JPS5987715A - Switch - 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 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 circuit breakers.

First, an example of a conventional electromagnetic contactor will be described with reference to FIG. In Figure 1, (1) is a mounting base made of plastic, (2) is a fixed core laminated with silicon steel plates on this mounting base, and (8) is installed opposite to the fixed core (2) and is similar to this. Movable iron core laminated with silicon steel plates (
4) is an operating coil that provides a driving force to attract and stir the movable iron core (8) and the fixed iron core (2) against a tripping spring (not shown); (5) is made of ij-plastic; A crossbar with a square window, at its lower end holding a moving core (8). (6) is a movable contact inserted into the corner window of the crossbar (5) and held by a push spring (7); (6A) a movable contact provided on the Fi movable contact (6); ) is a fixed contact provided opposite the movable contact (6) and allows current to flow through it, (8A) is a fixed contact provided on this fixed contact (8), and (8C) is also a fixed contact provided on this fixed contact (8). The terminal portion of the contactor (8) is shown.

Therefore, (9) is a terminal screw for connecting the electromagnetic contactor main body with an external circuit, (110) is a base for attaching the fixed contact (8), and (3) is a cover that covers the top surface of the electromagnetic contactor.
Inside thereof, there are a first metal arc extinguishing plate αB) made of a magnetic material and a second metal arc extinguishing plate for extinguishing the arc generated between the fixed contact (8A) and the movable contact (6A). (14-j are provided. In Fig. 2, these metal arc extinguishing plates are marked 0,
0→ shows how the fixed contact (8) and the fixed contact (8A) are attached. This first metal arc-extinguishing plate (191) is constructed as a U-shaped frame that extends over the fixed contact (8) and extends over the fixed contact (8A), and the second metal arc-extinguishing plate (191) (14) is similarly straddled as a single plate on the outside.

Because of the above configuration, in this conventional electromagnetic contactor, when the operation coil (4) is demagnetized, the movable core (8) is separated from the fixed core (2) by a tripping spring (not shown), and the cross spur ( 5) also occupies the state shown in Figure @1,
The fixed contact (8A) and the movable contact (6A) open and an arc (1 smell occurs) between the fixed contact (8A) and the movable contact (6A), but this arc (key is metal arc extinguishing plate OR) ,C1
4, the arc is extinguished at the current zero point, and the current is cut off.

The arc extinguishing process in this conventional electromagnetic contactor is explained in more detail with reference to FIG. 3, which shows a cross section of the arc extinguishing chamber. is attracted to the first metal arc-extinguishing plate (18) made of magnetic material and is stretched like an arc (12A).

At this time, the fixed contact (8) has a U-shaped cross section as shown in Fig. 3, and the arc zero is driven by the magnetic field created by the current flowing through the fixed contact (8). This arc (1 plow) is further elongated. As the arc (old) is elongated in this way, the arc voltage becomes cylindrical.
Dielectric breakdown occurs between the metal arc-extinguishing plate (IB) and the movable contact (6A), and the arc (12A) is divided into two arcs (12B) and (120). One of the divided arcs (120) is attracted to the second metal arc-extinguishing plate 0→, and is driven by the magnetic field created by the current flowing through the fixed contactor (8), and is elongated like an arc (12D). When the arc voltage of this arc (12D) increases, the arc (12D) becomes two arcs (12F
It was further divided into (12F), and the arc (the old one was finally divided into three arcs (12B), (12117), (1
2F), the arc is extinguished at the current zero point, and the current is cut off.

In the conventional switch, arc extinguishing is performed as described above, but the second metal arc extinguishing plate 0 where one end of the arc (12F) occurs
4)), and this arc (12F) is generated at the tip (14A), which has poor thermal conductivity, so sufficient breaking performance can be expected, and the deterioration of the arc extinguishing mechanism is also a significant drawback. was there.

The present invention was made for the purpose of improving the breaking performance of a switch in order to eliminate the drawbacks of steaming.The present invention is characterized by a fixed contact joined to a fixed contact, a a movable contact joined to the movable contact, a first metal arc-extinguishing plate disposed straddling near the tip of the fixed contact in parallel in the contact opening direction to shield these contacts; A second metal arc-extinguishing plate is provided in parallel with the metal arc-extinguishing plate on the side farther from each of the contacts, and the second metal arc-extinguishing plate includes a metal arc-extinguishing plate that corresponds to a portion adjacent to the fixed contact. The present invention consists in providing an arc lead portion that is bent and extended in the extending direction of the fixed contact.

The present invention will be explained below with reference to the embodiment shown in Fig. 4.5.The switch of the embodiment is the same as that of the conventional example above except for the second metal arc-extinguishing plate. A perspective view of only the second metal arc-extinguishing plate α→ is shown. As shown in FIG. 4, this second metal arc extinguishing plate α→ is provided with an arc lead portion (14B) at the lower part of the fixed contact spanning portion, and this extends in the fixed contact extending direction. On the other hand, it differs from the conventional one in that it is bent and extended in parallel. The cross-section of the arc extinguishing chamber to which this second metal arc extinguishing plate α 匈 is applied is shown in Fig. 5.
8A) and the movable contact (6A) until the arc is extinguished.
This arc (12A) is elongated as shown in (12A).
The fact that a) is divided into two arcs (12B) and (120), and this arc (120) is further suctioned and expanded like an arc (12D) is similar to that in FIG.

However, in this example, the arc (12
When D) is again divided into arcs (1'2K) and (12F), the second
The arc is quickly extinguished on the flat surface of the arc lead portion (14B) without causing electric field concentration on the metal arc extinguishing plate α→.

In this way, since effective arc extinguishing is performed in this switch, the electric field concentration on the second metal arc extinguishing plate (14) caused by one end of the arc (12F) occurs, and the thermal conductivity The arc is extinguished at the arc lead portion (14E), which is a good flat surface, and as a result, excellent breaking performance is obtained, which is less likely to cause burnout.

In the above embodiment, the fixed contact (8) is formed in a U-shape, but it goes without saying that the same effect can be obtained even if it is straight rather than U-shaped. .

In addition, in the explanation of steaming, only an example is described where the present invention is applied to a switch that opens and closes using a contact magnet, that is, an electromagnetic contactor, but other switches such as circuit breakers, etc. It is obvious that it can also be applied to

As described above, in the present invention, by providing the second metal arc-extinguishing plate with an arc lead portion that is bent and arranged in parallel with the extending direction of the fixed contact, it is possible to significantly improve the shearing performance. There is an effect that can be done0

[Brief explanation of drawings]

Fig. 1 is a partial sectional view of a conventional switch, Fig. 2 is an enlarged view of the main part showing the arc extinguishing chamber of the switch shown in Fig. 1, Fig. 6 is an explanatory diagram of the arc extinguishing operation of the switch shown in Fig. 1, and Fig. 4 5 is a perspective view showing a second metal arc-extinguishing plate according to an embodiment of the present invention, and FIG. 5 is an explanatory view showing the arc-extinguishing operation of the second metal arc-extinguishing plate according to an embodiment of the present invention. (6)...Movable contact (6A)/Φmovable contact (8)
... Fixed contact (8A) ... Fixed contact (old, (12
A) (1υ) Conflict Φ arc (1B) - First metal arc extinguishing plate (14) Yu φ Second metal arc extinguishing plate (14B) or a substantial portion of the amount. Agent Shin Kuzuno - Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] A fixed contact joined to the fixed contact, a movable contact opposite the fixed contact and joined to the movable contact, and a movable contact arranged in parallel in the contact opening direction and near the tip of the fixed contact in order to shield these contacts. A first metal arc-extinguishing plate arranged astride, and a second metal arc-extinguishing plate arranged in parallel with the first metal plate on the side farther from each contact point of the first metal plate, the second metal arc-extinguishing plate A switch characterized in that the arc extinguishing plate is provided with an arc lead portion that is bent and extended in the extending direction of the fixed contact at a portion close to the fixed contact.