JPS6378417A - Vacuum valve - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a vacuum valve, and particularly to the structure of an electrode.

(Prior Art) Generally, a vacuum valve has a pair of electrodes (fixed electrodes and A movable electrode) is provided. This electrode is fixed to a current-carrying shaft that is electrically connected to the outside of the vacuum valve, but the movable side ffi shaft is fixed to the vacuum container via a bellows, so that the valve remains in a vacuum state. Driven by an external operating mechanism, the fixed electrode and the movable 11-electrode are constructed in a structure that allows them to be moved toward and away from each other.

Therefore, when blocking the ffi flow, both of the above-mentioned
By opening fi4@, the 1′i flow is blocked by the excellent blocking performance of x(empty). At this time, a vacuum arc is generated between both electrodes, and metal ions and Metal vapor is generated. If this gold M< ion or metal vapor adheres to the inner surface of the insulating cylinder, the withstand voltage will be reduced. Therefore, a metal arc shield surrounding both electrodes is attached to the inside of the insulating cylinder.

Furthermore, when current is applied, the current is applied by bringing both electrodes into contact. At this time, in order to prevent the electrode from being repelled by the electromagnetic force of the applied current, the electrode is pressurized with a certain force or more by the operating mechanism.

Next, details of the above-mentioned electrode will be explained with reference to FIG.

In the figure, an electrode 1 is composed of a main electrode 2, a coil electrode 3 disposed on the back side of the main electrode 2, and a reinforcement 4 disposed at the center. This coil electrode 3 consists of an arm portion extending radially from the center, a coil portion curved in an arc shape from the tip of the arm portion, and a connecting portion connected to the back surface of the main 1u pole 2 at the tip of the coil portion. It is configured. Note that the center portion of the coil electrode 3 is fixed so as to be electrically connected to the current supply @5. Furthermore, the reinforcement 4 is made of a material with high specific resistance, such as stainless steel.

When energized, current flows from the current-carrying shaft 5 to the main electrode 2 via the arm portion, coil portion, and connection portion of the coil electrode 3, and further flows to the other opposing electrode. When the coil electrode 3 is divided into four parts, 1/4 of the combined current flows through each coil part, and the current direction is also the same circumferential direction. Therefore, a coil with 174 turns is provided.
A magnetic field parallel to the arc (longitudinal magnetic field) is generated between the electrodes, increasing the breaking capacity.

(Problems to be Solved by the Invention) In the above-described electrode structure, a material with excellent blocking performance is used as the electrode material. Materials with excellent blocking performance are
Generally, the cutting current value is several amperes. Therefore, in order to suppress opening/closing surges, surges generated by CR surge suppressors, varistors, etc. are suppressed.

As a method that does not use the above-mentioned surge protection device, there is a method that uses a low-surge material for the electrode material. Low-surge materials have low breaking capacity, and even if the electrodes are made larger, there is a limit to the breaking current.

This means that when the current is cut off, if the f8 pole is opened with a large current,
The arc tends to concentrate until the distance between the electrodes is sufficiently widened. At this time, excessive damage is caused to the electrode. Even if the distance between the electrodes is wide enough, if the arc is also ignited at a point where the arc is concentrated when the contact is opened, it will re-ignite due to the influence of excessive damage even after the current zero point, reducing the breaking performance. let

Therefore, the purpose of the present invention is to solve the problem of short circuit. By adopting an electrode structure that moves the arc from the low-surge contact material to the surface of the breaking contact material when interrupting large currents such as Li current, we have provided a vacuum valve that has a large capacity and does not require surge protection. be.

[Achievement of invention]

(Means for Solving the Problems) The present invention provides a main electrode and a PJ: a coil that generates a magnetic field, which can be freely connected to the inside of a vacuum vessel whose openings at both ends of an insulating cylinder are closed with end plates. In a vacuum valve equipped with a pair of electrodes, the diameter of the electrode is larger than that of a coil electrode, a spiral groove is provided in the electrode, and a contactor is arranged at the end of the electrode.

(Function) The direction of the current flowing through ff1tl is limited by the spiral groove, and the arc ignited in the contactor is moved to the electrode.
Further, due to the effect of the longitudinal magnetic field generated by the coil electrode, the arc is stably ignited on the electrode surface inside the contact.

(Example) Hereinafter, an example of the vacuum valve of the present invention will be described with reference to the drawings. In FIG. 1, the vacuum valve 10 is configured such that it can be freely connected to the inside of a vacuum container 13 in which both end openings of an M8 cylinder 11 made of ceramic or the like are closed with end plates 12a and 12b made of a metal material, respectively. A pair of electrodes (fixed electrode and possible IJ electrode) 14°15 are arranged. The movable current-carrying shaft 5 to which the inner cylinder a-electrode 15 of this electrode is fixed is fixed to the end plate 12b of the vacuum vessel 13 via a bellows 1G. Further, an arc shield 17 surrounding both electrodes 14 and 15 is attached to the inside of the insulating cylinder 11.

Next, the fixed electrode 14 and the movable electrode 15 will be explained using FIGS. 2 and 3, which are a sectional view and a front view of the fixed electrode 14. The fixed electrode 14 is the main electrode 22
A plurality of contacts 21. A coil electrode 23 is arranged on the back surface, and between the coil 'j' Ja pole 23 and the current-carrying rod 5,
This is a configuration in which a current-carrying plate 24 and a reinforcement 25 are arranged. The contactor 21 is arranged at a position where the magnetic flux density is sufficiently smaller than the magnetic flux density at the center of the longitudinal magnetic field generated by the coil electrode 23. The main electrode 22 is.

The outer diameter is larger than that of the coil electrode 23, and a slit is cut in a spiral shape. The spiral slit is placed on the outer periphery side of 60% or more of the outer periphery of the coil. The coil electrode 23 includes a center portion, a ridge portion extending radially from the center, a coil portion curved in an arc shape from the tip of the ridge portion, and a connecting portion at the tip of the coil portion. The center of the coil electrode 23.

It is fixed to the back surface of the main electrode 22, and the connection part at the tip of the coil part is fixed to the 1 current-carrying plate 24. The energizing plate 24 is
Coil electrically? 6 connecting the 11 pole 23 and the current-carrying shaft 5
Furthermore, the center of the current-carrying shaft 5 and the current-carrying plate 24 and the coil electrode 2
A reinforcement 25 made of a material with high resistance and strength, such as stainless steel, is arranged between the central portions of the parts 3.

The movable electrode 15 is the same as the fixed electrode 14 except that the cutting direction of the sulin 1- of the main electrode 22 is cut symmetrically in FIG. 3.

Furthermore, the zero current carrying plate 2G and reinforcement 27 will be explained using FIG.
Since the other structures are the same as those described above, the explanation will be omitted.

The diameter of the current-carrying plate 26 is larger than that of the coiled pole 23.
At a position corresponding to the back surface of the contactor 21.

Reinforcement 27 is placed. The reinforcement 27 has both ends fixed to the main electrode 23 and the current-carrying plate 26, respectively.

The structure is as described above, and when the current is cut off, the contact 2
An arc is first ignited on the surface of 1. At this time.

The current flowing on the main electrode flows in a spiral manner due to the spirally cut grooves. This current applies force to the arc in the circumferential direction, causing the arc to move from the contact to the surface of the main electrode. Furthermore, due to the effect of the vertical magnetic field, the arc voltage is lower and more stable at the center than at the outer periphery of the coil.
The arc moves to the center.

This improves breaking performance by quickly moving the arc from the surface of the contact when the current is opened to the electrode that has breaking performance, and also has a large capacity with small surge generation and no need for surge protection. It can be a vacuum valve.

〔Effect of the invention〕

Since the present invention is configured as described above, it is possible to cut off low surge materials! It is possible to provide a vacuum valve that has a large interrupting capacity regardless of its performance and does not require surge protection.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the vacuum valve of the present invention;
FIG. 2 is a sectional view of an electrode section showing one embodiment of the present invention, and FIG.
4 is a sectional view showing another embodiment of the present invention, and FIG. 5 is a sectional view of the electrode portion of a conventional vacuum valve. 2.22...Lord? Hypolar 21...Contactor 3.23...Coil electrode 24.26...Electrifying plate 4.25.27...Reinforcing agent Patent attorney Noriyoshi Chika Yudo Hirofumi Mitsumata Figure 1 Figure 3

Claims (4)

[Claims] (1) In a vacuum valve in which a pair of electrodes, which are movable toward and away from each other and are equipped with a main electrode and a coil electrode that generates a vertical magnetic field, are arranged inside a vacuum vessel whose openings at both ends of an insulating cylinder are closed with end plates. . A vacuum valve, characterized in that the electrode is provided with a spiral groove, and the outer diameter of the coil electrode is smaller than the outer diameter of the electrode. (2) The vacuum valve according to claim 1, wherein the contactor is disposed outside the diameter where the strength of the longitudinal magnetic field is 1/2 or less of the strength of the longitudinal magnetic field at the center. (3) The current-carrying shaft and the tip of the coil portion of the coil electrode are electrically connected by a current-carrying plate, and the electrode and the coil electrode are electrically connected at the center of the back surface of the electrode, as set forth in claim 2. vacuum valve. (4) The vacuum valve according to claim 3, wherein the diameter of the current-carrying plate is larger than the outer diameter of the coil, and the current-carrying plate and the electrode are fixed by reinforcement made of a member having a higher resistance than the coil electrode member.