JPH055633Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to the improvement of a high-voltage cutout with a built-in arrester used for primary side protection of pole-mounted transformers in lightning-struck areas. This invention relates to a structure devised to prevent fragments of the discharge gap device from being scattered outside the storage section even if the discharge gap device is damaged due to flow.

[Problems with conventional technology]

A voltage non-linear resistance element and a discharge gap device connected in series to the element are housed in a housing section formed of a through hole in the main body insulator to form an arrester section, and the above-mentioned discharge gap device (more precisely, the gap device It has already been proposed that an insulating spacer (insulating spacer) is integrally joined to the storage part using a low-melting glass frit.

By the way, in the above-mentioned bonding structure using glass frit, since the low melting point glass frit is heated and bonded during the bonding, stress remains in the insulating spacer, the main body insulator, and even the solidified glass frit, which have different coefficients of thermal expansion, during cooling, resulting in cracks. It may cause sharpness or sharpness. Therefore, as a countermeasure to this problem, only a part of the outer circumferential surface of the insulating spacer is joined to the inner circumferential surface of the storage portion. In other words, the filling amount (amount used) of low melting point glass frit is minimized.

However, with the above bonding structure, in the unlikely event that an external circuit (flash short) occurs in the voltage nonlinear resistance element and a follow-on arc flows in the gap of the discharge gap device, the arc heat will cause insulation. There was a risk that the spacer would break, and the broken pieces would fly out of the housing and collide with the lid insulator, damaging the insulator.

[Means to solve the problem]

The present invention is intended to solve the above-mentioned problems.The main body insulator is provided with a storage section consisting of a through hole, this storage section is divided into upper and lower sections, and the upper storage section of the above storage section has a voltage A non-linear resistance element is housed, and a discharge gap device is housed in the lower gap housing, and an annular groove is formed on the inner peripheral surface of the lower open end of the lower gap housing. An inverted dish-shaped shield is interposed between the annular groove and the discharge gap device, and a slot is formed in the peripheral wall of the shield to give the peripheral wall elasticity inward and outward. This high-pressure cutout with a built-in arrester is characterized in that the lower end of the peripheral wall portion is fitted and locked in an annular groove formed in the gap storage portion.

〔Example〕

Embodiments of the present invention will be described below in Figures 1 to 4.
This will be explained in detail based on the drawings.

1 shows a high-voltage cutout with a built-in arrester, in which an upper arc extinguishing device 3 is fixedly installed in the upper concave cutout 2a of the main insulator 2 made of ordinary porcelain or alumina-containing porcelain, and a lower arc extinguisher 3 is fixed in the lower concave cutout 2b. An arc extinguishing device 4 is fixedly installed. The upper and lower arc extinguishing devices 3 and 4 have slot-shaped upper and lower arc extinguishing chambers 5 and 6, clip-shaped upper and lower fixed contacts 7 and 8, and wire connection terminals 9 and 10.
The arc extinguishing devices 3, 4 are made up of upper and lower conductive fittings 11, 12 that connect the fixed contacts, and upper and lower fixing fittings 13, 14 that are integral with the fixed contacts.
4 is formed on the upper inner surface of the main body insulator 2.
c, 2d, and is fixed with the adhesive 15.

In addition, in the above case, the lower arc extinguishing chamber 6 is
4 as well as the extension part 6a of the arc extinguishing chamber are inserted into the mounting hole 2n and fixed with adhesive 16. Reference numeral 2e denotes a hollow housing section consisting of a through hole formed between the upper recessed notch 2a and the lower recessed notch 2b, and the same section is connected to the arrester storage section 2g upwardly by the inner step 2f. Further, a discharge gap device storage section 2h is formed in the lower part, and the arrester storage section 2g is formed with an upper end 2j of its peripheral wall projecting further upward from the upper surface 2k of the main body insulator. 17 is a donut-shaped zinc oxide (ZnO) element with voltage non-linearity stored in the arrester housing 2g, and 18 is a rubber shock-absorbing member such as EPR or EPT that is integrally attached to the outer peripheral surface of the zinc oxide element. The unevenness 18a is formed over the entire member. Reference numeral 19 denotes a contact auxiliary fitting that comes into close contact with the upper end surface 17a of the element 17; 20 refers to a cap fitting that is airtightly crimped to the open end of the arrester housing via an O-ring 21; and 22 is fixed to the center of the outer surface of the cap fitting. 23 and 24 are coil springs and flexible conductors interposed between the contact auxiliary fitting 19 and the cap fitting 20, and 25 is bonded to the upper end surface 17a of the element so as to close the upper side of the through hole 17b. A closing plate 26 is a filler made of silicone resin or the like that is injected densely into the gap in the arrester storage portion 2g, and 27 is an auxiliary contact plate that is in close contact with the lower end surface 17c of the element. The above discharge gap device storage section 2h
A tapered joint portion 2m that expands toward the insertion side (downward side) is formed on the lower side surface of the inner step portion 2f formed in the inner step portion 2f.

Next, 28 is a discharge gap device, which consists of an insulating spacer 29, a charging side discharge electrode 30, and a ground side discharge electrode 31. Above insulation spacer 2
Reference numeral 9 is made of ordinary porcelain, alumina porcelain, or titanium porcelain and is formed into a roughly bottle-shaped cylinder, and the outer peripheral surface 29a has a tapered joint 29b located approximately in the center and narrowing at the insertion end side. is formed to protrude laterally. Further, the charging side discharge electrode 30 consists of a discharge part 30a, a cap part 30b, and a metal communication tube 30c attached to the cap.The discharge part 30a is made of stainless steel, copper tan, etc., and the cap part 30b is It is made of a sealing metal such as Kovar, and the communication pipe 30c is made of stainless steel. The above-mentioned discharge part 30a has its threaded part 30
After being screwed from the inside into a screw hole 30b ₁ provided at the center of the cap part 30b ₁ so that the part a protrudes to the outside of the cap part 30b, the cap part 30b is integrally (airtightly) brazed. Further, the communication pipe 30c is inserted from the outside into the small hole 30b ₂ adjacent to the screw hole 30b ₁ and then brazed in the same manner. 4
8 indicates a nut for connection.

The earth side discharge electrode 31 is composed of a discharge portion 31a and a cap portion 31b. The discharge portion 31a is screwed into a screw hole _31b1 of the cap portion _31b with its screw portion 31a1 facing outward, and then brazed together.
The partition wall 49a is a connecting pipe for electrically connecting the above and the above, and a desiccant 50 is accommodated above the partition wall 49a.

In addition, the cap portion 30b of the charging side discharge electrode 30
is provided so as to close the opening 29c on the large diameter side, and the insulating spacer is provided with an inward annular protrusion _30b3 on the same side as the tip extending along the side circumferential surface of the insulating spacer. A low melting point glass frit 32 is injected into the gap between it and the peripheral surface, and heat treated to seal airtightly.

Further, the cap portion 31b of the earth side discharge electrode is provided so as to close the small diameter opening 29d, and the annular protrusion 31b ₅ of the cap portion 31b.
Once in contact with the side peripheral surface 29a' of the insulating spacer 29, its extension and the copper peripheral surface 2 of the insulating spacer 29
A low melting point glass frit 32 is injected into the gap between it and 9a', and is heat treated to seal hermetically.

Note that the cap portions 30b and 31b of the discharge electrodes are designed to close the openings 29c and 29d at both ends of the insulating spacer 29, respectively, in the event that a follow-on arc flows into the discharge gap G. Flat portions 30b ₅ and 31b ₄ are provided to prevent the cap from being destroyed (melted) due to heat.
The thickness of the side circumferential surfaces 30b ₄ and 31b ₃ is thicker than that of the side peripheral surfaces 30b 4 and 31b 3 . The low melting point glass frit 32 used for the above sealing is a crystalline sealing glass (for example, manufactured by Iwaki Glass, product number 7574, sealing temperature 750
℃) is used, but apart from this, the melting temperature is
It may be hermetically sealed using silver solder at about 1000°C.

However, in this case, on the insulating spacer 29,
Use one with a metallized portion formed on the lower outer peripheral surface.

The charging side discharge electrode 30 and the ground side discharge electrode 31 with the openings at both ends of the insulating spacer 29 sealed in this way are connected to the respective discharge portions 30 of both electrodes.
a and 31a face each other within the insulating spacer 29 to form a predetermined discharge gap G.

In addition, when sealing, the above discharge gap device
In order to maintain the inside of the device at atmospheric pressure (1 atm) at room temperature, the cap part 30 of the charging side discharge electrode 30
A communication pipe 30c attached to b that communicates the inside and outside of the device is crimped in the final assembly stage of the discharge gap device 28, and further sealed by TIG welding. That is, the above-mentioned sealing conditions set the commercial frequency discharge starting voltage to 13.9 kv or more and the lightning impulse discharge starting voltage to 33 kv or less.

Next, the discharge gap device 28 assembled in a sealed state as described above is inserted into the gap storage section 2h of the main body insulator 2.
We will explain the case of incorporating it into . First, the above-mentioned discharge gap device 2 is sealed and assembled in a hermetically sealed state.
Regarding No. 8, a sealing material 33 made of an inorganic material such as glass wool is fitted from the front onto the outer circumferential surface of the small diameter portion of the insulating spacer 29, that is, the outer circumferential surface 29a at a position adjacent to the joint portion 29b. Then, it is installed with the earth-side discharge electrode facing down (inner side) with respect to the gap housing portion 2h of the main body insulator 2 in which nothing is installed. In this case, the gap storage portion 2h has a reverse tapered joint portion 2m whose inner circumferential surface narrows inward as it goes downwards (backwards).
Since the joint 29b of the insulating spacer 29 is tightly joined to the joint 2m, the discharge gap device is supported and fixed.

In addition, when bringing both the joint parts 2m, 29b into close contact as described above, first
Slurry-like low melting point glass frit 3 for 9b
It is desirable to apply 4. Then, in this tightly joined state, the main body insulator 2 is placed in a heating furnace with the gap device storage portion 2g facing downward, heated for a predetermined period of time, and then slowly cooled to room temperature to tightly join both joined parts together.

Low melting point glass frit 3 used in the above
4 is an amorphous sealing glass (for example, Iwaki Glass Co., Ltd. product name: T191, sealing temperature 430°C) whose sealing temperature is lower than that of the low melting point glass frit 32 used when sealing the discharge electrode. Are suitable.

Note that the sealing material 33 described above is temporarily removed after the heat treatment is completed, but there is no particular need to remove it. The housed discharge gap device 28 has its charging side discharge electrode 30 connected to the lower fixed contact 8 via the connection plate 35.
The ground side discharge electrode 31 is connected to the auxiliary contact plate 27 on the lower end surface of the element. 51 is an insulating member made of synthetic resin such as FRP, polyacetal, polyethylene, nylon, ABS, etc., or hard rubber, which is fitted into the annular groove 2q formed on the inner circumferential surface of the open end 2p of the discharge gap device housing portion 2h. It is an inverted dish-shaped shield and is attached to surround the outside (lower side) of the discharge gap device 28. As shown in FIG. 3, the shield has a small hole 51a made of a potbelly hole formed in the center thereof, and a slot 51c is formed in the peripheral wall portion 51b for imparting elasticity to the peripheral wall portion. 36 is a gap device 28 and a shield 51
After installation, a silicone resin-based filler with insulating properties is injected into the housing to completely cover the outer surfaces of the housing.

Next, 37 is a lid insulator which is pivotally attached to the main insulator 2 by a pin 38 so as to be freely openable and closable, and which is detachably attached to the inner surface by a fitting fitting 39 of an elastic member and an engaging piece 40. It has a fuse tube 41 attached thereto.

The fuse tube 41 has a blade-shaped upper movable contact 42 projecting upward at its upper part, and a lower movable contact 43 at its lower part, and further electrically connects these two movable contacts 42 and 43. A fuse 44 is provided. In addition, when the lid insulator 37 is closed, the above-mentioned movable contacts 42 and 43 are in contact with the clip-shaped fixed contacts 7 and 8 on the main body insulator 2 side.
The two fixed contacts 7 and 8 are brought into pinch contact with each other, so that the fuse 44 electrically closes both the fixed contacts 7 and 8. Reference numeral 45 denotes a support metal fitting attached to the upper surface 2k of the main insulator 2, and the metal fitting is screwed to mounting bolts 47 fixed with an adhesive 46 such as cement on the upper and lower sides of the upper surface 2k with the arrester storage portion 2g in between. has been done.

In the high voltage cutout having the above configuration, insulation is ensured in the discharge gap G of the discharge gap device in normal times, so the above electric wire connection terminal 9-
Upper fixed contact 7 - Upper movable contact 42 - Fuse 4
4-lower movable contact 43-lower fixed contact 8-lower wire connection terminal 10-high-voltage underline wire-power is applied through the path of the primary terminal of the pole transformer. In the above, the next time a lightning surge enters, a discharge occurs in the discharge gap G due to the same surge, so the intruding surge is caused by the upper wire connection terminal 9 - upper fixed contact 7 - upper movable contact 42 - fuse 44 - lower movable Contact 43 - Lower fixed contact 8 - Connection plate 35 - Charging side discharge electrode 30 - Discharge gap G - Earth side discharge electrode 31 - Auxiliary contact plate 27 - Zinc oxide (ZnO) element 17 - Coil spring 23/movable conductor 24 - Cap metal fittings 20 - Earth side terminal 22 - The discharge is discharged to the ground via a contact wire connected to the terminal.

Furthermore, in the above, if an external circuit occurs in the through hole 17b of the zinc oxide element 17 due to excessive lightning surge, the pressure inside the hole will increase, but this pressure will cause the closing plate to rise. 25,
Since the cap fittings 20 are removed one after another, the same pressure is quickly released to the outside, and explosion of the arrester (specifically, the housing portion of the main body insulator) can be prevented. and
The AC (commercial frequency) follow-on current is cut off in about 0.5 cycles by a fuse interposed in the discharge path, that is, a cut-out fuse 44, but in this case, it goes without saying that the discharge gap G of the discharge gap device 28 is also interrupted. Since a follow-up arc flows until the above-mentioned interruption is completed, there is a risk that the insulating spacer 29 may break due to the heat of the arc, but even if the spacer breaks, the shield 51 will prevent the insulating spacer 29 from breaking. This prevents fragments from scattering.

[Effect of idea]

The present invention has the above-mentioned configuration, and even if the insulating (gap) spacer is broken by the following arc, the insulator fitted on the inner peripheral surface of the open end of the housing section of the main insulator Because fragments, etc. are prevented from flying out by the sexual shield,
Damage caused by collision of the lid insulator due to flying fragments is reliably prevented.

In addition, since the above-mentioned insulating shield has slots formed to give it elasticity, it can be easily installed by simply pushing it into the annular groove formed on the inner peripheral surface of the open end. can.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a longitudinal cross-sectional view of a high-pressure cutout, and FIG. 2 is a longitudinal cross-sectional view showing the main parts, showing the state before the shield etc. are assembled. Figure 3 shows the shield, in which a shows a front view, b shows a longitudinal sectional view, and c shows a side view.
The figure shows an insulating spacer, and shows a side view with the right half in section. 2...Body insulator, 2h...Discharge gap device housing section, 2p...Open end, 2q...Annular groove, 28...
...discharge gap, 51...shielding body, 51b...peripheral wall portion, 51c...slit.

Claims (1)

[Scope of utility model registration request] A storage section consisting of a through hole is provided in the main body insulator, and this storage section is divided into upper and lower sections, and a voltage nonlinear resistance element is stored in the upper storage section of the storage section, and a gap storage section is provided in the lower part. In each case, an annular groove is formed on the inner circumferential surface of the lower open end of the lower gap storage portion, and an inverted dish-shaped shield is provided between the annular groove and the discharge gap device. an annular groove interposed between the body and the circumferential wall of the shield to give elasticity inward and outward by forming a slit in the circumferential wall of the shield, and forming a lower end of the circumferential wall in the gap storage portion; A high-pressure cutout with a built-in arrester, which features a built-in arrester that is fitted and locked.