JPH0327320Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field of the invention] The present invention is an arc extinguishing method for a circuit breaker or breaker for extinguishing an arc generated between contacts when the circuit breaker or breaker performs a rupture operation. Regarding the equipment, especially in the arc extinguishing chamber, grid plates are arranged radially in the vertical direction,
This invention relates to improvements in arc extinguishing devices for circuits and breakers that attract arcs into the gaps.

[Technical background of the invention]

A circuit breaker generates an arc between the contacts of the fixed electrode and the movable electrode when the current is interrupted. As one method for extinguishing this arc, there has conventionally been an arc extinguishing device constructed as shown in FIGS. 1 and 2. That is, an arc extinguishing chamber 1 is provided as a component of the circuit and disconnector, and a contact 2a of a fixed electrode 2 and a contact 3a of a movable electrode 3 are arranged inside the arc extinguishing chamber 1.
Further, in the arc extinguishing chamber 1, U-shaped grid plates 4 are arranged radially in the vertical direction, and the contacts 2a and 3a are located in the recesses of the grid plates 4. The grid plate 4 is supported on its side by an insulating grid support plate 5. Further, in the arc extinguishing chamber 1, a rear plate 6 is attached to the inner surface of the side wall located on the side where the grid plate 4 is arranged when viewed from the contacts 2a and 3a, and an exhaust hole 7 is installed above the same wall. is drilled.

The conventional arc extinguishing device having the above structure attracts the arc generated between the contacts 2a and 3a during the cutting operation into the gap between the grid plates 4. The attracted arc forms an arc column between the grid plates 4, is driven in a direction away from the contacts 2a and 3a, and is gradually extinguished. Further, the arc gas generated during the above-mentioned cutting-off passes through the gap of the grid plate 4,
The air passes through the space A between the end of the grid plate 4 and the rear plate 5 and is discharged from the exhaust hole 7 located above the space A.

[Problems with background technology]

The conventional device having the above configuration had the following problems. That is, since the space A between the end of the grid plate 4 and the rear plate 5, which is the discharge path for the arc gas generated during the shrinking, is narrow, the arc gas cannot be discharged quickly. As a result, the arc gas flows in the direction of the hole 9 through which the movable electrode 3 is inserted.
The arc is prevented from being driven into the gap between the grid plates 4, which may adversely affect the insulation recovery after the shingle breaks, and furthermore, there is a risk that the pressure inside the circuit or disconnector will increase, leading to damage to the molded case 8. It was hot. Also,
Since the leg portions of the grid plate 4 located on both sides of the contacts 2a and 3a are located away from the discharge path, it is difficult to efficiently drive the arc attracted to the leg portions. Therefore, the leg portions of the grid plate 4 located on both sides of the contacts 2a and 3a hinder the extinguishing of the arc and have an adverse effect on the insulation recovery after the breakage.

[Purpose of invention]

The purpose of the present invention is to eliminate the above-mentioned problems, quickly extinguish the arc that occurs between the contacts when the current dies out, and recover the insulation, and also quickly remove the arc gas generated when the current dies out from the exhaust hole. It is an object of the present invention to provide an arc extinguishing device for a circuit or breaker which can be discharged and prevent damage due to gas expansion pressure.

[Summary of the idea]

The present invention consists of an arc extinguishing chamber that has a box shape with first to fourth side walls and has an exhaust hole upwardly communicating with the outside air, and a fixed electrode contact disposed inside the arc extinguishing chamber and a contact point connected to the contact point. A contact portion having a contact point of a movable electrode to be separated; and a contact portion provided between the contact portion and the first side wall of the arc extinguishing chamber, and arranged radially at intervals in the vertical direction so as to face the contact portion. A plurality of grid plates provided, a grid support plate supporting the plurality of grid plates provided on the inner surfaces of the second and third side walls of the arc extinguishing chamber located on both sides of the contact portion and the grid plates, and a contact point. The arc-resistant electrodes are respectively disposed between the arc-extinguishing chamber and the second and third side walls of the arc-extinguishing chamber, one end of which is supported by the grid plate, and the other end of which is supported by the fourth side wall of the arc-extinguishing chamber. and an insulating plate having a plurality of grid plates and a first insulating plate of the arc extinguishing chamber.
A first space is formed between the insulating plate and the side wall of the arc extinguishing chamber, and second and third spaces are formed between the insulating plate and the second and third side walls of the arc extinguishing chamber. The space is configured as an exhaust passage for arc gas generated when the contact portions are opened and discharged through between the plurality of grid plates.

As a result, the arc does not move to both sides of the contact section partitioned by the insulating plate, but moves to the grid plate side and efficiently moves between them, extinguishing the arc, and the arc gas flows into the first to third spaces. Furthermore, since the portion of the grid plate close to the contact portion is reduced, the generation of metal ions due to melting is reduced.

[Example of idea]

FIGS. 3 and 4 are diagrams showing the configuration of an embodiment of the present invention. In the figure, 1 is the arc extinguishing chamber of the circuit and disconnector, and inside it is the contact 2 of the fixed electrode 2.
A contact portion having a contact point 3a of the movable electrode 3 is arranged. A rear plate 6 is attached to the inner surface of the first side wall 1a of the arc extinguishing chamber 1 facing the contact portion, and the second and third side walls 1b of the arc extinguishing chamber 1 located on both sides of the contact portion , 1c have grid support plates 5, 5 attached to their inner surfaces, and an exhaust hole 7 is provided above the rear plate 6.

In addition, the arc extinguishing chamber 1 includes a contact portion and a first side wall 1a.
A plurality of grit plates 10 are disposed radially in the vertical direction at regular intervals between the two and facing the contact portions. This arrangement is maintained by having both ends of the grid plate 10 supported by the grid support plate 5. Note that a space A is secured between the end of the grid plate 10 on the side opposite to the contact portion and the rear plate 6. Further, arc-resistant insulating plates 11 are provided on both sides of the contact section in parallel with the grid support plate 5, one end of which is supported by the grid support plate 10, and the other end of which is supported by the arc extinguishing chamber. 1 and supported by a fourth side wall 1d opposite to the first side wall 1a. With this insulating plate 11, an insulating plate 11 and an arc extinguishing chamber 1 are provided on both sides of the contact part.
Spaces B and C are secured between the second and third side walls 1b and 1c.

Next, the overall operation of the circuit and breaker equipped with the above-mentioned arc extinguishing device will be briefly described as follows. That is, the handle 12 and opening/closing mechanism 13 shown in FIG.
Since the movable electrode 3 and the movable electrode 3 are engaged with each other, when the handle 12 is operated, the opening/closing mechanism 13 is interlocked to open and close the movable electrode 3. Further, when a large current such as a short circuit current flows through the circuit or disconnector, the opening/closing mechanism is automatically operated by a detection device not shown in the figure, and the movable electrode is opened. When the circuit or disconnector performs the cutting operation in this manner, an arc is generated between the contact 2a of the fixed electrode 2 and the contact 3a of the movable electrode 3. Further, when the above-mentioned arc occurs, arc gas is generated accordingly.

According to this embodiment configured in this way, the arc is quickly attracted to the grid plate 10 and extinguished, and the arc gas is quickly discharged from the exhaust hole 7, as described below. That is, first, the function of discharging arc gas will be explained. The arc gas generated as described above passes through the gaps between the grid plates 10 and reaches the space A. Then, it advances upward in the space A and is discharged from the exhaust hole 7. On the other hand, a part of the arc gas is folded back in the gap between the grid plates 10 and escapes into the spaces B and C, after which it advances upward through the spaces B and C and is discharged from the exhaust hole 7. In this embodiment, as mentioned above, spaces B and C, which are partitioned by an insulating plate 11 and serve as exhaust passages, are added to the empty space by removing the leg portions of the conventional grid plate 4, thereby creating a total of three exhaust passages. Therefore, the arc gas generated during the shrunken operation can be promptly discharged from the exhaust hole 7, and damage to the mold case 8 due to the gas expansion pressure is prevented.

Next, the action of extinguishing an arc will be explained. As mentioned above, the contact 2a of the fixed electrode 2 and the contact 3 of the movable electrode 3
The arc generated between the contact point 2a and the grid plate 10 is attracted to the grid plate 10 by the action of the magnetic field generated around it, and the arc generated between the contact point 2a and the grid plate 10, the gap between the grid plate 10, and the contact point between the grid plate 10 and the contact point 2a. 3
A is connected to form a U-shaped arc column. In this embodiment, there is no grid plate 10 on the sides of the contacts 2a and 3a, and an arc-resistant insulating plate 1
1 is provided, the above-mentioned arc attraction action is performed only on the side of the grid plate 10 opposite to the contact point. Therefore, the arc column is efficiently driven toward the side opposite to the contact point where the width of the gap in the grid plate 10 is widened by the pressure of the arc gas mentioned above. Then, the arc column increases in length and quickly extinguishes.

In this embodiment, the arc is connected to the grid plate 10 as described above.
Since the structure is such that it is easy to attract and drive toward the side opposite to the contact point where the width of the contact point is widened, the arc generated at the time of the shrinkage can be quickly extinguished and the insulation can be recovered. By the way, this embodiment has the following effects in addition to the above-mentioned effects. That is, the grid plate 10 is placed on the side of the contacts 2a and 3a.
Since there is no contact point 2a and 3a, the portion of the grit plate 10 near the contacts 2a and 3a is reduced compared to the prior art, and therefore the contact point 2a and 3a
The generation of metal ions due to melting of the grid plate in the vicinity of the grid plate is reduced, and insulation recovery performance is improved.

Note that the present invention is not limited to the one embodiment described above. For example, in the above-mentioned embodiment, the exhaust hole 7 in the arc extinguishing chamber 1 was explained as a circuit breaker and a circuit breaker in which the exhaust hole 7 was bored above the rear plate 6, but the present invention is limited to the position of the exhaust hole 7. It is not something that is done, but
It may be a circuit or a disconnector drilled in the upper side of the arc extinguishing chamber 1.

[Effect of idea]

According to the arc extinguishing device for circuit breakers and circuit breakers of the present invention, the grid plate on the side of the contact part is eliminated, an arc-resistant insulating plate is provided here, and the second and third exhaust passages are added. , the arc gas can be quickly discharged through the gap between the grid plates, and the arc is efficiently drawn between the grid plates by the high-pressure arc gas squeezed by these insulating plates and quickly extinguished. Since there are no grid plates near the sides, the generation of metal ions due to melting of the grid plates is reduced, which has the effect of improving insulation recovery performance.

[Brief explanation of drawings]

Figures 1 and 2 are diagrams showing the configuration of a conventional circuit breaker. Figure 1 is a cross-sectional front view, Figure 2 is a cross-sectional plan view, and Figures 3 and 4 are diagrams of the present invention. FIG. 3 is a cross-sectional front view, and FIG. 4 is a cross-sectional plan view. 1 ... arc extinguishing chamber, 2... fixed electrode, 2a... contact, 3... movable electrode, 3a... contact, 4... grid plate, 5... grid support plate, 6... rear plate,
7...Exhaust hole, 8...Mold case, 9...
Hole, 10...Grid plate, 11...Insulating plate, 12
...Handle, 13...Opening/closing mechanism.

Claims (1)

[Scope of utility model registration request] an arc extinguishing chamber having a box shape having first to fourth side walls and having an exhaust hole upwardly communicating with outside air;
a contact portion disposed within the arc extinguishing chamber and having a contact of a fixed electrode and a contact of a movable electrode that comes into contact with and separates from the contact; and a contact portion provided between the contact portion and the first side wall of the arc extinguishing chamber; a plurality of grid plates disposed radially at intervals in the vertical direction so as to face the contact portion; and second and third side walls of the arc extinguishing chamber located on both sides of the contact portion and the grid plates; Grid support plates are respectively provided on the inner surfaces of the grid plates and support the plurality of grid plates, and each of the grid support plates is disposed between the contact portion and the second and third side walls of the arc extinguishing chamber, and one end thereof is connected to the grid plate. an arc-resistant insulating plate supported by a plate and whose other end is supported by a fourth side wall of the arc extinguishing chamber, the plurality of grid plates and the first side wall of the arc extinguishing chamber; and a second space is formed between the insulating plate and the second and third side walls of the arc extinguishing chamber.
and a third space, and these first to third spaces are configured as exhaust passages for arc gas generated when the contact portions are opened and discharged through between the plurality of grid plates. Arc extinguishing device for circuit breakers and circuit breakers.