JPH0146971B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power switchgear, and more particularly to a power switchgear having an arc extinguishing chamber that utilizes negative pressure generated as a movable contact moves.

Hereinafter, an example will be explained in which sulfur hexafluoride (SF ₆ ) gas is used as the arc-extinguishing fluid.
FIG. 1 shows a sectional view of an arc extinguishing chamber of an example of a power switchgear according to the prior art that extinguishes an arc by utilizing the pressure increase of SF ₆ caused by the generated arc and the negative pressure accompanying the movement of a movable contact. FIGS. 1A, B, C, and D show the closed state, the partially opened state, and the fully opened state, respectively. In FIG. 1, 1 is a first fixed terminal plate fixedly held on a fixed part (not shown), 2 is a fixed outer cylinder whose one end is fixed to the fixed terminal plate 1, and 3 is the fixed outer cylinder 2. an insulating nozzle having a tapered portion 31 that is inserted and fixed into an opening at the other end and expands outward;
4 is a fixed contact whose one end is fixed to the fixed terminal plate 1 and the other end is provided with a contact end, and 5 is slidably inserted into the insulating nozzle 3 and is driven by a drive device (not shown). A shaft hole 51 is driven in the left-right direction to contact and separate from the fixed contact 4, and a shaft hole 51 is bored in the axial direction from one end on the fixed contact 4 side, and a side hole 52 penetrates from the shaft hole 51 to the outer circumference. 6 is a second fixed terminal plate fixedly held on a fixed part and penetrated by the movable contact 5; 7 is a current collector for energizing the movable contact 5 fixed to the fixed terminal plate 6;
8 is a cylinder whose one end is fixed to the fixed terminal plate 6;
9 is a piston that is fixed to the movable contact 5 and slides on the inner surface of the cylinder 8; 10 is a fixed terminal plate 1, a fixed outer cylinder 2, when the fixed contact 4 and the movable contact 5 are closed;
Insulating nozzle 3, fixed contact 4 and movable contact 5
A storage chamber formed by and storing cold gas, 11
is a suction chamber constituted by the movable contact 5, the fixed terminal plate 6, the cylinder 8 and the piston 9, and 12 is an arc generated between the fixed contact 4 and the movable contact 5 which are separated. The above-mentioned arc extinguishing chamber is housed in a container (not shown) in which SF ₆ is sealed. The shaft hole 51 and the side hole 52 form an arc suction guide, and the insulating nozzle 3 and the movable contact 5
The surrounding surface of the storage chamber 1 is moved by the movement of the movable contactor 5.
0 and the outside of the storage container.

Next, the operation of the above arc extinguishing chamber will be explained.

In order to break the electric path between the fixed contact 4 and the movable contact 5, which are in the closed state as shown in FIG. 1A, the movable contact 5 is slid to the right in the drawing by the drive device. As a result, as shown in FIG. 1B, an arc 12 is generated between the end faces of the fixed contact 4 and the movable contact 5, but as the movable contact 5 moves, the piston 9 fixed to it also moves. As a result, the volume of the suction chamber 11 increases and negative pressure is generated, so that the arc 12 is sucked into the shaft hole 51 as shown by the solid arrow in FIG.
The cold gas inside is absorbed by the negative pressure and mixes with the arc 12, extinguishing the arc.

However, when a large current is cut off, the suction chamber 11 that generates negative pressure is filled with high-temperature exhaust gas heated by the arc 12 and discharged from the side hole 52, and the generation of negative pressure is stopped. In that case, the cold gas in the storage chamber 10, which has been compressed and increased in pressure due to the arc generation, is as shown by the dotted arrow in FIG.
The arc 12 is directly discharged to the outside of the storage chamber 10 through the discharge guide, and the arc 12 is cooled by the exhaust gas and extinguished. When the arc is extinguished and the disconnection is completed, the current interruption is completed as shown in FIG. 1D.

However, in the power switchgear according to the above-mentioned prior art, the temperature of the gas in the storage chamber 10 may rise excessively due to the heat of the arc 12 when a large current is interrupted, and There was a drawback that the arc 12 could not be cooled sufficiently and the arc could fail to be extinguished. Further, there was a drawback that the cold gas and the arc 12 could not be sufficiently mixed even when a small current was interrupted.

This invention has been made in view of the above points, and includes providing a communication guide section that communicates the storage chamber with the inside of the storage container outside the arc-extinguishing chamber via the arc generation space, in addition to the discharge guide section. Therefore, when a large current is interrupted, the high temperature fluid in the storage chamber can be easily discharged to the outside of the arc extinguishing chamber, and when a small current is interrupted, the arc extinguishing fluid outside the arc extinguishing chamber is sucked into the suction guide section to promote arc extinguishing. The object of the present invention is to provide a power switchgear that is configured to do the following.

The present invention will be explained below based on examples.

FIG. 2 is a cross-sectional view of the arc extinguishing chamber of an embodiment of the power switchgear according to the present invention, and FIGS. 2A, B, C, and D show the closed state, the partially opened state, and the fully opened state, respectively. , Figure 2B is when a large current is interrupted,
FIG. 2C shows the state when a small current is interrupted. In FIG. 2, the same reference numerals as in FIG. 1 represent the same components as shown in FIG. Reference numeral 13 has a cylindrical through hole in the axial direction, one end of which is fixed to the fixed terminal plate 1, and the other end of which is inserted into the shaft hole 51 of the movable contact 5 when the fixed contact 4 and the movable contact 5 are closed. The arc contact 14 is an opening that passes through the fixed terminal plate 1 and communicates with the through hole of the arc contact 13. A communication guide portion is formed by the arc contact 13 having a through hole and the opening 14 communicating with the through hole.

Next, the operation of the arc extinguishing chamber of the embodiment will be explained.

In order to interrupt the electrical circuit between the fixed contact 4 and the movable contact 5 which are in the closed state as shown in FIG. 2A, the movable contact 5 is moved by a drive device (not shown). When you slide it to the right, the
An arc is generated between the fixed contact 4 and the movable contact 5, and then transferred to generate an arc 12 between the arc contact 13 and the movable contact 5. As the movable contactor 5 moves, the piston 9 fixed thereto also moves, thereby increasing the volume of the suction chamber 11 and generating negative pressure, which is sucked into the shaft hole 51 of the arc 12 and at the same time, the inside of the storage chamber 10. The cold gas is also sucked in by the negative pressure and mixed with the arc 12 to extinguish the arc.
In the arc extinguishing chamber according to the prior art, when a large current is cut off, the temperature of the gas in the storage chamber 10 rises excessively as described above, and the arc 12 is not sufficiently cooled by the exhaust gas from the storage chamber 10. In addition, the high-temperature exhaust gas is also discharged from the discharge guide section as shown by the dotted line arrow in the figure, but it also enters the suction chamber 11, and the suction chamber 11 is filled with the high-temperature exhaust gas, generating negative pressure. However, the arc extinguishing chamber of the example has an arc contact 1 having a through hole.
3 and an opening 14, and is provided with a communication guide section that communicates the storage chamber 10 with the outside of the arc extinguishing chamber.
Since the high temperature gas of 0 can be discharged to the outside of the arc extinguishing chamber through this communication guide section, an excessive rise in the temperature of the gas in the storage chamber 10 can be prevented and arc extinguishing can be performed satisfactorily. Furthermore, when a small current is interrupted, a pressure increase due to the expansion of the gas in the storage chamber 10 cannot be expected, and the cold gas in the storage chamber 10 is sucked into the suction guide part by the negative pressure in the suction chamber 11 and mixed with the arc 12. However, in the arc extinguishing chamber according to the prior art, the amount of cold gas sucked from the storage chamber 10 was insufficient and the arc extinguishing ability was insufficient, but in the arc extinguishing chamber of the example , as shown by the arrow Y in FIG.
Since the arc 12 is cooled by being mixed with the cold gas from zero, the arc 12 can be easily extinguished.

In the above embodiment, a case has been described in which the cylinder 8 forming the suction chamber is fixed to the fixed terminal plate 6 and the piston 9 is fixed to the movable contact 5, but the piston fixed to the fixed terminal plate and the movable A suction chamber that generates negative pressure can also be formed by a cylinder fixed to the contact.

In the above description of the prior art and embodiments, the case where SF ₆ was used as the arc-extinguishing fluid was explained, but the present invention can also be applied to power switchgear using other arc-extinguishing fluids such as air and oil. Can be applied.

As described in detail above, in the power switchgear according to the present invention, a communication guide part is provided that communicates the storage chamber and the inside of the storage container outside the arc-extinguishing chamber via the arc generation space, separately from the discharge guide part. This makes it easy to discharge the high-temperature fluid in the storage chamber to the outside of the arc-extinguishing chamber when a large current is interrupted, and prevents an excessive temperature rise in the arc-extinguishing fluid in the storage chamber. Fluid can be absorbed into the suction guide to promote arc extinction.

[Brief explanation of drawings]

1A to 1D are sectional views for explaining the configuration and operation of the arc extinguishing chamber of a power switchgear according to the prior art, and FIGS. 2A to 2D are arc extinguishing chambers of an embodiment of the power switchgear according to the present invention. FIG. 2 is a cross-sectional view for explaining the configuration and operation of the FIG. In the figure, 1 is a first fixed terminal plate, 2 is a fixed outer cylinder, 3 is an insulating nozzle, 4 is a fixed contact, 5 is a movable contact, 6 is a second fixed terminal plate, 8 is a cylinder, and 9 is a 10 is a storage chamber, 11 is a suction chamber, 12 is an arc, 13 is an arc contact, and 14 is an opening in the first fixed terminal plate 1. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A fixed outer cylinder whose one end is fixed to the first fixed terminal plate and whose other end is provided with a nozzle part, and whose one end is fixed to the first fixed terminal plate.
a fixed contact fixed to the fixed terminal plate and having a contact end at the other end; a movable contact that closes and opens with respect to the fixed contact through the nozzle part;
When both the contacts are closed, a storage chamber is formed by the first fixed terminal plate, the fixed outer cylinder, and both the contacts and stores an arc-extinguishing fluid, and the movable contact is provided outside the fixed outer cylinder. a second fixed terminal plate through which the child passes; a cylinder and a piston, one of which is fixed to the second fixed terminal plate and the other fixed to the movable contact; the second fixed terminal plate; and the movable a suction chamber formed by a contactor whose volume increases as the movable contact moves apart; and a suction guide section that communicates the storage chamber and the suction chamber through the interior of the movable contact. an arc-extinguishing chamber having an arc-extinguishing chamber; and a storage container accommodating the arc-extinguishing chamber and filled with an arc-extinguishing fluid, wherein the storage container is provided between the nozzle portion and the movable contact when the movable contact is opened and opened. A discharge guide portion is formed for discharging the arc-extinguishing fluid in the chamber into the storage container outside the arc-extinguishing chamber, wherein an axial through hole is formed and one end is fixed to the first fixed terminal plate. The other end is provided with a cylindrical arc contact that engages with the movable contact when the fixed contact and the movable contact are closed, and the first fixed terminal plate is provided with the arc contact. A power switching device characterized in that an opening communicating with the above-mentioned through hole is formed.