JPS6319054B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vacuum interrupter, and more particularly to a vacuum interrupter comprising means around an electrode for generating an axial magnetic field parallel to an arc.

Conventionally, a vacuum interrupter that is equipped with a means for generating an axial magnetic field (vertical magnetic field) around an electrode is usually made of glass or the like by connecting both openings of an insulating cylinder to a metal end plate through sealing fittings fixed to both ends. to close the container and evacuate the inside to a high vacuum to form a vacuum container,
A pair of disk-shaped electrodes are provided in this vacuum container so that they can be mechanically brought into contact with and separated from each other through a pair of electrode rods that are introduced from the center of each metal end plate so that they can approach and separate from each other. In addition, each electrode and each electrode rod are arranged in the back of each electrode in order to generate an axial magnetic field of the same polarity, and are arranged in the shape of an end ring or in the form of a ring divided into two or more parts in the circumferential direction, and are substantially the same as the electrodes. They are electrically connected in series via a coil with an outer diameter.

However, conventional axial magnetic field type vacuum interrupters use an axial magnetic field to confine the arc generated by the contact and separation of the electrodes in the space between the electrodes to stabilize it, and to reduce the radial (transverse) magnetic field. Although it can be increased more than that of the method,
There is a problem in that the arc spots on the electrode surface are not scattered near the outer periphery of the electrode and are concentrated and unevenly distributed near the center or on concentric circles around the center, making it impossible to utilize the electrode surface effectively. .

This phenomenon is achieved by separating two coils that generate magnetic fields of the same polarity by a predetermined distance in the axial direction, and
As is clear from Figure 1, which shows the experimental results of measuring the radial distribution state of the combined axial magnetic field from both coils by keeping both coils the same and changing their outer diameters, the combined axial magnetic field This seems to be due to the non-uniform distribution state in the radial direction. In other words, in Figure 1, the horizontal axis is the outer diameter R of the coil, and the vertical axis is the intensity H of the combined axial magnetic field, and the diameter of the combined axial magnetic field when the outer diameter R of the coil is changed. The distribution state of the direction is shown by curves A, B, C, and D in the order of increasing outer diameter R of the coil. According to this, when the outer diameter R of the coil is small, as shown by curve A , when the strength H of the composite axial magnetic field is the highest at the center O of the coil, and when the outer diameter R of the coil is large, the strength H of the composite axial magnetic field is as shown by curves B, C, and D. The strength H is lowest at the center O of the coil and highest near the inner circumference of the coil, forming a concave shape, and as the outer diameter R of the coil increases, the lowest and highest points tend to decrease, and the resultant axial magnetic field In other words, it can be seen that uneven distribution of arc spots is caused by uneven distribution of magnetic flux density in the radial direction.

The present invention has been made in view of the above-mentioned problems, and its purpose is to form a concave shape on the outer periphery of a pair of electrodes that are mechanically provided in a vacuum container so as to be freely accessible and detachable through a pair of electrode rods. A first cylindrical coil having one or more axial slits is arranged concentrically in order to generate an axial magnetic field of In order to generate a low-strength axial magnetic field, a second annular coil with a smaller diameter than the first coil and a larger number of circumferential divisions is arranged concentrically, and these first and second coils are connected to a magnetic field of the same polarity. By electrically connecting one or the other electrode to the electrode, the radial distribution of the combined axial magnetic field from both coils is made uniform over the entire surface of the electrode, thereby creating an arc spot. An object of the present invention is to provide an axial magnetic field type vacuum interrupter which is capable of uniformly dispersing the magnetic field and making effective use of the electrode surface. below,
Embodiments of the present invention will be described in detail with reference to FIG. 2 and subsequent drawings.

FIG. 2 is a longitudinal sectional view of a vacuum interrupter according to the present invention. This vacuum interrupter consists of two cylindrical insulating cylinders 1, 1 made of glass, ceramics, etc., made of Kovar etc. fixed to both ends. are coaxially joined through one of the thin-walled annular sealing fittings 2, 2, . Disc-shaped metal end plates 3, 3 consisting of etc.
A vacuum container 4 is formed by closing the interior with a high vacuum and evacuating the inside to a high vacuum. Inside this vacuum container 4, a pair of disk-shaped electrodes 5 and 6 having approximately the same outer diameter are attached to each metal end plate 3, A pair of electrode rods 7 and 8 are introduced from the center of the vacuum container 4 so as to be able to approach and separate from each other while maintaining the airtightness of the vacuum vessel 4. A cylindrical first coil 9 having a slit in the axial direction (vertical direction in FIG. 2) is arranged concentrically on the outer circumference of the electrodes 5 and 6, and together with the first coil 9, the radial direction ( In order to make the magnetic field distribution uniform in the horizontal direction (in the left-right direction in Fig. 2), a first coil is installed on the back of the electrode 5 on the fixed side (the upper side in Fig. 2) with the same diameter as this electrode 5 and the number of divisions in the circumferential direction. The number of annular second coils 10 larger than 9 is arranged concentrically with respect to the fixed electrode rod 7, and the first
The coil 9 and the second coil 10 are electrically connected to the fixed electrode rod 7 and the fixed electrode 5, respectively, to generate axial magnetic fields of the same polarity.

That is, on the inner end surface of the fixed electrode rod 7, there is a third
As shown in the figure, a substantially semicircular protrusion 7a and a stepped portion 7b are formed, and the stepped portion 7b is made of an insulating material such as ceramics or a high-resistance metal such as stainless steel, Hastelloy, Inconel, etc. ,
One surface of a disk-shaped spacer 11 having a thickness equivalent to the height of the protrusion 7a is fixed. and,
The end face of the protrusion 7a of the fixed electrode rod 7 and the spacer 1
As shown in FIGS. 3 and 4, the other surface of the 1 has a cylindrical coil portion 9a having an outer diameter suitably larger than the outer diameter of the electrode rod 7 and has an axial slit 12, and a coil portion 9a. A first connecting arm 9b and a second connecting arm 9c extend parallel to each other in the radial direction (left-right direction in FIG. 2) inward from one cylindrical end (upper end in FIG. 3) of the portion 9a with the slit 12 in between.
The first coil 9 consisting of the first connecting arm 9b
The coil portion 9a is attached to the stationary electrode rod 7 in series through a semicircular connection portion formed at the end of the second connection arm 9c.

At the end of the second connecting arm 9c of the first coil 9, an auxiliary electrode rod 13 having a substantially semicircular protrusion 13a and a step 13b formed on one end surface is arranged in series with the stationary electrode rod 7. Narugashi protrusion 13
is fixed via the end face of a, and the first
The end of the connecting arm 9b is made of an insulating material or a high-resistance metal, and one side is connected to the stepped portion 13b of the auxiliary electrode rod 13.
The other surface of the disc-shaped spacer 14 is fixed to the spacer. A circular recess 15 is provided on the other end surface of the auxiliary electrode rod 13.
The recess 15 is made of an insulating material or a high-resistance metal.
A cylindrical spacer 16 having a length comparable to the depth is concentrically housed with one end fixed to the bottom of the recess 15 . At the other end of the spacer 16 and the other end surface of the auxiliary electrode rod 13, as shown in FIG. 3 and FIG.
Four first arm portions 10b, 10b, . . . extend radially outward from positions divided into four equal parts on the outer circumferential surface of
and 4 curved in the same circumferential direction from the end of each first arm portion 10b by approximately 1/4 turn with a radius of curvature of approximately 40 to 70% (approximately 60% in this embodiment) of the first coil 9.
four second arm parts 10 extending radially inward from the end of each coil part 10c parallel to each first arm part 10b.
d, 10d, ..., each coil part 10c is approximately 1/4 circumference from the end of each second arm part 10d with the inner diameter of the recess 15 and the outer diameter of the auxiliary electrode rod 13 as the inner and outer diameters.
The second coil 10, which is made up of four electrode rod connecting portions 10e, 10e, . has been done. At the other end of the electrode connection part 10a of the second coil 10, the fixed side electrode 5, which is formed in the shape of a disk having approximately the same diameter as the second coil 10, is attached to its back surface (top surface in FIG. 3). The first coil 9 is fitted so as to be spaced apart from each magnetic field generating section 10c through a recess 17 provided in the center, and the fixed electrode is attached to the inner end of the movable electrode rod 8. The movable side electrode 6 formed in the shape of a disk having the same diameter as the movable side electrode 6 is fitted through a recess 18 provided at the center of its back surface (lower surface in FIG. 3).

In addition, in FIG. 2, 19 is a metal bellows;
0 is an intermediate shield concentrically surrounding each electrode 5, 6, first coil 9, etc., and 21, 21 is an auxiliary shield fixed to the inner surface of each metal end plate 3. Further, in FIG. 3, reference numeral 22 denotes a ring-disc-shaped coil auxiliary member fitted onto the auxiliary electrode rod 13 to support the second coil 10, and is made of a high-resistance metal or the like. 9 is also auxiliary supported via a similar coil auxiliary member (not shown), and 23 is a notch provided at the other end of the auxiliary electrode rod 13, which connects the first arm portion 10b of the second coil 10 and the auxiliary electrode rod. This is to prevent direct electrical continuity with 13.

The interruption of the main circuit current by the vacuum interrupter of the first embodiment having the above configuration is similar to that of a normal vacuum interrupter. The arc generated between the electrodes 5 and 6 is completed when electrodes 5 and 6 are sufficiently opened and the current reaches or near a natural zero value and disappears. In addition to taking an axial magnetic field H on the shaft, the axial magnetic field generated by both coils 9 and 10 is expressed by a curve A,
As shown in FIG.
Since an axial magnetic field of substantially uniform strength is applied in the radial direction by the coil 9 and the second coil 10, the arc spot is applied to both electrodes 5 and 6.
It is diffused almost uniformly over the entire surface facing each other.

In addition, in the above-mentioned embodiment, the case where the second coil 10 is arranged on the back of the fixed side electrode 5 has been described, but the invention is not limited to this, and for example, the second coil 10 may be arranged on the back of the movable side electrode 6. In addition to being good, the first coil 9 may also be electrically connected to the movable electrode rod 8 and the like. Further, the first coil 9 has an axial slit 12.
It is not limited to the so-called one-turn type in which one coil is provided, but the number of divisions may be increased within a range smaller than the number of divisions of the second coil 10. Furthermore, the vacuum container 4 is made up of two insulating cylinders 1.
The insulating cylinder of the book and metal end plates 3, 3 that close both ends of the book
For example, it may be formed from one or more insulating tubes and two metal end plates that close both ends of the insulating tube, or it may be formed from a metal tube and an insulating end plate that closes both ends of the insulating tube. Of course, it may be formed.

As described above, the present invention provides a pair of electrodes that are mechanically provided in a vacuum container so that they can be moved toward and away from each other through a pair of electrode rods that are introduced into a vacuum container so as to be able to move toward and away from each other. Alternatively, a cylindrical first coil having two or more axial slits is arranged concentrically, and an annular coil having a smaller diameter than the first coil and a larger number of circumferential divisions is placed on the back of one or the other electrode. A second coil is arranged, and the first coil and the second coil are electrically connected to one or the other electrode and electrode in order to generate a magnetic field of the same polarity. The arc spots that sometimes occur between the electrodes can be uniformly diffused over the entire surface of the electrodes, resulting in effects such as the ability to efficiently increase the capacitance and capacity.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the distribution state of the axial magnetic field in the radial direction with respect to changes in the outer diameter of the coil, FIG. 2 is a longitudinal cross-sectional view of the vacuum interrupter according to the present invention, and FIG.
The figures are longitudinal cross-sectional views of the main parts of the present invention, Figures 4 and 5.
Each figure is a plan view of the main part of the present invention, and FIG. 6 is an explanatory diagram of the operation of the present invention. 4... Vacuum container, 5, 6... Electrode, 7, 8... Electrode rod, 9... First coil, 10... Second coil, 12...
Slits.

Claims (1)

[Scope of Claims] 1. A pair of electrodes are provided in a vacuum container so as to be mechanically movable toward and away from each other through a pair of electrode rods introduced so as to be able to move toward and away from each other, and 1. or a cylindrical first having two or more axial slits.
The coils are arranged concentrically, and a second annular coil having a smaller diameter than the first coil and a larger number of divisions in the circumferential direction is provided on the back of one or the other electrode.
A vacuum interrupter in which a coil is arranged, and the first coil and the second coil are electrically connected to one or the other electrode rod and electrode, respectively, to generate a magnetic field of the same polarity. 2 Set the outer diameter of the second coil to 40 to the outer diameter of the first coil.
70% of the vacuum interrupter according to claim 1.