JPH0418194Y2 - - Google Patents

Description

[Detailed description of the invention] A-1 Field of industrial application The present invention relates to an improvement of a cylindrical cutout with a discharge electrode used as a primary side protection device of a pole transformer in a high-voltage distribution line. The present invention relates to a discharge part structure that prevents discharge and at the same time stabilizes discharge characteristics.

A-2 Prior Art A cylindrical cutout with a built-in current-limiting element has already been used as a primary side protection device for a pole-mounted transformer on high-voltage distribution lines in areas affected by lightning.

This cutout has a current limiting element with excellent voltage non-linearity built into the cutout body, and one terminal of the built-in element is connected to the lower fixed electrode of the cutout, and the other terminal is also attached to the same terminal. A predetermined discharge gap is formed and the grounding side discharge electrode is connected to the mounting bracket through the charging side discharge electrode.
Lightning surges that try to enter the pole transformer via the distribution line are safely released to the ground through the current limiting element built into the cutout body, thereby limiting the voltage to a low level and insulating the pole transformer. I try to give from destruction.

E-3 Problems to be Solved by the Present Invention By the way, in the cut-out with a discharge electrode of the above-mentioned conventional configuration, the charging-side discharge electrode located inside the cut-out body is connected to the insulating lower cover fixed to the lower end opening of the cut-out body. It faces a ground-side discharge electrode through a discharge hole, and both discharge electrodes form a discharge gap. That is, the lower cover is provided with a discharge hole located on the side surface and passing through the inside and outside of the cover.

Therefore, if a worker accidentally inserts the binding wire into the same hole while working, the binding wire may come into contact with the charging-side discharge electrode located at the back of the hole, especially when the electrode is in a charging state. There was a risk of electric shock.

In addition, since the above-mentioned discharge hole has a through-hole shape, if rainwater enters the hole during rain, the dielectric rainwater will stagnate inside the hole, interfering with the discharge operation and making the discharge characteristics extremely unstable. There were also some problems.

B. Structure of the device B-1 Means for solving the problem The present invention is intended to solve the problem. Built-in current limiting element 7
One end is connected to the lower fixed electrode 11 of the cutout, and the charging side discharge electrode 13 at the other end of the element is fixed to the lower end opening 1a of the cutout body to the ground side discharge electrode 18 that connects to the mounting bracket 3. In the case where the insulating lower cover 5 is opposed to each other through the discharge hole to form a discharge gap, the lower cover 5 is formed with a mounting hole 5c, and the mounting hole 5c has a mounting hole 5c for connecting the cover to the lower cover 5. When fitted, an insulating bush 16 with a small discharge hole 16a passing through the inside and outside of the cover is fitted, and an inner end 16c of the small discharge hole 16a located on the cutout body side of the fitted bush 16 is fitted. , the above-mentioned charging side discharge electrode 13 is brought into contact with the discharge part 13c of the electrode to be seen into the small discharge hole 16a, and the outer end side 16d of the small discharge hole 16a located on the cut-out main body side of the same bush. A lid-shaped lid is provided which closes the outer end of the hole and at the same time forms a discharge gap 1 facing the ground side discharge electrode 18 and also faces the charging side discharge electrode 13 to form a discharge auxiliary gap 2. A cylindrical cut-out discharge section with a discharge electrode characterized in that an intermediate electrode 17 is provided is proposed.

B. Function: An insulating bushing with a small discharge hole is fitted into the mounting hole of the lower cover. On the outer end side of the small discharge hole, there is a lid-shaped intermediate electrode that faces the charging side discharge electrode and the grounding side discharge electrode and forms a discharge auxiliary gap _g1 and a discharge gap _g2 , respectively. It is provided so as to close the outer end side of the small discharge hole.

Therefore, the intermediate electrode provided on the outer end side of the small discharge hole can prevent the binding wire or the like from being inserted into the hole by mistake, so that electric shock accidents can be prevented. Furthermore, rainwater, which is a dielectric material, is prevented from entering the hole and stagnation, thereby stabilizing the discharge characteristics.

C. Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 and 2.

Reference numeral 1 denotes a porcelain body, which is connected to a arm mounting bracket 3 via a support bracket 2 fastened to the center of the body. The support fitting 2 and the mounting fitting 3 are grounded via a grounded arm 4. Reference numeral 5 designates a lower cover made of synthetic resin such as polyethylene, which is fixed to the lower end opening 1a of the main body 1 with an adhesive, and a current limiting element unit 6 having a semicircular arc cross section is installed in the concave housing portion 5a. keeping. The current limiting element unit 6 is a current limiting element made of zinc oxide (ZnO) as a main component, to which a small amount of metal oxide is added, and which is fired at a high temperature and has excellent voltage nonlinearity and is stacked in two layers, upper and lower. Element 7 and
The upper terminal 8 connected to the upper end surface of the current limiting element, the lower terminal 9 connected to the lower end surface of the current limiting element 7, the outer circumferential surface of the current limiting element 7, and the connection parts 8a, 9a between the upper and lower terminals 8, 9. An insulating member 10 made of synthetic resin or rubber, which is integrally molded to cover the outer peripheral surfaces of both terminals except for
After being held on the lower cover 5 as described above, the upper terminal 8 is connected to the lower fixed electrode 11 on the cutout side by the connecting conductor plate 12, and the lower terminal 9 has its connecting portion 9a charged. A connecting portion 13a of the side discharge electrode 13 is provided in a screw-connected manner. Reference numerals 14 and 15 indicate connection screws.

Reference numeral 5c is a mounting hole of the lower cover formed on the side facing the mounting bracket 3, that is, the side surface 5b of the cover, and this mounting hole 5c has an electric discharge that passes through the inside and outside of the lower cover when it is fitted into the hole. An insulating bush 16 made of rubber or synthetic resin is fitted with a small hole 16a located approximately in the center.

The bush 16 is fitted by pushing the locking portion 16b on the flange against the outer surface 5e of the lower cover 5 from the outside of the mounting hole 5c.
In this case, the flange-shaped tip 13b of the charging side discharge electrode 13 comes into contact with the inner end 16c of the small discharge hole 16a located inside the main body so as to close the small hole 16a, and the pointed discharge part 13c is attached so as to look into the hole 16a.

Reference numeral 17 denotes a lid-shaped intermediate electrode made of a hard metal plate such as stainless steel, which is provided on the outer end side 16d of the small discharge hole 16a located outside the main body; is closed to prevent a binding wire or the like from being inserted into the hole, and a discharge auxiliary gear is placed opposite the discharge portion 13c of the charging side discharge electrode 13 located on the inner end side 16c of the small discharge hole 16a. g ₂ , and then attach the mounting bracket 3
It also faces a ground side discharge electrode 18, which will be described later, which is connected to the discharge gap _g1 .

Note that the above-mentioned intermediate electrode 17 has a small discharge hole 16a.
Intermediate electrode 1
7 first, and then insert the small discharge hole 16.
An insulating ring 19 having an inner diameter 19a larger than a is inserted, and the ring is glued and fixed to the same part.

In addition, 18 is the horizontal mounting portion 3 at the lower end of the mounting bracket 3.
This is a plate-shaped ground-side discharge electrode which is stacked on the lower surface side of a and tightened with a bolt 20 and a nut 21, and a discharge gap _g1 is formed with the discharging portion 18a at the tip facing the intermediate electrode 17. is forming.

Note that the ground side discharge electrode 18 is formed with a long hole 18b extending toward the intermediate electrode, and the bolt 20 and the guide protrusion 3a formed in the horizontal mounting portion 3c and projecting downward are formed in the long hole 18b. If the ground-side discharge electrode 18 is moved while the nut 21 screwed onto the bolt 20 is slightly loosened, the electrode slides horizontally (toward the intermediate electrode) and the discharge gap _g1 is adjusted to a predetermined gap length. It is now possible to adjust to 22 is an upper lead wire of the cutout, 23 is an upper fixed electrode made of a tube contact, 11 is the above-mentioned lower fixed electrode, 24 is an upper contact 25 of which contacts the upper fixed electrode 23, and a lower contact 26 of which is connected to the lower fixed electrode. This is a fuse tube held vertically within the cutout body 11 in contact with the electrodes 11, respectively, and a fuse 27 is attached thereto.

Reference numeral 28 denotes an arc extinguishing rod suspended within the upper fixed electrode 25, 29 an arc extinguishing tube forming a slit arc extinguishing section together with the arc extinguishing rod 28, and 30 an inner step within the main body. Synthetic resin buffer ring provided in 1b, 3
1 is a lower lead wire connected to the lower fixed electrode 11;
32 is an engagement piece 3 attached to the lower end opening 5d of the lower cover 5.
Reference numeral 3 indicates a seal plug made of synthetic resin such as polyethylene, which is removably inserted, and 34 indicates a string connecting the seal plug 32 and the lower cover 5.

In the above configuration, if lightning surge intrudes,
Discharge occurs in the discharge gap g ₁ and the discharge auxiliary gap g ₂ , and the surge is caused by the upper lead wire 22 - the upper fixed electrode 23 - the upper contact 25 - the fuse 27 - the lower contact 26 - the lower fixed electrode 11 - the connecting conductor plate 12 -
Upper terminal 8 - Current limiting element 7 - Lower terminal 9 - Charging side discharge electrode 13 - Discharge auxiliary gap g ₂ - Intermediate electrode 17
- Discharge gap g ₁ - Ground side discharge electrode 18 - Discharge occurs through the earth discharge path.

In this case, since the current limiting element 11 having excellent voltage non-linearity is interposed in the discharge path, only the lightning current flows to the ground and subsequent current is blocked.

However, at the same time, the voltage is also limited to a low level.

As a result, the cutout fuse is prevented from blowing, and the pole transformer is further protected from insulation breakdown.

C. Effects of the invention As described above, the present invention involves fitting an insulating bushing equipped with a small discharge hole penetrating the inside and outside of the lower cover into the mounting hole of the lower cover, and A charging-side discharge electrode is brought into contact with the inner end located inside the main body, and its discharge part is seen into the small discharge hole, and the same small electrode is placed on the outer end of the small discharge hole located outside the main body. A lid-like intermediate electrode is provided to close the hole, and the intermediate electrode thus provided forms a discharge gap g ₁ with the grounding side discharge electrode, and an auxiliary discharge gap g ₂ with the charging side discharge electrode. This prevents the binding wire from being accidentally inserted from the outside of the small discharge hole, thereby preventing electric shock accidents and further increasing safety for workers.

Additionally, as mentioned above, since there is an intermediate electrode between the charging side discharge electrode and the grounding side discharge electrode, this stabilizes the discharge characteristics and provides even more reliable protection against pole transformers, etc. becomes.

In addition, since the outer end of the discharge hole is closed with a lid-shaped intermediate electrode, rainwater, which is a dielectric material, does not soak into the discharge hole or stagnate, so rainwater does not accumulate when it rains. Since the discharge operation is not hindered, variations in the discharge starting voltage are thereby prevented, and the discharge characteristics are always stable.

[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 cylindrical cutout with a discharge electrode, and FIG.
The figure is an enlarged vertical cross-sectional view of the circle in FIG. 1. DESCRIPTION OF SYMBOLS 1...Main body, 1a...Lower end opening, 5...Lower cover, 5c...Mounting hole, 6...Current limiting element unit, 11...Lower fixed electrode, 13...Charging side discharge electrode, 13c... Discharge part, 16...Butsuyu, 1
6a...Small discharge hole, 17...Intermediate electrode, 18...
...Ground side discharge electrode, g ₁ ...Discharge gap, g ₂ ...
Discharge auxiliary gap.

Claims (1)

[Claims for Utility Model Registration] The main body 1 of the cut-out has a built-in current-limiting element 7 having voltage non-linearity, and the built-in current-limiting element 7
One end is connected to the lower fixed electrode 11 of the cutout, and the charging side discharge electrode 13 at the other end of the element is fixed to the lower end opening 1a of the cutout body to the ground side discharge electrode 18 that connects to the mounting bracket 3. In the case where the insulating lower cover 5 is opposed to each other through the discharge hole to form a discharge gap, the lower cover 5 is formed with a mounting hole 5c, and the mounting hole 5c has a mounting hole 5c for connecting the cover to the lower cover 5. When fitted, an insulating bush 16 with a small discharge hole 16a passing through the inside and outside of the cover is fitted, and an inner end 16c of the small discharge hole 16a located on the cutout body side of the fitted bush 16 is fitted. , the charging-side discharge electrode 13 is brought into contact with the electrode so that the discharge portion 13c of the electrode can be seen into the small discharge hole 16a, and the outer end side 16d of the small discharge hole 16a located outside the cut-out body of the same bush. A lid-shaped lid is provided which closes the outer end of the hole and simultaneously forms a discharge gap 1 facing the ground side discharge electrode 18 and further faces the discharge side discharge electrode 13 to form a discharge auxiliary gap 2. A cylindrical cut-out discharge section with a discharge electrode characterized in that an intermediate electrode 17 is provided.