JPS6245401Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vacuum shear breaker, and more particularly to a vacuum sheath breaker that applies an axial magnetic field to an arc generated by contact and separation of electrodes.

Conventionally, in order to improve shearing performance, a so-called vertical magnetic field method was used, which was equipped with a means to apply a magnetic field in the axial direction (same direction as the extending direction of the electrode rod) to the arc generated by the contact and separation of electrodes in a vacuum vessel. Vacuum shields and disconnectors are known. There are two types of magnetic field applying means: one has a coil that generates an axial magnetic field outside the vacuum container, and the other has a coil that generates an axial magnetic field behind the electrode inside the vacuum container. As shown in FIG. 1, a pair of electrodes 2 and 3 are provided in a vacuum container 1 so as to be able to come into contact with each other through a pair of electrode rods 4 and 5 that are introduced so as to be able to approach and separate from each other. A coil 6 of several turns surrounding the outer periphery of the vacuum vessel 1 is connected in series to the outer end of the electrode rod 4 on the fixed side. A helical coil 7, 7 is provided between the inner end of each electrode rod 4, 5 introduced therein and the electrode 2, 3 supported respectively.
are arranged coaxially, and each electrode 2, 3 and electrode rod 4, 5 are connected in series via each coil 7. In addition, Figures 1 and 2
In the figure, 8 is a bellows that maintains the airtightness of the vacuum vessel 1 by introducing the movable electrode rod 5, and 9 is a cylindrical shield that concentrically surrounds each electrode 2, 3, etc. Therefore, in each case, the current (including when an arc occurs) flows directly through the coils 6 and 7, and the necessary longitudinal magnetic field is applied to the arc space.

However, in each of the above-mentioned conventional vacuum shield disconnectors, the electrodes 2 and 3 are placed in an alternating magnetic field generated by the coils 6 and 7, and are generally made of a highly conductive material mainly composed of copper. It is formed.

Therefore, eddy current is generated in electrodes 2 and 3,
The magnetic field generated by this eddy current causes the coil 6,
7 acts to reduce the magnetic field applied to the arc space, which leads to an increase in the size of the coils 6 and 7, causes a phase delay of the magnetic field with respect to the arc current, and reduces the shearing performance due to the residual magnetic field. is causing a decline.

In order to deal with the above-mentioned problem, some electrodes 2 and 3 are provided with radial slits, but the provision of these slits reduces the mechanical strength of the electrodes 2 and 3 and requires complicated reinforcement. There are other problems.

The present invention was developed in view of the above-mentioned problems, and its purpose is to suppress the generation of eddy current in the electrodes by forming the electrodes from stainless steel, and to manufacture the electrodes at low cost. The object of the present invention is to provide a so-called vertical magnetic field type vacuum breaker which can dramatically increase the breaker performance. Hereinafter, embodiments of this invention will be described in detail with reference to the drawings from FIG. 3 onwards.

3 and 4 are front views and partially sectional front views of essential parts of a first embodiment and a second embodiment of a vacuum shield disconnector according to the present invention, respectively. The vacuum shield disconnectors of the first and second embodiments have the coil 6 disposed on the outer periphery of the vacuum vessel 1 as described above, or the coils 7, 7 disposed on the respective electrodes 2, 7 within the vacuum vessel 1. Since the electrode material etc. are changed from the one installed on the back of 3, components that perform the same functions as those of the conventional vacuum shield and disconnector will be described with the same reference numerals. omitted.

That is, the inner ends of the electrode rods 4 and 5, which are introduced into the vacuum vessel 1 in a manner that allows them to approach and separate freely in the vacuum chamber breaker of the first embodiment, are made of, for example, SUS27 (JIS
(AISI304)) or austenitic stainless steel such as SUS28 (JIS (AISI304L)), electrodes 2 and 3 formed into approximately disk shapes are fixed coaxially by brazing or the like.

Further, the electrode rods 4 and 5 introduced into the vacuum vessel 1 in the vacuum chamber breaker of the second embodiment so as to be able to approach and separate from each other.
The electrodes 2, 3, which are made of austenitic stainless steel similar to the electrodes 2, 3 of the first embodiment and formed into a cap shape, are fitted into the ends of the coils 7, 7, which are integrally provided at the inner ends of the coils 7, 7. They are fitted together and fixed by brazing or the like.

Note that the shape of the electrodes 2 and 3 is not limited to the case where they are formed into a disk shape or a cap shape as in the first and second embodiments described above. Cylindrical shield parts 2a and 3a extending toward the ends of the electrode rods 4 and 5 or the coil 7 are integrally molded in the parts to protect the bellows 8, the coil 7, etc. from arcs, and to protect the electrodes inside the vacuum vessel 1. It may be possible to try to alleviate this.

FIG. 6 is a partially cutaway perspective view of a main part of a fourth embodiment of the vacuum shield breaker according to the present invention. The vacuum shield breaker of this embodiment is similar to the coils 6 and 7 of the first, second and third embodiments described above.
is formed in a spiral shape arranged around the outer periphery of the vacuum vessel 1 or formed in a spiral shape provided at the back of the electrodes 2 and 3. The difference is that the coil 7 has one turn. In addition, in the vacuum shield disconnectors of this fourth embodiment and the fifth and sixth embodiments to be described later, constituent members that perform the same functions as those of the conventional ones will be described with the same reference numerals. The explanation will be omitted.

That is, at the inner ends of the electrode rods 4 and 5, which are introduced into the vacuum vessel 1 so as to be able to approach and separate, in the vacuum shield disconnector of the fourth embodiment, there is a disk-like shape having approximately the same diameter as the electrode rod 4.5. The formed electrode support member 10 is fixed with an insulating spacer 11 made of a high resistance material or an insulating material interposed therebetween. Further, near the inner ends of the electrode rods 4 and 5, an annular coil 7 with ends is arranged concentrically, and the electrodes are connected via arm portions 7a and 7b extending radially inward from the respective ends. Support member 1
0 and electrode rods 4 and 5. Each electrode support member 10 has electrodes 2 and 3 formed in the shape of a cap-shaped disk and made of austenitic stainless steel like those of the above-mentioned embodiments.
are fixed coaxially.

FIG. 7 and FIG. 8 are an exploded perspective view and a longitudinal cross-sectional view of a part of the main part of the fifth embodiment of the vacuum shield breaker according to the present invention. In this example,
Similar to the fourth embodiment described above, a coil 7 is disposed behind the electrodes 2 and 3, but the difference is that the coil 7 is of a shunt type. That is, at the inner ends of the electrode rods 4 and 5 introduced into the vacuum container 1 so as to be able to approach and separate from each other, there is a coil 7 formed in a cylindrical shape with a diameter suitably larger than the outer diameter of the electrode rods 4 and 5. , are coaxially fixed by brazing or the like through the center of the outer surface (outer bottom surface) of the bottom. coil 7
A plurality of slits 12 inclined at a predetermined angle with respect to the axial direction are provided on the circumferential side of the coil 7 to divert the current, and a cap-shaped disc made of austenitic stainless steel is provided at the open end of the coil 7. The shaped electrodes 2 and 3 are fixed in such a way as to close this. Inside the coil 7, iron, cobalt,
A magnetic conductive member 14 made of a ferromagnetic material such as nickel or an alloy thereof, has a disk shape with a suitably smaller diameter than the inner diameter of the coil 7, and has a plurality of axial slits 13 in its body, and a high resistance material. Or a disc-shaped insulating spacer 15 made of an insulating material,
They are fixed to each other and arranged in the axial direction and fixed to the coil 7 and the electrodes 2 and 3, respectively.

9 and 10 are an exploded perspective view and a partially cutaway front view of essential parts of a sixth embodiment of the vacuum shield breaker according to the present invention. In this example,
In contrast to the fifth embodiment described above, in which the coil 7 is of a shunt type by providing the slit 12, the coil 7 is of a shunt type by providing the slit 12, whereas the coil 7 is of a branching type by providing the slit 12. The coil pieces are combined to form a shunt type coil 7. That is, at the inner ends of the electrode rods 4 and 5 introduced into the vacuum container 1 so as to be able to approach and separate from each other, there are arm portions 7c whose bases are fixed to the outer peripheral surfaces of the electrode rods 4 and 5 and which extend in a radial outward direction. A plurality of coil pieces 7' each having an arc-shaped coil portion 7d integrally formed at the tip thereof are attached so as to be equally spaced in the circumferential direction within a plane perpendicular to the axial direction. In addition, the electrode rod 4,
A disc-shaped electrode support member 10 is coaxially fixed to the end of the electrode rod 4 with an insulating spacer 11 made of a high-resistance material or an insulating material interposed therebetween. , 5, the base is attached to the electrode support member 1.
A plurality of coil pieces 7'' consisting of an arm portion 7e that is fixed to the outer peripheral surface of 0 and extends radially outward, and an arcuate coil portion 7f that is integrally formed at the tip of the arm portion 7e.
are mounted equidistantly in the circumferential direction within a plane perpendicular to the axial direction. In addition, at the end of the coil portion 7f of the coil piece 7'', a connecting portion 7g that protrudes downward in FIG. The coil element 7' attached to the electrode rods 4 and 5 and the coil element 7'' attached to the electrode support member 10 are connected to the end of the coil portion 7d of the element piece 7'. The respective arm portions 7c and 7e overlap each other in the axial direction.
The electrode support member 10 includes electrodes 2 and 3 in the form of cap-shaped discs made of austenitic stainless steel.
are fixed coaxially.

In addition, when the electrodes 2 and 3 made of austenite stainless steel are used as in each of the above-mentioned embodiments, and a vertical magnetic field proportional to the arc current is applied to the arc space at 20 to 150 (G/KA), the arc Since concentration on the electrode facing surface is prevented and local heating of the electrodes 2 and 3 is prevented, extremely good breakage performance (the breakage capacity is approximately three times that of the case without a longitudinal magnetic field) is achieved. was clarified through experiments.

As described above, in the present invention, a pair of electrodes are introduced into a vacuum container so as to be able to come into contact with each other through a pair of electrode rods that can be moved toward and away from each other. In a vacuum breaker equipped with a magnetic field applying means for applying an axial magnetic field to the arc, each of the electrodes is made of stainless steel. The generation of eddy currents caused by stainless steel is suppressed to an extremely low level due to the fact that the conductivity of stainless steel is approximately 2.1 to 2.4%.
Therefore, in the so-called vertical magnetic field type vacuum shield, the vertical magnetic field generated by the coil is not reduced and is effectively applied to the arc space.
Furthermore, the longitudinal magnetic field in the arc space has an extremely small delay with respect to the arc current, and the residual magnetic field at the current zero point becomes extremely weak, making it possible to significantly improve shearing performance. Further, since it is not necessary to provide a slit in the electrode, the processing can be easily performed, and mechanical strength can be improved.

[Brief explanation of drawings]

FIGS. 1 and 2 are longitudinal cross-sectional views of a conventional vacuum shear breaker of the so-called vertical magnetic field type, and FIGS. 3 and 4 are respectively a first embodiment of the vacuum sheath breaker according to the present invention, and FIGS. FIG. 5 is a front view and partially sectional front view of the main part of the second embodiment, and FIG. FIG. 6 is a partially cutaway perspective view of the main part of the fourth embodiment of the vacuum sheath breaker according to the present invention, and FIGS. 7 and 8 are respectively the fifth embodiment of the vacuum sheath breaker according to the present invention. An exploded perspective view and a longitudinal cross-sectional view of the main parts of the embodiment, and FIGS. 9 and 10 are respectively a perspective view and a partially cutaway front view of the main parts of the sixth embodiment of the vacuum shear breaker according to the present invention. It is a diagram. 1... Vacuum container, 2, 3... Electrode, 4, 5...
Electrode rod, 6, 7...coil.

Claims (1)

[Scope of utility model registration request] A pair of electrodes are introduced into a vacuum container so that they can be brought into contact with each other through a pair of electrode rods that can be moved toward and away from each other.
A vacuum shield disconnector comprising a magnetic field applying means for applying a magnetic field in an axial direction parallel to an arc generated between a pair of electrodes, wherein each of the electrodes is formed of austenitic stainless steel. Disconnector.