JPH03295117A - Switch - Google Patents

Abstract

PURPOSE:To obtain a switch which has an excellent breaking function, and which can effectively cool hot gas by providing multiple plate-shaped metal arc-extinguishing grids above and in parallel to a fixed contact. CONSTITUTION:A metal arc-extinguishing grid 13 is divided into multiple pieces perpendicular to a progressive direction of an arc that is generated at the time of opening or closing a moving contact. When a moving contact 6a and a fixed contact 8a are opened/closed by the actuation of a moving contact 6, in an electromagnetic contact device structured in the abovementioned manner, an arc 12 is generated between the respective contacts 6a and 8a. Since the plural metal arc-extinguishing grids 13 are situated so as to be perpendicular to a progressive direction of the arc 12, the arc 12 is attracted to the outside until it becomes a bow-shaped arc 12b, where inner magnetic field is stronger than the outer magnetic field, and the arc is then transformed into a more angular bow-shaped arc 12c, and is cooled by the metal arc-extinguishing grid 13 until it is extinguished.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a switch that switches on and off current.

[Prior art] As a conventional switch, for example, the Japanese Utility Model Publication No. 63-42447
There is an electromagnetic contactor shown in the publication, and FIG. 5 is a partial sectional view thereof. Since this electromagnetic contactor has a symmetrical structure, only the right φ cross section is shown in the figure.

In the figure, (1) is a mounting base made of plastic, etc., (2) is a fixed core laminated with silicon steel plates on this mounting base (1), and (3) is placed opposite this fixed core (2). Similarly, the movable core (4) is laminated with silicon steel plates, and the movable core (4) is used to provide a driving force to attract the fixed core (2) and the movable core (3) against a tripping spring (not shown). The operation coil (5) is a crossbar made of plastic and has a square window, and the movable iron core (3) is located at the lower end of the crossbar.
is retained. (6) is a movable contact inserted into the corner window of the crossbar (5) and held by a push spring (7); (6a) is a movable contact joined to the movable contact (6); ) is a fixed contact that is provided opposite to the movable contact (6) and conducts current flow, (8a) is a fixed contact joined to this fixed contact (8), and (8b) is this fixed contact. (8) shows the terminal section. (9) is a terminal screw for connecting the electromagnetic contactor main body to an external circuit, (10) is a base for attaching the fixed contact (8), and (11) is a cover that covers the top surface of the electromagnetic contactor. Fixed contact (8a
) and the movable contact (6a), a plurality of plate-shaped metal arc-extinguishing grids (13) made of plate-shaped magnetic metal are provided to extinguish the arc (12) generated between the movable contact (6a) and the arc-extinguishing chamber. ing. As is clear from the figure, this metal arc extinguishing grid (13) is placed opposite the movable contact (6), and the fixed contact (8)
They are arranged above and in parallel with each other and spaced apart from each other by a predetermined distance.

The conventional switch is configured as described above and operates as follows. The movable iron core (3) is activated by excitation of the operating coil (4).
is attracted to the fixed iron core (2), then the operation coil (4)
), the movable core (3) is separated from the fixed core (2) by a trip spring (not shown), and the crossbar (
5) moves to the upper position shown in the figure. At this time, the fixed contact (8a) and the movable contact (8a) are separated, and an arc (12
) and a current I flows in the arc (12). When current ■ flows as shown in Fig. 6(a), a magnetic field is generated by this current I, and this magnetic field is determined by Fleming's left hand rule as follows:
Generates the force that drives the arc (12). The direction of this force F is directed toward the outside of the electromagnetic contact device on the movable contact (6a) side due to the combination of the magnetic field caused by the current flowing in the movable contact (6) and the arc (12) on the movable contact (6a) side, and toward the outside of the electromagnetic contact device. (
On the 8a) side, the direction is inward due to the combination of magnetic fields caused by the current flowing in the fixed contact (6) and the arc (12) on the fixed contact (8a) side. Generally, when a magnetic body (15) is placed in the magnetic field generated by the current path (16) as shown in Figure 6(C), the magnetic flux is drawn into the magnetic body (15) and the magnetic flux density distribution changes. , the left side is dense, the right side (magnetic material side)
becomes sparse, and the current path (16) receives a force Fs in the direction of the magnetic body (15). The metal arc-extinguishing grid (13) corresponds to the magnetic material (15), and the arc (12) corresponds to the current path (1).
6), the force Fs is applied to the arc (12), so the force Fs is applied to the movable contact (6a) side of the arc (12), and the force Fs is applied to the fixed contact (8a) side of the arc (12). A force Fs is pulled from the arc (12), and as a result, a driving force as shown in FIG. 6(b) is applied to the arc (12). Therefore, the arc (12) is replaced by a magnetic metal arc extinguishing grid (13).
The electric current is attracted by the electric current and moves as shown in (12a) in FIG. 5, where it is cooled by the metal arc-extinguishing grid (13) and the current is cut off.

[Problems to be Solved by the Invention] The conventional switch is configured as described above, and a plurality of plate-shaped metal arc-extinguishing plates (13) are cumulatively installed above the fixed contact (6) at predetermined intervals. Therefore, even if the arc (12a) that occurs when the current is cut off and migrates to the metal arc-extinguishing plate (13) becomes dogleg-shaped, the arc length of the arc (12a) is longer than that of the metal arc-extinguishing grid ( Since the interval is limited to 13), there is a problem that the interrupting performance is poor even if this interval is made sufficiently long. Also, arc (12), (12
There is also a problem in that the hot gas cannot be cooled sufficiently with the plurality of plate-shaped metal arc-extinguishing grids (13) because the hot gas flows in a constant direction and the flow rate is restricted.

The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to obtain a switch that has excellent shutoff performance and can efficiently cool hot gas.

[Means for Solving the Problems] A switch according to the present invention is arranged to face a movable contact to which a movable contact that approaches and separates the fixed contact is joined, and is arranged above the fixed contact. A plurality of plate-shaped metal arc-extinguishing grids installed in parallel in parallel are each divided into at least two or more pieces perpendicular to the traveling direction of the arc generated when the movable contact is opened. It is.

[Operation] The switch according to the present invention is constructed by dividing each plate-shaped metal arc-extinguishing grid into at least two parts perpendicularly to the traveling direction of the arc generated when the movable contact is opened. The arc that has transitioned to the metal arc-extinguishing grid becomes bow-shaped, and since the magnetic field on the inside is stronger than the magnetic field on the outside, the arc gradually transitions to a dogleg-shaped arc. Since this dogleg-shaped arc also crosses laterally between the divided metal arc-extinguishing grids, the arc length becomes longer than that of the divided metal arc-extinguishing grids, increasing the arc voltage.

As a result, the current that provides the energy for the arc is reduced, the arc is extinguished smoothly, and the interrupting performance is improved. In addition, with the divided metal arc-extinguishing grid, the hot gas generated by the arc can flow up and down, making the gas flow smoother.Furthermore, the hot gas The cooling effect is also increased.

[Embodiment] FIG. 1 is a perspective view of a metal arc-extinguishing grid of a switch according to an embodiment of the present invention. This metal arc-extinguishing grid is a plate-shaped metal arc-extinguishing grid (13) in the conventional switch shown in Fig. 5.
Instead, this metal arc-extinguishing grid is divided into a plurality of parts perpendicular to the traveling direction of the arc generated when the movable contact is opened, and the cross-sectional shape of each metal arc-extinguishing grid can be arbitrary, such as square or circular.

In FIG. 1, (13) is a plurality of divided metal arc-extinguishing grids, and (14) is the metal arc-extinguishing grid (13).
This is a holding plate that holds the Figure 2 shows the metal arc extinguishing grid (
FIG. 13 is a partial side view of the electromagnetic contactor showing the relative positions of the contacts (6) and (8). In Figure 2,
(6) is a movable contact, (6a) is a movable contact joined to the movable contact (6), and (8) is a fixed contact that is provided opposite to the movable contact (6) and conducts current. , (8a)
is a fixed contact joined to the fixed contactor (8).

In the electromagnetic contactor configured in this way, the movable contactor (6) operates to connect the movable contact (6a) and the fixed contact (8a).
When the contacts open, an arc (12) is generated between both contacts <8a) and (8a) as shown in FIG. Since the plurality of metal arc extinguishing grids (13) are positioned perpendicular to the traveling direction of the arc (12),
As explained in the conventional example, the arc (12) is drawn outward to form a bow-shaped arc (12b), where the inner magnetic field is stronger than the outer magnetic field, and the arc becomes a dogleg-shaped arc (L2c). ) and is cooled by the metal arc-extinguishing grid (13) to extinguish the arc. This transitional dogleg-shaped arc (12c) crosses between each metal arc extinguishing grid (13) in the horizontal direction as shown in Fig. 2, so the plate-shaped arc (12c) as shown in Fig. The length of the arc becomes longer because it also extends in the lateral direction than when using the metal arc-extinguishing grid (13). As a result, the arc voltage increases (which means that the resistance between the contacts has increased) and the current is throttled. Therefore, since the arc energy 12R was mostly dependent on the current 1, if the current 1 becomes smaller, the arc energy becomes smaller, the arc is extinguished smoothly, and the interrupting performance is improved.

In addition, the hot gas generated by the arc flows between the metal arc extinguishing grids (13), but in the case of a plate-shaped metal arc extinguishing grid (13) like the conventional example, the flow is in a fixed direction and the flow rate is limited. In contrast, in this case, the gas flows in the vertical direction as well, making the flow of gas smoother, and the surface area of the metal arc-extinguishing grid is larger than that of conventional plate-shaped metal arc-extinguishing plates, which improves hot gas cooling efficiency. has also improved.

In the above embodiment, an example was explained in which the metal arc-extinguishing grids (13) were equally divided; however, as shown in Fig. 3, metal arc-extinguishing grids ([3]
), or as shown in FIG. 4, the width of each metal arc-extinguishing grid (13) may be arbitrarily selected and arranged.

Further, in the above embodiment, the case of an electromagnetic switch was explained, but it may be a circuit breaker, a disconnector, or other switch.
The same effects as in the above embodiment are achieved.

[Effects of the Invention] As described above, according to the present invention, the metal arc-extinguishing grid is divided into at least two parts perpendicularly to the traveling direction of the arc generated when the movable contact is opened, so that the arc length can be increased. arc extinguishing becomes smoother and interrupting performance is improved.
It has the effect of making the flow of hot gas smooth in the vertical direction, and increasing the surface area (thus improving the cooling effect).

[Brief explanation of drawings]

FIG. 1 is a perspective view of a metal arc-extinguishing grid according to an embodiment of the present invention, FIG. 2 is a partial side view of an electromagnetic contactor showing the relative positions of the metal arc-extinguishing grid and the contacts, and FIGS. The figure is a sectional view of a metal arc extinguishing grill/nod showing another embodiment of the present invention, FIG. 5 is a partial sectional view of a conventional electromagnetic contactor, and FIG. 6(a)
, (b) and (c) are explanatory diagrams for explaining the force that an arc receives from a magnetic field. In the figure, (6) is a movable contact, (6a) is a movable contact, and (8) is an arc. is a fixed contact, (8a) is a fixed contact, (12) is (12
b) , (12c) is a transitional arc, and (13) is a metal rad.

Claims (1)

[Claims] a fixed contact to which a fixed contact is joined; a movable contact to which a movable contact that comes into contact with and separates from the fixed contact is joined; In a switch equipped with a plurality of plate-shaped metal arc-extinguishing grids arranged side by side, each of the metal arc-extinguishing grids is arranged perpendicularly to the traveling direction of the arc generated when the movable contactor is opened and closed. A switch characterized by being divided into the above parts.