JP2000348577A - Gas switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prolong lifetime of a contacting piece. SOLUTION: A fitting hole 15 having an opening 18 on the side with a movable arc contacting piece is provided, in a stationary arc contacting piece 2A at its forefront in the axial direction, and into this hole 15 a contact member 16 is fitted, in such a way as to be capable of moving in the axial direction, and the width X of the opening 18 is made smaller than the width Y of contact member 16 in the radial direction, and the contact member 16 is energized at all times towards the movable arc contacting piece by a resilient member 14 which is installed inside the fitting hole 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an SF ₆ gas switch, and more particularly, to a gas switch such as a circuit breaker, a disconnector, and a ground switch having a long contact life.

[0002]

2. Description of the Related Art FIG. 3 is a sectional view of a main part of a conventional gas switch, showing the structure of a gas circuit breaker. A first contact, that is, a fixed arc contact 2, and a second contact, that is, a movable arc contact 6, are housed in an SF ₆ gas tank (not shown) so as to be able to approach and separate from each other. The fixed arc contact 2 is formed in a rod shape and is formed integrally with the fixed energizing contact 1. On the other hand, the movable arc contact 6 is formed in a cylindrical shape and is fixed to the exhaust cylinder 8. A puffer cylinder 7 is fixed to the outer periphery of the exhaust cylinder 8, and a fixed energizing contact 5 and a first insulating nozzle 3 are fixed to the left end of the puffer cylinder 7.
Further, a second insulating nozzle 4 is provided inside the first insulating nozzle 3.
The second insulating nozzle 4 is fixed to the movable arc contact 6.

In FIG. 3, a fixed arc contact 2 and a fixed energizing contact 1 are always fixed to an SF ₆ gas tank side, and a movable energizing contact 5 integrated with a movable arc contact 6, an exhaust cylinder 8, a puffer cylinder 7, The first insulating nozzle 3 and the second insulating nozzle 4 are movable left and right in FIG. The movable part integral with the movable arc contact 6 is driven at the time of closing or closing by a driving device (not shown) provided on the right side of FIG. FIG. 3 shows a state in the middle of the breaking operation, in which the movable part integral with the movable arc contact 6 is moving rightward.

FIG. 4 is a sectional view of an essential part showing the structure of the first contact of FIG. 3, that is, the fixed arc contact 2. As shown in FIG. The contact member 13 is joined to the right end of the fixed arc contact 2, that is, the side facing the movable arc contact (not shown).

Returning to FIG. 3, the breaking mechanism of the circuit breaker will be described next. At the time of closing, the movable part integral with the movable arc contact 6 is located a little further to the left in FIG. 3, and the contact member 13 of the fixed arc contact 2 is fitted into the inside of the movable arc contact 6 and the fixed energization is performed. The contact 1 is in contact with the movable contact 5. For this purpose, the current flowing through the circuit breaker at the time of closing is shunted to both the fixed current-carrying contact 1 and the movable current-carrying contact 5 and the fixed arc contact 2 and the movable arc-contact 6. When the cutoff command is issued, the above-described driving device operates, and the movable part integrated with the movable arc contact 6 is driven rightward. Accordingly, the pressure in the puffer chamber 9 surrounded by the puffer cylinder 7 and the exhaust cylinder 8 increases. This is because the inner surface of the puffer chamber 9 is gradually reduced with the operation of the driving device because the right side of the puffer chamber 9 is sealed by a fixed piston (not shown). When the movable part integral with the movable arc contact 6 further moves to the right, first, the fixed energizing contact 1 and the movable energizing contact 5 are separated. At this time, the fixed arc contact 2 and the movable arc contact 6 are configured so as not to be separated from each other. Therefore, since the current flows through the fixed arc contact 2 and the movable arc contact 6, no arc is generated in the separation gap 17 between the fixed current contact 1 and the movable current contact 5. For this reason, the fixed energizing contact 1 and the movable energizing contact 5 do not wear out. When the movable part integral with the movable arc contact 6 further moves to the right, the fixed arc contact 2 and the movable arc contact 6 start to separate, and an arc 11 is generated in the separation gap 12. Become. The high pressure gas accumulated in the puffer chamber 9 is supplied to the arc 11 through the puffer hole 10 and the second insulating nozzle 3 and the second insulating nozzle 3.
It is sprayed by passing between the insulating nozzles 4. This high-pressure gas cools the arc 11 and increases the opening gap 12, so that the arc 11 is extinguished. The interruption is completed when the movable part integral with the movable arc contact 6 moves further to the right than the state shown in FIG.

As described above, an arc 11 is generated between the fixed arc contact 2 and the movable arc contact 6, so that
A contact member 13 made of a material that is unlikely to evaporate due to arc heat is joined to the tip of the fixed arc contact 2 so that contact wear hardly occurs. The fixed arc contact 2 in FIG. 4 is made of copper having good conductivity, but the material of the contact member 13 is an alloy of tungsten and copper. By including tungsten in copper, the material becomes more difficult to evaporate, so that the life of the fixed arc contact 2 is extended. The fixed arc contact 2 and the contact member 13 are joined by friction welding. Friction welding is joining by pressing another metal against the surface of a metal heated to a high temperature by frictional heat. For example, the contact member 13 rotated at a high speed is brought into contact with the fixed arc contact 2 in the fixed state. Thereby, the contact surface becomes hot due to frictional heat. In this state, when the rotation of the contact member 13 is stopped and the contact member 13 is pressed against the fixed arc contact 2, the fixed arc contact 2 and the contact member 13 are joined. Although a contact member (not shown) is attached to the movable arc contact 6 side in FIG.
When the contact member 13 is worn out, the separation gap 12 becomes larger than the set dimension, so the contact member 13 of the fixed arc contact 2 is more important. That is, the separation gap 12
Is larger than the set dimension, the separation gap 12 is formed before the time when the separation gap 17 is formed at the time of interruption, and there is a possibility that an arc is generated in the separation gap 17.

Next, FIG. 5 is a cross-sectional view of a main part showing a configuration of a different conventional gas switch, showing a configuration of a gas disconnector. FIG. 5 shows a state in which the gas disconnector has started the shutoff operation. In this figure, the main part of the gas disconnector comprises a fixed part and a movable part.

The movable part is a first contact formed in a rod shape,
That is, the movable contact 106 is constituted by a movable contact 106, but an actual gas disconnecting switch is provided with a drive mechanism for driving the movable contact 106 in the left-right direction in the drawing.

The fixed portion is provided on the base 141, the second contact, ie, the fixed contact 102, the metal shield 140 having the opening 140A, and the insulator provided on the opening 140A of the metal shield 140 and having the opening 130A. The fixed contact 102 is composed of divided pieces divided in the circumferential direction, and is pressed toward the inner diameter side by a spring 121 provided on the outer periphery of the plurality of divided pieces to be integrated. The fixed part is housed in a SF ₆ gas tank (not shown) together with the movable part.

When the movable contact 106 penetrates, the inner diameter of the fixed contact 102 is widened, and the movable contact 106 and the fixed contact 102 are fixed at a predetermined pressure by the compression force of the spring 121. Are kept in electrical and mechanical contact. The contact member 202 is a fixed contact 10
2 is provided for each of the two divided pieces, and one end of the arc generated at the time of the breaking operation is connected to the contact member 202.
Formed. Similarly, a contact member 113 is also provided at the tip of the movable contact 106, and the end of the arc on the movable portion side is formed on the contact member 113.

FIG. 6 is a sectional view of a main part showing the structure of the first contact, ie, the movable contact 106 in FIG. The contact member 113 is joined to the right end of the movable contact 106, that is, the joining surface 201 on the side facing the fixed contact 102 (not shown).

Returning to FIG. 5, the shut-off mechanism of the gas disconnector will be described below. FIG. 5 shows a state of the gas disconnector when the gas disconnector starts the shut-off operation, the movable contact 106 is driven to the left in the drawing, and the tip is still in the arc-extinguishing chamber 142. Although the fixed contact 102 and the movable contact 106 are mechanically separated from each other as shown in the figure, since they are electrically connected by the arc 111, this gas disconnector is electrically connected. 5, the arc 111 is formed between the contact member 202 on the fixed contact 102 side and the contact member 113 on the movable contact 106 side in FIG. When the pressure of 142 is heated by the arc 111 and rises, the tip of the movable contact 106 moves further to the left than in the state shown in the drawing and escapes to the external space in a steady pressure state outside the arc-extinguishing chamber 142. Between the arc extinguishing chamber 142 and the external space Due to the force difference, a gas flow is generated from the arc extinguishing chamber 142 toward the external space, and the gas flow cools the arc 111, thereby extinguishing the arc 111, and further moving the movable contact 106 to a predetermined position in the left direction. This completes the shutoff.

As described above, since the arc 111 is generated between the movable contact 106 and the fixed contact 102, the tip of the movable contact 106 is evaporated by the arc heat so that the contact is hardly worn. A contact member 113 made of a material that is difficult to perform is joined. The portion of the movable contact 106 shown in FIG.
Is an alloy of tungsten and copper. The inclusion of tungsten in copper makes the material less likely to evaporate, so that the life of the movable contact 106 is extended. The movable contact 106 and the contact member 113 are joined by friction welding as in the case of the fixed arc contact in the gas circuit breaker of FIG. The gas grounding switch also has a main part and a rod-shaped first contact, that is, a movable contact having the same configuration as that of the gas disconnector described with reference to FIGS.

[0014]

However, the conventional device as described above has a rod-shaped first contact, that is, a fixed arc contact of a gas circuit breaker or a movable contact of a gas disconnector and a gas ground switch. There is a problem that the life of the device cannot be further extended.

That is, the contact member made of an alloy of copper and tungsten becomes more difficult to evaporate when the proportion of tungsten is increased. However, when the proportion of tungsten is increased, the adhesive strength due to friction welding decreases. for that reason,
The proportion of tungsten in the material of the conventional contact member is determined at the limit where the adhesive strength is secured, and the life of the contact member cannot be further extended. If the rod-shaped first contact of the gas switch can have a longer life, the replacement time of the contact of the gas switch can be extended, and the maintenance of the gas switch can be facilitated. It is an object of the present invention to extend the life of a contact as compared with the related art.

[0016]

According to the present invention, there is provided a rod-shaped first contact and a second contact which comes into contact with and separates from an axial end of the first contact. In the gas switch having a contact member made of an arc-resistant material attached to the distal end, a fitting hole having an opening formed on the second contactor side is provided at the distal end. The contact member is fitted into the fitting hole so as to be movable in the axial direction, and the opening width of the opening is formed smaller than the radial width of the contact member, and is provided in the fitting hole. It is preferable that the contact member is always urged toward the second contactor by the elastic member provided. Thus, the contact member can be provided at the tip of the first contact without frictional pressure contact. Therefore, it is possible to select a contact member that is less likely to evaporate, and it is possible to prolong the life of the first contact. Further, even if the contact member is worn, the contact member is pushed out to the second contact side by the elastic body, so that the separation gap between the first contact and the second contact becomes larger than the set dimension. Nor.

In such a configuration, the material of the contact member may be graphite. Graphite is a material that is very difficult to evaporate, but is a material that is difficult to friction weld with copper. According to the configuration of the present invention, since the contact member can be provided at the tip of the first contact without frictional pressure contact, it is possible to use graphite, which is a material that is extremely difficult to evaporate, as the material of the contact member. First
Contact life can be extended.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments. FIG. 1 is a sectional view of a main part showing a configuration of a first contact of a gas switch according to an embodiment of the present invention, and shows a configuration of a fixed arc contact of a gas circuit breaker. The configuration of the gas switch according to the present embodiment other than the first contact is the same as the configuration of the conventional gas switch of FIG. In FIG. 1, a contact support 19 is friction-welded to the right end of a rod-shaped first contact, that is, a fixed arc contact 2A, and a fitting hole 15 is formed inside the contact support 19. The fitting hole 15 is provided with an opening 18 on the right side of the movable arc contact (not shown). A contact member 16 composed of a cylindrical portion 16A and a truncated conical portion 16B is fitted into the fitting hole 15. Mating hole 15
Has an inner wall with a constant radius, and the right side of the inner wall has an opening 1
It is configured to become narrower as going to 8.
The axial length of the cylindrical portion 16A of the contact member 16 is formed shorter than the axial length of the inner wall having a constant radius of the fitting hole 15, and the contact member 16 is guided by the fitting hole 15 to extend in the axial direction. It is movable. An elastic body 14 such as a coil spring is interposed between the fixed arc contact 2A and the contact member 16, and constantly biases the contact member 16 rightward.

In FIG. 1, since the opening width X of the opening 18 is smaller than the diameter Y of the cylindrical portion 16A of the contact member 16, the contact member 16 does not come out of the fitting hole 15. In addition, even if the right end of the contact member 16 is worn out by an arc, the contact member 16 moves to the right side.
Is always at the position of the opening 18 of the fitting hole 15,
A first contact, that is, a fixed arc contact 2A;
The gap between the contact and the movable arc contact never exceeds the set dimension. Further, since the arc mainly concentrates on the center of the right end of the contact member 16 in the opening 18, if the material of the contact member 16 is made of a material that is more difficult to evaporate than ever before, the fixed arc contact 2A
Can be further extended. Since there is no need to frictionally contact the contact member 16 and the fixed arc contact 2A made of copper, for example, as a material of the contact member 16, an alloy of copper and tungsten in which tungsten is contained in a proportion higher than that of a conventional material, or tungsten alone Can be used. Further, as the material of the contact member 16, graphite which cannot be friction-welded with copper can be used. Since graphite is a material that is less likely to evaporate than an alloy of copper and tungsten, the life of the fixed arc contact can be extended by using graphite as the material of the contact member 16.

In FIG. 1, the contact support 19 is preferably made of an alloy of copper and tungsten in order to make it difficult to evaporate due to arc heat, but is not exposed to the arc as much as the contact member 16. Therefore, the ratio of tungsten in the alloy used as the material of the contact support 19 can be set to a ratio of bonding with sufficient strength to copper by friction welding. Further, since the contact support 19 is shaped to wrap the right side of the contact member 16, the contact support 19 can be easily formed with a rounded right end, and the electric field at the end can be reduced. Therefore, the fixed arc contact 2
The dielectric strength between A and the movable arc contact does not decrease as compared with the conventional case.

Next, FIG. 2 is a sectional view of a main part showing a configuration of a first contact of a gas switch according to a different embodiment of the present invention, and shows a configuration of a movable contact of a gas disconnector. I have. Note that the configuration of the portion other than the first contact in the gas switch according to the present embodiment is the same as the conventional configuration of FIG. The configuration of the axial end portion of the movable contact of the gas disconnector of FIG. 2 is the same as the configuration of the fixed arc contact of the gas circuit breaker of FIG. 1 described above. A contact support 119 is friction-welded to the right end of the rod-shaped first contact, ie, the movable contact 106A, and a fitting hole 115 is formed inside the contact support 119. The fitting hole 115 is provided with an opening 118 on the right fixed contactor side (not shown). A contact member 116 composed of a cylindrical portion 116A and a truncated conical portion 116B is fitted in the fitting hole 115. The fitting hole 115 has an inner wall with a constant radius, and the right side of the inner wall is configured to become narrower toward the opening 118. The axial length of the cylindrical portion 116 </ b> A of the contact member 116 is formed shorter than the axial length of the inner wall having a constant radius of the fitting hole 115.
And can be moved in the axial direction. An elastic body 114 such as a coil spring is interposed between the fixed contact 106A and the contact member 116, and constantly biases the contact member 116 rightward.

In FIG. 2, the opening width X1 of the opening 118 is shown.
Is smaller than the diameter Y1 of the columnar portion 116A of the contact member 116, the contact member 116 does not come out of the fitting hole 115. Moreover, even if the right end of the contact member 116 is worn out by an arc, the contact member 116 moves to the right, so that the right surface of the contact member 116 is always at the position of the opening 118 of the fitting hole 115, and the first The separation gap between the contact, ie, the movable contact 106A, and the second contact, ie, the fixed contact, is never larger than the set dimension. Further, if the material of the contact member 116 is made of a material that is less likely to evaporate than ever before, the life of the movable contact 106A can be further extended. Since the contact member 116 does not need to be friction-welded to the fixed arc contact 106A made of copper, for example, as a material of the contact member 116, an alloy of copper and tungsten containing tungsten in a proportion higher than that of a conventional material, or tungsten alone Can be used. Also,
As a material of the contact member 116, graphite which cannot be friction-welded with copper can be used. Since graphite is a material that is less likely to evaporate than an alloy of copper and tungsten, using graphite as the material of the contact member 116 can extend the life of the movable contact.

The contact support 119 is preferably made of an alloy of copper and tungsten in order to make it difficult to evaporate due to arc heat. In this case, the proportion of tungsten in the alloy is set to a value sufficient for copper by friction welding to have sufficient strength. It is good to make the ratio adhered by.

In the configuration of the movable contact of the gas disconnector shown in FIG. 2, the contact support 119 has a flat end surface without being rounded at the right end thereof. It is different from the configuration of the arc contact. In gas disconnectors, unlike gas circuit breakers, which interrupt large currents, the current to be interrupted is small and the arc generated during the interruption operation is also small, so to improve the insulation characteristics between the movable contact and the fixed contact. Since the electric field at the end of the movable contact 106A does not need to be reduced as much as in the case of the fixed arc contact of the gas circuit breaker, the axial end face of the movable contact 106A should be flat to improve the workability of the contact support 119. It is in the shape.

In the case of the gas grounding switch, the rod-shaped first contact, that is, the movable contact is configured similarly to the movable contact in the gas disconnector described with reference to FIG. The life of the movable contact can be made longer than before.

[0026]

As described above, according to the present invention, a fitting hole having an opening formed on the side of the second contact is provided at the tip of the rod-shaped first contact. The member is fitted so that it can be moved in the axial direction, and the opening width of the opening is formed smaller than the radial width of the contact member, and the contact member is formed of an elastic body provided in the fitting hole. By being constantly urged to the second contactor side,
As the contact member, for example, a material such as graphite which is less likely to evaporate than before can be used, and the life of the first contact becomes longer than before. Further, even if the contact member is worn, the contact member is pushed out to the second contact side by the elastic body, so that the separation gap between the first contact and the second contact becomes larger than the set dimension. Nor. Thereby, the replacement time of the first contact of the gas switch can be extended,
Maintenance of the gas switch is also facilitated.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing a configuration of a first contact of a gas switch according to an embodiment of the present invention.

FIG. 2 is a sectional view of a main part showing a configuration of a first contact of a gas switch according to another embodiment of the present invention;

FIG. 3 is a sectional view of a main part showing a configuration of a conventional gas switch.

FIG. 4 is a sectional view of a main part showing a configuration of a first contact of FIG. 3;

FIG. 5 is a sectional view of a main part showing a configuration of a different conventional gas switch.

FIG. 6 is a sectional view of a main part showing a configuration of a first contact of FIG. 5;

[Explanation of symbols]

2,2A, 102: Fixed arc contact, 6,106,1
06A: movable arc contact, 14, 114: elastic body, 1
5,115: fitting hole, 16, 116: contact member, 18,
118: Opening

Claims (2)

[Claims] A first contact having a rod-like shape; and a second contact which comes into contact with and separates from an axial end of the first contact. The end is made of an arc-resistant material. In the gas switch to which the contact member is attached, a fitting hole having an opening formed on the second contactor side is provided at the distal end, and the contact member is moved in the fitting hole in the axial direction. The contact member is always connected to the second contactor side by an elastic body provided in the fitting hole, and the contact member is always formed to be narrower than a radial width of the contact member. A gas switch characterized by being energized. 2. The gas switch according to claim 1, wherein said contact member is made of graphite.