JPS60101826A - Buffer type gas breaker - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a shutoff section of a buffer type gas circuit breaker, and particularly,
The present invention relates to a structure for fixing a main body of a movable contactor or a movable side shield to a buffer piston.

[Background of the invention]

Buffer type gas circuit breakers have excellent breaking performance and are the mainstream circuit breakers in ultra-high pressure systems.

A buffer type gas circuit breaker compresses the buffer chamber almost simultaneously with the opening operation of the contacts, and extinguishes the arc (2) by spraying the resulting high-pressure arc-extinguishing gas onto the arc (2) generated between the contacts. Therefore, it requires great operating power.

Therefore, the link system and contact device from the operation panel to the cut-off section are designed to withstand strong operating force.

FIG. 1 shows the shut-off state of a conventional buffer type gas circuit breaker. The current flows through the fixed contact 1, the movable contact 2, and the buffer shaft 3 to other terminals not shown.

The buffer chamber 50 includes a fixed piston 4 and a buffer cylinder.
Consists of 5. When the buffer shaft 3 is driven to the right by an operator (not shown) in response to a cutoff command, the buffer chamber 50 is compressed, and after moving a predetermined distance, the fixed contact 1 and the movable contact 2 are separated, causing a gap between the electrodes. An arc occurs. This arc is caused by arc-extinguishing high-pressure gas obtained by further compressing the buffer chamber 50 through the air supply hole 6. The shutoff is completed by being sprayed through the nozzle 7 and extinguishing the arc.

Here, the cover 8 forms a gas flow path, and the spring 9 applies contact force to the movable contact 2. Also, the nozzle 7 is attached to the nozzle holder 1.
0 is fixed by attaching it to the pant (3) a cylinder 5 with a plurality of bolts 11. FIG. 2 is a view from the ■-■ arrow in FIG. 1.

The closing operation is performed by driving the buffer shaft 3 in the opposite direction to the closing direction using an operating device (not shown) to restore the state shown in FIG. 1 and enable current to flow.

The test is called a switching test, in which the breaking and closing operations are performed without applying current or voltage to the circuit breaker.The standard is to perform 500 consecutive openings and closings to determine the opening time, closing time, switching speed, etc. It is specified that there are no abnormalities in various characteristics. Manufacturers usually conduct durability tests 10,000 times to increase reliability.

Therefore, the mechanical strength of each part must be sufficiently large. For example, the bolt 11 shown in FIG. 1 uses eight bolts as shown in FIG. 2, and is designed so that it can withstand two -2 bolts. However, if the opening/closing operation is continued with the loosened part, in the worst case, it may fall, causing problems with insulation, and if it falls while interrupting a large current, there will be a problem that the desired breaking performance will not be obtained.

[Purpose of the invention]

(4) An object of the present invention is to provide a blocking structure that prevents the bolt from falling even if the bolt loosens.

[Summary of the invention]

The present invention is characterized by a recess that accommodates the head of a bolt used for fixing to the buffer cylinder, and a tool insertion hole having a smaller diameter than the head.

(Embodiment of the Invention) Hereinafter, an embodiment of the present invention will be described based on the drawings. 6 Figure 3 shows the closed state of the buffer type gas circuit breaker shut-off section of the present invention. The nozzle holder 10a has a tool insertion hole. 21, the diameter of which is smaller than the head diameter of the bolt 11.The nozzle holder 10a and tab are fixed by bolts 22.The bolts 21 and 22 are arranged alternately as shown in FIG.

The nozzle holders 10a and 10b are fixed with bolts 22, with the head of the bolt 11 housed in the four parts of the nozzle holder lOa. The bolt 11 is in a rotatable state (5). Next, the movable contactor 2 is attached to the buffer cylinder 5 with bolts 12, and the cover 8 and nozzle 7 are
As shown in FIG. 3, press the nozzle holder 10a.

The bolt 11 is fitted into the inner diameter of the tab, the tool is inserted through the tool insertion hole 21, the bolt 11 is rotated, and the bolt 11 is fixed to the buffer cylinder 5. Since the bolts 11 have little play, it is important to tighten them evenly. A socket bolt may be used as the bolt 11, or a recessed portion matching the shape of the tool may be provided in the head of the hexagonal bolt.

That is, even if the bolts 12.22 become loose due to multiple opening and closing operations, the heads of the bolts 12. Or, since it is closed by the buffer cylinder 5, it will not fall. Furthermore, it is impossible for all of the bolts 11 to loosen. If several bolts are loose, replace bolt 1 as shown in Figure 5.
Since the head diameter D2 of the bolt 1 is larger than the diameter of the tool insertion hole 21, the head end face will not loosen beyond the distance where it comes into contact with the bolt insertion hole. Therefore, the bolts 11°12. shown in FIG.
No. 22 will not fall, and insulation problems and deterioration of breaking performance due to falling (6) can be avoided.

Another embodiment of the invention is shown in FIG. That is, the present invention can also be applied to the case where the electric field mitigation shield 31 is attached to cover the nozzle holder 10. In addition, in Fig. 3, when the current carrying capacity is large, the nozzle holder 10a is also used as the movable contact body, and the fixed contact body is installed at a location corresponding to the nozzle holder 10a on the outer periphery of the fixed contact l. You can also do that.

〔Effect of the invention〕

According to the present invention, even if several bolts among the plurality of bolts that fix the nozzle holding part phase etc. become loose due to multiple opening and closing operations, it is possible to obtain a blocking part in which the loosened bolts will not fall.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a shut-off part of a conventional buffer type gas circuit breaker, FIG. 2 is a view taken along the nn arrow in FIG. 1, and FIG. Figure 4 shows the TV-IV in Figure 3.
5 is a cross-sectional view of the nozzle fixing part in FIG. 3, and FIG.
The figure is a sectional view of a blocking portion of another embodiment (7) of the present invention. DESCRIPTION OF SYMBOLS 1... Fixed contact, 2... Movable contact, 4... Fixed piston, 5... Buffer cylinder-150... Buffer chamber, 7... Nozzle, IO... Nozzle holder, 11
... Bolt, 21... Tool insertion hole. Agent Patent Attorney Akio Takahashi (8)

Claims (1)

[Claims] 1. A buffer cylinder and a buffer piston, which have a fixed contact and a movable contact, and compress and spray arc-extinguishing gas from the arc generated when these surface contacts open during a breaking operation. A gas circuit breaker comprising a buffer chamber comprising a buffer chamber, a nozzle for spraying and guiding arc-extinguishing gas to the arc, and a nozzle holder and socket bolt for fixing the nozzle to the buffer cylinder, wherein the nozzle holder is separable. It is composed of a first annular body and a second annular body, and has a recessed portion between these two annular bodies for accommodating the head of the socket bolt that fits into the buffer cylinder; A buffer type gas circuit breaker characterized in that the one located on the contact side has a tool insertion hole smaller than the diameter of the socket bolt on the end face on the fixed contact side. 2. In the item described in claim 1, (1) the annular body located on the fixed contact side also serves as the main body of the movable contact, and the outer circumference of the fixed contact is A buffer type gas circuit breaker comprising a main body of the fixed contact at a location corresponding to a main body of the movable contact. 3. The buffer type gas circuit breaker according to claim 1, wherein the annular body located at the fixed contact among the two annular bodies is also used as a shield for mitigating an electric field.