JPH0134832Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Technical field of the invention] This invention relates to the electrode structure of a vacuum shield and disconnector. [Prior Art] A conventional structure of this type is shown in FIG. In the figure, 1 and 2 are fixed-side and movable-side electrodes, and 3 and 4 are fixed-side and movable-side conductive rods fixed to the electrodes. A vacuum container is composed of end plates 5 and 6 on the fixed side and movable side, a bellows 7, and an insulating container 8. 9 is a shield fixed to the insulating container 8. A spiral structure is available as an electrode structure for the purpose of breaking a large current in a vacuum shield/breaker having such a configuration. Figure 2 is a typical example. In FIG. 2, surface A is the contact surface of the fixed and movable electrodes. 21
24 is a spiral groove extending from the electrode contact surface to the outer diameter and penetrating the electrode. In Figures 1 and 2, when electrodes 1 and 2 are opened while they are in contact and current is being applied from conductive rods 3 and 4, an arc occurs at, for example, point P on the electrode contact surface. . This arc is driven in the _F1 direction, that is, toward the outer diameter of the electrode, by the action of the self-magnetic field, but since there are spiral grooves 21 to 24 in the driving direction, when the arc reaches the spiral groove, it wraps around the groove. Move to the outer diameter. When approaching the outer diameter part, the grooves 21 provided in the electrodes 1 and 2,
22, 23, and 24 bend the current path flowing through the electrode in the circumferential direction, so that it is further driven in the _F2 direction. By driving the arc in this manner, local melting of the electrode surface can be prevented, thereby improving the shearing ability. However, when this type of electrode is used, since there are sharp tip portions 21A to 24A on the outer diameter of the electrode, when a voltage is applied to the electrodes 1 and 2, the tip portions 21A to 24A
In A, dielectric breakdown is likely to occur, and when the driven arc reaches the tips 21A to 24A, the gap between the opposing electrode and the opposing electrode is large, so the tip 2 is temporarily damaged.
The arc stagnates at locations between 1A and 24A, making it difficult for the arc to migrate and causing local melting, resulting in poor shearing performance. [Summary of the invention] This invention was made to eliminate the drawbacks of the conventional ones as described above, and aims to provide an electrode structure that improves the withstand voltage characteristics of the electrode and improves the shearing ability. The purpose is [Embodiment of the invention] Hereinafter, one embodiment of the invention will be described with reference to the embodiment shown in FIG. In Figure 3, side A is the second
As in the figure, this is the electrode contact surface. 121 to 124 are spiral grooves extending from the electrode contact surface in the direction of the outer diameter of the electrode, and 31 to 34 are radial grooves extending from the outer diameter of the electrode toward the center of the conductive rod. The spiral grooves 121 to 124 and the radial grooves 31 to 34 are the third grooves.
As shown in the figure, they are connected to each other, and these grooves penetrate to the back of the electrode. The length of this radial groove (X shown in Figure 3) shall be 2.5 mm or more. In FIG. 3, by forming grooves 31 to 34 in the radial direction of the outer diameter portions of the electrodes 1 and 2, sharp tip portions 21A to 24A are formed on the outer diameter portions of the conventional electrodes. The wide electrodes shown in FIG. 3X are now arranged at narrow intervals with the same width as the grooves 31-34. As a result, it is possible to measure the electric field relaxation at the groove tips 31A to 34A on the outer diameter of the electrode.
Improves arc transition. FIG. 4 is a characteristic diagram showing the change in electric field strength when the length X of the groove in the radial direction is changed.
From the figure, if the radial groove length X is set to 2.5 mm, it is possible to reduce the electric field strength to about 73% compared to conventional products. In fact, if the radial groove length
The length X of the groove in the radial direction must be at least 2.5 mm. In addition, in the leading current fading test, when the rate of occurrence of re-ignition after current fading was investigated between this example and the conventional product, it was as shown in Table 1 below. The arc occurrence rate is improved, and the withstand voltage performance can be improved.

[Effect of idea]

As described above, according to this invention, a plurality of spiral grooves and radial grooves connected to the spiral grooves are provided in the electrode of the vacuum shield and disconnector, and the length of the radial grooves is set to 2.5 mm or more. By doing so, it is possible to improve the withstand voltage characteristics and the shearing performance, and the capacity of a vacuum shear breaker of the same size is increased. The effect of being able to provide a container can be obtained.

[Brief explanation of the drawing]

FIG. 1 shows a cross-sectional view of a vacuum shield disconnector. Figure 2 shows an example of the conventional electrode structure of the vacuum shield disconnector, where Figure 2A is a front view, Figure 2B is a sectional view, Figure 2C is a side view, and Figure 3 is a side view. An embodiment of the electrode structure of a vacuum shield and disconnector according to this invention, in which Fig. 3A is a front view, Fig. 3B is a side view, and Fig. 4 shows the length of the radial groove in the embodiment of this invention. Characteristic diagrams showing the changes in electric field strength when changing 9 are configuration diagrams showing an electrode structure according to another embodiment of this invention. 1, 2... Electrode, 3, 4... Conductive rod, 5, 6...
...End plate, 7...Bellows, 8...Insulating container, 9...
...Cider, 21-24...Spiral groove, 121
~124...Spiral groove, 31-34...Radial groove. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims for Utility Model Registration] (1) An electric circuit is opened and closed by a pair of electrodes which are provided in a vacuum container so as to be able to come and go and which are each attached to a conductive rod, and the arc generated when the electric circuit is opened and disconnected is connected to the conductive rod and the above. In a device that is self-magnetic field driven by a current flowing through a pair of electrodes, at least one of the pair of electrodes has a plurality of spiral grooves extending in the direction of the outer diameter of the electrode from the electrode contact surface at the center of the electrode, and A vacuum shield and disconnector characterized in that a radial groove is provided extending from the portion toward the center of the conductive rod and connected to each of the above-mentioned spiral grooves. (2) Utility model registration claim No. 1 characterized in that a spiral groove is provided from the outer edge of the electrode contact surface.
Vacuum cutter described in (1). (3) The vacuum shear disconnector according to claim 1 or 2 of the utility model registration, in which the spiral groove has a step-like shape.