JP3389738B2 - Arc extinguishing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an arc extinguishing device applied to a circuit breaker or the like.

[0002]

2. Description of the Related Art The applicant of the present invention has proposed, as an arc extinguishing device for extinguishing an arc generated when a circuit breaker is cut off,
I applied for the one disclosed in No. 054324. As shown in FIGS. 17 and 18, this one has a fixed contact 1, a movable contact 8, a yoke 10 and a cooling member 13.

The fixed contact 1 is made of a conductive material, has a rectangular terminal portion 2 at one end, extends from the other end to the vicinity of the terminal portion 2, and has a fixed contact 6 near the tip thereof. The contact portion 3 and the fixed contact 6 have curved portions on both sides of the fixed contact 6, and the drive coil 4 is formed to connect between one end portion and the other end portion.

The movable contact 8 has a movable contact 9 on the lower surface of the tip end thereof which comes in contact with and separates from the fixed contact 6, and the fixed contact 6 and the movable contact 9 form a contact portion. The contact portion is inserted between the power source and the load, and the movable contact 8 is driven by an overcurrent detection circuit (not shown) that detects that an overcurrent has passed through the electric path, When an overcurrent passes through, the contact part opens.

The yoke 10 is made of a magnetic material and has both drive coils 4,
The facing pieces 10a, 10a and the connecting piece 10b are arranged so as to straddle four.
The magnetic flux generated by the drive coil 4 passes through each piece and between both contact points separated from the end surface of the facing piece. Further, in the opening of the yoke 10 on the side of the terminal portion 2, a heat radiating plate 11 extending from the facing pieces 10a, 10a and bent is formed. The heat radiating plate 11 has a plurality of long plate-shaped heat radiating fins 11b, 11b ... Arranged in two rows in parallel on the same plane through the vent holes 11a, 11a.

The cooling member 13 is made of an insulating material that generates a thermal decomposition gas when heated, and is formed so as to be exposed to the earth generated between the contacts 6 and 9 and to cover the inner surface of the yoke 10. It Further, 16 is an exhaust plate, and a plurality of exhaust ports 16a,
It has 16a ....

This arc extinguishing device operates as follows. When the contact portion is in the closed state, a magnetic field is generated around the drive coil 4 due to the current passing through the drive coil 4. Here, when the contact portion is opened, an arc is generated between the fixed contact 6 and the movable contact 9, and due to the Lorentz force which is an interaction between the arc and the magnetic field, the arc is generated by the terminal portion 2.
Is urged in the lateral direction. That is, the arc length is extended. Then, the cooling member 13 is heated by the arc to generate a pyrolysis gas, and the arc contacts the heat dissipation plate 11, whereby the arc is cooled, and the arc voltage increases due to the effect of the extension of the arc. Can make a rapid circuit break.

Further, the applicant of the present invention filed Japanese Patent Application No. 6-00843.
No. 5 has applied for the arc extinguishing device shown in FIG. This one basically has the same structure as the arc extinguishing device described above, except that the drive coil 4 of the fixed contact 1 extends from both sides of the terminal portion 2 in the same plane as that, and the other end thereof. It is formed so as to have approximately four semi-arc-shaped portions up to the portion 3b.

[0009]

In the former arc-extinguishing device, the arc voltage can be rapidly raised by the cooling member and the heat radiating plate, and the electric circuit can be cut off rapidly. The latter arc-extinguishing device reduces the gap between the contact part and the terminal part,
The fixed contact is economically constructed. However, in recent years, with the increase in the capacity of the load, there are many opportunities to interrupt a large current, and since the arc temperature is high when the large current is interrupted, it may take some time to interrupt the electric circuit. As a result, the deterioration of the components exposed to the arc is promoted.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an arc-extinguishing device having an economical structure and capable of rapidly interrupting even a large current. To do.

[0011]

In order to solve the above-mentioned problems, an arc extinguishing device according to a first aspect of the present invention is a substantially rectangular terminal portion provided at one end portion and the other end portion and the vicinity of the terminal portion. A fixed contact, which has a fixed contact near its tip and curved portions on both sides of the fixed contact, and a drive coil that connects one end and the other end, and the fixed contact A movable contact provided with a movable contact, and a yoke made of a magnetic material, which is substantially U-shaped by the facing piece and the connecting piece, and is arranged above the drive coil so that the magnetic flux from the drive coil passes through each piece. In an arc extinguishing device having a cooling member made of an insulating material formed so as to be exposed to an arc generated between both contacts and cover the inner surface of the yoke, a vent is provided in the opening on the terminal side of the yoke. It has a predetermined length in the direction of the major axis of the fixed contact. A plurality of radiator plates arranged in parallel with a septum is provided, covering the inner edge of the terminal portion to the cooling member made of an insulating material
A magnetic material provided with a covering piece and covering the covering piece with the covering piece.
A cooling plate made of steel is attached .

In the arc-extinguishing device according to a second aspect of the present invention, the ventilation holes of the heat radiation plates arranged in parallel according to the first aspect of the invention are gradually separated from each other in the direction of the flow path connecting the ventilation ports of the different heat radiation plates. It is arranged so as to be oriented.

An arc extinguishing device according to a third aspect is the following.
Connect the plurality of heat sinks described in 1 or 2 to the facing piece of the yoke.
A structure in which at least two pieces of knots are extended and bent
is doing.

According to a fourth aspect of the present invention, there is provided an arc-extinguishing device having a plurality of elongated plate-shaped heat radiating fins in which at least one of the heat radiating plates according to the first to third aspects is arranged side by side through a ventilation hole. It has a formed structure.

In the arc-extinguishing device according to a fifth aspect of the present invention, the vent hole of at least one of the heat radiating plates according to the first to third aspects is formed by a plurality of substantially circular holes.

According to a sixth aspect of the arc-extinguishing device, the drive coil of the fixed contact according to the first to fifth aspects extends from both side portions of the terminal portion in the same plane as the drive coil, and the other end portion thereof. It is formed so as to have approximately four semi-arc-shaped portions up to.

Further, the arc extinguishing apparatus according to claim 7, wherein the claim
In the contact part of the fixed contactor according to 6 , the opposing piece and the connecting piece form a substantially U shape, and the connecting piece abuts on the opposite side of the fixed contact of the contacting portion and extends in the direction of the terminal part, An arc traveling plate having fixed contacts is provided between the facing pieces.

[0018]

[0019]

According to the structure described in claim 1, the arc generated when the contact portion is opened is urged toward the terminal portion by the Lorentz force and stretched, and comes into contact with the plurality of heat radiating plates of the yoke to improve efficiency. Because it is cooled well, the arc voltage rises rapidly and the arc extinguishes.

Further, according to the structure of claim 1,
Contact with the cooling plate when the
Arc as the arc cools as the arc cools
The cooling of the arc is accelerated and the arc voltage increases sharply.
Click Ru can be extinguished.

Further, according to the configuration of claim 2, wherein, in addition to the operation of claim 1, the arc gas by arc extinguished with heat sink, through a flow path comprising a vent of the heat sink to be arranged Flow in a direction that gradually separates from the terminal,
It is difficult for the terminal portion to be adversely affected by the conductivity of the arc gas.

Further, according to the configuration of claim 3, wherein
In addition to the effect of item 1 or 2, since the plurality of heat dissipation plates are bent and formed from the facing pieces or the connecting pieces of the yoke, the number of parts is reduced and the assemblability is improved.

According to the structure of claim 4 , in addition to the effect of any one of claims 1 to 3 , a plurality of elongated plate-shaped heat radiation fins increase the surface area of the arc contact and the arc gas. Are easily discharged.

According to the structure of claim 5 , in addition to the effect of any one of claims 1 to 3, since the vent has a substantially circular hole, the surface area with which the arc contacts increases, and Easy to manufacture.

According to the structure of claim 6 , in addition to the operation of any one of claims 1 to 5, the terminal portion and the contact portion of the fixed contact are substantially flush with both side portions of the terminal portion. Since it extends inward and is connected by a drive coil that is curved in a substantially four-half arc shape up to the contact portion, the gap between the terminal portion and the contact portion when the fixed contact is expanded into a flat plate shape. Can be made small.

Further, according to the configuration of claim 7, wherein, in addition to the effect of claim 6, the arc to migrate to the connecting piece of the arc running plate than the contact portion, the arc is likely to further stretched.

[0027]

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The basic construction of the present invention will be described below with reference to FIGS.
It will be described based on. Members having the same basic functions as those described in the conventional example are designated by the same reference numerals.

FIG . 1 is an exploded perspective view of the arc extinguishing device. The arc extinguishing device comprises a fixed contact 1, a movable contact 8, a yoke 10, a cooling member 13, and an arc traveling plate 14.

The fixed contact 1 has a terminal portion 2 at one end portion, a contact portion 3 extending from the other end portion to the vicinity of the terminal portion 2, and a drive coil 4 connecting between one end portion and the other end portion. And is formed by bending a plate-shaped conductive material.

The terminal portion 2 has a substantially rectangular plate shape, and a terminal screw 5 for connecting an electric wire is screwed into an end portion thereof. The contact portion 3 is substantially parallel to the terminal portion 2 and is provided at a position slightly separated in the longitudinal direction. A fixed contact 6 is provided on the upper surface, and is a traveling portion 7 through which an arc travels from the fixed contact 6 to the tip 3a.

The drive coil 4 is in contact with the inner edge 2a of the terminal portion 2
The outer edge 3b of the contact portion 3 is connected to the outer edge 3b of the contact portion 3 by extending from both side portions of the terminal portion 2 in substantially the same plane as the fixed contact 6 is sandwiched. It is configured by bending a pair of long flat plates so as to have a curved portion in an arc shape.

The movable contact 8 has a movable contact 9 on the lower surface of the tip end thereof, which comes into contact with and separates from the fixed contact 6, and the fixed contact 6 and the movable contact 9 form a contact portion. The contact portion is inserted between the power source and the load, and the movable contact 8 is driven by an overcurrent detection circuit (not shown) that detects that an overcurrent has passed through the electric path, When an overcurrent passes through, the contact part opens. Further, the upper end of the drive coil 4 is located below the position of the movable contact 9 when the movable contact 9 is farthest from the fixed contact 6. That is, the distance from the fixed contact 6 to the upper end of the drive coil 4 is set smaller than the maximum opening distance of the contact portion.

The yoke 10 is provided above the drive coils 4 with a magnetic material so as to straddle both drive coils 4, and a pair of opposed pieces 10a, 10a provided on both sides of the movable contact 8 and The facing pieces 10a, 10a are integrally and continuously formed with a connecting piece 10b that magnetically short-circuits between the upper ends of the facing pieces 10a, 10a, and the cross-sectional shape is formed in a substantially U-shape that opens downward. Then, the magnetic flux generated by the drive coil 4 passes through each piece and between both contacts opened from the end surface of the facing piece 10a.

Further , the opening of the yoke 10 on the side of the terminal portion 2 is provided with two heat radiating plates 11 and 12 arranged side by side in the longitudinal direction of the fixed contact 1 with a space of about 1 mm. This heat sink 11,
12 is for cooling the arc, and vents 11a, 11a,
Long plate-shaped heat radiation fins 11 arranged side by side via 11a, 12a, 12a
b, 11b, 11b, 11b, 12b, 12b, 12b. .., 12b, .. The seven radiating fins 11b, ..., 12b, .. extend from the facing pieces 10a, 10a and are bent and positioned in the opening on the side of the terminal portion 2.

The cooling member 13 is made of an insulating material, covers the inner peripheral surface of the yoke 10 so as to be exposed to an arc described later, and is provided above the fixed contact 1.
As the insulating material, a material that generates a thermal decomposition gas by arc heat, such as melamine resin or polymethylpentene resin, is used. That is, the arc is cooled by the pyrolysis gas to quickly extinguish the arc. The cooling member 13 includes a partition piece 13a for partitioning the contact portion 3 and the drive coil 4 and a contact portion 3a.
13b that covers a part of the drive coil and a protrusion that covers the upper surface of the drive coil 4
13 c and a covering piece 13 d that covers the inner edge 2 a of the terminal portion 2.
Therefore, the arc generated when the contacts are opened
2, the transfer to the contact portion 3, the drive coil 4 and the like is prevented. Note that 13e is an exhaust port, which is an outlet for exhausting the arc.

The arc traveling plate 14 is one on which an arc travels, and is formed in a substantially U-shape by the opposing pieces 14a, 14a and the connecting piece 14b, and the connecting piece 14b contacts the fixed contact 6 of the contact portion 3 on the opposite side. The fixed contact 6 is attached to the contact portion 3 of the fixed contact 1 so that the fixed contact 6 is positioned between the facing pieces 14a, 14a while being in contact with and extending in the direction of the terminal portion 3.

Further , in FIG. 3, reference numeral 15 is a circuit breaker main body, which is a substantially box-like body for accommodating the respective components of the arc-extinguishing device and is made of resin or the like. 16 is an exhaust plate through which arc gas of the arc extinguished by the arc extinguishing device flows,
It is formed in a flat plate shape having a plurality of exhaust ports 16a, 16a ... And is attached to the circuit breaker main body 15. 17 is a crimp terminal, an electric wire
18 is connected to the terminal screw 5 of the terminal portion 2 of the fixed contact 1.

Next, it will be described with reference to FIG. 3, the operation of the above configuration. When the fixed contact 6 and the movable contact 9 of the contact portion are opened, an arc Z1 is generated between the contacts. The arc Z1 receives a Lorentz force in the direction A due to the magnetic flux generated by the drive coil 4, and one end of the arc Z1 has a contact portion.
It moves from the traveling portion 7 of 3 toward the tip of the connecting piece 14b of the arc traveling plate 14 and extends (Z2). As the contact opening distance increases, the arc further extends (Z3) and the yoke 10
Is extended toward the opening by and comes into contact with the heat dissipation plates 11 and 12 (Z4). As a result, the arc is composed of two heat sinks whose metal is in the positive column part ZY, which has the highest temperature.
As it is cooled by 11, 12 and expands, the arc voltage rises sharply, extinguishes the arc, and the electric circuit is cut off. Then, the arc gas generated by extinguishing the arc is vented through the vents 11a, ..., 12a ...
It is discharged to the outside of the circuit breaker body 15 through 6a, 16a ....

Even if the arc current is large, this arc extinguishing device can efficiently extinguish the arc in a short time because it is efficiently cooled by the heat radiation plates 11 and 12 arranged in parallel. Further, since the temperature of the arc gas can be lowered by the heat dissipation plates 11 and 12, the conductivity of the arc gas is reduced accordingly,
The conductivity of the space near the terminal portion 2 can be reduced. Therefore, in a circuit breaker having a plurality of contact portions, even when an arc occurs due to a short-circuit current flowing to an adjacent contact portion to open the contact, the conductivity in the space near the terminal portion 2 is low, It is possible to prevent an arc bridging phenomenon between the terminal parts 2 connected to the parts, that is, a so-called short circuit between electrodes. When the electric resistance of the space in the vicinity of the terminal portion 2 was measured, by providing the heat dissipation plates 11 and 12 having the heat dissipation fins 11b and 12b extending from the facing pieces 10a and 10a as in the present invention,
Compared to the case where the heat radiation fin is extended from one facing piece,
The electrical resistance is 3 to 5 times higher.

[0041] Further, since the arc gas is cooled by the heat radiating plate 11, the temperature rise of the gas surrounding the arc is suppressed, the damage by suppressing the pressure rise in the arc extinguishing device with the expansion of the gas Can be suppressed and the reliability of the arc extinguishing device can be improved.

Another arc-extinguishing device having the basic structure of the present invention is shown.
It will be described with reference to FIGS. 4 and 5. This arc extinguishing device
The structure of the heat dissipation plates 11 and 12 is different from that of the arc extinguishing device shown in FIGS.

The heat radiating plates 11 and 12 are shown in FIGS.
Like the arc extinguishing device , in the opening on the side of the terminal portion 2 of the yoke 10,
The fixed contacts 1 are arranged side by side in the direction of the major axis of the fixed contact 1 with a space of about 1 mm, and the cross-sections of the heat dissipating fins 11b, ..., 12b, ... It has a letter shape. Specifically, as shown in FIG. 5, the three radiating fins 11b, 11b, 12b near the connecting piece 10b are arranged so as to be substantially orthogonal to the terminal portion 2 of the fixed contact 1, and The five radiating fins 11b, 11b, 12b, 12b, 12b near the part 2 are
And an angle θ of less than 90 degrees. Further, the ventilation holes 11a formed by the radiation fins 11b, ..., 12b ,.
…, 12a… are many flow paths connecting the different heat sinks 11, 12
But it is arranged so as to be gradually away direction from the terminal unit 2.

In this arc-extinguishing device, the arc gas generated by extinguishing the arc passes through the vent holes 11a, ... The conductivity of the space in the vicinity can be further reduced to further suppress the inter-electrode short circuit phenomenon.

[0045] will be described with reference to FIGS. 6 and 7 a basic configuration of the present invention illustrating yet another arc extinguishing device. This arc extinguishing device also differs from the arc extinguishing device shown in FIGS. 1 to 3 in the structure of the heat dissipation plates 11 and 12.

The heat radiating plate 11 has the same structure as that shown in FIGS.
Similar to the arc device , the four heat radiation fins 11b, 11b, 11b, 11b, which extend from the facing piece 10a and are bent and positioned in the opening on the side of the terminal portion 2, are arranged in parallel. Have. The heat dissipation plate 12 extends from the connecting piece 10b,
It is bent and positioned inside the heat dissipation plate 11 at the opening on the side of the terminal portion 2, and has a plurality of vent holes 12a, 12a, ... Which are substantially circular holes and are arranged side by side in two rows.

In this arc extinguishing device, since the vent holes 12a, 12a, ... Are substantially circular holes, the surface area in contact with the arc is increased to enhance the cooling performance, and the arc can be extinguished rapidly. At the same time, the conductivity of the space in the vicinity of the terminal portion 2 can be further reduced to further suppress the inter-electrode short circuit phenomenon. Further, since the vent holes 12a, 12a, ... Are easily manufactured, the productivity of the heat dissipation plate 12 can be improved.

[0048] Yet another extinguishing apparatus a basic configuration of the present invention
Will be described with reference to FIGS. 8 and 9. In this arc extinguishing device , the structure of the heat dissipation plates 11 and 12 is the same as that shown in FIGS.
It is different from the arc device .

The heat radiating plate 11 extends from the facing piece 10a and is bent to be positioned at the opening on the side of the terminal portion 2. It is a plurality of substantially circular holes arranged in a grid. It has ventilation holes 11a, 11a .... The heat radiating plate 12 is also extended from the facing piece 10a and is bent and positioned inside the heat radiating plate 11 at the opening on the side of the terminal portion 2, and is a substantially circular hole and is arranged in a grid pattern. Has a plurality of vent holes 12a, 12a ,.

In this arc extinguishing device, since the vent holes 11a, ..., 12a, ... Of the two heat radiating plates 11, 12 are substantially circular holes, the surface area in contact with the arc is increased and the cooling performance is further enhanced. It is possible to extinguish the arc rapidly and the terminal part 2
The electrical conductivity of the space in the vicinity of can be further reduced to further suppress the inter-electrode short circuit phenomenon. Also, vents 11a, ..., 12a,
Is easy to manufacture, the productivity of the heat dissipation plates 11 and 12 can be improved.

[0051] Yet another of the arc-extinguishing system the basic structure of the present invention
Will be described with reference to FIGS. 10 to 12. This arc extinguishing device is provided with three heat radiating plates 11, 12, 21.

The heat radiating plate 11 extends from the facing piece 10a, is bent and is positioned in the opening on the side of the terminal portion 2, and has four long plate-like heat radiating fins 11b, 11b, which are arranged in parallel. 11
b, 11b. The heat radiating plate 12 extends from the facing piece 10a and is bent so that the heat radiating plate 11 has an opening on the side of the terminal portion 2.
And has three long plate-shaped heat radiation fins 12b, 12b, 12b arranged side by side. The heat sink 21 is a connecting piece 10b.
A plurality of vent holes 21a, 21a which are extended further and are bent and positioned outside the heat dissipation plate 11 of the opening on the side of the terminal portion 2 and which are substantially circular holes and arranged in two rows. , ... have.

In this arc-extinguishing device, the three heat-dissipating plates 11, 12, 21 further increase the surface area in contact with the arc gas, so that the cooling performance is further enhanced and the arc can be extinguished rapidly. Further, it is possible to further reduce the conductivity of the space in the vicinity of the terminal portion 2 to further suppress the inter-electrode short circuit phenomenon.

[0054] Yet another extinguishing apparatus a basic configuration of the present invention
Will be described with reference to FIGS. 13 and 14. This arc extinguishing device is the same as the arc extinguishing device shown in FIGS. 10 to 12, except that the position of the heat dissipation plate 21 is changed. The heat sink 21 is a terminal
It is bent and formed so as to be positioned inside the heat dissipation plate 12 of the opening on the side of 2.

[0055] The arc-extinguishing apparatus, large heat dissipation plate of surface area 21
Since the arc contacts first, the cooling of the arc can be promoted and the arc voltage can be rapidly increased.

An embodiment of the present invention will be described with reference to FIGS. 15 and 16. In this embodiment, the extinguishing device shown in FIGS. 1 to 3 is formed to promote cooling of the arc.

[0057] 19 in the cooling plate is obtained by forming a substantially C-shaped cross section by a magnetic material is formed by bending a flat plate, it is attached to the cover strip 13d of the cooling member 13. Specifically, as shown in FIG. 16, it has a length that covers the entire covering piece 13d and is hooked and fixed to one end 13f of the cooling member 13.

In this arc extinguishing device, the arc is cooled and the arc is divided by coming into contact with the cooling plate 19 when the arc extends, so that the cooling of the arc is promoted and the arc voltage rapidly increases. The arc can be extinguished.

Although the heat radiating plate is formed by bending the facing piece or the connecting piece of the yoke, it may be attached to the yoke as a separate member. Further, the structure of the heat dissipation plate is provided with long plate-shaped heat dissipation fins and circular ventilation holes, but the invention is not limited to the structure itself. What is necessary is just to arrange | position so that it may be arranged in the longitudinal direction.

[0060]

In the arc-extinguishing device according to the first aspect of the present invention, the arc generated when the contact portion is opened is urged toward the terminal portion side by the Lorentz force and stretched, and comes into contact with the plurality of heat radiation plates of the yoke. Because of the efficient cooling, the arc voltage rapidly rises and the arc extinguishes, so that the circuit is rapidly cut off even with a large current.

Further, in this case, a cooling member made of an insulating material is used.
The arc is not only cooled by the pyrolysis gas generated
Contacts the cooling plate made of magnetic material when the arc expands
By doing so, the arc is cooled and the arc
Because it is divided, the cooling of the arc is accelerated and the arc voltage is increased.
Suddenly increases, Ru can be extinguishing the arc.

In addition to the effect of claim 1, the arc extinguishing device according to claim 2 allows the arc gas extinguished by the arc of the heat radiating plate to pass through a flow path formed by the vent holes of the heat radiating plates arranged in parallel. Then, since the current gradually flows away from the terminal portion, the adverse effect of the conductivity of the arc gas is less likely to be exerted on the terminal portion, so that the inter-electrode short circuit at the terminal portion can be prevented.

Further, the arc extinguishing device according to claim 3 is the following:
In addition to the effect of 1 or 2, since the plurality of heat dissipation plates are bent and formed from the facing pieces or the connecting pieces of the yoke, the number of parts is reduced and the assembling property is improved, so that the productivity is improved.

In addition to the effect according to any one of claims 1 to 3 , the arc extinguishing device according to claim 4 increases the surface area of the arc contacting by the plurality of elongated plate-shaped heat radiation fins, and the arc gas. Since it becomes easier to discharge, the arc extinguishing performance can be further improved and the electric circuit can be cut off rapidly.

Further, in the arc extinguishing device according to claim 5 , in addition to the effect according to any one of claims 1 to 3, since the vent has a substantially circular hole, the surface area with which the arc contacts increases, and Since it is easy to manufacture, the arc extinguishing performance can be further enhanced, the electric circuit can be cut off rapidly, and the productivity can be improved.

Further, in the arc extinguishing device according to a sixth aspect of the present invention, in addition to the effect of any one of the first to fifth aspects , the terminal portion and the contact portion of the fixed contact are substantially flush with both side portions of the terminal portion. Since it extends inward and is connected by a drive coil that is curved in a substantially four-half arc shape up to the contact portion, the gap between the terminal portion and the contact portion when the fixed contact is expanded into a flat plate shape. Since it can be made small, it can be formed economically.

[0067] Also, the arc extinguishing apparatus according to claim 7, wherein the claim
In addition to the effect of 6 , the arc moves from the contact portion to the connecting piece of the arc traveling plate, so that the arc is more easily stretched, so that the arc extinguishing performance can be further enhanced and the electric path can be rapidly cut off.

[0068]

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an arc extinguishing device showing a basic configuration of the present invention.

FIG. 2 is a development view of a yoke of the arc extinguishing device.

FIG. 3 is a sectional view of the arc extinguishing device when an arc is generated.

FIG. 4 is a perspective view of a yoke of another arc extinguishing device showing a basic configuration of the present invention.

FIG. 5 is a sectional view of the arc extinguishing device when an arc is generated.

6 is a perspective view of the yoke of further extinguishing devices showing a basic configuration of the present invention.

FIG. 7 is a sectional view of the arc extinguishing device when an arc is generated.

FIG. 8 is a perspective view of a yoke of still another arc extinguishing device showing a basic configuration of the present invention.

FIG. 9 is a sectional view of the arc extinguishing device when an arc is generated.

FIG. 10 is a perspective view of a yoke of still another arc extinguishing device showing a basic configuration of the present invention.

FIG. 11 is a development view of a yoke of the arc extinguishing device.

FIG. 12 is a sectional view of the arc extinguishing device when an arc occurs.

FIG. 13 is a perspective view of a yoke of still another arc extinguishing device showing a basic configuration of the present invention.

FIG. 14 is a sectional view of the arc extinguishing device when an arc is generated.

FIG. 15 is an exploded perspective view of an arc extinguishing device showing an embodiment of the present invention.

FIG. 16 is a sectional view of the arc extinguishing device when an arc is generated.

FIG. 17 is an exploded perspective view of an arc extinguishing device showing a conventional example of the present invention.

FIG. 18 is a perspective view of the arc extinguishing device during assembly.

FIG. 19 is an exploded perspective view of an arc extinguishing device showing another conventional example.

[Explanation of symbols]

1 Fixed contact 2 terminals 3 contact part 4 drive coil 5 terminal screws 6 fixed contacts 7 running section 8 Movable contact 9 movable contacts 10 York 11 Heat sink 12 Heat sink 13 Cooling member 14 Arc traveling board 15 Circuit breaker body 19 Cooling plate 21 Heat sink

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akemi Shiokawa 1048, Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Works, Ltd. (56) References JP-A-6-68773 (JP, A) JP-A-6-20548 ( JP, A) JP 6-314537 (JP, A) JP 7-320624 (JP, A) JP 56-162434 (JP, A) JP 60-202632 (JP, A) JP 55-53035 (JP, A) JP-B 6-30211 (JP, B2) JP 63-13642 (JP, Y1) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01H 71 / 00-83/22 H01H 9/30

Claims (7)

(57) [Claims] 1. A substantially rectangular terminal portion provided at one end,
A contact portion extending from the other end to the vicinity of the terminal portion and provided with a fixed contact near its tip, and a drive coil having curved portions on both sides of the fixed contact and connecting one end and the other end A fixed contact, a movable contact that has a movable contact that contacts the fixed contact, and an opposing piece and a connecting piece that are approximately U-shaped and are arranged above the drive coil so that the magnetic flux from the drive coil passes through each piece. An arc extinguishing device having a yoke made of a magnetic material and a cooling member made of an insulating material formed to cover an inner surface of the yoke while being exposed to an arc generated between both contacts, and a terminal of the yoke. A plurality of heat radiating plates, each having a vent, are arranged side by side at a predetermined interval in the substantially major axis direction of the fixed contact in the opening on the part side, and the cooling member made of an insulating material has a terminal part. Provide a covering piece that covers the inner edge of the An arc extinguishing device, characterized in that a cooling plate made of a magnetic material for covering the piece is attached. 2. The ventilation holes of the heat radiation plates arranged in parallel are arranged so that the direction of the flow path connecting the ventilation holes of the different heat radiation plates gradually separates from the terminal portion. Arc extinguishing device according to 1. 3. The arc extinguishing device according to claim 1, wherein the plurality of heat radiation plates are bent and formed by extending from at least two pieces of a yoke facing piece and a connecting piece. 4. The arc extinguishing system according to claim 1, wherein at least one of the heat radiating plates is formed to have a plurality of long plate-shaped heat radiating fins arranged in parallel through a ventilation hole. apparatus. 5. The arc extinguishing device according to claim 1, wherein the vent hole in at least one of the heat radiating plates is formed by a plurality of substantially circular holes. 6. The drive coil of the fixed contact is formed so as to extend from both sides of the terminal portion in the same plane as the terminal coil and to have a substantially four-half arc-shaped portion up to the other end. The arc-extinguishing device according to claim 1, which is characterized in that. 7. The contact portion of the fixed contact is formed in a substantially U shape by a facing piece and a connecting piece, and the connecting piece abuts on a side opposite to the fixed contact of the contact portion and extends in the direction of the terminal portion. The arc extinguishing device according to claim 6, further comprising an arc traveling plate having a fixed contact located between the facing pieces.