JP2002270073A - Electrode of vacuum circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent arcs from being concentrated by equalizing the distribution of magnetic field. SOLUTION: A contactor 102 is fixed to the opening end face of a cup-shaped outside cup 101, and an inside cup 104 is installed in an inside space formed of the outside cup 101 and the contactor 102. A slanted slit 101a formed in the outside cup 101 is opposed to a slanted slit 104a formed in the inside cup 104. By this, the center part of the vertical magnetic field produced by the outside cup 101 is eliminated by a vertical magnetic field produced by the inside cup 104, and the distribution of the magnetic field is equalized on the entire surface of an electrode 100. Thus, an arc produced is dispersed to increase a breaking limit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode of a vacuum circuit breaker, and more particularly to an electrode for a cup-shaped electrode in which a magnetic field distribution is made uniform to prevent arc concentration.

[0002]

2. Description of the Related Art In order to improve the breaking performance of a vacuum circuit breaker, it is necessary to receive the damage caused by the arc on the entire electrode surface without concentrating the arc generated between the electrodes at the time of breaking. In order to receive the damage caused by the arc on the entire electrode surface, a spiral electrode structure as shown in FIG. 13 and a vertical magnetic field electrode (axial magnetic field electrode) structure as shown in FIGS. 14 and 15 are employed.

In the spiral electrode structure shown in FIG. 13, a plurality of spiral electrodes 1a for arc driving are provided around a fixed contact 1 and a plurality of arc driving spiral electrodes are provided around a movable contact 2. An electrode 2a is provided. Due to such a structure, the foot (cathode point or anode point) of the generated arc moves (drives) along the spiral electrodes 1a and 2a without being fixed to the electrode surface, and the arc stops at one place. Disappears. This reduces local overheating of the electrodes and increases the current cutoff limit.

In the vertical magnetic field electrode structure shown in FIG. 14, a coil electrode 11a is provided on the non-contact side of the fixed contact electrode 11, and a coil electrode 12a is provided on the non-contact side of the movable contact electrode 12. I have. Coil electrodes 11a, 12a
Has a coil that extends in the circumferential direction attached to the tip of an arm that extends in the radial direction from the center of the shaft. When a current flows in the coil in the circumferential direction, a magnetic field parallel to the arc (longitudinal magnetic field) Occurs. When a vertical magnetic field is applied to the arc in this way, it prevents charged particles from diffusing in the radial direction, stabilizes the arc, reduces arc loss, suppresses the temperature rise of the electrode section, and increases the breaking ability. Can be.

In the vertical magnetic field electrode structure shown in FIG. 15, cylindrical (cup-shaped) electrodes 21 and 22 are obliquely provided with slits 21.
a and 22b. Thus, the oblique slit 21
By inserting a and 22a, a current flows in the circumferential direction and a vertical magnetic field is generated.

[0006]

SUMMARY OF THE INVENTION The present inventor of the present invention has proposed a method shown in FIG.
As a result of research on improving a cup-shaped vertical magnetic field electrode as shown in (1), it was found that such a cup-shaped vertical magnetic field electrode had a problem that the magnetic field was concentrated at the center. That is, the distribution of the magnetic field of the cup-shaped vertical magnetic field electrode shown in FIG. 15 is as shown in FIG. 16, and has a “bell-shaped” magnetic field distribution having a peak at the center. Since the arc tends to concentrate on a portion where the magnetic field is strong, such a magnetic field distribution has a problem that the arc concentrates on the central portion and the contact surface cannot be used effectively.

FIG. 17 is a drawing showing a photograph taken when an arc is generated in the cup-shaped vertical magnetic field electrode shown in FIG. This figure also shows that the arc concentrates at the center of the electrode and that the arc concentrates remarkably on the anode side.

SUMMARY OF THE INVENTION In view of the above prior art, an object of the present invention is to provide an electrode of a vacuum circuit breaker in which a magnetic flux distribution is made uniform and an arc is dispersed.

[0009]

According to the structure of the present invention for solving the above-mentioned problems, a bowl-shaped outer cup having an oblique slit formed therein, and the outer cup is fixed to the outer cup in a state of closing an opening end surface of the outer cup. It comprises a plate-shaped contact and a cylindrical inner cup provided in an inner space formed by the outer cup and the contact and having a slit formed in a direction opposite to the slit formed in the outer cup. It is characterized by the following.

Further, according to the structure of the present invention, instead of the slit, the inner cup is formed with an oblique groove on the peripheral surface of the inner cup, and the direction of the groove is opposite to that of the slit formed on the outer cup. It is characterized by being oriented.

Further, according to the structure of the present invention, the inner cup is provided with a coil material obliquely on the peripheral surface of the inner cup instead of the slit, and the direction of the coil material is the same as that of the slit formed on the outer cup. Is characterized by being in the opposite direction.

The present invention also provides a bowl-shaped outer cup having an oblique slit formed therein, a plate-shaped contact fixed to the outer cup so as to close an opening end face of the outer cup, and an outer cup. And a coil-shaped inner cup wound in the opposite direction to the slit formed in the outer cup and provided in the inner space formed by the contactor.

[0013]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is an exploded perspective view showing a basic configuration of a cup-shaped vertical magnetic field electrode according to an embodiment of the present invention.
This will be described with reference to FIG. The vertical magnetic field electrode 100 shown in FIG.
It is employed as a fixed-side electrode or a movable-side electrode disposed in the arc-extinguishing chamber of the vacuum circuit breaker. In the vertical magnetic field electrode 100, an electrode rod 102 is provided at the center of the bottom surface of a bowl-shaped (that is, a cylindrical shape whose one end surface is closed) outer cup 101.
Has been fixed. On the open end face of the outer cup 101,
The disk-shaped contact 103 is fixed. And, in the internal space formed by the outer cup 101 and the contact 103,
A cylindrical inner cup 104 is provided. Moreover,
The inner cup 104 and the outer cup 101 are arranged concentrically about the axis of the electrode rod 102. Also,
The inner cup 104 is fixed to the bottom surface of the outer cup 101.

In the cylindrical portion of the outer cup 101, a slit 101a is formed obliquely in order to cause a current to flow in the circumferential direction to generate a vertical magnetic field. A current also flows in the inner cup 104 in the circumferential direction. In order to generate a vertical magnetic field,
A slit 104a is formed obliquely. Moreover, the direction of the slit 101a and the direction of the slit 104a are opposite. Here, “oblique” means that the electrode rod 10
It means that it is oblique to the direction of the axis of No. 2.

Since the direction of the slit 101a is opposite to the direction of the slit 104a, the direction of the magnetic field generated by the current flowing through the outer cup 101 and the direction of the magnetic field generated by the current flowing through the inner cup 104 are opposite. Direction. As a result, the magnetic field generated by the outer cup 101 is weakened at the center of the electrode 100, and the magnetic field is strengthened outside the inner cup 104. Thereby, the electrode 10
The overall magnetic field of 0 is uniform from a “bell-shaped” distribution to a “trapezoidal” distribution.

The reason why the magnetic field is made uniform will be described with reference to FIGS. FIG. 2A shows the configuration of only the outer cup 101. At this time, as shown in FIG. 2B, the magnetic field has a "bell-shaped" distribution.

FIG. 3A shows a configuration in which the inner cup 104 is provided inside the outer cup 101.
The magnetic field generated by the outer cup 1 as shown in FIG.
The direction is opposite to the magnetic field by 01.

FIG. 4A shows the structure of this embodiment in which the inner cup 104 is provided inside the outer cup 101, and the electrode 1
As shown in FIG. 4B, the entire magnetic field of 00 is a composite of the magnetic field generated by the outer cup 101 and the magnetic field generated by the inner cup 104. The combined magnetic field of the entire electrode 100 is smaller than the magnetic field of only the outer cup 101 shown in FIG.

The current flowing through the inner cup 104 is
It is adjusted by the material and thickness of the inner cup 104. That is, by adjusting the material and thickness of the inner cup 104, the current flowing through the inner cup 104, and thus the magnetic field generated by the inner cup 104, can be adjusted.
The composite magnetic field of the electrode 100 can be adjusted to be uniform.

When the arc is concentrated at the center of the electrode 100, the current flowing through the inner cup 104 increases.
The magnetic field distribution has a concave shape at the center. As a result, the arc spreads to the periphery, and the outer cup 101 and the inner cup 10
4 and the arc distribution is stabilized in a state where the arc distribution is balanced. That is, the structure of the electrode 100 has an effect of automatically stabilizing the arc distribution.

The reason for the effect of automatically stabilizing the arc distribution will be described with reference to FIGS. 5 and 6, the upper electrode 100 indicates an anode, the lower electrode 100 indicates a cathode, and arrows indicate current.

FIG. 5 shows a state in which the current is concentrated at the center. In this state, more current flows through the inner cup 104. Therefore, the magnetic field at the center decreases and the magnetic field at the peripheral portion increases due to the effects shown in FIGS. Therefore, the current becomes more stable in the peripheral portion. As a result, the current diffuses from the central portion to the peripheral portion, and becomes stable when the current distribution is balanced as shown in FIG.

As described above, the structure of the electrode 100 has a property of stabilizing the arc. A similar effect can be applied to the cathode and anode separately.

Also, in the conventional electrode, as shown in FIG. 17, the arc tends to concentrate on the anode side. In the electrode 100 of the present embodiment, the arc concentration on the anode side can be reduced.

The reason will be described with reference to FIGS. FIG. 7 shows the magnetic field created by the inner cup 104 when current is concentrated on the anode side. As shown in FIG. 7, since the arc is concentrated at the center on the anode side, the magnetic field created by the inner cup 104 on the anode side is strong.
FIG. 8 shows the magnetic field created by the outer cup 104 at a similar current distribution. In this case, the outer cup 1 at the anode
Since the current flowing through the outer cup 101 decreases, the magnetic field generated by the outer cup 101 weakens. FIG. 9 shows a composite of the magnetic field generated by the inner cup 104 and the outer cup 101, and the strength of the magnetic field is uniform on the cathode side (see FIG. 9 (c) )), And becomes strong at the periphery on the anode side (FIG. 9 (b) showing the magnetic field in the BB portion of FIG. 9 (a)).
reference). As a result, the effect of suppressing the arc concentration on the cathode side is produced, and the state is balanced in a state where the arc concentration on the anode is reduced.

Next, modified examples of the inner cup are shown in FIGS. The inner cup 214 in FIG. 10 has an oblique groove 214a in the outer peripheral surface. Note that an oblique groove may be formed in the inner peripheral surface. Inner cup 224 in FIG.
Is obtained by spirally winding a coil material 224a having a low resistance around the peripheral surface of a cylindrical material 224b having a high resistance. Figure 1
2 has a coil shape.

[0028]

As described above, according to the present invention, the inner cup is provided inside the outer cup, and the inner cup is generated in the direction of the longitudinal magnetic field generated by the outer cup. Since the direction of the vertical magnetic field is made opposite, the magnetic field distribution is made uniform throughout the electrode. As a result, the arc can be dispersed throughout the electrode, thereby improving the breaking performance and extending the life of the electrode.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a vertical magnetic field electrode according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a state of an outer cup and a magnetic field.

FIG. 3 is an explanatory diagram showing a state of an inner cup and a magnetic field.

FIG. 4 is an explanatory diagram showing a state of an outer cup, an inner cup, and a magnetic field.

FIG. 5 is an explanatory diagram showing a state of a current and a magnetic field.

FIG. 6 is an explanatory diagram showing a state of a current and a magnetic field.

FIG. 7 is an explanatory diagram showing a state of arc concentration and a magnetic field on the anode side.

FIG. 8 is an explanatory diagram showing a state of arc concentration and a magnetic field on the anode side.

FIG. 9 is an explanatory diagram showing a state of arc concentration and a magnetic field on the anode side.

FIG. 10 is a perspective view showing a modification of the inner cup.

FIG. 11 is a perspective view showing a modification of the inner cup.

FIG. 12 is a perspective view showing a modification of the inner cup.

FIG. 13 is a perspective view showing a conventional spiral electrode structure.

FIG. 14 is a perspective view showing a conventional vertical magnetic field electrode structure.

FIG. 15 is a perspective view showing a conventional vertical magnetic field electrode structure.

FIG. 16 is a characteristic diagram showing a magnetic field distribution of a conventional cup-shaped vertical magnetic field electrode.

FIG. 17 is a state diagram showing a state when an arc is generated.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 vertical magnetic field electrode 101 outer cup 101 a slit 102 electrode rod 103 contact 104 inner cup 104 a slit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yo Nishijima 2-1-1-17 Osaki, Shinagawa-ku, Tokyo Inside the company Meidensha Co., Ltd. (72) Inventor Masayuki Sakaki 2-1-1-17 Osaki, Shinagawa-ku, Tokyo Stock Company F-term (reference) in Shameidensha 5G026 CA01 CB05 CB08 CC03 DA01 DA07 DB06

Claims (4)

[Claims] 1. An outer cup formed with a diagonal slit, a bowl-shaped outer cup, a plate-shaped contact fixed to the outer cup so as to cover an open end face of the outer cup, and an outer cup and the contact. An electrode for a vacuum circuit breaker, comprising: a cylindrical inner cup provided in an inner space formed therein and formed with an oblique slit in a direction opposite to a slit formed in an outer cup. 2. The inner cup according to claim 1, wherein an oblique groove is formed in a peripheral surface of the inner cup instead of the slit, and a direction of the groove is opposite to a slit formed in the outer cup. An electrode of a vacuum circuit breaker characterized by being oriented. 3. The inner cup according to claim 1, wherein a coil material is disposed obliquely on the peripheral surface of the inner cup instead of the slit, and the direction of the coil material is the same as that of the slit formed on the outer cup. Are electrodes of a vacuum circuit breaker, characterized in that they are oriented in opposite directions. 4. An outer cup having an oblong slit formed therein, a cup-shaped contact fixed to the outer cup so as to close an open end face of the outer cup, and an outer cup and the contact. And a coil-shaped inner cup wound in the opposite direction to the slit formed in the outer cup and provided in the inner space formed.