JPH026170B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a switch that switches on and off current, and particularly to an arc extinguishing mechanism thereof.

The main applicable switches of the present invention include electromagnetic contactors and wiring breakers.

First, an example of a conventional electromagnetic contactor will be explained with reference to FIG. Note that the electromagnetic contactor shown in FIG. 1 is symmetrical. In Fig. 1, 1 is a mounting base made of plastic, 2 is a fixed iron core laminated with silicon steel plates on this mount, and 3 is a fixed iron core installed opposite to the fixed iron core 2, which is also laminated with silicon steel plates. 4 is an operating coil that provides a driving force to attract the movable core 3 and the fixed core 2 against a tripping spring (not shown); 5 is a cross bar made of plastic and having a square window; A movable iron core 3 is held at its lower end. Reference numeral 6 denotes a movable contact which is inserted into the corner window of the cross bar 5 and is pressed and held by a pressing spring 7, and 6A is a movable contact 6.
A movable contact 8 provided on the movable contact 6 is a fixed contact 8 provided opposite to the movable contact 6 to conduct current.
A is a fixed contact provided on this fixed contact 8,
Similarly, C indicates a terminal portion of this fixed contactor 8.

9 is a terminal screw for connecting the electromagnetic contactor main body with an external circuit, 10 is a base on which the fixed contact 8 is attached, and 11 is a cover that covers the upper surface of the electromagnetic contact. The manner in which the fixed contact 8 and the fixed contact 8A are attached is shown in an enlarged manner in FIG.

With the above configuration, in this conventional electromagnetic contactor, when the operation coil 4 is demagnetized, the movable core 3 is separated from the fixed core 2 by a tripping spring (not shown), and the crossbar 5 also returns to the state shown in FIG. When the fixed contact 8A and the movable contact 6A open, an arc 12 is generated between the fixed contact 8A and the movable contact 6A.
However, this arc 12 is extinguished at the current zero point, and the current is suddenly cut off.

By the way, in a conventional electromagnetic contactor, as shown in _FIG . Driving force based on magnetic field
However, since these F ₁ and F ₂ are approximately the same in size and opposite in direction, the arc 12 will stick on _the movable contact 6A and the fixed contact 8A. In this way, since the arc 12 is not driven, conventional electromagnetic contactors cannot obtain good breakage performance, and also have the disadvantage of high contact wear because the arc foot is not transferred to the outside of the contact. It had

In view of the above points, the present invention has been made for the purpose of reducing contact wear and improving the shearing performance by modifying the configuration of the fixed contact itself. A cutout hollow part is bored in the contact near the contact, and an inverted L-shaped arc runner is provided at the contact side end of the hollow part, and the arc runner is electrically connected to the fixed contact.
The arc runner is characterized in that the horizontal side thereof extends above the hollow portion.

Below, the present invention will be explained with reference to the embodiments shown in FIGS. 2 shows the shape of only the fixed contact 8. As shown in the figure, a cutout hollow part 8D is provided near the contact joint part of the fixed contact 8, and
An inverted L-shaped arc runner 8B is cut and raised at the end of the hollow portion 8D near the contact point. Therefore, the current I flowing through the fixed contact 8 is divided into I _1A and I _1B on both sides of the hollow portion 8D, and flows into the arc 12. The forces acting on the arc due to these currents are indicated by arrows in FIG. 4b. This is due to the forces caused by the currents I _1A and I _1B flowing through the fixed contact 8, respectively.
F _1A and F _1B are shown acting in the directions shown, and the resultant force of F _1A and F _1B is shown as F ₁ . On the other hand, the force due to the current flowing through the movable contact 6 is
Indicated by _F2 . Here, in the figure, F ₂ ≒
Since 2F _1A ≒ 2F _1B , F ₂ > F ₁ . Therefore, the arc 12 is connected to the fixed contact arc runner 8.
Arc 1 on fixed contact 8A is driven in direction B.
The second leg is transferred onto the arc runner 8B as shown in FIG. Once transferred to the arc runner 8B, the arc 12 is further driven by the current flowing through the arc runner 8B and runs on the arc runner 8B at a high speed, so that the arc 12 is further elongated and extinguished. According to the above-mentioned electromagnetic contactor, the arc 12 is stretched and runs at high speed on the arc runner 8B and reaches the current zero point, so that the charged particles in the positive column of the arc 12 are quickly diffused, and The cooling effect of the leg portion of the arc 12 is increased, and thereby excellent shrivel cutting performance can be maintained. Furthermore, since the legs of the arc 12 are transferred from the fixed contact 8A onto the arc runner 8B, wear and tear on the fixed contact 8A can be significantly reduced. It goes without saying that even if the fixed contact 8 has a terminal side shape as shown in FIG. 6, the same effect as in FIG. 4 can be obtained.

Further, in the above embodiment, only an example in which the present invention is applied to a switch that opens and closes contacts using a magnet, that is, an electromagnetic contactor, is described.
It is obvious that the present invention can also be applied to switches such as wiring switches and disconnectors.

As described above, according to the present invention, a cutout hollow part is provided in the vicinity of the fixed contact joint of the fixed contact, and the end of the hollow part near the contact has an inverted L-shape electrically connected to the fixed contact. By providing an arc runner with the horizontal side of the arc runner extending above the hollow portion, it is possible to reduce wear on the fixed contacts and significantly improve the shear cutting performance.

[Brief explanation of drawings]

Figure 1 is a partial sectional view of a conventional magnetic contactor, Figure 2 is a partial cross-sectional view of a conventional magnetic contactor.
The figure is an enlarged view of the fixed contact shown in Fig. 1, Fig. 3 is an explanatory view for explaining the arcing operation of the fixed contact in a conventional electromagnetic contactor, and Figs. 4 and 5 are the ones according to the present invention. FIG. 6 is a side view showing another embodiment of the present invention. 6: Movable contact, 6A: Movable contact, 8: Fixed contact, 8A: Fixed contact, 8B: Arc runner, 8
C: Terminal portion of fixed contactor 8; 8D: Cutout hollow portion. In the drawings, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] 1. A fixed contact joined to a fixed contact, and a movable contact arranged opposite to the fixed contact and joined to a movable contact extending in the opposite direction to the fixed contact, and the fixed contact has a contact joint. A cutout hollow part is bored near the part, and an inverted L-shaped arc runner electrically connected to the fixed contact is provided at the contact side end of this hollow part, and the horizontal side of this arc runner is connected to the hollow part. A switch characterized by extending upward.