JPS61153912A - Breaker - 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 Industrial Application] The present invention relates to a circuit breaker, and particularly to the structure of an arc electrode such as a vacuum circuit breaker.

[Conventional technology]

A conventional vacuum cutter will be explained by taking as an example the one shown in JP-A-55-30174 and referring to FIGS. 7 and 8. FIG. 7 shows the electrode of the vacuum cutter. A front view is shown, and FIG. 8 is a cross-sectional view taken along the line ■-■ in FIG. (2a) to (2
d) is an electrode pedal in which an arc electrode (1) is defined as an arc transition portion by four spiral slits (3a) to (3d). The other arc electrode (not shown) is the L electrode (D slits (3a) to (3d)
They are arranged symmetrically to face each other, and these both function as a circuit breaker by bringing the contact/separation surfaces (1a) into contact with/separate from each other.

Next, to explain the electromagnetic effect during operation of the arc electrode (1), when the arc electrode (1) opens, an arc is generated at point P of the contact/separation part (la), and this electrode (1)
A current path is formed between the electrode and the other electrode based on the arc.

Since the current path has a small driving component in the radial direction of the electrode (1), the magnetic field based on the current applies electromagnetic force to further drive the arc in the radial direction.

Moreover, since the electrode pedal (2a) is formed in a spiral shape as shown in Fig. 7, the arc biased in the radial direction of the electrode (1) stops at point P on the electrode pedal (2a). Because it moves by drawing a spiral trajectory Q,
The invention is designed to avoid localized heat input to the electrode (1) due to the arc and improve the cutting performance of the electrode (1). However, with the arc electrode (1), depending on the state of arc generation, the arc expands its diameter and the current density becomes insufficient, making it impossible to obtain sufficient magnetic driving force.
Alternatively, sufficient magnetic driving force may not be obtained due to the influence of external magnetic fields caused by other conductors constituting the breaker. In some cases, it becomes difficult for the arc to migrate, and in the worst case, the arc stagnates at the point where the arc occurs, locally heating that area, which impairs the breaker function.

The present invention was made to solve this problem, and by increasing the magnetic driving force acting on the arc, it is possible to reliably drive and break the arc under any circumstances. ◆The purpose is to provide a disconnection device.

[Means for solving problems]

In the present invention, a plurality of slits are formed in either one of a pair of arc electrodes of a breaker to form electrode pedals that restrict the transition of the arc to the outer edge of the electrode, and the back side of these electrode pedals is provided with a plurality of slits. The arc electrode is constructed by coating a magnetic material.

[Effect]

According to the present invention, the arc generated at the contact/separation portion of the electrode is biased by the magnetic driving force of the magnetic body toward the outer periphery of the electrode pedal to prevent the arc from stagnation, and is reliable as a circuit breaker. It is possible to obtain cutting performance.

〔Example〕

Hereinafter, the present invention will be explained based on the embodiments shown in FIGS. 1 to 7 and 6, with the same or corresponding parts as those in the prior art being designated by the same reference numerals. Figure 1 is a diagram equivalent to Figure 7, and Figure 2 is an I in Figure 1.
I-II II sectional view, in the figure (4a) to (4
d) shows each electrode pedal (2) in the same electrode (1) as before.
a) to (2d) are magnetic bodies attached to the back side, and these magnetic bodies (4a) to (4d) have approximately the same shape as each electrode pedal (2a) to (2d) as shown in Fig. 4. It is formed as a plate with a However, when an arc occurs at the contact/detachment surface (la) I: of the arc electrode (1), the arc is pulled away from the contact/departure surface (la) by the magnetic force generated from the current flowing through the current path formed by the arc itself. and reaches the electrode pedal (2a). And now the electrode pedal (2
When a magnetic flux Φ is generated by the electric current flowing through the electrode pedal (2a) as shown in Figure 2, the magnetic body (4) on the back of the electrode pedal (2a)
a) further energizes this magnetic flux Φ to increase the electromagnetic driving force of the arc. From contact/separation surface (1a) to electrode pedal (2a)
The arc that has reached the electrode pedal (2a) is given a larger magnetic driving force than before due to the action of the magnetic flux Φ energized by the magnetic body (4a), and is reliably moved to the electrode pedal (2a), drawing a trajectory Q. Nishiki is cut off. In other words, in FIG. 2, the magnetic flux Φ generated by the current I in the electrode pedal (2a) is caused by the presence of the magnetic body (4a).
This will increase as the surrounding magnetic resistance decreases. Therefore, the electromagnetic force acting on the arc increases, and as a result, the arc is strongly driven to move. Since the magnetic driving force is increased in this way, it is possible to reliably avoid the inability to break due to stagnation of the arc as in the conventional case.

Figures 5 and 6 show other embodiments of the present invention. In the figures, (5a) is a magnetic body formed in the shape of an opening in cross section, and can be fitted and attached from the back side of the electrode pedal (2a). It is formed like this. With such a magnetic body (5a), it is possible to obtain a large magnetic driving force as in the above embodiment, and it is possible to reliably cut. Furthermore, according to this embodiment, since the magnetic body is formed into a substantially U-shape, the magnetic resistance is further reduced compared to a plate-shaped magnetic body, and the current density in each electrode pedal is increased to some extent, resulting in a magnetic driving force. becomes somewhat larger.

It goes without saying that the breaker of the present invention is not limited to a vacuum breaker, but can be applied to various types of circuit breakers and switches.

〔Effect of the invention〕

As explained below, in the present invention, since a magnetic body is attached to the back side of each electrode pedal, the magnetic driving force that moves the arc can be strengthened, and it is possible to reliably avoid the inability to cut due to stagnation of the arc. can.

[Brief explanation of drawings]

FIG. 1 is a front view of an arc electrode showing an embodiment of the present invention;
Figure 2 is a sectional view taken along the line II-II in Figure 1, and Figure 3 is a cross-sectional view of Figure 1.
FIG. 4 is a perspective view showing the main parts in FIG. 1, FIG. 5 is a cross-sectional view of the main parts showing another embodiment of the present invention, and FIG.
The figure is a perspective view of the main part in FIG. 5, FIG. 7 is a view corresponding to FIG. 1 showing a conventional ground electrode, and FIG. 8 is a cross-sectional view taken along the line ■--■ in FIG. 7. (1)...electrode, (1a)...contact/separation part (center contact part), (2a)-(2
d)... Electrode pedal (arc transition part). (3a) to (3d)...three 17t, (4a) to (
4d) and (5a) to (5d)...magnetic material. In each figure, the same reference numerals indicate the same or corresponding parts. Agent Masuo Oiwa Figure 1 Figure 2y4 Figure 3 Figure 5 Figure 7 Figure 2d Figure 8 2, Name of the invention, circuit breaker 3, person making the amendment, representative Hitoshi Katayama, section 5, details subject to the amendment Detailed explanation column and drawings of the invention in the book. 6. Contents of amendment (1) “Slits (3a) to (3)” on page 3, line 2 of the specification
The statement "d)" is corrected to "slits (3a) to (3d)". (2) Correct Figure 1 as shown in the attached sheet. 7. 1 or more copies of drawings after amendment of catalog of attached documents 48~4d-] 杍乍体

Claims (5)

[Claims] (1) A pair of electrodes are arranged facing each other so as to be able to come into contact with each other through their central contact portions, and a radial slit is formed from the central contact portion of at least one of the electrodes to define an arc transition portion. At the same time, in the breaker which interrupts the arc generated between the two central contact parts by moving the arc transition part toward the outer periphery by a magnetic driving force formed by a current flowing through the arc itself, the arc transition part A breaker characterized by having a magnetic material coated on the back side. (2) The circuit breaker according to claim 1, wherein the electrode is formed into a disk shape. (3) The breaker according to claim 1 or 2, wherein the slit is formed in a spiral shape. (4) The circuit breaker according to any one of claims 1 to 3, wherein the magnetic material is formed as a plate. (5) A breaker according to any one of claims 1 to 3, characterized in that the magnetic material has a substantially U-shaped cross section.