JPS5911385Y2 - Vacuum shield electrode - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a breaker electrode structure for a vacuum breaker, and more particularly to an electrode structure in which the arc running length is increased relative to the electrode diameter.

Conventional electrode structures for cutting off large currents include, as shown in FIG. As shown in the figure, a spiral electrode 3 that applies a magnetic field in the direction of a lateral force to the arc to drive it outward, and a screw electric tow (not shown) in which the groove is inclined in the axial direction are known.

Also, although not shown, if a vertical magnetic field is applied, then the magnetic field causes an arc? Confining longitudinal magnetic field electrodes are known.

4 is a reed, and 5 is an arc pedal.

The above-mentioned butt electrode moves the arc linearly from the center in the circumferential direction using electromagnetic force and diffusion force, and the breaking current value is proportional to the electrode diameter when the electrode material (for example, Cu) is the same. , there is the following relational expression.

α ■B=k-D ・・・・・・・・・(1) Here, ■B
is the maximum breaking current value (KA), D is the electrode diameter (mm), K
and α are constants, and for copper electrodes K-1, α = 0
．． It is 64.

On the other hand, the spiral electrode shown in FIG. 2 extends the arc traveling length by an arc pedal 5 partitioned by a groove cut into a spiral shape, and the maximum breaking current value ■8 is I5=P·■8... ...(2), which increases by a constant P times compared to a butt electrode of the same diameter.

For example, when eight spiral electrodes are used as a pedal, this P becomes P=π/2.

The present invention has an electrode structure in which a single ring is provided in the arc running direction (radial direction of the electrode) of the spiral electrode, so that the arc rotational driving force and arc running length are large with an electrode of the same diameter, and the breaking current performance is improved. The purpose is to provide an improved electrode structure.

FIG. 3 shows an embodiment of the present invention, in which it is applied to a spiral electrode.

In the figure, a copper ring 7 is provided on the arc pedal 5 of the spiral electrode 6 and is concentric with the center contact 1 and lower than the upper surface of the center contact 1.

In this case, as shown in the enlarged view of the main part in Fig. 4, when the arc reaches point P on the ring 7, the arc current I is shunted to the adjacent pedal by the ring 7, so that the arc The outward force of is weakened and the arc temporarily stops on the ring 7, but from I>IR=I5 the arc runs on the remaining pedals (dashed line).

Also, if IR and I5 are significantly different, do you run on the ring and eventually run the rest of the pedal outward? (dotted chain line).

That is, since the pedal apparently moves in the same way as if it had been lengthened, the arc traveling length is substantially increased and the breaking performance is improved.

Note that the number of rings 7 is not limited to one, but a plurality of rings may be provided to further increase the arc traveling length, and the same effect can be obtained even if the rings 7 are eccentrically arranged as shown in FIG.

In this case, the relative position of the ring provided on the counter electrode is also adjusted with respect to the eccentric ring.

As described above, since the electrode according to the present invention connects the surfaces of the center contact side of each arc pedal with each other with a ring, it fully utilizes the characteristics of the spiral electrode that has a large arc rotational driving force, and the arc is When reaching point P, arc current I flows to the adjacent pedals at ring 7 ■8・■5
Since the arc pedal of the spiral electrode is longer, the arc travel length can be increased with the same electrode diameter, or in other words, the electrode diameter can be reduced with the same travel length, and the breaker It is possible to improve the performance or downsize the device.

On the other hand, since each arc pedal of the spiral electrode is connected by a ring, there are effects such as improved mechanical strength and increased durability.

[Brief explanation of the drawing]

Figure 1 is a side sectional view a and a plan view b showing a conventional butt electrode.
, Fig. 2 is a side sectional view a and a plan view b showing a conventional spiral electrode, Fig. 3 is a side sectional view a and a plan view b showing an embodiment of the spiral electrode of the present invention, and Fig. 4 is a side sectional view a and a plan view b showing a conventional spiral electrode. FIG. 5 is an enlarged view of a main part for explaining arc travel, and is a diagram showing another embodiment of the present invention. 1... Central contactor, 5... Arc pedal, 6...
Spiral electrode, 7...ring.

Claims (1)

[Scope of utility model registration request] A plurality of arc pedals for rotationally driving an arc are provided around a central contact, and a space is provided between each arc pedal, such that the surface of each arc pedal on the side of the central contact is connected to each other, A vacuum breaker electrode characterized by having a ring.