JPH0782796B2 - Switch - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a switch, and more specifically, at least one pair of contacts together with an arc-extinguishing plate having a horseshoe-shaped groove for cooling an arc. The present invention relates to a switch housed in an enclosure made of an insulator and having an arc runner attached to a fixed contact.

[Conventional technology]

1 and 2 show a conventional switch of this type, in which a fixed contact 3 and a movable contact 4 are attached to a fixed electrode 1 and a movable electrode 2, which are arranged opposite to each other, and a pair of contacts is provided. Make up a child. The proximal end of the movable electrode 2 is coupled to the operation mechanism portion 5 and the movable electrode 2 is rotated.
A horseshoe-shaped groove is formed in the vicinity of the electrodes 1 and 2, and an arc extinguishing plate 6 for cooling an arc generated between the contacts 3 and 4 is arranged. The enclosure 7 is made of an insulating material and houses the operating part of the switch. The enclosure 7 is provided with an arc or hot gas discharge port 8. An arc runner 9 is attached to the fixed electrode 1.

With the above configuration, when the movable contact 4 is now in contact with the fixed contact 3, electric power is supplied from the power source to the load side via the fixed electrode 1 → fixed contact 3 → movable contact 4 → movable electrode 2. It In this state, when a large current such as a short circuit current flows between the contacts, the operation mechanism section 5 operates to separate the movable contact 4 and the fixed contact 3 from each other. At this time, as shown in FIG. 3, an arc A is generated between the fixed contact 3 and the movable contact 4, and an arc voltage appears between the fixed contact 3 and the movable contact 4. This arc voltage increases as the separation distance of the movable contact 4 from the fixed contact 3 increases. At the same time, the arc A is attracted to the arc extinguishing plate 6 side by the magnetic force and extends, so that the arc voltage further increases. Then, the arc A is extinguished at the current zero point of the arc current, and the current is cut off.

Considering the above operation in more detail, the movable electrode 2 rotates to open the electrode. In this opening operation, the spatial distance between the movable electrode 2 and the fixed electrode 1 is short even if the distance between the abdomen 2a of the movable electrode 2 and the tip 1a of the fixed electrode 1 is small.
On the other hand, the arc A generated between the movable contact 4 and the fixed contact 3
Receives an electromagnetic force from the current flowing through the fixed electrode 1 and the current flowing through the movable electrode 2, and receives a force in the direction of the resultant force. However, this electromagnetic force is relatively small because the current flows linearly when the electrode structure is closed, and therefore,
Generally, the arc A is located at a short distance from the position between the movable contact 4 and the fixed contact 3 to the abdomen 2a of the movable electrode 2 and the tip 1a of the fixed electrode 1 as the movable electrode 2 is opened. Move to and stall there. Therefore, the arc A does not come into contact with the arc extinguishing plate 6 located on the right side of the contacts 3 and 4, and the arc A is not cooled, so that there is a problem that a desired breaking performance cannot be obtained.

Further, even if the distance between the abdomen 2a and the tip 1a is not particularly short as described above, there are many structures having the shortest distance between the fixed contact 3 and the movable contact 4. In this case, the arc A Stays between contacts 3 and 4. Thus, although the arc A is cooled by the arc extinguishing plate 6, contact wear due to the stagnation of the arc on the contacts is promoted, which causes a serious hindrance to the upgrade of the switch breaking capacity.

In order to solve the above problems, the present inventors have proposed a fixed contactor as shown in FIG. That is, the arc runner 19 having a substantially U-shape and having a notch groove 19c formed in the center is fixed to the fixed electrode 11, and the fixed contact 13 attached to the fixed electrode 11 faces the notch groove 19c. It will be done.

The operation of such a structure will be described with reference to FIGS. FIG. 5 shows when the electrodes are closed, and the tip 12a of the movable electrode 12 to which the movable contact 14 is attached extends beyond the position of the movable contact 14 to form an arc horn.
A part of is facing the notch groove 19c of the arc runner 19.
FIG. 6 shows the initial state of contact opening in the current interruption operation,
The arc A generated between the fixed contact 13 and the movable contact 14 along with the opening is temporarily stuck at this position. When the opening progresses and the distance between a part of the arc runner 19 and the tip 12a of the movable electrode 12 becomes shorter than the distance between the contacts 13 and 14, as shown in FIG. , Between the contact points 13 and 14 and between the arc runner 19 and the tip 12a. At this time, the tip 12a acts as an arc horn, and the arc A
Since the distance from the movable contact 14 becomes large due to the transfer, the consumption of the movable contact 14 is significantly reduced. Further, since the arc A is strongly pressed against the arc extinguishing plate on the right side of the contact to be cooled, the current interruption performance is also improved.

[Outline of Invention]

The present invention is intended to further improve the current interruption performance of a switch composed of a fixed electrode having an arc runner and an arc extinguishing plate having a horseshoe-shaped groove as described above. Provided is a switch in which the relative position of the arc extinguishing plate and the arc runner is set so that the position of the bottom of the cutout groove of the arc runner is farther than the position of the bottom of the horseshoe-shaped groove of the plate.

Example of Invention

FIG. 8, FIG. 9 and FIG. 10 show an embodiment, in which the bottom portion 19d of the cutout groove 19c of the arc runner 19 is farther from the fixed contact 13 than the bottom portion 16b of the horseshoe-shaped groove 16a of the arc extinguishing plate 16. Is located in. That is, in FIG. 9, the arc runner 19 and the arc extinguishing plate 16 are arranged in a relative positional relationship in which the bottom portion 19d of the cutout groove 19c of the arc runner 19 is hidden behind the arc extinguishing plate 16. Note that FIG. 10 shows the fixed electrode 11 as having a recess 11a.

Next, the operation will be described. The operation of each part when the current is cut off and the behavior of the arc at the initial stage of opening are exactly the same as those described with reference to FIGS.

When the opening of the movable electrode 12 to which the movable contact 14 is attached is advanced by the rotation of the movable electrode 12, the arc A is transferred to the arc runner 19.

The principle of arc transfer in this embodiment is that the contacts 13, 14 are
Arc transition that is formed so that the hot gas generated by the arc generated between contacts 13 and 14 immediately after the opening of the contact spreads to the space around contacts 13 and 14 and becomes shorter than the distance between contacts 13 and 14 during opening. The dielectric strength of the space between the parts is lowered by this hot gas, whereby the arc is transferred between the transfer parts.

Specifically, the arc transition portion is the tip portion of the movable electrode 12 and the edge portion of the inner peripheral edge of the cutout groove 19c of the arc runner 19. When the arc leg is transferred to the arc runner 19, the electromagnetic force of the current flowing through the arc runner 19 causes the arc leg to travel along the inner peripheral edge of the cutout groove 19c of the arc runner 19 and to position the edge in the most arc-extinguishing plate 16 direction. That is, the arc runner 19 moves to the bottom portion 19d (edge portion) of the cutout groove 19c. Then, in order to quickly apply the cooling action by the arc extinguishing plate 16 to the arc, the arc runner as in the present embodiment is used.
The positional relationship between the bottom portion 19d of the cutout groove 19c of 19 and the bottom portion of the horseshoe-shaped groove 16b of the arc-extinguishing plate 16 is important.

As shown in the present embodiment, the notch groove 19c of the arc runner 19
Since the bottom portion 19d of the arc is cut deeper than the bottom portion 16b of the horseshoe-shaped groove 16a of the arc extinguishing plate 16, a plurality of arc extinguishing plates are formed in the process of driving the arc to the bottom portion 19d of the cutout groove 19c of the arc runner 19.
It is forcibly extinguished by being forcibly brought into contact with 16.

In addition, as shown in FIG. 9, the peripheral edge of the cutout groove 19c of the arc runner 19 is hidden behind the arc-extinguishing plate 16 over the entire circumference thereof. Can be secured across the area.

The same effect can be obtained even if the contactors are not limited to one pair and are composed of a plurality of pairs.

〔The invention's effect〕

As described above, according to the present invention, at least one pair of contacts including the movable electrode to which the movable contact is attached and the fixed electrode to which the fixed contact is attached, and a plurality of horseshoe-shaped grooves are formed. By providing an arc extinguishing plate and an arc runner attached to the fixed electrode, the bottom of the notch groove formed in the central portion is arranged at a position farther with respect to the fixed contact than the bottom of the horseshoe-shaped groove. Is forcibly brought into contact with multiple arc-extinguishing plates in the process of being driven to the bottom of the notch groove of the arc runner, and the arc-extinguishing plate provides a cooling action to reliably and quickly extinguish the arc, significantly improving current interruption performance. There is an effect that can be done.

[Brief description of drawings]

1 to 7 show a conventional switch, FIG. 1 is a partially sectional plan view, FIG. 2 is a sectional view taken along a line II-II in FIG. 1, and FIG. 3 is an operation. FIG. 4 is a partial cross-sectional side view showing a state, FIG. 4 is a partial perspective view of another structure, and FIGS. 5 to 7 are side views of essential parts showing operating states of the one shown in FIG. 4, respectively. 8 to 11 show one embodiment of the present invention, FIG. 8 is a partially cutaway perspective view of a main part, FIG. 9 is a plan view of the main part, FIG. 10 is a side view of the main part, and FIG. The figure is a side view of the main parts showing the operating state. 5 ... Operating mechanism, 7 ... Enclosure, 11 ... Fixed electrode, 12
…… Movable electrode, 13 …… Fixed contact, 14 …… Movable contact, 16…
... Arc extinguishing plate, 16a ... Horseshoe-shaped groove, 16b ... Bottom of horseshoe-shaped groove 16a, 19 ... Arc runner, 19c ... Notched groove, 19d ... Bottom of notched groove 19c. In each figure, the same reference numerals indicate the same or corresponding parts.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shirou Murata 1-8 Midoricho, Fukuyama-shi, Hiroshima Mitsubishi Electric Corporation Fukuyama Plant (56) References JP-A-58-14441 (JP, A) -85265 (JP, U)

Claims (2)

[Claims] 1. A at least one pair of contacts comprising a movable electrode having a movable contact attached thereto and a fixed electrode having a fixed contact attached thereto, a plurality of arc-extinguishing plates having horseshoe-shaped grooves formed therein, and the fixed portion. A switch equipped with an arc runner attached to an electrode, wherein a bottom of a notch groove formed in a central portion is located farther from the fixed contact than a bottom of the horseshoe-shaped groove. 2. The switch according to claim 1, wherein the edge of the cutout groove of the arc runner is located behind the edge of the horseshoe-shaped groove of the arc extinguishing plate.