JP2002008508A - Circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit breaker that can generate sufficient circuit opening speed and a force to extend an arc to the arc extinguishing plate, even when a fixed contact structure is used that enables to make shorter the height of the circuit breaker as much as possible. SOLUTION: The fixed contact 5 comprises a parallel conductor portion 7a which has a fixed contact 6 at one end and in which flows a nearly parallel and reverse direction current with a movable contact 1 that is in a closed state and a reverse parallel conductor 7b which is connected with the above parallel conductor at one end and arranged at both right and left sides of the parallel conductor and in which flows a nearly parallel and the same direction current with the movable contact point that is in a closed state. A pair of magnetic plate 10 are arranged on the side of the movable contact point of the reverse parallel conductor in a state to be clamped from both sides at one end of the movable contact point 2 side of the above movable contact. The distance between each magnetic plate and the arc extinguishing plate of the magnetic unit provided at one end of the above movable contact opposed to it is respectively made smaller than the distance between each magnetic plate composing the pair of the magnetic plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker for separating contacts using electromagnetic force generated between parallel conductors by a short-circuit current.

[0002]

2. Description of the Related Art FIG. 14 is a partial sectional view showing a conventional circuit breaker disclosed, for example, in Japanese Patent Publication No. 62-2423, wherein reference numeral 1 denotes a movable contact having a movable contact 2 fixed to one end. Reference numeral 5 denotes a fixed contact having a fixed contact 6 which forms a contact pair with the movable contact 2, and is connected to a power supply circuit at a terminal 15a. In the closed state, the movable contact 1 and the fixed contact 5 are vertically overlapped at a slight interval and are held parallel to each other. 13 is a plurality of arc extinguishing plates held by the arc extinguishing side plate 14, 25 is a mechanism for opening and closing the movable contact 1, and 29 is a handle for manually operating the mechanism 25. These components are the cover 28 and the base 2
7 are housed.

Next, the operation will be described. In opening and closing at the time of normal energization, the mechanism unit 25 operates by operating the handle 29, and the movable contact 1 rotates to open and close. On the other hand, when a large current such as a short-circuit current flows in the closed state, the contacts are separated by the electromagnetic repulsive force due to the reverse current flowing through the movable contact and the fixed contact, regardless of the above-described mechanism, and subsequently the overcurrent is generated. In response, the operation of the tripping mechanism (not shown) drives the mechanism section 25 to the cutoff state. Therefore, an arc can be generated between the contacts 2 and 6 at an early stage immediately after the occurrence of the accident, and this arc can be rapidly extended, and the arc voltage between the contacts rises quickly. This arc voltage limits the fault current. Subsequently, when the instantaneous current value decreases, the arc is drawn into the arc-extinguishing plate 13 made of iron, divided, cooled, and extinguished, so that the current is interrupted.

[0004] In the circuit breaker shown in FIG. 14, the fixed contact 5 is provided with the movable contact 1 in a closed state.
In order to secure a parallel conductor portion 7a which is opposed to and parallel to which a current flows, a fixed contact 6 is fixed to a distal end portion facing the movable contact. In such a fixed contact, in order to reduce the influence of the current flowing through the anti-parallel conductor 7b that generates an electromagnetic attraction to the movable contact 1, the vertical conductor 7e is restricted due to the restriction of the mold during bending. However, it is difficult to reduce the height of the circuit breaker in the height direction, and furthermore, the conductor of the fixed contact becomes longer and the parts cost increases.

[0005] Therefore, in another conventional circuit breaker disclosed in the above-mentioned publication, the height of the circuit breaker is reduced by the fixed contact structure shown in FIG. In FIG. 15, the fixed contact 5 has a U-shaped hole 36 at a portion facing the movable contact 1 (not shown) so as to form a tongue extending from the distal end 5b toward the proximal end 5a. Is provided. The tongue is formed by a parallel conductor 7a parallel to the closed movable contact and through which a current flows in the opposite direction, and a fixed contact 6 fixed to one end of the parallel conductive portion 7a. Anti-parallel conductor 7 through which current flows in the same direction
b is arranged at the same height as the parallel conductor portion 7a, and FIG.
There is no conductor extending in the vertical direction as in the vertical conductor portion 7e. Therefore, the dimension of the circuit breaker in the height direction can be reduced, and the convenience of the user is improved. Further, it is not necessary to use a bending process for manufacturing the fixed contact, and the workability is improved.

[0006]

In the conventional circuit breaker, a parallel conductor portion which generates an electromagnetic repulsion by flowing a current in the opposite direction parallel to the movable contact in a closed state and other fixed contacts are formed. By arranging the electric circuit and the electric circuit at the same height, the height dimension could be reduced.However, a current flowing in the same direction and in the same direction as the closed movable contact caused electromagnetic attraction to the movable contact. The existence of the antiparallel conductor to be generated makes it impossible to sufficiently increase the opening speed of the movable contact at the time of a short circuit accident. In particular, when the width of the circuit breaker is limited in the width direction (the direction perpendicular to the direction in which the movable contact extends), the antiparallel conductor portion is arranged at the same height as the parallel conductor portion. The force for electromagnetically attracting the movable contact generated by the current flowing through the movable contact may be larger than when the substantially U-shaped fixed contact shown in FIG. 14 is used, and the opening speed of the movable contact decreases. Therefore, there is a problem that sufficient current limiting performance cannot be obtained.

Further, the magnetic field component generated by the current flowing through the antiparallel conductor cancels the magnetic field component extending the arc generated by the current flowing through the parallel conductor to the arc-extinguishing plate. It is difficult to separate and cool the plate. As a result, there has been a problem that the shut-off time becomes longer and wear of the arc-extinguishing chamber components increases, and in the worst case, the shut-off becomes impossible.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems. Even in a circuit breaker having a reduced size in the height direction, the circuit breaker has excellent current limiting performance. The purpose is to obtain.

[0009]

In the circuit breaker according to the present invention, the fixed contact has a fixed contact at one end, and is substantially parallel to the movable contact in the closed state and in which a reverse current flows. A conductor portion, and an anti-parallel conductor portion connected to the parallel conductor at one end and arranged on both left and right sides of the parallel conductor portion and substantially parallel to the movable contact in a closed state and in which current flows in the same direction. In this way, a pair of magnetic plates are arranged on the movable contact side of the anti-parallel conductor portion so as to sandwich one end of the movable contact on the movable contact side from the left and right, thereby forming the pair of magnetic plates. The distance between each magnetic plate and the magnetic extinguishing plate provided opposite to one end of the movable contact is made smaller than the distance between the magnetic plates.

An arc runner extends from one end of the parallel conductor, and when the direction in which the movable contact is separated from the fixed contact is upward, the fixed contact moves upward from the other end of the anti-parallel conductor. A connecting conductor vertical portion that extends in the direction and is connected to the terminal portion, and the connecting conductor vertical portion is provided with a slit at a portion that intersects a surface including a trajectory at the time of the opening and closing operation of the movable contact. A pair of magnetic plates are respectively opposed to a pair of conductors that form left and right connection conductor vertical portions of the slit.

An arc runner extends from one end of the parallel conductor, and when the direction in which the movable contact is separated from the fixed contact is upward, the fixed contact moves upward from the other end of the anti-parallel conductor. The connecting conductor has a connecting conductor vertical portion extending in the direction and connected to the terminal portion, and a magnetic shielding plate is disposed on the front surface of the connecting conductor at the fixed contact side.

The connecting conductor vertical portion is provided with a slit at a portion that intersects a plane including a locus of the movable contact at the time of opening / closing operation, and a pair of conductors forming left and right connecting conductor vertical portions of the slit. A pair of shielding plates made of a magnetic material are arranged on the front surface of the fixed contact side of the unit.

An arc runner extends from one end of the parallel conductor. The tip of the arc runner is outside the space surrounded by the pair of magnetic plates, and the direction in which the movable contact is separated from the fixed contact is determined. When it is set to the upper side, a magnetic arc extinguishing plate is arranged in an upper space at the tip of the arc runner.

The fixed contact has a connecting conductor vertical portion extending upward from the other end of the anti-parallel conductor portion and connected to the terminal portion, and includes one of a plurality of magnetic material arc extinguishing plates. The arc extinguishing plate of the portion is disposed between the vertical portion of the connecting conductor and the pair of magnetic plates.

An arc runner is provided at one end of the parallel conductor, and a projection is provided at a portion extending from the side of the fixed contact of the insulating cover to the other end of the parallel conductor. Is formed in a trumpet shape extending toward the arc runner.

An arc runner extends from one end of the parallel conductor portion, and a portion from just beside the fixed contact of the insulating cover to the other end portion of the parallel conductor portion is heated by the arc heat from the other portion. It is formed of a substance that generates a large amount of vapor.

An arc runner extends from one end of the parallel conductor. The arc runner, the movable contact, the fixed contact, the pair of magnetic plates and the magnetic extinguishing plate are housed in a housing. Between the inner surface of the housing and the surface of the pair of magnetic plates on the side opposite to the movable contact, a flow path communicating from a space near the tip of the arc runner is formed.

Also, of the magnetic pieces that have a plurality of poles and form a pair of magnetic plates for each pole, the magnetic piece on the pole side is integrated with the adjacent magnetic piece of the other pole. Things.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a view for explaining a circuit breaker according to Embodiment 1 of the present invention, and more specifically, is a partial cross-sectional perspective view of an arc extinguishing unit in an open state. FIG. 2 is an exploded view of main parts arranged in the arc extinguishing unit. FIG. 3 is a development view showing a configuration of a circuit breaker configured using the arc extinguishing unit shown in FIG.

In FIG. 1, reference numeral 1 denotes a movable contact 2 at one end.
Movable contacts 5 (not shown) are fixed contacts that form a pair of contacts with the movable contact 1. Reference numeral 10 denotes a pair of substantially L-shaped magnetic plates, which are disposed so as to sandwich the movable contact 1 from the left and right.
The side surface is covered with an insulating cover 12. Reference numeral 13 denotes a plurality of horseshoe-shaped arc-extinguishing plates made of a magnetic material held on the arc-extinguishing side plate 14. Reference numeral 17 denotes a spring for generating a contact pressure on the movable contact 1, one end of which is held by a spring hook 18. Reference numeral 16 denotes a sliding contact for electrically connecting the terminal 15c to the movable contact 1, and 19 denotes a movement of a mechanism 25 (not shown) to the movable contact 1 via a crossbar 24 (not shown). It is a rotor for transmission, and its section is taken so that the internal structure of the rotor can be understood. The components forming these arc extinguishing units are housed in the arc extinguishing unit housing main body 21 and the arc extinguishing unit housing lid 22.

Referring to FIG. 2, the main components inside the arc extinguishing unit will be described in more detail.
Has a tongue piece to which the fixed contact 6 is fixed. The tongue piece is parallel to the movable contact 1 in the closed state, and a parallel conductor portion 7 a through which a current flows in the opposite direction.
It has an arc runner 9 extending to the side. The parallel conductor 7a is connected to one end of the anti-parallel conductor 7b on the rotor 19 side, and the anti-parallel conductor 7b is disposed at substantially the same height on the left and right of the parallel conductor 7a. The other end is connected to the terminal 15a via a connection conductor vertical portion 7c extending in the up-down direction and a connection conductor parallel portion 7d extending in the front-rear direction. The connection conductor vertical portion 7c and the connection conductor parallel portion 7d are provided with slits 8 along a plane including a locus of rotation of the movable contact 1. Anti-parallel conductor part 7 of fixed contact 5
Above b, a pair of magnetic plates 10 electrically insulated from the fixed contact by an insulating sheet 11 are arranged so as to sandwich the movable contact 2 side end of the movable contact 1, and between the contacts. The inner surfaces, the rotor-side end surfaces, and the arc-extinguishing plate 13-side end surfaces of the pair of magnetic plates 10 exposed to the generated arc are covered with an insulating cover 12.

The pair of magnetic plates extend along a portion 10a of the first magnetic plate extending in the vertical direction on the left and right sides of the movable contact 1 and an antiparallel conductor portion 7b, and one end surface is connected to the connection conductor vertical portion 7c. At the portion 10b of the second magnetic plate facing the
Each is substantially L-shaped. The insulating cover 12 is a portion 12a of the first insulating cover that covers the pair of magnetic plates.
And a portion 12b of the second insulating cover that covers the upper surface of the parallel conductor portion 7a and a portion 12c of the third insulating cover that covers the connecting conductors 7c and 7d. A plurality of magnetic substance extinguishing plates 13 held by the extinguishing side plate 14 are arranged on the insulating cover. The shape of the arc extinguishing plate is a horseshoe shape having a notch on the movable contact 1 side. In addition, the movable contact 1 is rotatably held by the movable member rotating shaft 4, and has a configuration in which the movement of the mechanism section 25 (not shown) is transmitted via the rotor 19. This rotor 19 has
A through hole for communication with the crossbar 24 (not shown) is provided. As shown in FIG. 3, a plurality of such arc extinguishing chamber units 23 are connected to the rotor by a plurality of crossbars 24, the crossbars are engaged with the mechanical unit 25, and abnormalities in the circuits and the crossbars are detected. A circuit breaker is configured by housing the relay unit 26 for driving the mechanism unit and the handle 29 in a housing including the cover 28 and the base 27.

Next, the operation will be described. In opening and closing at the time of normal energization, the mechanism unit 25 operates by operating the handle 29, and the movable contact 1 rotates to open and close. On the other hand, when a large current such as a short-circuit current flows in the closed state, the contacts are separated by the electromagnetic repulsive force due to the reverse current flowing through the movable contact and the fixed contact, regardless of the above-described mechanism, and subsequently the overcurrent is generated. In response, the operation of the relay unit 26 drives the mechanism unit 25 to the cutoff state. Therefore, immediately after the accident,
An arc can be generated between the contacts 2, 6 and this arc can be rapidly extended and the arc voltage between the contacts rises quickly. This arc voltage limits the fault current. Subsequently, when the instantaneous current value decreases, the arc is drawn into the arc-extinguishing plate 13 made of iron, divided, cooled, and extinguished, so that the current is interrupted. These breaking operations are basically the same as those of the above-described conventional circuit breaker. A parallel conductor 7 parallel to the movable contact in the closed state and in which a current in the opposite direction flows.
a, and the antiparallel conductor portion 7b, which is parallel to the movable contact in the closed state and through which current flows in the same direction, is arranged at the same height as the electric circuit 7a, so that the size of the circuit breaker in the height direction can be reduced. Similar to the above-described another conventional circuit breaker, the convenience of the user is improved, and the necessity of using a bending process in the production of the fixed contact element is eliminated to improve the workability.

However, in this embodiment, unlike the other conventional circuit breaker described above, a pair of substantially L-shaped magnetic plates 10 are arranged above the anti-parallel conductor portion 7b. A magnetic circuit is formed by the plate and the magnetic substance extinguishing plate 13,
This prevents the magnetic field component generated by the current of the antiparallel conductor 7b from acting on the arc generated between the movable contact 1 and the contacts, and promotes the driving of the movable contact and the arc.

FIGS. 4 and 5 are explanatory diagrams schematically showing the positional relationship between the movable contact 1, the fixed contact 5, the pair of magnetic plates 10 and the arc-extinguishing plate 13 in the present embodiment. FIG.
FIG. 5 shows a closed state, and FIG. 5 shows a state in which the movable contact is in the maximum open state during the breaking operation. FIG.
It is the figure which looked at (b) from the upper part. 4 and 5
In (b), the current flows are indicated by outline arrows. As shown in FIG. 5A, the interval W between the pair of magnetic plates 10 provided above the antiparallel conductor portion 7b is larger than the gap d1 between the pair of magnetic plates 10 and the arc-extinguishing plate 13. Have been.

With this configuration, in the closed state shown in FIG. 4, the magnetic flux generated by the current flowing through the antiparallel conductor portion 7b (a magnetic field component that prevents the movable contact 1 from opening) is
Since it passes through a magnetic circuit formed by the pair of magnetic plates 10 and the arc-extinguishing plate 13, it does not act on the movable contact 1 (the movable contact 1 is shielded from a magnetic field component generated by a current flowing through the antiparallel conductor 7b). ). Furthermore, the movable contact 1 in the closed state
Is located in a space surrounded by a substantially U-shaped magnetic body formed by the pair of magnetic body plates 10 and the arc extinguishing plate 13,
Attraction force by the magnetic material acts, and the opening speed is improved (in other words, current limiting performance is improved).

Similarly, as shown in FIG. 5 (b), the magnetic field generated by the current flowing through the anti-parallel conductor portion 7b does not act on the arc generated between the contacts, and the arc causes the current of the parallel conductor portion 7a to change. Are pushed out to the arc runner 9 by the magnetic field generated by the. Further, the arc is located in a space surrounded by a substantially U-shaped magnetic body formed by the pair of magnetic body plates 10 and the arc extinguishing plate 13, and is simulated by a horseshoe-shaped arc extinguishing plate. (Notch left and right portions of the arc extinguishing plate) extend to the movable contact 1 side, so that the arc extinguishing plate 1 acting on the arc
The suction force to 3 is improved. The improvement of the attraction force makes the point at which the arc is divided and cooled by the arc-extinguishing plate earlier, so that the cut-off time can be shortened and the wear of the arc-extinguishing chamber can be reduced. In addition, it is possible to prevent the hot gas from being filled with the arc time and being unable to be cut off.

By the way, the terminal portion of the circuit breaker is generally provided at a position higher than the mounting surface due to the connection screws for the electric wires. On the other hand, the fixed contact 6 is provided on the bottom surface side (the mounting surface side) as much as possible in order to reduce the height direction of the circuit breaker by maximizing the space inside the housing.
Therefore, as shown in FIG. 5B, a conductor connecting the terminal portion 15a and the fixed contact 6 must have a connecting conductor vertical portion 7c extending in the vertical direction. Since the current flowing through the connecting conductor vertical portion 7c is substantially parallel and in the opposite direction to the current flowing through the arc, the arc pushed out by the arc runner 9 and driven toward the arc extinguishing plate 13 is moved toward the fixed contact 6 side. Generates an electromagnetic force that pushes back. In order to reduce the electromagnetic force that pushes back the arc, a slit 8 is provided in the connection conductor vertical portion 7c, and the connection conductor vertical portion 7c is disposed at a position shifted left and right from the running direction of the arc. Furthermore, the end face on the terminal portion 15a side of the portion 10b of the second magnetic plate of the pair of substantially L-shaped magnetic plates 10 is opposed to the connection conductor vertical portion 7c arranged at the position shifted to the left and right. Are located in
The magnetic field generated by the current in the connecting conductor vertical portion 7c is, like the antiparallel conductor portion 7b, a pair of the magnetic plate 10 and the arc-extinguishing plate 1.
The arc driven by the arc-extinguishing plate is pushed back to the contact side again by the electromagnetic force in the reverse driving direction because it is hard to act on the arc because it is shielded by the magnetic circuit composed of Thus, a circuit breaker that is less likely to fail due to restriking due to restriking can be obtained.

In this embodiment, since the core is constituted by a pair of substantially L-shaped magnetic plates 10, a general U-shaped magnetic plate in which left and right magnetic plates are connected at the upper portion. Superior in workability and assemblability compared to core.

Embodiment 2 FIG. FIG. 6 is a diagram for explaining a main part of a circuit breaker according to Embodiment 2 of the present invention. In FIG. 6, components denoted by the same reference numerals as those in FIGS. 1 and 2 are the same or corresponding components.

In FIG. 6, 1 is a movable contact having a movable contact 2, 5 is a fixed contact having a fixed contact 6, 15a
Is a terminal portion, 10 is a pair of rectangular magnetic plates long in the front-rear direction, and 13 is a plurality of magnetic arc extinguishing plates provided on the top of the ten pairs of magnetic plates. FIG. 1A shows the same as FIG.
5 is a left side view of the arc extinguishing plate, excluding arc extinguishing plates other than the lowermost arc extinguishing plate 13a. The distance d2 between the lowermost arc extinguishing plate 13a and the pair of magnetic plates 10 is arranged to be smaller than the distance W between the magnetic plates of the pair of magnetic plates 10. Although FIG. 2 shows only the main part of the present embodiment, other components constituting the circuit breaker are basically the same as those of the first embodiment.

In the present embodiment, a pair of magnetic plates 10 are provided along the antiparallel conductor portion 7b, and a magnetic circuit is formed by the pair of magnetic plates and the arc-extinguishing plate. Is shielded from the magnetic field component generated by the current flowing through the antiparallel conductor portion 7b, the attractive force of the magnetic material acts on the movable contact 1 in the closed state to improve the opening speed, and the current flowing through the connection conductor vertical portion 7c is reduced. As in the first embodiment, the magnetic circuit component for pushing back the arc to be produced between the contacts is shielded by the magnetic circuit. However, in the present embodiment, the magnetic circuit
Since the lower arc extinguishing plate 13a is mainly formed by the pair of magnetic plates 10 and the lowermost arc extinguishing plate 13a, it is necessary to increase the thickness so that the lowermost arc extinguishing plate 13a is not magnetically saturated.

In this embodiment, since the space surrounded by the pair of magnetic plates 10 is limited to the fixed contact side, a large-capacity arc-extinguishing plate is arranged in the upper space of the pair of magnetic plates. As a result, the heat capacity of the arc extinguishing plate is increased, and wear of the arc extinguishing plate due to the heat of the arc at the time of short-circuit interruption can be reduced.

Further, compared with the pair of substantially L-shaped magnetic plates shown in the first embodiment, the distance between the pair of magnetic plates 10 and the distal end of the movable contact in the open state can be increased. Insulation of plate 10 is insufficient, movable contact 1, magnetic plate 1
0, It is possible to prevent a current from flowing in the path of the fixed contact 5 and making it impossible to cut off. Further, since the shape of the magnetic plate is simplified, the utilization rate of the plate material for cutting out the pair of magnetic plates is improved.

Embodiment 3 FIG. FIG. 7 is a diagram for describing a main part of a circuit breaker according to Embodiment 3 of the present invention. In FIG. 7, components denoted by the same reference numerals as those in FIGS. 1 and 2 are the same or corresponding components.

In FIG. 7, 1 is a movable contact having a movable contact 2, 5 is a fixed contact having a fixed contact 6, 15a
Is a terminal portion, 10 is a pair of rectangular magnetic plates long in the vertical direction, and 13 is a plurality of magnetic arc extinguishing plates provided above the pair of magnetic plates. FIG. 2A is a top view of FIG. 1B, and the distance W3 between the pair of magnetic plates 10 is larger than the distance d3 between the arc-extinguishing plate 13 and the pair of magnetic plates 10. Are located in Although FIG. 2 shows only the main part of the present embodiment, other components constituting the circuit breaker are basically the same as those of the first embodiment.

In the present embodiment, a pair of magnetic plates 10 are provided above the antiparallel conductor 7b, and a magnetic circuit is formed by the pair of magnetic plates and the arc-extinguishing plate. The shielding from the magnetic field component generated by the current flowing through the antiparallel conductor portion 7b, the attraction force by the magnetic material acting on the movable contactor 1 in the closed state to improve the opening speed, and the pseudo pair of magnetic material plates 10, The foot portion of the horseshoe-shaped extinguishing plate (the left and right portions of the notched portion of the extinguishing plate) is equivalent to a configuration extending to the movable contact 1 side, and the attraction force to the arc extinguishing plate 13 acting on the arc is improved. Is the same as in the first embodiment. However, in the present embodiment, since the pair of magnetic plates 10 are not disposed at positions facing the connection conductor vertical portion 7c, a magnetic field component that pushes back an arc generated by a current flowing through the connection conductor vertical portion 7c between the contacts is generated by the pair of magnetic plates. There is no shielding by the magnetic plate 10. Instead, this magnetic field component is generated by a pair of magnetic plates 10 and connecting conductor vertical portions 7.
c of the plurality of magnetic arc extinguishing plates 13 arranged between
At b, it is shielded against the arc.

In the present embodiment, the space surrounded by the pair of magnetic plates 10 is limited to the contact pair side, so that the number of arc extinguishing plates provided above the arc runner 9 can be increased. Arc breaking and cooling action by the arc extinguishing plate are improved. As a result, the cutoff performance and the DC cutoff performance in a current region below an overload, which greatly affects the cutoff performance, are improved, and the improvement of the arc cooling function suppresses an increase in the internal pressure of the housing at the time of short circuit cutoff. Can be Further, since the shape of the magnetic plate is simplified, the utilization rate of the plate material for cutting out the pair of magnetic plates is improved.

Embodiment 4 FIG. 8 is a diagram for describing a main part of a circuit breaker according to Embodiment 4 of the present invention. In FIG. 8, components denoted by the same reference numerals as those in FIGS. 1 and 2 are the same or corresponding components.

In FIG. 8, 5 is a fixed contact having a fixed contact 6, 15a is a terminal portion, and 10 is a pair of substantially L-shaped magnetic plates (in FIG. 8, the near side magnetic plate is omitted). , 3
Reference numeral 0 denotes a magnetic shielding plate provided on the arc runner 9 side of the connection conductor 7c. Although FIG. 2 shows only the main part of the present embodiment, other components constituting the circuit breaker are basically the same as those of the first embodiment.

In the present embodiment, unlike the first embodiment, a magnetic field component that pushes an arc generated by the current of the connecting conductor vertical portion 7c back to the contact pair side is shielded. The shielding plate 30 is provided, thereby further improving the shielding effect.

However, if the shielding plate 30 is provided between the tip of the arc runner 9 and the connecting conductor vertical portion 7c as described above, the space in which the arc column extends becomes small, and the sharp arc immediately before interruption due to the extension of the arc becomes small. No voltage rise occurs. When the number of arc extinguishing plates cannot be sufficiently provided due to limitations on the dimensions of the housing and the like, if the arc voltage is not increased due to the arc extension, the breaking performance is significantly reduced. In particular, the tendency is large in DC cutoff in which a current zero does not naturally occur.

Embodiment 5 FIG. FIG. 9 is a diagram for explaining a main part of a circuit breaker according to Embodiment 5 of the present invention. In FIG. 9, components denoted by the same reference numerals as those in FIGS. 1 and 2 are the same or equivalent.

In FIG. 9, 5 is a fixed contact having a fixed contact 6, 15a is a terminal portion, 10 is a pair of substantially L-shaped magnetic plates (in FIG. 9, the near side magnetic plate is omitted). , 3
Reference numeral 1 denotes a pair of magnetic shielding plates provided on the arc runner 9 side of the connection conductor 7c. Although FIG. 2 shows only the main part of the present embodiment, other components constituting the circuit breaker are basically the same as those of the first embodiment.

In the present embodiment, a part corresponding to the shield plate 30 shown in the fourth embodiment is a pair of substantially L-shaped shield plates 31, and the shield plate 31 uses the parts of the connection conductor vertical portion 7 c. By covering the surface on the fixed contact 6 side and the surface on the slit 8 side, the magnetic field component that pushes back the arc generated by the current of the connection conductor vertical portion 7c between the contacts is shielded from the arc.
Further, since the shielding plate 31 does not block the slit 8 provided in the connection conductor vertical portion 7c, a space where the arc extends can be secured, and the above-described deterioration of the blocking performance does not occur.

Embodiment 6 FIG. FIG. 10 is a top view for describing main parts of a circuit breaker according to Embodiment 6 of the present invention. In FIG. 10, components denoted by the same reference numerals as those in FIGS. 1 and 2 are the same or corresponding components.

In FIG. 10, 5 is a fixed contact having a fixed contact 6, 9 is an arc runner extending from the fixed contact to the terminal 15a side, and 10 is a substantially L-shaped surface covered with an insulating cover 12 on the contact pair side. A pair of character-shaped magnetic plates 13 are arc extinguishing plates. Although only the main parts of the present embodiment are shown in the figure, the other parts constituting the circuit breaker are as follows:
Basically, it is the same as the first embodiment.

In the present embodiment, a projection 12d is provided at a position on the movable contact rotation center 4 (not shown) side from right and left of the fixed contact 6 of the insulating cover 12 to reduce the space surrounded by the projection. It has a trumpet shape opened on the arcana 9 side. As a result, in addition to the magnetic driving force of the current flowing through the parallel conductor portion 7a and the attraction force of the magnetic material, the arc generated between the contact points, as shown by the white arrow in FIG. The force of the pressure reflection of the arc at the surface and the force of the steam flow from the trumpet-shaped wall due to the arc heat,
Since the arc acts to push the arc toward the arc runner 9, the arc leaves the fixed contact 6 and moves to the tip of the arc runner 9 in a shorter time. Thereby, the fixed contact 6
As a result, the time at which the arc touches the arc-extinguishing plate 13 is shortened, and the interruption time is reduced, so that the arc-extinguishing unit is reduced in wear, and a highly reliable circuit breaker capable of repeatedly performing an interruption operation is provided. can get.

By the way, when the projection 12d is provided,
The inner width W ′ (width of the space in which the movable contact moves) of the insulating cover 12 closer to the movable contact rotation center 4 (not shown) than the fixed contact 6 is reduced, and the movable contact 1 (not shown) is reduced. The movable contact and the inner wall of the insulating cover come into contact with each other due to
The current limiting performance may be degraded due to the decrease in the opening speed, or the interruption may be caused by insulation breakdown through the surface of the insulating cover 12 during the interruption operation. Therefore, in the case where the left and right movement of the movable contact is large, the trumpet-shaped portion 12d cannot be provided.

Embodiment 7 FIG. In the present embodiment, even when it is difficult to provide a projection on the insulating cover as in the above-described sixth embodiment, a force for pushing the arc can be generated by the vapor from the wall surface due to the arc heat.

FIG. 11 is a top view illustrating a main part of a circuit breaker according to a seventh embodiment of the present invention.
In FIG. 11, the same reference numerals as in FIG.
The same or equivalent. Although FIG. 2 shows only the main part of the present embodiment, other components constituting the circuit breaker are basically the same as those of the first embodiment.

In this embodiment, the protrusion 12d shown in FIG.
Instead of this, a part 12e of the insulating cover is made of a material that generates a large amount of steam by the heat of the arc from the other parts of the insulating cover.
A large amount of vapor generated from the pressure causes a pressure difference before and after the arc generated between the contacts, so that the arc is generated by the arc runner 9.
Driven to the side. Accordingly, the driving force of the arc by the insulating cover vapor due to the heat of the arc is obtained together with the driving force of the arc by the electromagnetic force, and the movable contact 1 (not shown) is provided by the insulating cover wall. It is possible to prevent the current limiting performance from deteriorating due to touching and failure to shut off.

In general, the insulating cover 12 is often made of a resin material having good moldability. However, the insulating cover is subjected to arc pressure and high heat when current is interrupted, so that the mechanical strength and heat resistance are increased. Fill the reinforcing material with glass fiber and ceramic particles. When such a reinforced resin material is used as a main component of the insulating cover, by using a non-reinforced resin or a resin in which the reinforcing material is reduced for the part 12e of the insulating cover, the part 12e of the insulating cover is relatively formed.
e can generate more steam than other parts.

Embodiment 8 FIG. FIG. 12 is a partial sectional view for illustrating a main part of a circuit breaker according to an eighth embodiment of the present invention. In FIG. 12, components denoted by the same reference numerals as those in FIGS. 1 and 2 are the same or corresponding components.

In FIG. 12, reference numeral 32 denotes a connecting conductor vertical portion 7.
c (not shown); 33, an insulator covering the outer surfaces of the pair of substantially L-shaped magnetic plates 10; 34, a pair of the magnetic plates 10 and the arc-extinguishing unit casing from the tip of the arc runner 9; The flow path is formed by a gap between the body 21 and the arc-extinguishing unit housing lid 22. The insulator 33 and the insulating cover 12 are integrally formed, and the pair of magnetic plates 10 are entirely covered with the insulator except for the end faces facing the fixed contact 5. 2A is a cross section taken along line C1-C1 in FIG. 2B, FIG. 2B is a cross section taken along line C2-C2 in FIG. 2A, and FIG. And the rotor 19 are omitted. Although FIG. 2 shows only the main part of the present embodiment, other components constituting the circuit breaker are basically the same as those of the first embodiment.

As described above, the arc generated between the contacts is driven to the tip of the arc runner 9 and cut by the arc extinguishing plate 13.
Cooled. The arc that reaches the arcana tip
In addition to the reverse driving force (the driving force that pushes the arc back from the tip of the arc runner 9 to the fixed contact 6) due to the current flowing through the connection conductor vertical portion 7c, the arc is driven to the tip of the arc runner. The arc covering the portion covering the portion 7c comes close to the arc, and another reverse driving force is generated by the vapor pressure generated from the insulator due to the heat of the arc. In order to reduce this other reverse driving force, in this embodiment,
As an insulator covering the connection conductor vertical portion 7c, a ceramic 32 which is relatively unlikely to generate steam due to the heat of the arc is used.

Further, as the arc travels from the fixed contact 6 to the tip of the arc runner 9, the gas on the front of the arc is pushed to increase the pressure on the front of the arc to reduce the arc traveling speed, or the arc reaching the tip of the arc runner 9. The metal vapor generated from the gas may return between the contacts and re-ignite between the contacts. These not only increase the wear time of the arc-extinguishing unit by lengthening the cutoff time, but also may cause a cutoff failure. Therefore, in the present embodiment, in order to prevent a pressure rise on the front of the traveling arc and a backflow of the metal vapor between the contacts,
A flow path 34 extending from the tip of the arcrunner to the back side of the pair of magnetic plates 10 is provided to generate an airflow indicated by a white arrow in FIG.

Embodiment 9 FIG. FIG. 13 is a partial cross-sectional view of a multi-pole circuit breaker for illustrating a main part of a circuit breaker according to Embodiment 9 of the present invention. In FIG.
1 and 2 are the same or equivalent.

In FIG. 13, reference numeral 12f denotes an end electrode insulating cover for insulating the magnetic pieces 10a or 10f arranged at the left and right ends of the circuit breaker, and 12g denotes the magnetic pieces 10b, 10c or 10g disposed between the poles. An inter-electrode insulating cover 35 that insulates the pair of 10d and 10e interlocks the movement of the movable contact 1 between the respective poles, and also moves the movable contact 1 via the movable contact rotating shaft 4 (not shown). It is a crossbar that holds. Further, an arc extinguishing unit housing for accommodating the arc extinguishing device is not provided, and the arc extinguishing device and the like are directly accommodated by the base 27 (not shown) and the cover 28. Further, although the magnetic material arc extinguishing plate 13 is omitted, a pair of magnetic material plates is provided along each anti-parallel conductor portion 7b (not shown) at each pole, and the pair of magnetic material extinguishing plates and the arc extinguishing plate are provided. A magnetic circuit is formed by the plate and the movable contact 1 is shielded from a magnetic field component generated by a current flowing through the antiparallel conductor portion 7b. As in the first embodiment, the speed is improved, and a magnetic field component that pushes an arc generated by a current flowing through the connection conductor vertical portion 7c (not shown) between the contacts is shielded by the pair of magnetic plates. .

In this embodiment, the magnetic pieces 10b and 10c and 10d and 10e adjacent to each other between the poles are collectively insulated by the pole gap cover 12g, and the magnetic pole pieces are separated by the same pole insulating cover. Also serves as insulation between the poles. In FIG. 13, the adjacent magnetic material pieces 10b and 10c and the magnetic material piece 1
0d and 10e are provided respectively, but the magnetic material pieces 10b and 10c are provided.
Alternatively, the magnetic pieces 10d and 10e may be integrated. As described above, by integrating components located between the poles of the respective poles with adjacent poles, the number of components is reduced, and the circuit breaker becomes more inexpensive.

[0061]

As described above, according to the present invention, a parallel conductor portion having a fixed contact at one end and substantially parallel to the closed movable contact and in which a reverse current flows is provided. Using a fixed contact having an anti-parallel conductor portion connected to the parallel conductor and arranged on the left and right sides of the parallel conductor portion and in which the movable contact in a closed state is substantially parallel and the current flows in the same direction,
A pair of magnetic plates are arranged on the movable contact side of the anti-parallel conductor so as to sandwich one end of the movable contact on the movable contact side from the left and right, and each magnetic member constituting the pair of magnetic plates Since the intervals between the magnetic plates and the magnetic arc extinguishing plate provided opposite to one end of the movable contact are made smaller than the intervals between the plates, as described above. Even when using a fixed contact structure that can reduce the height dimension of the circuit breaker, the effect of the magnetic field created by the current in the antiparallel conductor can be shielded, and the opening speed when breaking the short-circuit current is reduced. Improved current limiting performance is obtained,
Since the electromagnetic force for driving the arc to the arc-extinguishing plate is strengthened and the shut-off time is shortened, an effect is obtained in which the wear of the arc-extinguishing chamber at the time of interrupting is reduced.

An arc runner extends from one end of the parallel conductor, and when the direction in which the movable contact is separated from the fixed contact is upward, the fixed contact moves upward from the other end of the anti-parallel conductor. A connecting conductor vertical portion that extends in the direction and is connected to the terminal portion, and the connecting conductor vertical portion is provided with a slit at a portion that intersects a surface including a trajectory at the time of the opening and closing operation of the movable contact. Since a pair of magnetic plates are respectively opposed to a pair of conductors constituting a vertical portion of the connection conductor on the left and right sides of the slit, a magnetic field component for pushing back an arc between the contacts due to a current flowing through the vertical portion of the connection conductor to the arc. Thus, there is an effect that an object which can hardly cause interruption failure due to restriking can be obtained.

Further, an arc runner is extended at one end of the parallel conductor, and when the direction in which the movable contact is separated from the fixed contact is set to be upward, the fixed contact moves upward from the other end of the anti-parallel conductor. The connecting conductor has a vertical portion extending in the direction and connected to the terminal portion, and a magnetic shielding plate is arranged on the front surface of the connecting conductor portion on the fixed contact side. The magnetic field component pushed back in between can be more reliably shielded from the arc, and there is an effect that an interruption failure due to re-ignition hardly occurs.

Further, the connecting conductor vertical portion is provided with a slit at a portion which intersects with a plane including a locus at the time of the opening / closing operation of the movable contact, and a pair of conductors forming the left and right connecting conductor vertical portions of the slit. Since a pair of shielding plates made of a magnetic material are arranged on the front surface of the fixed contact side of the portion, a magnetic field component that pushes an arc due to a current flowing through the vertical portion of the connection conductor between the contacts is shielded from the arc, and a tip of the arc runner. In this case, there is an effect that a space in which the arc can be extended can be secured, and the interruption performance is hardly reduced due to insufficient arc extension.

Further, an arc runner is extended at one end of the parallel conductor portion, and the tip of the arc runner is outside the space surrounded by the pair of magnetic plates, and the direction in which the movable contact is separated from the fixed contact is determined. When the upper side, since the arc extinguishing plate of the magnetic material was arranged in the upper space of the tip of the arc runner,
The number of arc-extinguishing plates that can be installed can be increased, arc breaking and cooling by the arc-extinguishing plates can be improved, overload current interrupting performance and DC interrupting performance can be improved. There is an effect that a material that can reduce the rise in pressure can be obtained.

Further, the fixed contact has a connecting conductor vertical portion which extends upward from the other end of the antiparallel conductor and is connected to the terminal, and is one of a plurality of magnetic material arc extinguishing plates. Since the arc extinguishing plate of the portion is disposed between the connection conductor vertical portion and the pair of magnetic plates, a magnetic field component that pushes an arc generated by a current flowing through the connection conductor vertical portion back between the contacts is applied to the partial arc extinguishing plate. Thus, there is an effect that an object which can be shielded against an arc and in which interruption failure due to restriking hardly occurs is obtained.

Further, an arc runner is provided at one end of the parallel conductor portion, and a projection is provided at a portion extending from the side of the fixed contact of the insulating cover to the other end of the parallel conductor portion. The space enclosed by the arc runner is formed in a trumpet shape extending toward the arc runner side, so that the arc pressure is reflected by the trumpet-shaped insulating wall and the vapor pressure of the insulating wall allows the arc to be moved from the fixed contact to the arc runner in a shorter time. , The wear of the fixed contacts is reduced, and the interruption time is shortened, so that there is obtained an effect that a reliable one that can repeatedly perform the interruption operation can be obtained.

Further, an arc runner is extended at one end of the parallel conductor portion, and a portion from just beside the fixed contact of the insulating cover to the other end portion of the parallel conductor portion is heated by another portion. Because it is formed of a substance that generates a large amount of steam, the arc generated between the contacts can be pushed out of the fixed contact to the arc runner by the driving force due to the pressure difference caused by the insulator vapor, and the insulation cover This has the effect of making it difficult for the movable contact to be touched, and hardly causing interruption failure due to insulation breakdown through the surface of the insulating cover.

Further, an arc runner is extended at one end of the parallel conductor, and the arc runner, the movable contact, the fixed contact, a pair of magnetic plates and a magnetic extinguishing plate are housed in a housing. A flow path communicating from the space near the tip of the arc runner is formed between the inner surface of the housing and the surface of the pair of magnetic plates on the side opposite to the movable contact, so that the arc runner runs. This has the effect of suppressing an increase in pressure at the front of the arc, improving the arc traveling speed, and obtaining a material in which interruption failure due to the return of metal vapor generated from the arc between the contacts hardly occurs.

Further, of the magnetic material pieces having a plurality of poles and forming a pair of magnetic material plates for each pole, the magnetic material piece on the inter-electrode side is integrated with the adjacent magnetic material piece of the other pole. Therefore, the number of parts can be reduced, and an inexpensive product can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining an arc extinguishing unit of a circuit breaker according to Embodiment 1 of the present invention.

FIG. 2 is a diagram for explaining main components in the arc extinguishing unit according to the first embodiment of the present invention.

FIG. 3 is a diagram for explaining a circuit breaker according to Embodiment 1 of the present invention.

FIG. 4 is a diagram for explaining the positional relationship and operation of the main components according to the first embodiment of the present invention.

FIG. 5 is a diagram for explaining the positional relationship and operation of the main components according to the first embodiment of the present invention.

FIG. 6 is a diagram for explaining the positional relationship and operation of main components according to the second embodiment of the present invention.

FIG. 7 is a diagram for explaining the positional relationship and operation of main parts according to Embodiment 3 of the present invention.

FIG. 8 is a view for explaining a shielding plate according to a fourth embodiment of the present invention.

FIG. 9 is a diagram for explaining a pair of shielding plates according to a fifth embodiment of the present invention.

FIG. 10 is a diagram for explaining an insulating cover according to a sixth embodiment of the present invention.

FIG. 11 is a diagram for explaining an insulating cover according to a seventh embodiment of the present invention.

FIG. 12 is a diagram for describing an internal configuration of an arc extinguishing unit according to an eighth embodiment of the present invention.

FIG. 13 is a diagram for illustrating a multi-pole circuit breaker according to a ninth embodiment of the present invention.

FIG. 14 is a view for explaining a conventional circuit breaker.

FIG. 15 is a view for explaining a fixed contact structure of another conventional circuit breaker.

[Explanation of symbols]

1 movable contact, 2 movable contact, 5 fixed contact,
6 fixed contact, 7a parallel conductor, 7b anti-parallel conductor, 7c connection conductor vertical, 8 slit,
9 arcrunner, 10 pair of magnetic plates, 10
a, 10b, 10c, 10d, 10e, 10f Magnetic piece, 12 Insulation cover, 12d Projection, 12e
Part of insulating cover, 13 Arc extinguishing plate, 13b Part of arc extinguishing plate, 15a Terminal part, 21, 22 housing, 2
5 mechanism part, 30 shielding plates, 31 pair of shielding plates,
34 channel

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor: Masahiro Fushimi 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F-term within Mitsubishi Electric Corporation (reference) 5G027 AA03 BB07 BB09 BC07 BC14 5G030 AA08 DA01 DD01 DE02 FB13 XX00 YY07

Claims (10)

[Claims] A movable contact having a movable contact at one end;
A parallel conductor portion having a fixed contact that forms a contact pair with the movable contact at one end and having a substantially parallel and reverse current flowing with the movable contact in a closed state, and connected to the parallel conductor at one end; A fixed contact disposed on the left and right sides of the parallel conductor and having an anti-parallel conductor that is substantially parallel to the movable contact in a closed state, and through which current flows in the same direction; a fixed contact on the movable contact side of the anti-parallel conductor; A pair of magnetic plates arranged to sandwich one end of the movable contact from the left and right, an insulating cover covering a surface of the magnetic plate on the movable contact side, provided to face one end of the movable contact; A magnetic material extinguishing plate, a mechanism for closing or opening the movable contact from the fixed contact, wherein the arc extinguishing is performed based on an interval between the magnetic material plates constituting the pair of magnetic material plates. Make sure that the distance between the plate and each of the above magnetic plates is small. Circuit breaker according to symptoms. 2. An arc runner is provided at one end of the parallel conductor, and when the movable contact is separated from the fixed contact in an upward direction, the fixed contact moves upward from the other end of the anti-parallel conductor. A connecting conductor vertical portion that extends in the direction and is connected to the terminal portion, and the connecting conductor vertical portion is provided with a slit at a portion that intersects a surface including a trajectory at the time of the opening and closing operation of the movable contact. 2. The circuit breaker according to claim 1, wherein a pair of magnetic plates are opposed to a pair of conductors forming vertical portions of the left and right connection conductors of the slit. 3. An arc runner is provided at one end of the parallel conductor, and when the movable contact is separated from the fixed contact in an upward direction, the fixed contact moves upward from the other end of the anti-parallel conductor. 2. The circuit breaker according to claim 1, further comprising a connecting conductor vertical portion extending in the direction and connected to the terminal portion, wherein a magnetic shielding plate is disposed on a front surface of the connecting conductor portion on the fixed contact side. . 4. A slit is provided in the connecting conductor vertical portion at a portion that intersects a plane including a locus at the time of the opening and closing operation of the movable contact, and a pair of conductors forming the left and right connecting conductor vertical portions of the slit. 4. The circuit breaker according to claim 3, wherein a pair of shield plates made of a magnetic material are arranged on the front surface of the fixed contact side of the portion. 5. An arc runner is provided at one end of the parallel conductor portion. An end of the arc runner is located outside a space surrounded by a pair of magnetic plates, and has a direction in which a movable contact is separated from a fixed contact. 2. The circuit breaker according to claim 1, wherein a magnetic arc-extinguishing plate is disposed in an upper space of a tip portion of the arc runner when the arc-runner is positioned upward. 6. The fixed contact has a connection conductor vertical portion extending upward from the other end of the antiparallel conductor portion and connected to the terminal portion, and includes one of a plurality of magnetic material arc extinguishing plates. 6. The circuit breaker according to claim 5, wherein an arc-extinguishing plate of the portion is disposed between the connection conductor vertical portion and the pair of magnetic plates. 7. An arc runner is provided at one end of the parallel conductor, and a projection is provided at a position extending from the side of the fixed contact of the insulating cover to the other end of the parallel conductor. 2. A space surrounded by a trumpet extending toward the arc runner.
The circuit breaker as described. 8. An arc runner is provided at one end of the parallel conductor portion, and a portion extending from the side of the fixed contact of the insulating cover to the other end of the parallel conductor portion is heated by the arc heat from the other portion. The circuit breaker according to claim 1, wherein the circuit breaker is formed of a substance that generates a large amount of steam. 9. An arc runner is provided at one end of the parallel conductor portion. The arc runner, the movable contact, the fixed contact, the pair of magnetic plates and the magnetic extinguishing plate are housed in a housing. 2. A flow path is formed between the inner surface of the housing and a surface of the pair of magnetic plates on the side opposite to the movable contactor, the flow path communicating with a space near the tip of the arc runner. The circuit breaker as described. 10. A magnetic body piece having a plurality of poles and forming a pair of magnetic body plates for each pole, wherein a magnetic body piece on the inter-pole side is integrated with a magnetic body piece of an adjacent other pole. The circuit breaker according to claim 1, wherein