JPS5868819A - Electrode for vacuum breaker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrode of a vacuum valve serving as a breaking section of a vacuum breaker, and particularly to an electrode provided with means for generating a magnetic field parallel to an arc.

In order to improve the breaking performance of a vacuum valve, there are many examples of using electrodes that generate a magnetic field parallel to the arc, that is, parallel magnetic field type 'i' poles, and the structure of the vacuum valve 1 is as shown in diagram g1. It has become.

In FIG. 1, 1 is a vacuum valve, and a sealed container is made of an insulator m 2 , RG platelets 3 and 4, and a bellows 5. Inside the container, there is a fixed electrode 6 attached to a fixed holder 7, and a movable one attached to a movable holder 9. Electrodes 8 are arranged. 10 is an intermediate shield electrically insulated from the fixed electrode 6 and the movable electrode 8. The fixed Y electrode 6 and the movable electrode 8 have the same structure.For example, as shown in FIG. It consists of a coil electrode 12 that functions as a coil, and a movable holder 9.

The structure shown in FIG. 2 is obtained by overlapping each of these parts in the direction of arrow 13 in FIG. 3 and joining their contact parts.

The current flowing through the valley is also shown in FIG. In other words, after reaching the center of the coil electrode 12 from the holder 9, approximately half of the current is divided into two directions and goes to the circumference of the coil electrode 12, and each current is divided into two. It flows around the circumference and flows into the arc electrode 11 from the protrusions 12a, 121) of the coil electrode 12. Since the arc point 11 is restricted by @16, it flows only in the radial direction], 5a, and 15b, and reaches the contact portion 11a. The current path at this time is the arc electrode 11.
When viewed from above, it looks as shown by the solid line in Figure G4, and a magnetic field parallel to the arc is generated on the entrance surface of the arc electrode 11 in four regions. If an arc 14 is generated at the contact portion 11a, as shown in FIG. 4, it spreads from the center 1, where the magnetic field is very weak, to the center 1, where the magnetic field is strong, and is extinguished there.

As mentioned above, the feature of the parallel magnetic field forming pole is that it spreads over the arc electrode structure to prevent local melting and improve the breaking performance, but even with such electrodes, the performance is affected by the electrode material. is inevitable. In other words, if a material such as C11-Pl:1 alloy or Cu-B1 metal is used as the material for the arc electrode 11, these materials have high electrical conductivity and thermal conductivity, so they have excellent current carrying performance. Since the material H is a low-melting point material, the electrode surface is melted by the arc, generating a large amount of metal vapor, resulting in poor interrupting performance. The material is Cu.
When alloyed with p e + Cu Q r, CU Q o, etc., these (') are plane j arc, 11
σ1 Voltage 1 (1) Because it is excellent in 4. OK A and 6: B (A), it can handle large currents and has 1 prayer ability, but its conductivity is lower than the above-mentioned alloys, and it has poor thermal conductivity. The rate is also about 25%
11 (to lower the arc electrode 11)
1c, 1.1 (For models with large rated currents and short-time currents, the heat generation of 1 becomes large, and the temperature 1y1 does not satisfy the test standard 11'I-, or the welding phenomenon occurs. Therefore, the electrical conductivity and thermal conductivity are equivalent to Cu-P I) alloys, and the arc resistance is CL,
I-1・゛e0Same money J: If you have the old profit, you can make a 40KA class or 63KA class vacuum valve without any problem. However, in reality, there was no problem in satisfying both of the requirements.Therefore, the structure of the arc electrode 20 as shown in Fig. 5 was used to create a vacuum valve that completely satisfied both the performance of energization and the first and second functions. The arc electrode 20 shown in the figure is made of 4" material such as Cu-Fe alloy, which has good arc resistance and surface voltage performance, and the back surface is made of material such as C1L, which has good electrical conductivity and thermal conductivity. With this type of arc electrode structure, the 11111 arc, surface 1 voltage performance is achieved by the surface arc electrode part 21, and the energization and short-time performance is determined by the surface arc electrode part. 22 has a receiver, and can satisfy both energizing and cutting off performance.

However, in this electrode structure, the front arc electrode part 21, which is expensive and has low conductivity, is made as thin as possible, and on the contrary, the back arc electrode part 22, which is low cost and has high conductivity, is made as thin as possible. Thicker electrodes are more effective in reducing the size and cost of electrodes for large-capacity vacuum valves, but on the other hand,
The outer circumferential edge of the electrode where a high electric field is generated is mostly occupied by the outer circumferential edge of the back arc electrode part 22 which has low withstand voltage performance, and has a disadvantage that the withstand voltage performance is poor and it is unsuitable for use as an electrode for high voltage and large current applications. There is.

The purpose of the present invention is to eliminate the above-mentioned drawbacks, to create an electrode with excellent current carrying performance, breaking performance, and withstand voltage performance, to conduct a large current of 25 K A or more at a voltage of 12 KV class or higher, and to
The purpose is to provide a vacuum valve that shuts off the vacuum.

In the present invention, T and Ne group elements such as Fe, Cr, and Co are bonded to the surface of the back arc electrode part and the outer peripheral end of the coil electrode to achieve full IIU 1-voltage performance, and for high voltage and large current shielding applications. It is used as an electrode.

FIG. 6 shows the electrode 3o according to the present invention, and the surface j voltage covering the front arc electrode part 31, the back arc electrode part 32, the coil electrode 33, the holder 34, the back arc g pole part 32, and the outer peripheral end of the coil electrode 33. The ring layer portion 35 is structured as follows. Surface arc electric resistance 31 has good arc resistance and withstand voltage performance, but has low electrical conductivity and thermal conductivity.
-Alloy materials such as Cr and cll-co. The back arc electrode 32 and the coil electrode 33 are made of C11 or the like, which has high electrical conductivity and high thermoelectric coefficient. The tE pressure ring layer portion 35 is 1″e.

The back arc electrode part 32 and the coil electrode 3 are coated with C-group elements such as Cr and CO by a method such as plating or sputtering.
It is joined to cover the surface of the outer peripheral end of No. 3.

With the structure of this electrode 30, Qu
Since CLI-pe is used for the surface arc electrode, the amount of heat generated by the arc electrode is kept low, and the heat conduction is also better than that of CLI-pe.
Since it is about 4 times more expensive than gold alloy, it has good current carrying performance and short-time current performance.

On the other hand, when analyzing a large current, as explained in Fig. 4,
The arc 14 generated at the main contact part 11a of the arc electrode is m
The arc spreads to the surface arc extinguishing section 31, which is made of a material such as a Cu-1'i'' alloy with good arcing properties, and is extinguished. Immediately after the arc is extinguished, severe re-energization voltage and The impulse voltage applied between the electrodes during opening, etc.
Since the surface of the outer peripheral edge of the electrode, which is subject to high electric fields, is covered with a PE group element that has good withstand voltage performance, it can withstand up to 7 minutes.

7 and 8 show modified examples of the present invention, in which the lft voltage ring layer 35 is formed only on the outer peripheral end surface of the back arc electrode section 32 in FIG. 7, and in FIG. This is carried out only on the surface of the outer peripheral end R portion of the back arc electrode portion 32 and the coil electrode 33, which generates an electric field, and has the same effect as the electrode 30 in FIG. 6.

According to the present invention, a material with good arc resistance and withstand voltage performance is used for the front arc electrode part, and C1,1 with good electrical conductivity and thermal conductivity is used for the back arc '11 tip part, so that the back arc electrode +li Since the surface of the outer peripheral end of the pole is covered with a 'Ji'e group element with good 4-voltage performance,
At high voltages of 12KV class or higher, it has the advantage of being able to produce electrodes at low cost that can quickly perform both large current conduction and cutoff.

[Brief explanation of drawings]

Figure 1 is a vertical sectional view showing a conventional vacuum valve, Figure 2 is a 1:915 diagram showing a conventional electrode, Figure 3 is an exploded view, Figure 4 is a diagram explaining the state of the magnetic field, 5 is a sectional view showing a conventional electrode different from that in FIG. 1, and FIG. 6(A) and a'
3) is a partial plan view and a cross-sectional view showing an embodiment of the present invention, and FIGS. 7 and 8 are cross-sectional views of different embodiments of the present invention. 30... Electrode, 31... Surface portion, 32... Back surface portion, 33... Coil electrode, 34... Holder, 35...
・Withstand voltage phosphorus sugar 30 Figure 5 (A) Figure 60 (B)

Claims (1)

[Claims] 1. At least a pair of arc electrodes that can be brought into contact and separated from each other are arranged in a vacuum vessel, and a rod that extends outside the vacuum vessel from the back surface of the arc electrode is electrically connected between at least one rod and the arc electrode, and In a vacuum breaker having a coil electrode that generates a magnetic field parallel to the arc electrode, the arc electrode uses a material with higher electrical conductivity than the front surface for the front surface that ignites the arc and the back surface of the front surface. An electrode for vacuum breaker featuring the following.