JP2015204182A - breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a breaker facilitating the replacement and maintenance of a damaged and fouled portion at the inside of an arc-extinguishing chamber.SOLUTION: A breaker includes a pair of shielding side plates 17 equipped so as to be freely loaded and unloaded in and from an arc-extinguishing chamber 1 through a through hole 1A provided to an outer wall of the arc-extinguishing chamber, and preventing an arc generated during a shutoff operation from blowing out to both sides, the shielding side plates 17 being allowed to be replaced freely. Each shielding side plate 17 is provided with an engaging projection 17a at an outer end thereof and a band-like projection 17b on a longitudinal side face thereof, for positioning the shielding side plate 17.

Description

  The present invention relates to a circuit breaker used in a DC power circuit.

  As a conventional protective circuit breaker for a railway substation, there is a DC high-speed circuit breaker. Unlike the AC interrupt, the DC interrupt does not have a zero point of current, and therefore the arc voltage must be increased to the power supply current to interrupt the current limit. For this reason, in order to increase the arc voltage, the DC circuit breaker commutates the arc generated between the arc contacts to the arc runner placed above the contact point, and runs on the arc runner to extend or turn off the arc length. It leads to the grid placed at the top of the arc chamber. Then, it is necessary to increase the arc resistance by penetrating the arc guided to the grid, and the arc voltage is increased and maintained until the current is interrupted.

  On the other hand, a very high-temperature arc melts the contacts, arc runner, and arc extinguishing chamber, so that the arc extinguishing chamber side plate was damaged or fouled by metal vapor or carbide (soot) when the number of interruptions increased. When soiled, the insulation resistance may be reduced. If the arc extinguishing chamber side plate is fouled and the insulation resistance is lowered, the fouling portion breaks down, so that the arc does not run and the arc voltage does not rise, so that there is a risk of interruption failure. In order to prevent dielectric breakdown at the arc extinguishing chamber side plate, it is necessary to periodically perform maintenance to clean the contaminated part or replace the side plate.

Japanese Utility Model Publication No. 6-60944

In the conventional arc extinguishing chamber structure, for example, as shown in FIG. 15, an insulating plate 29 for preventing the arc from blowing out is provided below the arc extinguishing chamber so as to be freely inserted (arrow 28).
In addition, as shown in FIG. 16, simple confirmation has been performed by removing a part of the bolts to which the component parts are attached and rotating the main body upper portion 30 by the rotating metal fitting 31.
However, since the portion damaged or soiled by the arc is integrated with the arc extinguishing chamber, the space between the side walls on the arc extinguishing chamber side is narrow and cleaning is difficult. If the arc extinguishing chamber is used while it is damaged or soiled in this way, it may fail to shut off, so cleaning the arc extinguishing chamber during maintenance is indispensable.
When replacing a damaged or soiled part in a conventional arc extinguishing chamber structure, it is necessary to replace all components, including parts that are not related to damage or soiling. All the bolts that had to be removed had to be removed, which took time and money.

  It is an object of the present invention to obtain a circuit breaker that is easy to replace and maintain a damaged or soiled part in an arc extinguishing chamber.

  The circuit breaker according to the present invention is equipped with a pair of shielding side plates that are equipped to be freely inserted into and withdrawn from the through-hole provided in the outer wall of the arc extinguishing chamber, and that prevent the arc generated during the interruption operation from blowing out to both sides, The shield side plate is replaceable.

  According to the circuit breaker of the present invention, it becomes easy to replace only the parts that are easily damaged and fouled by the arc inside the arc extinguishing chamber and have a short life, and cleaning at the time of maintenance that does not require parts replacement is facilitated. Furthermore, parts are not replaced by the entire arc-extinguishing chamber, but only the shielded side plates, which are damaged and soiled, are replaced. This reduces work time and costs during maintenance, and makes maintenance easier. A circuit breaker can be obtained.

It is the front sectional view showing the whole direct-current high-speed circuit breaker structure. BRIEF DESCRIPTION OF THE DRAWINGS It is a front sectional view of the DC high-speed circuit breaker in Embodiment 1 of this invention, (a) shows the state at the time of electricity supply, (b) is a front sectional view which shows the state at the time of interruption | blocking. (A) is a perspective view which shows the replacement | exchange method of the replacement components (shielding side plate) of the direct-current high-speed circuit breaker in Embodiment 1 of this invention, (b) is an enlarged front view which shows a through-hole shape. It is a perspective view which shows only the exchangeable shielding side plate in Embodiment 1 of this invention. It is the perspective view which showed the inner side of the arc extinguishing chamber in Embodiment 1, 2 of this invention. BRIEF DESCRIPTION OF THE DRAWINGS In DC high-speed circuit breaker in Embodiment 1 of this invention, it is explanatory drawing which showed the state at the time of shielding side plate insertion, (a) is the perspective view which showed the whole DC high-speed circuit breaker, (b) is a figure ( FIG. 7A is a perspective view showing a state where a shielding metal fitting for a shielding side plate is attached at a portion C in FIG. 5A, and FIG. 5C is a perspective view showing the retaining metal fitting alone. It is a side view of Fig.6 (a). FIG. 7 is a front view of FIG. It is sectional drawing which looked at the IX-IX line of FIG. 7 in the arrow direction. It is sectional drawing which looked at the XX line of FIG. 7 in the arrow direction. It is sectional drawing which looked at the XI-XI line of FIG. 8 in the arrow direction. It is a perspective view which shows the replacement | exchange method of the shielding side plate of the DC high-speed circuit breaker in Embodiment 2 of this invention. It is a perspective view which shows only the exchangeable shielding side board in Embodiment 2 of this invention. It is the perspective view which showed the state at the time of insertion of the shielding side board in Embodiment 2 of this invention. It is a front view which shows the replacement | exchange state of the replacement parts in the conventional DC high-speed circuit breaker (patent document 1). It is a side view which shows the state which rotated the arc-extinguishing chamber at the time of cleaning of the DC high-speed circuit breaker which is another conventional example.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In addition, the same code | symbol shows the same or an equivalent part between each figure.

Embodiment 1 FIG.
The DC high-speed circuit breaker according to the first embodiment is provided with an insertion hole (through hole) in the lateral direction of the arc extinguishing chamber, and the shield side plate that is a replacement part can be inserted into and removed from the insertion hole. Only the part damaged or soiled by the arc can be easily inserted / removed (inserted / removed), and the contaminated part can be easily cleaned. When damaged, only the damaged part is replaced.

Hereinafter, based on FIGS. 1-11, the DC high-speed circuit breaker which is Embodiment 1 of this invention is demonstrated.
The DC high speed circuit breaker drives the arc extinguishing chamber 1, the upper conductor 2, the lower conductor 3, the contact arm 4, the fixed contact 5, the movable contact 6, the rotating shaft 7, and the movable contact 6 as shown in FIGS. The contact arm 4, the fixed-side arc runner 10, the movable-side arc runner 11, the grid portion 12, the release spring 13, the closing device 14, the latch 15, and the opening device 16 are configured.

When the circuit breaker is energized, the fixed contact 5 and the movable contact 6 are brought into contact with each other by the contact arm 4 and the upper conductor 2 and the lower conductor disposed in the lower part of the arc extinguishing chamber 1 as shown in FIG. A current flows through 3 through the contact arm 4.
At the time of interruption, as shown in FIG. 2B, the contact arm 4 rotates about the rotation shaft 7 with the lower conductor 3, so that the fixed contact 5 and the movable contact 6 are separated, and the fixed contact 5 and the movable contact are separated. An arc 8 is generated between the six. The generated arc 8 travels in the direction of arrow 9 in FIG. 2 and is commutated to a fixed-side arc runner 10 and a movable-side arc runner 11 arranged above the contact point, and the fixed-side arc runner 10 and the movable-side arc runner. 11 Run on.

  The arc 8 travels in the direction of the arrow 9 and is interrupted by the grid portion 12 above the arc extinguishing chamber. If the DC high-speed circuit breaker increases the number of interruptions, the arc-extinguishing chamber side plate will be damaged and soiled. Therefore, since cleaning at the time of maintenance and replacement of parts are necessary, the DC high-speed circuit breaker according to the first embodiment is configured as follows.

As shown in FIGS. 3 to 11, the DC high-speed circuit breaker according to the first embodiment includes a pair of shielding side plates 17 that prevent the arc generated in the arc extinguishing chamber during the interruption operation from blowing out to both sides. This shielding side plate 17 is equipped so that it can be inserted into and removed from the arc extinguishing chamber 1 through a through hole 1A provided in the outer wall.
The shielding side plate 17 is provided with an engaging projection 17a at the outer end thereof and a strip-like projection 17b at the longitudinal side thereof for positioning the shielding side plate 17.

When the shielding side plate 17 is inserted into the arc-extinguishing chamber 1 from the through hole 1A (when inserted in the direction of the arrow A), the engagement protrusion 17a of the shielding side plate 17 has a hole edge 1AA (FIG. 3). ) To prevent over-insertion (over-entry) of the shielding side plate 17, and the belt-like protrusion 17 b is a long groove 1 </ b> B provided in the arc extinguishing chamber 1 when the shielding side plate 17 is put in and out. Are fitted together to guide the taking-in / out operation of the shielding side plate 17 and to restrict the vertical movement, that is, to have the function of fixing the shielding side plate 17.
Note that the space between the lower longitudinal edges of the shielding side plates 17 has a blow-through space structure, and each shielding side plate 17 is inserted into the arc extinguishing chamber 1 as shown in FIG. The retaining bracket 170 is secured to the outer wall of the arc extinguishing chamber 1 by fixing bolts 171.

  In this way, the shielding side plate 17 is replaceably disposed on the side wall (arc extinguishing chamber component) portion (the portion 20 damaged or soiled by the arc) of the arc generation point that occurs during the interruption operation, and is shielded by the arc 8. When the side plate 17 is damaged or soiled, only the shielding side plate 17 is replaceable.

Embodiment 2. FIG.
Next, based on FIGS. 12-14, the DC high-speed circuit breaker which is Embodiment 2 of this invention is demonstrated.
In the second embodiment, an engagement protrusion 18a corresponding to the engagement protrusion 17a of the first embodiment is formed on the outer extension of the belt-like protrusion 18b, and the shielding side plate 18 is inserted into the arc extinguishing chamber 1. At this time (in the direction of arrow B), the engaging protrusion 18a is locked (contacted) by the hole edge 1AA of the through hole to prevent the shielding side plate 18 from entering too much. Further, the vertical protrusion of the shielding side plate 18 is prevented by the band-shaped protrusion 18b, like the band-shaped protrusion 17b of the first embodiment.
In the second embodiment as well, the shielding side plate 18 is prevented from coming off by a retaining metal fitting (not shown) corresponding to the retaining metal fitting 170 of the first embodiment.

  In the present invention, each embodiment can be appropriately modified or omitted within the scope of the invention.

1: arc extinguishing chamber, 1A: through hole, 1B: long groove,
2: upper conductor, 3: lower conductor, 4: contact arm,
5: fixed contact, 6: movable contact, 7: rotating shaft,
8: Arc, 10: Fixed side arc runner,
11: Movable side arc runner, 12: Grid part, 13: Opening spring,
14: closing device, 15: latch, 16: opening device,
17: shielding side plate, 17a: engagement protrusion, 17b: belt-like protrusion,
18: shielding side plate, 18a: engagement protrusion, 18b: belt-like protrusion,
19: Mounting bolt, 170: Retaining bracket, 171: Fixing bolt,
171a: fixing bolt through hole, 20: part damaged or soiled by arc.

Claims (3)

  Equipped with a through-hole provided in the outer wall of the arc-extinguishing chamber so that it can be freely put into and out of the arc-extinguishing chamber, and equipped with a pair of shielding side plates that prevent the arc generated during the interruption operation from blowing out to both sides, making the shielding side plates exchangeable A circuit breaker characterized by that.   On the long side surface of the shielding side plate, when the shielding side plate is put in and out, a belt-like projection that guides the putting in and out operation by fitting with a long groove provided in the arc extinguishing chamber and restricts the vertical movement is provided. The outer end of the side plate is provided with an engagement protrusion that prevents over-insertion by being locked by a hole edge of the through hole when the shielding side plate is inserted. Circuit breaker.   On the long side surface of the shielding side plate, when the shielding side plate is put in and out, a band-like protrusion that guides the loading and unloading operation by fitting with a long groove provided in the arc extinguishing chamber and regulates the vertical movement is provided. 2. The projecting part according to claim 1, further comprising an engaging projecting part that prevents over-insertion by being locked by a hole edge of the through-hole when the shielding side plate is inserted. Circuit breaker.