TWI550673B - Breaker - Google Patents

Description

breaker

The invention relates to a circuit breaker for interrupting an overcurrent and a short circuit current of a circuit, in particular to a circuit breaker for blocking a direct current.

As a prior art in the art, there is a patent document 1 (JP-A-2011-129385). Patent Document 1 discloses that in order to increase the arc driving force of the circuit breaker, a U-shaped magnetic body having a pair of leg portions is disposed so as to surround a fixed contact of the fixed joint, and the leg portion is located at the contact point On both sides of the arc generated therebetween, a permanent magnet is disposed on the leg of the magnetic body.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] JP-A-2011-129385

The interruption of the current in the circuit breaker is driven by an electromagnetic force. The arc is performed by an arc, and the electromagnetic force utilizes a magnetic field generated by the passage of current. For example, in the case of a DC current having a DC current of 20 A or less, the magnetic field generated by the passage of current is weak, and it is difficult to drive the arc. In addition, since there is no zero point of the alternating current, there is a problem that the interruption is difficult.

Patent Document 1 describes a technique of disposing a permanent magnet in a breaker so that a magnetic field is generated in one direction on a contact, thereby generating an electromagnetic force and driving the arc to the power supply side of the breaker. If the polarity of the current is changed, since the arc is driven on the load side and the breaking capacity is dropped, there is a problem that the energizing direction is limited.

In order to solve the above problems, for example, the configuration described in the scope of the patent application is employed. Although the present invention includes a plurality of means for solving the above problems, if one of them is used, the feature is: "A circuit breaker which is a circuit breaker for interrupting an overcurrent or a short-circuit current flowing in a circuit, and is characterized by: a fixed joint connected to the circuit and having a fixed contact; a movable joint having a movable contact disposed opposite to the fixed contact and contacting or being separated from the fixed contact; and generating between the fixed contact and the movable contact The arc extinguishing device for arc extinguishing, wherein the fixed joint forms a folded elongated protrusion, the fixed joint is disposed on an elongated protrusion of the fixed joint, and an arc is disposed on a back side of the elongated protrusion The revenue device sets a permanent magnet in the arc revenue device."

According to the present invention, in the case of a relatively small DC current corresponding to a 20A level or less, a relatively simple configuration of the permanent magnets can be arranged in the arc reciprocator to provide a DC corresponding to the energization direction of the current. Circuit breaker.

10‧‧‧Circuit breaker

11‧‧‧Power side terminal

12‧‧‧Fixed joints

13‧‧‧Fixed joints

14‧‧‧ Arc Emissions

15‧‧‧ permanent magnet

16‧‧‧ movable joints

17‧‧‧ movable joint

18‧‧‧Arc extinguishing device

19‧‧‧Opening and closing institutions (point and wire frame)

20‧‧‧Bounce device (dotted wire frame)

21, 24‧‧‧ conductor

22‧‧‧Bimetal

25‧‧‧Load side terminal

26‧‧‧movable department

27‧‧‧Rotating fulcrum of movable joint

28‧‧‧ movable iron core

29‧‧‧Fixed iron core

30‧‧‧Shell

31‧‧‧ Cover

40‧‧‧ magnetic lines

41, 42, 43, 44, 45, 46‧‧‧ The foot of the arc

51, 52, 53, 54, 55, 56‧‧‧ directions of the magnetic field

61, 62, 63, 64, 65, 66‧‧ ‧ direction of electromagnetic force

70, 71, 72, 73‧‧‧ arc

121‧‧‧Slim extension of the fixed joint

122‧‧‧punching

141‧‧‧ spacers for arc revenue devices

Fig. 1 is a cross-sectional view showing the overall configuration of a circuit breaker according to a first embodiment of the present invention.

2A is a perspective view showing the configuration of a fixed joint, a movable joint and an arc extinguishing device of the circuit breaker of FIG. 1.

2B is a perspective view showing the configuration of the fixed joint, the movable joint and the arc extinguishing device of the fixed joint of FIG. 2A and the arc accumulator 1/2.

FIG. 3A is a perspective view showing the appearance of a fixed joint.

FIG. 3B is a cross-sectional view taken along line A-A of FIG. 3A.

FIG. 3C is a cross-sectional view taken along line B-B of FIG. 3A.

[Fig. 4] A perspective view showing the appearance of an arc generator and a permanent magnet.

Fig. 5 is a view showing a magnetic field and an electromagnetic force of an arc acting on a fixed contact.

FIG. 6A is a diagram illustrating a state in which an arc generated between contacts is moved by an electromagnetic force. FIG.

FIG. 6B is a diagram illustrating a state in which an arc generated between contacts is moved by electromagnetic force. FIG.

[Fig. 7] A diagram showing the rotation of the arc between the contacts on the fixed contact.

Fig. 8 is a block diagram showing a second embodiment of the present invention.

Fig. 9 is a view showing a magnetic field and an electromagnetic force of an arc acting on a fixed contact.

Hereinafter, embodiments of the present invention will be described using the drawings.

(Example 1)

Fig. 1 is a cross-sectional view showing the overall configuration of a circuit breaker according to a first embodiment of the present invention. In Fig. 1, a 10-series circuit breaker, an 11-series power supply side terminal, a 12-series fixed joint, and a folded shape, 13 series are fixed to the fixed joint of the folded fixed joint 12, and 14 are fixed to the folded fixed joint. Arc generator, 15 series permanent magnets arranged in the arc retractor 14, 16 series movable contacts, 17 series movable joints, 18 series arc extinguishing devices for arcing between contacts, and 19 series driving The opening and closing mechanism (dotted wire frame) of the movable joint 17 that turns ON/OFF the current, and the tripping device (dotted wire frame) that drives the opening and closing mechanism 19 to open the contact point when the overcurrent or the short-circuit current flows. 21, 24 are conductors that allow current to flow, 22 are bimetals that change with temperature, 25 series load side terminals, 26 series movable parts, 27 series movable joint rotation points, 28 series movable iron cores, 29 series fixed iron cores, 30 series fixed iron cores, 30 The housing of the opening and closing mechanism, the tripping mechanism, and the like, and the cover of the 31-series housing 30 are housed.

Next, the configuration of the circuit breaker 10 will be described. In FIG. 1, the circuit breaker 10 bends the power supply side terminal into an inverted L shape, and then bends It is formed in an L shape, has a part of a flat portion, is further bent, is formed in a stepped shape to form a fixed joint 12, and is provided with a fixed joint 13. Further, an arc retractor 14 is provided at the fixed joint 12, and a permanent magnet 15 is disposed at the arc retractor 14. The configuration of the fixed joint 12 will be described in detail later.

The movable contact 16 is disposed at a position opposite to the fixed contact 13, and the movable contact 16 is provided and fixed to the movable joint 17. Further, the arc extinguishing device 18 that extinguishes the arc generated between the contacts when the current is interrupted is disposed around the movable joint 17. The movable joint 17 is connected to the flexible conductor 21, and the conductor 21 is connected to the bimetal 22 constituting the jumping device 20. The bimetal 22 is disposed nearly vertically in the casing 30, and is connected to the conductor 24 via the center portion of the bimetal 22, and the conductor 24 is connected to the load side terminal 25. The tip end of the bimetal 22 system constituting the trip device 22 is deformed by heat generated by an overcurrent, and the movable portion 26 is pressed by the deformation, and the opening and closing mechanism 19 is operated to open the contact and block the circuit.

Further, the trip device 22 is provided with a bimetal that operates the opening and closing mechanism 19 when an overcurrent flows through the circuit, and electromagnetically tripping the opening and closing mechanism 19 when the short-circuit current of the circuit flows in parallel with the bimetal 22 mechanism. The electromagnetic tripping mechanism is provided with the movable iron core 28 and the fixed iron core 29. When the short-circuit current flows, an electromagnetic force is generated, the movable iron core 28 is sucked, the movable portion 26 is pressed, the opening and closing mechanism 19 is operated, the contact is opened, and the circuit is covered. Broken.

Next, the configuration of the movable joint of the circuit breaker and the periphery of the fixed joint will be described. 2A shows a fixed joint, a movable joint, FIG. 2B is a perspective view showing the structure of the arcing device and the arc extinguishing device. FIG. 2B is a perspective view showing the portion of the fixed joint of FIG. 2A in a direction of 1/2 of the power supply and load side directions, both of which are shown as open contacts. State.

In Fig. 2A, the power supply side terminal 11 has a hole 111 for connection to a power supply line, which is bent into an inverted L shape, and then bent into an L shape to form a fixed joint 12. The configuration of the fixed joint 12 will be described in detail later. A fixed contact 13 is disposed near the center of the elongated protrusion 121 of the fixed joint 12, and a movable contact 16 is disposed at the front end of the movable joint 17 at a position opposed to the fixed contact 13, and the movable joint 17 has the hole 27 as a fulcrum. While rotating, the movable contact 16 is in contact with or away from the fixed contact 13. Further, the arc retractor 14 is disposed on the lower side of the elongated projection 121 of the fixed joint 12. Then, the spacer 141 is placed at the center portion at the arc retractor 14. Further, the arc extinguishing device 18 is disposed to surround the movable joint 17 and the periphery of the fixed joint 12. The arc extinguishing device 18 has a predetermined interval between the plurality of sheets, and is formed as a stack.

Further, in FIG. 2B, the arc retractor 14 has a concave shape, and the permanent magnet 15 is disposed on the lower side of the fixed contact 13. By thus arranging the permanent magnet 15 on the lower side of the fixed contact 13, a magnetic field is generated around the contact, and an electromagnetic force is applied to the arc generated between the contacts to drive the arc.

Next, the fixed joint and the arc income device according to the present invention will be described using Figs. 3A, 3B, and 3C. 3A is a perspective view showing the appearance of the fixed joint and the arc-increasing device, FIG. 3B is a cross-sectional view taken along line A-A of FIG. 3A, and FIG. 3C is a cross-sectional view taken along line B-B of FIG. 3A.

In FIG. 3A, the power source side terminal 11 has a hole 111 for connection to the power supply side line, is bent into an inverted L shape, and is then bent into an L shape to form a fixed joint 12. Further, the fixed joint 12 has a flat portion at a place where the bent portion is formed, and the flat portion forms an elongated protrusion 121 for the fixed contact 13 at the center from the side of the load side, and the periphery of the protrusion is formed into a U-shaped hole. The way of 122 is for punching. Then, on the portion on the load side of the U-shaped hole 122, the elongated projection 121 is bent into a step shape as it is. Therefore, the elongated protrusion 121 of the fixed joint 12 is formed in a stepped shape by being bent, and protrudes on the power supply side, and the lower side of the elongated protrusion 121 has a space due to the hole 122. In the vicinity of the center of the elongated projection 121 of the fixed joint 12, a fixed contact 13 is provided for fixing so that the position of the fixed contact 13 coincides with the movable contact 16. Further, on the back side of the elongated protrusion 121, an arc retractor 14 as shown in Fig. 4 is disposed, which will be described using Fig. 3B.

3B is a cross-sectional view taken along line A-A of FIG. 3A. In FIG. 3B, the fixed joint 12 bends the power supply side terminal 11 into an inverted L shape, and then bends into an L shape, and the flat portion is formed into a punched portion by pressing or the like, and is bent into a step shape. The elongated protrusion 121 of the fixed contact 13 is not bent, and the fixed hole contact 13 is fixed. The arc retractor 14 is disposed on the lower side of the elongated projection 121 of the fixed joint 12 to which the fixed joint 13 is fixed. The arc retractor 14 is provided with a concave shape in which the permanent magnet 15 is disposed in a concave shape immediately below the fixed contact 13, and is fixed to the elongated projection 121 of the fixed joint 12 by caulking or the like. In addition, the structure of the arc revenue device 14 is shown in FIG. 4, but is opposite to the power supply and negative configuration of the permanent magnet 15. In the carrier side direction, the spacers 141 are disposed on both sides in the right-angle direction to form a structure in which the permanent magnets 15 are covered.

Next, a cross-sectional view taken along line B-B of FIG. 3A is shown in FIG. 3C. In Fig. 3C, the arc retractor 14 is provided with permanent magnets 15 disposed immediately below the fixed contacts 13 fixed to the elongated projections 121 of the fixed joint 12, and spacers 141 are formed on both sides. In the configuration of FIG. 3C as described above, when the upper side of the magnetic pole of the permanent magnet 15 is the N pole and the lower side is the S pole, the magnetic field lines 40 are discharged from the N pole toward the S pole so as to draw a parabola. Further, the magnetic lines of force from the permanent magnet 15 are discharged from the N-pole over the entire circumference of 360 degrees, and the magnetic lines of force which are placed throughout the circumference are concentrated at the end of the metal spacer 141 of the arc-increasing device 14. Then, the magnetic lines of force such as returning to the S pole are depicted.

Next, an arc revenue device 14 relating to the present invention will be described. 4 is a perspective view showing the appearance of the arc retractor 14 and the permanent magnet 15. The arc retractor 14 has a concave shape in the direction of the power source and the load side, and the permanent magnet 15 is provided in a concave shape. The position of the pole of the permanent magnet 15 is set to be a vertical direction so that the upper side is the N pole and the lower side is the S pole. In some cases, the opposite can also be made. Further, spacers 141 are formed on both sides of the permanent magnet 15 in a direction orthogonal to the direction of the power source and the load side of the arc retractor 14. The spacer 141 is formed so as to be concentrated from the magnetic flux discharged from the N pole of the permanent magnet 15 into the end surface of the spacer 141, and passes through the arc retractor 14 to enter the S pole.

Here, in the case of the type of the permanent magnet 15, a permanent magnet is used as a permanent magnet, a ferrite magnet in which crystals of iron-containing oxide are aggregated, and a rare earth magnet mainly composed of niobium, iron, and boron. The neodymium magnet with the strongest medium magnetic force, the samarium cobalt magnet composed of yttrium and cobalt, and the alnico magnet magnetized with aluminum, nickel, cobalt, etc. as raw materials.

Then, when the closed state in which the movable contact 16 of the circuit breaker contacts the fixed contact 13 is shifted to the open state in which the two contacts are separated by the overcurrent and the short-circuit current, an arc is generated between the two contacts. In addition, the arc is cooled by the potential difference between the two contacts and by contact with the arc extinguishing device 18. In the case of an AC circuit, since there is a current zero point, the arc generated between the two contacts is arc extinguished in a short time. However, in the DC circuit, since there is no DC zero point, it is difficult for the arc to be arc-extinguished, and it may be continued for a long time or may become unblocked.

In particular, in the case of a small current range of, for example, 20A or less, since the magnetic field generated from the current flowing through the joint is small, the electromagnetic force acting on the arc itself is weak, and the arc driving force is lowered. For this reason, the arc stagnates on the joint, and the interruption becomes difficult. Therefore, in the present embodiment, the permanent magnet 15 is disposed near the lower side of the fixed contact to generate a magnetic field around the contact to drive the arc.

Next, in the configuration of the first embodiment of the present invention shown in FIGS. 2A and 2B, an arc generated by an overcurrent or the like will be described with reference to FIGS. 5 to 8. In Fig. 5, Fig. 5(a) is a view showing a state of an arc on a fixed contact, and Fig. 5(b) is a cross-sectional view taken on a center line of Fig. 5(a). Fig. 5(a) shows the direction 40 of the magnetic field on the fixed contact and the direction of the electromagnetic force applied to the arc, and the following is the case where the permanent magnet 15 is such that the side close to the fixed contact 13 is N pole and far side. In the S pole, the energizing direction flows from the movable contact 16 to the fixed contact 13. At The arc 70 generated by the movable contact and the fixed contact receives electromagnetic force due to the magnetic field of the permanent magnet 15 and the current flowing through the arc itself, and the direction follows Fleming's left-hand rule. When viewed from a fixed contact, the direction of the magnetic field is symmetrical about the centerline, depending on the position. For this reason, since the direction of the electromagnetic force acting on the arc 70 varies depending on the position, the arc 70 that is moved by the electromagnetic force moves due to the change of direction, so that the circle is moved clockwise by rotating the circle on the fixed contact. That is, in Fig. 5(a), 41 denotes the foot of the arc 70 (the point at which the arc is in contact with the fixed contact is referred to as a foot), meaning that the current flows from the surface to the back perpendicularly to the plane of the paper. Further, the direction of the magnetic field at the point of the foot 41 is in the direction of the arrow 51, and the direction in which the permanent magnet 15 directly below passes through the fixed contact 13 and radially radiates from the central angle of the fixed contact 13. The direction of the magnetic field is parabolically discharged from the N-pole of the permanent magnet and returns to the S-pole due to the direction of the magnetic field line, so that it is radially discharged in the fixed contact. Therefore, due to Fleming's left-hand rule, the electromagnetic force acts as arrow 61 and the arc 70 moves.

Next, in the case where the arc 70 moves from the foot 41 to the foot 42 due to the electromagnetic force 61, in the case of the foot 42, the direction of the current flowing through the arc 70 is perpendicular to the direction of the paper from the surface to the back, the magnetic field The direction is the downward direction as indicated by the arrow 52, so the electromagnetic force becomes the oblique upper left direction indicated by the arrow 62. Therefore, the arc 70 moves in the obliquely upper left direction. Next, in the case where the arc 70 is moved from the foot 42 by the electromagnetic force 62 to the foot 43, in the case of the foot 43, the direction of the current flowing through the arc 70 is due to the direction perpendicular to the plane from the front to the back of the sheet, the direction of the magnetic field. The direction indicated by the arrow 53 is obliquely downward left, so the electromagnetic force acts as an arrow 63 upward. to. Therefore, the arc 70 moves upward. Next, in the case where the arc 70 is moved from the foot 43 to the foot 44, in the case of the foot 44, the direction of the current flowing through the arc 70 is indicated by the arrow 54 in the direction perpendicular to the plane from the front to the back of the paper. It is inclined in the upper left direction, so the electromagnetic force acts as an arrow 64 on the oblique upper right direction. Therefore, the arc 70 moves obliquely to the upper right. Next, in the case where the arc 70 moves from the foot 44 to the foot 45, the direction of the current flowing through the arc 70 in the direction of the foot 45 is indicated by the arrow 55 in the direction perpendicular to the plane from the front to the back of the paper. In the upward direction, the electromagnetic force acts as an arrow 65 in the right direction. Therefore, the arc 70 moves to the right. Next, in the case where the arc 70 is moved from the foot 45 to the foot 46, in the case of the foot 46, the direction of the current flowing through the arc 70 is in a direction perpendicular to the plane from the front to the back of the sheet, and the direction of the magnetic field is indicated by an arrow 56. In the obliquely upper right direction, the electromagnetic force acts as an arrow 66 on the oblique lower right direction. Therefore, the arc 70 moves in the obliquely lower right direction.

Then, since the arc 70 moves from the foot 46 to the foot 41, the arc 70 continuously moves, so that it moves in a clockwise direction on the fixed contact 13.

FIG. 5(b) shows the magnetic field of the arc 70 and the permanent magnet 15. In FIG. 5(b), the arc 70 is generated between the movable contact 16 fixed to the movable joint 17 and the fixed joint 13 fixed to the fixed joint 121. The arrow shown by the arc 70 indicates the direction of the current. Further, when the upper side is the N pole and the lower side is the S pole in the permanent magnet 15 disposed in the arc retractor 14, the magnetic field lines 40 are radially drawn from the N-pole surface over the entire circumference as shown in the drawing. Parabolic and return to the S pole. In addition, if in magnetic On the way of the force line, there is a spacer 141 or the like of the arc retractor 14 as shown in FIG. 3C, and the magnetic lines of force are concentrated on the metal plate to pass therethrough.

Next, a state in which the arc 70 draws a circle between the contacts will be described with reference to FIGS. 6A and 6B. 6A illustrates the state in which the arc 71 is generated between the movable contact 16 and the fixed contact 13, the electromagnetic force acts according to the left-hand rule of Fleming, and the arc 71 moves as indicated by the arrow 80 to the position of the arc 72. Then, from the state of the arc shown in Fig. 6A, the state of the arc shown in Fig. 6B is moved. Fig. 6B shows the state in which the arc 72 of Fig. 6A moves by the action of the electromagnetic force as indicated by the arrow 81 to become the arc 73. From Fig. 6A, as shown in Fig. 6B, the arc generated between the contacts is continuous and moves and rotates on the fixed contact 13 and the movable contact 16 in a circular manner.

Next, a diagram of the dynamics of the arc 70 generated between the contacts is shown in FIG. In Fig. 7, Fig. 7(a) shows the dynamics of the arc, and Fig. 7(b) shows a cross-sectional view of the central portion of the arc. Fig. 7(a) shows the movement of the arc 70 occurring between the movable contact 16 and the fixed contact 13, and actually draws a circle continuously and moves. Further, the central portion of the arc 70 has an arc-shaped expanded shape.

Next, Fig. 7(b) shows a C-C cross-sectional view of the central portion of the arc 70. Fig. 7(b) shows the movement of the arc 70 in accordance with the left-hand rule of Fleming and the electromagnetic force to rotate clockwise. Further, when the direction of the current of the arc 70 is from the fixed joint 12 to the movable joint 17, the arc 70 rotates counterclockwise. Further, even if the N pole of the permanent magnet is opposite to the S pole, the arc 70 rotates counterclockwise. Of course Thereafter, the arc 70 moving at the contact is rapidly cooled by being driven while contacting the inner wall of the arc extinguishing device 18, and is arc-extinguished.

That is, in the first embodiment of the present invention, the arc generated at the contact is subjected to an electromagnetic force due to the magnetic field of the permanent magnet and its own current, and the direction thereof follows Fleming's left-hand rule. The direction of the magnetic field as seen from the contact is symmetrical about the centerline and varies from position to position. For this reason, since the direction of the electromagnetic force varies depending on the position, the arc that is moved by the electromagnetic force changes direction and moves, so that the circle moves in a clockwise rotation manner at the contact.

When the polarities of the permanent magnets are arranged in the opposite direction, since the direction of the electromagnetic force is opposite to 180°, the arc is driven to rotate in a counterclockwise direction in the opposite direction, and the same effect as the arrangement described above is obtained. The polarity is either one or the assembly property is excellent. Further, since the energization direction of the current is the same change, the same effect can be obtained in that direction, and the opening and closing performance without depending on the energization direction can be ensured. Further, in the present embodiment, in the case where the polarity of the permanent magnets is opposite to the direction in which the current is supplied, only the direction of the rotation of the arc is reversed, and the same effect can be obtained. Further, since the magnet is hidden under the fixed joint 12 and is not exposed to the arc, there is no need to protect the member for the permanent magnet, and it is excellent in terms of economy.

(Example 2)

Next, Embodiment 2 of the present invention will be described using the drawings. 8 is a perspective view showing the configuration of the periphery of the fixed joint 12 and the movable joint 17 in the case where the permanent magnet 15 is disposed on the side of the fixed joint 13. this 8 shows a diagram in which the fixed joint 12 is cut in the direction of the power supply and the load side, and the difference from FIG. 2B is the position of the permanent magnet. That is, the permanent magnet 15 is disposed in the load side direction of the fixed contact 13 of the protruding portion 121 of the fixed joint 12 where the fixed contact 13 is disposed.

Next, a plan view of the positions of the fixed contacts 13, the permanent magnets 15, and the projections 121 of the fixed joints shown in Fig. 8 is shown in Fig. 9(b) in a cross-sectional view taken along the center line. In Fig. 9(a), when the arc 70 between the contacts of the fixed contact 13 is considered to be such that the energization direction is from the movable contact to the fixed contact, the direction of the current is relative to the paper surface. Vertically flowing from the surface to the back, the direction of the magnetic field is such that the permanent magnet 15 is disposed on the right side of the fixed contact 13 to be in the direction of the arrow 100, and the electromagnetic force is applied to the oblique upper right direction by the left-hand rule of Fleming. .

Next, in the case of the foot 81 which is moved by the electromagnetic force from the foot 80 of the arc 70, the direction of the current flows from the surface to the back direction perpendicularly to the plane of the paper, and the direction of the magnetic field is inclined by the arrow 100 (dotted line arrow). In the lower left direction, the electromagnetic force acts as an arrow 100 on the oblique upper left direction. Therefore, the arc 70 moves from the foot 81 to the obliquely upper left direction and moves to the position of the foot 82. Next, when the arc 70 is at the foot 82, the direction of the current flows in the vertical direction of the foot 82 from the front to the back with respect to the paper surface, and the direction of the magnetic field is obliquely left upper direction as indicated by the arrow 102, so the electromagnetic force is as indicated by the arrow 92. The force that acts diagonally in the upper right direction. Thus, the arc 70 moves from the foot 82 to the foot 83.

Then, when the arc 70 is at the foot 83, the direction of the current is at the foot. Since the direction of the magnetic field is obliquely in the upper right direction as indicated by the arrow 103 with respect to the paper surface from the front to the back, the electromagnetic force acts as a force in the upper right direction as indicated by the arrow 93, and remains at this position. That is, when seen from the load side, the area of the arc 70 on the left half of the fixed contact 13 moves in a circular shape, and the area on the right half of the fixed contact 13 stays in a state of staying. Then, when seen from the load side, the arc 70 generated on the left half is drawn clockwise and moves to the right half. At this time, since it is driven while being in contact with the inner wall of the arc extinguishing device 18, it is rapidly cooled and is arc-extinguished.

Further, regarding the arc generated on the right half as seen from the load side, the arc is cooled and extinguished at an early stage due to early contact with the inner wall side of the arc extinguishing device 17.

Next, a cross-sectional view of the center line of Fig. 9(a) is shown in Fig. 9(b). In Fig. 9(b), the permanent magnet 15 is placed on the projection portion 121 of the fixed joint 12 on the load side of the fixed contact 13, so that the fixed joint of the permanent magnet 15 is N pole, and the load side is S pole. With such a configuration of the permanent magnet 15, the magnetic lines of force are radially discharged from the N-pole throughout the entire circumference and return to the S-pole by a parabola. Therefore, the fixed contact 13 is oriented in the direction of the magnetic field shown in Fig. 9(a). Further, in the second embodiment, the permanent magnet 15 is disposed on the load side of the fixed contact 13, but the effect is also the same when disposed on the power supply side.

11‧‧‧Power side terminal

12‧‧‧Fixed joints

13‧‧‧Fixed joints

14‧‧‧ Arc Emissions

15‧‧‧ permanent magnet

16‧‧‧ movable joints

17‧‧‧ movable joint

18‧‧‧Arc extinguishing device

27‧‧‧Rotating fulcrum of movable joint

111‧‧‧Power cable connection hole

121‧‧‧Slim extension of the fixed joint

Claims (5)

A circuit breaker for interrupting an overcurrent or a short-circuit current flowing through a circuit, characterized by comprising: a fixed joint connected to the circuit and having a fixed contact, and configured to face the fixed contact a movable joint that contacts or opens the movable joint, and an arc extinguishing device that extinguishes an arc generated between the fixed joint and the movable joint, wherein the fixed joint forms a folded elongated protrusion, and The fixed contact is disposed on the elongated protrusion of the fixed joint, and an arc-increasing device is disposed on the back side of the elongated protrusion, and a permanent magnet is disposed in the arc-incident device. The circuit breaker of claim 1, wherein the fixed joint is formed by bending the power terminal into an inverted L shape, and then bending into an L shape, and punching a central portion of the bent horizontal plate. The shape of the plaque is further reduced, and the horizontal plate is further bent into a stepped state in a state in which the elongated protrusion of the center is left. The circuit breaker of claim 1, wherein the arc-increasing device has a concave shape at a center, and the permanent magnet is disposed in the concave shape, and a spacer is formed on both sides of the permanent magnet. The circuit breaker of claim 1, wherein the arc generated by the movable contact and the fixed contact is rotated, and the arc extinguishing device is used for arc extinguishing. A circuit breaker, which is a circuit breaker for interrupting an overcurrent or a short-circuit current flowing in a circuit, characterized by: having: connecting to the foregoing circuit and having a fixed joint having a fixed contact, a movable joint having a movable contact disposed opposite to the fixed contact and contacting or being separated, and an arc for arc generated between the fixed contact and the movable contact The arc extinguishing device is formed by bending the power terminal into an inverted L shape, and then bending into an L shape, punching a central portion of the bent horizontal plate into a U shape, and further staying a state in which the horizontal plate is bent in a stepped state in a state in which the upper center has an elongated projection, and the fixed contact is disposed on the elongated protrusion of the fixed joint, and is disposed at the fixed contact of the protrusion. A permanent magnet is provided on the load side or the power supply side.