JPH0278123A - Switch - Google Patents

Abstract

PURPOSE:To enhance its cutting-off performance by cylindrically forming at least the point of either one of contacts, and limiting the position of the foot of an arc on the side of the contact within the annular portion on the end face of the contact. CONSTITUTION:Since the tip portion of a contact 12 is cylindrical, the position of the foot of an arc 11 generated at the moveable contact 12 during its opening is limited within the annular portion on the end face of the contact 12. Rotary drive is therefore efficiently carried out by the radial components of a magnetic flux phi to the arc 11, so that its cutting-off performance is enhanced. Also, an arc extinguish gas blowed from a storing room 4 is forced to pass through the inside of the second contact 12 and discharged into a tank via a through hole 12a. In this case, the arc extinguish gas is forced to flow therethrough in such a manner that it crosses the arc 11, so that the arc 11 is effectively cooled for further enhancing its cutting-off performance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a switch for opening and closing an electric circuit, and in particular to a switch that uses a magnet that forms cross magnetic flux to drive an arc generated when a contact is opened. This relates to a self-blade arc-extinguishing switch equipped with

[Prior Art] Fig. 2 is a partial vertical cross-sectional view showing the open state of a conventional switch disclosed in, for example, Japanese Patent Application Laid-Open No. 62-287531. ), (2) is a first contact which is a fixed contact attached to the fixed terminal plate (1), and (3) is a first contact (2) provided inside. ), one end of which is attached to the fixed terminal plate (1), (4) is an arc extinguishing gas storage chamber formed inside the outer cylinder (3), (5) is a storage chamber opening which is an inlet/outlet for arc-extinguishing gas to the storage chamber (4).

(6) is an insulating nozzle made of an insulating material that is connected to the other open end of the outer cylinder (3), and this insulating nozzle (6>) is formed with a nozzle inner hole (6a). 7) is an annular magnet made of an insulating material attached to the outer periphery of the insulating nozzle (6), and this magnet (7) is a permanent magnet that forms a magnetic flux (φ) as shown by the broken line in the figure.

(8) is a movable side terminal plate provided opposite to the fixed side terminal plate (1), and (9) is a movable side terminal plate provided so as to be able to reciprocate in the vertical direction in the figure through the movable side terminal plate (8). A second contact (1) is a cylindrical movable contact that approaches and separates from the first contact (2).
0) is provided on the movable side terminal plate (8) and is a second contact (9).
) is a current collector that comes into sliding contact with the

(11) is an arc generated when the second contact (9) separates from the first contact (2).

In the conventional switch configured as described above, the first
When the second contact (9) is separated from the contact (2),
An arc (11) is generated as shown in the figure.

On the other hand, the magnetic flux (φ) due to the magnet (7) is
In the vicinity of , it has a component in the radial direction of the outer cylinder (3). Therefore, the generated arc (11) is caused by this magnetic flux (φ
), but its centrifugal force eventually drives it in the radial direction. The arc (11) stretched out in this way is extinguished by spraying arc extinguishing gas from the storage chamber (4).

[Problem to be solved by the invention] In the conventional switch configured as described above, the second
Since the contact (9) is cylindrical, the generated arc (
11) The position of the foot on the end surface of the second contact (9) is not constant, and the foot of the arc (11) may be located near the center of the end surface of the second contact (9). In this case, since the force of the magnetic flux (φ) is difficult to apply, the arc (11) is not properly rotated and there is a problem that the interrupting performance is deteriorated.

This invention was made to solve the above problems, and by limiting the position of the arc foot on the second contact side, the arc is effectively driven and the breaking performance is improved. The purpose is to obtain a switch that can

[Means for Solving the Problems] A switch according to the present invention is such that at least the tip of the second contactor is cylindrical, and a through hole is formed to penetrate the cylindrical wall of this cylindrical portion. .

[Function] In the present invention, by making the tip of the second contactor cylindrical, the position of the leg of the arc on the second contactor side is limited to the annular portion. Further, the arc extinguishing gas flows from the storage chamber across the arc to the inside of the cylindrical portion of the second contact and flows out through the through hole.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a partial vertical cross-sectional view showing the open state of a switch according to an embodiment of the present invention, and the same or equivalent parts as in FIG.

In the figure, (12) penetrates the movable side terminal plate (8) and is provided so as to be able to reciprocate in the vertical direction of the figure.
), and this second contact (
12) is cylindrical from the tip to the middle,
A through hole (12a) is formed through the cylindrical wall of this cylindrical portion. Moreover, this second contactor (12) is adapted to slide in the nozzle inner hole (6a) of the insulating nozzle (6) when opening and closing.

In such a switch, since the tip of the second contact (12) is cylindrical, the movable contact (12)
) is limited to the annular portion of the end face of the movable contact (12). Therefore, the arc (11) is effectively rotated by the radial component of the magnetic flux (φ), and the interrupting performance is improved.

Further, the arc extinguishing gas blown from the storage chamber (4) passes through the inside of the second contact (12) and enters the through hole (12a).
leaks into the tank. At this time, the arc extinguishing gas flows across the arc (11).
) is effectively cooled and the interrupting performance is further improved.

In addition, the position of the through hole (12a) is moved closer to the first contact (2) side (upper part of the figure), so that the through hole (12a) is blocked by the insulating nozzle (6) when the contact is closed, and the storage chamber (4) is closed. ), the energy of the arc (11) at the initial stage of generation will increase the pressure inside the storage chamber (4) when the current is cut off, and the blowing force of the arc-extinguishing gas will also increase accordingly. , the interrupting performance is improved, especially when interrupting small currents.

Furthermore, the position of the through hole (12a) is adjusted to the position of the first contact (2).
If the through hole (12a) is opened even when the station is closed, and the inside of the storage chamber (4) and the tank are communicated with each other, the pressure inside the storage chamber (4) can be prevented from rising excessively when a large current is cut off. can be prevented.

In addition, although the cylindrical second contactor (12) is shown in the above embodiment, the second contactor may have a polygonal shape as long as at least the tip thereof is cylindrical. In addition, through holes (1
Any number of 2a) may be provided, and the shape is not limited.

Further, in the above embodiment, the second contact (12) is a movable contact, but the first contact may be a movable contact and the second contact may be a fixed contact. good.

[Effects of the Invention] As explained above, in the switch of the present invention, at least the tip of the second contact is cylindrical, so the position of the arc foot on the second contact side is adjusted to the second contact. The arc can be limited to the annular portion of the tip surface of the contact, and the arc can be effectively driven and the interrupting performance can be improved. In addition, since a through hole is formed in the cylindrical wall of the cylindrical part of the second contact, the flow of arc extinguishing gas at the time of contact opening crosses the arc, effectively cooling the arc, and improving interrupting performance. can be further improved.

[Brief explanation of the drawing]

FIG. 1 is a partial vertical sectional view showing an open state of a switch according to an embodiment of the present invention, and FIG. 2 is a partial vertical sectional view showing an example of a conventional switch. In the figure, (2) is the first contact, (4) is the storage chamber,
(6) is an insulated nozzle, (6a) is a nozzle inner hole, (7) is a magnet, (11) is an arc, (12) is a second contact, (
12a) is a through hole. In each figure, the same reference numerals indicate the same or corresponding parts. 1st Figure 12a: Through hole Figure 2

Claims (1)

[Claims] A storage chamber capable of storing arc-extinguishing gas, an insulating nozzle connected to the storage chamber and having a nozzle inner hole formed therein, a first contact provided in the storage chamber, and a first contactor inserted into the nozzle inner hole. a second contact that is attached to the first contact so as to be able to come into contact with and separate from the first contact, has a cylindrical tip at least, and has a through hole that penetrates the cylindrical wall of the cylindrical portion; , a magnet provided around the inner hole of the nozzle, which drives an arc generated between the first contact and the second contact by magnetic flux when the contact is opened. vessel.