JP2523675B2 - Puffer type gas circuit breaker - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a buffer type gas circuit breaker, and more particularly to a circuit breaker structure suitable for downsizing.

[Conventional technology]

2. Description of the Related Art In recent years, with the improvement of the breaking performance of the buffer type gas circuit breaker, the size and the size of the circuit breaker have been greatly reduced. Along with this, the size of the buffer cylinder, which greatly affects the shutoff performance, is being reduced, but the narrowing of the inside of the cylinder causes
There is a problem that the machining becomes difficult. These solutions have the method of manufacturing by dividing the buffer cylinder,
For example, it is disclosed in Japanese Utility Model Publication Nos. 61-54650, 61-166430, and 53-78465.

 Hereinafter, an example of the related art will be described with reference to the drawings.

3 to 5 show the shut-off portion of the buffer type gas circuit breaker in the closed state.

The cutoff operation will be briefly described. By driving the buffer cylinder 1 to the right in the figure by an operating device (not shown),
The gas in the buffer chamber 3 formed by the buffer cylinder 1 and the fixed piston 2 is compressed. The arc generated between the movable arc contact 5 and the fixed arc contactor 4 which is separated along with the operation is extinguished by being blown with the high pressure gas guided by the air supply port 6 and the insulator nozzle 7. Here, 8 is a fixed main contactor, 9 is a movable main contactor, and 10 is an exhaust port. Also,
The buffer cylinder 1 includes an end plate portion 1a, a cylinder portion 1b, and a slot portion 1c.

The buffer cylinder 1 in the conventional example is constructed by dividing the space between the end plate portion 1a and the cylinder portion 1b in FIGS. 3 and 5, and between the end plate portion 1a and the rod portion 1c in FIG. By dividing in this way, the inner surface of the cylinder can be machined even if the diameter of the buffer cylinder 1 is significantly reduced.

[Problems to be solved by the invention]

However, the above-mentioned conventional example does not consider the influence on the breaking performance, the energizing performance and the mechanical performance due to the drastic downsizing of the buffer cylinder 1, and has the following problems.

FIG. 6 is a perspective view showing an example of the buffer cylinder 1 which has been drastically reduced in size (reduced in diameter).

By reducing the diameter of the buffer cylinder 1, the area of the end 1b is reduced. On the other hand, since the strength of the action of spraying the arc, that is, the area of the air supply port 6 that determines the breaking performance cannot be reduced, there arises a problem that the current-carrying area at the end face 1b cannot be sufficiently secured. In such a situation, Figs. 3 and 4
In the method of dividing by the end plate portion 1a shown in the figure, the energization performance at the contact surface may not be satisfied.

An example of solving the problem in terms of securing the energizing area is to fix the end plate portion 1a and the cylinder portion 1b with a screw provided on the inner circumference of the cylinder, as shown in FIG. By increasing the axial length of the screw part, the necessary energizing area can be obtained. However, with such fixing with an annular screw, there is a drawback that the circuit breaker is loosened when the breaker is operated, for example, when the main contactors 8 and 9 are applied and the impact is directly applied to the screw part to cause distortion. There was a problem with. The looseness may cause heat damage to the screw.

An object of the present invention is to reduce the size of a circuit breaker by dividing the buffer cylinder without adversely affecting the breaking performance, energizing performance and mechanical performance under the condition that the diameter of the packing cylinder is significantly reduced. It is in.

[Means for solving problems]

A puffer type gas circuit breaker that achieves the above object is a puffer cylinder formed of an end plate part, a cylinder part and a rod part, a fixed piston slidable in the puffer cylinder, and a movable arc contactor fixed to the end plate part. When,
A fixed arc contact that is separable from the movable arc contact,
In a buffer type gas circuit breaker comprising an insulator nozzle that surrounds the movable arc contact and is fixed to the end plate portion by a fixing metal fitting, a large diameter larger than the outer diameter of the cylinder portion on the outer periphery of the end plate portion. A portion is provided so that the end plate portion and the cylinder portion can be divided by the large diameter portion, and the end plate portion and the cylinder portion are divided into a plurality of first portions.
And the end plate portion and the cylinder portion are fixed with a plurality of second bolts.

[Action]

By providing a large-diameter part, a sufficient current-carrying area can be secured,
Since the area of the air supply port provided on the end plate can be set to the same as the conventional one, it does not affect the blocking performance. Also, since it can be fixed with bolts, deterioration of mechanical performance can be prevented.

〔Example〕

FIG. 1 shows a shutoff portion of a buffer type gas circuit breaker which is an embodiment of the present invention.

A large diameter portion larger than the outer diameter of the cylinder portion 1b was provided on the outer periphery of the end plate portion 1a, and the end portion 1a and the cylinder portion 1b were divided by this large diameter portion. The divided portion is fixed by a fixing bolt 11 for the movable main contactor 9 which also serves as a fixing member for the insulator nozzle 7, and a bolt 12 for fixing the end plate portion 1a and the cylinder portion 1b.

FIG. 2 shows a perspective view of the buffer cylinder 1 in FIG. Here, 13 is a hole for the bolt 11, and 14 is a screw hole for fixing the movable arc contact 5.

In this way, by providing a large-diameter portion on the outer periphery of the end plate portion 1a and dividing the end plate portion 1a, the energized area of the divided portion can be secured, and the air supply port 6 can be secured.
Since the area of can be set to the same as the conventional one, it is possible to prevent the blocking performance from being adversely affected. Also bolts 11,1
Since the divided part can be securely fixed by 2, the mechanical impact force at the time of insertion is not applied to the screw part as in the conventional example, and a blocking part with high mechanical reliability with no looseness of the contact part is provided. can get.

Besides, the following advantages can be obtained by separately installing the bolt 11 for fixing the movable main contact 9 and the bolt 12 for fixing the end plate portion 1a and the cylinder portion 1b.

Bolts 12 that fix only the split parts of the buffer cylinder 1
Since the movable arc contactor 5, the insulator nozzle 7 and the like are disassembled and inspected and reassembled, the bolt 11 can be removed and attached, which is the same as when the conventional buffer cylinder is integrally formed. On the other hand, for example, in the conventional example shown in FIG. 4, by removing the movable arc contactor 5, the end plate portion 1a and the cylinder portion 1b also come off from the rod portion 1c, and it takes time to reassemble. It was

〔The invention's effect〕

According to the present invention, even if the diameter of the buffer cylinder is significantly reduced, the buffer cylinder can be configured without adversely affecting the breaking performance, the energizing performance, and the mechanical performance, so that the circuit breaker can be downsized. .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partial longitudinal sectional view of a buffer type gas circuit breaker according to an embodiment of the present invention, FIG. 2 is a perspective view of the buffer cylinder of FIG. 1, and FIGS. FIG. 1 is a partial vertical cross-sectional view of a conventional buffer type gas circuit breaker, and FIG. 6 is a perspective view of a buffer cylinder showing a miniaturized example. 1 …… Puffer cylinder, 1a …… End plate part, 9 …… Moveable main contactor, 11,12 …… Bolt.

Front page continuation (72) Inventor Yukio Kurosawa 4026 Kuji Town, Hitachi City, Ibaraki Prefecture Hitachi Research Laboratory, Hitachi Ltd. (56) Reference JP 62-93826 (JP, A) JP 58-165231 (JP) , A) Actual development Sho 55-108635 (JP, U)

Claims (1)

(57) [Claims] 1. A buffer cylinder formed of an end plate portion, a cylinder portion and a rod portion, a fixed piston slidable in the buffer cylinder, a movable arc contact fixed to the end plate portion, and the movable arc contact. In a buffer type gas circuit breaker comprising a fixed arc contactor that is separable from the movable arc contactor, and an insulator nozzle that surrounds the movable arc contactor and is fixed to the end plate portion by a fixing bracket, the outer periphery of the end plate portion. Providing a large diameter portion that is larger than the outer diameter of the cylinder portion,
The end plate portion and the cylinder portion are configured to be divided by the large-diameter portion, the end plate portion and the cylinder portion are fixed by a plurality of first bottles, and the fixing metal fittings are A buffer type gas circuit breaker characterized in that an end plate portion and the cylinder portion are fixed by a plurality of second bolts.