阅读说明：本技术 电路断路器 (Circuit breaker ) 是由 中川淳 三好伸郎 于 2019-04-05 设计创作，主要内容包括：电路断路器具有导电部件(70)、可动接触件(21)、栅格部(31)、铁芯(40)、电弧滚环(80)和永磁铁(81)。导电部件(70)在一端侧设置固定触点(71),在另一端侧设置电源侧端子(72)。可动接触件(21)设置可动触点(26)。栅格部(31)具有对在固定触点(71)和可动触点(26)之间产生的电弧进行消弧的多个栅格板(34)。铁芯(40)具有彼此相对的一对侧板部(41),在一对侧板部(41)之间配置栅格部(31)。电弧滚环(80)与导电部件(70)连接,对电弧进行驱动。永磁铁(81)在可动接触件(21)与栅格部(31)相对的方向或者一对侧板部(41)相对的方向排列极性彼此不同的N极(81a)及S极(81b)。(The circuit breaker has a conductive member (70), a movable contact (21), a grid portion (31), an iron core (40), an arc runner (80), and a permanent magnet (81). The conductive member (70) is provided with a fixed contact (71) on one end side and a power source side terminal (72) on the other end side. The movable contact (21) is provided with a movable contact (26). The grid section (31) has a plurality of grid plates (34) for extinguishing an arc generated between the fixed contact (71) and the movable contact (26). The core (40) has a pair of side plate sections (41) that face each other, and the grid section (31) is disposed between the pair of side plate sections (41). The arc runner (80) is connected to the conductive member (70) and drives an arc. The permanent magnet (81) has N poles (81a) and S poles (81b) of different polarities arranged in a direction in which the movable contact (21) and the grid section (31) face each other or in a direction in which the pair of side plate sections (41) face each other.)

1. A circuit breaker, comprising:

a conductive member having a fixed contact provided on one end side and a power source side terminal provided on the other end side;

a movable contact provided with a movable contact point facing the fixed contact point;

a grid section having a plurality of grid plates for extinguishing an arc generated between the fixed contact and the movable contact;

a core having a pair of side plate portions facing each other, the grid portion being disposed between the pair of side plate portions;

an arc runner connected to the conductive member and configured to drive the arc; and

and a permanent magnet in which 2 magnetic poles having different polarities are arranged in a direction in which the movable contact faces the grid portion or in a direction in which the pair of side plate portions face each other.

2. The circuit breaker of claim 1,

the core is disposed between the grid portion and the power source side terminal, and has a region having an opening in a portion thereof.

3. The circuit breaker according to claim 1 or 2,

the permanent magnets are arranged in a direction facing the grid portion, and are arranged below the arc runner, with 2 magnetic poles having different polarities from each other, and with a direction from the movable contact toward the fixed contact set to be downward.

4. The circuit breaker of claim 2,

the iron core has:

a 1 st split core having one of the pair of side plate portions and a 1 st projecting portion projecting in a direction approaching the other side plate portion from an end of the one side plate portion; and

a 2 nd split core having the other side plate portion and a 2 nd projecting portion projecting in a direction approaching the one side plate portion from an end portion of the other side plate portion,

the 1 st projecting portion and the 2 nd projecting portion are opposed to each other in an opposing direction of the pair of side plate portions,

the opening portion is formed between the 1 st projection portion and the 2 nd projection portion.

5. The circuit breaker of claim 4,

the permanent magnets are arranged in a direction in which the pair of side plate portions face each other, and are located at shorter distances from the 1 st and 2 nd protrusions than from the arc runner.

6. The circuit breaker of claim 5,

the permanent magnet is disposed in the opening.

Technical Field

The present invention relates to a circuit breaker incorporating an arc extinguishing device for extinguishing an arc generated between contacts.

Background

In recent years, with the spread of dc circuits, there is an increasing demand for reduction of copper loss by increasing the voltage of the circuits. Therefore, there is an increasing demand for a circuit breaker used in a dc circuit to have a high voltage. In order to break a high-voltage dc circuit, it is effective to increase the separation distance of the switching contacts, but the increase in the separation distance of the switching contacts leads to an increase in the size of the circuit breaker.

For this reason, for example, patent document 1 discloses a technique of providing a yoke and a permanent magnet in a circuit breaker having a plurality of magnetic grids stacked at intervals and an arc runner for guiding an arc to a wide space. The magnitude of the magnetic field acting on the arc can be increased by the yoke and the permanent magnet.

Patent document 1: japanese laid-open patent publication No. 57-180838

Disclosure of Invention

However, when the technique described in patent document 1 is applied to a circuit breaker that requires a predetermined number of times to be able to open a circuit from a small current of several tens of amperes to a large current of several thousands of amperes, if a sufficient driving force for driving an arc is obtained, the size of the circuit breaker may be increased.

The present invention has been made in view of the above circumstances, and an object thereof is to obtain a circuit breaker capable of coping with a high voltage while suppressing an increase in size.

In order to solve the above problems and achieve the object, a circuit breaker according to the present invention includes a conductive member, a movable contact, a grid portion, an iron core, an arc runner, and a permanent magnet. The conductive member has a fixed contact on one end side and a power source side terminal on the other end side. The movable contact is provided with a movable contact point opposite to the fixed contact point. The grid section includes a plurality of grid plates for extinguishing an arc generated between the fixed contact and the movable contact. The core has a pair of side plate portions facing each other, and is disposed between the pair of side plate portions. The arc runner is connected to the conductive member and drives the arc. The permanent magnet has 2 magnetic poles of different polarities arranged in a direction in which the movable contact faces the grid portion or a direction in which the pair of side plate portions face each other.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, the effect of coping with a high voltage while suppressing an increase in size is obtained.

Drawings

Fig. 1 is a side sectional view showing the whole of a circuit breaker according to embodiment 1 of the present invention.

Fig. 2 is an exploded perspective view of the arc extinguishing unit according to embodiment 1.

Fig. 3 is an external perspective view of the arc extinguishing unit according to embodiment 1.

Fig. 4 is an exploded perspective view showing the arc extinguishing device according to embodiment 1 in a state where the movable element stopper is removed.

Fig. 5 is a side view of the fixed contact according to embodiment 1.

Fig. 6 is a plan view of the fixed contact according to embodiment 1.

Fig. 7 is a plan view of the core according to embodiment 1.

Fig. 8 is a side view of the core according to embodiment 1.

Fig. 9 is a plan view of an insulating member according to embodiment 1.

Fig. 10 is a side view of an insulating member according to embodiment 1.

Fig. 11 is an external perspective view of an insulating member according to embodiment 1.

Fig. 12 is a side sectional view showing a positional relationship among the insulating member, the grid portion, the core, and the fixed contact according to embodiment 1.

Fig. 13 is a side sectional view showing a configuration of a part of the arc extinguishing unit according to embodiment 1.

Fig. 14 is a side sectional view of the grid portion and the insulating member, not shown, in the arc extinguishing unit shown in fig. 13.

Fig. 15 is a plan view showing a configuration example of a part of the arc extinguishing unit according to embodiment 1.

Fig. 16 is a plan view showing another configuration example of the arc extinguishing unit according to embodiment 1.

Fig. 17 is a plan view showing a configuration example of a part of the arc extinguishing unit of the circuit breaker according to embodiment 2 of the present invention.

Fig. 18 is a cross-sectional view showing another configuration example of the core according to embodiment 2.

Fig. 19 is a plan view showing a configuration example of a part of the arc extinguishing unit of the circuit breaker according to embodiment 3 of the present invention.

Detailed Description

Hereinafter, a circuit breaker according to an embodiment of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the embodiments.

Embodiment 1.

Fig. 1 is a side sectional view showing the whole of a circuit breaker according to embodiment 1 of the present invention. In fig. 1, a 3-dimensional orthogonal coordinate system including a Z axis that is a positive direction above the paper surface is shown for ease of explanation. The orthogonal coordinate system is also shown in other drawings used in the following description, and when only a part of the structure of the circuit breaker is illustrated, each direction of the X axis, the Y axis, and the Z axis is a state shown in fig. 1, that is, a direction in a state where the circuit breaker is assembled.

As shown in fig. 1, the circuit breaker 100 includes an insulating housing 1, a plurality of circuit breaking units 2, an opening/closing mechanism 3, and a crossbar 4. The frame 1 has a base 11 and a cover 12 each formed of an insulating material.

A plurality of circuit interrupting units 2 and opening/closing mechanism sections 3 are arranged on the base 11. The cover 12 covers the plurality of circuit interrupting units 2 and the opening/closing mechanism section 3 disposed on the base 11. A handle window hole, not shown, is formed in the cover 12, and the operation handle 27 of the opening and closing mechanism portion 3 protrudes from the handle window hole.

The plurality of circuit breaking units 2 are arranged on the base 11 at intervals. The plurality of circuit breaking units 2 have the same structure as each other. The circuit breaker units 2 are provided in accordance with the number of circuits to be opened by the circuit breaker 100. Each circuit breaking unit 2 has a movable contact 21, a movable contact holder 22, a trip device 23, a load-side conductor 24, and an arc extinguishing unit 25. The arc extinguishing unit 25 includes a fixed contact 60.

The base end of the movable contact 21 is rotatably supported by the crossbar 4, and the movable contact 26 is provided at the tip end. The fixed contact 60 has a fixed contact 71 at one end that contacts and separates from the movable contact 26, and a power supply side terminal 72 at the other end that is connected to a power supply side conductor. The trip device 23 is provided between the movable contact 21 and the load side conductor 24, and drives a trip bar, not shown, in the opening and closing mechanism portion 3 when an overcurrent flows. The trip device 23 is connected to the movable contact 21 via the movable contact holder 22.

The opening/closing mechanism 3 is disposed on the base 11, and includes, for example, a known toggle link mechanism and a known trip bar. The opening/closing mechanism 3 sets the circuit breaker 100 in a tripped state when the trip device 23 drives the trip bar.

The crossbar 4 extends in the direction in which the plurality of circuit breaking units 2 are arranged, and is attached to the base end of the movable contact 21 provided in each circuit breaking unit 2. The crossbar 4 is rotated about the axis of the crossbar 4 by the opening/closing mechanism 3. The movable contact 21 of each circuit breaking unit 2 rotates in conjunction with the rotation of the crossbar 4 by the opening/closing mechanism portion 3, and the movable contact 26 comes into contact with the fixed contact 71 or the movable contact 26 is separated from the fixed contact 71 by the rotation of the movable contact 21.

The fixed contact 71 and the movable contact 26 constitute an opening/closing contact for opening/closing an electric circuit. The movable contact 26 is brought into contact with the fixed contact 71, whereby an electric circuit is connected, and the electric circuit is closed via the power source side terminal 72 and the load side conductor 24. Further, the movable contact 26 is separated from the fixed contact 71, whereby the electric circuit is broken, and the electric circuit including the power source side terminal 72 and the load side conductor 24 is opened in the electric circuit.

The arc extinguishing unit 25 includes a fixed contact 60 and extinguishes an arc generated when the circuit is opened. Next, the arc extinguishing unit 25 will be specifically explained. Fig. 2 is an exploded perspective view of the arc extinguishing unit according to embodiment 1. Fig. 3 is an external perspective view of the arc extinguishing unit according to embodiment 1.

As shown in fig. 2 and 3, the arc suppression means 25 includes: an arc extinguishing device 30 for extinguishing an arc generated between the fixed contact 71 and the movable contact 26 at the time of disconnection; and an iron core 40, which is disposed around the arc extinguishing device 30 and is formed of a magnet. The arc suppression means 25 includes: an insulating member 50 provided to surround the arc extinguishing device 30 and insulate the arc extinguishing device 30 from the iron core 40; and a fixed contact 60 provided with a fixed contact 71 and a power supply side terminal 72.

Fig. 4 is an exploded perspective view showing the arc extinguishing device according to embodiment 1 in a state where the movable element stopper is removed. As shown in fig. 4, the arc extinguishing device 30 includes: a grid part 31 having a plurality of grid plates 34 each made of a magnetic steel plate; and a pair of support plates 32 each made of an insulating material and supporting the plurality of grid plates 34 at intervals.

Each grid plate 34 is provided with a U-shaped notch 35 on one side of the rectangular magnetic steel plate, and side leg portions 34a are formed on both sides of the notch 35. A U-shaped notch 35 is formed in a region of the grid plate 34 facing the movable contact 21, and the distal end portion of the movable contact 21 on which the movable contact 26 is provided rotates in a space formed by the U-shaped notch 35 around the crossbar 4 as a center axis.

Both end portions of each grid plate 34 are plastically deformed so as to be inserted through a through hole, not shown, formed in the support plate 32, and the caulking portion 34b at the tip end is expanded. Thereby, each grid plate 34 is held by the support plate 32. The arc extinguishing device 30 further includes a movable piece stopper 33, and a base end of the movable piece stopper 33 is rotatably supported by the pair of support plates 32. In the example shown in fig. 4, the movable element stopper 33 is removed from the arc extinguishing device 30.

Fig. 5 is a side view of the fixed contact according to embodiment 1. Fig. 6 is a plan view of the fixed contact according to embodiment 1. As shown in fig. 5 and 6, the fixed contact 60 includes: a conductive member 70 having a fixed contact 71 disposed on an upper surface thereof; an arc runner 80 disposed on the upper surface of the conductive member 70 and electrically connected to the conductive member 70; and a permanent magnet 81 disposed below the arc runner 80.

The conductive member 70 has: a 1 st circuit 73 having one end connected to the power supply side terminal 72 and extending downward in a direction toward the base 11; and a pair of 2 nd circuits 74, one end of which is connected to the other end of the 1 st circuit 73 and extends in a direction toward the movable contact 21. Further, the conductive member 70 includes: a 3 rd circuit 75 having one end connected to the other end of the pair of 2 nd circuits 74; and a 4 th circuit 76 which is continuous with one end of the 3 rd circuit 75 and extends in a direction toward the power source side terminal 72.

A fixed contact 71 is provided on the upper surface of the base end portion of the 4 th electric path 76. The 4 th circuit 76 is disposed between the pair of 2 nd circuits 74 with a space therebetween, and extends along the pair of 2 nd circuits 74.

The arc runner 80 extends in a direction from a base end disposed on the upper surface of the base end of the 4 th circuit 76 toward the bottom surface of the base 11, and then the middle portion thereof is bent and extends in a direction along the bottom surface of the base 11 and in a direction toward the power supply side terminal 72. The permanent magnet 81 is disposed below the tip of the arc runner 80 in the space portion 77 between the pair of 2 nd electric circuits 74.

The 2 nd circuit 74 has: a parallel circuit 74a having one end and the other end of the 1 st circuit 73 extending on the base 11 along the bottom surface of the base 11; and an inclined circuit 74b having one end connected to the other end of the parallel circuit 74a and extending obliquely to the bottom surface of the base 11 toward the fixed contact 71. The 2 nd circuit 74 has a connection circuit 74c which is continuous with the other end of the ramp circuit 74b and extends up to the 3 rd circuit 75.

As described above, the fixed contactor 60 includes the arc runner 80, the arc runner 80 is disposed on the upper surface of the conductive member 70 provided to the fixed contact 71 and the load-side conductor 24, and the permanent magnet 81 is disposed below the arc runner 80.

Next, the structure of the core 40 will be explained. Fig. 7 is a plan view of the core according to embodiment 1. Fig. 8 is a side view of the core according to embodiment 1. As shown in fig. 7, the core 40 includes a pair of side plate portions 41 and a shield portion 42 connecting one ends of the pair of side plate portions 41, and is formed of a magnet.

The shield portion 42 is provided between the 1 st circuit 73 and the arc runner 80 so as to cover the fixed contact 71 side of the 1 st circuit 73. The shield 42 shields the magnetic field generated around the arc runner 80 by the current flowing through the 1 st circuit 73.

The pair of side plates 41 are disposed above the parallel circuit 74a, and have an action of concentrating magnetic flux generated by the current flowing through the parallel circuit 74a on the pair of side plates 41 and reducing the magnetic field in the vicinity of the arc runner 80.

Next, the structure of the insulating member 50 will be explained. Fig. 9 is a plan view of an insulating member according to embodiment 1. Fig. 10 is a side view of an insulating member according to embodiment 1. Fig. 11 is an external perspective view of an insulating member according to embodiment 1. Fig. 12 is a side sectional view showing a positional relationship among the insulating member, the grid portion, the core, and the fixed contact according to embodiment 1.

As shown in fig. 9 and 11, the insulating member 50 includes: a pair of side portions 51 opposing each other; and a pair of cover portions 52 that are continuous with the bottom surface side end portions of the base 11 in the corresponding side portions 51 of the pair of side portions 51 and extend along the bottom surface of the base 11, respectively.

The pair of side portions 51 are disposed between the pair of side plate portions 41 and the arc extinguishing device 30, respectively, and insulate the pair of side plate portions 41 from the arc extinguishing device 30, respectively. The pair of cover portions 52 are disposed between the 2 nd circuit 74 of the conductive member 70 and the grid portion 31 of the arc extinguishing device 30, and cover the arc extinguishing device 30 so that the 2 nd circuit 74 is not exposed on the grid portion 31 side.

As shown in fig. 10, the insulating member 50 has a shield cover 53 that connects the ends of the pair of side portions 51 on the power supply side terminal 72 side. As shown in fig. 12, the shield cover 53 is disposed between the shield portion 42 of the core 40 and the grid portion 31, and covers the grid portion 31 so that the shield portion 42 of the core 40 is not exposed on the grid portion 31 side. As shown in fig. 12, the arc runner 80 is attached to the conductive member 70 by a conductive screw 78 or the like, and thereby electrically connected to the conductive member 70.

Next, an operation of extinguishing an arc generated between the fixed contact 71 and the movable contact 26 in the arc extinguishing unit 25 will be described. Fig. 13 is a side sectional view showing a configuration of a part of the arc extinguishing unit according to embodiment 1. Fig. 14 is a side sectional view of the grid portion and the insulating member, not shown, in the arc extinguishing unit shown in fig. 13. Fig. 15 is a plan view showing a configuration example of a part of the arc extinguishing unit according to embodiment 1. In fig. 13 and 14, the support plate 32 and the movable element stopper 33 in the grid portion 31 are not shown.

When the movable contact 26 starts to separate from the fixed contact 71 by the opening operation or the trip operation of the opening/closing mechanism unit 3 from the state shown in fig. 13 and 14, an arc, which is a conductive gas, is generated between the fixed contact 71 and the movable contact 26.

The permanent magnet 81 has an N-pole 81a and an S-pole 81b, the N-pole 81a being disposed on the fixed contact 71 side, and the S-pole 81b being disposed on the power source side terminal 72 side. The orientation 92 of the magnetic field is as shown in fig. 15. That is, the magnetic field passes from the N-pole 81a through the arc runner 80 and the 4 th electric path 76, passes from the arc runner 80 and the 4 th electric path 76 through the gap toward the pair of side plates 41 in the core 40, and passes through the shield 42 of the core 40 to return to the S-pole 81 b.

Since the movable contact 26 and the fixed contact 71 face each other in the Z-axis direction, the direction 91 in which the current flows is the Z-axis negative direction as shown in fig. 15.

As described above, since the direction 91 of the current flow and the direction 92 of the magnetic field are determined, the driving direction 93, which is the direction in which the arc is driven, is the direction shown in fig. 15 according to the fleming's left-hand rule.

In the arc-extinguishing unit 25 according to embodiment 1, the permanent magnet 81 is disposed so as to increase the magnitude of the magnetic field acting on the arc, and the grid portion 31 is disposed between the pair of side plate portions 41 of the core 40. This can concentrate the magnetic flux inside the core 40. Therefore, the arc can be efficiently driven to the grid portion 31, and the arc can be maintained in the grid portion 31 to be extinguished.

In the arc extinguishing unit 25, since the permanent magnet 81 is disposed below the arc runner 80, the arc does not directly hit the permanent magnet 81. Therefore, thermal demagnetization by an arc can be suppressed in the permanent magnet 81, and a reduction in the driving force of the arc generated by the grid portion 31 due to the thermal demagnetization can be suppressed.

In the above example, the permanent magnet 81 is configured to be positioned below the front end of the arc runner 80, but the position of the permanent magnet 81 may be configured to be positioned below the middle portion of the arc runner 80. Fig. 16 is a plan view showing another configuration example of the arc extinguishing unit according to embodiment 1.

As shown in fig. 16, when the position of the permanent magnet 81 is located below the middle portion of the arc runner 80 in the extending direction, the grid portion 31 is disposed between the pair of side plate portions 41 of the core 40, and therefore the magnetic flux can be concentrated inside the core 40. Therefore, the arc can be efficiently driven to the grid portion 31, and the arc can be maintained in the grid portion 31 to be extinguished.

Further, by disposing the permanent magnet 81 below the middle portion of the arc runner 80, the magnetic field acting on the arc can be increased as compared with the case where the permanent magnet 81 is disposed below the tip end of the arc runner 80. This can reduce the consumption of movable contact 26 and fixed contact 71 during disconnection. Further, since the permanent magnet 81 does not directly contact the arc, thermal demagnetization by the arc can be suppressed in the permanent magnet 81. Therefore, a decrease in the driving force of the arc generated by the grid portion 31 can be suppressed.

As described above, the circuit breaker 100 according to embodiment 1 includes the conductive member 70, the movable contact 21, the grid portion 31, the iron core 40, the arc runner 80, and the permanent magnet 81. The conductive member 70 has a fixed contact 71 on one end side and a power source side terminal 72 on the other end side. The movable contact 21 is provided with a movable contact 26 opposed to the fixed contact 71. The grid portion 31 includes a plurality of grid plates 34 that extinguish an arc generated between the fixed contact 71 and the movable contact 26. The core 40 has a pair of side plates 41 facing each other, and the grid portion 31 is disposed between the pair of side plates 41. The arc runner 80 is connected to the conductive member 70 and drives an arc. The permanent magnet 81 has N poles 81a and S poles 81b of 2 magnetic poles having different polarities arranged in a direction in which the movable contact 21 faces the grid portion 31. This can concentrate magnetic flux inside the core 40, and therefore, the arc can be efficiently driven toward the grid portion 31, and the arc can be maintained in the grid portion 31 and extinguished. Therefore, the circuit breaker 100 can cope with a high voltage while suppressing an increase in size.

The permanent magnet 81 is disposed below the arc runner 80, with the direction from the movable contact 26 toward the fixed contact 71 being downward. This can suppress thermal demagnetization by the arc in the permanent magnet 81, and thus can suppress a decrease in the driving force of the arc generated by the arc extinguishing device 30.

Embodiment 2.

The arc extinguishing unit according to embodiment 2 is different from the arc extinguishing unit 25 according to embodiment 1 in that the core is not divided in that the core is formed by dividing 2 cores so that a part of the core disposed between the grid portion and the power source side terminal has an opening. Hereinafter, the same components as those of the arc extinguishing means 25 according to embodiment 1 are denoted by the same reference numerals, and description thereof will be omitted, and mainly the components different from those of the arc extinguishing means 25 according to embodiment 1 will be described.

Fig. 17 is a plan view showing a configuration example of a part of the arc extinguishing unit of the circuit breaker according to embodiment 2 of the present invention. As shown in fig. 17, the arc extinguishing unit 25A of the circuit breaker 100A according to embodiment 2 is different from the arc extinguishing unit 25 of the circuit breaker 100 according to embodiment 1 in that an iron core 40A is provided instead of the iron core 40. The circuit breaker 100A is similar to the circuit breaker 100 except for the arc extinguishing unit 25A, and illustration thereof is omitted.

The core 40A has a 1 st split core 43a and a 2 nd split core 43 b. The 1 st segment core 43a includes: a side plate portion 41 a; and a 1 st projecting portion 42a projecting in the X-axis positive direction, which is a direction approaching the 2 nd split core 43b from the end of the side plate portion 41 a. Similarly, the 2 nd segment core 43b includes: a side plate portion 41 b; and a 2 nd projecting portion 42b projecting in the X-axis negative direction, which is a direction approaching the 1 st divided core 43a from the end of the side plate portion 41 b.

The pair of side plates 41a and 41b have the same configuration as the pair of side plates 41 according to embodiment 1. That is, the pair of side plates 41a and 41b face each other, and the grid portion 31 is disposed between the pair of side plates 41a and 41 b.

The 1 st projecting portion 42a and the 2 nd projecting portion 42b are opposed to each other in the opposing direction of the pair of side plate portions 41a, 41b, and are arranged between the grid portion 31 and the power supply side terminal 72. The 1 st projection 42a and the 2 nd projection 42b have a function of shielding a magnetic field generated around the arc runner 80 by a current flowing through the 1 st circuit 73, similarly to the shield 42. In addition, the opening 44 is formed between the 1 st projection 42a and the 2 nd projection 42b, whereby an excessive pressure rise in the interior of the circuit breaker 100A can be prevented.

When the current-carrying circuit is in a short-circuited state due to some cause while the circuit breaker 100A is being carried on, the trip device 23 shown in fig. 1 acts on the opening/closing mechanism portion 3 to place the movable contact 21 in a tripped state. At this time, a current of several thousand amperes sometimes flows in the circuit. When the circuit is broken with a current of several thousand amperes flowing, the magnitude of the magnetic field formed by the arc is sufficiently large, and therefore the arc is driven up to the arc extinction device 30 without using the magnetic field of the permanent magnet 81.

If the arc is blocked in the region surrounded by the iron core 40A and an excessive pressure rise occurs inside the circuit breaker 100A, there is a possibility that the iron core 40A is deformed due to the strength of the iron core 40A and the housing 1 is damaged due to the strength of the housing 1. In the arc-extinguishing unit 25A, the opening 44 is formed between the 1 st projecting portion 42a and the 2 nd projecting portion 42b, so that occurrence of excessive pressure rise in the interior of the circuit breaker 100A can be prevented with high accuracy.

The core 40A is formed of the 1 st and 2 nd divided cores 43a and 43b, but is not limited to the example shown in fig. 17 as long as the opening 44 is formed to prevent a pressure increase. Fig. 18 is a cross-sectional view showing another configuration example of the core according to embodiment 2. The core 40A shown in fig. 18 includes: a pair of side plates 41a and 41 b; and a shield portion 42A connecting an end of the side plate portion 41a and an end of the side plate portion 41 b. The shield 42A is formed with an opening 44 as a through hole. The shield portion 42A has the same function as the shield portion 42.

The opening 44 formed in the shield portion 42A is formed by a circular hole, but the shape of the opening 44 is not limited to the circular hole. In addition, the number of the openings 44 may be 2 or more. In the case where a plurality of openings 44 are formed in the shield portion 42A, the shapes of the openings 44 may be different from each other.

As described above, the iron core 40A of the arc extinguishing unit 25A according to embodiment 2 is disposed between the grid portion 31 and the power supply side terminal 72, and has a region having the opening 44 in a part thereof. This can accurately prevent the occurrence of an excessive pressure rise inside the circuit breaker 100A.

The core 40A includes a 1 st split core 43a and a 2 nd split core 43 b. The 1 st segment core 43a includes: a side plate portion 41 a; and a 1 st projecting portion 42a projecting in a direction approaching the side plate portion 41b from the end portion of the side plate portion 41 a. The 2 nd split core 43b includes: a side plate portion 41 b; and a 2 nd projecting portion 42b projecting in a direction approaching the side plate portion 41a from an end portion of the side plate portion 41 b. The 1 st projecting portion 42a and the 2 nd projecting portion 42b are opposed to each other in the opposing direction of the pair of side plate portions 41a, 41 b. An opening portion 44 is formed between the 1 st projecting portion 42a and the 2 nd projecting portion 42 b. This can form the opening 44 for preventing an excessive pressure rise in the circuit breaker 100A.

Embodiment 3.

The arc extinguishing means according to embodiment 3 differs from the arc extinguishing means 25A according to embodiment 2 in the position of the permanent magnet and the orientation of the magnetic pole. Hereinafter, the same components as those of arc extinguishing means 25A according to embodiment 2 are denoted by the same reference numerals, and description thereof is omitted, and the components different from arc extinguishing means 25A according to embodiment 2 will be mainly described.

Fig. 19 is a plan view showing a configuration example of a part of the arc extinguishing unit of the circuit breaker according to embodiment 3 of the present invention. As shown in fig. 19, in the arc extinguishing unit 25B of the circuit breaker 100B according to embodiment 3, the permanent magnet 81 is disposed in the opening 44 formed between the 1 st divided core 43a and the 2 nd divided core 43B.

Further, the arc extinguishing unit 25B has N poles 81a and S poles 81B arranged in a direction in which the side plate portions 41a and 41B face each other. That is, the N pole 81a faces the 1 st protruding portion 42a of the 1 st divided core 43a via a gap, and the S pole 81b faces the 2 nd protruding portion 42b of the 2 nd divided core 43b via a gap.

Here, the shortest distance between the N-pole 81a of the permanent magnet 81 and the 1 st division core 43a is defined as "D1", the shortest distance between the S-pole 81b of the permanent magnet 81 and the 2 nd division core 43b is defined as "D2", and the shortest distance between the arc runner 80 and the permanent magnet 81 is defined as "D3". In the arc-extinguishing unit 25B according to embodiment 3, the permanent magnet 81 is disposed so as to satisfy D1 < D3 and D2 < D3. As described above, by disposing the permanent magnet 81, the direction 92 of the magnetic field becomes counterclockwise on the paper surface as shown in fig. 19.

Since the movable contact 26 and the fixed contact 71 face each other in the Z-axis direction, the direction 91 in which the current flows is the Z-axis negative direction as shown in fig. 19.

As described above, since the direction 91 of the current flow and the direction 92 of the magnetic field are determined, the driving direction 93, which is the direction in which the arc is driven according to the fleming's left-hand rule, is the direction shown in fig. 19. That is, the arc is driven in a direction from the movable contact 26 and the fixed contact 71 toward the arc extinguishing device 30.

Since the arc runner 80 serves as a drive circuit for the arc, the arc runner 80 may be consumed depending on the magnitude of the current at the time of the interruption, and the magnetic force may change depending on the change in the magnetic resistance value of the arc runner 80. In the arc-extinguishing unit 25B, magnetic lines of force mainly pass through the iron core 40A according to the arrangement of the permanent magnet 81 shown in fig. 19. Since the iron core 40A is not worn due to the disconnection, the arc extinguishing unit 25B can stably apply a driving force to the arc.

As described above, in the arc extinguishing unit 25B according to embodiment 3, the N pole 81a and the S pole 81B of the permanent magnet 81 are aligned in the X axis direction, which is the direction in which the pair of side plate portions 41a and 41B face each other. Further, the distances D1, D2 of the permanent magnet 81 from the 1 st and 2 nd protrusions 42a, 42b are shorter than the distance D3 from the arc runner 80. Thereby, a magnetic field is formed from one of the pair of side plate portions 41a, 41b toward the other, and magnetic lines of force mainly pass through the core 40A. Therefore, the arc extinguishing means 25B can stably apply a driving force to the arc.

Further, since the permanent magnet 81 is disposed in the opening 44, the distances D1 and D2 can be shortened, and the driving force can be applied to the arc in the arc extinguishing unit 25B more stably.

The configuration described in the above embodiment is an example of the content of the present invention, and may be combined with other known techniques, and a part of the configuration may be omitted or modified without departing from the scope of the present invention.

Description of the reference numerals

1 frame, 2 circuit breaking unit, 3 opening and closing mechanism part, 4 crossbar, 11 base, 12 cover, 21 movable contact, 22 movable contact holder, 23 trip device, 24 load side conductor, 25A, 25B arc extinguishing unit, 26 movable contact, 27 operating handle, 30 arc extinguishing device, 31 grid part, 32 support plate, 33 movable piece stopper, 34 grid plate, 34a side leg part, 34B riveting part, 35 notch, 40A iron core, 41a, 41B side plate part, 42A shielding part, 42A 1 st projecting part, 42B 2 nd projecting part, 43a 1 st divided iron core, 43B 2 nd divided iron core, 44 opening part, 50 insulating part, 51 side part, 52 cover part, 53 shielding part cover, 60 fixed contact, 70, 71 fixed contact, 72 power supply side terminal, 73 1 st circuit, 74 nd 2 circuit, 74a parallel circuit, 74B inclined circuit, 74c connecting circuit, 75 rd circuit, 3 th circuit, 76 th circuit, 77 space, 78 screw, 80 arc rolling ring, 81 permanent magnet, 81a N pole, 81B S pole, 91 current flowing direction, 92 magnetic field direction, 93 driving direction, 100A, 100B circuit breaker, D1, D2, D3 distance.