JPH11329173A - Vacuum valve - Google Patents

Abstract

(57) [Summary] An arc generated at the time of current interruption is widely distributed between contacts so that excellent interruption performance can be obtained by effectively utilizing the entire surface of the contacts. SOLUTION: A fixed electrode rod 2 is provided inside a vacuum vessel 1.
And disk-shaped contacts 4 and 4 which are attached to the distal end of the movable electrode rod 3 so as to be substantially coaxially opposed to each other, and come into contact with and separate from each other.
On the periphery of the surface, the inclination angle with respect to the other facing surface 40, 40,
The tapered portions 41, 41 which are continuously changed in the circumferential direction with one side in the radial direction being the maximum and the other side being the minimum are formed. Such contacts 4 and 4 are connected to the bus-side conductor 6 outside the vacuum vessel 1.
In addition, the tapered portions 41 are attached to the fixed electrode rod 2 and the movable electrode rod 3 with the inclination angle of the tapered portions 41, 41 facing the lead-out side of the load-side conductor 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum valve for a vacuum circuit breaker for opening and closing a current by bringing a fixed electrode and a movable electrode into and out of a vacuum vessel.

[0002]

2. Description of the Related Art A vacuum valve includes a vacuum vessel in which both sides of a cylindrical body made of an insulating material are closed by a cover plate and the inside thereof is evacuated, and a vacuum vessel which penetrates each of the cover plates into the vacuum vessel. An extended rod-shaped fixed electrode rod and a movable electrode rod, and a disk-shaped contact attached to the ends thereof so as to be substantially coaxially opposed to each other, and the fixed electrode is extended outside the vacuum vessel. The electrode rod and the movable electrode rod are connected to the main circuit conductor, and the operation of the movable electrode rod brings the contact on the movable electrode side into and away from the contact on the fixed electrode side to open and close the main circuit current.

[0003] Such a vacuum valve can open and close a large current because the main circuit current is opened and closed in a high vacuum where a large dielectric strength can be obtained. Arcing has the advantage of reducing arcs inevitably generated between contacts when current is interrupted, but in order to perform a more stable switching operation, the arc generation behavior between the contacts is controlled. However, it is important to diffuse the arc over the entire surface of the contact.

In order to achieve such an arc diffusion,
For example, as disclosed in JP-A-50-61671, JP-A-63-96243, etc., the contact with the other of the disc-shaped contacts attached to the tips of the fixed electrode rod and the movable electrode rod is described. It is effective to provide a tapered portion on the peripheral portion on the opposite side.

FIG. 8 is a sectional side view showing the structure of a main part of a conventional vacuum valve disclosed in the above-mentioned Japanese Patent Application Laid-Open Nos. 50-61671 and 63-96243, and FIG. FIG. 10 is an enlarged view of the vicinity of the contact, and FIG. 10 is a plan view taken along line XX of FIG.

As shown in FIG. 8, inside a vacuum vessel 1, a fixed electrode rod 2 in the form of a round bar is fixedly supported through one end wall of the vacuum vessel 1, and a bellows 30 is attached to the other end wall. A movable electrode rod 3 in the form of a round bar movably supported via a pair is disposed with its ends facing each other, and at these ends, disk-shaped contacts 5 and 5 are coaxially arranged. Each is fixed so as to face each other.

[0007] Fixed electrode rod 2 protruding outside vacuum vessel 1
The other side is connected to the bus-side conductor 6. The other side of the movable electrode rod 3 protruding outside the vacuum vessel 1 is connected to an operation mechanism (not shown) via an operation rod 31 which is coaxially connected, and a load-side conductor facing the side. 7 is connected via a flexible conductor 8.

As shown in FIG. 9, the contacts 5, 5 attached to the fixed electrode rod 2 and the movable electrode rod 3 are opposed to each other at the center on the side opposite to the other, and the movable electrode rod 3 moves (described later). Opposing surfaces 50, 50 which come into contact with and separate from each other.
It has 1,51. These tapered portions 51, 51 are formed at a predetermined inclination angle θ with respect to the facing surfaces 50, 50 in a direction to reduce the thickness on the outer peripheral side.

In the conventional vacuum valve configured as described above, the movable electrode rod 3 is moved in the axial direction by the operating force applied from the operating mechanism (not shown) via the operating rod 31, and the movable electrode rod 3 is moved. The contacts 5 and 5 fixed to the fixed electrode rod 2 and the fixed electrode rod 2 come and go. These contacts 5,5
Are in contact with each other, the fixed electrode rod 2, the contact 5,
5, bus-side conductor 6 via movable electrode rod 3 and flexible conductor 8
Main circuit current flows through the load side conductor 7 from the
Is separated, the main circuit current is reliably cut off between the opposed contacts 5 and 5 while maintaining a predetermined insulation distance under a high vacuum inside the vacuum vessel 1. As described above, the main circuit current is opened and closed in accordance with the contact and separation of the contacts 5 and 5 due to the movement of the movable electrode bar 3.

In such an operation, when the contacts 5, 5 are separated from each other due to current interruption, an arc is generated between them, and this arc is formed on the periphery of the contacts 5, 5 as described above. By the action of the tapered portions 51, 51, the opposing surfaces 50,
It shows the occurrence behavior that spreads over the entire surface of the contacts 5, 5 including the tapered portions 51, 51 without concentrating on 50, and by appropriately setting the inclination angle θ of the tapered portions 51, 51,
It is said that a desirable arc generation behavior uniformly diffused within the diameters of the contacts 5, 5 is obtained, and that good breaking performance is obtained by effectively utilizing the entire surfaces of the contacts 5, 5.

[0011]

However, in such a vacuum valve, the fixed electrode rod 2 and the movable electrode rod 3
In many cases, the main circuit conductors (the busbar-side conductor 6 and the load-side conductor 7) connected to each other are drawn to the same side outside the vacuum vessel 1 as shown in FIG. When such a conductor arrangement is adopted, a “U” -shaped current path is formed from the busbar-side conductor 6 to the load-side conductor 7 via the fixed electrode rod 2, the movable electrode rod 3 and the flexible conductor 8. As a result, the electromagnetic force generated by the current flowing through the current path acts on the arc generated between the contacts 5 and 5 at the time of the above-described breaking operation, and the arc is generated on the drawing side of the bus-side conductor 6 and the load-side conductor 7. The phenomenon that is blown out in the opposite direction occurs,
The actual distribution of the arc in the plane of the contact 5 includes a central facing surface 50, as shown by hatching in FIG. 10, and has a distribution that is biased toward the side opposite to the lead-out side of the conductor,
There was a disadvantage that the entire surface of the contact 5 could not be used effectively and a predetermined breaking performance could not be obtained.

The present invention has been made in view of the above circumstances, and controls the behavior of an arc generated between contacts at the time of current interruption in consideration of an electromagnetic force acting from a main circuit side.
An arc widely distributed between the contacts can be generated,
An object of the present invention is to provide a vacuum valve having excellent shutoff performance.

[0013]

According to a first aspect of the present invention, there is provided a vacuum valve in which the inclination of a tapered portion of a peripheral edge of a contact point attached to each of the fixed electrode and the movable electrode is maximized on one side in the radial direction. The side is minimized and continuously changed in the circumferential direction.

In the present invention, when a contact is attached to each of the fixed electrode rod and the movable electrode rod, the separation distance between the tapered portions on the periphery becomes large or small according to the magnitude of the inclination angle. Is biased toward the side where the inclination angle is small, offset by the bias of the arc distribution due to the action of the electromagnetic force, and a desirable arc distribution state widely diffused over the entire surface of the contact is obtained.

According to a second aspect of the present invention, there is provided a vacuum valve, wherein an electrode rod constituting a fixed electrode and / or a movable electrode and a contact are provided.
Each of the contacts is provided with a coil electrode for generating an axial magnetic field in accordance with the flow of the arc current.

In the present invention, by the action of the magnetic field generated by the coil electrode, the arc generated when the current is interrupted is confined within the diameter of the contact and is evenly distributed within this range to obtain good interrupting performance.

A vacuum valve according to a third aspect of the present invention is provided with a slit groove having an opening at the outer peripheral edge and extending toward the center at a plurality of positions in the circumferential direction of the contact.

In the present invention, each of the disc-shaped contacts is provided with a slit groove having an opening on the outer periphery to prevent the temperature of the contacts from rising due to the action of an arc generated at the time of current interruption.
Good breaking performance is obtained in combination with the optimization of the arc distribution.

According to a fourth aspect of the present invention, the fixed electrode rod and the movable electrode rod are connected to the fixed electrode rod and the movable electrode rod on the side where the inclination angle of each tapered portion is small outside the vacuum vessel. It is attached to the drawn out side of the conductor.

In the present invention, the contact is mounted on the side where the inclination angle of the tapered portion of each peripheral edge is small, that is, the side where the distribution of the arc generated at the time of current interruption is biased, is connected to the fixed electrode rod and the movable electrode rod. Drawn main circuit conductor,
That is, it is performed in the direction opposite to the direction of action of the electromagnetic force caused by the main circuit current, cancels out the bias of the arc distribution due to the action of the electromagnetic force, and produces a desirable arc distribution widely diffused over the entire surface of the contact point. Get good blocking performance.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1 The present invention will be described below in detail with reference to the drawings showing an embodiment. FIG. 1 shows a first embodiment of a vacuum valve according to the present invention.
2 is an enlarged view of the vicinity of the contact, and FIG. 3 is a plan view taken along line III-III in FIG.

The vacuum valve shown in FIG. 1 has a disk shape at the ends of the opposed fixed electrode rod 2 and movable electrode rod 3 inside the vacuum vessel 1 as in the conventional vacuum valve shown in FIG. The contacts 4 and 4 are coaxially mounted. The vacuum vessel 1 is a hollow vessel configured by closing both sides of a cylindrical main body 10 made of an insulating material such as ceramics with end plates 11 and 12, and the inside thereof is evacuated to 10 ⁻⁷ Torr by vacuum evacuation. A high vacuum is maintained before and after.

The fixed electrode rod 2 in the form of a round bar is a vacuum vessel 1
The movable electrode rod 3, which is fixedly supported by a support hole that penetrates a substantially central portion of one end plate 11 inward and outward, and also forms a round bar shape
Is inserted through a through hole formed substantially at the center of the other end plate 12 of the vacuum vessel 1, and is movably supported on the peripheral portion of the through hole through a bellows 30 provided between the through hole and the through hole. ing. The ends of the fixed electrode rod 2 and the movable electrode rod 3 are opposed to each other inside the vacuum vessel 1, and the opposite ends are coaxially opposed to the contacts 4 and 4, both of which are disc-shaped. Each is fixed.

Fixed electrode rod 2 protruding outside vacuum vessel 1
The other side is connected to the bus-side conductor 6. Similarly, the other side of the movable electrode rod 3 protruding outside the vacuum vessel 1 is connected to an operation mechanism (not shown) via an operation rod 31 which is coaxially connected, and a load-side conductor facing the side. 7 is connected via a flexible conductor 8. The busbar-side conductor 6
The load-side conductor 7 is drawn out to the same side as shown in the figure, and is separately connected to a bus and a power transmission cable (not shown).

As shown in FIG. 2, the contacts 4 and 4 attached to the fixed electrode rod 2 and the movable electrode rod 3 face each other at the center on the side opposite to the other, and are moved by the movement of the movable electrode rod 3 described later. It has opposed surfaces 40, 40 that come in contact with and separate from each other, and has tapered portions 41, 41 that are provided around the outer surfaces of the opposed surfaces. These tapered portions 41, 41 have the same width in the radial direction over the entire circumference, as shown in FIG. 3, and are formed so as to have an inclination to reduce the thickness on the outer peripheral side, as shown in FIG. However, the inclination angle with respect to the opposing surfaces 40, 40 is set to a maximum angle (= θ ₁ ) on one side in the radial direction and a minimum angle (= θ ₂ ) on the other side. Is continuously changed in the circumferential direction.

As shown in FIG. 1, the contacts 4 and 4 having the tapered portions 41 and 41 are connected to the fixed electrode rod 2 and the movable electrode rod 3 outside the vacuum vessel 1 as shown in FIG. The tapered portions 41, 41 are attached to the ends of the fixed electrode rod 2 and the movable electrode rod 3 with the side where the inclination angle of the tapered portions 41, 41 is minimized facing the lead-out side of the conductor 6 and the load side conductor 7).

In the vacuum valve constructed as described above, similarly to the conventional vacuum valve, the movable electrode rod 3 is moved in the axial direction by the operation force applied from the operation mechanism (not shown) via the operation rod 31. In the state where the central opposing surfaces 40, 40 of the contacts 4, 4 fixed to the movable electrode rod 3 and the fixed electrode rod 2 are separated from each other and are in contact with each other, the fixed electrode rod 2, the contact 4, 4. The main circuit current flows from the bus-side conductor 6 to the load-side conductor 7 via the movable electrode rod 3 and the flexible conductor 8, and when the two are separated from each other, the main circuit current becomes high inside the vacuum vessel 1. It is cut off between the opposed contacts 4 and 4 while maintaining a predetermined insulation distance under vacuum. Thus, the contacts 4 and 4 due to the movement of the movable electrode rod 3
The main circuit current is opened and closed according to the contact and separation of the main circuit.

At this time, the flexible conductor 8 connecting the movable electrode bar 3 and the load-side conductor 7 has an effect of allowing the movable electrode bar 3 to move with respect to the fixedly provided load-side conductor 7. The bellows 30 interposed between the movable electrode rod 3 and the vacuum vessel 1 has a function of allowing the movable electrode rod 3 to move while maintaining a vacuum inside the vacuum vessel 1.

During the operation as described above, when the contacts 4, 4 separate from each other due to current interruption, an arc generated between them is caused by the action of the tapered portions 41, 41 formed on the peripheral edges of the contacts 4, 4. Although the distribution spreads over the entire opposing surface, in the vacuum valve of the present invention, since the inclination angles of the tapered portions 41, 41 are different as described above, the separation distance between the opposing surfaces of the contacts 4, 4 is increased. Is larger at the circumferential position where the tapered portions 41 and 41 have the maximum angle θ ₁ and smaller at the circumferential position where the taper portions 41 and 41 have the minimum angle θ _{2. The} arc generated between the contacts 4 and 4 is shown in FIG. as shown surrounded by a dashed line, when you Katayoro semi region a ₁ on the side having the minimum angle theta _2.

On the other hand, the arc generated between the contacts 4 and 4 includes the fixed electrode rod 2, the movable electrode rod 3 and the flexible conductor from the busbar side conductor 6 drawn to one side outside the vacuum vessel 1. 8, the electromagnetic force generated by the current flowing through the “U” -shaped current path connected to the load-side conductor 7 drawn to the same side as the bus-side conductor 6 is opposite to the direction of the drawer, that is, FIG. Acting to the left in FIG. 2 and FIG. 3, the arc is, as shown in FIG.
When you Katayoro semi region A ₂ in the direction opposite side of the drawer.

As described above, the arc generated between the contacts 4 and 4 due to the interruption of the main circuit current is generated on the right side of the drawing by the action of the tapered portions 41 and 41 having different inclination angles, and is generated by the main circuit current. As shown in FIG. 3, the actual arc is formed by hatching in FIG. shows the diffuse distribution in the area a ₃ throughout, is entirely effective utilization of contacts 4,4, excellent interruption performance is stably obtained.

Embodiment 2 FIG. 4 is an enlarged view of the vicinity of a contact on the movable electrode side showing a vacuum valve according to Embodiment 2 of the present invention, and FIG.
It is a top view by a line.

As shown in the figure, the contact 4 attached to the tip of the movable electrode rod 3 has a slope on the periphery of the central facing surface 40 in the direction of reducing the thickness on the outer periphery side, as in the first embodiment. The tapered portion 41 is provided with a peripheral angle. The inclination angle of the tapered portion 41 with respect to the facing surface 40 is a maximum angle (= θ ₁ ) on one side in the radial direction and a minimum angle (= θ ₁ ) on the other side. θ ₂ ), and the interval between them is continuously changed in the circumferential direction.

The contact 4 has such a structure that the tapered portion 41 has the minimum angle θ ₂ with the movable electrode rod facing the lead-out side of the conductor outside the vacuum vessel 1 (the side indicated by the arrow in the figure). 3, the attachment is performed via a coil electrode 9 fixed to the tip of the movable electrode rod 3, unlike the first embodiment.

As shown in FIG. 5, the coil electrode 9 is a ring-shaped base 9a coaxially fitted to the tip of the movable electrode rod 3.
, And a plurality of (four in the figure) coil portions 9b, 9b,... Provided at equal intervals on the periphery of the base portion 9a. Each of the coil portions 9b has an arm portion radially extending from the outer periphery of the base portion 9a, and a tip end of the arm portion having a diameter substantially equal to the outer diameter of the contact 4 and facing the same side in the circumferential direction. An arc portion extending so as to have a length that does not abut each other.
Supports 9c, 9c,... Thickened toward the side opposite to the side on which the movable electrode rod 3 is mounted are provided at the tips of these arc portions, and the contacts 4 are provided on the support bases 9c, 9c. ... is joined to the end face.

In the vacuum valve according to the second embodiment having the contact 4 configured as described above, the arc generated when the main circuit current is cut off has a taper provided at the peripheral edge of the contact 4 with the above-described inclination. Due to the action of the portion 41, the distribution spread over the entire surface of the contact 4 including the tapered portion 41,
An excellent breaking performance can be obtained by utilizing the entire surface of the contact 4, and when the arc is generated, the current generated by the arc causes the coil portions 9b of the coil electrode 9 supporting the contact 4 to have the same shape.
In response to this, an axial magnetic field is generated according to the right-hand rule, and the arc is confined within the diameter of the contact 4 by the action of the magnetic field, thereby suppressing the diffusion of metal vapor into the vacuum vessel 1. be able to.

FIGS. 4 and 5 show the structure of the contact 4 on the movable electrode side, but the contact 4 on the fixed electrode side has the same structure, that is, the coil electrode 9
The fixed electrode rod 2 and the movable electrode rod 3 are provided with the coil electrodes 9, 9 so that the confinement of the arc within the diameter of the contact 4 can be more effectively performed. Can be made.

Third Embodiment FIG. 6 is an enlarged sectional view showing the vicinity of a contact on the movable electrode side showing a vacuum valve according to a third embodiment of the present invention.
It is a top view by the II-VII line.

As shown in the figure, the contact 4 attached to the tip of the movable electrode rod 3 is provided on the periphery of the central facing surface 40 in the same direction as in the first and second embodiments so as to reduce the thickness on the outer peripheral side. The taper portion 41 is provided so as to have an inclination of the inclination angle of the taper portion 41 with respect to the facing surface 40 is set to a maximum angle (= θ ₁ ) on one side in the radial direction.
The other side has a minimum angle (= θ ₂ ), and the space between them is continuously changed in the circumferential direction. The side having the taper portion 41 having the minimum angle θ ₂ is a conductor of the conductor outside the vacuum vessel 1. It is attached to the tip of the movable electrode bar 3 toward the drawer side (the side indicated by the arrow in the figure).

Further, the contact 4 shown in the third embodiment is formed in a spiral shape having one end opened at the outer peripheral edge and the same direction in the circumferential direction until the other end reaches the inside of the central facing surface 40. Are provided (four in the figure) and have a windmill-shaped plane shape as shown in FIG.

In the vacuum valve according to the third embodiment having the contact 4 configured as described above, the action of the tapered portion 41 provided on the peripheral edge of the contact 4 causes an interruption when the main circuit current is relatively small. Shows a distribution in which the breaking arc spreads over the entire surface of the contact 4 including the tapered portion 41, so that excellent breaking performance can be obtained by utilizing the entire surface of the contact 4 and a local arc caused by a concentrated arc when the breaking current is large. .. Are suppressed by the action of the slit grooves 42.

Although FIGS. 6 and 7 show the structure of the contact 4 on the movable electrode side, it is desirable that the contact 4 on the fixed electrode side has the same structure.

[0043]

As described above in detail, in the vacuum valve according to the first aspect of the present invention, the inclination of the tapered portion of the peripheral edge of the contact point attached to the fixed electrode and the movable electrode is set to be maximum on one side in the radial direction.
Since the other side is minimized, the arc is continuously changed in the circumferential direction. Offset, a proper arc distribution state diffused over the entire opposing surface of the contact can be obtained, the entire opposing surface of the contact can be effectively used, and excellent breaking performance can be stably obtained.

Further, in the vacuum valve according to the second aspect of the present invention, since the coil electrode is provided between the electrode rod and the contact constituting the fixed electrode and / or the movable electrode, the magnetic field generated by the action of the coil electrode causes The arc generated at the time of current interruption can be confined within the diameter of the contact, and in combination with the optimization of arc distribution that applies an axial magnetic field to both contacts according to the flow of arc current, excellent interruption performance It will be able to be obtained stably.

Further, in the vacuum valve according to the third aspect of the present invention, since slit grooves extending from the outer periphery toward the inside are formed at a plurality of locations in the circumferential direction of the contact, the contact is locally concentrated by a concentrated arc generated when a large current is interrupted. Temperature can be suppressed, and excellent breaking performance can be stably obtained together with optimization of the arc distribution.

In the vacuum valve according to the fourth aspect of the present invention, the contact is mounted with the tapered portion having the smaller inclination angle directed toward the lead-out side of the main circuit conductor, so that the electromagnetic force caused by the main circuit current is reduced. The bias of the arc distribution due to the action is offset, the proper arc distribution state diffused to the entire opposing surface of the contact is obtained, the entire opposing surface of the contact can be used effectively, and excellent breaking performance can be obtained stably. Etc.
The present invention has excellent effects.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a configuration of a main part of a vacuum valve according to a first embodiment of the present invention.

FIG. 2 is an enlarged view near a contact point of the vacuum valve shown in FIG.

FIG. 3 is a plan view taken along the line III-III of FIG. 2;

FIG. 4 is an enlarged view near a contact point of a vacuum valve according to a second embodiment of the present invention.

FIG. 5 is a plan view taken along line VV in FIG. 4;

FIG. 6 is an enlarged view near a contact point of a vacuum valve according to a third embodiment of the present invention.

FIG. 7 is a plan view taken along line VII-VII in FIG.

FIG. 8 is a side sectional view showing a configuration of a main part of a conventional vacuum valve.

FIG. 9 is an enlarged view of the vicinity of a contact point of the vacuum valve shown in FIG.

FIG. 10 is a plan view taken along line XX of FIG. 9;

[Explanation of symbols]

1 vacuum vessel, 2 fixed electrode rods, 3 movable electrode rods, 4
Contact point, 6 bus-side conductor, 7 load-side conductor, 9 coil electrode, 41 taper part, 42 slit groove.

Claims (4)

[Claims] 1. A disk-shaped contact which is attached to the distal end of a fixed electrode and a movable electrode which come into contact with and separate from each other in a vacuum vessel, and which faces substantially coaxially, and an opposing surface of each of these contacts. The peripheral edge of the outer peripheral side is provided with a tapered portion having a slope in a direction of reducing the thickness of the outer peripheral side, the inclination angle of the tapered portion with respect to the facing surface, the maximum one side in the radial direction, the other side Characterized in that it is continuously changed in the circumferential direction while minimizing the pressure. 2. A coil electrode for generating an axial magnetic field at both contacts according to the flow of an arc current, between a contact and an electrode rod constituting a fixed electrode and / or a movable electrode. Vacuum valve. 3. The vacuum valve according to claim 1, wherein the contact has a plurality of slit grooves having an opening at an outer peripheral edge and extending toward the center at a plurality of positions in a circumferential direction. 4. A contact is provided on a lead-out side of a conductor connected to the fixed electrode rod and the movable electrode rod outside the vacuum vessel.
The vacuum valve according to any one of claims 1 to 3, wherein each of the tapered portions is attached so that a side having a small inclination angle is directed.