JPS622419B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an arc-extinguishing type circuit breaker that is disposed in a sealed arc-extinguishing chamber and uses a gaseous arc-extinguishing medium. A corresponding contact piece for cooperating with the hollow contact piece and a differential piston surrounding the hollow contact piece are arranged, the arc extinguishing medium being extinguished by the piston part with the smaller piston end face of the differential piston during the disconnection operation. is discharged from the compression chamber into the expansion chamber, and the piston portion of the differential piston having the larger piston end face within the expansion chamber is loaded by this arc-extinguishing medium.

It is known to blow out arcs in electrical circuit breakers, especially by means of a gas stream. In this case, the blast stream consisting of arc-quenching medium is, for example,
519238, it is produced by the actuation of a piston cooperating with an arc-quenching medium compression chamber, which piston is driven by an external drive. Such circuit breakers require an external drive with a correspondingly large driving force as the current to be interrupted becomes large.

Furthermore, in the oil type circuit breaker known from German Patent No. 524904, the pressure generated during the breaking operation is used to form an oil flow towards the arc for extinguishing the arc.
For this purpose, the arcing chamber contains a discharge device formed by a cylinder arranged in the arcing chamber, in which the differential piston moving has the smaller cross section of the piston. 1 located concentrically with respect to each contact piece.
It is adapted to discharge through an annular aperture or a plurality of apertures located concentrically with respect to each contact piece. In this case, the differential piston is driven with a predominant pressure occurring on the piston surface with its larger cross section, so that the above-mentioned delivery action and, by extension, the gas A strong cooling effect is produced in several places, which would only occur indoors. This circuit breaker also requires a spring to guide the differential piston back to its starting position.

Furthermore, according to German Patent No. 1130028, an arc-extinguishing circuit breaker is known which has a sealed casing and uses a gaseous arc-extinguishing medium, in which a plurality of holes are formed near the axis. A pumping member, which is designed as a piston and is intended to discharge the arc-extinguishing gas, is adapted to push the arc-extinguishing gas from the pressure-forming chamber into the arc chamber during the shutoff operation. Furthermore, this known circuit breaker has an actuating member for sliding the movable breaking piece and the piston, a corresponding actuating member and a nozzle-shaped nozzle arranged between the two chambers for centrally cooling the generated arc. The pumping member, which is formed as a differential pressure member and is to hold this nozzle, has a surface which is larger than the surface from which the arc-quenching medium is to be discharged and which is loaded by the arc pressure. arranged in such a way that the movable blocking piece entrains the pumping member through a stop of the dead connection;
and each connecting end of the movable shut-off piece is located between the nozzle and the pressure-forming chamber in all possible positions of the pumping member, which is designed as a known differential piston with a large surface difference, and said connecting end. I'm starting to do that. In the case of relatively large gas flows, the generated arc thus creates a pressure increase which acts on the larger upper side of the differential piston. As a result, the differential piston assists in the closing movement of the drive, which forces the smaller underside of the piston into the cylinder or pressure-forming chamber. Such circuit breakers have a relatively complex structure. A dead connection is also required, and the gas must be compressed in its own pressure-forming chamber and directed or forced through each opening in the piston into the vicinity of the arc between each blocking piece. It won't happen. Furthermore, this arc pressure can act on the larger upper side of the differential piston only after the nozzle-like element has been withdrawn from the following substantially stationary blocking piece.

Furthermore, in the electrical circuit breaker known from German Patent No. 664 985, a fluid arc-extinguishing medium is discharged by a piston towards the arc, so that the piston displaces the movable contact piece. Under the action of a spring that is tightened on account of the closing movement, the arc-extinguishing medium is moved from one chamber of the arc-extinguishing medium chamber by the first piston surface to the position-fixed contact formed in the hollow space. a second piston surface having an effective cross section equal to or larger than the first piston surface. It is partially limited by. This circuit breaker therefore requires a preloaded spring to drive the piston when the circuit breaker opens, and this spring must also be effective against the spring to return the piston. Two springs are therefore required. Furthermore, the pressure must be transmitted to the piston surface with the larger cross section not only via the hollow fixed contact piece, but also via the window section.

The object of the invention is to improve an arc-extinguishing circuit breaker of the type mentioned at the outset, simplifying its drive mechanism and improving the effect of blowing on the arc.

The above problem can be solved according to the present invention by providing an arc-extinguishing type circuit breaker (a) having a gaseous arc-extinguishing medium in a closed arc-extinguishing chamber, and (b) having a hollow contact piece in the arc-extinguishing chamber. (c) having a corresponding contact piece located within the arcing chamber and cooperating with the hollow contact piece; and (d) a differential located within the arcing chamber and guided along the hollow contact piece. (e) a differential piston with a smaller piston end face, having a piston and (e) discharging the arc-extinguishing medium from the compression chamber through the nozzle-like opening of the hollow contact piece into the expansion chamber during the breaking operation of the circuit breaker; (f) having a movable piston part, and (f) having a larger piston end face of the differential piston, the differential piston part located in the expansion chamber is loaded with an arc extinguishing medium discharged into the expansion chamber; (g) the hollow contact piece is surrounded by an insulating nozzle located coaxially and spaced therewith and delimiting the outside of the compression chamber; (h) the nozzle opening of the insulating nozzle; has a corresponding contact piece passing through it in the breaker-connected state, and (i) the differential piston part with the smaller piston end face is located in the compression chamber part between the hollow contact piece and the insulating nozzle; (j) The corresponding contact piece is fixedly connected to the differential piston.

The effect achieved by the present invention is particularly significant in the case of circuit breakers that use an arc-extinguishing medium heated by the interrupting arc, that is, a gaseous arc-extinguishing medium, in which the hot gas is removed from the arc-extinguishing medium compression chamber. It can be guided directly into the arc-extinguishing medium expansion chamber over the shortest distance, thereby creating a pressure increase P _K that exceeds the initial pressure P _Q of the arc-extinguishing medium in the arc-extinguishing circuit breaker.

The purpose in this case is to control the driving device without losing almost all of the thermal energy that is generated extremely quickly as a pressure increase P _K on the low-pressure side of the arc-extinguishing medium flow or the sprayed flow of the breaking arc that has been blown with the arc-extinguishing medium. It is to be used for work. In this case, a differential piston known per se is used, the smaller piston end face facing the high pressure side, ie the arc quenching medium compression chamber, and the larger piston end face facing the low pressure side, ie the arc quenching medium expansion chamber. It is advantageous to direct the already occurring relatively small pressure increase P _K into a much higher pressure P _O +P _H in the arc-quenching medium compression chamber. For this purpose, it can be advantageously used in a simple manner with reinforcement by a differential piston, in which case the above symbol P _H indicates the pressure increase due to compression in the arc-quenching medium compression chamber.

Furthermore, according to the invention, there is no need to divide the arc-extinguishing medium compression chamber, since a configuration similar to this is formed by a shut-off piece, a differential piston and an insulating nozzle in the connected state of the arc-extinguishing circuit breaker. This advantageously eliminates the need for energy-consuming or drive-energy-consuming springs for compressing the arc-extinguishing medium.

A further advantage is that the volume-variably closed arc extinguishing medium expansion chamber is connected to the arc extinguishing chamber in a simple manner by means of an arc extinguishing medium pressure balance hole at the end of the shutoff operation or at the end of the blowing movement; As a result, backflow of the arc-extinguishing medium through the nozzle blocking piece is avoided.
Moreover, this also ensures that no high-temperature gas can reach the arc-extinguishing section.

The invention will now be explained with reference to the illustrated embodiments.

FIG. 1 shows the main components of the invention, in which almost all parts are shown in cross-section. The differential piston part 1a of the piston manufactured as the differential piston 1 with the smaller piston end face 1c is guided in an arc-extinguishing medium in a tight manner between the arc-side part 5a of the nozzle blocking piece 5 and the insulating nozzle 9. In this case, the nozzle blocking piece 5
is the fixed part 1 at the arc side part 5a.
0, it is attached to the arc side end 9b of the insulating nozzle 9. The other end 9c of the insulating nozzle 9 is coupled to the restrictor 6a of the arc-extinguishing medium expansion chamber 6. The differential piston part 1b with the larger piston end face 1d is connected to the open part 5c of the nozzle blocking piece 5 and the inner limiter 6b of the arc-extinguishing medium expansion chamber 6.
The arc-extinguishing medium is likewise closely guided between the parts 1, 5, 9 and 6a, and the differential piston 1 as a whole is movable in the direction of the common central axis of the parts 1, 5, 9 and 6a. It is located.

If, on the other hand, the differential piston 1 is stationary, the above-mentioned parts 5, 10, 9 connected to one another
and 6a, of course, in the direction of said common central axis along the differential piston 1 which serves as a guide;
They can exercise together.

In a system consisting of parts 5, 10, 9 and 6a and stationary with respect to the surroundings, during switching off the differential piston 1 is moved in a known manner by a drive, not shown, e.g. It is moved in the direction of arrow k by means of a spring drive. Independently or in conjunction with this movement of the differential piston 1,
At approximately the same time, the blocking piece 3 is also moved in the direction of the arrow s in a known manner by means of a device which is also not shown. In this case, directions k and s are the same direction.

Due to the differential piston 1 moving in the direction indicated by the symbol K, the arc extinguishing medium at the initial pressure P _O in the arc extinguishing medium compression chamber 2 is compressed to a high pressure P _O +P _H. The arc-extinguishing medium at pressure P ₀ is forced by the differential piston part 1b through the arc-extinguishing medium pressure balance hole 7 into the outer part 8 of the restriction body 6a of the arc-extinguishing medium expansion chamber 6, also at an initial pressure P ₀ . The blocking piece 3 that moves in the direction of arrow S or K is the nozzle blocking piece 5.
As soon as they are released from the engaged state, an interrupting arc is generated between the interrupting pieces 3 and 5, and at the same time, arc-extinguishing medium compressed to a high pressure flows from the arc-extinguishing medium compression chamber 2 into the interrupting arc as an arc-extinguishing medium flow. flowing towards. In this case, the thermal energy blown away by the interrupting arc is transferred to the low-pressure side of the arc-extinguishing medium stream or the blasting stream, i.e. to the hollow chamber 5d in the nozzle blocking piece 5 or the arc-extinguishing medium expansion chamber, which serves as an arc-extinguishing medium passage. 6 causes a pressure increase P _K that exceeds the initial pressure of the arc-quenching medium present therein, resulting in an arc-quenching medium expansion chamber 6
An increased pressure P _O +P _K arises within.

By the way, when the systems 5, 10, 9 and 6a are stationary, the differential piston 1 exerts a force F _z due to the force obtained as the product of the area of the large piston end face 1d and the increased pressure P _O +P _K =A _1d・(P _O +P
_K ) is additionally pushed in the direction of K, and thereby the differential piston 1 is additionally driven by the converted thermal energy of the interrupting arc, or the aforementioned non-illustrated portion of the differential piston 1 The action of the drive is correspondingly strengthened or relieved.

To give an example of the pressure state during shutoff operation,
The pressure rise P _H due to the differential piston 1 in the arc-quenching medium compression chamber 2 is P _H =8-10 bar, whereas the pressure rise P _K in the arc-quenching medium expansion chamber 6 is P _K = It is 4 bar.

Now, the area of the smaller piston end face 1c on the arc-extinguishing medium compression chamber side is A _1c , and this area is relative to the area A _1d of the larger piston end face 1d on the arc-extinguishing medium expansion chamber side, A _1c :A _1d = If a differential piston 1 with a ratio of 1:2 is used, an enhanced action of the thermal energy of the interrupting arc is facilitated in the generation of the arc-extinguishing medium flow or the blowing flow and in the actuation of the movable circuit breaker parts. recognized.

The high pressure P _O + P _H based on the compression in the arc-extinguishing medium compression chamber 2 and mentioned in the introduction to the solution of the problem is
The arc-extinguishing medium expansion chamber 6 is always larger than the initially mentioned increased pressure P _O +P _K caused by heating of the arc-extinguishing medium.

With regard to the certain pressure increase in the arc-extinguishing medium expansion chamber 6 relative to the arc-extinguishing medium compression chamber 2 during connection of the arc-extinguishing circuit breaker, the alternative embodiment of FIG. 2 will be described.

At the end of the arc-extinguishing medium flow or blowing period, the arc-extinguishing medium pressure balance hole 7 is finally opened by the differential piston part 1b for the heated arc-extinguishing medium and thereby the pressure increase P _K is the initial pressure P _O
to the outside 8 of the arc extinguisher, so that no hot arc extinguishing medium or gas is returned into the arc extinguishing zone.

By the way, if the differential piston 1 is stationary, the system of parts 5, 10, 9 and 6a, hitherto considered stationary, can be replaced by a drive device (not shown) of the known type. is caused to move in the direction of arrow L.

Since the differential piston 1 is now stationary, in this case the pressure increased in the arc-extinguishing medium expansion chamber 6 is P _O +P _K
However, this time the flange 6 of the restricting body 6a of the arc-extinguishing medium expansion chamber 6 is made in the shape of a disk, for example, in the same manner as when the differential piston 1 was made movable.
For e, the limiter 6a or the entire system 5, 10,
9 and 6a act when they move in the direction of arrow L. However, this increases the pressure P _O +
The already mentioned effect of P _K remains unchanged.

FIG. 2 shows an alternative embodiment to the embodiment shown in FIG. In this case, parts that are the same as those in FIG. 1 are given the same reference numerals as those in FIG.

In order to prevent a low pressure from forming in the arc-extinguishing medium expansion chamber 6 relative to its exterior or the arc-extinguishing chamber 8 during a slight current interruption, the arc-extinguishing medium expansion chamber 6 and its outer surroundings or arc-extinguishing chamber 6 are connected to each other. At least 1 between chamber 8
Two check valves 12 are provided. When low pressure occurs in the arc extinguishing medium expansion chamber 6, the check valve 12 opens, and the arc extinguishing medium expansion chamber 6 until pressure equilibrium is achieved.

As shown in FIG. 2, the hole of the check valve 12 passes through the annular flange 1f of the differential piston 1.

Furthermore, a further check valve 13 is arranged between the arc-extinguishing medium expansion chamber 6 and the arc-extinguishing medium compression chamber 2, so that during the connection, the arc-extinguishing medium compression chamber 2 is disposed within the arc-extinguishing medium expansion chamber 6. No pressure increase occurs.
A certain increase in pressure is therefore applied to the arc-quenching medium compression chamber 2 via a passage 13a provided in the differential piston 1 and a check valve 13 which opens upon pressure increase.
in this case the passage 13a is the differential piston 1
It passes through the tube 1e and the annular flange 1f.

FIG. 3a is a schematic cross-sectional view of an arc-extinguishing circuit breaker according to the invention with a stationary differential piston in the connected state; In this case, parts in FIG. 3a that are the same as those in FIGS. 1 and 2 are given the same reference numerals as in FIGS. 1 and 2.

The immovable differential piston 1 is immovably arranged on the arc extinguishing chamber cover 8a on the drive device side by a fixed rod 1g, and the blocking piece 3 is connected to the arc extinguishing chamber cover 8b on one side of the blocking side, in which case both cover 8
An insulating cylinder 8c is arranged between a and 8b.

The drive of the arc-extinguishing circuit breaker is symbolized by an insulating rod 14, which during the interrupting operation, when the arc-extinguishing chamber is stationary, is indicated by the arrow L.
, so that parts 5, 10, 9 and 6a of the arc-extinguishing circuit breaker are also moved in the same direction.

In the shut-off state, as shown in FIG. 3a, the arc-extinguishing medium compression chamber 2 is closed by a permanently arranged shut-off piece 3, and by a similarly fixedly arranged shut-off piece 3. The movable piston 1 opens the arc extinguishing medium compression chamber 2 to have the maximum chamber volume. The adjacent chamber 6f still has the maximum volume,
and the arc extinguishing chamber 8 via the arc extinguishing medium pressure balance hole 7
is connected to. The arc extinguishing medium expansion chamber 6 has a minimum volume together with the hollow chamber 5d of the nozzle blocking piece 5, and this volume chamber is closed to the arc extinguishing chamber 8, the adjacent chamber 6f and the arc extinguishing medium compression chamber 2. In this case there is an initial pressure P _O in chambers 2, 5d, 6, 6f and 8.

FIG. 3b shows the arc-extinguishing type circuit breaker of FIG. 3a in a state where the arc 4 is being emitted during the above-mentioned breaking operation. The parts in FIG. 3b are the same as the parts in FIG. 3a and are therefore given the same reference numerals.

In this shutoff operating state, the system consisting of parts 5, 10, 9 and 6a is moved in direction L towards the arcing chamber cover 8a on the drive side by means of an insulating rod 14, which symbolizes the drive. . Due to this movement relative to the stationary parts 1 and 3, the volume of the arc-extinguishing medium compression chamber 2 is significantly reduced, whereby the arc-extinguishing medium is compressed and in this case the blocking piece 3
is released towards the interrupting arc 4 as an arc-extinguishing medium flow. During this time, the arc-extinguishing medium portion heated by the interrupting arc 4 flows into the arc-extinguishing medium expansion chamber 6 through the hollow chamber 5d of the nozzle blocking piece 5, and the arc-extinguishing medium portion is heated by the arc-extinguishing medium expansion chamber 6. The arc-extinguishing medium expansion chamber 6 is closed by moving the arc extinguishing medium expansion chamber 6a in cooperation with the drive device 14 in the direction of the arrow L to the position shown.
is increasing. The generation of a high pressure (P _O +P _H ) in the arc-quenching medium compression chamber 2 as well as an increasing pressure (P _O +P _K ) in the arc-quenching medium expansion chamber 6 is then interrupted in the respective cutoff. This can be achieved by the current, the drive of the circuit breaker, etc. and by a corresponding suitable switch construction.

FIG. 3c shows the circuit breaker of FIGS. 3a and 3b in the disconnected state, with the same reference numerals as in FIG. 3b.

The parts 5, 10, 9 and 6a are moved by the drive device 14 in the direction of the arrow L in cooperation with the arc extinguishing medium heated by the switch arc 4.
has reached the tripped position of the circuit breaker.
The arc has been extinguished, and the arc-extinguishing medium compression chamber 2, which has a minimum chamber volume, opens into the arc-extinguishing chamber 8 via the insulating nozzle 9, and a pressure equilibrium has thereby occurred. The arc-quenching medium expansion chamber 6 has reached its maximum volume and is also connected to the arc-quenching chamber 8 via the now open arc-quenching medium pressure balance hole 7, so that a pressure equilibrium occurs. .

FIG. 4a is a schematic cross-sectional view of the arc-extinguishing circuit breaker of the present invention having a movable differential piston 1 in a connected state, and in this case, the same parts as in FIG. The same symbols are attached.

Part 3a, consisting of parts 5, 10, 9 and 6a.
In the embodiment shown in FIGS. 4a to 3c, the movable system is fixed to the arc extinguishing chamber cover 8a on the drive device side by means of a fixed part 6g in the embodiment shown in FIGS. 4a to 4c. It is arranged immovably together with the arc chamber 8.

According to this embodiment of the invention, the movable blocking piece 3
is mechanically connected to the differential piston 1 by an insulating part 11.

The insulating rod 14, which symbolizes the drive in a manner known per se, is a movable differential piston 1.
installed on. When interrupting the arc-extinguishing circuit breaker,
The system of parts 1, 11 and 3 moves in the direction of the arrow K, in which case the same operating process as described with respect to FIGS. 3a to 3c takes place again.

FIG. 4b, on the other hand, shows the arc-extinguishing type circuit breaker of FIG. 4a in the above-mentioned breaking operation state in which an arc 4 is generated, as in FIG. 3b.

FIG. 4c shows the circuit breaker in the disconnected state, in which case parts that are the same as in FIG. 4a are provided with the same reference numerals as in FIG. 4a.

According to an advantageous embodiment of the exemplary embodiment shown in FIGS. 1 to 4c, the tubular nozzle blocking piece 5 is coaxially surrounded with a spacing by a tubular insulating nozzle 9, in which case the insulating nozzle 9 is a limiter 6a of the arc-extinguishing medium expansion chamber 6, which is arranged coaxially with respect to the nozzle blocking piece 5 via an annular intermediate flange 6c.
The inner diameter of the nozzle blocking piece 5 is smaller than the inner diameter of the surrounding wall part 6d, and the tubular surrounding wall part 6d is connected to the free side part 5c of the nozzle blocking piece 5. It is closed by a circular branch-shaped flange 6e. The tubular peripheral wall part 6d in this case has arc-extinguishing medium pressure balance holes 7 at its end on the side of the intermediate flange 6c, these
In the breaking operation state of the arc-extinguishing type circuit breaker, the differential piston portion 1b having the larger piston end face 1d is opened.

The differential piston 1 is in this case formed by a tube 1e, whose differential piston part 1b with its larger piston end face 1d is connected to a tubular flange 1b.
It has the same inner diameter as the tube 1e, but a larger outer diameter.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a schematic sectional view of the main components of the device of the present invention, and FIG. 2 is a schematic sectional view corresponding to FIG. 1 with a valve added. , 3a-3b are schematic cross-sectional views of another embodiment of the invention with a stationary differential piston,
In this case, FIG. 3a is a diagram showing a connected state, FIG. 3b is a diagram showing a state in which an arc is being generated and the interrupting operation is in progress, and FIG. 3c is a diagram showing a disconnected state.
4a to 4c are schematic sectional views of a further embodiment with a movable differential piston, in which case FIG. 4a shows the connected state and FIG. 4b shows the state in the shutoff operation. FIG. 4C is a diagram showing a blocked state. 1... Differential piston, 1a... Differential piston part, 1b... Differential piston part, 1c... Smaller piston end face, 1d... Larger piston end face, 1e... Differential piston tube, 1f... annular flange, 1g... fixed rod, 2... arc extinguishing medium compression chamber, 3... blocking piece, 4... arc, 5... nozzle blocking piece, 5a... arc generation side of nozzle blocking piece Portion, 5b... Outer wall portion of nozzle blocking piece, 5
c...Cantilevered extension part of nozzle blocking piece, 5d...
Hollow chamber, 6... arc extinguishing medium expansion chamber, 6a... limiter, 6b... inner limiter, 6c... intermediate flange, 6d... peripheral wall portion, 6e... flange, 6f
... Adjacent chamber, 6g... Fixed part, 7... Arc-extinguishing medium pressure balance hole, 8... Arc-extinguishing chamber, 8a... Arc-extinguishing chamber cover, 8b... Arc-extinguishing chamber cover, 8c... Insulating cylinder, 9... Insulated nozzle, 9a... Inner wall of the insulated nozzle, 9b... End of the insulated nozzle on the arc generation side, 9c... End of the insulated nozzle on the opposite side from the arc generation side, 10... Fixed part, 11...Insulating part, 12...Check valve, 13...Check valve, 13
a... Passage, 14... Insulating rod.

Claims (1)

[Claims] 1. An arc-extinguishing type circuit breaker, which (a) has a gaseous arc-extinguishing medium in a closed arc-extinguishing chamber, (b) has a hollow contact piece in the arc-extinguishing chamber, (c) having a corresponding contact piece located within the arcing chamber and cooperating with the hollow contact piece, and (d) having a differential piston located within the arcing chamber and guided along the hollow contact piece. (e) a differential piston portion with a smaller piston end surface for discharging arc-extinguishing medium from the compression chamber through a nozzle-like opening in the hollow contact piece into the expansion chamber during the breaking operation of the circuit breaker; (f) In a type of differential piston having a larger piston end face and having an arc-extinguishing medium discharged into the expansion chamber, the portion of the differential piston located within the expansion chamber is loaded with the arc-extinguishing medium, (g) a hollow contact piece is surrounded by an insulating nozzle located coaxially and spaced apart therefrom and delimiting the outside of the compression chamber; (h) a nozzle opening of the insulating nozzle is surrounded by an insulating nozzle; In the connected state, the corresponding contact piece passes through and (i) the differential piston part with the smaller piston end face is movable in the compression chamber part between the hollow contact piece and the insulating nozzle; (j) An arc-extinguishing circuit breaker characterized by the matters described in (a) to (j) above, wherein the corresponding contact piece is immovably connected to the differential piston. 2 The differential piston 1 and the corresponding contact piece 3 are in the arc extinguishing chamber 8
a, 8b, 8c, the hollow contact piece 5, the insulating nozzle 9, and each limiter 6 of the expansion chamber 6.
The arc-extinguishing type circuit breaker according to claim 1, wherein the arc-extinguishing circuit breaker is connected to a drive device. 3. The hollow contact piece 5, the insulating nozzle 9 and each limiter 6a, 6b, 6c, 6d of the expansion chamber 6 are immovably connected to each other, and the differential piston 1 and the corresponding contact piece 3 are connected to the drive device. The arc-extinguishing type circuit breaker according to claim 1, wherein the arc-extinguishing circuit breaker is connected. 4 Larger piston end face 1 of differential piston 1
At least one first check valve 12 connecting the expansion chamber 6 and the arc extinguishing chamber 8 is arranged at d, and this check valve 12 responds to the formation of negative pressure in the expansion chamber 6. The arc-extinguishing type circuit breaker according to any one of claims 1 to 3. 5 Smaller piston end face 1 of differential piston 1
At least one second check valve 13 connecting the compression chamber 2 and the expansion chamber 6 is arranged at c, which check valve 13 prevents the formation of an overpressure in the expansion chamber 6 when the connection is activated. be forced to respond to
The arc-extinguishing type circuit breaker according to claim 4.