JPH0211703Y2 - - Google Patents

Description

[Detailed Description of the Invention] Purpose of the Invention (Field of Industrial Application) This invention relates to a mounting structure for a bushing that is inserted into and fixed to a closed type switch such as a gas switch.

(Prior art) Conventionally, bushings that are inserted into and attached to a switch case for each phase are covered with a covered cylindrical bushing cover for each phase on a mounting flange provided on the outer periphery of the bushing. It was fastened and fixed with a fastening member such as a mounting bolt installed in the switch case.

(Problems to be solved by the invention) As mentioned above, in the past, a bushing cover was attached to the mounting flange of the bushing for each phase, and the bushing cover was further tightened and fixed to the switch case. Since the attachment members are also provided in the switch case for each phase, not only the number of parts increases, but also the number of assembly steps increases, resulting in a problem that the efficiency of the switch assembly process deteriorates.

Structure of the invention (Means for solving the problem) In this invention, bushings for each phase are protruded outward from the switch case, and each bushing is connected between a common bushing cover for each phase and the wall of the switch case. In the bushing mounting structure for narrowly fixing the mounting flange, the bushing cover common to each phase is composed of a pair of cover members of the same shape disposed from opposite sides of the mounting flange of the bushing of each phase, and A mounting recess corresponding to the outer peripheral surface of the bushing of each phase is formed in the press plate portion of the cover member,
Furthermore, a protruding piece that overlaps with the pressing plate part of one of the opposing cover members is extended near one end of the pressing plate part, and a mounting recess near the other end side and a mounting recess in the center are provided with a protruding piece that overlaps with the opposing pressing plate part. The gist thereof is that a protruding piece is extended to be overlapped with the cover member.

(Function) With the above configuration, the number of fastening members installed in the switch case can be reduced, and the bushings are firmly pressed and fixed to the case over the entire circumference of each bushing. Furthermore, since the bushing cover for fixing the bushings of each phase is common to each phase, the number of parts is certainly reduced compared to conventional switches. Furthermore, since the bushing cover is formed from the same cover member, it is possible to use common parts.

Also, conventionally there is a structure in which the bushings are attached using a single bushing cover, but in the case of a single bushing cover, it is necessary to insert the bushing insertion holes of each phase from the axial direction of the bushings. Become. However, especially in large-sized switches, the switch case becomes longer, and the common bushing cover also becomes longer. Therefore, in an assembly operation in which a long bushing cover is inserted from the axial direction of the bushing, there is a risk that the periphery of the bushing insertion hole may catch on the outer circumferential surface of the bushing, causing damage. On the other hand, since the present invention arranges a pair of cover members facing each other, the assembly process is simple, in which the mounting recess is arranged from the side to correspond to the mounting flange of the three-phase bushing. There is no need to insert it from the axial direction of the bushing, so there is no risk of damaging the bushing.

Furthermore, the number of man-hours required for manufacturing the switch can be reduced.

(Example) An example in which this invention is embodied in a gas-filled switch will be described below with reference to FIGS. 1 to 4.

Through-holes 1a for bushing are provided in the left and right side walls of the gas-filled switch case 1, which is filled with an arc-extinguishing gas such as SF6, corresponding to each phase, and between each through-hole 1a, as well as on the left and right sides. A pair of upper and lower mounting members 2 are installed at the left and right positions of the through hole 1a, respectively. A screw hole (not shown) is threaded on the distal end surface of the mounting member 2.

Power supply side and load side bushings 3 and 4 are inserted into the through hole 1a. The power supply side bushing 3 and the load side bushing 4 lock a bushing cover C to flanges 3a and 4a formed on their outer peripheries, and are screwed into the screw holes of the mounting member 2 through the bushing cover C. Mounting bolt 5 to be inserted
Fixed by

The bushing cover C is composed of a pair of cover members 6 having the same shape and arranged relative to each other as shown in FIG. That is, the pressing plates 6g of both cover members 6 facing each other are formed with arc-shaped mounting recesses 6a corresponding to the outer circumferential surfaces of the bushings 3 and 4, and the mounting recesses 6a of the opposing pressing plates 6g are also formed near one end. A protruding piece 6b extends through the step so as to overlap the upper surface of the cover member 6.

Further, between the mounting recess 6a of the pressing plate portion 6g and the central mounting recess 6a, a protruding piece 6c is extended laterally through a step so as to be disposed in contact with the upper surface of one of the opposing cover members 6. ing.

A bolt insertion hole 6d for the mounting bolt 5 corresponding to the mounting member 2 is transparently provided in the cover member 6 in a straight line in the longitudinal direction, and the bolt of the corresponding cover member 6 is inserted into the protruding pieces 6b, 6c. A bolt insertion hole 6e through which the mounting bolt 5 common to the hole 6d is pushed is provided. The other three sides of the cover member 6 are formed with cover pieces 6f bent into an L-shape.

Here, an example of how to assemble each phase bushing to the switch case 1 will be explained.

To the outer surface of the flange 4a of the bushing 4,
A pair of cover members 6 are arranged so that the mounting recesses 6a face each other, and the flat parts of the other cover member 6 are overlapped at the step portions provided on the protruding pieces 6b and 6c so that they are flush with each other, and the bolts The insertion holes 6d and bolt insertion holes 6e are made to correspond to each other, and the three-phase bushings are easily and firmly fixed to the case 1 at once by tightening the bolts 5 using the inner surface of the box-shaped bushing cover C.

Therefore, unlike the conventional method, the number of parts is reduced compared to the case where the bushings are individually attached, and the assembly work is simplified.

In addition, the flanges 3a, 4a of the bushings 3, 4
and the cover member 6, and the flange 3a,
Between 4a and the switch case 1, there is a packing 7a,
7b is interposed. Further, an O-ring 1b is airtightly interposed between the inner circumferential surface of the through hole 1a and the bushings 3 and 4.

Additionally, in the case of this type of switch bushing fixing fitting, if a large current flows through the conductor penetrating the bushing, there is a risk that the large current will generate an overcurrent in the fixing fitting and heat the fitting. At the same time, there is a problem that the durability of related parts such as gaskets is reduced.Generally, there is a method of forming the fixing fittings from a non-magnetic material such as stainless steel, but when forming them from iron etc. However, in the case of the structure of the present application, the overlapping part (bolt insertion part) of the cover member 6
By interposing an insulating material such as a resin between the two, it is possible to easily prevent the magnetic closed circuit configuration that generates the eddy current.

Next, the structure of the bushing will be explained. Note that since the structures of the power supply side bushing 3 and the load side bushing 4 are the same, the load side bushing 4 will be explained for convenience of explanation.

Locking steps 9 and 1 are provided in each of the inner and outer ends of the bore 8 which is transparent in the axial direction of the load-side bushing 4.
0 is formed, and within the inner end thereof, an enlarged diameter part 8a that is continuous with the inner cavity 8 and has a diameter larger than that of the inner cavity 8a, and a large diameter part 8b that has a diameter larger than that of the enlarged diameter part 8a.
is formed. The conductive rod 11 inserted into the inner cavity 8 has a bushing 4 on the outer periphery of its outer end.
A locking flange 12 that is locked to the outer end surface of the housing is inserted through and caulked.

A threaded portion 13 is threaded on the outer periphery of the inner end of the conductive rod 11, and a connecting fitting 14 inserted into the enlarged diameter portion 8a is screwed into the threaded portion 13. A locking protrusion 1 circumferentially surrounds the outer circumferential center of the connecting fitting 14.
4a is formed.

A locking fitting 1 that is locked to the locking step 10 is provided between the connecting fitting 14 and the locking step 10.
5. The conductive rod 11 is inserted through the packing 16 and the spring washer 17. Therefore, when the conductive rod 11 is screwed into the connecting fitting 14, the connecting fitting 14 and the locking flange 12 are connected to the bushing 4.
The inner and outer ends of the tube are tightly attached, resulting in a secure attachment.

A sealing member 18 made of an elastic material is provided between the locking flange 12 and the bushing 4 in the conductive rod 11.
is inserted, and the inner end of the sealing member 18 is tightly fitted into the enlarged diameter portion 8c at the outer end of the inner cavity 8. Note that an adhesive such as epoxy resin is applied between the sealing member 18 and the bushing 4.

Furthermore, a buffer ring 20 is interposed between the locking flange 12 and the outer end surface of the bushing 4 on the outside of the sealing member 18. Further, a tapered portion 12b is formed on the inner peripheral edge of the inner end surface of the locking flange 12, and the tapered portion 12b and the sealing member 1
8, an O-ring 18a is interposed therebetween.

As shown in FIG. 1, semicircular arc-shaped anti-rotation protrusions 4b are provided at positions near the outer edge of the outer end surface of the bushing 4 so as to face each other, and between the mutually opposing ends of both anti-rotation protrusions 4b, is a rotation prevention protrusion 12a protruding from the outer periphery of the locking flange 12;
is involved (see Figure 3). Note that a packing 21 is arranged to cover the outer periphery of the locking protrusion 12a. A terminal 22 is fixed to the outer end of the conductive rod 11 by caulking or the like.

A rod-shaped fixed electrode 23 is attached to the inner end surface of the connection fitting 14 by screwing, and is firmly fixed by tightening a nut 24 screwed to the outer periphery of the base end to the connection fitting 14 via a spring washer 25. has been done. The conductive rod 11 has a cap-shaped holding fitting 26 interposed between the spring washer 25 and the connecting fitting 14.
is inserted. A flange 26a is formed on the outer periphery of the tip end of the presser metal fitting 26, and a slight gap is formed between the flange 26a and the inner end surface of the load-side bushing 4.

An O-ring 27 that engages with the locking protrusion 14a is interposed between the outer circumference of the connection fitting 14 and the inner circumference of the large diameter portion 8b of the bushing 4 to maintain airtightness. Furthermore, the O-ring 27 and the presser fitting 26
A spacing regulating ring 28 is inserted between them, and the narrow pressure between the bushing 4 and the connecting fitting 14 equalizes the circumferential pressure applied to the O-ring 27.

Note that the male fixed electrode 29 provided on the power supply side bushing 4 is the same as the fixed electrode 29 on the load side bushing 4.
It is formed to have the same outer diameter as 3, and its length is shorter than that of the load side fixed electrode 23.
As shown in FIG. 2, the fixed electrode 29 is formed with a guide hole 29a whose tip is open, and a through hole 29b communicating with the outside is provided at the base end of the guide hole 29a. The arc-extinguished gas introduced into the guide hole 29a is discharged to the outside of the fixed electrode 29.

The movable electrode section 30 provided on the load-side bushing 4 will be explained with reference to FIG. 3.

The support cylinder 31 constituting the movable electrode section 30 has conductivity and is loosely inserted into the fixed electrode 23 .
Circumferential mounting grooves 31a and 31b are formed in the outer peripheral surface of both ends of the support cylinder 31, and the inner peripheral surface thereof is coated with an insulating synthetic resin such as polytetrafluoroethylene. A plurality of contacts 32 are provided in the mounting groove 31a on the base end side of the support cylinder 31.

The contactor 32 is formed by dividing a conductive cylinder into six parts in the longitudinal direction, the base end being a large diameter part and the distal end part being a small diameter part via a tapered part. Each contactor 32 has a protrusion 33 with an arcuate cross section provided on the inner periphery of its base end, which is rotatably arranged relative to the mounting groove 31a, and a pair of garter springs 34 fitted around the outer periphery of both ends. They are attached to the support cylinder 31 by being bundled together. Furthermore, a protrusion 35 is formed on the inner periphery of the tip of the contactor 32 so as to be in sliding contact with the fixed electrode 23 .

Similarly, a plurality of contacts 36 are provided in the mounting groove 31b of the support cylinder 31.

That is, the contact 36 is formed by dividing a conductive cylindrical body into six in the longitudinal direction, with a large diameter portion at the base end and a small diameter portion at the distal end via a tapered portion. And each contact 3
6 has a protrusion 37 with an arcuate cross section provided on the inner periphery of its base end, which is arranged so as to be rotatable with respect to the mounting groove 31b, and is bundled by a pair of garter springs 38 fitted around the outer periphery of both ends. It is attached to the holding cylinder 31. In addition, the garter spring 3 on the tip side
8 is sheathed with an arc-resistant tube 38a made of polytetrafluoroethylene or the like.

Furthermore, a protrusion 39 is formed on the inner periphery of the tip of the contactor 36 to move toward and away from the fixed electrode 29 on the power source side, and an arc-proof metal 37a is provided at the tip.
A regulating ring 37b is fitted to the inner circumferential surface of the tip end of each contactor 36, and the contactors 37 facing each other are
The distance between 6 stations is now regulated.

The support cylinder 31, the contact 32 and the contact 36
A movable electrode section 30 is configured.

The support member 40 that is fitted around the outer periphery of the support cylinder 31 is made of insulating, gas-resistant, fiber-reinforced plastic and has a bottomed cylindrical shape, and is formed from the center toward the proximal end. Mounting hole 40a on the bottom
The support cylinder 31 is inserted through the support member 40 and a tightening bolt 41 is screwed into the support member 40 from the outer periphery of the support member 40, thereby fixing it integrally with the support cylinder 31.

A gas insertion hole 40b is provided at the bottom of the support member 40.
is transparent. Further, an orifice cone 42 made of synthetic resin having excellent arc resistance and insulation is screwed onto the inner periphery of the tip of the support member 40, and a nozzle 42a provided at the tip is connected to the fixed electrode 29. Formed to be insertable. Note that the orifice cone 42 is prevented from rotating by a set screw 42b screwed into the outer periphery of the support member 40. A pair of interlocking grooves 43 are formed in corresponding side portions of the support member 40 .

A circumferential mounting groove 44 is recessed in the outer periphery of the base end portion of the support member 40 . One end of a bellows 45 is fitted into the mounting groove 44, and a mounting ring 46 is further fitted around the outer periphery of the bellows 45, thereby airtightly mounting the bellows 45 thereon. An inner flange 45a is formed at the other end of the bellows 45;
is the inner end surface of the load side bushing 4 and the presser metal fitting 2.
Gap regulating ring 2 is inserted in the gap between 6 and 6.
It is slidably inserted into the outer periphery of 8.

The bellows 45 is made of synthetic rubber that is resistant to decomposition gas of arc-extinguishing gas.

Note that A is a pressure chamber surrounded by the bellows 45 and the support member 40.

As shown in FIG. 2, a drive shaft 48 is rotatably supported in the switch case 1 at a position below the fixed electrode 23 so as to extend over each phase, and a mechanism part provided outside the switch case 1 is provided. It can be operated using an automatic operation mechanism (not shown) inside the case 50 and an operation handle 51 provided on the mechanism case 50 (see FIG. 1). A swinging arm 49 having a U-shaped arm portion 49a at its tip is bolted to the drive shaft 48 for each phase, and a linking protrusion 49b provided on the inner surface of the arm portion 49a is connected to the linking groove 43. It is attached to allow some movement.

The operation of the switch configured as described above will be explained.

FIG. 2 shows an open state, and when the drive shaft 48 is rotated in the closing direction by external operation, the swing arm 4
9 is also rotated in the same direction, thereby supporting member 4
0, the movable electrode section 30, bellows 45, and orifice cone 42 are also moved in the charging direction. As a result, the contact 36 of the movable electrode section 30 is connected to the fixed electrode 2.
9, and the bellows 45, which is in a contracted state as shown in FIG. 2, is expanded as it moves in the closing direction. Then, since the internal pressure in the pressure chamber A decreases, the gas in the switch case 1 is sucked into the bellows 45 through the nozzle 42a and the gas communication hole 40a. At this time, the input is completed.

Next, when opening the circuit, the swing arm 49 is rotated in the opening direction via the drive shaft 48 by external operation from the closed state shown by the chain line in FIG.
a support member 39 and a movable electrode section 30 linked to the
Bellows 45 is moved in the opening direction. and,
When the contact 36 of the movable electrode section 30 separates from the fixed electrode 29, an arc is generated between the contact 36 and the tip of the fixed electrode 29. At this time, when the bellows 45 is contracted as shown by the solid line in FIG. 2 and the internal pressure within the pressure chamber A increases, the gas within the bellows 45 will not leak to the outside and will flow through the gas communication hole 40b of the support member 40 and the orifice cone 40. nozzle 42a
It is ejected to the outside through the contactor 36 and the fixed electrode 29, and is sprayed with force against the arc generated between the tips of the fixed electrode 29.

Therefore, the arc that occurs when the circuit is opened is the bellows 4.
The arc is elongated by the gas ejected from inside 5, and is finally blown away, effectively extinguishing the arc.

In this embodiment, fixed electrodes 23 arranged oppositely,
29 are arranged with their centers shifted, the contacts 32 and 36 of the movable electrode section 30 are connected to the support member 40.
Since the contactor 36 is rotatably attached to the fixed electrode 29, when the contactor 36 comes into contact with the fixed electrode 29, the contactor 36 tilts and is smoothly inserted. Furthermore, even if the contact 36 on the distal end side is sufficiently inserted into the fixed electrode 29 and the support cylinder 31 is tilted, the contact 32 on the base end side follows it, so that the contact 32 and the fixed electrode 23 are sufficient contact is ensured. or,
After that, even if the electrode section 30 is moved open, the movable electrode section 30 similarly moves smoothly.

This invention is not limited to the above-mentioned embodiment, and for example, although it is embodied in a gas switch in the embodiment described above, it may be embodied in other sealed type switches instead.

Effects of the invention As detailed above, with this invention, the bushings can be firmly pressed and fixed to the case over the entire circumference of each bushing. There are fewer tightening members such as mounting bolts and mounting parts for the bushing cover provided on the switch case, and the bushing cover for fixing the bushings of each phase is common to each phase. The number of parts is definitely reduced compared to conventional switches. Further, since the bushing cover is formed from cover members having the same shape, it is possible to use common parts.

Furthermore, since the present invention arranges a pair of cover members facing each other, the installation process is simple, in which the mounting recess is arranged from the side to correspond to the mounting flange of the three-phase bushing. There is no need to insert it from the axial direction of the bushing, so there is no risk of damaging the bushing.

Furthermore, the number of man-hours required for manufacturing the switch can be reduced.

[Brief explanation of the drawing]

Figure 1 is a side view of a switch embodying this idea, Figure 2 is a cross-sectional view of the switch, Figure 3 is a cutaway sectional view of the load-side bushing and movable electrode, and Figure 4 is the bushing cover. FIG. 1... Switch case, 2... Mounting member, 3...
Power supply side bushing, 3a... flange, 4... load side bushing, 4a... flange, 5... mounting bolt, 6... cover member, 6a... mounting recess,
6b... Projection piece, 6c... Projection piece, 6d... Bolt insertion hole, 6e... Bolt insertion hole, C... Bushing cover.

Claims (1)

[Scope of Claim for Utility Model Registration] A bushing in which a bushing is protruded outward from a switch case for each phase, and the mounting flange of each bushing is clamped and fixed between a common bushing cover for each phase and a wall surface of the switch case. In the mounting structure, the bushing cover C common to each phase is composed of a pair of cover members 6 of the same shape disposed from opposite sides to the mounting flange of the bushing of each phase, and the pressing of the cover member 6 is The plate portion 6g has a mounting recess 6 corresponding to the outer peripheral surface of the bushing of each phase.
a is formed, and a pressing plate portion 6g of one of the opposing cover members 6 is formed near one end of the pressing plate portion 6g.
The protruding piece 6b overlaps with the mounting recess 6a near the other end and the mounting recess 6a in the center.
A bushing mounting structure characterized in that a protruding piece 6c that overlaps one of the opposing cover members 6 extends between them.