JPS6029792Y2 - circuit break - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a circuit breaker for wiring which improves the breaking performance by blowing air into the arc extinguishing chamber when opening the circuit.

In conventional circuit breakers, the arc generated between the fixed and movable contacts during opening is stretched and extinguished by the induced magnetic field of a magnetic plate provided in the arc extinguishing chamber.

There is also a type that has a current limiting effect by performing a storage speed cutoff operation by electromagnetic repulsion of fixed and movable circumferential contacts.

However, recent circuit breakers are required to be smaller and have better performance, and as the size of the circuit breaker progresses, the volume of the arc extinguishing chamber becomes smaller. is becoming a problem.

The present invention has been developed to solve the above problems, and is designed to provide a power supply surrounded by the walls of the case across the path through which the movable contact moves between the arc extinguishing chamber and the operating mechanism in the breaker. An air chamber is formed, and blades are provided in this air supply chamber that move in a direction that moves toward each other when the contact is opened in conjunction with a movable contact. By blowing into the arc extinguishing chamber, the cooling effect on the arc is enhanced, improving the breaking performance and reducing thermal damage to the circuit breaker.

Embodiments of the present invention will be described below with reference to the drawings.

1 to 6 are views showing one embodiment of the present invention, in which a fixed contact 1 is fixed to a case 3, and a movable contact 2 is a fulcrum pin 6 on a movable arm 5 of an operating mechanism section 4. installed on.

The contact portion between the fixed contact 1 and the movable contact 2 is placed in an arc extinguishing chamber 8 formed between the case 3 and the cover 7, and the movable contact 2 moves between the arc extinguishing chamber 8 and the operating mechanism section 4. They are connected by passage 9.

The movable contactor 2 is constantly applied with contact pressure by a spring 10 with a small spring constant, and when a large current such as a short-circuit current flows in the electrical circuit, the movable arm 5 of the operating mechanism section 4 is fixed before tripping. Due to the electromagnetic repulsion force acting between the movable liquid contactors 1 and 2, the movable contactor 2 separates from the fixed contactor 1 as shown by the chain line in Fig. 1 to perform a current-limiting cutoff, which occurs at the contact portion. The arc is caused by a magnetic plate 11 provided in the arc extinguishing chamber 8.
It is stretched by the induced magnetic field and receives arc extinguishing action.

The case 3 is formed with an air supply chamber 12,12' surrounded by a wall of the case across the passage 9.

The blades 13.13' provided in the air supply chamber 12.12' are restricted from vertical movement by the case 3 and the cover 7, and are parallel to the movable contact 2 as shown in detail in FIG. They are connected via quadrilateral links 14 and 14', and each link connection portion is provided with an appropriate margin so as not to interfere with the opening/closing operation of the movable contact 2.

This parallelogram link 14.14' acts as an interlocking mechanism that converts the vertical movement of the movable contactor 2 into a horizontal movement perpendicular to the plane of movement and transmits it to the blade 13.13'. Since the two sets of parallelogram links 14.14' are formed symmetrically, the two blades 13.13'
The directions of motion are opposite to each other.

That is, when the movable contactor 22 is in the closed circuit position, the parallelogram link 14.14' approaches the horizontal position, as shown in FIG.
It is located at the farthest position within 12'.

When the movable contactor 2 moves upward from this state as shown by arrow A in FIG. 4, the parallelogram link 14.1
4' is bent, and the blades 13.13' move toward each other using the cover 7 as a stopper as shown by arrow B, and 0 parts of the air surrounded by the air supply chamber wall and the blade 13.13' is removed. Compress.

In reality, the movable contactor 2 opens and opens at an extremely high speed due to electromagnetic repulsion, so the air pressure in the 0 section increases rapidly.
This compressed air is blown into the arc extinguishing chamber 8 through an opening 15.15' on one side of the air supply chamber 12.12'.

Figure 5 shows the flow of air caused by the movement of the blades 13 and 13'.The air blown into the arc extinguishing chamber 8 reaches the contact area as shown by the arrow, cools the arc and extinguishes it. This has the effect of reducing the temperature inside the arc extinguishing chamber and reducing the wear and tear of contacts and deterioration of insulators.

At this time, in order to prevent the back of the blade 13.13' from being depressurized and reducing the arc blowing effect, the blade 13.13' is opened from the opening 16.16' provided on the opposite side of the air supply chamber 12.12'.
Let the air be sucked in behind it as shown by arrow E.

Note that a slit for passing the parallelogram link 14.14' through is provided in a part of the surrounding wall of the air supply chamber 12.12'.

As explained above, in the present invention, when the movable contact is opened, the air in the air supply chamber is compressed by the vanes that operate in conjunction with the movable contact, and the compressed air is blown into the arc extinguishing chamber, thereby promoting arc extinguishing. It is possible to keep the arc energy low, lower the temperature inside the arc extinguishing chamber, increase the breaking capacity, and reduce thermal damage to the breaker due to the arc. This is particularly effective in cases where

Moreover, since the air supply chambers 12 and 12' can be provided across the passage 9 using the dead space normally blocked by the walls of the case, there is no need to increase the size of the breaker.
There are advantages to implementing it.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of essential parts showing one embodiment of the circuit breaker according to the present invention; Fig. 2 is a plan view thereof; Figs. 3 and 4 are cut-away side views showing the relative positions of the movable contact and the blades. 5 is a plan view showing the flow of air when the electrodes are opened, and FIG. 6 is a detailed view of the interlocking mechanism. 1; Fixed contact, 2; Movable contact, 3; Case, 4; Operating mechanism section, 8; Arc extinguishing chamber, 9; Passage through which the movable contact moves, 12.12'; Air supply chamber, 13.13 '; Feather, 14,
14'; Parallelogram link as interlocking mechanism, 15.15
'; An opening for blowing air.

Claims (1)

[Scope of utility model registration request] An air supply chamber surrounded by the wall of the case is formed between the arc extinguishing chamber in the breaker and the operating mechanism section through which the movable contact moves. The circuit breaker is provided with blades that move toward each other when the electrodes are opened, and air is blown into the arc extinguishing chamber from the opening of the air supply chamber by the movement of the blades.