JPS5921489Y2 - Arc extinguishing device for circuit breakers and breakers - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an arc extinguishing device for improving the breaking performance of a circuit breaker.

In FIG. 1 showing the arc-extinguishing part of a circuit breaker provided with a conventional current wire ring, the current wire ring 1 is connected to a contactor when current flows from a power supply terminal 2 through a fixed contact 4 to a movable contact 3. When a short-circuit current flows by creating a magnetic flux in the vicinity and interlinking with the current flowing through the movable contact 3, a force is generated to advance the opening timing of the movable contact 3 and increase the opening speed.

Further, a force is generated to quickly pull the arc generated between the contacts toward the arc chute 7, thereby enhancing the current limiting effect of the circuit breaker and improving the breaker performance.

However, since the current wire ring 1 is connected to the power supply side terminal 2, the disconnection and connection also becomes a live part, and the stopper 5 of the movable contact 3, which is a metal body on the load side, and the opening/closing mechanism of the circuit breaker (not shown) The insulation distance from the frame 6 that supports it is small.

In particular, when a large current is cut off, the arc extinguishing chamber is filled with high-temperature ionized gas, which significantly reduces the insulation performance of the space.

For this reason, it is necessary to insulate the current wire ring 1, but conventionally, the current wire ring has been insulated by wrapping it with insulating tape or by applying insulation coating.

However, it takes time and effort to wind insulating tape, and it is difficult to wrap it well, especially around corners, resulting in poor insulation reliability.

In addition, insulating coating requires masking to prevent paint from adhering to electrical contact surfaces such as terminals 2 and contacts 4, which is time-consuming. Insulation reliability is poor due to uneven paint film thickness and pinholes between areas where it is difficult to adhere and other areas.

The present invention is designed to improve the arc extinguishing performance of a circuit breaker by simplifying and sufficiently insulating the current wire in a circuit breaker with a current wire, thereby reducing manufacturing costs and improving insulation reliability. An object of the present invention is to provide an arc extinguishing device for a circuit breaker that makes it possible to do this.

Embodiments of the present invention shown in the drawings will be described below.

In Fig. 2, 8 is a bag-shaped insulator made of a heat-resistant, arc-resistant insulator, and its materials include silicone rubber,
Possible materials include special polyester resins and phenolic resins.

The inner cavity of the bag-shaped insulator 8 has approximately the same shape as one side of the current wire ring, and after the current wire ring 1 is installed and fixed in the mold case 9 as shown in FIG. , when the mold cover 10 is attached, the bag-shaped insulator 8 is protected by the protrusion 11 integrally formed on the mold cover,
Make sure that the wire does not come out from the current wire ring 1.

In the arc extinguishing device of the present invention constructed in this way, the current wire ring can be insulated during the final assembly process, so the insulation work is simplified and the manufacturing process is simplified and economical.

Furthermore, since the thickness and dielectric strength of the insulation coating can be inspected when the bag-shaped insulator 8 is molded alone, insulation reliability is improved and loss due to defects is reduced.

Furthermore, since the thickness during molding can be easily controlled, sufficient thickness can be obtained especially at corners and edges where coating thickness is required.

In another embodiment shown in FIG. 4, the bag-shaped insulator 12 a
, 12b is divided into two parts, and a recess 1 into which the current wire ring 1 is inserted.
3a and 13b are provided, and the current wire ring 1 is installed as shown in FIG.
is attached so as to be wrapped around it from both sides, and fixed by a mold case 9 and an arc chute 7.

As described above, according to the present invention, as described above, the assembly process is simplified, yield is improved, productivity is improved, and insulation reliability is improved.

Furthermore, it is easier to select materials than insulating paint or tape, and even in structures that are particularly susceptible to arcing, it is possible to use inorganic materials such as zircon, which has good arc resistance, and has the advantage of expanding the range of applications. There is.

[Brief explanation of the drawing]

Figure 1 shows the arc extinguishing device of a conventional circuit breaker.
Fig. 2 is an exploded view showing the arc extinguishing device of the circuit breaker of the present invention, Fig. 3 is an assembled configuration diagram thereof, Fig. 4 is an exploded view showing another embodiment, and Fig. 5 is an assembled configuration diagram thereof. be. 1... Current wire ring, 3... Movable contact,
4... Fixed contact, 8... Bag-shaped insulator, 12 a, 12 b... Insulator.

Claims (2)

[Scope of utility model registration request] (1) An arc extinguishing device for a circuit breaker having a current wire ring that generates a blow-out magnetic flux, in which the current wire ring is covered with a bag-like insulator. (2) The arc extinguishing device for a circuit breaker according to claim 1, wherein the bag-shaped insulator is divided into two parts each having a recess into which a current wire is inserted.