermined intervals, and the circuit breaker is a four-pole (upper) wiring. In the case of a breaker, four upper links can be installed in the shaft 21. Since the first support piece 23a and the second support piece 23b cover and support both of the support ends 21a and 21b of the shaft 21 from above, separation from the upper side of the shaft 21 can be prevented. . In order to allow the rotation of the shaft 21 and to prevent upward departure of the support ends 21a and 21b of the shaft 21, the intermediate portions of the first support piece 23a and the second support piece 23b are It has an upwardly convex shape and is provided with a tolerance from the upper surfaces of the support ends 21a and 21b. Both ends of the first support piece 23a and the second support piece 23b are provided with a screw hole allowing the fixing screw to pass therethrough, and the first supporting piece 23a and the first support piece 23a and the first supporting piece 23a and the second support piece 23b are provided therethrough. The first support piece 23a and the second support by screwing the first screw support portion 20b1 and the second screw support portion 20b2 which are provided relative to the upper enclosure 20 in correspondence with the second support piece 23b. The piece 23b is fixed in position in the upper enclosure 20.

As can be seen from FIGS. 4 to 6, the links 6, 22a, 22b, 22c include a lower link 6 and an upper link 22a, 22b, 22c. When the circuit breaker is a three-pole type circuit breaker, the upper links 22a, 22b, 22c are the upper link 22c for R phase, the upper link 22b for S phase, and the upper link 22a for T phase as described above. It can be configured as. In the case of a 4-pole type circuit breaker, an N-phase (neutral pole) upper link may be further provided in addition to the upper link.

As described above, the upper links 22a, 22b, 22c are means for transmitting the driving force from the opening and closing mechanism 30 to the lower link 6 and coaxially at predetermined intervals on the shaft 21. Is installed.

As shown in FIG. 6, the second link member 34 of the opening and closing mechanism 30 is connected to the upper link 22b for the S phase in which the opening and closing mechanism 30 is driven and connected among the upper links 22a, 22b, and 22c. And a driving pin connecting hole 22b2 for connecting by, for example, a driving pin. Therefore, when the driving force is transmitted from the second link member 34 connected by the drive pin to the upper link 22b for S phase and the upper link 22b for S phase rotates clockwise or counterclockwise, the shaft accordingly The upper link 22c for the other R phase and the upper link 22a for the T phase that are coaxially connected to the upper link 22b for the S phase through the 21 are also the same as the rotational direction of the upper link 22b for the S phase. Direction of rotation.

The lower link 6 is a means for transmitting the driving force from the upper links 22a, 22b, 22c to the wall support member 4 of the holders 4, 5, 8 and thus the lower link 6 is the upper link 22a. , 22b and 22c). In addition, when the circuit breaker for a circuit according to an embodiment of the present invention is a three-phase (pole) circuit breaker, a total of six lower links 6 are provided, one pair for each phase of an alternating current phase, and a circuit breaker according to an embodiment of the present invention. In the case of a four-phase (pole) circuit breaker, a total of eight lower links 6 are provided in pairs for each pole. The upper link 22a, 22b, 22c is provided with the link pin connection hole (refer the link pin connection hole 22b1 of the upper link 22b for S), respectively, and the upper link 22a, 22b, 22c is a link pin ( It is connected to the lower link 6 by 7a).

The upper shield plate 7 is rotatably supported by a link pin 7a connecting the upper links 22a, 22b, 22c and the lower link 6 as described above. The upper shielding plate 7 is made of an electrical insulating material, and is connected to the upper links 22a, 22b, 22c and the lower link 6 through the link pins 7a, and the upper links 22a, 22b, 22c and the lower part. In accordance with the rotation of the movable contactor 2 driven by the link 6, the movable contact 2 is provided to move up and down, and the rear movement of the arc is shielded from the upper portion of the movable contactor 2.

The upper shield plate 7 therefore has a pipe shape bearing portion 7a through which the link pin 7a penetrates. The shielding plate portion 7c is a plate-shaped portion extending from the bearing portion 7a, and the shielding plate portion 7c is a portion for shielding the rearward movement of the arc on the upper portion of the movable contactor 2.

The characteristic structure of the movable contact 2 is demonstrated with reference to FIG.

The movable contactor 2 is provided to correspond to the fixed contactor 1 and is disconnected from the closing position (aka on position) or the fixed contactor 1 which contacts the fixed contactor 1 so that the circuit can be energized so as to cut off the circuit. Means that it is rotatable to the blocking position. In the movable contactor 2, a contact assembly including a plurality of contactors (pairs) as shown in FIG. 2 is provided for each alternating current phase (pole) to provide a path through which a relatively large amount of current flows. According to an embodiment, the movable contactor 2 according to the alternating current phase is composed of a first movable contact pair 2a and a second movable contact pair 2b, and a contact constituting each pair of the movable contact pairs 2a and 2b. The free end has a contact 2a. Each contact constituting the movable contact 2 consists of an electrical conductor plate formed generally in the letter “M” having a head portion 2a1, a body portion 2a2 and a leg portion 2a3. A bearing hole 2a-1 is provided in the head of the contact to penetrate the contact in the thickness direction, and the bearing hole 2a-1 and the corresponding bearing hole 3c of the lower shielding plate 3 are arranged in communication with each other. Then, the lower shield plate 3 can be installed to be connected to the movable contactor 2 by inserting the connection pins 3d and 3d into the bearing hole 2a-1 and the bearing hole 3c. A connecting pin hole (not shown) is provided in the leg portion 2a3 of each contact constituting the movable contactor 2, and the pivot support plate 8a of the support base 8 is inserted by inserting the contact connecting pin 8a1 into the connecting pin hole. The movable contactor 2 is rotatably supported.

In this way, the movable contactor 2 is constituted by a plurality of contactors so that a large current is divided (divided) to flow, so that the conduction capacity of the movable contactor 2 can be increased.

The lower shield plate 3 is connected to the movable contactor 2 so as to be rotatable with the movable contactor 2, and extends downward from the bottom of the movable contactor 2 so that the movable contactor 2 is blocked (trip position). When the furnace rotates, the arc is shielded from the lower portion of the movable contactor (2). Therefore, the front of the contacts 2a-2 and 2b-2 based on the contacts 2a-2 and 2b-2 of the movable contactor 2, that is, the front side of the extinguishing chamber C in FIG. 6, the contact 2a-2. When the rear of 2b-2 is referred to as the rear side, the rear movement of the arc is shielded by the lower shielding plate 3 at the bottom of the movable contactor 2. The lower shielding plate 3 includes an arc-shaped bearing part 3b having a bearing hole 3c, and a plate-shaped shielding part 3a extending downward from the bearing part 3b. As described above and referring to FIG. 2, after aligning the bearing hole 2a-1 of the movable contactor 2 and the corresponding bearing hole 3c of the lower shielding plate 3, the connecting pin 3d is connected. , 3d is inserted into the bearing hole 2a-1 and the bearing hole 3c, so that the lower shield plate 3 can be installed to be connected to the movable contactor 2.

On the other hand, the configuration and function of the holder (4, 5, 8) will be described with reference to Figs.

The holders 4, 5, and 8 are connected to the link (see any of 6 and 22a, 22b, 22c in Fig. 4) and are made of an electrically insulating material so that the link (6 and 22a, 22b in Fig. 4) is formed. , 22c) electrically insulates and rotates the movable contactor (see 2 in FIG. 5) by rotating by the link (see 6 in FIG. 4 and 22a, 22b, 22c in FIG. 4). It is a means for.

The holders 4, 5, 8 comprise a supporting base 8, a holder member 5 and a wall holder 4.

As can be seen in FIG. 2, the support base 8 is a means for rotatably supporting the movable contactor 2, and includes a rotation support plate 8a and a fixed base 8b. The fixed base 8b is fixedly installed in a predetermined accommodation space in the lower enclosure 40 of the circuit breaker according to the present invention. The pivot support plate 8a is connected to the fixed base 8b via a hinge pin (not shown) and rotatably supported by the fixed base 8b.

The holder member 5 is connected to the support base 8, in particular the pivot support plate 8a of the support base 8, to rotationally drive the pivot support plate 8a of the support base 8, in particular the support base 8. . The holder member 5 is comprised including both side plates and the connection part which connects between the said side plates. Each of the side plates of the holder member 5 is provided with a pair of connecting ports 5b and 5c along a diagonal line to allow the connecting pin to be inserted so that the connecting pin can be connected to the wall supporting member 4 described later. One holder bearing hole 8a2 is provided which allows the connecting pin to be connected to the pivot support plate 8a of (8) to be inserted.

As can be seen from FIGS. 3 and 6, the wall support member 4 consists of an electrical insulation material to electrically insulate the links 6, 22a, 22b, 22c, in particular the lower link 6, and to provide a link 6. And means for transmitting the driving force transmitted from the 22a, 22b, 22c to the rotation support plate 8a of the support base 8 so as to rotate through the holder member 5. The wall support member 4 is connected to the holder member 5 for this function, in particular to the lower link 6 of the links 6, 22a, 22b, 22c and with the movable contactor 2 interposed therebetween. It is installed on both sides of the movable contactor. As shown in FIG. 3, the wall support member 4 includes a first wall support member 4a and a second wall support member 4a 'provided at a predetermined distance from each other. The first wall supporting member 4a and the second wall supporting member 4a 'are connected to each other by a connecting pin (not shown) with one lower end of the lower link 6 provided one by one (upper). The first wall support member 4a and the second wall support member 4a 'each have a link pin hole 4c for connecting the lower link 6. In addition, the first wall support member 4a and the second wall support member 4a 'allow for connection pins (not shown) to be inserted corresponding to the connection ports 5b and 5c of the holder member 5, respectively. 4e).

As shown in FIG. 3, a lower shielding plate 4b is provided between the lower end of the first wall supporting member 4a and the second wall supporting member 4a 'so as to cross the lower end, and the lower shielding plate portion ( 4b) provides a means for shielding the arc further below the lower shield plate (see symbol 3 in FIG. 2). The first wall support member 4a, the second wall support member 4a ', and the lower shielding plate portion 4b may be formed of a synthetic resin material, and may be manufactured by molding by one mold.

The fixed contactor 1 may be electrically connected to a power supply or a load side, and a total of three fixed circuit breakers may be provided for the three-phase wiring breaker according to the three phases of alternating current, for example, R phase, S phase, and T phase. According to the preferred embodiment according to the first movable contact pairs (2a) and the second movable contact pairs (2b) provided for each phase, the fixed contactor (1) is a total of 12 in the case of three-phase circuit breaker four by four phases have. The circuit breaker according to the present invention, which is mainly used for industrial purposes, may be composed of a three-phase (circuit) circuit breaker or a four-pole wiring circuit breaker further including a ground phase (N pole). Thus, the fixed contactor 1 may include a pole ( There may be a total of 12 or 16, 4 each. As can be seen in FIG. 6, the fixed contactor 1 has a contact 1a corresponding to the contacts 2a-2 and 2b-2 of the movable contact 2.

An arc runner 1b may be provided to be connected to the contact 1a of the fixed contactor 1, and the arc runner 1b may include a movable contactor 2 from the fixed contactor 1 during energization of a large current. When disconnected, it performs a function of inducing an arc generated between the contacts 2a-2 and 2b-2 of the movable contactor 2 and the contact 1a of the fixed contactor 1 to move toward the arc extinguishing chamber C side. .

The lower enclosure 40 is insulated from each other by the upper enclosure 20 and the movable contactor 2, the fixed contactor 1, and the holders 4, 5, and 8, which are provided three by three in the case of the above-described three-phase circuit breaker. It is a means of isolation. To this end, the lower enclosure 40 may be manufactured by casting a synthetic resin material having electrical insulation, and has partition walls formed to protrude upward from the bottom surface for phase isolation. The upper enclosure 20 has a plurality of partitions which are formed to extend downward with a number and a horizontal position corresponding to the partitions of the lower enclosure 40.

Meanwhile, the operation of the circuit breaker according to the preferred embodiment of the present invention configured as described above will be described with reference to FIGS. 6 to 9.

First, the closing operation, that is, the ON operation, will be described with reference to FIGS. 6 and 7.

First, the handle 32 is rotated from the position of FIG. 6 to the right (clockwise) in an OFF position, that is, from the blocking position, the handle 32 is gripped and the handle 32 as shown in FIG. Rotate counterclockwise. Here, when the handle 32 is in the OFF position, the latch 35 connected by the pin to the lever 33 rotates clockwise according to the clockwise rotation of the handle 32 and the lever 33. The reset state is restrained by the latch holder (unsigned). In this state, that is, when the latch 35 is restrained and the trip spring (not shown) is tensioned to restrain the elastic energy, the handle 32 is rotated counterclockwise as shown in FIG. 6. The upper end of the trip spring rotates counterclockwise along the supported handle 32. Therefore, the lower end of the trip spring connected to the link pin of the second link member 34 is rotated counterclockwise by the elastic restoring force of the trip spring to form a straight line with the upper end, the middle part and the lower end thereof, The link pin of the link member 34 rotates counterclockwise so that the upper and lower link members of the second link member 34 are folded. Accordingly, the upper link (see reference numeral 22b in FIG. 6) connected to the lower link member of the second link member 34 rotates clockwise. Thus, the lower link 6, connected by the link pin 7a to the upper link (see reference numeral 22b in FIG. 6), rotates counterclockwise, with the wall support connected by the connecting pin to the lower link 6. The base member 4, the holder member (refer to reference numeral 5 in FIG. 5) connected to the wall supporting member 4 by the connecting pin, and the rotation support plate 8a connected to the holder member 5 by the connecting pin are also fixed bases. Rotate counterclockwise with 8b as the point. Thereby, the movable contactor 2 supported by the rotation support plate 8a rotates counterclockwise to the position which contacts the fixed contactor 1, and will be in the state like FIG. Thus, the circuit between the power supply side and the load side is connected to a state in which current can flow.

Next, the blocking operation, that is, the blocking operation by the manual off operation and the automatic blocking (trip) operation according to the abnormal current detection will be described with reference to FIGS. 6 and 8.

First, the blocking operation by the manual off operation from the on position will be described.

From the on position where reference can be made to FIGS. 6 and 7, the handle 32 is rotated clockwise to an OFF position that is gripped and rotated to the right (clockwise). Here, the latch 35 maintains a reset state constrained by a latch holder (unsigned). In this state, that is, when the latch 35 is constrained and the trip spring (not shown) is tensioned to constrain the elastic energy, the handle 32 is rotated clockwise from the position shown in FIG. The upper end of the spring rotates clockwise along the supported handle 32. Accordingly, the lower end of the trip spring connected to the link pin of the second link member 34 is rotated clockwise by the elastic restoring force of the trip spring to form a straight line with the upper end, the middle part and the lower end, and thus the second link The link pins of the member 34 rotate clockwise so that the upper and lower link members of the second link member 34 are in an extended state. Accordingly, the upper link (see reference numeral 22b in FIG. 6) connected to the lower link member of the second link member 34 rotates counterclockwise. Thus, the lower link 6 connected by the link pin 7a to the upper link (see reference numeral 22b in FIG. 6) rotates in a clockwise direction, wherein the wall support member connected to the lower link 6 by the connecting pin (4), the holder member (refer to reference numeral 5 in FIG. 5) connected to the wall supporting member 4 by the connecting pin, and the rotation support plate 8a connected to the holder member 5 by the connecting pin are fixed bases ( Rotate clockwise with 8b) as the point. As a result, the movable contactor 2 supported by the pivot support plate 8a rotates clockwise to a position to be separated from the fixed contactor 1, thereby bringing the state as shown in FIG. Therefore, the circuit between the power supply side and the load side is cut off and the current cannot flow.

Next, the automatic shutdown (trip) operation will be described.

6 and 7, in the on state, an abnormal current (also called an accident current) such as a short-circuit current occurs in a circuit, and a trip mechanism part (not shown) composed of an electromagnet and an armature (armature) detects and opens and closes it. Trigger the instrument 30.

Then, as the latch holder releases the latch 35, the latch 35 rotates counterclockwise from the state of FIG. 6, and the trip spring contracts the elastic energy, which is contracted from the tensioned state to its original state. Accordingly, the link pin of the second link member 34 connected to the lower end of the trip spring is pulled upward while the lower end of the trip spring moves upward. The upper and lower links of the second link member 34 are then unfolded while the upper link (see reference numeral 22b in FIG. 6) connected to the lower link of the second link member 34 rotates counterclockwise. Thus, the lower link 6 connected by the link pin 7a to the upper link (see reference numeral 22b in FIG. 6) rotates in a clockwise direction, wherein the wall support member connected to the lower link 6 by the connecting pin (4), the holder member (refer to reference numeral 5 in FIG. 5) connected to the wall supporting member 4 by the connecting pin, and the rotation support plate 8a connected to the holder member 5 by the connecting pin are fixed bases ( Rotate clockwise with 8b) as the point. As a result, the movable contactor 2 supported by the pivot support plate 8a rotates clockwise to a position to be separated from the fixed contactor 1, thereby bringing the state as shown in FIG. Therefore, the circuit between the power supply side and the load side is cut off and the current cannot flow.

Meanwhile, the current-limiting operation of the circuit breaker according to the present invention will be described with reference to FIGS. 6, 7 and 9.

As shown in FIG. 7, when a large accident current such as a short-circuit current occurs in a position where the movable contactor 2 contacts the fixed contactor 1, that is, an on position, the trip mechanism senses the opening and closing as described above. Before triggering the mechanism 30 and tripping, the direction of the current flowing through the movable contactor 2 is in the right direction in FIG. 6, whereas the direction of the current flowing through the contact 1a of the fixed contactor 1 is shown in FIG. 6. Since they are opposite to each other in the leftward direction, a large repulsive force between the movable contactor 2 and the fixed contactor 1 in the same direction, that is, an electromagnetic repulsive force, is generated. The electromagnetic repulsive force is fixed contactor (1) independently corresponding to the movable contactor (2) irrespective of the transmission of the driving force through the opening and closing mechanism 30 and the link (6, 22a, 22b, 22c) and the holder (4, 5, 8) Rotate in the direction to separate from This operation is called a current-limiting operation, and the current-limiting operation is a state as shown in FIGS. 9 and 6. 9 and 6, the opening and closing mechanism 30, the links 6, 22a, 22b and 22c and the holders 4, 5 and 8 maintain the position in the on state during the current-limiting operation. You can check it.

The circuit breaker according to the present invention has a lower shielding plate that shields the arc at the lower side of the movable contactor and an rear of the arc at the upper side of the movable contactor with respect to the arc generated between the contacts in the breaking operation, tripping operation, or current-limiting operation as described above. Since the upper shielding plate is provided to shield the movement, it is possible to completely shield the rear movement of the arc in the upper and lower portions of the movable contact, thereby obtaining an effect of improving the blocking performance against a large accident current such as a short circuit current.

The circuit breaker for the circuit according to the present invention has an effect of preventing the damage or deterioration caused by the arc of the switch mechanism by blocking the path through which the arc can move from the movable contact to the link and the switch mechanism side of the upper part because the holder is composed of an electrical insulating material. Can be.

1 is a perspective view illustrating main parts of a main circuit breaker in a circuit breaker according to the present invention;

Figure 2 is a partially exploded perspective view showing the configuration of the support base and the upper shield plate for supporting the movable contactor and the movable contactor in the circuit breaker according to the present invention,

Figure 3 is a perspective view showing the appearance and configuration of the holder member and the wall holder (wall holder) in the circuit breaker according to the present invention,

Figure 4 is a partially exploded perspective view showing the appearance and configuration of the opening and closing mechanism and the shaft and the upper link and the upper enclosure in the circuit breaker according to the present invention,

Figure 5 is a partially exploded perspective view showing the appearance and configuration of the upper shielding plate and the movable contactor, the holder and the lower enclosure in the circuit breaker according to the present invention,

6 is a longitudinal cross-sectional view of the circuit breaker according to the present invention cut in the longitudinal direction in the current-limiting operation,

7 is a diagram showing the main operation state of the main part when the closing position (on position) in the circuit breaker according to the present invention,

8 is a diagram illustrating main parts operating states showing a main part state when a trip position {off position} in a circuit breaker according to the present invention;

9 is a diagram showing the main operation state of the main part when the current limiting position in the circuit breaker according to the present invention.

* Explanation of symbols on the main parts of the drawings

1: fixed contact 1a: contact

1b: arc runner

2: movable contact 2a: contact

2a: first movable contact pair 2a-1: bearing

2a-2, 2b-2: contact 2b: second movable contact pair

3: lower shield plate 3a: shield plate portion

3b: bearing part 3c: bearing hole

3d, 3d ': connecting pin

4: wall holder 4a: first wall support member

4a ': second wall support member

4b: lower shield plate portion 4c: link pin hole

4d, 4e: connecting opening

5: holder member 5a: bearing

5b, 5c: connection port

6: lower link

7: top shield 7a: link pin

7b: bearing part 7c: shielding plate part

8: support base 8a: rotation support plate

8a1: Contact connecting pin 8a2: Holder bearing

8b: fixed base

20: upper enclosure 20a: shaft support groove

20b1: first screw support 20b2: second screw support

21: shaft 21a, 21b: support end

22a: Upper link (T commercial)

22b: upper link (for S phase) 22b1: link pin connection hole

22b2: drive pin connection hole

22c: upper link (for R) 23a: first support piece

23b: second support piece 30: opening and closing mechanism

31a, 31b: Side plate 32: Handle

33: lever 34: second link member

35: latch 40: lower enclosure

C: SOHO Room

Claims (4)

A fixed contactor electrically connected to a power supply or a load side and provided for each phase of an alternating current; A movable contact provided to correspond to the fixed contactor and rotatable to an input position contacting the fixed contactor or to a blocking position separate from the fixed contactor, the movable contactor having a plurality of contacts to provide a flow path through which current is classified; An opening / closing mechanism for driving the movable contactor to the closing position or the blocking position; A shaft connected to the opening / closing mechanism and rotatable by driving the opening / closing mechanism, the shaft providing a driving force for rotating the movable contactor; A link connected to the shaft to transmit a driving force; A lower shielding plate connected to the movable contactor to be rotatable with the movable contactor and extending downward from a bottom surface of the movable contactor to shield the arc from the lower side of the movable contactor when rotating to the blocking position; A holder connected to the link and composed of an electrically insulating material to electrically insulate the link and rotate by the link to rotate the movable contactor; And An upper shielding plate configured of an electrical insulation material and connected to the link to be elevated in an upper portion of the movable contactor according to the rotation of the movable contactor, and to shield a backward movement of the arc from the upper side of the movable contactor. breaker. The method of claim 1, The link, An upper link connected to the shaft to rotate together with the rotation of the shaft; And And a lower link connected to the upper link and an upper end and connected to the holder, the lower link receiving a driving force of the shaft from the upper link to the holder. The method of claim 1, The holder, A supporting base rotatably supporting the movable contactor; A holder member connected to the support base to rotate the support base; And And a wall holder connected to the holder member and connected to the link and installed on both sides of the movable contact with the movable contactor therebetween, the wall holder being made of an electrical insulating material to insulate the link. Circuit breaker, characterized in that. The method of claim 3, And a lower shielding plate portion installed across the lower ends of the pair of wall supporting members, the lower shielding plate shielding the arc further below the lower shielding plate.

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