JPH081551Y2 - Arc breaker for circuit breaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an arc extinguishing device for a circuit breaker or a breaker, and more particularly to improvement of its arc extinguishing ability.

[Conventional technology]

FIG. 7 shows, for example, No. 52-2166 and No. 71051.
FIG. 8 is a partial cross-sectional side view of a conventional circuit breaker or circuit breaker equipped with an arc extinguishing device of the type disclosed in No. 5, FIG. 8 is a plan view of the arc extinguishing device of FIG. Shiya disconnector case,
(2) is a movable contactor connected to an opening / closing mechanism (not shown), (201) is its contact point, (3) is the fixed contactor (301) its contact point, (4) is the above-mentioned when current is turned on or off. Contact (201),
Arc extinguishing device for extinguishing arc (A) generated between (301),
(5) is an external conductor, (6) is an external connection terminal for connecting the external conductor (5) to the fixed contact (3),
Reference numeral 1) is a screw for attaching the external connection terminal (6) to the fixed contactor (3), and reference numeral (602) is a screw for fastening and holding the external conductor (5) to the external connection terminal (6). (7) is an insulating partition provided between the arc extinguishing device (4) and the external connection terminal (6), and (8) is an arc runner provided on the fixed contactor (3).

The arc-extinguishing device (4) includes a plurality of substantially U-shaped arc-extinguishing plates (401) that are open to the side of the contacts (2) and (3), and a side support plate (40
2) are held in a stacking relationship at intervals in the vertical direction by (2), and (403) are both legs of each arc extinguishing plate (401). Reference numeral (9) is an insulating plate made of an inorganic material such as mica or asbestos, which is provided inside both legs (403) and entirely covers both legs (403) of the arc extinguishing plate (401).

Next, the operation will be described. When a large current such as an overcurrent flows while the contacts (2) and (3) are closed and the contacts (201) and (301) are also closed, the movable contact (2) is in stationary contact via the opening / closing mechanism. Move away from the child (3) and contact (20
1) and (301) are separated to generate an arc (A) between the contacts (201) and (301). At that time, the arc (A) is driven toward the back of the arc extinguishing plate (401) by the electromagnetic action of the magnetic flux formed through the arc extinguishing plate (401) by the arc current and the arc current to be stretched and extinguished. It is divided by the arc plate (401), cooled, and extinguished. During such arc extinction, the insulating plate (9) prevents the arc extinguishing plate (401) from being melted and scattered by arc heat, and at the same time, the above-mentioned Japanese Utility Model Publication No. 51-2166 and Japanese Utility Model Publication No. 52166.
Although it is not positively described in the −71051 publication, the arc is prevented from flying from the contact (201) or the tip or side of the movable contact (2) to the leg (403) of the arc extinguishing plate (401). Prevent, the arc flies to the leg (403) and stays there,
It also has the function of preventing unintentional disconnection.

However, since the insulating plate (9) is made of an inorganic material, the surface of the insulating plate (9) is in a molten state due to arc heat during breaking and breaking, so that the insulation recovery force between the contacts at the current zero point is small. In addition, there is no possibility of mass production, there is no mass productivity, the manufacturing cost is high, the hardness is high, it is fragile, and it is easily damaged by vibration and shock. Furthermore, when an arc occurs, the surface of the insulating plate (9) is cracked. There was a weak problem with the heat shock.

Then, in order to solve such a problem, Japanese Patent Application No. 62-
Insulating plate (9) in 91202 (JP-A-63-257138)
It has been proposed to form the with a resin material. Since the insulating plate made of such a resin material does not have a surface melted by arc heat as in the case of an inorganic material, it has high surface resistance during combing and cutting, good cutting performance and inexpensive. Since it can be mass-produced, it is less likely to be damaged even when subjected to vibration and shock, and has a strong advantage in heat shock due to arc.
In addition, when the resin material is heated by the arc heat and its temperature rises, an insulating decomposition gas is generated, and when the decomposition gas is generated, the energy of the arc is deprived by the decomposition gas and at the same time the arc is cooled and further decomposed. The arc-extinguishing performance is improved as compared with the case where the inorganic insulating plate (9) is provided because the contact opening speed of the switching contacts (2) and (3) is increased by the increase of the gas pressure.

The resin material applied for use as the insulating plate (9) is described in Japanese Patent Application No. 62-91202, but it will be described here again.

Resin materials are roughly classified into thermoplastic resins and thermosetting resins, and when the advantages of using them for the insulating plate (9) are compared between thermoplastic resins and thermosetting resins, they are generally moldable and vibration resistant. The thermoplastic resin is superior to the thermosetting resin in terms of impact resistance and heat shock resistance, and the thermosetting resin is superior to the thermoplastic resin in terms of surface resistance. There is no great difference in the amount of decomposed gas generated. In addition, it is lightweight,
Thermoplastic resin is superior to thermosetting resin in that it does not easily generate powder even if friction with the arc-extinguishing plate is generated due to vibration or impact, and occasionally has good moisture resistance. The thermosetting resin is superior in that the expansion force is small. Furthermore,
Specifically, examples of the thermoplastic resin suitable for forming the insulating plate (9) include silicone resin and polyester resin, and examples of the thermosetting resin include silicone resin, polyester resin, epoxy resin, Mention may be made of phenolic resins. In addition to the general characteristics described above, the silicone resin does not substantially deposit carbon on the surface of the insulating plate (9) even when it decomposes upon contact with an arc to generate a decomposed gas. It has an advantage that there is no fear of insulation failure or insulation deterioration, and is superior to other resin materials in this respect.

Further, in the case of polyester resin or phenol resin, the mechanical strength can be increased by mixing glass fiber therein. The structure of the insulating plate (9) includes an ordinary resin molded body and a fiber sheet. However, even if the insulating sheet (9) is formed of the same resin material, the fiber sheet has a decomposition gas amount larger than that of a normal resin formed body. It has many advantages such as high moldability and very easy press punching.

[Problems to be solved by the invention]

The conventional circuit breaker and circuit breaker are configured as described above, and the arc (A) is moved to the back of the arc extinguishing device (4) by the electromagnetic driving force generated by the electromagnetic action of the arc current and the magnetic flux formed by the arc current. The arc (A) is driven to the back of the arc extinguishing device (4) because the electromagnetic driving force is large when a large current such as a short-circuit current is turned on or off. The arc is extinguished, but when a relatively small current such as an overload current is turned on or off, the electromagnetic driving force is weak and the arc extinguishing device (4) is not driven to the inner side, and both sides are made of an inorganic material and a resin. Insulating plate (9) regardless of material
The arc (A) cannot be extinguished without being driven to the inner part of the arc extinguishing device (4) because the arc (A) cannot cool the leg (403) of 1) and the cooling effect is low. There was a problem.

This invention was made in order to solve such problems of the conventional ones, and a circuit or a circuit breaker that can surely extinguish the arc even when a relatively small current such as an overload current is cut or disconnected. An object is to provide an arc device.

[Means for solving problems]

The arc-extinguishing device according to the present invention cuts out a part of the edge of the insulating plate on the side of the opening / closing contact and exposes the leg of the arc-extinguishing plate to the arc at this cutout portion, while it is opposite to the opening / closing contact. The inner part on the side covers the legs of the arc-extinguishing plate as a whole.

[Action]

In this invention, the arc extinguishing plate leg portion exposed by the cutout of the insulating plate comes into contact with the arc to cool it, whereas the arc extinguishes between the switching contacts in the non-cutout portion of the insulating plate. Prevents jumping in short-circuit condition by following the legs of the board. In particular, when the breaking current is relatively small like the overload current, the electromagnetic driving force of the arc is weak toward the back of the arc-extinguishing plate, but the back part of the insulating plate is the leg of the arc-extinguishing plate. Since the back part of the arc-extinguishing plate is entirely covered, the arc does not contact and stay in the legs of the arc-extinguishing plate in a short-circuited state at the back part,
Therefore, the arc extinguishing ability of a small current is remarkably improved by the synergistic effect of the arc cooling effect due to the cutout portion of the insulating plate and the arc retention preventing effect at the inner side.

[Example of device]

An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a partially broken perspective view of an arc extinguishing device for a circuit breaker and a circuit breaker according to an embodiment of the present invention, FIG. 2 is a plan view of FIG. 1, and FIG. 3 is a line III- of FIG. FIG. 3 is a cross-sectional view taken along line III, in which the same parts as those of the conventional one are designated by the same reference numerals and the description thereof is omitted.

In the figure, (9A) is an insulating plate corresponding to (9) of the conventional one, which is made of an appropriate insulating material regardless of whether it is an inorganic material or a resin material.
1) It is fixed to both legs (403) by inserting it between the protrusion (405) formed on the inner part (404) of the rear part (404) and both legs (403) and caulking the protrusion (405).

The edge portion (901) of the insulating plate (9A) on the side of the opening / closing contacts (2), (3) is notched in the central portion (904) except for the upper portion (902) and the lower portion (903). Both legs (403) of the arc-extinguishing plate (401) are exposed to the arc (A) in the opened central portion (904). Both legs (403) of the upper part (902) and the lower part (903) are covered with an insulating plate (9A) so as not to come into contact with the arc (A). Further, the inner part of the insulating plate (9A) opposite to the opening / closing contacts (2) and (3) covers the inner part of the leg (403) of the arc extinguishing plate (401) as a whole. .

Thus, when a relatively small current such as an overload current is cut off or turned off, the electromagnetic driving force for driving the arc (A) toward the back of the arc extinguishing device (4) is small, and accordingly, the arc (A).
Is not driven toward the back of the arc-extinguishing device (4) and often stays in the vicinity of the entrance, but while staying in the vicinity of the entrance in this way, the exposed leg (403) Contacted and effectively cooled. On the other hand, in the upper part (902) and the lower part (903) where the arc (A) is the closest to the switching contacts (2) and (3) and the arc (A) is most likely to fly, both legs (403) are connected to the arc (9A) by the insulating plate (9A). Since it is covered with respect to A), the arc (A) does not fly to these parts, and the arc (A) passes between the open / close contacts (2) and (3) and the leg of the arc extinguishing plate (401). Division (403)
It is prevented from flying in a short-circuited state. As described above or when the breaking current is relatively small like the overload current, the arc (A) toward the back of the arc extinguishing plate (401).
Inevitably the electromagnetic driving force of the arc is reduced, but in the inner part of the arc extinguishing plate (401), the insulating plate (9A) entirely covers the legs (403) of the arc extinguishing plate (401). Therefore, the arc is prevented from coming into contact with and staying on the leg (403) in the short-circuited state. Therefore, the cooling due to the contact with the exposed portion of the leg portion (403) described above and the prevention of flying in the short circuit state through the leg portion (403) between the opening / closing contacts (2) and (3) are prevented. Therefore, the arc (A) is extinguished even if it is not driven to the back of the arc extinguishing device (4). In addition, even when a large current such as a short-circuit current is turned on or off, the exposed portion of the legs (403) of the arc extinguishing plate (401) naturally has the effect of cooling the arc (A) at a station. It goes without saying that performance will also improve.

In addition, (406) is a protrusion formed outward on both legs (403) of each arc extinguishing plate (401), and (407) is formed on the side support plate (402) corresponding to the protrusion (406). It is a hole that holds the arc extinguishing plate (401) in a stacking relationship with a gap by fitting the protrusion (406) into the hole (407) and then caulking the protrusion (406). is there.

Another embodiment of the present invention is shown in FIG. 4 in a partially cutaway perspective view. This embodiment differs from the previous ones in that the upper portion (902) of the edge portion (901) of the insulating plate (9A) is left and the other portions, that is, the central portion (904) and the lower portion (903) are notched. It is a point. Thus, in the upper part (902), the leg portion (403) of the arc extinguishing plate (401) is covered by the insulating plate (9A) so as not to come into contact with the arc (A), and the notched portion becomes the arc (A). Will be exposed. In this embodiment, the arc (A) does not fly to the leg (403) of the upper arc extinguishing plate (401), and the arc (A) moves to the tip of the movable contact (2) and the arc (A). The extension of the legs is promoted and the legs (403)
The arc (A) is cooled better because there are many exposed parts of the arc.

Yet another embodiment of the present invention is shown in FIG. 5 in a partially cutaway perspective view. This embodiment differs from the previous two embodiments in that the lower part (903) of the edge part (901) of the insulating plate (9A) is left and the other parts, namely the upper part (902) and the central part (904) are left. It is a cutout point. Thus, in the lower part (903), the leg portion (403) of the arc extinguishing plate (401) is covered by the insulating plate (9A) so as not to come into contact with the arc (A), and the notched portion becomes the arc (A). Will be exposed. In this embodiment, the movable contact (2) does not fly from the fixed contact (3) to the lower leg (403) immediately after the movable contact (2) is separated from the fixed contact (3), and the arc (A) is an arc runner ( It is easy to drive the arc extinguishing device (4) toward the back along 8), the extension of the arc (A) is promoted, and the exposed portion of the leg (403) is large, so that the arc (A) is better. To be cooled.

Further, another embodiment of the present invention is shown in a partially cutaway perspective view in FIG. This embodiment differs from the previous three embodiments in that the central portion (904) of the edge portion (901) of the insulating plate (9A) is
Leaving the other parts, namely the upper (902) and lower (903)
It is the point that cut out. Thus, in the central portion (904), the leg portion (403) of the arc extinguishing plate (401) is covered by the insulating plate (9A) so as not to come into contact with the arc (A), and the notched upper portion (902) and lower portion (902). (903) will be exposed to the arc (A). Then, even if the arc (A) flies to the leg (403) at the upper part (902) and the lower part (903), the arc (A) at the central part (904) becomes an insulating plate (9).
Since it cannot be contacted with the leg (403) by being blocked by A), it must pass through the space above or near the central portion (904) of the insulating plate (9A), and the arc (A) The central part is extended and easily driven toward the back of the arc extinguishing device (4). In the embodiment of FIGS. 4 to 6, the insulating plate (9
The inner part on the side opposite to the open / close contacts (2) and (3) of (A) entirely covers the inner part of the leg (403) of the arc-extinguishing plate (401), and thus In the inner part of the arc plate (401), the effect of preventing the arc (A) from contacting and staying on the leg portion (403) in a short-circuited state is obtained in the embodiment of FIGS. It is similar to the case.

As described above, a part of the edge portion (901) of the insulating plate (9A) is cut out, and the leg part (40
By exposing 3) to the arc (A), the arc (A) causes the arc extinguishing plate (40) between the open / close contacts (2) and (3).
The arc (A) extinguishing ability is enhanced by increasing the arc (A) cooling effect while preventing the short circuit from flying along the leg (403) of 1), and the arc (A) is surely extinguished. In addition, if the insulating plate (9A) is made of a resin material, the amount of decomposed gas generated is reduced only in the notched parts, and the breakage and breakage caused by the generated decomposed gas will be sharp. There is less chance that the breaker case or the breaker case will be destroyed due to the excessive pressure increase.

In the above embodiment, one of the contacts is the fixed contact (3), but both the contacts (2) and (3) are movable. Are similarly applicable. Further, the notch of the insulating plate may be formed by machining, or the notch may be formed into the insulating plate.

[Effect of device]

As described above, according to the present invention, the arc extinguishing ability of the arc extinguishing device can be improved by a very simple structure in which a part of the edge of the insulating plate on the side of the opening / closing contact is cut.

[Brief description of drawings]

1 is a partially cutaway perspective view of an arc extinguishing device for a circuit breaker and a circuit breaker according to an embodiment of the present invention, FIG. 2 is a plan view of FIG. 1, and FIG.
The figure is a cross-sectional view along the line III-III in FIG. 2, FIG. 4, and FIG.
FIG. 6 and FIG. 6 are partial sectional perspective views of different embodiments of an arc extinguishing device for a circuit breaker and a circuit breaker according to the present invention, and FIG. 7 is a partial sectional side view of a circuit breaker and a circuit breaker equipped with a conventional arc extinguishing device. 8 and 9 are plan views of FIG. In the figure, (2) and (3) are opening / closing contacts, (4) is an arc extinguishing device, (401) is an arc extinguishing plate, (403) is a leg of the arc extinguishing plate (401), and (9A) is an insulation. Plate, (901) is the edge of the insulating plate (9A) on the side of the open / close contact, (902) is the upper part of the edge (901), (90
3) is the lower part, (904) is the central part, and (A) is the arc. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (5)

[Scope of utility model registration request] 1. An arc extinguishing device for a circuit or a breaker, which is arranged so as to face a pair of open / close contacts, and which extinguishes an arc generated between the open / close contacts when the current is turned off or turned off. A plurality of substantially U-shaped arc-extinguishing plates that are open to the contact side are held in a stacking relationship at intervals from each other, and insulating plates are provided inside both legs of the arc-extinguishing plate to provide both legs of the arc-extinguishing plate. A part of the insulating plate on the side of the opening / closing contact is notched, and the leg of the arc extinguishing plate is exposed to the arc at the notched part, while the opening / closing contact is made. An arc extinguishing device for a circuit or a breaker, characterized in that the inner part on the side opposite to the above part entirely covers the inner part of the leg of the arc extinguishing plate. 2. The utility model registration as claimed in claim 1, characterized in that the central portion is cut out leaving the upper and lower edge portions of the insulating plate on the side of the opening and closing contacts. Arc device. 3. An extinguishing circuit or breaker according to claim 1, characterized in that the upper part of the edge of the insulating plate on the side of the opening / closing contact is left and the other part is notched. apparatus. 4. An extinguishing circuit or disconnection arc according to claim 1, characterized in that a lower part of an edge of the insulating plate on the side of the opening / closing contact is left and the other part is notched. apparatus. 5. A utility model registration circuit as claimed in claim 1, characterized in that a central portion of an edge portion of the insulating plate on the side of the opening / closing contact is left and other portions are cut away. Arc extinguishing device.