JPH0311494B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotating arc type and self-expanding type switch, which includes a closed container filled with a highly insulating gas, a chamber formed by dividing the inside of the container, and a chamber inside the chamber. a pair of contacts forming an annular electrode that serves as a rotational path for the arc, and an arc whose end surface is covered with a corresponding one of the annular electrodes, the foot of which is locked to the electrode, rotates. A central orifice portion of both the housing portion provided inside one of the contacts that houses the annular permanent magnet that produces a magnetic drive effect, and the annular electrode that cooperates with the annular permanent magnet is radially and a ventilation path for discharging the gas inside the room.

French Patent Application No. 80-07904, filed on April 4, 1980 by the same applicant as the present application, relates to a switch similar to the present application, which is a permanent magnet with a non-through hole in the end face. , or a switch with an annular permanent magnet magnetized with radial polarity, since the permanent magnet obviously has no through-hole and therefore the arc is not blown in two directions. The performance is relatively limited and the breaking current is 10000A.
It stopped below. If an annular permanent magnet is used, the gas will be discharged through the central hole, so
Although it is possible to blow an arc in two directions, it has become clear that the performance of a switch using this method is not much better than the performance limit of the above-mentioned switch using a permanent magnet with a non-penetrating orifice.

As mentioned above, the present invention is based on the discovery that a switch using an annular permanent magnet is not necessarily able to rotate the arc legs effectively, but stays on the contacts. As a result of further in-depth research on this point, it was discovered that there is a part on the end face of a permanent magnet where the lines of magnetic force caused by the magnetic field are locally closed. It has been found that this creates a region where an axial magnetic field is generated, and that the arc tends to move toward that region. In this portion of the axial magnetic field, no rotational force is applied to the arc, and the switch has only the function of a simple self-expanding switch.

It is an object of the present invention to improve such drawbacks and to make the performance of a rotating arc switch using a permanent magnet comparable to that of a rotating arc switch using a blowing coil.

The switch according to the invention is characterized in that said permanent magnet is axially polarized and oriented in a zone adjacent to the cooperating annular electrode, one direction towards the center and the opposite direction towards the outside. a radial magnetic field and an axial magnetic field at the apex forming the boundary between the center and the outside, and the annular electrode facing the cooperating annular electrode extends between them. The switch is arranged such that the arc is within the center of the magnetic field, and the switch is provided with measures such that the cusp transitions towards the exterior of the end face, avoiding any movement of the arc towards this cusp. It is characterized by being

The magnetic field produced by an axially polarized circular permanent magnet is shown in axial cross-section in FIG. It is recognized that the lines of magnetic force are symmetrically closed inside and outside the permanent magnet.

Looking at the example shown in FIG. 1, the lines of magnetic force exhibit centripetal nature in the center of the permanent magnet, and exhibit centrifugal behavior in the portions facing outside. and,
A zone where the magnetic field lines are parallel to the axis separates these centripetal and centrifugal magnetic field lines. This zone should correspond to the position of the axial magnetic field lines, and is also the cusp where both curved magnetic field lines touch, and also serves as a substantially neutral zone of the magnetic pole face of the permanent magnet, and the arc has zero rotational blowing effect due to magnetic force. It shows a tendency to move towards this zone.

The present invention moves such cusps outward from the pole tip face to a zone where they are no longer sensitive to arcs.

In the first embodiment of the present invention, the tubular yoke provided in the hollow part of the annular permanent magnet allows
The transition of the cusp to the outer periphery of the permanent magnet is realized. This tubular yoke distorts the magnetic field spectrum and moves the cusps outward from the permanent magnet. As further detailed below, the provision of the yoke creates a second magnetic field zone in which there is a large axial magnetic field component.
It will appear near the end of the yoke, and the gas spray effect is at its maximum in this zone, so
Arc extinction occurs rapidly.

In a second embodiment of the present invention, the outer diameter of the permanent magnet is made significantly larger so that the apex moves away from the orifice, which is the inner hole of the magnet.

It is advisable to make the contacts facing the permanent magnets tubular so that they serve as second gas outlets and provide double blowing to the arc. The inner diameter of this tubular contact matches the inner diameter of the inner hole of the annular permanent magnet. It is clear that the counter-contact described here can itself also be provided with a spray-like annular permanent magnet, in which case the entire structure is completely symmetrical.

Electric current is passed through the outside of the annular permanent magnet through electrodes that surround the outside of the magnet in a cap-like manner, as described in the above-mentioned pending French patent.
This is for the purpose of completely preventing the possibility that the permanent magnet will be demagnetized. This is also to further center the arc due to the loop effect.

Various embodiments based on the present invention described in detail below have various performances and features in addition to those described above, but these are merely illustrative and do not limit the scope of the present invention. These embodiments are shown in the figures below.

FIG. 1 is a schematic longitudinal section showing the spectrum of the magnetic field due to the annular permanent magnet in a switch with unsatisfactory performance.

FIG. 2 is a schematic longitudinal cross-sectional view showing the closing position and opening position of the switch according to the present invention on the left and right sides of the center line, respectively.

FIG. 3 is a simplified schematic diagram showing annular permanent magnets and electrodes in a modification of the embodiment of the switch according to the present invention.

In FIG. 1, an annular permanent magnet 10 is magnetized in the axial direction, and one pole face, for example the north pole, is covered with an annular electrode 12 forming a contact. An annular electrode 14 formed of an end surface of a tubular member 16 that forms a contact with the annular electrode 12 is arranged. The inner diameter of the tubular member 16 is substantially the same as the inner diameter of the inner hole of the permanent magnet 10 disposed coaxially therewith. FIG. 1 shows schematically the magnetic field lines, which include centripetal radial field lines 20 and centrifugal radial field lines 22. In the space between the electrodes 12 and 14, the centripetal lines of magnetic force 20 and the centrifugal lines of magnetic force 22 are symmetrically distributed on both sides of the zone in which the axial lines of magnetic force 24 are located. Axial magnetic field lines 24
The zone is located at the cusp 26 on the magnetic pole face of the permanent magnet 10.
This corresponds to The cusp 26 is more accurately a line as a collection of points than a point, and is located on the circumference equidistant from both the inner and outer diameters of the annular permanent magnet 10.

The arc 28 extending between the electrodes 12 and 14 tends to move itself towards the cusp 26;
The arc remains stationary at this cusp 26 because the magnetic field there does not provide a driving force to rotate the arc. It is clear from the above facts that the performance and usefulness of a switch equipped with such a device are severely limited.

FIG. 2 shows a switch that is improved while utilizing the basic elements of the example shown in FIG. The tubular member 16 is as described above. The tubular member 16 is slidably provided so as to be in contact with the annular electrode 12 in the closed position of the switch, and to be in a position separated from this in the open position shown on the right side of FIG. ing. The combined part constituted by the permanent magnet 10 and the electrodes 12 and 14 is housed inside a chamber 30 formed by, for example, a cylindrical container 32. This cylindrical container may also contain a highly insulating gas, e.g.
It is housed in a sealed container 34 filled with SF ₆ gas. The movable tubular member 16 passes through the bottom of the chamber 30 and communicates with the closed vessel 34 through a lateral orifice 36 so that the gas within the chamber 30 can be evacuated into the closed vessel 34. The annular electrode 12 cooperating with the permanent magnet 10 is electrically connected to a cylindrical conductor 38 surrounding the annular permanent magnet 10 from the outside, which cylindrical conductor 38 penetrates the chamber 30 and connects it with the chamber 30 at an orifice 42 . An energized support tube 4 that communicates with the closed container 34
Connected to 0. That is, the energizing support tube 40 passes through the interior of the annular electrode 12 and the permanent magnet 10 to the chamber 30.
It will be easily understood that a second ventilation path 44 is formed for discharging the gas inside into the closed container 34. The combination part consisting of the current-carrying support cylinder 40, the permanent magnet 10, and the annular electrode 12 that cooperates with the latter is incorporated as a fixed part, and when the tubular member 16 slides downward, it is inserted between the two electrodes 12 and 14. Generates an arc.

extends into the interior of the arc chamber 30 and for this purpose the chamber 3
The pressure inside the chamber 30 is increased by heating, whereby the gas passes through the tubular member 16 serving as the movable contact side and the fixed part including the annular electrode 12 and the current-carrying support tube 40 through the respective exhaust air passages 36 and 44 into the chamber 30. More discharge occurs.

The permanent magnet 10 is axially magnetized and the tubular member 1
The magnetic pole surface facing the electrode 14 at the end of the magnetic head 6 is set to, for example, the N pole. A yoke member 46 including a tubular yoke 48 extends into the inner diameter hole 18 of the permanent magnet 10 so as to be in close contact with the inner surface of the permanent magnet and to be on the same plane as the end surface of the permanent magnet.
The yoke 46 further includes a perforated disk 50 that is connected to the tubular yoke 48 and tightly contacts the rear end surface of the permanent magnet 10. The yoke 46 distorts the magnetic field spectrum of the permanent magnet 10, as shown on the right side of FIG.
The cusps 52 of the permanent magnet 10 are biased outward, making the magnetic field spectrum asymmetrical. Centrifugal magnetic field lines 54
wraps around the outside of the permanent magnet, whereas the centripetal magnetic field lines 56 are concentrated toward the end of the tubular yoke 48.

The operation of the switch shown in FIG. 2 is as follows.

When the switch is in the closed position, electric power as shown on the left side of FIG. , so it does not have any demagnetizing effect on the permanent magnet. Further, in detail, the yoke 46 is insulated from each conductive member serving as a current path, or has a significantly high electrical resistance.

In the open position, as shown on the right side of FIG. 2, the arc extends between the electrodes 12, 14, as if a conductive gas cloud were squeezed between the electrodes. This gas cloud is thought to consist of three parts as follows. First, the central portion is placed in and acted upon by a centripetal radial magnetic field 56. The outer part then tries to move itself towards the cusp 52. Then, the inner part is engaged with the inner scoop part of the annular electrode 12. This inner part further extends into the zone of the axial magnetic field, in which the gas discharged via the ventilation channel 44 has a large gas flow blowing effect and rapid arc extinguishment. The central part contains the radial component 5, which is the main part of the magnetic field generated by the permanent magnet 10.
6 receives the magnetic blowing effect. The outer part is centered on the outer part of the gas cloud in the direction opposite to the cusp 52 due to the blowing effect of the gas flow discharged from the ventilation passage and the loop effect caused by the annular electrode and the current flowing from the outside. receives a centripetal force that drives it toward the center.

In this way, the switch becomes capable of breaking the current over a wide range of current values, improving its breaking performance.

Fig. 2 shows a preferred embodiment of the present invention, but as a spraying device using an annular permanent magnet magnetized in the axial direction, the contact facing it is made solid, and a one-way It is also possible to use a combination in which gas is blown out only in the following cases.
It is also possible to similarly arrange two annular permanent magnets symmetrically and have tubular contacts cooperate with each of them. The yoke 46 does not necessarily have to be accompanied by a perforated disk 50 on the rear side, and only the concentration of magnetic lines of force in the front zone needs to be important. The spraying method according to the present invention can be combined with any contact method that can transfer the arc between the annular electrodes 12 and 14. Although the combination with a self-spraying method appears to be most advantageous for the time being, it is also possible to combine it with any other spraying method, in particular with a puff spraying method using a piston. The shape of the yoke 46 may be different from that described above, and the transition of the point 52 of the permanent magnet to a zone remote from the opposing annular electrode 14 may be achieved in different ways, for example as shown in FIG. It may be realized.

FIG. 3 shows only the elements that are inside the chamber 30, namely the movable tubular member 16 and the annular surface 14 facing the fixed part attached to the support tube 40 at its end face. Annular permanent magnet 58 magnetized in the axial direction
is similar to the permanent magnet 10 shown in FIG. 2, but its outer diameter is significantly increased.

An annular electrode 60 that cooperates with the permanent magnet 58 and covers its magnetic pole end face is electrically connected to the support cylinder 40 by a conductive member 62 that surrounds the permanent magnet 58 from the outside.

As described above, the pressure of the gas in the chamber 30 is increased by heat, and the gas is discharged from the air passage 44 through the central hole of the annular permanent magnet 58 and from the air passage formed by the tubular member 16. Since the permanent magnet 58 is not provided with a yoke, the magnetic field is particularly symmetrical with respect to its cusp 64. However, the outer diameter of the annular permanent magnet 58 is large enough to keep the cusp 64 sufficiently far away from the annular electrode 14 to prevent the arc from moving to the cusp 64 by means such as those previously described. It has increased to

The operation of the switch of this embodiment is the same as that illustrated in FIG. 2, so there is no need to describe it again. Obviously, increasing the external dimensions of the permanent magnets 58 can be combined with flux-inducing yokes or any other method of distorting the arc blow field. The outward transition of the cusp 64 is particularly clearly visible in comparison with FIG. For example, good results have been obtained by making the diameter of the circumference defined by the apex 64 substantially twice that of the annular electrode 14.

In the two embodiments described above, it is also preferred that the wall thickness of the tubular member 16 be made thin so that the width of the annular electrode 14 can be reduced in order to accurately position the arc. In addition, if it is possible to reduce the spraying effect on the tubular member 16 side, the diameter of the passage for this spraying is made smaller and the dimensions of the annular electrode 14 are made smaller than the inner diameter of the central orifice of the annular permanent magnet 10 or 58. It may be made smaller.

The present invention has been described with respect to its method of implementation, and it is understood that it is not limited to what is shown in the drawings, but that it encompasses all embodiments that may be considered equivalent.

[Brief explanation of the drawing]

FIG. 1 is a schematic longitudinal sectional view of a switch for explaining the principle of the present invention. FIG. 2 is a schematic diagram of a vertical cross-sectional view showing one embodiment of the present invention, and shows the closed circuit position and the open circuit position on the left and right sides of the center line, respectively. FIG. 3 is a schematic longitudinal sectional view showing another embodiment of the present invention. 10: Annular permanent magnet, 12, 14: Annular electrode,
16: Movable tubular member, 26: Apex, 30: Chamber, 3
2: Cylindrical container, 34: Sealed container, 38: Cylindrical conductor, 36, 42: Orifice, 40: Current-carrying support tube, 44: Second ventilation path.

Claims (1)

[Scope of Claims] 1. A rotary arc type and self-expanding type switch comprising: a closed container filled with a highly insulating gas; a chamber formed by dividing the inside of the closed container; and a switch provided inside the chamber. a pair of contacts forming an annular electrode that serves as a rotational path for the arc, and an end face covered with a corresponding one of the annular electrodes, so that the arc to which the foot is attached to the electrode rotates. an inner portion of one of the contacts containing an annular permanent magnet adapted to produce a magnetic drive effect;
an annular permanent magnet and a vent passageway for exhausting the gas in the chamber through the central orifice of both the annular permanent magnet and the cooperating annular electrode, wherein the permanent magnet is axially magnetized and cooperating with the annular permanent magnet; In the area adjacent to the annular electrode, on the one hand, a radial magnetic field is oriented towards the center in the center and in the opposite direction at the outer periphery, and on the other hand, an axial magnetic field is oriented at the apex at the boundary between said center and the outer periphery. The annular electrode facing the annular electrode is arranged so that an arc extends between the annular electrodes within the magnetic field at the center, and the apex points are arranged in the direction of the outer periphery on the end surface. 1. A switch characterized in that a switch is provided with means for completely preventing the arc from moving to the peak point. 2. The switch according to claim 1, characterized in that the permanent magnet is provided with an internal yoke so that the apex is shifted toward the outer periphery and the magnetic field is asymmetrical. 3. The switch according to claim 2, wherein the internal yoke is a tubular body that extends into the central orifice of the permanent magnet to form a ventilation channel for exhaust. 4. The switch according to claim 2 or 3, wherein the internal yoke further includes, in addition to the tubular body, a disc that covers the rear and end faces of the permanent magnet. 5. Claims 1 to 4, characterized in that the above-mentioned opposing annular electrode is formed by the end surface of a thin-walled tubular member, and the inner diameter thereof is substantially equal to the diameter of the central orifice of the permanent magnet. A switch listed in any of the above. 6. The switch according to claim 5, wherein the tubular member constitutes a second gas exhaust path from the chamber, and its exhaust cross-sectional area is close to that of the ventilation path. . 7. The internal yoke is electrically insulated from the rear end face of the contact, thereby forcing the current path to the outside of the permanent magnet and moving the arc toward the center due to the current loop effect. Claim 5 or 6 characterized by
Switch mentioned in section. 8. The switch according to claim 1 or 5, or 6 or 7, characterized in that a permanent magnet with a larger outer diameter is provided. 9. The switch according to any one of claims 1 to 8, wherein the diameter of the circumference formed by the cusps is at least twice as large as that of the opposing annular electrode. . 10. The switch according to any one of claims 1 to 9, characterized in that an annular permanent magnet is made to cooperate with each of the contacts.