JP6925232B2 - Vacuum valve contacts and vacuum valves using them - Google Patents

Description

The present invention relates to a contact for a vacuum valve and a vacuum valve using the contact.

A vacuum circuit breaker is a device placed in the power receiving and distribution system, and plays a role of disconnecting a specific part from the power system. In particular, when an accident current occurs, it is responsible for cutting off the current and protecting the power system.
A vacuum valve is provided in the vacuum vessel of the vacuum circuit breaker to energize a current at normal times and shut off the current when an accident current occurs by connecting and disconnecting a pair of contacts.
The vacuum valve has a fixed side contact, a movable side contact, and a bellows that movably supports the movable side energizing shaft connected to the movable side contact and secures the airtightness inside the vacuum container. I have.

The fixed-side contact and the movable-side contact include a cup-shaped electrode and a disk-shaped contact plate that closes the opening of the electrode. Then, a plurality of slits that are inclined in the axial direction are provided in the cylindrical portion of the cup-shaped electrode, and a magnetic field in the electrode axial direction (hereinafter referred to as a longitudinal magnetic field) is applied between the contact plates of the fixed side contact and the movable side contact. Therefore, a longitudinal magnetic field method is adopted to improve the current cutoff performance.
The device of Patent Document 1 is known as a vacuum valve provided with a contact point for a longitudinal magnetic field type vacuum valve. In the vacuum valve of Patent Document 1, the arc generated when the current is cut off is diffused by the longitudinal magnetic field, so that the heat of the contact surface located at the electrode end is diffused, so that the metal vapor forming the arc can be supplied. Achieve limited current interruption.

Japanese Patent No. 6138601

By the way, in the vacuum valve of Patent Document 1 described above, metal vapor generated at the time of current interruption, other plasma particles, and an arc spot generated between a pair of contact portions are transmitted from the axial center of the contact plate to the outer peripheral end portion of the contact plate. After diffusing, it moves from the cylindrical portion of the electrode to the fixed side electrode and the movable side energizing shaft.
If the arc spot moved to the movable electrode shaft moves to the bellows, the bellows may be damaged and the airtightness inside the vacuum vessel may be impaired.
Therefore, the present invention provides a contact for a vacuum valve that eliminates the arc spot moving on the peripheral surface of the cylindrical portion of the electrode at an early stage and does not thermally affect the airtight member of the vacuum valve, and also provides an arc blocking property. It is an object of the present invention to provide an improved vacuum valve.

In order to achieve the above object, the vacuum valve contact according to one aspect of the present invention includes an electrode having a cylindrical portion and a contact plate that closes an opening on one end side of the cylindrical portion. On the outer peripheral surface between two electrode slits adjacent to each other in the cylindrical portion, an electrode groove is formed in which an arc spot generated in the contact plate flows into the contact plate and disappears.
Further, the vacuum valve according to one aspect of the present invention is a device in which the above-mentioned vacuum valve contacts are mounted as a pair of contact parts that can be brought into contact with each other in a vacuum container.

According to the contact for a vacuum valve according to the present invention, the arc spot moving on the peripheral surface of the cylindrical portion of the electrode is not eliminated at an early stage, and the airtight member of the vacuum valve is not thermally affected.
Further, the vacuum valve according to the present invention can improve the breaking property of the arc generated when the current is cut off.

It is a figure which shows the structure of a vacuum valve. It is a figure which shows the structure of the movable side contact part of 1st Embodiment which concerns on this invention. It is a perspective view which shows the structure of the electrode which constitutes the movable side contact part of 1st Embodiment which concerns on this invention. It is a figure which showed the movable side contact part of 1st Embodiment which concerns on this invention in plan view. It is a figure which shows the cross-sectional shape of the electrode groove formed between two adjacent electrode slits of 1st Embodiment which concerns on this invention, and FIG. FIG. 5 (b) is a diagram showing a state in which an arc spot flows into the electrode groove and the arc is in contact with the groove opening edge. It is a figure which shows the cross-sectional shape of the electrode groove formed between two adjacent electrode slits of 2nd Embodiment which concerns on this invention, and FIG. FIG. 6B is a diagram showing a state in which an arc spot flows into the electrode groove and the arc is in contact with the groove opening edge. It is a figure which shows the cross-sectional shape of the electrode groove formed between two adjacent electrode slits of 3rd Embodiment which concerns on this invention, and FIG. 7A is a state just before the arc spot flows into an electrode groove, FIG. FIG. 7 (b) is a diagram showing a state in which an arc spot flows into the electrode groove and the arc is in contact with the groove opening edge. FIG. 8A is a diagram showing a cross-sectional shape of an electrode groove formed between two adjacent electrode slits according to a fourth embodiment of the present invention, and FIG. 8A is a state immediately before an arc spot flows into the electrode groove. 8 (b) is a diagram showing a state in which an arc spot flows into the electrode groove and the arc is in contact with the groove opening edge.

Next, the first to fourth embodiments of the present invention will be described with reference to the drawings. In the description of the drawings below, the same or similar parts are designated by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the plane dimensions, the ratio of the thickness of each layer, etc. are different from the actual ones. Therefore, the specific thickness and dimensions should be determined in consideration of the following explanation. In addition, it goes without saying that the drawings include parts having different dimensional relationships and ratios from each other.
Further, the first to fourth embodiments shown below exemplify devices and methods for embodying the technical idea of the present invention, and the technical idea of the present invention is based on the material of the component parts. The shape, structure, arrangement, etc. are not specified as follows. The technical idea of the present invention may be modified in various ways within the technical scope specified by the claims stated in the claims.

[Vacuum valve of the first embodiment]
FIG. 1 shows an outline of the vacuum valve 1.
In the vacuum valve 1, a fixed-side sealing metal fitting 3 is sealed to one end of a tubular vacuum insulating container 2, and a movable-side sealing metal fitting 4 is sealed to the other end. The fixed-side energizing shaft 5 penetrates and is fixed to the fixed-side sealing metal fitting 3, and the fixed-side contact portion 6 is provided at the end of the fixed-side energizing shaft 5 in the vacuum insulating container 2.
Further, the movable side contact portion 7 which faces the fixed side contact portion 6 and is freely contactable and detachable is provided at the end of the movable side energizing shaft 8 which movably penetrates the movable side sealing metal fitting 4.
Further, the movable side contact portion 7 is provided with a bellows 9 which is connected to the movable sealing metal fitting 4 to movably support the movable side energizing shaft 8 and secure the airtightness of the vacuum insulating container 2.
As shown in FIG. 2, the movable side contact portion 7 closes and fixes the cup-shaped electrode 10 fixed to the end of the movable side energizing shaft 8 in the vacuum insulating container 2 and the opening of the electrode 10. The contact plate 11 and the contact plate 11 are provided.

As shown in FIG. 3, the electrode 10 is a member provided with a cylindrical portion 12 and a bottom portion 13 formed at one end of the cylindrical portion 12 in the axial direction.
A plurality of electrode slits 14 that cross diagonally with respect to the axial direction are formed in the cylindrical portion 12 of the electrode 10 at predetermined intervals in the circumferential direction. Further, between the pair of electrode slits 14 adjacent to each other in the circumferential direction, an electrode groove 15 formed only on the outer periphery of the cylindrical portion 12 and extending in the circumferential direction is formed. As will be described later, the arc spots generated in the contact plate 11 can flow into the electrode grooves 15 to eliminate the arc spots.
As shown in FIG. 4, the contact plate 11 of the movable side contact portion 7 is formed with a plurality of contact slits 16 radially formed on a disk-shaped member. Then, as shown in FIG. 2, the contact plate 11 closes the opening of the electrode 10 with the opening on the outer peripheral side of each contact slit 16 and the upper end opening of each electrode slit 14 facing each other. It is fixed at.

As shown in FIG. 3, the electrode groove 15 extends linearly between a pair of electrode slits 14 adjacent to each other in the circumferential direction and opens at the inner wall of the electrode slits 14, and is opened in FIG. 5 (a). As shown in the above, the groove is formed by forming the outer peripheral surface of the cylindrical portion 12 as a rectangular (square or rectangular) recess. The groove opening edges 15a and 15b of the electrode groove 15 are formed as right-angled corners.
Further, the fixed side contact portion 6 provided at the end of the fixed side energizing shaft 5 also has the same structure as the movable side contact portion 7.
The vacuum valve contact described in the present invention corresponds to the fixed side contact portion 6 and the movable side contact portion 7, and the vacuum container described in the present invention is fixed to the tubular vacuum insulating container 2. It corresponds to the side sealing metal fitting 3 and the movable side sealing metal fitting 4.

Next, the operation of the vacuum valve 1 of the first embodiment will be described.
When an arc (reference numeral 18 shown in FIG. 5A) is generated between the fixed side contact portion 6 and the movable side contact portion 7 when the current is cut off, a cup-shaped electrode of the fixed side contact portion 6 and the movable side contact portion 7 is generated. Since a plurality of electrode slits 14 that cross diagonally with respect to the axial direction are formed in the cylindrical portion 12 of 10, a current flows in the circumferential direction through the cylindrical portion 12. As a result, a magnetic field (vertical magnetic field) parallel to the arc 18 generated between the contact plate 11 of the fixed side contact portion 6 and the movable side contact portion 7 is applied. In this way, when a longitudinal magnetic field is applied to the arc, the arc 18 is diffused and stabilized, and the arc voltage between the contact plate 11 of the fixed side contact portion 6 and the movable side contact portion 7 is reduced.

Here, the arc spot 17 generated at the center position of the contact plate 11 of the fixed side contact portion 6 and the movable side contact portion 7 diffuses to the outer circumference of the contact plate 11 and then moves along the outer peripheral surface of the cylindrical portion 12. To go.
That is, as shown in FIG. 2, the arc spot 17 generated in the contact plate 11 of the movable side contact portion 7 moves along the outer peripheral surface of the cylindrical portion 12 to the movable side energizing shaft 8 side indicated by the arrow C direction. go.
As shown in FIG. 5A, the arc voltage is maintained in the arc 18 immediately before the arc spot 17 flows into the electrode groove 15 extending in the circumferential direction of the cylindrical portion 12.
Then, as shown in FIG. 5B, when the arc spot 17 flows into the electrode groove 15 and the arc 18 comes into contact with the groove opening edge portion 15a, the potential between the arc spot 17 and the groove opening edge portion 15a becomes the same. Therefore, the arc 18 cannot maintain the arc voltage and disappears.

Further, even when the arc spot 17 flows into the electrode slit 14 and comes into contact with the inner wall of the electrode slit 14 and the arc comes into contact with the slit edge portion of the electrode slit 14, the arc spot 17 and the slit edge portion of the electrode slit 14 are also contacted. Since the potentials of the arc 18 and the arc 18 are the same, the arc 18 cannot maintain the arc voltage and disappears.
Further, the arc spot 17 generated in the contact plate 11 of the fixed side contact portion 6 also disappears without being able to maintain the arc voltage by the same operation.
In this way, the arc spot 17 generated in the contact plate 11 of the fixed side contact portion 6 and the movable side contact portion 7 disappears in the cylindrical portion 12 of the electrode 10, so that the arc spot 17 can move the movable side energizing shaft 8. It does not have a thermal effect on the bellows 9 that supports the.

Next, the effect of the vacuum valve 1 of the first embodiment will be described.
According to the vacuum valve 1 of the first embodiment, when an arc 18 is generated between the fixed side contact portion 6 and the movable side contact portion 7 when the current is cut off, the fixed side contact portion 6 in which a plurality of electrode slits 14 are formed is formed. And, when a current flows in the circumferential direction through the cylindrical portion 12 of the electrode 10 of the movable side contact portion 7, a longitudinal magnetic field is applied to the arc 18 generated in the fixed side contact portion 6 and the movable side contact portion 7. As a result, the arc 18 is diffused, and the arc voltage between the contact plate 11 of the fixed side contact portion 6 and the movable side contact portion 7 is reduced, so that the breaking property of the arc 18 can be improved.

At the same time, the arc spot 17 generated at the center position of the contact plate 11 of the fixed side contact portion 6 and the movable side contact portion 7 diffuses to the outer circumference of the contact plate 11 and then moves along the outer peripheral surface of the cylindrical portion 12. It flows into the electrode groove 15 extending in the circumferential direction between the pair of electrode slits 14 adjacent to each other in the circumferential direction. Then, when the arc 18 comes into contact with the groove opening edge portion 15a, the potential between the arc spot 17 and the groove opening edge portion 15a becomes the same, so that the arc 18 cannot maintain the arc voltage and disappears.

Therefore, by extinguishing the arc spot 17 at an early stage, the bellows 9 is not thermally affected and the airtightness inside the vacuum insulating container 2 is not impaired. Since it is not necessary to provide a bellows cover or the like between the bellows 9 and the movable contact portion 7 in order to prevent damage to the bellows 9, the cost of parts of the vacuum valve 1 can be reduced and the number of parts can be reduced. Can be planned.
Further, since the electrode groove 15 formed in the cylindrical portion 12 of the electrode 10 has a simple structure extending linearly and formed as a rectangular (square or rectangular) concave portion, the manufacturing cost of the electrode 10 can be reduced. Can be planned.

[Electrode groove of the second to fourth embodiments]
Next, FIGS. 6 to 8 are electrode grooves of the second to fourth embodiments formed on the outer circumference of the cylindrical portion 12 of the electrode 10.
The electrode groove 20 of the second embodiment shown in FIG. 6A is a groove formed by forming the outer peripheral surface of the cylindrical portion 12 as a right-angled triangular concave portion, and the groove opening edge portion 20a on the side into which the arc spot 17 flows has an obtuse angle. It is formed at the corners of.
Similar to the electrode groove 15 of the first embodiment, the electrode groove 20 of the second embodiment linearly extends between a pair of electrode slits 14 adjacent to each other in the circumferential direction, and the inner wall of the electrode slit 14 is formed. It is open with.

Here, in the electrode groove 15 of the first embodiment shown in FIG. 5A, the electric field is likely to be concentrated because the groove opening edge portion 15a on the side where the arc spot 17 flows is formed at a right angle. However, since the groove opening edge 20a of the electrode groove 20 of the second embodiment shown in FIG. 6A is formed at an obtuse angle, the electric field concentration is relaxed. As a result, the arc spot 17 can easily flow into the electrode groove 20 immediately.
Then, as shown in FIG. 6B, when the arc spot 17 flows into the electrode groove 20 and the arc 18 comes into contact with the groove opening edge portion 20a, the potential between the arc spot 17 and the groove opening edge portion 20a becomes the same. Therefore, the arc 18 cannot maintain the arc voltage and disappears.

The groove opening edge portion on the side closer to the contact plate described in the present invention corresponds to the groove opening edge portion 20a.
Therefore, in the vacuum valve 1 in which the electrode groove 20 of the second embodiment is formed on the outer periphery of the cylindrical portion 12 of the electrode, the electric field concentration at the groove opening edge portion 20a of the electrode groove 20 is relaxed and the arc spot 17 becomes the electrode groove 20. Since the flow flows in a short time, the extinction time of the arc 18 can be shortened, and the blocking property of the arc 18 can be further improved.

Next, the electrode groove 21 of the third embodiment shown in FIG. 7A is formed so that the groove opening edge 21a on the side through which the arc spot 17 flows is rounded and protrudes outward.
The groove opening edge 21a having a rounded shape protruding outward has less electric field concentration than the groove opening edges 15a and 20a formed at the corners of the first and second electrode grooves 15 and 20. , The arc spot 17 easily flows into the electrode groove 21 immediately.
Then, as shown in FIG. 7B, when the arc spot 17 flows into the electrode groove 21 and the arc 18 comes into contact with the groove opening edge portion 21a, the potential between the arc spot 17 and the groove opening edge portion 21a becomes the same. Therefore, the arc 18 cannot maintain the arc voltage and disappears.

The groove opening edge portion on the side closer to the contact plate described in the present invention corresponds to the groove opening edge portion 21a.
Therefore, in the vacuum valve 1 in which the electrode groove 21 of the third embodiment is formed on the outer periphery of the cylindrical portion 12 of the electrode, the electric field concentration at the groove opening edge portion 21a of the electrode groove 21 is further relaxed, so that the arc spot 17 is an electrode. It flows into the groove 21 in a short time. As a result, the extinction time of the arc 18 can be shortened, and the blocking property of the arc 18 can be further improved.

Further, the electrode groove 22 of the fourth embodiment shown in FIG. 8A has a shape in which the groove opening edge 22a on the side through which the arc spot 17 flows is rounded and protrudes outward. The groove opening edge portion 22a is formed to have a larger radius of curvature than the groove opening edge portion 21a of the electrode groove 21 of the third embodiment.
Since the electric field concentration is further relaxed in the groove opening edge 22a of the electrode groove 22 of the fourth embodiment having a radius of curvature larger than that of the groove opening edge 21a of the electrode groove 21 of the third embodiment, the arc spot 17 is formed in the electrode groove 22. Will soon flow in easily.

Then, as shown in FIG. 8B, when the arc spot 17 flows into the electrode groove 22 and the arc 18 comes into contact with the groove opening edge portion 22a, the potential between the arc spot 17 and the groove opening edge portion 22a becomes the same. Therefore, the arc 18 cannot maintain the arc voltage and disappears.
The groove opening edge portion on the side closer to the contact plate described in the present invention corresponds to the groove opening edge portion 22a.
Therefore, in the vacuum valve 1 in which the electrode groove 22 of the fourth embodiment is formed on the outer periphery of the cylindrical portion 12 of the electrode, the electric field concentration at the groove opening edge portion 22a of the electrode groove 22 is further relaxed, and the extinction time of the arc 18 is shortened. Will be done. As a result, the breaking property of the arc 18 can be significantly improved.

1 Vacuum valve 2 Vacuum insulated container 3 Fixed side sealing metal fittings 4 Movable side sealing metal fittings 5 Fixed side energizing shaft 6 Fixed side contact part 7 Movable side contact part 8 Movable side energizing shaft 9 Bellows 10 Electrode 11 Contact plate 12 Cylindrical part 13 Bottom 14 Electrode slit 15 Electrode groove 15a, 15b Groove opening edge 16 Contact slit 17 Arc spot 18 Arc 20 Electrode groove 20a Groove opening edge 21 Electrode groove 21a Groove opening edge 22 Electrode groove 22a Groove opening edge

Claims (6)

An electrode having a cylindrical portion and a contact plate for closing an opening on one end side of the cylindrical portion are provided.
A plurality of electrode slits inclined in the axial direction are formed on the peripheral surface of the cylindrical portion so as to be separated from each other in the circumferential direction, and the outer peripheral surface between two adjacent electrode slits of the cylindrical portion is described. A contact for a vacuum valve, characterized in that an arc spot generated in the contact plate flows into the contact plate and an electrode groove is formed to extinguish the arc spot. The contact for a vacuum valve according to claim 1, wherein the electrode groove extends linearly in the circumferential direction of the cylindrical portion. The contact for a vacuum valve according to claim 1 or 2, wherein the electrode groove is formed as a rectangular recess on the outer peripheral surface of the cylindrical portion. The electrode groove is formed as a triangular concave portion on the outer peripheral surface of the cylindrical portion, and the groove opening edge portion on the side of the electrode groove closer to the contact plate is formed at an obtuse-angled corner portion. The contact for a vacuum valve according to claim 1 or 2, wherein the contact is made. The electrode groove is formed as a concave portion on the outer peripheral surface of the cylindrical portion, and the groove opening edge portion on the side closer to the contact plate is formed in a rounded shape so as to project outward. The contact for a vacuum valve according to claim 1 or 2. A vacuum valve according to any one of claims 1 to 5, wherein the vacuum valve contacts are mounted in a vacuum container as a pair of contact portions that can be brought into contact with each other.

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