JPS6118607Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a power fuse particularly for outdoor use, and maintains airtightness by creating a double seal with an O-ring member or the like between the insulating outer cylinder of the fuse and the electrodes at both ends. In addition, in the unlikely event that a manufacturing error or local cause of the power fuse does not allow the fuse to break or break properly, the fuse itself or the fuse holder may be damaged, resulting in a major accident. The purpose is to prevent

Until now, this type of power fuse was mainly used indoors or in cubicles for short-circuit protection, but as the performance of fuses improved, for example, box-shaped cut-out switches and cylindrical cut-out switches for protecting transformers were used. It is now possible to incorporate into
Development for 20KV class extra-high pressure applications is also progressing.

Unlike normal discharge type fuses, this type of power fuse is a sealed type, so it is safe because it does not emit arc to the outside, but on the other hand, if some abnormal situation occurs, the pressure inside the fuse will become abnormally high. There is a risk that the insulating outer cylinder will not be able to withstand the strength and break down.

Arc-extinguishing sand is sealed inside the power fuse, which contributes to arc-extinguishing. However, if the sealing condition is poor and moisture, etc. enters the interior, the performance of the arc-extinguishing sand will deteriorate, and the insulation will not be able to recover and it will soon break. It becomes impossible and causes destruction. Furthermore, although porcelain or crystallized glass porcelain has conventionally been used for the insulating outer cylinder of this type of power fuse, it must be able to withstand shocks and the like sufficiently in order to be used outdoors.

Therefore, the power fuse of the present invention uses glass fiber reinforced plastic as the insulating outer cylinder.
A groove is provided on the outer periphery near both ends of this outer cylinder, an O-ring member, etc. is fitted into the outer cylinder, and then the electrode is fixed to the outer cylinder with adhesive to create a double airtight structure with the adhesive and the O-ring member, and in case of a fuse. In order to prevent damage to the equipment even if the cap discharge cannot be broken or disconnected, a weak part is provided at the bottom of one of the cap discharge electrodes, and the gas pressure is used to pierce that part and release the pressure to the outside. This is a power fuse characterized by its pressure release being directional.

Below, the structure of the present invention will be explained in detail based on the drawings. In the drawing, 1 is an insulating outer cylinder made of glass fiber reinforced plastic (FRP), and a cap-shaped electrode 2 is attached to one open end with a screw 30. The fitting part A is fixed to the insulating outer cylinder 1 from the electrode 2.
30 parts of the screw are filled with an adhesive. The other end open part is fixed to the cap-shaped electrode 3 with a fitting part B using a screw 31, and the fitting part B is also fixed to the fitting part A.
Similarly, the electrode 3 is filled with adhesive, and a skirt portion 4 is integrally formed in the direction opposite to the fitting portion B through an intermediate wall 4a serving as a bottom portion, and the skirt portion 4 is formed on the outer periphery of the skirt portion 4. is provided with a threaded portion 4b.
Further, a cylindrical link adapter 12 screwed onto the threaded portion 4b of the skirt portion 4 is disposed so as to cover the cylindrical portion 3a of the electrode 3. Same link adapter 12
is provided with a bottom wall 13 projecting on the inner side near its lower end for reinforcement and for preventing the insulating core 7 and cylinder body 9 from popping out in the event of an abnormality, and furthermore, the bottom wall 13 extends downward from the periphery of the bottom wall 13. A skirt portion 12a similar to that of the electrode 3 is formed, and an end portion of the skirt portion is engaged with the bottom wall 13. The electrode 3 and link adapter 12 are combined to form a lower electrode 6. Therefore, the link adapter 12 can be freely selected and used for the lower electrode 6 according to the installation of the device or the like.

The intermediate wall 4a of the electrode 3 is formed in an annular shape with a thickness thinner than other parts except for the center part, and includes a pressure relief part 14 whose strength is weaker than that of the insulating outer cylinder 1 and the like. and,
A similar annular cut groove 14a is provided in the center of the lower surface of the pressure relief part 14, so that when the fuse cannot be disconnected, a portion of the pressure relief part 14 located outside the cut groove 14A is pierced. . Grooves are cut on the outer periphery near both ends of the insulating outer cylinder 1, and O-ring members 5 are fitted into the grooves, respectively, and the electrodes are adhesively fixed to the outer cylinder. In addition, the open inner circumferential edges 2a, 3b of the electrodes 2, 3 are formed obliquely to facilitate insertion of the insulating outer cylinder 1, and the open inner circumferential edges 2a, 3b and the insulating outer cylinder 1
The gaps C and D between the outer peripheral surfaces are filled with an adhesive 36. Therefore, there are screws 3 between the electrode 3 and the insulating outer cylinder 1 and between the upper electrode 2 and the insulating outer cylinder 1, respectively.
0, 31 A double airtight structure is created by the adhesive filled in the bonding area and the gaps C and D and the O-ring member 5, so even if some moisture tries to enter from the adhesive due to some action, the O-ring member 5 will prevent the water from entering. It does not penetrate into the interior of the fuse, thereby preventing deterioration of the arc-extinguishing sand 17 and the like. Also, both the upper and lower electrodes 2 and 3
is fixed to the outer cylinder 1 with sufficient strength by the action of the screw 30 attachment part.

A pair of upper and lower intermediate electrodes 8 are fixed to both ends of the insulating core 7 located approximately at the center of the insulating outer cylinder 1, and are electrically connected by a fuse element F.
The upper intermediate electrode 3 whose skirt portion is fixed to the insulating core 7 is press-fixed to the upper electrode 2 via a fixing member 34 by a plug 33 screwed into the upper electrode 2. 35 is the fixing member 34 and the plug 3
It is an O-ring member fitted between the plug body 33 and seals the upper end of the insulating outer cylinder 1 in cooperation with the adhesion of the threaded portion of the plug body 33.

A cylindrical body 9 that penetrates the center of the bottom wall 13 of the link adapter 12 and is adhesively fixed to the lower surface of the intermediate wall 4a of the electrode 3 is connected to a resistance wire 11 inserted into the center hole of the insulating core 7. This is a case in which a display piece 16 is installed inside. An O-ring member 32 is fitted between the cylindrical body 9 and the intermediate wall 4a, and the bonding and double airtight structure between the two 9 and 4a is achieved.

Further, as shown in FIGS. 1 and 2, a plurality of quarter-arc-shaped pressure relief portions 15 are transparently provided in the bottom wall 13 of the link adapter 12 in correspondence with the pressure relief portions 14.

Therefore, a thin pressure relief part 14 is generated inside the fuse.
The abnormal gas pressure that has broken the link adapter 12 is released through the pressure relief hole 15 of the link adapter 12, and the skirt portion 12
It is guided in a certain direction to the lower opening of the link adapter 12 at point a. Furthermore, even if the insulating core 7 and the cylindrical body 9 were to fly due to this abnormal gas pressure, the bottom wall 13 protruding from the link adapter 12 would prevent them from flying downward.

FIG. 3 shows an embodiment in which the fuse of the present invention is applied to a cylindrical cut-out switch, and the fuse of the present invention is housed inside a main body insulator 20 having a hollow interior. A lower fixed electrode 21 is provided at the lower part of the main body insulator 20 to contact and fix the link adapter 12, which is a part of the lower electrode 6 of the fuse.

In the figure, numeral 22 is an upper lead wire, 23 is a lower lead wire, and 24 is a sealing plug that also serves as an indicator.

As detailed above, the power fuse of the present invention adopts a double airtight structure between the insulating outer cylinder 1 and the upper and lower electrodes 2 and 3, so that it can be used outdoors under difficult conditions. While this prevents moisture from entering the interior of this type of power fuse even if the fuse is exposed to water, the deterioration of the arc-breaking performance due to deterioration of the arc-extinguishing sand, which is the lifeblood of this type of power fuse, can be prevented. Therefore, even if an unbreakable condition occurs, the abnormal gas pressure will be alleviated by the pressure relief operation by the pressure relief section, and the fuse itself will not be destroyed.
In addition, the bottom wall 15 provided on the link adapter 12 prevents the insulating core etc. from popping out.
It combines three layers of safety and prevents major accidents from spilling over into accidents resulting in injury or death. It has excellent characteristics.

When the switch is attached to a cylindrical cut-out switch as shown in FIG. 3, the gas pressure that pierces through the electrode part of the fuse and is released from the pressure release hole 15 is transferred from the bottom wall 13 of the link adapter 12 to the cylindrical part 12b. Since the insulator is forced to be emitted only in a downward direction by the skirt portion 12a extending in the opposite direction, it is used in a structure where the lower end of the main body is open, such as a cylindrical cut-out switch. If this happens, it will be smoothly released outside the vessel. Furthermore, as shown in FIG. 3, the inner surface of the lower part of the main body insulator 20 and the lower fixed electrode 21 provided therein are not directly affected by the gas pressure due to the link adapter 12, and the fuse of the present invention is installed internally. This will not cause damage to equipment such as the cylindrical cut-out switch.

If it is used for extra-high voltage, the equipment itself will be considerably larger and the danger will be greater. Therefore, fuses like the power fuse of this invention, which emphasize performance improvement and safety without sacrificing any of the advantages of conventional power fuses, are This is an excellent idea that can greatly contribute to industry.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; Fig. 1 is a partially cutaway front view of a power fuse, Fig. 2 is a bottom view of the same, and Fig. 3 is an application of the power fuse of the present invention to a cylindrical cut-out switch. It is a partially sectional view. Insulating outer cylinder...1, Electrode...2, 3, O-ring member...5, Link adapter...12, Pressure relief part...
14, Pressure relief hole...15, Arc-extinguishing sand...17.

Claims (1)

[Claims for Utility Model Registration] 1. In a power fuse containing an arc-extinguishing agent such as arc-extinguishing sand 17, an insulating outer cylinder 1 made of glass fiber reinforced plastics is provided with O-rings 5 at both ends to form a cap-like structure. Screw the electrodes 2 and 3 of
The fitting portions A, B and the electrode open inner circumferential edges 2a, 3 are fixed together.
The gaps C and D between the outer circumferential surface of the insulating outer cylinder 1 and the outer peripheral surface of the insulating outer cylinder 1 are filled with an adhesive, and sealed by double sealing means using the adhesive and the O-ring member 5,
A pressure relief part 14 is provided at a part of the bottom of the one electrode 3, and the pressure release part 14 is made thinner than the other part so as to be able to burst when an abnormal gas pressure rises inside the fuse. Cylindrical part 1 that covers
2b, a bottom wall 13 having a pressure relief hole 15 located corresponding to the pressure relief part 14, and a skirt part 12a extending from the bottom wall 13 in a direction opposite to the cylindrical part 12b. link adapter 12
A power fuse characterized in that the fuse is formed to be removably fitted. 2. The power fuse according to claim 1 of the utility model registration, in which the pressure release part 14 is formed in an annular shape.