JP2022165074A - circuit breaker - Google Patents

Abstract

To provide a circuit breaker capable of preventing adhesion of soot, grids, and molten metal to a tripping device while suppressing an excessive pressure rise in an arc-extinguishing space.SOLUTION: A circuit breaker includes an opening/closing unit having a fixed contact and a movable contact, a tripping device that performs a trip operation to separate the movable contact in contact with the fixed contact from the fixed contact, a housing that houses the opening/closing unit and the tripping device, and a barrier 8 provided between the opening/closing unit and the tripping device inside the housing. The barrier 8 includes a first barrier 8a and a second barrier 8b provided closer to the opening/closing unit than the first barrier 8a, the first barrier 8a is formed with a first hole 8c penetrating a surface facing the opening/closing unit and a surface facing the tripping device, the second barrier 8b is formed with a second hole 8d penetrating the surface facing the opening/closing unit and the surface facing the tripping device, and the first hole 8c and the second hole 8d are formed at mutually displaced positions.SELECTED DRAWING: Figure 7

Description

FIELD OF THE DISCLOSURE The present disclosure relates to a circuit breaker that interrupts an electrical circuit by a tripping action.

A circuit breaker is provided with an opening/closing unit having contacts for breaking an electric circuit inside a housing, and a tripping device for causing the contacts to perform a trip operation. The interior of the housing is partitioned into an arc-extinguishing space in which the switch is accommodated and a relay space in which the trip is accommodated by a barrier provided between the switch and the trip.

When the electric circuit is interrupted, an arc is generated at the contact, but the arc extinguishing space partitioned by the barrier becomes high voltage due to the heat of the arc, extinguishing the arc. In order to extinguish the arc, it is necessary to increase the pressure in the arc-extinguishing space.

In the circuit breaker disclosed in Patent Document 1, by forming a hole in the barrier, when the pressure in the arc-extinguishing space rises, part of the air in the arc-extinguishing space can be discharged to the relay space through the hole. Prevents excessive pressure build-up.

JP 2012-89376 A

When the electric circuit is interrupted, soot and grid are generated in the arc-extinguishing space from the surrounding insulating members due to temperature rise due to arc generation. In addition, a metal melt, which is a melted contact point or the like, is generated in the arc-extinguishing space due to the temperature rise caused by the generation of the arc. In the circuit breaker disclosed in US Pat. No. 5,400,400, soot, grids, and molten metal can be blown and adhered to the tripping device through holes formed in the barrier. Soot, grid and metal melt deposits can lead to subsequent malfunction of the trip device.

The present disclosure has been made in view of the above, and provides a circuit that can prevent adhesion of soot, grids, and molten metal to the trip device while suppressing excessive pressure rise in the arc extinguishing space. The purpose is to obtain a circuit breaker.

In order to solve the above-described problems and achieve the object, the circuit breaker according to the present disclosure includes a fixed contact, and a movable contact provided movably between a position in contact with the fixed contact and a position separated from the fixed contact. and a switching unit having, a tripping device that performs a trip operation to separate the movable contact that is in contact with the fixed contact from the fixed contact, a housing that houses the switching unit and the tripping device, and an interior of the housing and a barrier provided between the opening and closing part and the trip device. The barrier has a first barrier and a second barrier provided closer to the opening/closing part than the first barrier. The first barrier has a surface facing the opening/closing part and a surface facing the tripping device. A first hole is formed through the second barrier, and a second hole is formed through a surface facing the opening/closing part and a surface facing the tripping device in the second barrier, and the first hole and the second hole are formed at mutually shifted positions.

According to the present disclosure, it is possible to obtain a circuit breaker that can prevent adhesion of soot, grids, and molten metal to the trip device while suppressing an excessive pressure rise in the arc-extinguishing space. Play.

A top view of the circuit breaker according to the first embodiment Side view of the circuit breaker according to the first embodiment Cross-sectional view along the III-III line shown in FIG. FIG. 2 is a perspective view of a base according to Embodiment 1; FIG. 4 is a perspective view of the base according to Embodiment 1, showing a state in which the barrier is assembled; 1 is a perspective view of a first barrier and a second barrier according to Embodiment 1; FIG. Front view of barrier for L pole in Embodiment 1 FIG. 8 is a perspective view of the barrier shown in FIG. 7; Front view of barrier for R pole in Embodiment 1 FIG. 10 is a perspective view of the barrier shown in FIG. 9; FIG. 4 is a top view showing a state where the barrier is assembled to the base according to Embodiment 1; Partially enlarged view of C part shown in FIG. Sectional view along line XIII-XIII shown in FIG. Partially enlarged view of part D shown in FIG.

A circuit breaker according to the present disclosure will be described in detail below with reference to the drawings.

Embodiment 1.
FIG. 1 is a top view of a circuit breaker according to Embodiment 1. FIG. FIG. 2 is a side view of the circuit breaker according to Embodiment 1. FIG. FIG. 3 is a cross-sectional view taken along line III-III shown in FIG.

Circuit breaker 100 includes housing 30 . The housing 30 has a base 4 made of an insulating material and a cover 5 made of an insulating material. The base 4 and the cover 5 form a space inside the housing 30 for accommodating an opening/closing part, etc., which will be described later. In the following description, the direction from the base 4 to the cover 5 is defined as upward, and the direction from the cover 5 to the base 4 is defined as downward. Also, this vertical direction does not define the installation posture of the circuit breaker 100 .

A number of circuit breaking units corresponding to the number of poles connected to the electric line are arranged in parallel on the base 4 . For example, if the circuit connected to the electric line has three phases, three circuit breaking units are arranged on the base 4 . An opening/closing mechanism having a known toggle link mechanism (not shown) is arranged above the circuit breaking unit arranged in the center among the circuit breaking units arranged in parallel.

The cover 5 covers the circuit breaker unit on the base 4 and the opening/closing mechanism. An operating handle 9 for operating the opening/closing mechanism protrudes from the cover 5 .

Each phase circuit breaking unit includes a power supply terminal 10 provided on the base 4, a fixed contact 2 extending from the power supply terminal 10, a position in contact with the fixed contact 2 and a position away from the fixed contact 2. a movable contact 1 provided at one end of which the movable contact 3 is provided so as to be rotatable; It has a disconnecting device 12 and a load side terminal 13 connected to the disconnecting device 12 and provided on the base 4 .

The movable contact 3 is provided at one end of the movable contact 1 that is rotatably held, so that the movable contact 3 moves with the rotation of the movable contact 1 and moves away from the fixed contact 2 and the position in contact with the fixed contact 2 . Move between positions. The fixed contact 2 and the movable contact 3 form an opening/closing portion 31 for opening/closing the electric circuit. When the movable contact 3 contacts the fixed contact 2, the electric circuit between the power supply terminal 10 and the load terminal 13 is turned on. When the movable contact 3 is separated from the fixed contact 2, the electric circuit between the power supply side terminal 10 and the load side terminal 13 is turned off.

A crossbar 6 is arranged at the bottom of the base 4 and extends perpendicular to the paper plane of FIGS. The crossbar 6 is rotatable about an axis, and the axis extends perpendicular to the planes of FIGS. 2 and 3 . The crossbar 6 is rotated about its axis by the opening/closing mechanism. The crossbar 6 is connected to the movable contactor 1 of each phase, and rotates the movable contactor 1 of each phase in conjunction with its own rotation. That is, when the crossbar 6 rotates around its axis, the movable contactors 1 of the circuit breaker units for each phase are simultaneously rotated, and the rotation of the movable contactors 1 turns on the electric circuit. and off. The opening/closing mechanism has a trip bar 15 driven by a trip device 12 .

The tripping device 12 is a device that drives the trip bar 15 to forcibly separate the movable contact 3 from the fixed contact 2 when an overcurrent flows through the electric circuit of the circuit breaker 100 . The tripping device 12 has an electromagnetic tripping device 16 and a thermal tripping device 17 .

The electromagnetic tripping device 16 has a fixed core 16 a and an armature 7 . The fixed core 16a generates a magnetic force to attract a magnetic body when an overcurrent flows. The armature 7 is made of a magnetic material and rotatably supported by a shaft 16b. One end of the armature 7 serves as an attracted portion 7a that is attracted to the fixed iron core 16a. The other end of the armature 7 serves as an action portion 7b that contacts the trip bar 15 and drives the trip bar 15 when the attracted portion 7a is attracted to the fixed iron core 16a. Although not shown, a spring is also provided for returning the armature 7 to a state in which the attracted portion 7a is separated from the state in which it is attracted to the fixed core 16a.

When an overcurrent flows through the electrical circuit of the circuit breaker 100, the attracted portion 7a of the armature 7 is attracted to the fixed iron core 16a, and the acting portion 7b drives the trip bar 15 against the biasing force of the spring. A trip operation is performed in which the crossbar 6 and the movable contact 1 are rotated to separate the movable contact 3 from the fixed contact 2 . As a result, the electric path provided with the circuit breaker 100 is cut off instantly.

The thermal tripping device 17 includes a heater 17a and a bimetal 17b fixed to the fixed iron core 16a with the heater 17a interposed therebetween. The bimetal 17b is deformed by its own temperature rising when an overcurrent flows. The bimetal 17b contacts the trip bar 15 by deformation and drives the trip bar 15. As shown in FIG. By driving the trip bar 15, the crossbar 6 and the movable contactor 1 are rotated to perform a trip operation in which the movable contact 3 is separated from the fixed contact 2. FIG. As a result, the electric path provided with the circuit breaker 100 is cut off instantly.

An arc is generated between the fixed contact 2 and the movable contact 3 when an overcurrent flows and the electric circuit is interrupted. An arc-extinguishing device 14 is provided near the fixed contact 2 and the movable contact 3 . The arc-extinguishing device 14 has an arc-extinguishing insulating material molded body. When an arc is generated between the fixed contact 2 and the movable contact 3, the arc-extinguishing insulating material molded body is decomposed to generate gas, the generated gas cools the arc, and the generated gas is sprayed to extinguish the arc. It contributes to quick extinguishing of the arc by elongation or the like.

As shown in FIG. 3 , a barrier 8 is provided between the opening/closing section 31 and the tripping device 12 . An arc extinguishing space 18 and a relay space 19 partitioned by a barrier 8 are formed inside the housing 30 . The arc-extinguishing space 18 is a space in which the opening/closing part 31 and the arc-extinguishing device 14 are provided. A relay space 19 is a space in which the tripping device 12 is provided.

The barrier 8 has a first barrier 8a and a second barrier 8b. The second barrier 8b is provided closer to the opening/closing part 31 than the first barrier 8a. 4 is a perspective view of a base according to Embodiment 1. FIG. FIG. 5 is a perspective view of the base according to Embodiment 1, showing a state in which the barrier is assembled. The base 4 is formed with a groove 4a into which the barrier can be inserted.

FIG. 6 is a perspective view of a first barrier and a second barrier according to Embodiment 1. FIG. Two protrusions 8f are formed on the upper end of the first barrier 8a so as to protrude toward the second barrier 8b. The first barrier 8a is formed with ribs 8e protruding sideways. A first hole 8c is formed in the first barrier 8a so as to pass through the surface facing the opening/closing part 31 and the surface facing the tripping device 12 .

A convex portion 8g that protrudes upward is formed on the upper end of the second barrier 8b. The second barrier 8b is formed with a second hole 8d penetrating the surface facing the opening/closing part 31 and the surface facing the tripping device 12 .

When the first barrier 8a and the second barrier 8b are combined, the projections 8g of the second barrier 8b fit between the projections 8f of the first barrier 8a. Thus, in addition to fixing by the groove 4a formed in the base 4, the first barrier 8a and the second barrier 8b are positioned by the engagement between the projection 8f and the projection 8g.

With the first barrier 8a and the second barrier 8b assembled to the base 4, there is a gap between the surface in which the first hole 8c is formed and the surface in which the second hole 8d is formed. be provided.

The electrical circuit of the circuit breaker unit arranged in the center among the circuit breaker units arranged in parallel and the circuit breaker 100 connected thereto is called a C pole. Also, the electric circuit of the circuit breaker unit arranged on one side of the C pole and the circuit breaker 100 connected thereto is called the R pole. Also, the electric circuit of the circuit breaker unit arranged on one side of the C pole and the circuit breaker 100 connected thereto is called the L pole.

At positions corresponding to the L pole and R pole of the cover 5, internal accessory storage chambers 5a are provided for storing internal accessory devices such as auxiliary switches and alarm switches. The first barrier 8a and the second barrier 8b are provided so as to be close to or in contact with the bottom surface of the internal accessory storage chamber 5a. The bottom surface of the internal accessory storage chamber 5 a forms part of the wall surface surrounding the arc extinguishing space 18 and the relay space 19 . Further, the phase partition walls provided between the respective phases of the R pole, L pole, and C pole also form part of the walls surrounding the arc extinguishing space 18 and the relay space 19 .

In addition, although the above was explained in the case of a circuit breaker, in the case of an earth leakage breaker, the L pole or R
An earth leakage detector is arranged in place of the internal accessory storage chamber 5a of either one of the poles.

7 is a front view of the barrier for the L pole in Embodiment 1. FIG. 8 is a perspective view of the barrier shown in FIG. 7; FIG. 9 is a front view of the barrier for the R pole in Embodiment 1. FIG. 10 is a perspective view of the barrier shown in FIG. 9. FIG. 11 is a top view showing a state in which a barrier is attached to a base according to Embodiment 1. FIG. FIG. 12 is a partially enlarged view of the portion C shown in FIG. 11. FIG. FIG. 13 is a cross-sectional view taken along line XIII-XIII shown in FIG. FIG. 14 is a partially enlarged view of a portion D shown in FIG. 13. FIG.

As shown in FIGS. 7 to 10, when viewed from the front, the first hole 8c of the first barrier 8a and the second hole 8d of the second barrier 8b are formed at offset positions that do not overlap each other. there is When viewed along the direction perpendicular to the surface on which the first holes 8c are formed, the first holes 8c of the first barrier 8a and the second holes 8d of the second barrier 8b In other words, they are formed at offset positions that do not overlap each other. In the first embodiment, the first hole 8c and the second hole 8d are formed at positions that do not completely overlap, but they may be formed at positions where they partially overlap.

As shown in FIGS. 1, 2, 12, 14, etc., an exhaust port 21 is formed in a wall surface of the base 4 surrounding the relay space 19. As shown in FIG. The direction in which the first hole 8c is shifted with respect to the second hole 8d is the direction toward the exhaust port 21 .

As described above, an arc is generated by a trip operation when an overcurrent flows through the electrical circuit of the circuit breaker 100, and the pressure in the arc extinguishing space 18 increases. Since the relay space 19 separated from the arc extinguishing space 18 by the barrier 8 is maintained at a high voltage, the arc extinguishing performance can be improved.

Here, since the first hole 8c and the second hole 8d are formed in the barrier 8, part of the air in the arc extinguishing space 18 enters the relay space 19 through the first hole 8c and the second hole 8d. erupt. As a result, an excessive pressure rise in the arc extinguishing space 18 during trip operation can be prevented. Therefore, the strength required for the housing 30 can be suppressed, and the circuit breaker 100 can be miniaturized and the manufacturing cost can be suppressed.

In addition, since the first hole 8c of the first barrier 8a and the second hole 8d of the second barrier 8b are formed at offset positions so as not to overlap with each other when viewed from the front, the first hole 8c and the air ejected through the second hole 8d can be prevented from being directly blown to the tripping device 12. As shown in FIG. During the tripping operation, soot and grid are generated from the arc extinguishing device 14 due to temperature rise due to arc generation. In addition, a molten metal is also generated in which the opening/closing portion 31 is melted. The soot and the like are mixed with the air jetted through the first hole 8c and the second hole 8d and jetted into the relay space 19. can be prevented from adhering to the tripping device 12 . Therefore, it is possible to prevent malfunction caused by adhesion of soot or the like to the tripping device 12 .

Further, since the direction in which the first hole 8c is displaced from the second hole 8d is the direction toward the exhaust port 21, the air jetted through the first hole 8c and the second hole 8d is It is discharged through an exhaust port 21 along a gas flow path 20 indicated by 12 . Therefore, it is possible to prevent soot and the like mixed in the air jetted through the first hole 8c and the second hole 8d from floating in the relay space 19. FIG. As a result, adhesion of soot or the like to the tripping device 12 can be more reliably prevented. Note that the exhaust port 21 may be formed in the cover 5 or may be formed across the base 4 and the cover 5 .

Note that circuit breakers 100 with different rated currents and different breaking capacities may be configured using the same housing 30 . In that case, by changing the size of the first hole 8c and the second hole 8d according to the difference in rated current and breaking capacity, the pressure rise in the arc extinguishing space 18 when a large current is generated is optimized. Breaking performance can be ensured.

Although the shape of the first hole 8c and the second hole 8d is illustrated as being circular, they may be other shapes such as a quadrangular shape or a triangular shape. In addition, for the C pole between the L pole and the R pole, an opening/closing mechanism is usually provided, and since the components of the opening/closing mechanism function as the barrier 8, the barrier 8 is provided for the C pole. It doesn't have to be.

In addition, since all components such as the power supply terminal 10, the load terminal 13, the tripping device 12, and the barrier 8 can be assembled by inserting them into the base 4 from one direction, the assembly of the circuit breaker 100 can be easily automated. It can be carried out.

Further, since the barrier 8 is formed separately from the base 4, the sizes of the first hole 8c and the second hole 8d can be changed by replacing the barrier 8 according to the difference in rated current or breaking capacity. Since it can be easily changed, it is possible to optimize the pressure rise in the arc extinguishing space 18 when a large current is generated, and improve the breaking performance.

Even if the exhaust port 21 is not formed in the base 4, if the first hole 8c and the second hole 8d are formed at different positions, the distance from the arc extinguishing space 18 to the relay space 19 can be reduced. Since the air blowing direction can be set in a direction that avoids the tripping device 12, adhesion of soot or the like to the tripping device 12 can be suppressed.

Further, if the position where the first hole 8c is formed is outside the region connecting the second hole 8d and the tripping device 12, air is ejected from the arc extinguishing space 18 to the relay space 19. The direction can be set in a direction that avoids the tripping device 12 more reliably, so that adhesion of soot or the like to the tripping device 12 can be more reliably prevented.

Further, since the direction in which the exhaust port 21 is formed with respect to the barrier 8 differs between the R pole and the L pole, as shown in FIGS. , the direction in which the first hole 8c is shifted with respect to the second hole 8d.

The configuration shown in the above embodiment shows an example of the content of the present disclosure. The configuration of the embodiment can be combined with another known technique. Configurations of the embodiments may be combined as appropriate. A part of the configuration of the embodiment can be omitted or changed without departing from the gist of the present disclosure.

1 Movable Contact 2 Fixed Contact 3 Movable Contact 4 Base 4a Groove 5 Cover 5a Internal Accessory Storage Chamber 6 Crossbar 7 Armature 7a Adsorbed Part 7b Action Part 8 Barrier 8a First barrier, 8b second barrier, 8c first hole, 8d second hole, 8e rib, 8f protrusion, 8g protrusion, 9 operation handle, 10 power supply side terminal, 11 mover holder, 12 tripping device, 13 load side terminal 14 arc extinguishing device 15 trip bar 16 electromagnetic tripping device 16a fixed core 16b shaft 17 thermal tripping device 17a heater 17b bimetal 18 arc extinguishing space 19 relay space 20 Gas channel, 21 exhaust port, 30 housing, 31 switch, 100 circuit breaker.

Claims (3)

an opening/closing unit having a fixed contact; and a movable contact provided movably between a position in contact with the fixed contact and a position separated from the fixed contact;
a tripping device for performing a trip operation to separate the movable contact that is in contact with the fixed contact from the fixed contact;
a housing that houses the opening/closing unit and the tripping device;
a barrier provided between the opening/closing unit and the tripping device inside the housing,
The barrier has a first barrier and a second barrier provided closer to the opening/closing part than the first barrier,
The first barrier is formed with a first hole passing through a surface facing the opening/closing portion and a surface facing the tripping device,
The second barrier is formed with a second hole penetrating a surface facing the opening/closing part and a surface facing the tripping device,
A circuit breaker, wherein said first hole and said second hole are formed at positions shifted from each other. The interior of the housing is partitioned by the barrier into an arc-extinguishing space in which the opening/closing unit is accommodated and a relay space in which the tripping device is accommodated,
An exhaust port is formed in a wall surface of the housing surrounding the relay space,
2. The circuit breaker according to claim 1, wherein a direction in which said first hole is shifted with respect to said second hole is a direction toward said exhaust port. 3. The circuit breaker according to claim 1, wherein the housing is formed with a groove into which the barrier is inserted.

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