JPH01167920A - Arc gas exhaust device - Google Patents

Abstract

PURPOSE:To cause the elastic deformation of a dust cover from the folding part thereof on gas pressure and improve exhaust efficiency by engaging the folding part with the support part of an exhaust port. CONSTITUTION:A folding part 5 is formed on a dust cover 1 comprising an elastic board in a thickness wise direction, and a body case 2 is provided with a support part 5 for engaging the folding part 3 with an exhaust port 4 to be closed with the cover 1. And when a rated current is flowing at a contact point part 7, a small exhaust port 19 is closed due to the elasticity of the cover 1, and the exhaust port 4 is closed with an exhaust board 18, thereby preventing an ingress of foreign materials from the exhaust port 4. On the other hand, the contact point part 7 opens upon occurrence of shortcircuit and an arc and arc gases are generated between a movable contact point 0 and a fixed contact point 8. And when arc gas pressure increases, the cover 1 undergoes elastic deformation and moves away from the exhaust board 18, thereby releasing the small port 19 and causing the exhaust of arc gases Q outside through the exhaust port 4.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an arc gas exhaust device applied to a circuit breaker or the like.

[Background technology]

FIG. 7 shows a conventional example. That is, this arc gas exhaust device is applied to a three-pole circuit breaker, and is composed of a lower case 50 and an upper case 51, a main case 53 having an exhaust hole 52 at the joint part, and a dustproof cover 54. has been done. A vertical groove 455 is formed on the opposing side surface of the exhaust hole 52, and engaging ears 54a on both sides of the base end side of the dustproof cover 54 engage with this vertical groove 55. The dustproof cover 54 is formed of an elastic plate, and has a folded part 54b in the thickness direction at the base end.
The end of the exhaust plate 56 having the small exhaust hole 56a engages with the folded portion 54b.

The exhaust hole 52 is closed by an exhaust plate 56, and the small exhaust hole 56a is closed by a dustproof cover 54, which prevents foreign matter from entering from the outside and prevents poor contact between contacts (not shown) inside the main body case 53. Preventing occurrence. Then, when the short circuit is broken, an arc is generated at the contact part and arc gas is generated to increase the arc gas pressure, and the dustproof cover 54 is pushed through the small exhaust hole 56a, and the dustproof cover 54 is elastically deformed outward and is exhausted at the same time.

However, this arc gas exhaust device does not have a dust cover 54.
The part that elastically deforms due to the arc gas pressure is the retaining lug 54.
It is useless to form the small exhaust hole 56a in the part of the exhaust plate 56 facing the retaining lug 54a, and the dust cover 54 is not able to be exhausted effectively because the amount of the dust cover 54 is too small to fall down. Since the exhaust opening area cannot be made large,
The disadvantage was that the exhaust volume could not be increased, resulting in poor exhaust efficiency. As a result, the arc gas pressure increases, causing deterioration of the internal insulation, and in order to avoid this, it was necessary to increase the size of the equipment.

Further, when a large current is cut off, the arc gas pressure further increases, causing the engagement lug 54a to come off from the vertical groove 55, resulting in problems such as foreign matter intervening in the contact portion and poor contact.

[Purpose of the invention]

An object of the present invention is to provide an arc gas exhaust device that can improve exhaust efficiency.

[Disclosure of the invention]

The arc gas exhaust device of the present invention includes a dustproof cover formed of one elastic plate and having a folded part folded back in the thickness direction of the elastic plate at one end of the elastic plate, and an exhaust hole that is closed by the dustproof cover. The main body case is provided with a support portion that locks the folded portion in the exhaust hole.

According to the configuration of the present invention, the support part is provided in the exhaust hole, and the folded part of the dustproof cover is engaged with the support part, so that the dustproof cover can be elastically deformed from the folded part by arc gas pressure. Therefore, the opening area of the exhaust hole can be increased when arc gas is generated, and therefore the exhaust efficiency can be improved. Furthermore, even if the arc gas pressure increases, the support part is locked to the folded part of the dustproof cover, so it will not come off.

Embodiment A first embodiment of the present invention will be described with reference to FIGS. 1 to 4. That is, this arc gas exhaust device consists of a dustproof cover 1 and a main body case 2.

The dustproof cover 1 is formed of an elastic plate, and a folded part 3 that is folded back in the thickness direction of the elastic plate is formed at one end of the dustproof cover 1.

The main body case 2 has an exhaust hole 4 that is closed by the dustproof cover 1, and is provided with a support portion 5 that locks the folded portion 3 to the exhaust hole 4.

The main body case 2 is applied to a three-pole circuit breaker, and consists of a lower case 6a and an upper case 6b, and an exhaust hole 4 is formed in the joint portion thereof.

The contact portion 7, which serves as an arc generation source, is composed of a fixed contact 10 and a movable contact 11, each having a fixed contact 8 and a movable contact 9 that are in mutual contact with each other. The contact portion 7 is provided with three poles, each of which is isolated within the main body case 2. The fixed contact 10 integrally forms a power supply side terminal plate 12. The opening mechanism 13 communicates with each movable contact 11 and closes the movable contact 1 when an abnormal current such as an overcurrent or short-circuit current flows through the contact portion 7.
1 from the fixed contact 8. The handle 14 is connected to the opening mechanism 13, and its upper portion protrudes from the top surface of the main body case 2.
In addition to normal on/off operations, the movable contact 9 is returned to its original state of contacting the fixed contact 8 after being separated during an overcurrent or short circuit accident. 20 is a load side terminal, and 21 is a lead wire connecting the load side terminal 20 and an abnormal current detection section (1'M not shown) of the contact opening mechanism 13.

A power supply side terminal plate 12 is disposed on the lower surface of the exhaust hole 4.

15 is a terminal screw, and 16 is a washer.

Further, a vertical groove 17 is formed on the opposite side of the exhaust hole 4, and the side of the exhaust plate 18 engages with this vertical groove 17, the lower end approaches the power supply side terminal plate 12, and the upper end is closed to the upper case 6b. It will be stopped from coming out. The exhaust plate 18 has a large number of exhaust holes 19, which are larger than the conventional example, formed on the side opposite to the power supply side terminal plate 12, and the end of the exhaust plate 18 on the side of the power supply side terminal plate 12 is used as an embodiment of the support part 5. There is. The outer surface of the folded part 3 of the dustproof cover 1 comes into contact with the power supply side terminal 12, and the supporting part 5 is engaged with the folded part 3, thereby holding the dustproof cover 1. and closes the small exhaust hole 19.

In this arc gas exhaust device, the exhaust hole 19 is normally closed by the elasticity of the dustproof cover 1 while the rated current is flowing through the contact portion 7, and the exhaust hole 4 is closed by the exhaust plate 18. It is possible to prevent foreign matter from entering through 4.

On the other hand, for example, when a short circuit occurs, the contact part 7 opens, an arc is generated between the movable contact 9 and the fixed contact 8, and at the same time arc gas is generated. When the arc gas pressure increases, the dust cover 1 is pushed through the small exhaust hole 19. Then, the dustproof cover 1 is elastically deformed and separated from the exhaust plate 1, and the small exhaust hole 19 is opened as shown in FIG.

Therefore, the arc gas Q is exhausted from the small exhaust hole 19 to the outside through the exhaust hole 4 due to its pressure. When the arc gas pressure decreases and the restoring force of the dustproof cover 1 becomes stronger, the dustproof cover 1
returns to contact the exhaust plate 18 and close the exhaust hole 19 again.

According to this embodiment, the support part 5 is provided in the exhaust hole 4, and the folded part 3 of the dustproof cover 1 is locked to the support part 5, so that the dustproof cover 1 can be elastically deformed from the folded part 3 due to arc gas pressure. can. Therefore, the opening area of the exhaust hole 4 can be increased when arc gas is generated, and therefore the exhaust efficiency can be improved.

Further, even if the arc gas pressure increases, the support part 5 is locked to the folded part 3 of the dustproof cover 1, so that it will not come off. As a result, the insulation state within devices such as circuit breakers is less susceptible to deterioration, and the devices can be made smaller.

In addition, in this embodiment, the folded part 3 of the dustproof cover 1 is located on the side of the power supply side terminal plate 12, and the arc gas Q is exhausted in the direction away from the power supply side terminal plate 12. It is possible to prevent an inter-electrode short circuit between the terminal plates 12.

Furthermore, since this embodiment has a configuration in which only the folded portion 3 of the dustproof cover 1 is locked to the support portion 5, the configuration is simple and the cost can be reduced.

A second embodiment of the invention is shown in FIG. That is, in the first embodiment, this arc gas exhaust device has one exhaust hole 19a formed in the center of the exhaust plate, and a reinforcing portion 22 such as a rib or beading is provided on the dustproof cover 1 to improve the dustproof cover. The elastic force of 1 is reinforced. This embodiment has a large breaking capacity and is therefore effective when the arc gas pressure is large, and prevents the dust cover 1 from falling too far and causing arc gas to be exhausted near the power supply side terminal board 12 side, resulting in a short circuit between poles. can do. Further, depending on the shape and size of the reinforcing portion 22, an optimal tilting angle of the dustproof cover 1 can be realized using the same material.

In addition, although the reinforcement part 22 is provided on the inner surface side of the dustproof cover 1 in the said Example, it may be provided on the outer surface side.

A third embodiment of the invention is shown in FIG. That is, in this arc gas exhaust device, the support part 5 of the υ toss hole 4 is integrally formed on the upper case 6b side of the main body case 2 and hangs down, and the exhaust plate 4 can be omitted and the number of parts can be reduced. can.

Although the main body case 2 of the above embodiment has a three-pole structure, the number of poles may be one or more.

〔Effect of the invention〕

According to the arc gas exhaust device of the present invention, the support portion is provided in the exhaust hole, and the folded portion of the dustproof cover is engaged with the support portion, so that the dustproof cover can be elastically deformed from the folded portion due to the arc gas pressure.

Therefore, the opening area of the exhaust hole can be increased when arc gas is generated, and therefore the exhaust efficiency can be improved. Further, even if the arc gas pressure increases, the support part is locked to the folded part of the dustproof cover, so it does not come off.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view of the first embodiment of the present invention, Fig. 2 is a schematic sectional view of a circuit breaker, Fig. 3 is a schematic plan view thereof, and Fig. 4 is a partial sectional view of the arc gas exhaust device in its operating state. , FIG. 5 is a perspective view of essential parts of the second embodiment, FIG. 6 is a cutaway side view of the third embodiment, and FIG. 7 is an exploded perspective view of the conventional example. DESCRIPTION OF SYMBOLS 1... Dustproof cover, 2... Main body case, 3... Folded part, 4... Exhaust hole, 5... Support part 13 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 1. 1. Patent Application No. 332881 of 1988 2. Name of the invention Arc gas exhaust device 3. Relationship with the person making the amendment Applicant 4. Agent (1) Page 3, line 12 of the specification In line 13, the phrase "because the arc gas pressure increases" is corrected to "as the arc gas pressure increases." (2) Page 3 of the specification, lines 16 to 17, “Vertical groove 55
The phrase "comes off from the vertical groove 55 and becomes a contact" is corrected to "comes off from the vertical groove 55 and does not return to its original position, so the small exhaust hole 56a is opened and becomes a contact." (3) On page 3, line 20 of the specification, the phrase "exhaust efficiency can be improved" has been replaced with "exhaust efficiency and contact reliability can be improved"
I am corrected. (4) Lines 14 to 16 of page 4 of the specification, page 3 of page 8
Lines 5 to 7, page 10, lines 5 to 7, ``Even if the arc gas pressure increases, the dust-proof cover...
The statement "will never come off" has been corrected to read "Even if the arc gas pressure increases, the dust cover always returns to its original position and closes the small exhaust hole, so no foreign objects can enter the contact area." (5) In lines 5 to 6 of page 8 of the specification, the phrase "insulating state within the device" is corrected to "the pressure inside the device is reduced and is also in an insulating state." (6) On page 9, line 10 of the specification, the phrase "may be provided" is corrected to "may be provided. Also, the number of exhaust holes does not need to be one."

Claims (3)

[Claims] (1) A dustproof cover formed of an elastic plate and having a folded part folded in the thickness direction of the elastic plate at one end of the elastic plate, and an exhaust hole that is blocked by the dustproof cover, and the folded part is folded to the exhaust hole. An arc gas exhaust device comprising a main body case provided with a support part for locking the parts. (2) The exhaust hole has a pair of grooves on opposite sides of the exhaust hole, both sides of the exhaust plate having the small exhaust holes engage with the grooves, and the supporting portion is formed at the end of the exhaust plate. An arc gas exhaust device according to claim (1). (3) The arc gas exhaust device according to claim (1), wherein the dustproof cover has a reinforcing portion for reinforcing elastic force.