JP3783414B2 - Vacuum circuit breaker - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vacuum circuit breaker, and more particularly to a vacuum circuit breaker provided with an electrode having an arc groove.
[0002]
[Prior art]
In the vacuum circuit breaker, the pair of electrodes arranged opposite to each other in the vacuum valve are brought into contact with and separated from each other, thereby turning on and off. In general, the movable rod is moved up and down with respect to the fixed rod by an operating mechanism provided outside the vacuum valve, and the electrodes provided at the ends of the rods are brought into contact with and separated from each other to perform closing and closing.
[0003]
And when a vacuum circuit breaker interrupts | blocks, an arc generate | occur | produces between electrodes. When this arc stagnates at one location between both electrodes, the temperature of the electrode surface rises due to heat input from the arc, and metal melting occurs. For this reason, when this phenomenon occurs, the consumption of the electrode becomes severe, and further, the interruption performance is remarkably deteriorated because excess metal particles exist between the electrodes.
[0004]
Therefore, in the conventional vacuum circuit breaker, various devices are applied to the electrode structure of the vacuum circuit breaker in order to solve the problem of arc generation when the current is interrupted.
For example, by providing a spiral spiral arc groove in the arc electrode, the current flowing through the electrode gives a magnetic drive force in the rotational direction along the arc groove to the generated arc, and the arc is always between the electrodes. By adopting a configuration in which the electrode is moved, the arc is not stagnated in a place where the electrode is present, the metal melting on the surface of the electrode is suppressed for a long time, and the consumption of the electrode is suppressed, thereby improving the interruption performance.
[0005]
[Problems to be solved by the invention]
However, in a conventional vacuum circuit breaker using electrodes having spiral arc grooves, when the vacuum circuit breaker is made small, the arc generated between the electrodes is subjected to electromagnetic force by the magnetic field generated by the current flowing through the external conductor. .
[0006]
As a result, the area where the arc moves on the electrode, that is, the effective area of the movement is reduced, and there is a problem that the interruption performance is lowered.
[0007]
An object of the present invention is to provide a vacuum circuit breaker capable of improving the breaking performance by actively magnetically driving an arc as much as possible along the outer periphery of the electrode.
[0008]
[Means for Solving the Problems]
An object of the present invention is to provide a vacuum circuit breaker capable of improving the breaking performance by actively magnetically driving an arc as much as possible along the outer periphery of the electrode.
[0009]
To achieve the above object, the present invention comprises an electrode having a spiral arc groove disposed in a vacuum bulb, a rod extending from the back of the electrode to the outside of the vacuum bulb, and an external conductor connected to the rod. In a vacuum circuit breaker
The portion sandwiched between the tip of the arc groove of the electrode, the inner end of the arc groove located next to the rotation direction of the arc groove, and the intersection of the tangent to the arc groove passing through the end and the outer periphery of the electrode A mark is provided at a position corresponding to, and the outer conductor is drawn out in the mark direction .
[0011]
In order to achieve the above object, in the vacuum circuit breaker according to the present invention, the tip of the arc groove is adjacent to the rotation direction of the arc groove as the part on the electrode where the radial component of the electromagnetic force acting on the arc is maximized. The inner edge of the arc groove located at the electrode and the portion sandwiched between the tangent to the arc groove passing through this edge and the outer circumference of the electrode are arranged corresponding to the direction of the outer conductor It is.
[0012]
In order to achieve the above object, the vacuum circuit breaker according to the present invention has a pair of electrodes in the vacuum valve, and a portion on each electrode where the radial component of the electromagnetic force acting on the arc is maximized, Each is arranged in the direction of the outer conductor.
[0013]
In order to achieve the above object, the present invention provides a vacuum comprising an electrode having an arc groove disposed in a vacuum bulb, a rod extending from the back of the electrode to the outside of the vacuum bulb, and an external conductor connected to the rod. In the circuit breaker, the part sandwiched between the tip of the arc groove, the inner edge of the arc groove located next to the rotation direction of the arc groove, and the intersection of the tangent to the arc groove passing through this edge and the outer circumference of the electrode Is arranged corresponding to the outer conductor.
[0014]
In order to achieve the above object, in the vacuum circuit breaker according to the present invention, the tip of the arc groove, the end inside the electrode of the arc groove located next to the rotation direction of the arc groove, and the arc groove passing through the end The electromagnetic force acting on the arc is adjusted by shifting the portion sandwiched between the intersections of the tangent line and the outer periphery of the electrode clockwise or counterclockwise with respect to the external conductor.
[0015]
In order to achieve the above object, in the vacuum circuit breaker according to the present invention, the tip of the arc groove, the end inside the electrode of the arc groove located next to the rotation direction of the arc groove, and the arc groove passing through the end A portion sandwiched between the intersections of the tangent and the electrode outer periphery is provided in a range of 30 degrees clockwise and counterclockwise from the central portion of the outer conductor in the axial direction.
[0016]
In order to achieve the above object, the vacuum circuit breaker of the present invention includes a pair of electrodes having arc grooves in a vacuum valve, and is positioned next to the arc groove tip of each electrode and the rotation direction of the arc grooves. The end portion of the arc groove inside the electrode and the portion sandwiched between the tangent to the arc groove passing through this end portion and the electrode outer periphery are arranged in the direction of the outer conductor, respectively.
[0017]
In order to achieve the above object, in the vacuum circuit breaker of the present invention, the tip of the arc groove of each electrode, the end inside the electrode of the arc groove located next to the rotation direction of the arc groove, and this end The portion sandwiched between the intersections of the tangent to the passing arc groove and the outer periphery of the electrode is arranged so as to coincide with each other between the electrodes.
[0018]
In order to achieve the above object, in the vacuum circuit breaker according to the present invention, the tip of the arc groove of the electrode, the inner end of the arc groove located next to the rotation direction of the arc groove, and the end pass through this end. A mark is provided at a portion corresponding to a portion sandwiched between the tangent to the arc groove and the outer periphery of the electrode, and the external conductor is drawn out in the mark direction.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to FIGS.
[0020]
FIG. 2 is a diagram showing a longitudinal sectional structure of a vacuum circuit breaker according to an embodiment of the present invention.
[0021]
The vacuum valve 1 is provided with a sealing fitting 3 at the end of an insulating cylinder 2 of a ceramic member, and the inside is vacuum-sealed. A fixed rod 4 and a movable rod 5 are arranged in a corresponding manner in the vacuum valve 1. The fixed rod 4 is fixed to the sealing metal fitting 3A. The movable rod 5 is held by the bellows 6 and the sealing fitting 3B, and the movable rod 5 can be moved in the axial direction by the bellows 6. The shield 11 is disposed outside the electrodes 8 and 9 and is supported by the insulating cylinder 2. An outer conductor 7 extends in the direction perpendicular to both the rods 4 and 5 attached to the fixed rod 4 and the movable rod 5.
[0022]
A fixed electrode 8 and a movable electrode 9 made of, for example, a Cu-Pb alloy are provided at the tips of the fixed rod 4 and the movable rod 5, respectively.
[0023]
When the fixed electrode 8 and the movable electrode 9 are separated and cut off, an arc A is generated between these electrodes. When this arc A is concentrated and ignited at a certain position between both electrodes 8 and 9, the surface temperature of both electrodes 8 and 9 rises and metal melting occurs. It is necessary to give a driving force in order to always move. For this reason, a plurality of arc grooves 10 (three arc grooves 10A, 10B, 10C in this embodiment) are provided on both electrodes 8 and 9, and a magnetic driving force is applied to the arc A.
[0024]
Next, the electromagnetic force acting on the arc A will be described with reference to FIGS.
[0025]
An electromagnetic force F2 having a component in the radial direction of the electrode acts on the arc A by the magnetic field generated by the current flowing through the electrodes 8 and 9. This electromagnetic force F2 passes through the tip 10E of the arc groove 10A, that is, the end inside the electrode of the arc groove 10B located adjacent to the tip 10E of the arc groove 10A and the rotation direction of the arc groove 10A. 10D and the maximum when moving to the triangular portion S in the region sandwiched between three points (10D, 10E, 10F) of the intersection 10F between the tangent L1 to the arc groove passing through the end 10D and the electrode outer periphery. As a result, the arc always goes around the outer periphery.
[0026]
On the other hand, the electromagnetic force F1 due to the Lorentz force from the current flowing through the outer conductor 7 with respect to the arc A always works in the left direction in the figure in the apparatus configuration of FIG. 2, and this electromagnetic force F1 is shown by the arc A in FIG. It becomes the maximum when it moves to the position P closest to the outer conductor 7.
[0027]
Therefore, when an arc generated between the electrodes moves on the electrodes, a region that has passed through the tip 10E of the arc groove 10A that is a portion on the electrodes where the component of the radial electromagnetic force F2 acting on the arc is maximum, That is, the tip 10E of the arc groove 10A, the end 10D inside the electrode of the arc groove 10B located next to the rotation direction of the arc groove 10A, and the intersection 10F of the tangent L1 to the arc groove passing through the end 10D and the outer periphery of the electrode Even when the arc generated between the electrodes moves on the electrodes by arranging the triangular portion S in the region between the three points (10D, 10E, 10F) corresponding to the position closest to the outer conductor 7, The arc can be moved a long distance on the electrode per unit time by drawing a spiral as large as possible (maximum arc is along the outer circumference of the electrode) The arc is thereby prevented from stagnating on the possible electrode, suppressing the molten metal of the electrode surface, thereby improving the breaking performance by suppressing the wear of the electrode.
[0028]
Next, regarding the relationship between the electromagnetic force F1 and the electromagnetic force F2 when the arc A is positioned at the point P, the straight line L2 extending from the electrode center to the midpoint of the sides (10E, 10F) of the triangular portion S and the outer conductor 7 An example in which the angle θ formed is changed will be described with reference to FIGS. 3 to 7, and the effect will be compared with the cutoff performance when θ = 0 ° as 1 in the graph of FIG. 8.
[0029]
(1) When θ = 0 ° As shown in FIG. 3, the triangular portion S, which is a portion on the electrode where the component of the radial electromagnetic force F2 acting on the arc is maximized, is arranged corresponding to the external conductor 7. The electromagnetic force F2 due to the current flowing through the electrodes 8 and 9 is greater than the electromagnetic force F1, that is, the relationship of electromagnetic force F2> electromagnetic force F1. Therefore, since the arc A is pushed by the electromagnetic outer peripheral end 9E and magnetically driven along the surface of the electrode outer peripheral end, the interruption performance is remarkably improved as shown in FIG.
[0030]
(2) When θ = 30 °, the triangular part S moves 30 ° counterclockwise from the center line 0 of the movable rod 5 as shown in FIG. The electromagnetic force F2 is equal to or slightly stronger than the electromagnetic force F1, that is, the relationship of electromagnetic force F1 ≦ electromagnetic force F2, so that the arc A is magnetically driven slightly inside the electrode outer peripheral side compared to when θ = 0 °. Therefore, the arc A travels while drawing a small spiral or circumference as compared to when θ = 0 °, and therefore the arc travel distance per unit time is shortened. Therefore, as shown in FIG. 8, the arc is stagnated as compared to the case of θ = 0 °, and the performance is somewhat worse than the interruption performance.
[0031]
(3) When θ = 60 °, the triangular portion S moves 60 ° counterclockwise from the center line of the movable rod 5 as shown in FIG. Regarding the relationship between the electromagnetic force F2 and the electromagnetic force F1, the electromagnetic force F2 is weaker than the electromagnetic force F1, that is, the relationship of electromagnetic force F1> electromagnetic force F2. Compared to when θ = 30 °, the arc A is pushed into the inner side of the electrodes 8 and 9 having a small driving force and stagnates at the center part of the electrodes 8 and 9, and the size of the spiral or circumference drawn by the arc is reduced. Therefore, the distance traveled by the arc per unit time is shortened, and as shown in FIG. 8, the interruption performance is deteriorated as compared with the case of θ = 30 °, and is not suitable for use.
[0032]
(4) When θ = -30 ° When θ = -30 °, it is the same as when θ = 30 °. As shown in FIG. 6, the relationship between the electromagnetic force F2 and the electromagnetic force F1 at the position where the triangular part S moves 30 ° (−30 °) clockwise from the center line 0 of the outer conductor 7 flows through the triangular part S. The electromagnetic force F2 due to the current is equal to or slightly stronger than the electromagnetic force F1, that is, the electromagnetic force F1 ≦ the electromagnetic force F2.
[0033]
Therefore, the arc A magnetically drives the inner side of the electrode outer peripheral end 9E as compared with the case of θ = 0 °. Therefore, the arc A is somewhat worse than the interruption performance of θ = 0 ° as shown in FIG. You can also
[0034]
(5) When θ = −60 ° When θ = −60 °, it is the same as when θ = 60 °. As shown in FIG. 7, the relationship between the electromagnetic force F2 and the electromagnetic force F1 at the position where the triangular portion S moves 60 ° (−60 °) clockwise with respect to the outer conductor 7 is as follows. It becomes weaker, that is, the relationship of electromagnetic force F1> electromagnetic force F2. Therefore, compared to when θ = −30 °, the arc A is pushed inside the electrodes 8 and 9 having a small driving force, stays in the center of the electrodes 8 and 9, and the spiral or circumference of the arc drawn by the arc is large. Therefore, as shown in FIG. 8, the shut-off performance is deteriorated compared to the case of θ = −30 ° and cannot be used.
[0035]
As described above, according to the present invention, when the triangular portion S of the arc groove 10 is disposed corresponding to the outer conductor 7, when θ = 0, the relation of electromagnetic force F2> electromagnetic force F1 is established. Since the arc A is pushed to the electrode outer peripheral end side and magnetically driven along the electrode outer peripheral end side surface, the interruption performance can be remarkably improved as shown in FIG. 8, and the vacuum valve 1 of the present invention has the triangular portion S. Compared with the prior art that does not correspond to the outer conductor 7, the electrode shape can be reduced.
[0036]
Moreover, since the influence from an external conductor can be reduced, it becomes possible to provide the electrode 8 close to the external conductor 7, and the structure of the whole vacuum circuit breaker including the rods 4 and 5 can be reduced in size.
[0037]
Further, if the triangular portion S is moved by shifting the angle at which the triangular portion S is arranged to correspond to the outer conductor 7 in the clockwise direction or the counterclockwise direction, the electromagnetic force F2 can be adjusted. Can be magnetically driven.
[0038]
Further, if the triangular portion S is positioned in a range of 30 ° clockwise from the angle corresponding to the outer conductor 7 and −30 ° counterclockwise, a stable interruption performance can be obtained without impairing the interruption performance. I can do it.
[0039]
In the above-described embodiment, the case where the arc grooves are provided on both electrodes has been described. However, the electrodes may be used for an electrode provided with an arc groove on one side.
[0040]
In addition, when the electrode is used for the fixed electrode 8 and the movable electrode 9 with an arc groove, the direction of the triangular portion S that is the portion on the electrode where the component of the electromagnetic force F2 in the radial direction acting on the arc is maximized is set. A better effect can be obtained by matching the two electrodes.
[0041]
Further, in the electrode shape of the above-described embodiment, the region on the electrode where the component of the electromagnetic force F2 in the radial direction acting on the arc is maximized is a region close to the adjacent spiral electrode from the tip 10E of the arc groove 10A. In particular, the tip 10E of the arc groove 10A, the end 10D inside the electrode of the arc groove 10B located next to the rotation direction of the arc groove 10A, the tangent L1 to the arc groove passing through the end 10D, and the outer circumference of the electrode The triangular region S in the region sandwiched between the three points (10D, 10E, 10F) of the intersection point 10F is specified, but the region of the electrode where the component of the radial electromagnetic force F2 acting on this arc is maximum is In relation to the shape of the spiral of the electrode, there may be cases where the definition of the triangular portion S specified in this one embodiment cannot be applied in a spiral electrode shape other than one embodiment described above. Even in such a spiral electrode shape, the region on the electrode where the component of the electromagnetic force F2 in the radial direction acting on the arc on the electrode is maximized is specified by electromagnetic field analysis or the like, and this region is arranged in the direction of the external conductor. Thus, an effect equivalent to that of the above-described embodiment can be obtained.
[0042]
For example, FIG. 9 shows another embodiment of the present invention, which is an electrode having a spiral shape different from the electrode of the embodiment described above. In this electrode, as the region where the radial component of the electromagnetic force acting on the arc becomes the maximum, the definition of the triangular portion S described in the above-described one embodiment cannot be applied as it is.
[0043]
Also in this embodiment, as shown in the drawing, the radial component of the electromagnetic force acting on the arc in the region close to the adjacent spiral electrode from the tip 20E of the arc groove 10A is the same as in the above-described one embodiment of the electrode. There is a region S2. However, unlike the definition of the region S in the above-described one embodiment, this region S2 has an end 20D inside the electrode of the arc groove 10B and an intersection 20G between the arc tangent L1 to the arc groove passing through the end 20D and the arc groove 10B. An intersection 20F between the tangent line L4 in the arc groove of the intersection 20G and the electrode outer periphery is defined, and a region S2 sandwiched between the intersections 20G and 20F and the tip 20E of the arc groove 10A can be defined. When the arc moves in the region S2, the radial component of the electromagnetic force acting on the arc is maximized. By arranging this region corresponding to the position closest to the external conductor 7, the arc generated between the electrodes Even when moving upward, the arc moves while drawing the outer periphery of the electrode.
[0044]
The embodiment of FIG. 10 shows an embodiment in which the triangular portion S, which is a portion on the electrode where the component of the electromagnetic force F2 in the radial direction acting on the arc is maximized, is easily arranged in the direction of the external conductor. .
[0045]
S 'is attached as a mark to the portion corresponding to the triangular part S of the hexagonal column clamping nut 15 for fixing the fixing rod 4, and the external conductor 7 is extended to the mark S' side, so that a mounting error at the time of assembly can be avoided. It has been prevented.
[0046]
Further, in FIG. 11, the rods 4 and 5 may be provided with a step at the outer end so as to correspond to the position of the triangular portion S, and S ′ may be attached using the step as a mark, or only the step may be used. The effect of can be achieved.
[0047]
【The invention's effect】
As described above, according to the vacuum circuit breaker of the present invention, for example, when the triangular portion S is disposed corresponding to the external conductor 7, the electromagnetic force F2 on the electrode side becomes stronger than the electromagnetic force F1 due to the external conductor, and the arc A Is pushed to the electrode outer peripheral end side and magnetically driven along the surface of the electrode outer peripheral end side, so that the blocking performance can be remarkably improved as shown in FIG. Compared to the prior art that does not correspond to the conductor 7, the electrode shape can be reduced in size.
[0048]
In addition, since the electrode can be configured to be close to the external conductor, the configuration of the entire vacuum circuit breaker can be reduced in size.
[Brief description of the drawings]
FIG. 1 is a perspective view of an electrode taken along line AA of FIG. 2 which is an embodiment of the present invention.
FIG. 2 is a cross-sectional view of a vacuum valve that is an embodiment of the present invention.
FIG. 3 is a plan view for explaining magnetic drive when the electrodes of FIG. 1 are arranged corresponding to the external conductors.
4 is a plan view for explaining magnetic driving when the electrode of FIG. 1 is moved counterclockwise with respect to an external conductor. FIG.
5 is a plan view for explaining magnetic driving when the electrode of FIG. 1 is moved counterclockwise with respect to the external conductor. FIG.
6 is a plan view for explaining magnetic driving when the electrode of FIG. 1 is moved clockwise with respect to the external conductor. FIG.
7 is a plan view for explaining magnetic driving when the electrode of FIG. 1 is moved clockwise with respect to the external conductor. FIG.
FIG. 8 is a characteristic diagram showing the relationship between the angle at which the electrode of FIG. 1 is moved with respect to the external conductor and the breaking performance.
FIG. 9 is a plan view showing an electrode shape according to another embodiment of the present invention.
FIG. 10 is a perspective view showing a part of a vacuum valve according to another embodiment of the present invention.
FIG. 11 is a perspective view showing a part of a vacuum valve according to another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Vacuum valve, 2 ... Insulating cylinder, 4 ... Fixed rod, 5 ... Movable rod, 7 ... External conductor, 8 ... Fixed electrode, 9 ... Movable electrode, 10, 10A-10C ... Arc groove, S ... Triangular part S

Claims (1)

In a vacuum circuit breaker comprising an electrode having a spiral arc groove disposed in a vacuum bulb, a rod extending outside the vacuum bulb from the back of the electrode, and an external conductor connected to the rod,
The portion sandwiched between the tip of the arc groove of the electrode, the inner end of the arc groove located next to the rotation direction of the arc groove, and the intersection of the tangent to the arc groove passing through the end and the outer periphery of the electrode A vacuum circuit breaker characterized in that a mark is provided at a position corresponding to, and the outer conductor is drawn out in the mark direction .

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