JPH0656730B2 - Switch - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a switch for opening and closing an electric current, and more particularly to an arc extinguishing mechanism thereof.

[Conventional technology]

An electromagnetic contactor and a circuit breaker for wiring can be cited as main switches to which the present invention is applied.

FIG. 5 is a partial cross-sectional view showing a conventional electromagnetic contactor disclosed in, for example, Japanese Patent Laid-Open No. 59-87714. In the figure, (1) is a mounting base made of plastic, (2) is a fixed iron core laminated with silicon steel plates on this mounting base, and (3) is a fixed iron core (2) that is installed opposite to the fixed iron core. Movable iron core laminated with steel plates, (4) is an operating coil that gives a driving force to attract against the movable iron core (3), the fixed iron core (2) and the trip spring (not shown), and (5) is It is a crossbar formed of plastic and has a square window, and its lower end holds the movable iron core (3). (6) is a movable contact (6) that is inserted into the square window of the crossbar (5) and is held by a push spring (7).
(A) is a movable contact provided on the movable contact (6), (8) is a fixed contact provided to face the movable contact (6), and carries a current, and (8A) is the fixed contact. A fixed contact (8C) provided on the contactor (8) is also a terminal portion of the fixed contactor (8).

However, (9) is a terminal screw for connecting the main body of the electromagnetic contactor to an external circuit, (10) is a base for mounting the fixed contactor (8), and (11) is a cover for covering the upper surface of the electromagnetic contactor. Has an arc (12) generated between the fixed contact (8A) and the movable contact (6A).
A metal metal arc extinguishing plate (13) for extinguishing the arc is provided. FIGS. 6 and 7 are enlarged cross-sectional views of the main part of FIG. 5, and as shown in the figure, the metal arc-extinguishing plate (13) has a tongue-like shape in the vicinity of its fixed contact (8). A U-shaped protrusion (13A) is provided by bending the extension.

Due to the above-mentioned configuration, in this conventional electromagnetic contactor, when the operating coil (4) is demagnetized, the movable iron core (3) is separated from the fixed iron core (2) by a trip spring (not shown), and the crossbar (5) also , Occupy the state shown in Fig. 5, fixed contact (8A)
The movable contact (6A) and the fixed contact (8A) and the movable contact (6A).
An arc (12) is generated between the arc (12) and (A), but this arc (12) is extinguished at the current zero point by the metal arc extinguishing plate (13), and the current is cut off or cut off.

The arc extinguishing process of the arc (12) in this conventional electromagnetic contactor will be described in more detail with reference to FIGS. 6 and 7 showing the cross section of the arc extinguishing chamber. As shown in FIG. Contact (6
The arc (12) generated during A) is the first metal magnetic arc-extinguishing plate.
It is sucked by (13) and goes through the state of arc (12D), and then U-shaped protrusion (13A) of metal arc-extinguishing plate (13) like arc (12E).
The curve voltage is extended along the line and the arc voltage is increased. Further, subsequently, fixed contact is made between the movable contact (6A) and the U-shaped protrusion (13A) of the metal arc-extinguishing plate (13) and between the U-shaped protrusion (13A) of the metal arc-extinguishing plate (13). Dielectric breakdown with child (8)
As shown in the figure, it is divided into two arcs (12E) and (12F). When the arc (12) is divided into two in this way, a current flows through the U-shaped protrusion (13A) of the metal arc-extinguishing plate (13), so the divided arcs (12E) and (12F) are U of metal arc-extinguishing plate (13)
Driven by the magnetic field created by the current flowing through the letter-shaped protrusion (13A), it is extended outward as shown by the arcs (12G) and (12H) in Fig. 7 and extinguished at the current zero point. Be cut off.

Since the arc is extinguished as described above, in the electromagnetic contactor to which the present invention is applied, the arc (12) is likely to be divided at the U-shaped protrusion (13A) of the metal arc extinguishing plate (13). ， It can be extinguished by being driven on the metal arc extinguishing plate (13) by the magnetic field created by the electric current flowing through the U-shaped protrusion (13A) of the metal arc extinguishing (13) after being divided. .

[Problems to be solved by the invention]

The conventional switch is extinguished as described above, but there is a problem that the difference in magnetic flux density around the arc is small, the arc cannot be driven at high speed, and the arc cannot be extinguished quickly.

The present invention has been made in order to solve the above problems, and an object thereof is to obtain a switch having an excellent breaking performance that enhances the driving force of the arc and quickly extinguishes the arc.

[Means for solving problems]

The switch of the present invention includes a fixed contact joined to a fixed contact, a movable contact opposed to the fixed contact and joined to a movable contact, bent in a U-shape, and formed in a U-shape at the tip. A metal arc extinguishing plate made of a magnetic material having a projection with a groove cut out, the projection being projected into the opening space of the movable contact in parallel with the both contacts and beyond the both contacts, While passing through the groove, the metal arc-extinguishing plate is erected in parallel with the opening direction of the movable contact so as to extend further than the movable contact.

[Action]

The metal arc-extinguishing plate according to the present invention has a U-shaped groove cut out.
It has a V-shaped projection, and the arc first ignites in this groove. The difference in magnetic flux density between the inside of the U-shaped groove and the notched end is extremely large. Therefore, the arc ignited in the U-shaped groove is strongly driven on the metal arc-extinguishing plate and quickly extinguished.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings, focusing on the differences from the conventional electromagnetic contactor shown in FIG. FIG. 1 is a sectional view of an essential part of an embodiment of the present invention, and FIG. 2 is a perspective view showing a part of the metal arc-extinguishing plate. As shown in Fig. 2, the metal arc-extinguishing plate (13) is bent by a tongue-like extension to project (1
3A) is provided, and U is attached to the tip of the protrusion (13A).
The groove (13B) is cut out. This protrusion (13A) projects close to the fixed contactor (8) in parallel with the open space of the movable contact (6A), crosses the movable contact (6A) fixed contact (8A), and moves to the movable contact (6A).
Pass through the U-shaped groove (13B) and come into contact with and separate from each other.

In order to explain the arc extinguishing operation of FIGS. 1 and 3, the process from the arc (12) occurring between the fixed contact (8A) and the movable contact (6A) to extinguishing the arc in this embodiment is described. Will be described with reference to FIG. The arc (12) generated between the fixed contact (8A) and the movable contact (6A) is first attracted to the metal arc extinguishing plate (13) made of a magnetic material. By the way, in this invention, the U-shaped groove (13B) is cut out in the U-shaped projection (13A), and as shown in FIG. 3, the arc (12) is first formed in this U-shaped groove (13B). , The magnetic flux φ due to the arc current is generated as shown in Fig. 3,
Since the magnetic flux density is extremely large at the point P _{1 and} becomes small at the point P ₂ , the magnetic flux density difference becomes much larger than in the conventional case, so that the arc (12) is strongly driven in the direction of the arrow F.

Furthermore, subsequently, between the movable contact (6A) and the U-shaped projection (13A) of the metal arc-extinguishing plate (13), and between the U-shaped projection (13A) of the metal arc-extinguishing plate (13) and the fixed contact ( 8) Dielectric breakdown occurs between
As shown in the figure, it is divided into two arcs (12E) and (12F). When the arc (12) is divided into two parts in this way, a current flows through the U-shaped projection (13A) of the metal arc-extinguishing plate (13), so the separated arcs (12E) and (12F) are The arc of FIG. 1 is driven more strongly by the magnetic field created by the current flowing through the U-shaped projection (13A) in which the U-shaped groove (13B) of the arc-extinguishing plate (13) is cut off.
Like (12G) and (12H), it is extended outwards and extinguished at the current zero point, and the current is cut off.

Since the arc extinguishing is performed as described above, the electromagnetic contactor to which the present invention is applied has a large arc driving force.
2) is easily divided at the U-shaped protrusion (13A) of the metal arc-quenching plate (13), and after being divided, the U-shaped groove (13
The magnetic field generated by the current flowing through the U-shaped projection (13A) in which B) is cut off is driven at a high speed on the metal arc extinguishing plate (13), and this can be quickly extinguished.

In addition, move the protrusion (13A) into the open space of the movable contact (6A).
(6A) Since it is projected beyond the fixed contact (8A), the arc is driven well regardless of the position where the arc is generated on the contact.

It may be difficult to drive the arc, such as when the protrusion (13A) is projected only up to the movable contact (6A) and the fixed contact (8A), or when an arc occurs at the contact end apart from the protrusion. However, in the present invention, further, when the standing portion (13C) of the metal arc-extinguishing plate (13) extends only to a position lower than the movable contact (6), the arc reaches the standing portion (13C). Even if it extends, the arc voltage becomes very high, and dielectric breakdown is likely to occur near the contact opening space.However, in this invention, since it is extended to a position higher than the movable contact (6), the contact opening An arc is formed at a position away from the separated space, and dielectric breakdown is less likely to occur in the contact opened space.

Needless to say, the present invention can also be expected to have the same effect with respect to a U-shaped fixed contactor (8) having a different shape as shown in FIG.

Further, in the above description, only an example in which the present invention is applied to a switch that opens and closes a contact by a magnet, that is, an electromagnetic contactor is described, but this is applied to, for example, wiring and disconnection. Obviously, it can also be applied to other switches.

〔The invention's effect〕

As described above, according to the present invention, the fixed contact joined to the fixed contact, the movable contact facing the fixed contact and joined to the movable contact, the U-shaped bent end, A metal arc-extinguishing plate made of a magnetic material having a protrusion with a U-shaped groove cut off, and the protrusion is projected into the opening space of the movable contact in parallel with both contacts and beyond both contacts. The movable contact is allowed to pass through the groove, and the metal arc-extinguishing plate is erected in parallel with the opening direction of the movable contact so as to extend further than the movable contact. The effect is to obtain a switch with excellent breaking performance that can extinguish the arc quickly by increasing the driving force of the arc.

[Brief description of drawings]

FIG. 1 is a sectional view showing a main part of a switch according to an embodiment of the present invention, FIG. 2 is a perspective view showing a part of the metal arc-extinguishing plate, FIG. 3 is the same explanatory view, and FIG. FIG. 5 is a partial sectional view showing a conventional switch, showing another embodiment of the present invention.
6 and 7 are sectional views of the same main part. (6) is a movable contact, (6A) is a movable contact, (8) is a fixed contact,
(8A) fixed contact, (12) arc, (13) metal arc-extinguishing plate, (1
3A) is a protrusion, (13B) is a U-shaped groove, and the same reference numerals in the drawings indicate the same or corresponding portions.

Claims (2)

[Claims] 1. A fixed contact joined to a fixed contact, and a movable contact facing the fixed contact and joined to a movable contact,
A metal arc-extinguishing plate made of a magnetic material having a protrusion formed by bending in a U-shape and having a U-shaped groove cut off at its tip end;
The projection is projected into the open space of the movable contact in parallel with both the contacts and beyond the both contacts so that the movable contact passes through the groove and the metal arc-extinguishing plate is movable. A switch which extends in parallel with the contact opening direction and extends up to a distance from the movable contactor so as to stand upright. 2. The switch according to claim 1, wherein the protrusion is provided close to the fixed contact.