JPH04262331A - Gas blast circuit breaker - Google Patents

Abstract

PURPOSE:To provide a gas blast circuit breaker which can be operated with a small force by lessening outflow of the arc energy from a heat puffer chamber of a double flow heat puffer type gas blast circuit breaker which drives the heat puffer chamber side, heating effectively the gas in the heat puffer chamber, and reducing the weight of the moving part. CONSTITUTION:A contact base 8 is made of a light material 12 such as A1, and the part directly contacted by arcs is made from a heat resistant member 13 or in a structure in which an arc resistant member is built in. A heat puffer chamber 18 is surrounded by a nozzle 5 consisting of insulation, a contact cover 7, and a lightweight member 12. Accordingly the thermal energy outflowing from the heat puffer chamber through its inner wall, and the arc energy heats the gas in the chamber effectively. This causes increase of the gas pressure in the chamber, strengthens gas blow to the arc, and enhances the breaking performance. Because the weight of the moving part decreases, the operating force can be reduced.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power circuit breaker, and more particularly to the structure of a thermal puffer type double flow type gas circuit breaker.

0002

BACKGROUND OF THE INVENTION Puffer-type gas circuit breakers, which are the mainstream of large-capacity gas circuit breakers, have high performance, but because of the puffer reaction force generated, there is a limit to the reduction in operating force, and they are not economical. Therefore, in order to reduce the operating force of the gas circuit breaker, a thermal puffer type gas circuit breaker that actively utilizes arc energy has been proposed. In addition, in order to improve large current interrupting performance,
A double flow method that sprays gas in two directions, upstream and downstream of the nozzle, is effective. An example of a conventional double flow heat puffer type gas circuit breaker will be explained with reference to FIGS. 6 to 8. FIG. 6 shows the state at the time of injection. The interrupting part includes a main fixed contact 1, a fixed contact 2, an electric field relaxation shield 3, a main movable contact 4, a nozzle 5, a movable contact 6, a contact cover 7, a contact base 8, a conductive rod 9, an exhaust guide 10, etc. It consists of Heat puffer room 1
An exhaust flow path 15 provided at 8 is separated from the exhaust guide 10 and communicates with the outside of the heat puffer room. FIG. 7 shows the state in the early stage of the shutoff operation. When the conductive rod 9 is operated rightward in the drawing by an operating device (not shown), the main fixed contact 1 and the main movable contact 4 are first separated, and then the fixed contact 2 and the movable contact 6 are separated. do. Then, an arc 11 is generated between the fixed contact 2 and the movable contact 6, the gas in the thermal puffer chamber 18 is heated by the energy of the arc 11, and the pressure increases. At this time, the opening 16 of the exhaust flow path 15 provided from the axial center of the heat puffer chamber 18 toward the side wall
is closed by the exhaust guide 10, and the nozzle throat 19 is also closed by the fixed contact 2.
No gas flow occurs. FIG. 8 shows the state in the latter half of the shutoff operation. When the fixed contact 2 comes out of the nozzle throat 19, the high-pressure gas heated by the arc energy in the thermal puffer chamber 18 begins to flow downstream of the nozzle. At the same time, the opening 16 of the exhaust flow path 15 is connected to the opening 17 of the exhaust guide 10.
Since the gas in the thermal puffer chamber 18 also flows in the upstream direction of the nozzle, a double flow occurs.

[0003] As described above, the conventional technology actively utilizes arc energy and sprays gas in two directions: upstream of the nozzle and downstream of the nozzle, thereby achieving gas shutoff with low operation force and high ability to interrupt large currents. It is an attempt to provide a vessel.

0004

[Problems to be Solved by the Invention] In the conventional technology, gas is effectively heated using arc energy, the pressure is increased, and the gas is blown onto the arc. is occupied by
Heat escapes easily. That is, there is a problem in that arc energy easily escapes from the inner wall of the thermal puffer chamber to the outside of the thermal puffer chamber, making it impossible to effectively heat the gas within the thermal puffer chamber.

[0005] In addition, in the embodiments of the prior art, the thermal puffer chamber side is driven, so if the contact base were made of copper, the weight of the movable part would increase, so the thermal puffer type was used to eliminate the puffer reaction force. However, there was also the problem that the effect of reducing operating force was lost.

An object of the present invention is to provide a thermal puffer chamber in which arc energy can effectively heat the gas within the thermal puffer chamber, thereby realizing a thermal puffer type gas circuit breaker with excellent interrupting performance. . Further, by reducing the weight of the movable part, the operating force is reduced, and an economical gas circuit breaker is provided.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a contact base made of copper, which constitutes a part of the inner wall of a thermal puffer chamber, which has a lower thermal conductivity than copper. It is made of lightweight material, and heat-resistant or arc-resistant members are incorporated in the parts of the contact base that come into direct contact with the arc to prevent damage caused by the arc.

[0008]

[Function] By constructing the contact base with a combination of a material such as aluminum, which has a thermal conductivity lower than that of copper, and a heat-resistant material or an arc-resistant material, the inner wall of the heat puffer is made of an insulating material such as the nozzle and contact cover. Since it is made of a material with low thermal conductivity or a heat-resistant member, the heat conduction through the inner wall of the heat puffer is reduced, and the arc energy effectively heats the gas, increasing the gas pressure and improving the blocking performance.

Furthermore, by constructing the contact base from a combination of lightweight materials and heat-resistant materials, the weight of the movable parts is reduced.
Operation force can be reduced.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 are longitudinal sectional views of a blocking section showing an embodiment of the present invention. The interrupting part includes a main fixed contact 1, a fixed contact 2, an electric field relaxation shield 3, a main movable contact 4, a nozzle 5, a movable contact 6, a contact cover 7, a contact base 8, a conductive rod 9, an exhaust guide 10, etc. It consists of The conductive rod 9 is connected to an insulated operating rod (not shown) and also has the function of driving the movable part. The figure shows the state in the early stage of the shutoff operation, and corresponds to FIG. 7 showing an example of the prior art. That is, after the main fixed contact 1 and the main movable contact 4 are separated, the fixed contact 2 and the movable contact 6 are separated, and an arc 11 is generated between them. A heat puffer chamber 18 formed by the nozzle 5, contact cover 7, and contact base 8 is generated by the energy of the arc.
The gas inside is heated and the pressure increases. As shown in the enlarged view of the mover side shown in FIG. 2, the contact base indicated by 8 in FIG. made of combinations. The specific heat of aluminum is 0.0212, and that of copper is 0.092, so aluminum conducts less heat. Therefore, compared to when the contact base is made of copper, when the contact base is made of aluminum, less thermal energy leaks out from the thermal puffer chamber, and the arc energy is effectively used to heat the gas inside the thermal puffer chamber. As the temperature increases, the pressure of the gas inside the thermal puffer chamber increases. For this reason, the blowing of gas to the arc is strengthened in the late stage of the interrupting operation (not shown), and the interrupting performance is improved.

Furthermore, since the specific gravity of aluminum is 2.7 and the specific gravity of copper is 8.9, the weight of the copper member is reduced to 30% by changing the material to aluminum. As a result, the weight of the movable part is reduced and the operating force can be reduced, making it possible to realize an economical circuit breaker.

FIG. 3 is an enlarged view of the movable side of a vertical cross-sectional view of a blocking section showing a second embodiment of the present invention. In this embodiment as well, the contact base 8 is made of a lightweight material 12 such as aluminum, but the heat puffer chamber side 18 of the contact base 8 is also made of a heat-resistant material. According to this embodiment, even if the temperature of the thermal puffer chamber 18 rises excessively, the contact base 8 on the thermal puffer chamber 18 side will not be damaged, thereby improving reliability. Further, since most of the contact base is made of lightweight material 12, the effect of reducing the weight of the movable parts is not impaired.

FIG. 4 is an enlarged view of the movable side of a vertical cross-sectional view of a blocking section showing a third embodiment of the present invention. In this embodiment, the tip of the contact base 8 is made of an arc-resistant material 14 such as copper-tungsten, and the rest of the contact base 8 is made of a lightweight material 12 such as aluminum. Combined with heat-resistant materials. According to this embodiment, even if an arc occurs at the fitting portion of the movable contactor 6 and the contact base 8 when a large current is applied, the tip portion of the contact base 8 will not be damaged. Note that in this embodiment as well, the thermal puffer chamber is surrounded by the nozzle 5, the contact cover 7, and the heat-resistant material 13, so that the leakage of thermal energy from the thermal puffer chamber is small, and the arc energy is effectively used to heat the gas. The same effect can be achieved. Copper-tungsten has a higher specific gravity than copper, so it is not effective in reducing the weight of moving parts, but copper-tungsten is only used at the tip of the contact base, and most of the contact base is made of lightweight material. 12, the weight of the movable parts is reduced as a whole, and the operating force is reduced.

FIG. 5 is an enlarged view of the movable side of the vertical cross-sectional view of the blocking section showing a fourth embodiment of the present invention. In this embodiment, the contact base 8 is made of aluminum, and its side wall side, that is, the surface in contact with the exhaust guide 10, is anodized. Since the alumite 20 has excellent corrosion resistance and exhibits electrical insulation properties, it can prevent current from flowing from the contact base 8 to the exhaust guide 10. As a result, there is no need to make a large gap between the contact base 8 and the exhaust guide 10, so gas leakage therefrom is reduced, gas blowing to the arc is further strengthened, and interrupting performance is improved. In this embodiment as well, the heat puffer chamber includes the nozzle 5,
Because it is surrounded by the contact cover 7 and heat-resistant material 13,
The same effect can be achieved because less thermal energy flows out of the thermal puffer chamber and the arc energy is effectively used to heat the gas. Further, as in the case of the third embodiment of the present invention shown in FIG. 4, the weight of the movable part is reduced, so that the operating force can be reduced.

[0016]

[Effects of the Invention] In the present invention, since the contact base is constructed of a combination of a lightweight material such as aluminum, which has a lower thermal conductivity than copper, and a heat-resistant material such as aluminum oxide, or an arc-resistant material such as copper-tungsten, The thermal puffer chamber is constructed of an insulating nozzle, a contact cover, and lightweight or heat-resistant materials, which reduces heat conduction on the walls of the thermal puffer chamber and allows the arc energy to effectively heat the gas, reducing the gas pressure. increases, and interrupting performance improves.

[0017] Furthermore, by constituting the contact base mainly of lightweight material, the weight of the movable part of the double flow heat puffer gas circuit breaker that drives the heat puffer chamber side is reduced, so that the operating force can be reduced. Therefore, in order to obtain the same shutoff speed, a smaller operating force is required, making it possible to use lower class operating equipment or replacing air operating equipment with spring operating equipment, resulting in economical improvements. A gas circuit breaker can be realized.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a blocking section showing one embodiment of the present invention.

FIG. 2 is an enlarged view of the blocking section in FIG. 1.

FIG. 3 is a longitudinal cross-sectional view of a blocking section showing a second embodiment of the present invention.

FIG. 4 is a longitudinal cross-sectional view of a blocking section showing a third embodiment of the present invention.

FIG. 5 is a vertical cross-sectional view of a blocking section showing a fourth embodiment of the present invention.

FIG. 6 is a vertical cross-sectional view showing a conventional double-flow thermal puffer type gas cutoff section in a closed state.

FIG. 7 is a vertical cross-sectional view showing a state of a conventional double-flow thermal puffer type gas cut-off section in the early stage of a cut-off operation.

FIG. 8 is a vertical cross-sectional view showing a state of a conventional double-flow thermal puffer type gas cut-off section in the latter half of the cut-off operation.

[Explanation of symbols]

2... Fixed contact, 5... Nozzle, 6... Movable contact, 7... Contact cover, 8... Contact base, 9... Conductive rod, 10... Exhaust guide, 11... Arc, 12... Lightweight material,
15...Exhaust channel, 16...Exhaust channel opening, 17...Exhaust guide opening, 18...Heat puffer chamber.

Claims (2)

[Claims] 1. A container filled with arc-extinguishing gas includes an insulating nozzle surrounding the contact portion of a pair of separable contacts, a cylindrical member to which the insulating nozzle is attached, and a puffer chamber; A gas circuit breaker is provided with an exhaust passage for discharging the gas in the puffer chamber to a surrounding gas space in the container through a contact portion, and the exhaust passage is connected to the contact provided inside the insulating nozzle. is formed in the cylindrical member to extend substantially in the radial direction of the contact, and closes and shuts off the exhaust port on the ambient gas space side of the exhaust flow path in the early stage of the shutoff operation in connection with the shutoff operation. In the gas circuit breaker in which an exhaust guide that opens in the latter stage of operation is slidably provided with the cylindrical member, the cylindrical member is made of a combination of a material with a thermal conductivity lower than that of copper and a heat-resistant material. Characteristic gas circuit breaker. 2. The gas circuit breaker according to claim 1, wherein the material constituting the cylindrical member having a thermal conductivity lower than that of copper is a material lighter than copper.