JPS6051763B2 - Vacuum breaker electrode - Google Patents

Description

[Detailed description of the invention] The present invention relates to a newly manufactured electrode in a vacuum chamber.

Figure 1 is a cross-sectional view of the main parts of a commonly used vacuum shield, in which 1 and 2 are the main contacts on the fixed and movable sides, respectively, and 3 and 4 are the main contacts on the fixed side, respectively. and electrodes on the movable side, 5 and 6 are lead rods on the fixed side and movable side, respectively, 7 and 8 are shaft shields on the fixed side and movable side, respectively, 9 is a bellows, 10 and 11 are on the fixed side and movable side, respectively. Flanges 12 and 13 are the main shields, 14 and 15 are the outer shields, 16 and 1
7 is an insulating cylinder, 18 to 21 are connecting members, 22 and 23 are current collecting rings, and 24 and 25 are current collecting plates.

In vacuum cleaners with such a configuration, there is a structure called a spiral electrode as an electrode structure for the purpose of shedding or cutting heavy snow.

The arc extinguishing principle of a vacuum shield breaker using this spiral electrode structure as electrodes 3 and 4 is explained as follows. That is, in FIG. 1, the arc generated between main contacts 1 and 2 moves toward the outer periphery due to its own electromagnetic force and reaches between spiral electrodes 3 and 4. Here, the arc moves further to the outer periphery on the spiral pedal along the spiral groove. The arc that has reached the most extreme part receives an electromagnetic force in an oblique direction due to the vector sum of electromagnetic forces in the radial direction and the circumferential direction due to the current flowing through the pedal part, and is transferred to the second spiral pedal part, and further reaches the final part of the spiral pedal part. By moving one after the other, such as moving to the tip and transferring to the third spiral pedal part, local stagnation is eliminated and excessive melting is prevented, thereby improving the shearing ability. I am measuring. However, when this type of electrode is used, recent direct observations of the arc have shown the following drawbacks.

First of all, when moving along the spiral groove on the pedal toward the tip, the arc column may not move in a concentrated manner, but in a spread out manner.

In other words, the rotational force of the arc is an electromagnetic force caused by the current flowing through the pedals, so if the current flows through the pedals in a concentrated manner, it will be effective in moving the arc, but if the arcs move spread out, they will become parallel arcs, so the effect will be less effective. Power is dispersed and ineffective. Second, since the electromagnetic force generated by the current flowing through the spiral section is in the radial and circumferential directions, the force that moves the arc or transfers the tip of the pedal from one to another is the vector sum of these forces. It becomes an electromagnetic force in an oblique direction,
It doesn't work effectively. Third, in the case of a ring-shaped main contact, as soon as the arc occurs, the arc is concentrated and stagnates at the outer corner of the ring-shaped main contact. It has become clear that this is likely to occur. All of these causes local stagnant melting of the arc, resulting in a decrease in shearing ability. SUMMARY OF THE INVENTION An object of the present invention is to provide an electrode for a vacuum breaker or breaker which is improved so as to eliminate the above-mentioned conventional drawbacks and improve the breaker's breaker capacity.

In order to achieve this object, the present invention has electrodes disposed opposite to each other at the tips of the lead rods on the fixed side and the movable side, respectively, and main contacts fixed to the central recesses provided on the opposing surfaces of these electrodes. , in an electrode for a vacuum switch that performs closing and disconnection by closing and separating both main contacts, the outer periphery of the main contact is formed into an umbrella-shaped slope, and the periphery of the outer periphery is the electrode part. The peripheral part of the electrode is electrically insulated so as not to be directly electrically short-circuited, and the peripheral part of the electrode is formed into one or more substantially sickle-shaped blade parts through a sickle-shaped cut groove, and the tip of the sickle blade part and The root portion of the adjacent sickle blade portion is overlapped in the axial direction via an inclined gap such that the tip is located on the opposite side of the arc running surface with respect to the root portion.

Hereinafter, embodiments of the present invention will be described in detail using FIG. 2 and subsequent figures.

FIG. 2 is a plan view showing one embodiment of the electrode of the vacuum shield disconnector according to the present invention, and FIG. 3 is a sectional view taken along the line X-x'' in FIG. The present invention is applied to the electrode shown in FIG.

Although the movable electrode is illustrated here as an example, the fixed electrode of the present invention is constructed in the same manner as shown in FIGS. 2 and 3. In FIGS. 2 and 3, the electrodes connected to the lead rod 6 in FIG. 1 will be explained as follows.
1 is a sickle-shaped electrode attached to the tip of the lead rod 5;
2 is a reinforcing metal fitting that reinforces this sickle-shaped electrode 31, and 33 is a central recessed portion 3 of the electrode 31, with a protruding central portion 34 on the bottom side.
5 by brazing or the like, the outer peripheral part 36 has an umbrella-shaped slope, and has a gap 37 with the electrode portion around the outer peripheral part 36.

Here, although the reinforcing metal fittings 32 are present in the illustrated example, their presence or absence does not have any effect on the improvement of the cutting ability, which is the objective of the present invention. Further, the outer peripheral end 38 of the main contact 33 is
Approximate diameter of the sickle-blade-shaped groove 40 of the sickle-blade electrode 31 having one or more sickle-blade parts 39 (four sickle-blade parts 39 are shown here) Direction is centrally located. The radial width of the sickle blade portion 39 of the electrode 31 and the cut groove 40
The radial widths of the grooves 40 are the same or are configured to be narrower. Further, as shown in FIGS. 6 and 7, the tip of the sickle blade portion 39 and the base of the adjacent sickle blade portion 39 are different from each other, as shown in FIGS.
With respect to the root portion of the arc 9, the two are superimposed in the axial direction with a gap 42 in between so as to be located on the opposite side of the arc running surface. Note that FIG. 7 is a view seen from the direction of arrow 43 in FIG. 6. Next, the main contact 33 may be made of the same material as the electrode 31, but is preferably made of a material that is resistant to welding.

For example, the electrode 31 is made of pure copper, and the main contact 33 is made of, for example, 0.1
A copper alloy containing ~5% by weight of bismuth may be used. Alternatively, the electrode 31 may be made of pure copper, and the main contact 33 may be made of a beryllium alloy with good welding resistance, withstand voltage, and shearing ability, such as a copper alloy containing 5 to 1% beryllium or pure beryllium. . By configuring the fixed side and movable side electrodes in Fig. 1 as described above, the arc generated between the main contacts can be moved to the flat center of the contact surface of the main contacts by self-electromagnetic force and diffusion force. It reaches the umbrella-shaped outer circumferential part 36 and further reaches the sickle-shaped part 39 separated by the sickle-shaped cut groove 40.

Here, since the entire current flows completely through the sickle blade portion 39, the direction of the electromagnetic force is only in the circumferential direction, that is, a strong electromagnetic force in the rotational direction acts on the arc, eliminating the above-mentioned drawback. As a result, local heating and melting can be extremely reduced, and the shearing ability can be improved. In particular, since the tip of the sickle blade part 39 overlaps the base of the adjacent sickle blade part 39 in the axial direction via the inclined gap 42, the arc in the sickle blade part 39 is Blade part 3
You can quickly move to 9.

In this embodiment, a gap is provided between the outer peripheral part 36 of the main contact 33 and the electrode portion around the outer peripheral part 36,
Although the present invention is electrically insulated to prevent a direct electrical short circuit, the present invention is not limited to this, and the gap between the outer peripheral portion 36 of the main contact 33 and the electrode 31 is provided with a high-resistance metal material, ceramic, etc. By inserting an insulating material and fixing them together, electrical insulation and mechanical strength may be enhanced.

Further, in this embodiment, the outer peripheral end 38 of the main contact 33 is located at the radial center of the sickle-shaped cut groove 40, but the present invention is not limited to this, and the As shown in the figure, the diameter of the main contact 33 is cut into a sickle-shaped groove 40.
The main contact 3 is placed on the sickle blade portion 39 of the electrode 31, which is larger than the main contact point 3.
There may be three outer circumferential ends 38.

In this case as well, as described above, a gap is provided between the outer peripheral portion 36 of the main contact 33 and the electrode 31, or an insulating material such as a metal material or ceramic having high electrical resistance is inserted in place of this gap. With such an electrode structure, arc transfer from the main contact 33 to the sickle blade portion 39 of the electrode 31 is improved. Further, in this embodiment, although the radial groove is not provided at the base of the sickle blade portion 39 of the electrode 31, the present invention is not limited to this, and the fifth groove is provided at the base of the sickle blade portion 39 of the electrode 31. As shown in the figure, a groove 41 may be provided in the radial direction S to lengthen the current path of the sickle blade portion 39, thereby creating a structure in which a stronger electromagnetic force acts on the arc.

Furthermore, the present invention allows the diameter of the main contact 33 to be adjusted to the cut groove 4 of the electrode 31.
It may be made smaller than the 0 portion so that the outer peripheral end 38 of the main contact 33 does not overlap the cut groove 40, but in this case, the breaking ability is inferior to the structures of the above embodiments.

As described above, if the electrode of the vacuum shield breaker according to the present invention is used, the arc generated on the main contact in the vacuum shield breaker is moved outward by the diffusion force in vacuum and the self-electromagnetic force, and the main When the arc reaches the umbrella-shaped outer periphery of the contact, it transfers to the sickle blade part that separates the kerf, making effective use of the circumferential rotational force above the arc's sickle blade part, making it easy to break large currents. It can increase.

In particular, since the tip of the sickle blade overlaps the base of the adjacent sickle blade in the axial direction via an inclined gap, the arc at the sickle blade quickly flows to the next sickle blade. It can be moved and the cutting ability can be further improved. Therefore, compared to the conventional spiral electrode structure, there is an excellent improvement in the shear breaking capacity, and the capacity can be increased for the same size vacuum shear and breakers, and if the capacity is the same, the It is possible to provide a miniaturized vacuum shield and disconnector.

[Brief explanation of the drawing]

Fig. 1 is a schematic front sectional view showing an example of a conventional vacuum shield disconnector, Fig. 2 is a plan view showing an embodiment of the present invention, and Fig. 3 is a sectional view taken along line X-X'' in Fig. 2. , FIG. 4 and FIG. 5 are plan views showing other embodiments of the present invention, FIG. 6 is an enlarged partial cross-sectional view showing the main parts of FIG. 2, and FIG. 7 is a partial cross-sectional view of FIG. 5 is a side view of the electrode section viewed from the direction of arrow 43;
is the fixed side lead rod, 6 is the movable side lead rod, 31 is the sickle-shaped electrode, 33 is the main contact, 35 is the central recess of the electrode, 36 is the outer periphery of the main contact, 37 is the gap, and 38 is the outer periphery of the main contact. End, 39 is a sickle blade portion, 40 is a sickle blade shaped groove, 41 is a groove, 42
indicates a gap.

Claims (1)

[Claims] 1. Electrodes 31 are arranged facing each other at the tips of the lead rods 5 and 6 on the fixed side and the movable side, respectively, and main contacts 33 are fixed in central recesses 35 provided on the opposing surfaces of these electrodes 31, respectively. and
In an electrode for a vacuum shield disconnector that performs closing and disconnection by closing and separating both main contacts 33, the outer circumferential portion 36 of the main contact 33 has an umbrella-like slope, and the periphery of the outer circumferential portion 36 has the above-mentioned shape. Electrically insulated to avoid direct electrical short circuit with the electrode part,
The peripheral portion of the electrode 31 is formed into one or more substantially sickle-shaped sickle blade portions 39 via the sickle-like cut groove 40, and the tip of the sickle blade portion 39 and the sickle blade portion 39 adjacent thereto are formed. An electrode for a vacuum shear breaker characterized in that the base portion and the base portion are overlapped in the axial direction via an inclined gap 42 such that the tip is located on the opposite side of the arc running surface from the base portion. 2. Claim 1, characterized in that the outer peripheral end 38 of the main contact 33 is located approximately in the middle of the sickle-shaped groove 40.
Electrodes for vacuum shields and disconnectors as described in section. 3. The electrode for a vacuum shear breaker according to claim 1, wherein the outer circumferential end 38 of the main contact 33 is located approximately at the center of the sickle blade portion 39 in the radial direction. 4. Claims 1 or 2, characterized in that a high-resistance material or an insulator is inserted between the periphery of the outer peripheral portion 36 of the main contact 33 and the electrode 31, and these three are fixed together.
Electrodes for vacuum shields and disconnectors as described in section. 5. The vacuum according to claim 1 or 2, characterized in that the main contact 33 is made of a copper alloy containing 5 to 10% by weight of beryllium, and the electrode 31 is made of pure copper. Electrode for a breaker. 6. The electrode of a vacuum shield breaker according to claim 1 or 2, characterized in that the main contact 33 is made of pure beryllium, and the electrode 31 is made of pure copper.