JP3231595B2 - 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 Conventionally, a method of extinguishing an arc by applying a magnetic field in parallel with a vacuum arc generated between electrodes has been adopted to improve the shutoff performance of a vacuum valve.

[0003] As such a vacuum valve, there is a vertical magnetic field type vacuum valve, and several kinds of electrode structures have been implemented and proposed.
The description will be made based on the structure of the vertical magnetic field electrode shown in FIG. 7 which is a vertical sectional view of the electrode disclosed in Japanese Patent Application Laid-Open No. 54-12622.

Although FIG. 7 shows a movable electrode, the fixed electrode has the same structure.

In FIG. 7, a circular counterbore 11a is formed at the tip of a movable-side energizing shaft 11 made of a copper bar. The counterbore 11a has a substantially T-shaped vertical cross section. In a plan view (not shown), a shaft portion 14a protruding from the lower portion of the annular stainless steel reinforcing member 14 is fitted and brazed.

An annular shaft 15a made of copper material and projecting from the center of a coil electrode 15 described below is inserted into the outer periphery of the shaft 14a. It is brazed to.

In this coil electrode 15, three arm portions 15b from the outer periphery of a shaft portion 15a are radially spaced by 120 ° as shown in FIG. 8 showing a cross sectional view of FIG. In the plan view shown in FIG. 8, a base end of an arc-shaped coil portion 15c is brazed to the distal ends of these arm portions 15b. A through hole 15d is formed at the tip of each of the coil portions 15c in the axial direction as shown in FIG.

[0008] These through-holes 15d, substantially T-shaped in FIG. 7, the shaft portion of the circular copper material made of connectors 7 B is inserted in the plan view shown in FIG. 8, the distal end of the coil portion 15c It is brazed to.

On the upper end surface of the reinforcing member 14, an electrode plate 13 formed in a disk shape from a copper plate and having grooves formed radially from the center to the outer periphery is placed. The electrode plate 13 is brazed to the surface of the reinforcing member 14 and the connector 7b.

A contact 16 is joined to the upper surface of the electrode plate 13 by brazing. The contact 16 is formed in a disc shape from a copper-chromium alloy, has a groove formed radially from the center to the outer periphery in the same manner as the electrode plate 13, and the outer peripheral surface is chamfered in an arc shape.

In the electrode of the vacuum valve configured as described above, for example, most of the current flowing from the movable-side conducting shaft 11 to the contact 16 is diverted from the shaft 15a of the coil electrode 15 to a plurality of arms 15b. Flows to the coil 15c at the tip of the arm 15b. Note that some currents are supplied by reinforcing members with high specific resistance.
After 14, it flows into the electrode plate 13.

The current flowing into the coil portions 15c flows into the inside of the electrode plate 13 from the connector 7b at the tip of each coil portion 15c, through the back surface of the outer periphery of the electrode plate 13, and
It flows out from the surface of 13 to the contact 16.

The current flowing to the contact 16 is
Flows into the contact of the fixed-side electrode (not shown) in contact with the surface of the contact 16, and then flows out to the fixed-side energized shaft via the electrode plate of this fixed-side electrode, the connector, and the coil electrode.

In the vacuum valve having the movable side electrode and the fixed side electrode incorporated therein, when the movable side electrode is separated from the fixed side electrode and an arc is generated between both electrodes, the arc current causes An axial magnetic field, that is, a so-called vertical magnetic field, is generated between the two electrodes 15c along with the current flowing through each coil portion 15c of each coil electrode 15.

The magnetic flux density of the longitudinal magnetic field is maximum at the axial center of the electrode, and decreases toward the outer periphery of the electrode, forming a substantially sinusoidal curve. The arc generated between the electrodes that generate such a vertical magnetic field is not locally concentrated on the surfaces of the two electrodes, but spreads over the entirety and uniformly, as compared with an electrode that does not generate a vertical magnetic field. Therefore, melting of the contact surface due to local concentration can be prevented, a rise in metal vapor pressure caused by the melting can be prevented, an increase in arc can be suppressed, and a breaking performance can be improved.

[0016]

However, in the vacuum valve constructed as described above, when the breaking current further increases, the arc generated at the center of the contact having a high magnetic flux density increases, and the breaking performance is further improved. It is an obstacle in planning.

It is considered that the arc concentrates at the central portion of the contact due to the effect of the pinch force due to the self-current acting on the arc and the characteristic that the arc concentrates in a strong magnetic field region. Experiments have also confirmed that the latter effect of concentrating on a strong magnetic field is greater than the effect of force.

For this reason, a method of further increasing the magnetic flux density between the electrodes to improve the interruption performance is conceivable. However, according to the experimental results of the inventors, when the interruption current increases, the arc also concentrates on the central portion.

Then, the current density at the center of the electrode where the arc is concentrated increases, and the surface of the contact is locally melted by the heat input. If the melting amount exceeds the critical value, the recovery of insulation after current interruption may be delayed due to the metal vapor generated from this portion and floating between the electrodes, and the arc may not be interrupted.

As a result, when the number of arcs further increases, the number of cathode spots merely increases on the cathode side, but on the anode side, the anode of the arc merged by the pinch effect is formed.
Therefore, an object of the present invention is to provide a vacuum valve which can prevent concentration of an arc at the center of an electrode and can further improve cutoff performance.

[0021]

According to a first aspect of the present invention, there is provided a vacuum valve, wherein a tip of a fixed-side energizing shaft penetrating through one axis of an insulated cylindrical container and another axis of the insulated cylindrical container. Electrodes are provided at the tips of the movable-side energized shafts penetrating through, and in the vacuum valve in which contacts are brazed to the tips of these electrodes,
The permanent magnet is housed in the axial direction with the same pole facing the tip of the fixed-side energized shaft and the tip of the movable-side energized shaft, and the electrode is
The coil electrode is a left-hand wound coil electrode when viewed from the contact side.
The opposite side of the permanent magnet is an S pole, and the right-handed
It is characterized in that the il electrode is an N pole . Claim 2
The vacuum valve of the invention described above is mounted on the shaft center on one side of the insulating cylindrical container.
In addition to the tip of the fixed-side conducting shaft
Axial magnetic force is applied to the tip of the movable side energized shaft
The electrodes that generate the field are provided, and the tips of these electrodes are connected.
In the vacuum valve where the point is brazed,
A permanent magnet has the same pole at the end of the shaft and the end of the movable side conducting shaft.
Are housed in the axial direction facing each other, and the electrode is
And the top of the slit when viewed from the side
The opposite side of the permanent magnet of the electrode is an S pole,
The electrode of the beam is an N pole.

[0022]

A vacuum valve according to a third aspect of the present invention is provided so as to penetrate a distal end of a fixed-side energizing shaft penetrating one axial center of the insulating cylindrical container and another axial center of the insulating cylindrical container. Coil electrodes are provided at the ends of the movable-side energized shafts, and the coil electrodes are composed of an inner coil and an outer coil. The winding direction of the outer coil on the side is the same, and the winding direction of the inner coil on the fixed side and the inner coil on the movable side are reversed.

Further, the vacuum valve of the present invention according to claim 4, the contact material, characterized in that the arc voltage of the central portion is small arc voltage of the outer periphery at the large.

Furthermore, the vacuum valve of the present invention according to claim 5, characterized in that the formation of the through-hole in the center of the contact.

According to the first and second aspects of the present invention, by means of the permanent magnets having the same poles disposed opposite to each other, the central portion between the electrodes has a lateral portion perpendicular to the axial direction. A magnetic field is generated, and the transverse magnetic field drives the arc at the center of the electrode surface toward the outer periphery.
The arc driven in the outer circumferential direction is
Axial magnetic field formed by the current flowing through the tip electrode
Extinguished by the world.

According to the third aspect of the present invention,
An arc current flowing through the inner coil generates a transverse magnetic field in the central portion between the electrodes in a direction perpendicular to the axial direction, and the transverse magnetic field drives the arc at the central portion of the electrode surface in the outer peripheral direction.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the vacuum valve of the present invention will be described below with reference to the drawings. FIG. 1 is a partial longitudinal sectional view showing a first embodiment of a vacuum valve according to the present invention, and corresponds to FIG. 7 shown in the prior art.

FIG. 1 differs greatly from FIG. 1 shown in the prior art in that permanent magnets are embedded in the electrode-side ends of the fixed-side energized shaft 1A and the movable-side energized shaft 1B. Others are almost the same as those in FIG.

That is, after the fixed-side end plate is brazed to the lower end of the fixed-side current-carrying shaft 1A whose upper end is hermetically inserted through the fixed-side end plate of a vacuum insulating container (not shown), the permanent magnet 5A
Is inserted and fixed in the inside of the tube with the N-pole side facing down.

The shaft 2a1 of the coil electrode 2A is inserted and brazed to the outer periphery of the lower end of the fixed-side energized shaft 1A.
A central portion of a disk-shaped reinforcing plate 6A made of stainless steel is brazed to the lower end surface of the fixed-side energized shaft 1A on the same axis.

[0032] coil electrode 2A, as shown in FIG. 2 showing a partial plane view of FIG. 1, the arm portion 1 from the outer periphery of the shaft portion 2a1
Radially formed at intervals of 20 °. The tips of these arms are continuous with one side of the arc-shaped coil portion 2b1. A connector 7A is inserted and brazed at the tip of the coil portion 2b1.

An electrode plate 3A made of a copper plate is brazed to the distal end surface of each coil portion 2b1, and the distal end surface of the connector 7A is brazed to the back surface of the electrode plate 3A. A contact 4A is brazed to a further end surface of the electrode plate 3A. A through hole 4a1 is formed at the center of the contact 4A. The outer surface side of the through hole 4a1 is chamfered in an arc shape.

Similarly, after the movable side end plate of the vacuum insulating container (not shown) is brazed to the upper end of the movable side energized shaft 1B having an intermediate portion airtightly provided through a bellows, the movable side end plate is brazed. permanent magnets 5 B is inserted in the N-pole side to the upper inside of the tubular, it is fixed.

On the outer periphery of the upper end of the movable-side conducting shaft 1B, a coil electrode 2 symmetrically formed in the same shape as the coil electrode 2A is formed.
The shaft portion 2a2 of B is inserted and brazed. A disk-shaped reinforcing plate 6B made of stainless steel is brazed to the upper end surface of the movable-side energized shaft 1B on the same axis.

The coil electrode 2B shown in FIG.
Similar to FIG. 2 showing a planar rear view of A, the arm portion from the outer periphery of the shaft portion 2a2 is formed radially and in 120 ° intervals. The tips of these arms are continuous with one side of the arc-shaped coil portion 2b2. The connector 7A shown in FIG. 2 is inserted and brazed to the tip of the coil portion 2b2.

An electrode plate 3B made of a copper plate is brazed to the distal end surface of each coil portion 2b2, and the distal end surface of a connector 7A is brazed to the back surface of the electrode plate 3B. A contact 4B is brazed to a further end surface of the electrode plate 3B. A through hole 4a2 is also formed at the center of the contact 4B.

In the electrode of the vacuum valve configured as described above, for example, most of the current flowing from the movable-side energized shaft 1B to the contact 4B passes through a plurality of arms from the shaft 2a2 of the coil electrode 2B. It flows to the coil 2b2 at the tip of the arm. A part of the current is supplied to the reinforcing plate 6 having a high specific resistance.
After passing through B, it flows into the electrode plate 3B.

The current flowing into the coil portion flows from the connector 7B at the tip of each coil portion to the electrode plate 3B via the back surface of the outer periphery of the electrode plate 3B, and from the surface of the electrode plate 3B to the contact 4B. leak.

The current flowing out to the contact 4B flows from the contact 4B to the contact 4A of the fixed electrode in contact with the surface of the contact 4B. Hereinafter, the electrode plate 3A of the fixed electrode, the connector 7A and the coil Via the electrode 2A, the fixed-side energized shaft 1
Outflow to A.

When the energized electrode is opened,
The arc generated at the center between the contacts is caused by the permanent magnets 5A, 5A.
B is driven in the outer circumferential direction by the magnetic flux in the direction indicated by arrow A in FIGS.

Here, when a current flows from the movable electrode to the fixed electrode, for example, the combined magnetic field of the permanent magnet indicated by the arrow A indicates the contact on the anode side due to the vertical magnetic flux in the direction indicated by the arrow B. Move in the direction of 4B. Similarly, when the current is reversed, the current moves in the direction of the contact 4A on the anode side due to the reversal of the polarity of the contact and the reversal of the vertical magnetic flux. Further, since the through holes 4a1 and 4a2 are formed in the central portions of the contacts 4A and 4B, discharge at the central portions can be prevented.

The arc driven in the outer peripheral direction is extinguished by the axial magnetic flux generated by the coil portions 2b1 and 2b2 of the coil electrodes 2A and 2B. Therefore,
In addition to preventing arc concentration on the center of the electrode,
Since the arc concentrated on the anode side can be driven,
Arc extinguishing performance can be improved, and the breaking capacity can be further increased.

In the above example, the contacts 4A, 4B
Is to increase the arc voltage at the center and decrease the arc voltage at the outer periphery by setting the ratio of the content of copper and chromium at the center to, for example, 75:25 and the ratio of the outer periphery to 50:50. Thus, the arc extinguishing performance may be further improved.
The polarity of the permanent magnets 5A and 5B on the opposite side is set to the N pole. However, when the winding direction of the coil portions of the coil electrodes 2A and 2B is opposite to the left in FIG. 2, the S pole may be set.

Next, FIG. 4 shows a second embodiment of the vacuum valve of the present invention.
2 is a partial plan view showing an embodiment of the present invention, corresponding to FIG.
It is a figure corresponding to No. 3 . FIG. 5 is a diagram showing a movable-side coil electrode viewed from above (i.e., viewed from the movable-side energized shaft side) from the cross section of the movable-side electrode in FIG. 1.

4 and 5, the difference from the coil electrodes 2A and 2B shown in FIGS. 1 and 2 is that the coil portion is doubled. That is, in FIG. 4 showing the fixed side coil electrode, a small inner coil portion is formed from the tip of the arm portion formed radially from the outer periphery of the shaft portion 12a1.
12c1 is formed counterclockwise.

At the tips of these inner coil portions 12c1,
The outer arm portions are formed radially, and the same outer coil portion as the coil portion 15c shown in FIG.
12b1 is formed counterclockwise.

On the other hand, in FIG. 5 showing the movable-side coil electrode as viewed from the movable-side energized shaft side, the small inner coil portion 12c2 starts from the tip of the arm portion formed radially from the outer periphery of the shaft portion 12a2. Are formed in a clockwise direction opposite to the fixed side.

At the tips of these inner coil portions 12c2,
The outer arm portions are formed radially, and the outer coil portion 12b2 is formed counterclockwise from the distal ends of these outer arm portions, similarly to the fixed side.

In the vacuum valve having the coil electrodes formed as described above, the directions of the magnetic fluxes generated by the arc current flowing through the fixed inner coil portion 12c1 and the movable inner coil portion 12c2 are opposite to each other. Accordingly, similarly to the vacuum valve incorporating the permanent magnets 5A and 5B shown in FIG. 1, the arc at the center is driven in the outer peripheral direction by the magnetic flux at the center of the contact which is orthogonal to the axial direction.

In this case, the permanent magnet 5 shown in FIG.
Although the magnetic flux generated at A and 5B is constant irrespective of the breaking current, a transverse magnetic field proportional to the breaking current can be generated, so that the breaking capacity can be further increased.

FIG. 6 shows a third embodiment of the vacuum valve of the present invention.
FIG. 4 is a view showing an embodiment of the present invention, and corresponds to claim 2 , and the movable electrode shows a vertical sectional view as in FIG. 1. In FIG. 6, FIG.
The difference is that cup electrodes 8A and 8B having a U-shaped cross section are used instead of the coil electrodes 2A and 2B.

That is, at the lower end of the fixed-side energized shaft 1A,
A cup electrode 8A having a plurality of slits 8a formed obliquely on the outer periphery is brazed. Similarly, a cup electrode 8B manufactured symmetrically with the fixed-side cup electrode 1A is also provided at the upper end of the movable-side conducting shaft 1B. Brazed.

In the vacuum valve incorporating the electrode configured as described above, the permanent magnet 5A is provided at the center of the electrode against the vertical magnetic field generated by the current flowing through the outer cylinder of the upper and lower cup electrodes 8A and 8B. , 5B, the arc generated at the center by the transverse magnetic field formed by the magnetic fluxes of the opposite directions is driven in the outer circumferential direction of the electrode. It is possible to prevent a decrease in the cutoff characteristics due to the increase. In the above embodiment, the polarity on the opposite side of the permanent magnets 5A and 5B is set to the N pole. However, when the inclination of the slits 8a and 8b of the cup electrodes 8A and 8B is reversed, the polarity may be set to the S pole.

[0055]

As described above, according to the first and second aspects of the present invention, the tip of the fixed-side current-carrying shaft penetrating the shaft center on one side of the insulated cylindrical container and the other shaft of the insulated cylindrical container. Electrodes are provided at the ends of the movable-side energized shafts penetrating the core, and in a vacuum valve in which contacts are brazed to the ends of these electrodes, a permanent The magnet is housed in the axial direction with the same poles facing each other, and the electrode is
Pole and the left-handed coil electrode as viewed from the contact side.
The opposite side of the permanent magnet is an S pole, and the coil electrode is clockwise wound
Is the N pole, or the electrode is a cup electrode, and the contact is
With the slit facing upward as viewed from the side
The opposite side of the electrode to the permanent magnet is defined as the south pole, and
The serial electrodes than is N pole, by said permanent magnet, by generating a transverse magnetic field in the axial direction and perpendicular direction in the central portion between the electrodes, electrostatic drives the arc of the central portion of the electrode surface toward the outer periphery <br/> prevent arc concentration to the electrode central portion is driven in the outer circumferential direction
The arc that is applied to the coil electrode or the cup electrode
By the axial longitudinal magnetic field formed by the flowing current
By extinguishing the arc, it is possible to obtain a vacuum valve capable of further improving the shutoff performance.

According to the third aspect of the present invention, the fixed-side energizing shaft penetrating the shaft on one side of the insulating cylindrical container and the shaft center on the other side of the insulating cylindrical container. In a vacuum valve in which coil electrodes are provided at the ends of the movable-side energized shafts and the contacts are brazed to the ends of these coil electrodes, the coil electrodes are configured with an inner coil and an outer coil, and the fixed outer coil and the movable The winding direction of the outer coil is the same,
By reversing the winding direction of the inner coil on the fixed side and the inner coil on the movable side, an arc current flowing through the inner coil generates a transverse magnetic field in a central portion between the electrodes in a direction orthogonal to the axial direction. Since the arc at the center of the surface was driven in the outer peripheral direction, the concentration of the arc at the center of the electrode was prevented,
A vacuum valve capable of further improving the shutoff performance can be obtained.

[Brief description of the drawings]

FIG. 1 is a partial longitudinal sectional view showing a first embodiment of a vacuum valve of the present invention.

FIG. 2 is a partial plan view of FIG. 1;

FIG. 3 is an explanatory view showing the operation of the first embodiment of the vacuum valve of the present invention.

FIG. 4 is a partial plan view showing a second embodiment of the vacuum valve of the present invention.

FIG. 5 is a partial plan view showing a second embodiment of the vacuum valve of the present invention, which is different from FIG. 4;

FIG. 6 is a partial longitudinal sectional view showing a third embodiment of the vacuum valve of the present invention.

FIG. 7 is a partial vertical sectional view showing an example of a conventional vacuum valve.

FIG. 8 is a partial plan view of FIG. 7;

[Explanation of symbols]

1A: fixed-side energized shaft, 1B: movable-side energized shaft, 2A, 2B
... Coil electrodes, 3A, 3B ... Electrode plates, 4A, 4B ... Contacts, 4a1, 4a2 ... Through holes, 5A, 4B ... Permanent magnets,
6A, 6B: reinforcing plate, 7A, 7B: connector, 8A, 8B
... Cup electrode.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenji Watanabe 1 Toshiba-cho, Fuchu-shi, Tokyo Inside the Toshiba Fuchu Plant Co., Ltd. (72) Inventor Eiji Kaneko 1-Toshiba-cho, Fuchu-shi, Tokyo Toshiba Fuchu Plant (72) Inventor Hiromichi Somei 1 Toshiba-cho, Fuchu-shi, Tokyo Inside the Toshiba Fuchu Plant (72) Inventor Mitaka Homma 1-Toshiba-cho, Fuchu-shi, Tokyo Inside the Fuchu Plant, Toshiba (56) References JP-A-2-278627 (JP, A) JP-A-7-85754 (JP, A) JP-A-60-146419 (JP, A) JP-A-7-37472 (JP, A) JP-A-5-114338 (JP, A) JP-A-57-76713 (JP, A) JP-A-57-189420 (JP, A) JP-A-56-84829 (JP, A) JP-A-58-79927 (JP, U) 55-173040 (JP, U) 56-42905 (JP, Y1) (58 ) investigated the field (Int.Cl. ^7, DB name) H01H 33/66

Claims (5)

(57) [Claims] 1. An axial direction is provided between a tip of a fixed-side energizing shaft penetrating through one axis of the insulating cylindrical container and a tip of a movable-side energizing shaft penetrating through the other axis of the insulating cylindrical container. Electrodes for generating a magnetic field are provided, and in a vacuum valve in which contacts are brazed to the tips of these electrodes, a permanent magnet is provided with the same pole facing the tip of the fixed-side energizing shaft and the tip of the movable-side energizing shaft. housed axially Te, the electrode and the coil electrode, the contact side
Facing the permanent magnet of the coil electrode wound leftward
A vacuum valve, characterized in that an S pole is on the side and the right-handed coil electrode is an N pole . 2. An insulated cylindrical container having a shaft center penetrated on one side.
Between the tip of the fixed-side energized shaft and the axis of the other side of the insulating cylindrical container
Generates an axial magnetic field at the tip of the movable energized shaft
Electrodes are provided and the contacts are brazed to the tips of these electrodes.
In the vacuum valve, the tip of the fixed-side energized shaft and
At the tip of the movable side energizing shaft, a permanent magnet
The electrode is a cup electrode, the contact is on the side, and when viewed from the side, the direction of the slit is right-upward, the opposite side of the permanent magnet is the south pole, and the right-downward electrode is the N-pole. A vacuum valve characterized by being poled. 3. A coil electrode is provided at a tip of a fixed-side energized shaft penetrating through one axis of the insulated cylindrical container and a tip of a movable-side energized shaft penetrated through the other axis of the insulated cylindrical container. In a vacuum valve provided with a contact point brazed to the tip of the coil electrode, the coil electrode is composed of an inner coil and an outer coil, and the winding direction of the fixed outer coil and the movable outer coil is the same. A vacuum valve wherein the winding directions of the fixed inner coil and the movable inner coil are reversed. Wherein said contact material is a vacuum valve according to any one of claims 1 to 3, characterized in that the arc voltage of the central portion is small arc voltage of the outer periphery at the large. 5. A vacuum valve according to any one of claims 1 to 4, characterized in that the formation of the through-hole in the center of the contact.