JPS62123625A - Arc extinguisher - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an arc extinguishing device, and more particularly to an arc extinguishing device suitably used in a circuit breaker.

Conventional Art In a circuit breaker that is connected to an electrical circuit and performs opening and closing operations, arcing is unavoidable when the circuit is turned on and off, and an arc extinguishing device has been proposed to reduce and prevent damage to the contacts caused by this. ,It is used.

In the conventional technology, a yoke is provided at the contact part, a conductor is wound around the yoke in a coil shape, and a short circuit current is passed through the coil part, and the resulting magnetic flux drives the arc to move and extinguish it. Ta.

However, with the conventional method, in a circuit breaker with a large power capacity of several hundred A, the cross-sectional area of the coil portion becomes large, making it difficult to wind the coil. In small-capacity circuit breakers, space for forming the coil cannot be obtained due to miniaturization, so a ventilation hole is provided in the circuit breaker case to bring the arc into contact with outside air and cool the arc. A method of extinguishing the arc is used.

Problems to be Solved by the Invention However, with this method, wear of the contacts due to arcing was unavoidable, and the life of the circuit breaker was short. Therefore, there has been a desire for a circuit breaker that has excellent arc-extinguishing action and reduces contact wear due to arcing.

An object of the present invention is to provide an arc extinguishing device for solving the above-mentioned technical problems.

Means for Solving the Problems According to the present invention, in the electric circuit on the fixed contact side of a circuit breaker, a current carrying path is provided below the fixed contact in parallel with a gap therebetween, and the above current carrying path is It is formed in an S-shape, one end of which is integrally connected to the fixed contact, and the other end integrally connected to the power supply terminal member, so that the current direction of the central part of the current carrying path and the fixed contact are the same. This is an arc extinguishing device characterized by being formed as follows.

Function According to the present invention, by arranging the fixed contact and the current flowing in the center of the current-carrying path in the same direction, a strong magnetic driving force is generated against the arc, thereby extinguishing the arc.

Embodiment FIG. 1 is a partially cutaway sectional view showing a contact portion of a circuit breaker according to an embodiment of the present invention. The handle 2 of the circuit breaker 1 is angularly displaced in the direction indicated by the arrow a (to the right in FIG. The movable contact 8 fixed to the contact 7 is separated from the fixed contact 5 and the fixed contact 6 fixed to the fixed contact 5. The fixed contact 5 extends from the terminal member 3 to the right in FIG. 1 and is integrally connected by welding or the like at the end of the S-shaped electrode plate 4 which is integrally formed with the terminal part shrine 3. There is. Recess 1 in terminal portion 9 of circuit breaker 1
A plurality of ventilation holes 12 are bored in a separating plate 11 provided at 0. When the handle 2 is angularly displaced in the direction opposite to the arrow a (to the left in FIG. 1), an internal mechanism (not shown) pushes the movable contact 7 downward in FIG. Crimp contact is made and the circuit is turned on. An arc occurs when these contacts separate from each other.

FIG. 2 is a perspective view showing the structure on the fixed contact side of an embodiment of the present invention. The S-shaped electrode plate 4 is formed by current-carrying paths 4a to 4g, with current-carrying paths 4b and 4f located on the same plane on both sides of the current-carrying path 4d.
Spaces 13a and 13b are formed between the four steps. The fixed contact 5 is connected to the current-carrying path 4g at the end of the S-shaped electrode plate 4.
One end thereof is integrally connected to the current conducting path 4g by welding or the like, and a fixed contact 6 is fixed to the fixed contact 5. Note that a gap 14 is formed between the fixed contact 5 and the current conducting path 4d.

The terminal member 3 and the S-shaped electrode plate 4 form an integral structure on the same plane via a conductive path 4a, and a terminal screw (not shown) through hole 15 is bored near the end of the terminal member 3. There is. Here, in FIG. 2, the electric current flows from the terminal member 3 in the direction indicated by the arrow, and the current-carrying paths 4a to 4g forming the S-shaped electrode plate 4 are shown.
It is assumed that the circuit is interrupted while the liquid is flowing through the fixed contact No. 6 toward the movable contact (not shown) following the directions indicated by the arrows.

FIG. 3 is a sectional view taken along the section line AA in FIG. 2. The operation of this embodiment will be explained with reference to FIGS. 2 and 3.

The direction of the current I in FIG. 2 is as described above, and the direction of the current I in FIG.
In the figure, the direction perpendicular to the page and going from the front to the front of the page is indicated by a black mark, and the direction from the front to the back of the page is indicated by a black mark. In FIG. 3, the movable contact 8 separates from the fixed contact 6, causing an arc 16 between both contacts.
is occurring. At this time, if we pay attention to the direction of the current, since the direction of the current flowing in the current carrying path 4g and the fixed contact 5 is the same, the magnetic flux B follows the right-hand law due to the double current 2g centered around the air gap 14. is generated in the clockwise direction, and on the other hand, the current Ia flowing in the arc 1G is from the bottom to the top in FIG.
A force according to Lemming's left-hand rule is generated in a direction from the front to the back of the page, and this drives the arc 16 to move in the direction of the terminal member 3 in FIG. 2 (from the right to the left in FIG. 2).

Outside air flows into the vicinity of the terminal member 3 through the ventilation hole 12 shown in the first diagram, and the arc 16 is cooled and extinguished.

Note that although the current flowing through the energizing paths 4b and 4f is in the opposite direction to the current flowing through the energizing path 4d and the fixed contact 5, they are separated by spaces 13a and 13I], and the force exerted on the arc 16 is ignored. This is Shiruchino. What should be noted in this embodiment is that the terminal member 3 and the S-shaped electrode plate 4 are integrally formed, making it easy to manufacture the contact. Because of this arrangement, even in a small and small capacity circuit breaker, it is possible to generate a magnetic flux with a strong driving force against the arc, which improves the arc extinguishing ability.
This means that it is possible to realize a circuit breaker.

FIG. 4 is a perspective view showing the structure on the fixed contact side of another embodiment of the present invention. FIG. 4 is similar to FIG. 2, and corresponding parts are provided with the same reference numerals. What should be noted in FIG. 4 is the space 13a on both the left and right sides of the current-carrying path 4d of the S-shaped electrode plate 4,
This is because a U-shaped magnetic yoke 17 is provided that penetrates through the magnetic yoke 13b. The U-shaped magnetic yoke 17 is inserted from below the S-shaped pole plate 4 as shown in FIG.

The fifth section is a sectional view taken along the section line CC in FIG. 4. The U-shaped magnetic yoke 17 increases the magnetic force generated by the current flowing through the energizing path 4d and the fixed contact 5, and the driving force for the arc 16 increases. Also, energized path 4
Since the magnetic flux in the opposite direction due to the currents in b and 4f is shielded, the arc extinguishing ability is improved compared to the previous embodiment.

Furthermore, considering the influence of the above-mentioned energizing paths 4b and '4f, the space 13
Since there is no need to widen a and 13b, the overall shape can be made smaller.

FIG. 6 is a perspective view showing the structure on the fixed contact side of still another embodiment of the present invention. Figure 6 is similar to the above-mentioned Figures 2 and 4.
Similar to the figures, corresponding parts are provided with the same reference numerals. What should be noted in this embodiment is that the fixed contact 5a is further extended in the direction of the terminal member 3 to form the arc travel plate 18.

FIG. 7 is a cross-sectional view taken from the section line DD in FIG. 6. The operation of this embodiment will be explained with reference to FIGS. 6 and 7. In FIG. 7, when the movable contact 8 separates from the fixed contact 6, an arc 16a is generated between both contacts, and as described above, this arc 16a is caused by the magnetic flux generated by the current I and the arc current flow a. 7 According to the lemming left hand rule, a force is applied to the left in Figure 7. If the arc traveling plate 18 were not present, the arc 16a would still exist between the two contacts, but because the arc traveling plate 18 is present, its path is changed from 16a to 161 by being subjected to the above-mentioned force.
→16c, the arc moves sequentially to the left in FIG. 7, and therefore the arc generation location shifts from between the contacts to between the movable contactor 8 and the arc traveling plate 18. As a result, the arc IGa generated between the contacts is extinguished in a short time, damage to the contacts is reduced and prevented, and reliability and length can be improved.

FIG. 8 is a perspective view showing another embodiment of the present invention. 8th
The figures are similar to the previous embodiments and corresponding parts are provided with the same reference numerals. What should be noted in this embodiment is that the fixed contact 5, the S-shaped electrode plates 4 and 18, and the terminal member 3 are punched out from a continuous single plate and bent at the 4°g portion of the current-carrying path. , the fixed contact 5 is formed and the entire structure is completely integrated.

This eliminates the process of connecting the fixed contact 5 and the current-carrying path 4g by means such as welding, improving productivity such as reducing the number of parts and ease of assembly, and reducing costs.
Also, reliability is further improved.

Effects As described above, according to the present invention, the fixed contact and the current-carrying path are arranged in parallel with an air gap in between, and the current direction is the same, so that a strong driving force against the generated arc is produced. This makes it possible to realize an arc extinguishing device with a simple structure that does not require a special arc extinguishing coil unlike the prior art.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway sectional view of a circuit breaker according to an embodiment of the present invention, Fig. 2 is a perspective view showing the structure on the fixed contact side, Fig. 3 is a sectional view, and Fig. 4 is a cross-sectional view of the circuit breaker according to the present invention. FIG. 5 is a sectional view thereof, FIG. 6 is a perspective view of still another embodiment, FIG. 7 is a sectional view thereof, and FIG. 8 is a sectional view of another embodiment. FIG. 3... Terminal member, 4... S-shaped electrode plate, 4a to 4g.
... Current carrying path, 5 ... Fixed contact, 6 ... Fixed contact,
14...Gap, 16...Arc, 17...U-shaped magnetic yoke, 18...Arc running plate, ■...Circuit current agent Patent attorney Number of strokes Keiichi Figure 1 Figure 2 Figure 3 Figure 5 Figure 6

Claims (1)

[Scope of Claims] In the electric path on the fixed contact side of the circuit breaker, a current conducting path is arranged in parallel with a gap between the lower part of the fixed contact, and the current conducting path is formed in an S-shape, One end thereof is integrally connected to the fixed contact, and the other end is integrally connected to the power supply terminal member, and is formed so that the current direction of the central part of the current carrying path and the fixed contact are the same direction. An arc extinguishing device characterized by: