JPH06196080A - Arc extinguishing device - Google Patents

Abstract

PURPOSE:To provide an arc extinguishing device capable of improving the flow of arc gas to improve current limiting performance. CONSTITUTION:In an insulating body 5 formed into a substantially U-shape with both side parts 6, 6 having a determined area and a connecting part 7, to which a movable contact 3 is advanced from one opening part 5a to fixed and movable contacts 2, 4 are situated near the longitudinal middle, the opening area of one opening part 5a is made smaller than the area of the other opening part 5b and the sectional area near the middle. In a one having a reflux passage 13 between both side parts 6,6 of the insulating body 5 and the wall surface 12 of a case 11, a diameter extending part 5f extending outward is formed on the edge of one opening part 5a of the insulating body 5.

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 suitable for circuit breakers and the like.

[0002]

2. Description of the Related Art As this type of arc extinguishing device, there is one having a structure shown in FIG. 8 (for example, Japanese Patent Laid-Open No. 01-206522). In the figure, 1 is a fixed contact provided with a fixed contact 2, 3 is a movable contact provided with a movable contact 4 that contacts and separates from the fixed contact 2, and 5 is provided on both side parts 6 and 6 having a predetermined area and a connecting part 7. Is a substantially U-shaped insulator. The insulator 5 is made of plastic, and the movable contact 3 is inserted through one opening 5a so that both contacts 2 and 4 are located near the middle in the longitudinal direction. Reference numeral 9 is a substantially U-shaped magnetic material arranged around the insulator, 10 is a substantially semi-circular conductor through which the electric current of the electric path flows, and these are insulators for the arc generated between both contacts 2 and 4. A magnetic drive member 8 that is magnetically driven to the other opening 5b side is configured.
The conductor 10 is integrally formed with the fixed contactor 1, and may be referred to as a drive coil because of its shape and function.

Such an arc extinguishing device is arranged at a position communicating with a gas discharge passage such as a circuit breaker. Then, when an excessive current flows in the circuit and the contacts should be opened, the contacts are opened due to the electromagnetic repulsive force generated by the currents of the fixed contact 1 and the movable contact 3, for example. The arc generated at is magnetically driven by the magnetic body 9 and the conductor 10, and as a result, the arc extends and the arc voltage rises. Further, arc gas is generated from the insulator 5 by thermal decomposition due to the heat of the arc, and the arc gas is discharged to the outside through the gas discharge passage so that the pressure of the arc gas promotes the extension of the arc.

FIG. 10 shows the pressure of the arc gas described above.
In order to use (flow) efficiently, both sides of insulator 5
The arc gas recirculation path 13 formed between the wall surfaces 12 of the cases 6 and 6 is provided. In this case, a part of the arc gas discharged to the outside through the gas discharge passage 14 is passed through the return passage 13 to promote the extension of the arc again.

As described above, the arc-extinguishing device of this type performs the current limiting arc extinction by utilizing the magnetic driving force and the pressure of the arc gas.

[0006]

However, in the former arc extinguishing device described above, the arc gas does not flow only in the direction that promotes the extension of the arc, and as shown in FIG. It also flows in the direction of doing. In the figure, arrow F1 indicates the flow of arc gas in the direction of promoting the extension of the arc, and arrow F2 indicates the flow of arc gas in the direction of inhibiting the extension of the arc. This arc gas flow F2 is
The current limiting performance is reduced accordingly.

The latter arc extinguishing device described above is
The arc gas flows F3 into the reflux path 13 and the arc gas flows into the opening 5a of the insulator 5, but it is difficult to properly flow the arc gas.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an arc extinguishing device capable of improving the current limiting performance by improving the flow of arc gas.

[0009]

In order to solve the above-mentioned problems, an arc-extinguishing device according to a first aspect of the present invention is a movable contact having a fixed contact provided with a fixed contact and a movable contact brought into contact with and separated from the fixed contact. A child, an insulator into which the movable contact enters from one opening so that the contacts are located near the middle in the longitudinal direction without being U-shaped at both sides and the connecting part having a predetermined area, and between the contacts In an arc extinguishing device having a magnetic drive member that magnetically drives the arc generated in the other opening side of the insulator, the opening area of one opening of the insulator is It is configured to be smaller than the cross-sectional area.

The arc-extinguishing device according to a second aspect of the present invention includes a fixed contact provided with a fixed contact, a movable contact provided with a movable contact that comes in contact with and separated from the fixed contact, both side portions having a predetermined area, and a connecting portion. In the insulator in which the movable contact enters from one opening so that both contacts are located near the middle in the longitudinal direction and in the middle of the longitudinal direction, and the arc generated between both contacts is opened in the other opening of the insulator. A magnetic drive member that magnetically drives to the side, in an arc extinguishing device having a return path for arc gas formed between both sides of the insulator and the wall surface of the case, at the edge of one opening of the insulator, It has a configuration in which a diameter-expanded portion that expands outward is formed.

According to a third aspect of the arc-extinguishing device, the magnetic drive member according to the first or second aspect is provided with a substantially U-shaped magnetic body arranged around an insulator and a side plate of the insulator. It is composed of a substantially semi-circular electric conductor which is arranged outside and through which a current in an electric circuit flows.

[0012]

According to the first aspect of the invention, the arc gas is less likely to flow in a direction that hinders the arc extension, that is, toward one opening of the insulator, and the arc extension can be further promoted to limit the current. Performance is improved.

Further, according to the second aspect of the invention, the arc gas passing through the recirculation passage can easily flow from one of the openings of the insulator, the extension of the arc can be further promoted, and the current limiting performance can be improved.

Further, according to the third aspect of the invention, the magnetic driving force of the magnetic body and the conductor is enhanced, and therefore the action of the first or second aspect is further enhanced and the current limiting performance is further improved. .

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. In addition, the same code | symbol is attached | subjected to the member with the same basic function as the conventional thing.

Reference numeral 1 denotes a fixed contact, which is integrally formed of a conductive plate material including a conductor to be described later. The base 1a is a contact fixing part that is cantilevered at the end and has a slightly narrow width.
1b, and semicircular conductors 10 and 10 on both sides of the contact fixing part 1b.
Is provided. Reference numeral 2 denotes a fixed contact, which is fixed to the contact fixing portion 1b at a position where it is sandwiched between the conductors 10 and 10. As a result, in the fixed contact 1, the conductor 10 → contact fixing part
An electric current flows through the route of 1b → fixed contact 2. A movable contact 3 is supported and driven by a general contact opening / closing mechanism (not shown), and has a movable contact 4 fixed to the fixed contact 2 at its tip end.

Reference numeral 5 denotes an insulator, which is made of plastic and is molded in a substantially U-shape by the side portions 6, 6 having a predetermined area and the connecting portion 7. On the outer surface of the insulator 5, supporting collars 5c and 5d and ribs 5e for division are provided in order to dispose a magnetic drive member described later. This insulator 5 has two contacts 2,
4 is positioned so as to cover the base portion 1a of the fixed contactor 1 so that the movable contactor is provided from one opening 5a.
3 enters. In addition, the conductor 10 is a support collar.
It is located in the range defined by 5c and the rib 5e for division.

What is important in this insulator 5 is that the opening area of one opening 5a is smaller than the opening area of the other opening 5b and the cross-sectional area near the middle. In this embodiment, as shown in FIG. 3, the inner width of both side portions 6, 6 and the opening width L1 of the other opening portion 5b are 7 mm, and one opening portion is
The opening width L2 of 5a is 5 mm. That is, a protrusion protruding inward is formed on the inner surface of the opening 5a.

Reference numeral 8 is a magnetic drive member, which is composed of a magnetic body 9 and a conductor 10. The magnetic body 9 is made up of
The a and 9a and the connecting piece 9b are formed in a substantially U shape and are arranged around the insulator 5. The facing pieces 9a, 9a are partly cut off so that the tip end surfaces thereof come into contact with the partitioning ribs 5e. conductor
As described above, the reference numeral 10 is integrally formed with the fixed contact 1, and is located in the range formed by the supporting collar 5c and the partitioning rib 5e. Since the conductor 10 has a semicircular shape, it may be referred to as a drive coil.

FIG. 4 shows a circuit breaker in which such an arc extinguishing device is incorporated. The arc extinguishing device is arranged at a position communicating with the gas discharge passage 14 of the case 11 forming the outer shell of the circuit breaker. . Specifically, the insulator on the side near the exhaust port 15 on the power supply side
The other opening 5b of 5 is located. Reference numeral 16 is an exhaust port on the load side.

Such an arc-extinguishing device opens the contacts when an excessive current flows in the circuit to open the contacts, for example, by electromagnetic repulsive force generated by the currents of the fixed contact 1 and the movable contact 3. The arc generated between both contacts 2 and 4 is magnetic
9 and the conductor 10 magnetically drive, and as a result, the arc extends and the arc voltage rises. Further, arc gas is generated by thermal decomposition from the insulator 5 due to the heat of the arc, and this gas is discharged to the outside through the gas discharge passage 14 and the exhaust port 15 on the power supply side so that the pressure promotes the expansion of the arc. .

In this case, since the opening area of one opening 5a of the insulator 5 is smaller than that of the conventional arc gas, the flow of the arc gas in that direction, that is, the flow F2 in the direction of hindering the extension of the arc F2. Therefore, the flow in the direction of the other opening 5b, that is, the flow F1 in the direction that promotes the extension of the arc, increases, which can further enhance the extension of the arc and improve the current limiting performance.

The inventors of the present application actually measured the passing energy and the maximum arc voltage of the present invention and the conventional one as a substitute value of the current limiting performance. Here, the passing energy is obtained by time-integrating the square of the instantaneous value of the current flowing in the electric circuit at the time of short-circuit interruption, and therefore, the smaller this value is, the more it is given to the load equipment connected to the electric path. Thermal damage can be reduced. The test condition is voltage 265
When the voltage is V and the current is 22 kA, the passing energy is 879.
The maximum arc voltage was 4,000 [AAS] (934000 [AAS] for the conventional product) and 446 [V] (433 [V] for the conventional product).

Next, a second embodiment of the present invention will be described with reference to FIGS. This is different from the first embodiment in that it has an insulator shape and a return path.
Other than that, it is substantially the same.

In order to efficiently use the pressure (flow) of the arc gas, the recirculation path 13 is provided on both sides 6 and 6 of the insulator 5 (more specifically, the facing pieces 9a and 9a of the magnetic body 9) and the case 11. It is formed with a predetermined gap between it and the wall surface 12. The insulator 5 has a diameter-increased portion 5f that expands toward the outside at the rim of the one opening 5a. In this embodiment, as shown in FIG. 7, the inner width of both side portions 6 and 6 and the opening width L1 of the other opening 5b are 7 mm, and the opening width L3 of the end of one opening 5a is 9 mm, and The inclination angle θ when viewed two-dimensionally was about 30 °.

The arc extinguishing device performs substantially the same operation as that of the first embodiment when an excessive current flows in the electric path to open the contacts, and the arc gas flows through the return path 13 and the flow F3 flows through the insulator 5. Good flow into one opening 5a. Therefore, in this case as well, the arc gas has less flow in the direction that obstructs the extension of the arc as compared with the conventional one, and therefore the flow in the direction of the other opening 5b, that is, the flow in the direction that promotes the extension of the arc. The amount of F1 increases, which can further promote the extension of the arc and improve the current limiting performance.

As in the case of the first embodiment, the inventors of the present application actually measured the passing energy and the maximum arc voltage of the present invention and the conventional one as substitute values for the current limiting performance. As a result, the passing energy is 829000 [AAS] (conventional product is 934000 [AAS]) and the maximum arc voltage is 440.
[V] (433 [V] for the conventional product). The peak value of the passing current was 16350 [A] (17027 [A] for the conventional product).

In both embodiments, the magnetic drive member 8 is
Although the magnetic substance 9 and the electric conductor 10 are used for the description, one of them may be omitted if a slight decrease in performance is allowed. Further, although the conductor 10 has been described as being integrally formed with the fixed contact 1, the conductor 10 may be separately formed and electrically connected.

[0029]

In the arc-extinguishing device according to the first aspect of the present invention, it becomes difficult for the arc gas to flow in a direction that impedes the extension of the arc, that is, toward one opening of the insulator, and the extension of the arc can be further promoted. The current limiting performance is improved.

Further, in the arc-extinguishing device according to the second aspect, the arc gas passing through the recirculation path can easily flow from one of the openings of the insulator, which can further promote the extension of the arc and improve the current limiting performance.

Further, in the arc-extinguishing device according to the third aspect, the magnetic driving force of the magnetic body and the conductor is enhanced, and therefore the action according to the first or second aspect is further enhanced and the current limiting performance is further improved. .

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of the present invention.

FIG. 2 is a perspective view of the one excluding the movable contactor and the magnetic body.

FIG. 3 is an explanatory diagram of a flow of the arc gas.

FIG. 4 is a side view in which a part of a circuit breaker incorporating the arc extinguishing device is cut away.

FIG. 5 is an exploded perspective view of essential parts showing a second embodiment of the present invention.

FIG. 6 is a perspective view of the device without the movable contactor and the magnetic body.

FIG. 7 is an explanatory diagram of the flow of the arc gas.

FIG. 8 is an exploded perspective view showing a conventional example.

FIG. 9 is an explanatory diagram of the flow of the arc gas.

FIG. 10 is a plan view of another conventional example.

[Explanation of symbols]

 1 Fixed contact 2 Fixed contact 3 Moving contact 4 Fixed contact 5 Insulator 5a One opening of insulator 5b The other opening of insulator 5f Expanding part of one opening of insulator 6 Both sides of insulator Part 7 Insulator connection part 8 Magnetic drive member 9 Magnetic body that constitutes the magnetic drive member 10 Conductor that constitutes the magnetic drive member 11 Case such as circuit breaker 12 Case wall surface 13 Reflux path

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[Procedure amendment]

[Submission date] August 25, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 7

[Correction method] Change

[Correction content]

[Figure 7]

Claims (3)

[Claims] 1. A fixed contact provided with a fixed contact, a movable contact provided with a movable contact that comes into contact with and separated from the fixed contact, both sides having a predetermined area and a connecting portion are substantially U-shaped, and are not in a longitudinal direction. Has an insulator into which the movable contact enters from one opening so that both contacts are located near the middle of the, and a magnetic drive member that magnetically drives the arc generated between both contacts to the other opening side of the insulator. The arc-extinguishing device, wherein the opening area of one opening of the insulator is smaller than the opening area of the other opening and the cross-sectional area near the middle. 2. A fixed contact provided with a fixed contact, a movable contact provided with a movable contact that comes into contact with and separated from the fixed contact, both sides having a predetermined area and a connecting portion are substantially U-shaped and are not in a longitudinal direction. An insulator into which the movable contact enters from one opening so that both contacts are located near the middle of the, and a magnetic drive member that magnetically drives the arc generated between both contacts to the other opening side of the insulator, In an arc extinguishing device having a return path for arc gas formed between both sides of an insulator and a wall surface of a case, a diameter-expanding portion that expands outwardly at the rim of one opening of the insulator. Arc-extinguishing device. 3. The magnetic drive member is arranged in a substantially U-shape around the insulator, and is disposed outside the side plate of the insulator, and is in a substantially semicircular shape in which a current in an electric path flows. The arc-extinguishing device according to claim 1 or 2, wherein