JPH0641295Y2 - Arc gas exhaust device such as circuit breaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an arc gas exhaust device for a circuit breaker or the like applied to a circuit breaker or the like.

[Conventional technology]

FIG. 4 shows a conventional example. That is, this arc gas exhaust device such as a circuit breaker is applied to a circuit breaker for three poles, and includes an arc extinguishing chamber 53a having a lower case 50 and an upper case 51 and an exhaust passage 52 at a joint portion thereof. It is composed of a formed body case 53 and a dustproof cover 54. A vertical groove 55 is formed on the opposite side surface of the exhaust passage 52.
Engagement tabs 54a on both sides of the dust-proof cover 54 on the base end side are engaged with. The dust-proof cover 54 is formed of an elastic plate, has a folded-back portion 54b formed at the base end in the plate thickness direction, and the end of the exhaust plate 56 having the exhaust hole 56a engages with the folded-back portion 54b.

The exhaust passage 52 is closed by an exhaust plate 56, and the exhaust hole 56a is closed by a dustproof cover 54, which prevents foreign matter and the like from entering from the outside and causes contact failure in a contact portion (not shown) in the main body case 53. Is being prevented. Then, when a short-circuit is interrupted, an arc is generated in the contact portion (not shown), and when the arc gas is generated and the arc gas pressure becomes high, the dust cover 54 is pushed through the exhaust hole 56a and the dust cover 54 elastically deforms outward, At the same time, the arc gas is exhausted.

[Problems to be solved by the device]

However, in the arc gas exhaust device such as the circuit breaker, since the portion of the dust-proof cover 54 that is elastically deformed by the arc gas pressure is only on the tip side of the engaging ear piece 54a, the engaging ear piece 5
Forming the exhaust hole 56a in the portion of the exhaust plate 56 facing the 4a is wasteful, and since the dust cover 54 has a small amount of tilting, effective exhaust cannot be performed, and the exhaust opening area cannot be made large, thus exhausting. There is a drawback that the exhaust efficiency is poor because the amount cannot be increased. As a result, the arc gas pressure becomes high, and the internal insulation deteriorates, and it is necessary to upsize the equipment to avoid it.

Further, when the large current is cut off, the arc gas pressure is further increased, so that the engaging ear piece 54a is disengaged from the vertical groove 55, and foreign matter intervenes in the contact portion, resulting in poor contact.

Therefore, an object of the present invention is to provide a circuit capable of increasing the elastic deformation range of the dust cover, increasing the opening area of the exhaust hole, improving exhaust efficiency, and preventing the dust cover from falling too much when the arc gas pressure is large. An object is to provide an arc gas exhaust device such as a circuit breaker.

[Means for Solving the Problems]

In an arc gas exhaust device such as a circuit breaker according to the present invention, a folded-back portion for fixing the dust-proof cover is formed at the base end of the dust-proof cover by being locked to one edge of the exhaust plate.
The present invention is characterized in that a stopper for restricting the range of elastic deformation of the dustproof cover is provided on the tip end side of the dustproof cover.

[Action]

According to the arc gas exhaust device such as the circuit breaker of the present invention, since the folded portion for fixing the dust cover is formed at the base end portion of the dust cover, the dust cover can be elastically deformed from the folded portion by the arc gas pressure. Therefore, it is possible to increase the tilt of the dust-proof cover and increase the opening area of the exhaust hole, and thus improve the exhaust efficiency. Further, since the stopper for restricting the elastic deformation range of the dustproof cover is provided, it is possible to prevent the dustproof cover from falling too much even when the blocking capacity is large and the arc gas is high.

〔Example〕

A first embodiment of the present invention will be described with reference to FIGS. That is, the arc gas exhaust device such as the circuit breaker has the exhaust passage 3 of the arc extinguishing chamber 2 having the contact portion 1.
The main body case 6 in which the exhaust plate 5 with the exhaust hole 4 is provided in the exhaust passage 3 so as to close the exhaust passage 3, and the base end portion 7a is fixed to close the outer surface side of the exhaust hole 4 of the exhaust plate 5 and the contact portion 1 Exhaust hole 4 due to the pressure of the arc gas generated by the arc
In an arc gas exhaust device such as a circuit breaker having a dustproof cover 7 having a tip portion 7b elastically deformed in a direction away from the bent portion 7c for fixing the dustproof cover 7 by locking it at one end edge of the exhaust plate 5. Is provided at one end, and a stopper 8 for restricting the elastic deformation range of the dustproof cover 7 is provided.

The main body case 4 is applied to a three-pole circuit breaker, and is composed of a lower case 10 and an upper case 11, and an arc extinguishing chamber 2 having an exhaust passage 3 is formed at a joint portion thereof. The contact portion 1 serves as a source of arc generation, and is provided in the arc extinguishing chamber 2 and is composed of a fixed contact 15 and a movable contact 16 each having a fixed contact 13 and a movable contact 14 that make mutual contact. There is. The contact portion 1 is provided with three poles, and each of the contact portions 1 is arranged in parallel in the main body case 6 by being partitioned by a partition wall 10a. The fixed contactor 15 is integrally formed with a terminal plate 17 of a terminal 18 on the power supply side. The contact opening mechanism (not shown) is used for each movable contact.
The movable contactor 16 is separated from the fixed contact 13 when an abnormal current such as an overcurrent or a short-circuit current flows through the contact portion 1 connected to the fixed contact 13. In addition, the handle (not shown) of the contact opening mechanism projects from the upper surface of the main body case 6, and in addition to the normal on / off operation, the movable contact 14 separated during an overcurrent or short-circuit accident is fixed to the fixed contact 13
Return to the original state of contact with.

The exhaust passage 3 of the body case 6 has an exhaust plate 5 having an exhaust hole 4.
Is provided, and the terminal plate 17 is provided on the lower surface of the exhaust passage 3,
Further, a terminal screw 23 is screwed into the terminal plate 17 via a washer 24 to form a terminal 18. Reference numeral 19 is an outer conductor fixed to the terminal screw 23.

The exhaust plate 5 engages with a vertical groove 3a formed on the opposite side of the exhaust passage 3 at the side of the exhaust plate 5, and the lower end thereof approaches the terminal plate 17.

The dustproof cover 7 is integrally formed of a thermoplastic material by molding, and the outer surface of the folded portion 7c is pressed against the terminal plate 17. Therefore, in normal times, the exhaust plate 5 is in complete contact. In addition, notches for passing the stopper 8 on both shoulders of the tip portion 7b.
Forming the nineteen.

The stopper 8 is integrally formed with the dustproof cover 7, and the arc-extinguishing chamber 2 is passed from the tip portion 7b of the dustproof cover 7 through the notch 19 of the exhaust plate 5.
When the dustproof cover 7 is extended to the side and elastically deforms in a predetermined range, the dustproof cover 7 is locked to the exhaust plate 5 as shown by an imaginary line in FIG. The range of elastic deformation of the dustproof cover 7 is determined by the length of the stopper 8. Therefore, if there is a space in the relationship between the terminal screw 23 and the arc extinguishing chamber 2, the fall amount can be adjusted arbitrarily. it can.

In the arc gas exhaust device such as the circuit breaker, the exhaust hole 4 is normally closed by the elasticity of the dustproof cover 7 while the rated current is flowing through the contact portion 1, and the exhaust passage 3 is closed by the exhaust plate 5. Therefore, foreign matter can be prevented from entering through the exhaust passage 3.

On the other hand, for example, when a short circuit occurs, the contact portion 1 is opened, an arc is generated between the movable contact 14 and the fixed contact 13, and at the same time arc gas is generated. When the arc gas pressure increases, the dust cover 7 is pushed through the exhaust hole 2, The dustproof cover 7 is elastically deformed as shown by the imaginary line in FIG. 1 to separate from the exhaust plate 5, and the exhaust hole 4 is opened. The arc gas exiting the exhaust hole 4 is exhausted to the outside from the tip portion 7b of the dust cover 7. When the arc gas pressure decreases and the restoring force of the dustproof cover 7 is superior, the dustproof cover 7 returns,
The exhaust hole 4 is closed again by contacting the exhaust plate 5.

Further, when the cutoff capacity is large and therefore the arc gas pressure is large, the tilt angle of the dustproof cover 7 becomes large and the stopper 8 locks the exhaust plate 5, whereby the dustproof cover 7 is prevented from falling too much and falls. It is possible to prevent a short circuit between the electrodes due to the arc gas being filled in the vicinity of the terminal screw 23 due to the excess.

According to this embodiment, the folded portion for fixing the dustproof cover 7
Since 7c is formed on the base end portion 7a of the dustproof cover 7, the dustproof cover 7 can be elastically deformed from the folded portion 7c by the arc gas pressure, so that the dustproof cover 7 can be largely tilted and the opening area of the exhaust hole 4 can be increased. Can be increased, and therefore exhaust efficiency can be improved. Further, in order to regulate the range of elastic deformation of the dust cover 7, the stopper 8
By providing the above, it is possible to prevent the dust cover 7 from falling too much even when the breaking capacity is large and the arc gas is high.

Although the main body case 6 of the above-mentioned embodiment has a three-pole structure, the number of poles is arbitrary two or more. In addition, the stopper 8
Although provided on the dustproof cover 7, it may be provided on the main body case 6 including the exhaust plate 5.

[Effect of device]

According to the arc gas exhaust device such as the circuit breaker of the present invention, since the folded portion for fixing the dust cover is formed at the base end portion of the dust cover, the dust cover can be elastically deformed from the folded portion by the arc gas pressure. Therefore, it is possible to increase the tilt of the dust-proof cover and increase the opening area of the exhaust hole, and thus improve the exhaust efficiency. Further, since the stopper for restricting the elastic deformation range of the dustproof cover is provided, it is possible to prevent the dustproof cover from falling too much even when the blocking capacity is large and the arc gas is high.

[Brief description of drawings]

1 is a sectional view of an essential part of an embodiment of the present invention, FIG. 2 is a sectional view taken along the line II-II, FIG. 3 is an exploded perspective view of a dust cover and an exhaust plate, and FIG. 4 is an exploded view of a conventional example. It is a perspective view. 1 ... Contact part, 2 ... Arc extinguishing chamber, 3 ... Exhaust passage, 4 ...
Exhaust hole, 5 ... Exhaust plate, 6 ... Main body case, 7 ... Dust cover, 7a ... Base end, 7b ... Tip part, 7c ... Folded part, 8 ... Stopper

Claims (1)

[Scope of utility model registration request] 1. A main body case in which an exhaust plate with an exhaust hole is provided in the exhaust passage so as to close an exhaust passage of an arc extinguishing chamber having a contact portion, and a base end portion of which is fixed to the exhaust plate. In an arc gas exhaust device such as a circuit breaker equipped with a dustproof cover having a tip portion that elastically deforms in a direction away from the exhaust hole by the pressure of arc gas generated by the arc generated at the contact portion while closing the outer surface side of the hole,
A fold-back portion for fixing the dust-proof cover is formed on the base end portion by engaging with one end edge of the exhaust plate, and a stopper for restricting an elastic deformation range of the dust-proof cover is provided on the tip end side of the dust-proof cover. An arc gas exhaust device for circuit breakers, etc.