JPH09251827A - Breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a breaker capable of cutting off current from a small current area to a large current area and performing current cutoff with a small operation energy. SOLUTION: A fixed puffer piston 6 and an auxiliary puffer cylinder 9 are provided for an arc drive type gas breaker having a coil 2 and an arc runner 3. This puffer cylinder 9 is a shield structure 5 which alleviates an electric field at the tip end thereof. Also, the puffer cylinder 9 comes into contact with the arc runner during current conduction of a breaker and at an early stage of current shutdown operation and moves together with an movable contact 4 on the way of the current cutoff operation. Therefore, at the early stage of the current cutoff operation, de-arching due to an arc drive effect is performed and on the way of the current cutoff operation current cutoff due to an buffer effect is performed in addition to the arc drive effect.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switch. Examples of the switch of the present invention include a switch for turning on and off a circuit having a load such as a gas breaker for high voltage, a condenser, and a reactor.

[0002]

2. Description of the Related Art A conventional switch is shown in FIGS. FIG. 2 shows the structure of the breaker part of the puffer type gas circuit breaker, and FIG.
Shows the structure of the interruption part of the arc drive type gas circuit breaker. In the figure, the right side of the center line shows the closed state of the circuit breaker,
The left side shows the cut-off state of the circuit breaker. Since the puffer type gas circuit breaker of FIG. 2 and the arc drive type gas circuit breaker of FIG. 3 are well known, detailed description thereof will be omitted.

In the puffer type gas circuit breaker of FIG. 2, the gas in the puffer chamber 7 formed by the movable puffer cylinder 9 and the fixed puffer piston 6 is compressed during the current interruption operation. The compressed gas is guided by the nozzle 13 as shown by the arrow 12, and is blown to the arc generated between the fixed contact 1 and the movable contact 4.
As a result, the arc is extinguished and the current is cut off.

In the arc drive type gas circuit breaker of FIG. 3, when the arc moves to the arc runner 3 during the current interruption operation,
A current flows through the coil 2 to generate a magnetic field. With this magnetic field, the force according to Fleming's left-hand rule acts on the arc,
The arc is driven to rotate. This arc rotation drive means that gas is blown relative to the arc,
The arc is extinguished and the current is cut off.

[0005]

In the puffer type gas circuit breaker of FIG. 2, a large mechanical force is required to compress the gas. Further, the gas is stored until the throat portion of the nozzle 13 passes through the fixed contact 1, so that further mechanical force is required. Further, since the magnitude of increase in the gas pressure in the puffer chamber 7 is directly related to the breaking ability, it is necessary to move the puffer cylinder 9 at high speed in order to secure the breaking ability of the current. A large amount of mechanical energy is required for this high speed operation.

In the arc drive type gas circuit breaker of FIG. 3, the magnitude of the breaking current and the magnitude of the generated magnetic field are related to the breaking ability. Therefore, when the breaking current becomes small, the driving force of the arc becomes small, so that it is difficult to secure the breaking ability in the small current region. An object of the present invention is to provide a switch which can cut off current from a small current range to a large current range and can cut off current with a small operating energy.

[0007]

In order to achieve the above object, the present invention supplementally adds a puffer effect to the arc driving effect of an arc driving type gas circuit breaker. For this purpose, the arc drive type gas circuit breaker, the fixed puffer piston,
Provide an auxiliary puffer cylinder. In this puffer cylinder, a puffer chamber is formed by engaging with a puffer piston, and a shield portion for relaxing an electric field is formed at the tip thereof.

Further, the puffer cylinder is constructed so as to come into contact with the arc runner when the switch is energized and at the beginning of the current interruption operation, and to move together with the movable contact during the current interruption operation. Therefore, the arc is extinguished by the arc driving effect in the initial stage of the current interruption operation, and the current is interrupted by the puffer effect in addition to the arc driving effect during the current interruption operation.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows the structure of the breaker of the switch. In the figure, the right side of the center line shows the closed state of the circuit breaker, and the left side shows the closed state of the circuit breaker. The illustrated breaker is placed in the insulating gas. On the upper electrode 11,
A fixed contact 1, a coil 2 and an arc runner 3 are provided. The arc runner 3 is connected to the upper electrode 11 via the coil 2.
Connected to The movable contact 4 is moved in the vertical direction in the drawing by an operation mechanism (not shown) to come into contact with or separate from the fixed contact 1. A cylinder retainer 10 is attached to the movable contact 4.

Inside the cylinder holder 10, an auxiliary puffer cylinder 9 and a compression spring 8 are arranged. The puffer cylinder 9 is made of an insulating material. Compression spring 8
Applies a force with which the puffer cylinder 9 comes into contact with the arc runner 3 in the closing state on the right side of the drawing. Further, the cylinder retainer 10 has a portion that engages with the puffer cylinder 9, and prevents the puffer cylinder 9 from coming off, and at the same time, allows the puffer cylinder 9 to move together with the movable contact 4 during the current interruption operation. ing.

Further, the tip of the puffer cylinder 9, that is, the fixed contact 1 side, constitutes a shield portion 5 formed in a shape for relaxing an electric field. The shield portion 5 is covered with an arc resistant insulator such as tetrafluoroethylene resin. In addition,
This coating may be applied not only to the shield part 5 but also to the entire puffer cylinder 9. As shown on the left side of the figure, the shield portion 5 of the puffer cylinder 9 is in a switch-off state,
The movable contact 4 and the movable contact 4 are arranged at substantially the same position.

A fixed puffer piston 6 is provided and forms a puffer chamber 7 with a puffer cylinder 9. Next, the current interruption operation will be described. In the switch-on state on the right side of the drawing, current flows through the path of the upper electrode 11-fixed contact 1-movable contact 4.

When the current is cut off, the movable contact 4 is moved downward in the figure by an operating mechanism (not shown). First, the fixed contact 1 and the movable contact 4 are separated from each other, and an arc is generated between the contacts. At this time, the puffer cylinder 9 does not move because it is not engaged with the cylinder retainer 10, and gas compression in the puffer chamber 7 is not performed.
Therefore, the operation energy for moving the movable contact 4 can be small.

When the movable contact 4 further moves downward, the arc moves to the arc runner 3, and the current flows through the path of the upper electrode 11-coil 2-arc runner 3-arc-fixed contact 4. Therefore, coil 2
By the magnetic field generated by, a force according to Fleming's left-hand rule is generated in the arc, and the arc is rotationally driven.
This rotation drive relatively blows gas onto the arc, and extinguishes the arc.

When the breaking current is in the large current region, the driving force of the arc becomes large, so that the arc extinguishing ability by the arc driving effect becomes large. Therefore, it is not necessary to move the movable contact at high speed in order to cut off a large current, and the operating energy can be small. When the movable contact 4 further moves downward, the cylinder retainer 10 engages with the puffer cylinder 9, and the puffer cylinder 9 moves downward together with the movable contact 4. Then, the gas in the puffer chamber 7 is compressed, the gas flow 12 is generated as shown by the arrow, and the gas is blown to the arc.

The arc is extinguished and the current is cut off by the blowing of the gas flow 12 by the puffer effect in addition to the relative blowing of the gas by the rotational driving of the arc by the magnetic field. During this time, since the tip of the puffer cylinder 9 is always open, the gas pressure in the puffer chamber 7 does not rise as much as the conventional puffer type gas circuit breaker. Therefore, the operating force for driving the movable contact can be small.

According to the switch of the present embodiment described above, the current interruption in the large current region is performed by the arc driving effect.
Further, in the current interruption in the small current region where the arc driving effect does not provide sufficient interruption performance, the puffer effect is added to the arc driving effect, so that the current interruption is effectively performed. Furthermore, since the arc is accompanied by rotation, the wear of the contact occurs evenly at the portion of the contact where the arc is in contact, so that it is possible to obtain a breaker having a longer life than in the case where the arc is not rotated.

At the initial stage of the current interruption operation, it is not necessary to drive the puffer cylinder 9, so that the mechanical operating force can be small. Further, when the puffer cylinder 9 is driven to compress the interior of the puffer chamber 7, the pressure required is lower than in the conventional case, and therefore the mechanical operation force is small. Further, by disposing the shield portion 5 of the puffer cylinder 9 at substantially the same position as the movable contact 4, the electric field near the tip of the movable contact 4 in the current interruption state on the left side of the drawing can be relaxed. Therefore, the withstand voltage performance of the switch is improved, and it is easy to reduce the size and increase the voltage of the switch.

[0019]

According to the present invention, it is possible to obtain a switch which can interrupt the current from a small current region to a large current region and can interrupt the current with a small operating energy.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a breaker in an embodiment of a switch according to the present invention.

FIG. 2 is a cross-sectional view showing a breaking portion in a conventional puffer type gas circuit breaker.

FIG. 3 is a cross-sectional view showing a breaker in a conventional arc-driven gas circuit breaker.

[Explanation of symbols]

 1 ... Fixed contact 2 ... Coil 3 ... Arc runner 4 ... Movable contact 5 ... Shield part 6 ... Puffer piston 7 ... Puffer chamber 8 ... Compression spring 9 ... Puffer cylinder 10 ... Cylinder holder 11 ... Upper electrode 12 ... Gas flow 13 ... Nozzle

Claims (3)

[Claims] 1. A fixed contact, a movable contact,
A coil that generates a magnetic field that rotationally drives the arc and an arc runner, and when the current is cut off, the arc that is generated between the arc runner and the movable contact is rotationally driven by the magnetic field generated by the coil to extinguish the arc. In the container, a fixed puffer piston, a puffer cylinder that engages with the puffer piston to form a puffer chamber, and a shield portion that relaxes an electric field at the tip thereof is formed; In addition to the arc drive effect, the current cutoff is provided in addition to the means for keeping the state in contact with the arc runner during the current application and the state of moving along with the movable contact during the current cutoff operation. A switch that cuts off the current due to the puffer effect during operation. 2. The switch according to claim 1, wherein at least a tip portion of the puffer cylinder is covered with an arc resistant insulator. 3. The opening / closing according to claim 1, wherein the shield portion at the tip of the puffer cylinder and the tip of the movable contact are arranged to be substantially at the same position after the current interruption operation. vessel.