JPH10208593A - Gas switch - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To surely extinguish an arc even in a condition where it is difficult to extinguish the arc. A movable contact (2) provided to penetrate a fixed contact (12) of a fixed portion (1) when a gas switch is "closed" is provided at an end of the fixed portion (1) side. By providing a pressure relief valve 25 that opens when the gas pressure in the arc-extinguishing chamber 17 exceeds a predetermined value in the axial-extinguishing hole 22 of the arc-extinguishing hole 21 including the radial-direction arc extinguishing hole 23, The opening to the outside of the radial direction arc extinguishing hole 23 is the fixing portion 1
Even if the movable contact 2 moves to a position communicating with the external space, the pressure-releasing valve 25 operates as long as the gas pressure in the arc-extinguishing chamber 17 as the inner space of the fixed part 1 including the insulating nozzle 14 does not exceed a predetermined value. Since the gas does not escape to the external space through the arc extinguishing hole 21 due to being kept closed, the pressure release valve 25 is opened only when a predetermined gas pressure is reached, and a gas flow is generated to cool and extinguish the arc. The action works more reliably.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a breaking performance of a circuit breaker such as a disconnector or a grounding switch used in a gas insulated switchgear filled with SF ₆ gas as an insulating gas as compared with a circuit breaker. And a gas switch requiring the same.

[0002]

2. Description of the Related Art Unlike a circuit breaker, a gas switch requires a breaking capacity of, for example, several thousand volts and several hundred amperes. FIG. 11 is a cross-sectional view when the conventional gas switch is "closed", and mainly shows a fixing portion. In this figure, a fixed part 1 of a gas switch comprises a pedestal 11, a fixed contact 12 attached to the pedestal 11, and an insulating nozzle 14 provided outside the pedestal 11, each of which is coaxially arranged. However, the fixed contact 12 is made up of a number of small pieces having a cross section as shown in the figure and arranged in a ring shape so as to overlap in the circumferential direction, and these small pieces are bundled by the spring 121 to be integrated. This ring-shaped fixed contact 12
The movable contact 2 is inserted through the inner hole of
Each small piece of the fixed contact 12 is pressed against the movable contact 2 by the spring force of the spring 121, and the contact resistance between the fixed contact 12 and the movable contact 2 is kept at a small value. In this figure, the fixed contact 12 and the movable contact 2 are in a contact state, and are in a “closed” state as a switch.

[0003] The movable contact 2 is in the form of a round bar sharing the axial center of the fixed portion 1 arranged coaxially, and has an arc extinguishing hole 21 at its tip. The arc-extinguishing hole 21 includes an axial arc-extinguishing hole 22 provided so as to coincide with the center axis of the movable contact 2 and a radial-extinguishing hole 23 communicating with the opposite end of the arc-extinguishing hole 21. . The function of the arc extinguishing hole 21 will be described later.

The insulating nozzle 14 is made of an insulating material having excellent heat resistance and arc resistance, such as a fluororesin, as its name implies, and its inner space forms an arc extinguishing chamber 17. In this figure, the movable contact 2 occupies a large space of the arc-extinguishing chamber 17. The pedestal 11 has a concave portion 16 that forms a part of the arc-extinguishing chamber 17 in the upper part of the figure. The insulating nozzle 14 is provided with first and second protrusions 141 and 142 protruding toward the inner diameter side, and the first and second nozzle holes 143 and 144 formed in the respective protrusions 141 and 142 are provided. As described later, during the current interruption operation,
Fixed contact 12 and movable contact 2 that are mechanically separated from each other
And the arc that keeps the electrical short circuit extinguished,
The so-called arc extinguishing is provided so as to be performed more effectively. A concave portion 18 is formed between the projecting portions 141 and 142, and has an effect of ensuring a large volume of the arc-extinguishing chamber 17 like the concave portion 16.

[0005] FIG. 12 shows a state of “open” from the state of “closed” in FIG. 11.
FIG. 12 is a cross-sectional view of the gas switch immediately after the start of the current interruption operation, in which all the components of the gas switch are the same as in FIG. 11 only when the movable contact 2 moves. This figure shows a state immediately after the movable contact 2 has been driven in the direction of arrow 20 by a driving device (not shown) and mechanically separated from the fixed contact 12.
Arc contact 122 of movable contact 2 and arc contact 2 of movable contact 2
An arc 3 is generated between the first and second electrodes 4 and 4 and still electrically maintains the "closed" state. The arc contacts 122 and 24 are made of an arc-resistant metal, such as a copper-tungsten alloy, which hardly evaporates and is worn even by a high temperature of the arc. Fixed contacts 12 other than arc contacts 122 and 24
The movable contact 2 is made of copper having good conductivity.

When the arc 3 is generated, the surrounding space, that is, the gas in the arc extinguishing chamber 17 is heated, and the pressure in the arc extinguishing chamber 17 increases. The characteristic of this gas switch is that the arc is extinguished by utilizing the gas flow generated by the pressure increase. The gas flow is generated according to the pressure difference through the arc extinguishing hole 21 communicating the arc extinguishing chamber 17 and the outside. The arc extinguishing hole 21 is composed of an axial extinguishing hole 22 and a radial extinguishing hole 2
3 from the arc extinguishing chamber 17 to the axial arc extinguishing hole 22
And through the radial arc extinguishing hole 23 to communicate with the outside. In this figure, since the exit of the radial arc extinguishing hole 23 is closed by the second projection 142, the arc extinguishing chamber 17 and the external This is a stage where no gas flow is generated due to lack of communication with the space, and thus an arc extinguishing effect has not yet occurred. At this point, the arc 3 has not yet been generated and the length of the arc 3 is short, so that the gas pressure in the arc-extinguishing chamber 17 hardly increases.

FIG. 13 is a cross-sectional view of the gas switch showing a state immediately before arc extinction is established at a point further from FIG. The radial direction arc extinguishing hole 23 is located further down from the second nozzle hole 144 and is located in a wide space to communicate the arc extinguishing chamber 17 with this space. On the other hand, the arc 3 extends for a long time, so that the gas in the arc-extinguishing chamber 17 is heated to a higher pressure than in the case of FIG. 12, while the arc-extinguishing hole 21 is formed in the arc-extinguishing chamber 17. And the external space, a gas flow 4 indicated by an arrow in the figure is generated, and the arc 3 is formed in the axial direction arc extinguishing hole 2.
It is pulled into 2 to increase the length, and is cooled to extinguish to achieve arc extinction.

[0008]

The above-mentioned gas switch has the following problems. The length of the insulating nozzle 14 and the radial arc-extinguishing hole, which is a blow-out hole of the movable contact 2, so that gas is not blown out until the gas pressure in the arc-extinguishing chamber 17 increases to a pressure at which current can be sufficiently interrupted by the arc. The positional relationship with the exit 23 is set. The arc 3 is extinguished at a so-called zero point where the instantaneous value of the AC current becomes zero. On the other hand, the time when the cutoff command is issued and the cutoff operation is started has nothing to do with the phase of the AC current. Therefore, when the start time of the shutoff operation is close to the next zero point, it cannot be said that there is no case where the pressure at the moment when the blowout hole communicates with the outside of the arc-extinguishing chamber does not increase to a required value. The timing at which the gas is blown out can be controlled almost exclusively by the length of the insulating nozzle or by a blowout hole formed perpendicular to the axial direction of the movable contact. The contact surface of the fixed contact is made of copper instead of arc-resistant metal such as copper-tungsten alloy, which has excellent arc resistance in order to provide current-carrying performance. Disappears. Since the blowout of hot gas due to the pressure increase due to the arc blows only from the tip of the nozzle to the outside or from the hole at the tip of the movable contact to the outside,
The cooling and extinguishing effects are easy to obtain for the arc near the tip of the movable contact, but the arc cooling and extinguishing effects for the other parts of the arc are almost the same as those of the parallel arc extinguishing method. I can't get it. Although the pressure in the arc-extinguishing chamber 17 is increased by the arc at the time of current interruption, the arc energy is small for a few milliseconds after the opening and the negative pressure due to the movement of the movable contact does not generate a positive pressure that can be interrupted. Therefore, there is a period in which it is difficult to cut off a few ms after the opening, and the arc time tends to be long.

An object of the present invention is to solve such a problem and to provide a gas switch which can surely extinguish an arc even under conditions where it is difficult to extinguish the arc.

[0010]

According to the present invention, there is provided a container filled with an insulating gas.
A fixed part, a movable contact inserted into and contactable with the ring-shaped fixed contact of the fixed part, and an insulating nozzle provided to cover the fixed contact are provided, and an arc extinguishing chamber is provided inside the insulating nozzle. A side of the insulating nozzle into which the movable contact is inserted is narrowed to form a protruding portion having a nozzle hole that protrudes inward and into which the movable contact is inserted, and the movable contact has a side that is inserted into the fixed contact. An axial arc extinguishing hole provided at the tip end of the shaft object and a radial arc extinguishing hole communicating with the axial arc extinguishing hole and passing through the movable contact in the radial direction and opening to the outside of the movable contact. In a gas switch provided with an arc extinguishing hole, by providing a pressure relief valve in the arc extinguishing hole that closes the arc extinguishing hole and opens when the gas pressure in the arc extinguishing chamber exceeds a predetermined value, Even if the movable contact moves to the position where the opening to the outside of the radial direction arc extinguishing hole communicates with the external space of the fixed part, the pressure relief valve remains closed unless the gas pressure in the arc extinguishing chamber exceeds a predetermined value. As a result, the gas does not escape to the external space through the arc extinguishing hole, and only when a predetermined gas pressure is reached, the pressure relief valve is opened to generate a gas flow, and the arc extinguishing function works. The pressure relief valve may be provided in the axial arc extinguishing hole or in the radial arc extinguishing hole.

In the conventional gas switch described above, at least three protrusions and at least two recesses sandwiched between the protrusions are formed on the insulating nozzle, so that the opening of the radial arc extinguishing hole is formed as one recess. Then, a gas flow corresponding to the difference in gas pressure between the arc-extinguishing chamber and the concave portion is generated. When the breaking current is small, the arc can be extinguished by this gas flow to achieve arc extinction. Since a plurality of concave portions are provided, even if the arc is not extinguished in the first concave portion, the arc is extinguished by the gas flow to the next concave portion. Even when the arc current is large and the arc is not extinguished by the gas flow into the recess, the gas flowing into the recess does not flow out of the arc-extinguishing chamber including the recess, so that the radial arc extinguishing hole is located outside the insulating nozzle. The gas in the arc-extinguishing chamber which communicates with the space described above does not cause a decrease in gas pressure with respect to the gas flow flowing out to the external space.

In the above-mentioned conventional gas switch, an arc extinguishing hole closing rod made of an insulating material is attached to a fixed portion at a position to be inserted into the axial arc extinguishing hole of the movable contact.
By forming the length of the axial arc extinguishing hole until the movable contact separates from the fixed contact at the predetermined position during the breaking operation, the axial extinguishing hole is extended to the position where the arc extinguishing hole closing rod exits the axial arc extinguishing hole. Even if the opening of the radial arc extinguishing hole comes out of the insulating nozzle, no gas flow from the arc extinguishing chamber to the outside occurs, delaying the arc extinguishing action by the gas flow. Thus, it is possible to wait for the gas pressure in the arc extinguishing chamber to further increase.

In addition, a metal arc extinguishing rod is provided in place of the arc extinguishing hole closing rod, and this arc extinguishing rod is used when the fixed contact and the movable contact are mechanically separated from each other during the breaking operation. By forming the arc so as to escape from the arc hole, the arc starting point on the fixed portion side becomes the tip of the arc extinguishing hole closing bar, so that the wear of the fixed contact can be reduced. Also,
If an arc extinguishing cylinder is provided instead of the arc extinguishing rod, and the inner hole of this arc extinguishing cylinder communicates with the interior space of the arc extinguishing chamber and the external space, the inner hole of the arc extinguishing cylinder is raised due to the rise of gas in the arc extinguishing chamber. A gas flow passes through the arc, and the gas flow causes the arc to be sucked into the arc-extinguishing cylinder, thereby effecting cooling and arc-extinguishing action as in the case of the axial arc-extinguishing hole. If a pressure relief valve that closes the inner hole of the arc-extinguishing cylinder and becomes “open” when the gas pressure in the arc-extinguishing chamber exceeds a predetermined value is provided, it is the same as the above-described configuration in which the pressure relief valve is provided in the arc-extinguishing hole. In addition, it is possible to prevent gas flow from occurring until the gas pressure in the arc-extinguishing chamber exceeds a predetermined value.

In the conventional gas switch described above, the opening of the arc extinguishing hole in the radial direction is provided at a position where the movable contact communicates with the external space at a predetermined time delay from the time when the movable contact is mechanically separated from the fixed contact. However, at this time, the arc has not developed, so it does not contribute to the gas pressure increase in the arc-extinguishing chamber. Instead, the gas pressure in the arc-extinguishing chamber increases due to the increase in the volume of the arc-extinguishing chamber due to the movable contact coming out of the arc-extinguishing chamber. As a result, the gas flow flowing from the opening of the radial direction arc extinguishing hole toward the arc extinguishing chamber is generated, and the short-time arc generated by the gas flow can be extinguished. Also,
If the ratio of the volume of the movable contact in the arc-extinguishing chamber is increased while the gas switch is in the "closed" state, the ratio of volume increase when the movable contact comes out of the arc-extinguishing chamber after the shut-off operation starts is increased. As a result, the degree of gas pressure decrease becomes significant, and a larger gas flow is obtained. If the opening of the axial direction arc extinguishing hole into the arc extinguishing chamber is formed so as to expand toward the arc extinguishing chamber, a gas flow ejected from this opening has a radially expanding component, and the tip of the movable contact The effect of extinguishing the initial arc generated in the peripheral portion is enhanced.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments. FIG. 1 is a sectional view of a gas switch according to a first embodiment of the present invention immediately after a shut-off operation is started. The same components as those in FIG. And duplicate explanations are omitted. The difference between FIG. 1 and FIG. 12 is that a pressure relief valve 25 is provided in the axial arc extinguishing hole 22. The pressure relief valve 25 is commercially available, for example, composed of a metal ball for closing the hole and a spring for pressing the metal ball into the hole.

In the figure, since the outlet of the arc-extinguishing hole 23 of the arc-extinguishing hole 21 is closed by the second protrusion 142 of the insulating nozzle 14, the communication between the arc-extinguishing chamber 17 and the external space is established. However, even when the movable contact 2A further moves downward and the outlet of the radial direction arc extinguishing hole 23 communicates with the external space, the pressure difference between the arc extinguishing chamber 17 and the external space communicating with the arc extinguishing chamber 17 is maintained. When the pressure does not exceed the fixed value set for the pressure relief valve 25, the pressure relief valve 25 closes the axial arc extinguishing hole 22 and does not allow gas to pass therethrough. When the pressure difference exceeds a certain value, the pressure relief valve 25 is opened, and a gas flow 4 shown in FIG. 13 is generated from the arc extinguishing chamber 17 to the external space, and the arc extinguishing function described above works.

Since the gas flow 4 does not occur unless the pressure difference exceeds a certain value by providing the pressure relief valve 25, the gas flow occurs while the pressure difference is small, and as a result, the pressure in the arc-extinguishing chamber 17 rises. And the risk of arc extinguishing failure being eliminated. FIG. 2 is a sectional view of a gas switch immediately after the start of a shut-off operation according to a second embodiment of the present invention. The same components as those in FIG. And duplicate explanations are omitted. 2 is different from FIG. 1 in that a pressure relief valve 25B is provided in a radial direction arc extinguishing hole 23.
That is, the pressure relief valve 25B is provided in each of the left and right radial arc extinguishing holes 23 communicating with the axial arc extinguishing hole 22. In the case of the first embodiment described above, one pressure relief valve 25 may be used, but in the second embodiment, the two pressure relief valves 25B are required, and the first embodiment is more practical. However, the method for manufacturing the movable contact 2B and the arc-extinguishing hole 21 and the pressure relief valve 25
It is not always possible to conclude that the first embodiment is superior in terms of the mounting structure of B to these components and the method thereof, and any of these embodiments may be employed as appropriate. In FIG. 2, two pressure relief valves 25B are required because the outlets of the radial direction arc extinguishing holes 23 are provided on both sides.
If only one of them is used, the same as in the first embodiment,
Only one 5B is required.

FIG. 3 is a sectional view of a gas switch immediately after the start of a shut-off operation according to a third embodiment of the present invention. The same components as those in FIG. Is appended with a suffix C to eliminate redundant description. 3 and 11
3 is different from the insulating nozzle 14C of FIG. 3 in that the second protrusion 142 of the insulating nozzle 14 of FIG.
81, 182 and 183 are provided. These three recesses 181, 182, 183 are respectively provided with protrusions 141, 181.
1421, 1422, 1423, the outer diameter wall of the insulating nozzle 14C and the movable contact 2 form a closed space.

As shown in FIG. 3, when an arc 3 is generated between the fixed contact 12 and the movable contact 2, a gap is formed between the first protrusion 141 and the corner of the tip of the movable contact 2. At this point, if the gas pressure in the arc-extinguishing chamber 17 is increased, a gas flow (not shown) flowing from the arc-extinguishing chamber 17 to the concave portion 181 is generated. When the current of the arc 3 is small, the gas flow extinguishes the arc 3. be able to. Also, as shown in the figure, the radial arc extinguishing hole 23 is
When the gas pressure in the arc-extinguishing chamber 17 is rising, the arc-extinguishing hole 22
Then, a gas flow 40 flowing through the radial arc extinguishing hole 23 into the space of the concave portion 182 at normal pressure is generated. In the figure, the gas flow 40
It is apparent that the position of the actual arc 3 is unstable due to the electromagnetic force acting on its own current and the current flowing through the fixed contact 12 and the movable contact 2, and as shown in FIG. And movable contact 2
May not be at the shortest distance between the respective arc-resistant metals 122 and 24 but may have a shape that swells greatly in the arc-extinguishing chamber 17. Under the influence, a phenomenon occurs in which the air is sucked into the axial arc extinguishing hole 22 as shown in FIG.
Also in this case, there is a high possibility that the arc 3 will be extinguished before the movable contact 2 is driven downward as shown in FIG. In the same way, for example, the gas flow 4 to the concave portion 182
Even when the arc is not extinguished due to 0, there is a possibility that the arc 3 is extinguished and the arc extinguished by the gas flow flowing into the concavity 183 and the concave 183 communicating with the arc extinguishing chamber 17, and the arc extinguishing is established as a whole. The probability of doing is improved. Since the gas flowing into the recesses 181, 182, 183 does not exit to the external space, the radial arc extinguishing hole 23 is
If the arc 3 is not extinguished before it goes out of the outer space 3 further, the gas in the arc extinguishing chamber 17 including the concave portions 181, 182, 183 escapes to the external space while being secured inside. Therefore, there is no effect of reducing the gas pressure rise in the arc-extinguishing chamber 17 and there is no hindrance to the arc-extinguishing operation after the radial direction arc-extinguishing hole 23 comes out to the external space.

FIG. 4 is a sectional view of a gas switch immediately after the start of a shut-off operation according to a fourth embodiment of the present invention. The same components as those in FIG. A duplicate description is omitted by adding a D. The difference between FIG. 4 and FIG. 12 is that the fixing portion 1D in FIG. 4 is provided with an arc-extinguishing hole closing bar 19 made of an insulating material. Arc extinguishing hole closing rod 1
Reference numeral 9 denotes an upper portion of the figure, one end of which is fixed to the pedestal 11 and the other end is arranged so as to be inserted into the axial direction arc extinguishing hole 22 of the arc extinguishing hole 21. The gas flow to 22 is shut off. Only when the movable contact 2D moves further down than in the drawing and the arc extinguishing hole closing bar 19 comes out of the axial extinguishing hole 22, the external space passes from the axial extinguishing hole 22 through the radial extinguishing hole 23. A gas stream exiting at the outlet.
Therefore, by appropriately selecting the length of the arc extinguishing hole closing bar 19, the position of the movable contact 2D where the gas flow occurs can be set. When the movable contact 2D is in the position shown in FIG. 11, that is, when the gas switch is in the closed state, the arc-extinguishing hole closing bar 19 is
It is a hole provided so as not to hit D. The movable contact 2D is different from the movable contact 2 in FIG. 11 in that the axial hole 221 is provided.

FIG. 5 is a sectional view of the gas switch of FIG. 4 showing a state immediately before the arc is extinguished, and the components are exactly the same as those of the gas switch of FIG. In this figure, the arc-extinguishing hole blocking rod 19 has already exited the axial arc-extinguishing hole 22 and a gas flow 4 has occurred, which results in an arc 3
Is drawn into the axial direction arc extinguishing hole 22, and thereafter, the arc 3 is extinguished, the arc is extinguished, and the gas switch is in an "open" state. Since the arc-extinguishing hole closing rod 19 is made of an insulating material, it hardly affects the behavior of the arc 3 even if it is at the position shown in FIG.

If the length of the arc extinguishing hole closing bar 19 is appropriately selected, the position of the movable contact 2D at which the gas flow 4 passing from the arc extinguishing chamber 17 through the axial arc extinguishing hole 22 can be appropriately set as described above. Therefore, a gas flow can be generated at a position where the gas pressure in the arc-extinguishing chamber 17 is sufficiently increased, and the arc can be surely extinguished. FIG. 6 is a cross-sectional view of a gas switch according to a fifth embodiment of the present invention immediately before an arc is extinguished, and the same members as those in FIG. The difference between FIG. 4 and FIG. 4 is that the arc extinguishing hole closing rod 1 made of the insulating material of FIG.
9 in that a metal arc extinguishing rod 19E is used instead of 9 and that the position of the exit of the radial arc extinguishing hole 23 of the movable contact 2 is immediately after exiting from the nozzle hole 144 of the insulating nozzle 14 to the external space. It is. The arc extinguishing rod 19E is provided at the tip with the arc-resistant metal 1 of the fixed contact 1 and the movable contact 2E.
An arc-resistant metal 191 made of the same material as that of 22 or 24 is provided.

When the movable contact 2 is located at the same position as in FIG. 11, that is, when the gas switch is turned on, the arc extinguishing rod 19E is inserted into the axial arc extinguishing hole 22 of the movable contact 2. Then, after the breaking operation is started and the tip of the movable contact 2 is separated from the fixed contact 12, that is, near the position of the movable contact 2 in FIG. Get out. Therefore, as in the fourth embodiment, the arc extinguishing rod 19E does not actually expect the action of closing the axial arc extinguishing hole 22 to delay the generation of the gas flow.

Even when the movable contact 2 is separated from the fixed contact 12, no arc is generated between the arc-resistant metal 122 and the arc-resistant metal 24, and the arc extinguishing rod 19E inserted in the axial arc extinguishing hole 22 and The conductive state is maintained between the movable contact 2 and the arc is generated between the arc-resistant metal 191 of the arc extinguishing rod 19E and the movable contact 2 when the arc extinguishing rod 19E is separated from the movable contact 2.

Further, when the movable contact 2 moves downward to reach the position shown in FIG. 6 and the radial arc extinguishing hole 23 communicates with the external space, the same gas flow 4 as shown in FIG. 13 is generated. Is extinguished. At this time, the arc-resistant metal 191 at the tip of the arc extinguishing rod 19E is located at the center of the axis close to the axial direction arc extinguishing hole 22, so that the arc 3 is moved to the axial direction arc extinguishing hole 2 as shown in the figure.
The arc is more easily absorbed, so that the arc can be more reliably extinguished.

The end of the arc on the fixed portion 1E side is an arc extinguishing rod 19
Since the arc-resistant metal 191 at the tip of E is used, the fixed contact 12 is not worn by the arc. Although the arc resistant metal 122 is shown in this figure, it may be omitted in practice. The fixed contact 12 is formed by integrating small pieces divided in the circumferential direction as described above by a spring 121. In the conventional one, each piece is provided with an arc-resistant metal 122. In the current interruption phenomenon, the end of the arc 3 on the fixed portion 1 side may not always be on the arc-resistant metal 122 but may also move to the fixed contact 12 in another portion. The portion of the fixed contact 12 other than the arc-resistant metal 122 is made of copper,
It is easily worn by an arc and has a fixed contact 1
The problem of the conventional example is that there is a possibility that a problem that the adjacent small pieces are welded to each other and the pressing action of the spring 121 on the movable contact 2 is obstructed may occur, which is a problem of the conventional example. Problems can be avoided.

FIG. 7 is a cross-sectional view of a gas switch according to a sixth embodiment of the present invention immediately before the end of the shut-off operation. The same components as those in FIG. 6 are denoted by the same reference numerals, and redundant description will be omitted. 7 is different from FIG. 6 in that an arc-extinguishing tube 19F made of a tubular metal is provided in FIG. 7 instead of the arc-extinguishing rod 19E in FIG. The upper side of the figure of the inner hole of the arc-extinguishing cylinder 19F is open to the outer space. Therefore, when the gas pressure in the arc extinguishing chamber 17 rises, the arc extinguishing hole 21 of the movable contact 2
In addition to the gas flow 4 passing through the arc, the gas flow 42 passing through the arc-extinguishing tube 19B to the upper external space is generated, and the arc 3 is not only drawn into the axial arc-extinguishing hole 22 by the gas flow 4 but also extinguished. It is drawn into the arc tube 19F. Therefore,
The arc 3 is more reliably extinguished.

FIG. 8 is a sectional view of a gas switch immediately before the end of a shut-off operation according to a seventh embodiment of the present invention. The same components as those in FIG. A duplicate description is omitted by attaching a G. 8 differs from FIG. 7 in that a pressure relief valve 192 is provided in the inner hole of the arc-extinguishing cylinder 19F. As in the case of the pressure relief valve 25 of FIG. 1 and the pressure relief valve 25A of FIG. 2, the pressure relief valve 192 is opened only when the gas pressure in the arc-extinguishing chamber 17 reaches a certain value or more, and the gas corresponding to the gas flow 42 of FIG. Flow occurs. Although the movable contact 2 is not provided with the pressure relief valves 25 and 25A as shown in FIGS. 1 and 2, one of these may be used together with the pressure relief valve 192.

FIG. 9 is a sectional view of a gas switch immediately after the start of a shut-off operation according to an eighth embodiment of the present invention. In FIG. 9, the same components as those in FIG. The description is omitted by adding H. The difference between FIG. 9 and FIG. 12 is that the axial length of the arc extinguishing hole 22H is increased and the outlet of the radial arc extinguishing hole 23H is provided at a position away from the tip of the movable contact 2H. Recess 16
Is that the tip of the arc extinguishing hole 22H on the arc extinguishing chamber 17 side is formed in a funnel shape to form a funnel-shaped portion 221.

The gas pressure in the arc-extinguishing chamber 17 due to the arc 3 does not increase until the movable contact 2H separates from the fixed contact 12 from the "closed" state shown in FIG. As the volume of the arc-extinguishing chamber 17 increases by lowering in the lower part of the figure, the pressure decreases accordingly. Both the conventional example and the above-mentioned embodiment do not refer to such a decrease in the gas pressure, but focus on only the heating of the gas by the arc 3 and the increase in the gas pressure accompanying the heating. In the eighth embodiment, on the contrary, the arc extinguishing effect is improved by focusing on the gas pressure drop before the arc 3 is generated.
Since the degree of the pressure drop in the arc-extinguishing chamber 17 due to the movement of the movable contact 2H becomes larger as the volume of the arc-extinguishing chamber 17 when the gas switch is in the "closed" state becomes larger, the concave portion 16 is eliminated. Things.

FIG. 9 is a view similar to FIG.
This is a state immediately after the movable contact 2H is mechanically separated from the contact and the arc 3 is generated. At this point, the radial direction arc extinguishing hole 23H has already been in communication with the external space.
As a result, a gas flow 43 which enters the arc-extinguishing chamber 17 from an external space opposite to the above-mentioned gas flow 4 is generated as shown.
The arc 3 immediately after the generation is extinguished by the gas flow 43. Gas flow 44 ejected from the tip of the axial arc extinguishing hole 22H
Since the extinguishing action of the arc 3 becomes stronger when there is a flow component in the radial direction, a funnel-shaped portion 221 in which the shape of the axial arc-extinguishing hole 22 in this portion is funnel-shaped is formed as shown in FIG. The flow 43 is made to spread in the radial direction. However,
Even if the funnel-shaped part 221 is not provided, the existence of the funnel-shaped part 221 is not essential to the present invention because the gas flow 44 can extinguish the arc. If the funnel-shaped portion 221 is not provided, the gas flow ejected into the arc-extinguishing chamber 17 has a large component that goes straight in the axial direction, but this component pulls the surrounding gas to generate a wider gas flow, and the arc 3 Acts to extinguish the arc.

According to the eighth embodiment, since the arc 3 can be extinguished before the arc 3 greatly develops, the wear of the arc-resistant metals 122 and 24 is small, which contributes to the extension of the life of the gas switch. be able to. FIG. 10 is a cross-sectional view showing a ninth embodiment of the present invention when the gas switch is "closed". The same components as those in FIG. And duplicate explanations are omitted. FIG. 10 shows a state where the movable contact 2I is stopped while the gas switch is in the “closed” state as in FIG. The difference between FIG. 9 and FIG. 9 is that the axial dimension of the arc extinguishing chamber 17I is increased, and the movable contact 2I is correspondingly increased.
The point that the protrusion dimension from the contact portion with the fixed contact 12 is increased.

As shown, the movable contact 2I is connected to the arc-extinguishing chamber 1.
It is in a state where the volume of the gas space is reduced by protruding into 7I. From this state, the breaking operation is started, and when the movable contact 2I separates from the fixed contact 12 and the arc 3 is generated as shown in FIG. 9, the state of "closed" and the state at this time are compared with the case of FIG. Since the volume change of the arc-extinguishing chamber 17 is larger than that of the eighth embodiment in FIG. 9, the amount of pressure drop is also large, and therefore, the gas flows corresponding to the gas flows 43 and 44 in FIG. As a result, the arc extinguishing effect is further improved, and the arc 3 can be extinguished immediately after the arc is generated.

In FIGS. 9 and 10, the shape of the widening portion of the opening of the axial arc extinguishing hole 22 to the arc extinguishing chambers 17H and 17I does not extend linearly like a funnel, for example. Like a trumpet, the opening may have a widened portion in which the spread of the opening is curved and the spread ratio increases toward the tip.

[0035]

As described above, according to the present invention, if a pressure relief valve that closes the arc extinguishing hole and opens when the gas pressure in the arc extinguishing chamber exceeds a predetermined value is provided in the arc extinguishing hole, the arc extinguishing chamber becomes invisible. Only when the gas pressure reaches a predetermined value, the pressure relief valve opens to generate a gas flow and the arc-extinguishing function works. Therefore, it is possible to eliminate the problem that a gas flow having a low gas pressure does not generate a gas flow having a strength required for arc-extinguishing. Is obtained. The same effect can be obtained by providing the pressure relief valve in the axial arc extinguishing hole or in the radial arc extinguishing hole.

By forming at least three protrusions and at least two recesses interposed between the protrusions on the insulating nozzle, the arc-extinguishing chamber and the arc-extinguishing chamber are formed when the opening of the radial arc-extinguishing hole reaches one recess. When a gas flow corresponding to the gas pressure difference between the concave portion and the cut-off current is small, the arc can be extinguished by this gas flow to achieve arc extinction. Since a plurality of concave portions are provided, even if arc extinguishing is not established in the first concave portion, the arc is extinguished by the gas flow to the next concave portion, so that an effect of increasing the possibility of arc extinguishing is obtained. Even if the breaking current is large and the arc is not extinguished by the gas flow to the recess, the gas in the arc extinguishing chamber does not flow out of the insulating nozzle, so the opening of the radial arc extinguishing hole is the space outside the insulating nozzle. The gas in the arc-extinguishing chamber communicates with the gas and does not cause a decrease in the gas pressure with respect to the gas flow flowing to the external space.

An arc-extinguishing hole closing rod made of an insulating material is attached to the fixed portion at a position where the arc-extinguishing hole is inserted into the movable contact in the axial direction.
If the arc extinguishing hole blocking rod closes the axial arc extinguishing hole to the position where it exits the axial arc extinguishing hole, even if the opening of the radial arc extinguishing hole comes out of the insulating nozzle, the arc extinguishing chamber Gas flow from the outside to the outside does not occur, and it is possible to wait for the gas pressure in the arc-extinguishing chamber to further increase by delaying the occurrence of the arc-extinguishing action by the gas flow, so that in the case of a large breaking current, the arc is surely extinguished, Can be shut off.

If a metal arc extinguishing rod is provided in place of the arc extinguishing hole closing rod, the starting point of the arc on the fixed part side becomes the tip of the arc extinguishing rod and the wear of the fixed contact can be reduced. This has the effect of contributing to an improvement in the reliability of the device.
Also, if an arc extinguishing cylinder is provided instead of the arc extinguishing rod, and the inner hole of the arc extinguishing cylinder communicates with the space inside the arc extinguishing chamber and the external space, the gas in the arc extinguishing chamber rises and the A gas flow is generated through the inner hole, and the gas flow causes the arc to be sucked into the arc-extinguishing cylinder, so that the cooling and the arc-extinguishing action are performed as in the case of the axial arc-extinguishing hole. If a pressure relief valve that closes the inner hole of the arc-extinguishing cylinder and becomes “open” when the gas pressure in the arc-extinguishing chamber exceeds a predetermined value is provided, it is the same as the above-described configuration in which the pressure relief valve is provided in the arc-extinguishing hole. In addition, since the gas flow can be prevented from being generated until the gas pressure in the arc-extinguishing chamber exceeds a predetermined value, an effect that the arc-extinguishing function works more reliably can be obtained.

If the opening of the radial arc extinguishing hole is provided at a position where the movable contact communicates with the external space a little after the time when the movable contact is mechanically separated from the fixed contact, the arc has not yet developed at this time. Therefore, the gas pressure in the arc-extinguishing chamber does not contribute to the increase in the gas pressure in the arc-extinguishing chamber. An effect is obtained in that a gas flow flowing from the outlet of the hole toward the arc extinguishing chamber is generated, and the arc can be extinguished by this gas flow. Also, if the ratio of the volume of the movable contact occupying the arc-extinguishing chamber is increased while the gas switch is in the "closed" state, the ratio of the volume increase when the movable contact comes out of the arc-extinguishing chamber due to the start of the shut-off operation is reduced. As the pressure increases, the degree of decrease in gas pressure becomes remarkable, and a larger gas flow can be obtained. Therefore, the effect of increasing the arc extinguishing effect and contributing to reliable current interruption can be obtained. If the opening of the axial arc-extinguishing hole into the arc-extinguishing chamber is formed in a shape that expands toward the arc-extinguishing chamber, for example, in a funnel shape or trumpet shape, the gas flow ejected from this opening has a radially expanding component. Arose,
The initial arc extinguishing action generated at the periphery of the tip of the movable contact is further enhanced, and contributes to more reliable current interruption.

[Brief description of the drawings]

FIG. 1 is a sectional view of a gas switch immediately after the start of a shutoff operation according to a first embodiment of the present invention;

FIG. 2 is a cross-sectional view of a gas switch immediately after a shutoff operation according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a gas switch immediately after the start of a shutoff operation according to a third embodiment of the present invention;

FIG. 4 is a cross-sectional view of a gas switch immediately after the start of a shutoff operation according to a fourth embodiment of the present invention;

FIG. 5 is a sectional view of the gas switch shown in FIG. 4 immediately before the shutoff operation is completed.

FIG. 6 is a cross-sectional view of a gas switch immediately before the end of a shutoff operation according to a fifth embodiment of the present invention.

FIG. 7 is a sectional view of a gas switch immediately before the end of a shutoff operation according to a sixth embodiment of the present invention.

FIG. 8 is a sectional view of a gas switch immediately before the end of a shutoff operation according to a seventh embodiment of the present invention.

FIG. 9 is a cross-sectional view of a gas switch immediately after the start of a shutoff operation according to an eighth embodiment of the present invention.

FIG. 10 is a sectional view of a gas switch when “closed” showing a ninth embodiment of the present invention;

FIG. 11 is a cross-sectional view of a conventional gas switch when “closed”.

12 is a sectional view of the gas switch immediately after the start of the shut-off operation in FIG. 11;

13 is a cross-sectional view of the gas switch immediately before the end of the shut-off operation of FIG. 11;

[Explanation of symbols]

1, 1C, 1D, 1D, 1F, 1G, 1I: fixed part, 1
1, 11F, 11I: pedestal, 12: fixed contact, 1
4, 14C: insulating nozzle; 141: first protrusion, 14
2 Second protrusion, 1421, 1422 1423 Projection, 143, 144 Nozzle hole 18, 181, 18
2,183: auxiliary arc-extinguishing chamber, 19: arc-extinguishing hole closing bar, 19E
... Arc extinguishing rod, 19F ... Arc extinguishing cylinder, 122, 24, 191,
191F: Arc resistant metal, 25, 25B, 192: Pressure relief valve, 2, 2A, 2B, 2D, 2H, 2I: Movable contact, 21, 21H, 21I: Arc extinguishing hole, 22, 22H, 2
2I: axial direction arc extinguishing holes, 23, 22H, 22I: radial direction arc extinguishing holes, 3: arc, 4, 42, 43, 44: gas flow,
221 Funnel-shaped part (spread part)

Claims (11)

[Claims] 1. A fixed part, a movable contact inserted into and contactable with a ring-shaped fixed contact of the fixed part in a container filled with an insulating gas, and an insulation provided over the fixed contact. A nozzle and an arc extinguishing chamber are formed inside the insulated nozzle, and the side of the insulated nozzle into which the movable contact is inserted is narrowed, and a protruding portion having a nozzle hole into which the movable contact is inserted to protrude toward the inner diameter side is provided. Formed in the movable contact, the axial direction arc extinguishing hole provided in the axial end at the tip end on the side inserted into the fixed contact,
In a gas switch provided with an arc extinguishing hole formed of a radial extinguishing hole communicating with the axial arc extinguishing hole and penetrating the movable contact in the radial direction and opening to the outside of the movable contact, A gas switch, wherein a pressure release valve is provided in the arc extinguishing hole to close the hole and open when the gas pressure in the arc extinguishing chamber exceeds a predetermined value. 2. The gas switch according to claim 1, wherein the pressure relief valve is provided in the arc extinguishing hole in the axial direction. 3. The gas switch according to claim 1, wherein the pressure relief valve is provided in the arc extinguishing hole in the radial direction. 4. A fixed part, a movable contact inserted into and contactable with a ring-shaped fixed contact of the fixed part in a container filled with an insulating gas, and an insulating part provided over the fixed contact. A nozzle and an arc extinguishing chamber are formed inside the insulated nozzle, and the side of the insulated nozzle into which the movable contact is inserted is narrowed, and a protruding portion having a nozzle hole into which the movable contact is inserted to protrude toward the inner diameter side is provided. Formed in the movable contact, the axial direction arc extinguishing hole provided in the axial end at the tip end on the side inserted into the fixed contact,
In a gas switch provided with an arc extinguishing hole formed of a radial extinguishing hole communicating with the axial arc extinguishing hole and penetrating the movable contact in the radial direction, at least three protruding portions and these protruding portions are provided on the insulating nozzle. A gas switch, wherein at least two concave portions sandwiched between the portions are formed. 5. A fixed part, a movable contact inserted into and contactable with a ring-shaped fixed contact of the fixed part in a container filled with an insulating gas, and an insulating member provided to cover the fixed contact. A nozzle and an arc extinguishing chamber are formed inside the insulated nozzle, and the side of the insulated nozzle into which the movable contact is inserted is narrowed, and a protruding portion having a nozzle hole into which the movable contact is inserted to protrude toward the inner diameter side is provided. Formed in the movable contact, the axial direction arc extinguishing hole provided in the axial end at the tip end on the side inserted into the fixed contact,
In a gas switch provided with an arc extinguishing hole consisting of a radial arc extinguishing hole communicating with the axial arc extinguishing hole and penetrating the movable contact in the radial direction, the gas switch is inserted into the axial arc extinguishing hole of the movable contact. The arc extinguishing hole closing rod made of insulating material is attached to the fixed part at a position where the movable contact separates from the fixed contact in the predetermined position during the breaking operation. A gas switch characterized by being formed in a gas switch. 6. A gas switch according to claim 5, further comprising a metal arc extinguishing rod in place of the arc extinguishing hole closing rod.
A gas switch characterized in that it is formed to have a length that comes out of an axial arc-extinguishing hole of a movable contact when a fixed contact and a movable contact are mechanically separated during a breaking operation. 7. The gas according to claim 6, wherein an arc-extinguishing cylinder is provided in place of the arc-extinguishing rod, and an inner hole of the arc-extinguishing cylinder communicates the interior of the arc-extinguishing chamber with the external space. Switch. 8. The pressure relief valve according to claim 7, further comprising a pressure relief valve that closes an inner hole of the arc extinguishing cylinder and opens when the gas pressure in the arc extinguishing chamber exceeds a predetermined value. Gas switch. 9. A fixed part, a movable contact inserted into and contactable with a ring-shaped fixed contact of the fixed part in a container filled with an insulating gas, and an insulating part provided over the fixed contact. A nozzle and an arc extinguishing chamber are formed inside the insulated nozzle, and the side of the insulated nozzle into which the movable contact is inserted is narrowed, and a protruding portion having a nozzle hole into which the movable contact is inserted to protrude toward the inner diameter side is provided. Formed in the movable contact, the axial direction arc extinguishing hole provided in the axial end at the tip end on the side inserted into the fixed contact,
In a gas switch provided with an arc extinguishing hole formed of a radial extinguishing hole communicating with the axial arc extinguishing hole and penetrating the movable contact in the radial direction, the opening of the radial extinguishing hole is movable. 2. The gas switch according to claim 1, wherein the gas switch is provided at a position communicating with the external space at a point in time when the contact is mechanically separated from the fixed contact by a predetermined time. 10. The gas switch according to claim 9, wherein when the gas switch is in a "closed" state, a ratio of a volume of the movable contact in the arc-extinguishing chamber is increased. 11. The gas switch according to claim 9, wherein an opening of the axial arc extinguishing hole into the arc extinguishing chamber forms a widened portion that extends toward the arc extinguishing chamber.