JPH041973B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vacuum shear breaker which improves its shearing performance by applying a magnetic field parallel to the arc generated during shearing.

Conventionally, many vacuum shield breakers have been proposed that aim to improve the shearing performance by applying a magnetic field parallel to the arc (so-called longitudinal magnetic field) to the arc that occurs between a pair of contacts during shearing. However, this type of vacuum interrupter generally has a coil for generating a magnetic field attached to the vacuum interrupter, which serves as the opening/closing part. , as shown in FIG. 1, in which the coil is integrally provided inside the vacuum container and behind the contact, and as shown in FIG. 2, in which the coil is provided outside the vacuum container.

That is, the vacuum interrupter 1 shown in FIG. 1 includes a pair of lead rods 2a and 2b that hermetically penetrate through a vacuum container 10 comprising an insulator 11, and a high resistance wire is attached to the inner end of each of the lead rods 2a and 2b. It is provided with contacts 3a and 3b via the body 21, and the lead rod 2
a, 2b and the contacts 3a, 3b, a coil electrode 4 that converts the current into a loop current surrounding the lead rods 2a, 2b to generate a magnetic field parallel to the arc;
a and 4b, and at least one lead rod 2b has a bellows 22 between it and the vacuum container 10 so that it can move in the axial direction (vertical direction in the figure).

The vacuum interrupter 1 configured as described above is housed in an insulating frame (not shown), and has a terminal portion at the outer end of each lead rod 2a, 2b that can be freely connected to and separated from the main circuit conductors 8a and 8b. The lead-out conductors 5a and 5b each having a terminal 51 at one end are connected to each other, and an operating device (not shown) is further attached to form a necessary vacuum shield and disconnector.

By the way, the vacuum interrupter constructed as shown in FIG. 1 described above had the following drawbacks.

Since the coil electrodes 4a and 4b are located inside the vacuum vessel 10, there is a drawback that when the coil generates heat due to current flow, it is difficult to dissipate this heat to the outside. It was not appropriate.

Contacts 3a, 3 are provided at the tips of the lead rods 2a, 2b.
b. Since the coil electrodes 4a, 4b and the high-resistance element 21 are integrally joined together by brazing, the number of parts and machining steps are large, and the number of brazing points is large. As a result, the durability was poor.

Therefore, especially in the case of a vacuum interrupter 1 with a large capacity (for high voltage or large current), the contacts 3a, 3
Since the coil electrodes 4a and 4b are large in size and heavy, the impact during operation is large and the durability is significantly reduced.

The coil electrodes 4a, 4b have respective contacts 3a, 3b.
Because it is located on the back of the coil electrodes 4a and 4b, when one of the lead rods 2b moves (moves downward in the figure) during a shear break, the integrated coil electrodes 4a, 4b
The gap will widen. As a result, as the distance between the contacts widens, the lines of magnetic force that were parallel to each other gradually become curved between the pair of contacts 3a and 3b, and the magnetic field effect is attenuated, causing metal vapor to flow from the space between the contacts to the surrounding area. The problem was that the ions diffused, resulting in a shortage of ions needed to maintain the arc, and the shearing performance deteriorated.

From the above, in the vacuum interrupter 1, the coil electrodes 4a and 4b, which generate a vertical magnetic field as shown in FIG. It has become clear that there is a natural limit to the improvement of shearing performance, and that although it is suitable for relatively low-capacity products, it is not suitable for high-capacity products.

For these reasons, for large-capacity vacuum interrupters, the vacuum interrupter shown in Fig. 2, which has been proposed earlier than the vacuum interrupter shown in Fig. 1, has historically been proposed. The technology of a vacuum interrupter in which a vacuum interrupter is disposed outside the vacuum vessel 10 has been reviewed. Next, the vacuum interrupter shown in FIG. 2 will be explained. Items equivalent to those in FIG. 1 are given the same reference numerals, and detailed explanation thereof will be omitted.

That is, only contacts 3a and 3b are provided at the inner ends of the lead rods 2a and 2b, respectively. A coil conductor 4 that generates a vertical magnetic field is wound around the outer periphery of the vacuum container 10, and one winding end of the coil conductor 4 is connected to the fixed lead rod 2a via a connecting lead 6a. It is connected to the outer end, and the other winding end is connected to the lead-out conductor 5 via the connection lead 6b.
It is configured by connecting to a. The vacuum interrupter 1 thus constructed is housed in an insulating frame (not shown) to construct a required vacuum interrupter and disconnector.

By the way, in the case of the vacuum interrupter 1 as shown in Fig. 2, since the coil conductor 4 is provided outside the vacuum vessel 10, even if the coil conductor 4 generates heat due to current flow, it will not be effective. cooled down.

(B) Since the coil conductor 4 is fixed, even if the gap between the pair of contacts 3a and 3b widens when the coil is broken, the magnetic field applied to the arc does not attenuate and remains constant.

○H There are contacts 3 on the inner ends of the lead rods 2a and 2b.
The structure is simple as it is sufficient to provide only a and 3b.

There are various advantages such as:

However, in the conventional vacuum interrupter 1 of this type, the leads 6a and 6b that connect the coil conductor 4 to the lead rod 2a and the lead-out conductor 5a extend the winding ends of the conductor forming the coil conductor 4 as they are. Therefore, the work of individually connecting these connection leads 6a and 6b to the lead rod 2a and the lead-out conductor 5a was very complicated.

Moreover, the connection leads 6a, 6b and the lead rod 2
Since the connections between the vacuum interrupter 1 and the lead-out conductor 5a are integrally connected by fasteners such as bolts and nuts, the vacuum interrupter 1 and the coil conductor 4 may be individually damaged due to the impact when turning on or off. This caused problems such as vibrations, which caused the fasteners to loosen and deteriorate durability.

If the fixing device loosens in this way, the contact resistance at the connection increases, causing heat generation. Furthermore, the current flowing through the coil conductor 4 decreases due to current loss, which adversely affects the generation of the magnetic field, and the shearing performance decreases. When the problem worsened, a problem arose.

The present invention has been made in view of the above points, and solves the problems of the conventional vacuum interrupter in which a coil conductor surrounds the outside of the vacuum interrupter to generate an axial magnetic field. The purpose of this is to improve the properties of the steel and the cutting performance.

To achieve this objective, the present invention provides a coil conductor consisting of a cylindrical coil body with an axial slit in at least one location and at least a pair of radial arms, and the coil conductor is arranged within an insulating frame. The lead rod of the vacuum interrupter is inserted into one arm via an elastic contact, and the lead conductor is connected to the other arm to form a vacuum shield and disconnector.

Next, embodiments of the present invention will be explained based on FIGS. 3 to 6. In these figures, the same reference numerals as in FIGS. 1 and 2 above indicate equivalent products. Therefore, detailed explanation thereof will be omitted.

First, FIG. 3 is a sectional view of the main part of the vacuum shield breaker, showing the configuration for one phase. In this figure, the vacuum container 10 that constitutes the vacuum interrupter 1 is
Insulator (cylindrical) made of glass or ceramics
11 and one end side of this insulator 11 (upper end side in the figure)
an end plate 12 made of metal that seals the insulator 11;
Consists of a cylindrical metal container 13 made of non-magnetic stainless steel provided at the other end (lower end in the figure), and an end plate 14 that closes the end of the metal container 13 (lower end in the figure). has been done.

A fixed lead rod 2a having a contact 3a at the inner end is hermetically penetrated through the one (upper) end plate 12, and the other (lower) end plate 14 is provided with: A movable lead rod 2b having a contact 3b at its inner end is provided via a bellows 22 to constitute the vacuum interrupter 1. Further, the end plate 14 at the lower portion of the vacuum interrupter 1 is provided with a plurality (three) of mounting bolts 15 extending downward in the figure.

In the figure, 16, 17, and 18 are metal shields for relaxing the electric field and trapping metal vapor, respectively.

Next, the coil conductor 4 will be explained based on FIGS. 3 and 4.

As shown in FIG. 3, this coil conductor 4 is provided in the metal container 13 of the vacuum interrupter 1 with a gap therebetween, and is provided so as to surround the pair of contacts 3a and 3b. This coil conductor 4 has a slit 42 at one location, as shown in FIG.
A coil main body 41 formed in a cylindrical shape with approximately one turn, and a coil main body 41 located at one end side (lower end in the figure) in the axial direction of the coil main body 41, and
Both ends (winding ends) 41a and 41b in the arc direction of
A pair of arms (first arm 43 and second arm 4
5) and a first arm provided at the inner end of the first arm 43.
A second arm provided at the inner end of the base 44 and the second arm 45
A base portion 46 is provided.

The first base portion 44 is provided with a through hole 44a having a ring-shaped groove 44b inside. In this groove 44b, there is a resilient contact 4 as shown in FIG.
4c is fitted, and this elastic contact 4
The lead rod 2b on the movable side of the vacuum interrupter 1 is electrically connected to the first base via the lead rod 4c and is inserted through the lead rod 4c so as to be vertically movable.

On the other hand, the second base 46 is provided so as to surround the first base 44 through a space 47, and an elastic contact 46b is fitted inside the second base 46 as shown in FIG. ring-shaped groove 46a
is provided. In addition, this second base 46 includes
The notch 4 is arranged so that it does not come into contact with the first arm 43.
6c is provided. A cylindrical connecting portion 52 provided on a lead-out conductor 5b, which will be described later, is inserted into the second base portion 46 and is electrically connected via an elastic contactor 46b.

The elastic contacts 44c and 46b are well-known ring contacts or multi-contacts, for example.

In FIGS. 3 and 4, the member designated by the reference numeral 48 is
A spacer made of an insulating material such as synthetic resin,
This spacer 48 has two cylindrical parts 4 with different diameters.
A notch 48c is provided in the large-diameter cylindrical portion 48a, which consists of portions 8a and 48b.
As shown in FIG. 3, the spacer 48 configured in this manner has a large diameter cylindrical portion 48a that is connected to the coil conductor 4.
A space 47 between the first base 44 and the second base 46 of
The small-diameter cylindrical portion 48b is inserted into the lead-out conductor 5 to ensure insulation and separation between the first and second base portions.
It is located between the connecting portion 52 of the vacuum interrupter 1 and the movable lead rod 2b of the vacuum interrupter 1 to reliably insulate and separate the two.

Note that the cylindrical portion 48 of this spacer 48 has a particularly small diameter.
The inner shape of the lead rod 2b is not circular but polyhedral or multi-toothed (spline shape).
If the outer shape of the lead rod 2b is shaped to correspond to this, the spacer 48 can be used as a bearing that functions as a guide and a rotation stopper when the lead rod 2b moves up and down.

A lead-out conductor 5b connected to the coil conductor 4
As shown in FIG. 4, in addition to the cylindrical connecting portion 52, the vacuum interrupter 1 is provided with a plurality of (three) through holes 53, and these through holes 53 are provided with mounting bolts provided in the vacuum interrupter 1. 15 is inserted. Further, as shown in FIG. 3, an elastic contact 54 (ring contact or multi-contact) is fitted onto the lead conductor 5a connected to the outer end of the lead rod 2a on the fixed side of the vacuum interrupter 1. The lead rod 2a and the lead conductor 5a are electrically connected via the elastic contactor 54.

Next, the insulating frame 7 in which the vacuum interrupter 1 and the coil conductor 4 described above are housed and fixed will be explained based on FIGS. 3 and 5.

The insulating frame 7 is erected on a pedestal that houses an operating device (not shown) located on the lower side in FIG. 3, for example, and is formed into a substantially cylindrical shape (box shape). has been done. A mounting seat 71 is provided at a predetermined portion of the insulating frame 7 in the vertical direction in the drawing, and a wall portion of the mounting seat 71 on the lower side in the drawing is provided with a mounting seat 71.
A window 72 through which the lead-out conductor 5b is drawn out is provided in an open manner.

The vacuum interrupter 1 and the coil conductor 4 are placed and fixed on the mounting seat 71, and the center of the mounting seat 71 has a through hole into which the second base 46 of the coil conductor 4 is inserted. 73 is provided. The mounting seat 71 is also provided with a plurality (three) of through holes 74 through which the mounting bolts 15 provided on the end plate 14 of the vacuum interrupter 1 pass. Furthermore, on one side of this mounting seat 71 (upper side in Fig. 5)
A ring-shaped groove 76 is provided inside the wall portion 74, and at least the end portion of the coil body 41 of the coil conductor 4 is inserted into this groove 76. The mounting seat 71 is provided with two grooves 77 and 78 positioned in the radial direction so as to connect the ring-shaped groove 76 with the through hole 73 in the center. The first arm 43 and the second arm 45 of the coil conductor 4 are recessed into the coil conductors 77 and 78, respectively.

Note that a pair of grooves 77 and 78 located in the radial direction
The depth dimension A (see FIG. 5) is larger than the height dimension B (see FIG. 3) of the first and second arms 43, 45 of the coil conductor 4, and Therefore, as shown in FIG. 3, when the coil conductor 4 and the vacuum interrupter 1 are installed in the insulating frame 7, the upper surface of the pair of arms 43 and 45 of the coil conductor 4 and the end plate 14 of the vacuum interrupter 1 A gap C is formed between the two.

To explain an example of the assembly and integration work of the vacuum interrupter 1, the coil conductor 4, the banded insulating frame 7, etc. whose structure has been explained in detail above, elastic contact is made in advance in the first base 44 and the second base 46 of the coil conductor 4. The children 44c and 46b are fitted, and a spacer 48 is inserted between both bases.

Then, the coil conductor 4 is inserted from above the insulating frame 7 into the through hole 73 provided in the mounting seat 71 of the insulating frame 7, and the pair of grooves 77, 78 in the radial direction.
The second base 46, the pair of arms 43, 45, and the coil body 41 of the coil conductor 4 are inserted into the ring-shaped grooves 76, and an insulating adhesive or resin is applied to each groove 76. , 77, 78 to integrally connect the coil conductor 4 and the insulating frame 7.

Next, the vacuum interrupter 1 is inserted from above the insulating frame 7, the lead rod 2b of the vacuum interrupter 1 is brought into contact with the elastic contact 44c in the first base 44 of the coil conductor 4, and is passed through the end plate 14.
The mounting bolts 15 provided in the insulating frame 7 are passed through the through holes 73 of the mounting seat 71 of the insulating frame 7, and the end plate 14 is placed in contact with the mounting seat 71.

After such a state, the lead-out conductors 5a and 5b are attached, and one of the lead-out conductors 5b is arranged horizontally penetrating the window 72 of the insulating frame 7, and the connecting portion 52 is connected to the coil conductor. 4
The mounting bolt 15 of the vacuum interrupter 1 is inserted into the through hole 53 and screwed into the nut, thereby connecting the lead conductor 5b to the insulating frame. The vacuum interrupter 1, coil conductor 4, and insulating frame 7 are brought into contact with the lower surface of the mounting seat 71 of 7.
and each member of the lead-out conductor 5b is integrally connected.

The other lead conductor 5a is fixed to the upper wall 79 of the insulating frame 7 with bolts, and the outer end of the lead rod 2a is inserted into and brought into contact with the elastic contact 54 provided, thereby integrally joining. This completes the installation and fixing of the vacuum interrupter 1.

Note that the means for fixing the coil conductor 4 within the insulating frame 7 is not limited to the injection and solidification of adhesive or resin as described above; for example, in FIG. When the vacuum interrupter 1 is fixed with a spacer made of an insulating material that can fill the gap C between the coil conductor 4 and the end plate 14 of the coil conductor 4, the pair of arms 4 of the coil conductor 4
3 and 45 may be fixed by pressure contact. Or, the second of the lead conductor 5b and the coil conductor 4
The coil conductor 4 may be fixed by connecting it to the base 46 with a bolt. According to this, the electrical connection between the two can be made at the same time. The interposed elastic contactor 46b can be omitted.

Further, the coil conductor 4 is not limited to the case where the coil body 41 is formed in approximately one turn shape with one slit 42 as shown in FIG. slits 42a, 4
2b, the coil main body 41 is divided into 1/2, 1/3, and 1/4, and the current can be divided thereby. That is, the coil conductor 4 shown in FIG. 6 is formed into a so-called 1/2 branch current, and the coil body 41 is divided into 1/2 parts by two slits 42a and 42b.
One end of the arc of each coil body 41 is connected to the first base 4 in the center via the first arm 43 in the radial direction.
4, and the other end sides of the arcs are connected via second arms 45 to a second base 46 disposed around the first base 44 with a gap 47,
By dividing the current in this way, the heat generated in the coil conductor 4 is reduced accordingly, making it suitable for a large current circuit breaker.

In the embodiment of the present invention described above, the coil conductor 4 is connected to the movable lead rod 2b and the lead conductor 5b.
Although the present invention is not limited to this, a configuration in which a mounting seat is provided on the insulating frame on the side of the lead-out conductor 5a and the coil conductor 4 is provided connected to the lead rod 2a on the fixed side has been described. There is no problem even if it is. In addition, as for how to install the vacuum interrupter 1, in addition to the case where the movable lead rod 2b is located on the lower side as described above, there is also a case where the lead rod 2b on the movable side is located on the upper side with the reverse arrangement. However, since the coil conductor 4 is relatively heavy, it is desirable to provide it on the lower side from the viewpoint of installation stability.

As is clear from the above description, in the vacuum interrupter according to the present invention, the coil conductor 4 provided surrounding the vacuum interrupter 1 is fixed to the insulating frame 7, and the vacuum interrupter 1 and the coil conductor 4 is connected to coil conductor 4 and lead rod 2.
an elastic contactor 44 that electrically connects b or 2a;
Therefore, even if the lead rod 2b on the movable side of the vacuum interrupter 1 is operated and receives an impact when it is turned on or off, this impact will not be transmitted to the coil conductor 4 and the lead rod 2b. This does not harm the connection relationship between the two, and the coil conductor 4 is not vibrated by this impact, resulting in a marked improvement in the durability of the vacuum shield and disconnector.

Further, since the coil conductor 4 is fixed within the insulating frame 7 and is not integrally connected to the vacuum interrupter 1 side, it is not only possible to assemble the vacuum shield and disconnector easily, but also to make it easier to assemble the vacuum interrupter than the conventional vacuum interrupter. This can be implemented without changing the shape of the Moreover, if the insulating frame 7 is provided with a groove into which the coil conductor 4 can be inserted, positioning and attachment can be easily performed and the coil conductor 4 can be securely fixed. In addition, since almost no shock is transmitted to the coil conductor 4 during opening and closing, the coil conductor 4 is provided between the pair of arms 43 and 45 and between the pair of bases 44 and 4.
6. A spacer made of an insulating material (for example, plastic) can be interposed between them to completely separate them. This eliminates leakage current that flows through the spacer and attenuates the axial magnetic field. .

Furthermore, since the coil conductor 4 and the lead rod 2b or 2a are connected by the elastic contactor 44c, assembly can be easily performed.

[Brief explanation of drawings]

Figures 1 and 2 are schematic explanatory diagrams of a conventional vacuum interrupter, Figure 3 is a sectional view of a vacuum interrupter according to an embodiment of the present invention, and Figure 4 shows the coil electrode and drawer in Figure 3. FIG. 5 is an exploded perspective sectional view of a conductor part, FIG. 5 is a perspective sectional view of a main part of the insulating frame in FIG. 3, and FIG. 6 is a perspective sectional view of a coil conductor according to another embodiment of the present invention. 1... Vacuum interrupter, 10... Vacuum container,
2a, 2b...Lead rod, 3a, 3b...Contact,
4...Coil conductor, 41...Coil body, 42...
...Slit, 43...First arm, 45...Second arm, 44c...Elastic contact, 5a, 5b...Output conductor, 7...Insulating frame.

Claims (1)

[Claims] 1 A pair of opposing lead rods 2a, 2 that hermetically penetrate the vacuum container 10 and can move toward and away from each other.
a vacuum interrupter 1 comprising contacts 3a and 3b at the inner ends of the lead rods 2a and 2b, respectively, and lead-out conductors 5a and 5b connected to the outer ends of the lead rods 2a and 2b; One lead rod 2
a or 2b and the lead-out conductor 5a or 5b, and is arranged so as to be wound around the outer periphery of the vacuum vessel 10, and generates an axial magnetic field parallel to the arc generated between the pair of contacts 3a and 3b. In this vacuum interrupter, the vacuum interrupter 1, the lead-out conductors 5a, 5b, and the coil conductor 4 are held in an insulating frame, and the coil conductor 4 is inserted into the vacuum container 10 through a gap. A coil body 41 surrounding and divided with at least one slit 42;
at least one of the first pairs extending radially inwardly;
and a second arm 45, and is fixed to the insulating frame 7, and the coil conductor 4
One lead rod 2a or 2 of the vacuum interrupter 1 is attached to the inner end of the first arm 43 of the vacuum interrupter 1.
b is inserted through the elastic contactor 44c, and one of the lead-out conductors 5a or 5b is connected to the second arm 45 of the coil conductor 4. vessel.