JP2895449B2 - Vacuum valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a vacuum valve.

[0002]

2. Description of the Related Art A so-called vertical magnetic field electrode, which forms a magnetic field by rotating a current in a circumferential direction, is known as an electrode of a vacuum valve for generating an axial magnetic field between gaps. Also, recently, the present inventors have disclosed in Japanese Patent Application No. 8-141153.
Utilizing a magnetic material to generate an axial magnetic field
Is proposed.

[0003] The invention of Japanese Patent Application No. 8-141531 is illustrated.
Briefly described with reference to 15 , reference numeral 1 denotes an energizing shaft supported at both ends of a cylindrical vacuum vessel (not shown). At the end, an energizing rod 2 and a magnetic body 30 are attached via an energizing plate 13. The contact 4 is disposed facing the tip.

[0004] With this configuration, when a current flows through the current-carrying rod 2, the magnetic flux generated around the current-carrying rod 2 passes through the magnetic body 30, and the direction of the magnetic flux in the gap portion of the magnetic body 30 is changed to the opposite direction (not shown). By being bent toward the magnetic material of the electrode, an axial magnetic flux parallel to the arc is generated between the gaps of the opposed electrodes, thereby stabilizing the arc and improving the breaking performance.

[0005]

In order to reduce the size of the vacuum circuit breaker, it is essential to reduce the size and weight of the vacuum valve. An electrode that generates an axial magnetic field using the above-described magnetic material is a vertical magnetic field using a conventional vertical magnetic field coil.
In being able to greatly simplify the structure compared to electrodes ,
Very effective. However, in the above-described structure, the radial position of the current-carrying rod must be arranged inside the electrode in order to arrange the magnetic body portion outside the current-carrying rod. For this reason, it is difficult to say that an axial magnetic flux sufficient to stabilize the arc can be generated on the entire contact surface . sand
That is , the area where the axial magnetic flux is generated becomes narrow, and it has been difficult to make full use of the contact surface . This has an effect on downsizing the electrode, and there is room for improvement from the viewpoint of reducing the size and weight.

Accordingly, an object of the present invention is to generate a vertical magnetic field in a wide area on a contact with a simpler structure, and to achieve a breaking performance,
An object of the present invention is to provide a small and lightweight vacuum valve having excellent current-carrying performance.

[0007]

According to the first aspect of the present invention, a pair of contacts are provided in a vacuum vessel so as to be able to contact and separate from each other via a pair of conducting shafts for electrically connecting to the outside. In the vacuum valve, between the current-carrying shaft and the contact, a plurality of current-carrying rods that are arranged substantially concentrically with these and whose base end is joined to the current-carrying shaft side, and in a peripheral region of the current-carrying rod,
Inside the circle connecting the centers of all the conducting rods,
Each line is separated by a straight line connecting the center and the center of the current-carrying rod.
One of the two regions and each of the straight lines
A magnetic body portion for generating an axial magnetic field which is at least arranged in a region on the same direction side and which is not present in a region which is point-symmetric with respect to each of the centers of the conducting rods; Having one magnetic body part of the contact and the contact
It is characterized in that the other magnetic part is arranged symmetrically .

Here, the region where the magnetic material exists and the region where the magnetic material does not exist will be described with reference to FIG. That is,
In order to specify the position of the magnetic body with respect to the plurality of conducting rods 2 arranged on the electrode, the center 90 of the electrode, the electrode outer periphery 91, the circle 92 in which all the conducting rods 2 are inscribed, and the circle passing through the centers of all the conducting rods 2 93, draw a line from the electrode center 90 to the conducting rod 2
One of the areas divided by the line inside the circle 93
In the region A, at least a magnetic material is present, and the region A outside the circle 93 and divided by the line described above is electrically connected to the region A.
In the region B symmetrical with respect to the center of the rod 2, the magnetic material is arranged so as not to exist.

Since this magnetic body does not have a closed loop shape, its end functions as a magnetic pole. In addition, since the opposing electrodes have the same structure , each electrode
The magnetic members are symmetrically arranged, and similarly, a magnetic pole is generated at the end of the magnetic member. For this reason , an axial magnetic flux is generated between these magnetic poles, thereby stabilizing the arc and suppressing wear of the contact, thereby improving the breaking performance. Further, since the conventional vertical magnetic field coil is not required, the structure is simple and the weight can be reduced.

The invention according to claim 2 is further characterized in that the magnetic material portion is arranged around the current-carrying rod such that no magnetic material exists in a region outside the circle in which all the current-carrying rods are inscribed. I do.

With this configuration, the current-carrying rod can be placed on the outer peripheral side of the current-carrying shaft, and the magnetic field distribution can be made favorable, so that the arc can be stabilized. According to a third aspect of the present invention, the relative permeability μr of the magnetic material is set to 100
It is characterized by the above.

With this configuration, it is possible to generate an axial magnetic flux sufficient to stabilize the arc between the gaps. The invention described in claim 4 is
Furthermore, regarding the arrangement of the energizing rods,
The arrangement is such that the radius is at least 90% of the radius of the electrode .

That is, in FIG. 1, the radius R1 of the circle in which all the conducting rods 2 arranged concentrically with the conducting shaft are inscribed is
The current-carrying rod 2 is arranged so as to be 90% or more of the radius R2 of the electrode.

[0014] This makes it possible to generate an axial magnetic flux on the surface of the contact and to spread and stabilize the arc, so that the contact can be used effectively and the electrode can be made smaller.

According to a fifth aspect of the present invention, when the number of current-carrying rods is N (number) and the electrode diameter is D [mm], 0.05 D
It is characterized in that the number of conducting rods satisfying <N is provided. As a result, it is possible to suppress a spatial variation in the axial magnetic flux density and cause an arc to be widely spread on the contact surface.

According to a sixth aspect of the present invention, there is provided an energizing rod in which a circumferential distance (W1) between the energizing rod and a magnetic body disposed around the energizing rod is opposite to the energizing rod with respect to the magnetic body. And a magnetic body is disposed so as to be smaller than a circumferential distance (W2).

Here, the relative positional relationship between each energizing rod and the magnetic material will be described with reference to FIG. A magnetic body 3 is disposed between a pair of adjacent energizing rods 2, 2. A circumferential distance (W 1) between a certain energizing rod 2 and a corresponding magnetic body 3 is:
It is arranged so as to be smaller than the circumferential distance (W2) between adjacent energizing rods.

With this arrangement, magnetic flux generated around the current-carrying rod by the current flowing through the nearest current-carrying rod passes through the magnetic body, and the magnetic flux generated around the adjacent current-carrying rod is reversed. The effect of the magnetic flux in the direction can be reduced.

As a result, the strength of the magnetic pole generated at the end of the magnetic body is further increased, and a high axial magnetic flux density can be generated. The invention according to claim 7 is characterized in that a disk-shaped magnetic body is provided at the center of the electrode, and this magnetic body and a magnetic body arranged around the power supply rod are joined to form an integral shape.

With such a configuration, the structure can be simplified. The invention according to claim 8 is characterized in that a hole is provided in a center portion or the like of a disk-shaped magnetic body.

As a result, the axial magnetic flux density generated between the gaps is lower near the center than at the end of the contactor.
When a large current is interrupted, arc concentration on the center of the contact is suppressed, local heating and melting of the contact is prevented, and the interruption performance can be improved.

According to a ninth aspect of the present invention, a cylindrical cover made of stainless steel (SUS) or the like is provided on a side surface portion corresponding to an outer peripheral portion of the electrode of the magnetic material. With such a configuration, a large amount of gas is released when the arc is directly ignited on the magnetic body, but this cover can prevent the release of regas. Therefore, the degree of vacuum in the vacuum valve is sharply reduced, and a sharp decrease in vacuum insulation performance can be prevented.

The invention according to claim 10 is characterized in that an insulating film such as a ceramic coating is applied to the surface of the magnetic material. As a result, the electrical connection between the current-carrying shaft and the magnetic body is cut off, and all the current shunted from the current-carrying shaft to the magnetic body can flow through the current-carrying rod. In addition, since the magnetic flux density generated around the current-carrying rod is proportional to the current flowing in the current-carrying rod, the higher the current flowing in the current-carrying rod, the higher the magnetic flux density can be generated, thereby improving the breaking performance. be able to. Further, it is possible to prevent the arc from directly igniting on the magnetic material portion. As a result, it is possible to prevent the degree of vacuum in the vacuum valve from suddenly decreasing and the vacuum insulation performance from suddenly decreasing.

An eleventh aspect of the present invention is characterized in that a detent for preventing the movement of the magnetic material is provided. When the distance between the conducting rod and the magnetic body increases, the magnetic flux flowing through the magnetic body decreases, and the axial magnetic flux density generated between the gaps decreases.However, by adopting such a configuration, the magnetic body moves, Since it does not rotate, the positional relationship between the current-carrying rod and the magnetic body does not change, and it is possible to prevent the magnetic east density generated between the gaps from decreasing.

The twelfth aspect of the present invention is characterized in that a current carrying plate is provided between the current carrying shaft and the current carrying rod. With this configuration, the current-carrying shaft can be made thinner, so that eddy current generated in the current-carrying shaft can be reduced and the phase lag of the axial magnetic flux with respect to the current can be reduced. Further, since the current-carrying shaft is thin, the weight of the electrode can be further reduced.

According to a thirteenth aspect of the present invention, an electrode plate made of a highly conductive material is provided between the current-carrying shaft and the contact. This makes it possible to make the current flowing through each of the current-carrying rods more uniform, thereby suppressing arc bias. Further, the brazing strength with the current-carrying rod is increased, and an electrode having excellent welding resistance can be realized.

[0027]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 is an exploded perspective view showing an electrode structure according to one embodiment of the present invention. In the drawing, reference numeral 1 denotes one of a pair of energized shafts which are supported oppositely from both ends of a cylindrical vacuum vessel (not shown). At the end of this energized shaft 1,
Four energizing rods 2 are fixedly arranged at substantially equal intervals on a circle substantially concentric with the energizing shaft 1, and a magnetic body 3 is arranged near each energizing rod 2. Here, the relative positional relationship between the conducting rod 2 and the magnetic body 3 is arranged so as to be the same in the circumferential direction. A contact 4 is further fixedly arranged at the tip of the current-carrying rod 2, and this contact 4 faces the other contact similarly configured in the vacuum vessel.

FIG. 4 is a plan view of the electrode excluding the contact 4 viewed from the contact direction. As shown in FIG. 2, when a current flows through the current-carrying rod 2 from the near side as seen in FIG.
, A magnetic flux C is generated, and the magnetic flux C passes through the inside of the magnetic body 3. Since the magnetic body 3 is not in a closed loop, both ends 3a of the magnetic body 3 function as magnetic poles of opposite polarities.

[0029] Here, in the electrode to pair toward energizing rod 2 and the magnetic material having the same shape are arranged similarly, thus each electrode
Are arranged symmetrically, but the current flowing through the current-carrying rod 2 is in the opposite direction at each electrode (one is from the current-carrying shaft side to the contactor side, and the other is from the contactor side to the current-carrying shaft side). , Different magnetic poles are generated. Therefore, an axial magnetic field is generated between the magnetic poles of the opposing magnetic bodies.

As a result, an axial magnetic field can be generated with a simpler structure than a conventional vertical magnetic field coil, and the size and weight of the electrode can be reduced. In addition, since the distance between the outer side surface of the current-carrying rod 2 and the center of the electrode is set to be 90% or more of the electrode radius, an axial magnetic field is generated in almost the entire area of the contact surface, and the contact surface is effectively used. Can be used for

Furthermore, as compared with the conventional vertical magnetic field coil, there is no need to rotate the current in the circumferential direction, so that the current path is very short and the resistance between terminals can be kept low. Have.

FIG. 5 is a graph showing the results of electromagnetic field analysis of the axial magnetic flux density generated between the electrodes when a current is applied to the electrodes configured as described above. As is apparent from the figure, the maximum value of the magnetic flux density appears at four places according to the position of the magnetic pole generated in the magnetic body.

Next, a second embodiment of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 6 is an exploded perspective view, and FIG. 7 is a partial view for explaining the operation. In the second embodiment shown in FIG. 6, a plurality of magnetic members 31 are joined by a disk-shaped magnetic member at the center of the electrode to form an integral shape. In such a configuration, as shown in FIG. 7, the magnetic flux C generated by the current flowing through
1 through the magnetic material tip portion 31a and the magnetic material center portion 31b.
Then, magnetic poles of opposite directions are formed. Therefore, when similar electrodes are combined and used facing each other, the direction of the current flowing through the current-carrying rod 2 is reversed in the same manner as in the embodiment of FIG. 1, so that an axial magnetic flux is generated between the gaps. .

In the case of the present embodiment, since the magnetic body has an integral shape, assemblability is greatly improved. Next, the third aspect of the present invention
Will be described with reference to FIGS. 8 and 9. FIG. FIG. 8A is a perspective view of the magnetic body, and FIG. 8B is a magnetic flux density distribution according to the position of the magnetic body.

In the third embodiment shown in FIG. 8, a hole is provided at the center of the integrated magnetic body as shown in FIG.
For this reason, the distribution of the magnetic flux density in the axial direction generated between the gaps is such that the magnetic flux density at the center is relatively lower than that at the end as shown in FIG.

Therefore, in the distribution of peaks where the magnetic flux density at the center is higher than that at the ends, the arc concentrates at the center of the electrode when a large current is interrupted, and the arc cannot be cut off due to local heating and melting. With the distribution of the magnetic flux density as in the present embodiment, it is possible to spread the arc over the entire contact surface even at the time of interruption of a large current near the interruption limit, and the interruption performance is improved.

FIG. 9 is a perspective view showing an assembled state when the magnetic body of FIG. 8 is used. In the figure, reference numeral 2 denotes a current-carrying rod attached to a current-carrying shaft, and a SUS cylinder 6 is provided so as to cover the side surface of a magnetic body 32 disposed in the vicinity thereof.

It is generally known that a large amount of gas is released when an arc is ignited on a magnetic material. For this reason, when an arc is generated, the degree of vacuum is instantaneously greatly reduced, the dielectric strength is weakened, and the interruption fails. In this embodiment, by covering the side portion of the magnetic body 32 where an arc may be ignited with the SUS cylinder 6, it is possible to prevent the arc from being directly ignited on the magnetic body 32, and to improve the breaking performance. Drop can be prevented.

The same effect can be obtained by applying an insulating material, for example, a ceramic coating to the magnetic body 32. Further, in this case, since the current flowing through the current-carrying shaft has an effect of preventing the current from flowing into the magnetic body, all the current flows through the current-carrying rod. As a result, the magnetic flux density generated around the power supply rod 2 increases, and the axial magnetic flux density generated in the axial direction between the gaps also increases. Therefore, the arc can be further stabilized.

Next, a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 10 shows a perspective view of the energizing shaft 1 and a recess 11 for fitting and fixing a magnetic body.
Is provided. As a result, by changing the position of the magnetic material, the magnetic flux flowing in the magnetic material is reduced by increasing the distance between the current-carrying rod and the magnetic material, and the axial magnetic flux density generated between the gaps can be prevented from decreasing accordingly. .

In this embodiment, the position of the magnetic body can be fixed, so that the decrease in the magnetic flux density is suppressed. However, the same effect can be obtained by providing a similar depression in the contact. FIG.
In the first embodiment, a projection 12 for sandwiching the magnetic body between the current-carrying rod 2 is provided, so that the position of the magnetic body can be fixed. Also in this case, the same effect can be obtained by providing a projection on the contact side.

Next, a fifth embodiment of the present invention will be described with reference to FIG. In the embodiment of FIG. 12, the magnetic body 33 is fixed so as to be wound around the current-carrying rod 2 by shaping a part of the ring as shown in the figure.
Similar effects can be obtained. In this case, in the case of rotating in the circumferential direction, a protrusion as shown in the fourth embodiment may be provided or a concave portion may be provided as necessary.

Next, a sixth embodiment of the present invention will be described with reference to FIGS. In the embodiment shown in FIG. 13, an energizing plate 13 is provided between the energizing shaft 1 and the energizing rod 2. As a result, the current-carrying shaft can be made thinner than the electrode diameter. Further, since the eddy current generated in the energized shaft can be reduced, the phase difference between the current and the magnetic flux can be reduced. Further, the weight of the electrode can be reduced by an amount corresponding to the thinning of the conducting shaft.

FIG. 14 shows a modification of the embodiment shown in FIG. 13, in which an electrode plate 41 made of a highly conductive material is provided between the conducting rod 2 and the contact 4. As a result, the current flowing through each of the current-carrying rods 2 can be made more uniform, and the bias of the arc can be suppressed. Further, the brazing strength between the current-carrying rod 2 and the contact 4 can be increased.

[0045]

As described above, according to the present invention, an arc can be uniformly spread on the contact surface by generating an axial magnetic field with a simple structure, so that the arc processing area is increased and the vacuum is reduced. The shutoff performance of the valve can be improved. In addition, this makes it possible to reduce the size and weight of the vacuum valve having the same interrupting capacity as compared with the related art, and to simplify the structure.

[Brief description of the drawings]

FIG. 1 is a partial view for explaining the present invention.

FIG. 2 is a partial view for explaining the present invention.

FIG. 3 is an exploded perspective view of an electrode on one side of the vacuum valve according to the first embodiment of the present invention.

FIG. 4 is a plan view of an electrode on one side of the vacuum valve according to the first embodiment of the present invention.

FIG. 5 is a graph showing an analysis result of an axial magnetic flux density generated between gaps of the vacuum valve according to the first embodiment of the present invention.

FIG. 6 is an exploded perspective view of an electrode on one side of a vacuum valve according to a second embodiment of the present invention.

FIG. 7 is a view for explaining the operation of the second embodiment of the present invention.

FIG. 8 is a diagram illustrating a magnetic body shape (a) and a magnetic flux density distribution (b) according to a third embodiment of the present invention.

FIG. 9 is a perspective view of a magnetic body and a SUS cylindrical shape according to a third embodiment of the present invention.

FIG. 10 is a perspective view of a conducting shaft according to a fourth embodiment of the present invention.

FIG. 11 is a perspective view of a conducting shaft according to a fourth embodiment of the present invention.

FIG. 12 is a diagram illustrating shapes of a current-carrying rod and a magnetic body according to a fifth embodiment of the present invention.

FIG. 13 is a sectional view of a sixth embodiment of the present invention.

FIG. 14 is a sectional view of a sixth embodiment of the present invention.

FIG. 15 is a perspective view of an example of an electrode using a magnetic material.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Current-carrying shaft 2 ... Current-carrying rod 3 ... Magnetic body 4 ... Contact 5 ... Magnetic east density distribution 6 ... SU
S cylinder 13: energizing plate 41: electrode plate 90: electrode center 91: electrode outer periphery 92: circle in which the energizing rod is inscribed 93: circle passing through the center of the energizing rod

Continuing on the front page (72) Inventor Kenji Watanabe 1 Toshiba-cho, Fuchu-shi, Tokyo, Japan Inside the Toshiba Fuchu Plant, Inc. 72) Inventor Yoshimitsu Niwa 1 Toshiba-cho, Fuchu-shi, Tokyo Tokyo, Japan Inside the Fuchu Plant, Toshiba Corporation (72) Inventor Mitaka 1 Toshiba-cho, Fuchu-shi, Tokyo Tokyo Inside the Fuchu Plant, Toshiba Corporation (72) Hirotsuka 1 Toshiba-cho, Fuchu-shi, Tokyo Toshiba Fuchu Factory (72) Inventor Keisei Seki 1 Toshiba-cho, Fuchu-shi, Tokyo Toshiba Fuchu Factory (72) Inventor Takashi Kusano Toshiba Fuchu-shi, Tokyo 1-cho, Toshiba Corporation Fuchu Plant (56) References: Japanese Utility Model Application Sho 55-173039 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) H01H 33/66

Claims (13)

(57) [Claims] 1. A vacuum valve comprising a pair of contacts provided in a vacuum vessel so as to be capable of coming and going through a pair of current supply shafts for electrically connecting to the outside, wherein the contact between the current supply shaft and the contact is provided. between these and arranged substantially concentrically, and a plurality of energizing rod proximal end is joined to the energizing shaft side, in the peripheral region of the current bar, among all the energizing rod
Inside the circle connecting the hearts, between the center of the electrode and the conducting rod
In each of the two regions separated by a straight line connecting the heart
Either side and in the same direction as viewed from each of the straight lines
At least disposed in the area, have a magnetic body for generating an axial magnetic field so as not present in the region to become the region and point symmetry each <br/> about the center of the current bar
And one magnetic part of the contact and the other of the contact
A vacuum valve wherein the magnetic parts are arranged symmetrically . 2. A vacuum according to claim 1, wherein a magnetic portion is arranged around the current-carrying rod so that no magnetic material is present in a region outside a circle in which the current-carrying rods are all inscribed. valve. 3. The relative magnetic permeability (μr) of the magnetic material is 100
Vacuum valve according to claim 1 or claim 2, characterized in that at least. 4. The vacuum valve according to claim 2, wherein the energizing rods are all arranged such that the radius of a circle inscribed therein is 90% or more of the radius of the electrode. 5. The number of the current bar N (present), when the electrode diameter is D (mm), 0.05 D <of claims 1 to 4, characterized in that set to be N The vacuum valve according to any one of the above. 6. A current-carrying rod, which is located on a side opposite to the current-carrying rod with respect to the magnetic body, has a circumferential distance (W1) between the current-carrying rod and a magnetic body disposed around the current-carrying rod and the magnetic body. The vacuum valve according to any one of claims 1 to 5, wherein the distance is smaller than a circumferential distance (W2). 7. A vacuum valve according to any one of claims 1 to 6, characterized in that the bound pair shape arranged disc-shaped magnetic body the magnetic body electrode center. 8. The vacuum valve according to claim 7, wherein a hole is provided in a disk portion of the magnetic body. 9. A vacuum valve according to any one of claims 1 to 8, characterized in that a cover side a cylindrical of the magnetic material. Vacuum valve according to any one of claims 1 to 9, characterized in that subjected to coating - 10. On the surface of the magnetic insulation co. 11. The vacuum valve according to any one of claims 1 to 10, characterized in that a detent to prevent movement of the magnetic body. 12. A power supply plate comprising a high conductivity material is provided between the power supply shaft and the power supply rod.
A vacuum valve according to claim 11. 13. The vacuum valve according to any one of claims 1 to 12, characterized by comprising an electrode plate formed of a high conductivity material between the contacts and the current-carrying rod.