JPH0441592Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to the improvement of insulator type arresters used in high-voltage distribution lines, and in particular to safely prevent abnormal voltages such as lightning surges propagating through insulated wires (distribution lines). This relates to the structure of an insulator-type arrester that has a release type fuse built into the insulator body to release the AC (commercial frequency) current to the ground and at the same time cut off the follow-on current of AC (commercial frequency).

[Prior art and its problems]

In high-voltage distribution lines, it has the function of supporting insulated wires in the same way as high-voltage pin insulators, and the function of an arrester to safely release abnormal high voltages such as lightning surges propagating through distribution lines to the ground. Insulator arresters have recently come into use.

As mentioned above, this insulator-type arrester is intended to be used in the same way as a high-voltage pin insulator, so it cannot be made particularly large in shape compared to a pin insulator. The voltage non-linear resistance element (ZNO element) built into the insulator is also limited in its shape (cross-sectional area and length), which inevitably reduces the discharge capacity of the resistance element and causes external circuits in the resistance element. (external flash fault) is more likely to occur, which causes an AC (commercial frequency) follow-on current to flow, and the generated arc can cause an explosion accident in the insulator.

(Means for Solving the Problems) The present invention is intended to solve the above problems, and includes forming a hollow storage section in the insulator body, and a voltage nonlinear resistance element in the storage section. The upper part of the insulator body is connected to one end of the above-mentioned resistance element, and a wire connection terminal is fixed to support the insulated wire and at the same time to make an electrical connection, and the lower part is connected to one end of the above-mentioned resistance element An insulator type arrester is connected to the end, and a base metal fitting for attaching the insulator body to a cross arm such as a utility pole is fixed, and the base metal fitting is provided with a mounting bolt and a nut provided on the same bolt, The housing part is formed into a through hole, a voltage non-linear resistance element is stored in the lower part of the housing part, and a discharge type fuse tube with both ends open is installed in the upper part of the housing part. A fuse wire with one end connected to the lower end surface of the resistance element and the other end connected to the wire connection terminal is stretched, and the wire connection terminal is connected to the fuse wire located in the upper opening of the fuse tube. , proposes an insulator type arrester characterized in that an arc discharge port is normally closed by a thin plate pressure relief cover.

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

Reference numeral 1 denotes an insulator body having double deep grooves 1a formed on the outer circumferential surface and a through-hole storage portion 1b formed in the center.The storage portion 1b is located on the upper side to form a fuse storage portion 1c. A resistive element housing portion 1d is formed at the lower side.

2 is a doughnut-shaped voltage nonlinear resistance element made of a zinc oxide (ZnO) element provided with a discharge hole 2a, and the element 2 is stored in the above-mentioned resistance element storage part 1d in a vertically stacked state of three layers. ing. 3 indicates an insulating member such as a rubber band.

Reference numeral 4 denotes a cap-shaped upper sealing plate made of a thin phosphor bronze plate, copper plate, stainless steel plate, etc., which is metallized on the upper step portion 1e of the resistance element housing portion 1d and further hermetically bonded with a wax material. 4 is in contact with the upper end surface 2a of the resistive element 2. Reference numeral 5 designates a lower sealing plate which is metallized and soldered to the inner circumferential surface 1g of the opening end 1f on the lower side of the resistive element housing portion 1d to form a hermetically sealed seal in the same manner as the upper sealing plate 4. A stretchable bending portion 5a is formed in a part of the plate. The lower sealing plate 5 and the above-mentioned upper sealing plate 4 completely cut off the resistive element storage portion 1d from the outside air. Reference numeral 6 denotes a cap-shaped contact fitting that comes into contact with the outer surface 5b of the lower sealing plate 5, and is bonded to the lower sealing plate 5 with a silicone resin adhesive 7. Reference numeral 8 denotes a cap-shaped base metal fitting fixed to the outer circumference 1h of the lower end of the insulator body 1 via an adhesive 39 such as cement, which further covers the lower sealing plate 5 from the outside and further covers the bottom surface of the metal fitting. At the center of 8a, a head 9a is protruded from the inner surface, and a mounting bolt 9, which is fixed integrally by welding, is provided to protrude vertically downward. 10 is a protrusion 8 on the lower end surface 1i of the insulator and the inner surface of the base metal fitting 8.
A buffer bag made of rubber or cork, 11 and 12, is a conductive piece and a coil spring that are interposed between the contact fitting 6 and the upper surface 9a' of the head 9a of the mounting bolt 9, and the resistance element in the storage part is The lower end surface 2c of 2 is the base metal fitting 8 or the mounting bolt 9
When installed, it is electrically connected to the cross arm 13 which is on the ground side. Reference numeral 14 indicates an insulating member with insulation and elasticity filled in the gap between the inner wall surface 1d' of the storage portion 1d and the resistance element 2, and 15 indicates a nut provided on the threaded portion 9b of the mounting bolt 9. .

Further, reference numeral 16 denotes a discharge type fuse tube housed in the fuse accommodating section 1c, which has a slightly smaller diameter than the resistance element accommodating section 1d. It is composed of an inner layer 16a made of generated melamine resin, etc., and an outer layer 16b made of FRP etc. that is closely attached and reinforced from the outside. It is threadedly connected to the threaded part 17b of the arc emitting part 17a, and further, the threaded part 16d at the lower end is threadedly connected to a threaded member 18 fixed to the outer periphery 4a side of the upper sealing plate 4. 19
is a fuse wire stretched inside the fuse tube 16, and one end 19a on the upper side is screwed into the threaded part 1 of the arc discharge part 17a when the screw is connected.
7d, and further connects the other end 19b of the lower side to the upper end surface 2b of the resistance element 2.
Similarly, press connection is made when connecting screws. The wire connection terminal 17 has a fixed part 17b formed in a cap shape, an arc discharge part 17a formed in a small diameter cap shape formed at the center of the upper part of the fixed part 17b, and one side of the fixed part 17b. It consists of a protruding wire connection part 17c, and the insulator body 1
Cover the upper outer periphery of the above fixed part 17b,
It is fixed with an adhesive 20 such as cement. 17a' is an arc discharge port provided in the arc discharge portion 17a, and is provided adjacently above the open end 16e on the upper side of the fuse tube 16;
The discharge port is located at the center of the upper surface of the arc discharge portion 17a which protrudes in the direction. 21 is a pressure relief lid made of a thin plate placed on the locking step 17a'' of the discharge port 17a' from the outside, and 22 is an injection valve that covers the pressure relief lid 21 from the outside to make it watertight. 17c' is a wire holder that protrudes to the side constituting the wire connection part 17c, 23 is a washer made of aluminum or the like fitted into the recess 17c'' of the wire holder, and 24 is a fixed part 17b. One end of the support part 17b' is rotatably attached to the support part 17b' provided in the wire holder 1 with a bolt 25, and the other end of the wire pressing part 24a is
7c', and the horizontal portion 26a of the metal fitting 24 is engaged with an engaging groove _17c1 formed on the lower surface side of the wire holder on the side surface of the metal fitting 24. A notch 24b is formed into which the vertical portion 26b of the matched ⊥-shaped tightening bolt 26 is inserted. 24d is the recess 17 of the wire holder 17c'
a recess formed opposite to c'', 27 is a U-shaped washer, 2
8 indicates a tightening nut provided on the threaded portion 26b' of the vertical portion 26b.

Note that the insulated wire 29 remains in the recess 17 even when the core wire is stripped and the insulation coating is removed.
The wire is clamped and supported between c'' and 24d, and the wire and the wire connection terminal are electrically connected. 30 is a packing made of rubber or cork, and 31 is the outer peripheral surface of the fuse tube 16 and the fuse housing portion 1c. This shows, for example, a silicone-based adhesive having insulation and elasticity that fills the gap formed by the inner peripheral surface of the 33.
indicates an insulating cover.

Next, the operation of the insulator arrester having the above configuration will be explained.

Under normal conditions, only the normal voltage to ground (approximately 4 kV on a 6 kV class distribution line) is applied to resistor element 2, so no current flows through resistor element 2 (actually, very little current flows through resistor element 2). A small amount of leakage current flows, but this can be ignored in practice.)

When an abnormal voltage such as a lightning surge propagates from the above-mentioned normal state, the surge is transmitted to the insulated wire 29.
- Wire connection part 17c of electric wire connection terminal 17, arc discharge part 17a - Fuse wire 19 - Upper sealing plate 4 -
Resistance element 2 - lower sealing plate 5 - contact fitting 6 - conductive piece 11/coil spring 12 - head 9a of mounting bolt 9
- It is released from the base metal fitting 8 and arm metal fitting 13 to the earth via the ground wire.

Furthermore, when the above-mentioned abnormal voltage enters, if it is a large current that exceeds the discharge withstand capacity of the resistance element 2, an external circuit (flash short) occurs in the discharge hole 2a of the resistance element, which causes AC ( (commercial frequency) superimposes and a follow-on arc flows, but at this time,
The upper sealing plate 4 is destroyed by the follow-on arc, and the fuse wire 19 is also broken, but in this case, the increased internal pressure of the fuse tube 16 causes the pressure relief cover 21 of the arc outlet 17a' to close. Since the arc scatters, the arc is immediately emitted outside the main body, and explosion of the insulator body 1 is prevented. As can be seen from the drawing, the voltage nonlinear resistance element 2 used is donut-shaped, so that flash shorting also occurs at the central discharge hole 2a as described above, but as shown in FIG. When a solid element 2' is used, flashover occurs on the outer circumferential surface of the element, so the gap G between the insulating tube 32 and the outer circumferential surface of the element becomes an arc discharge hole.

(Effects of the present invention) The present invention consists of the above configuration, and uses AC (commercial frequency)
Even if a follow-on arc flows, this follow-on current can be quickly blown by the fuse in series with the voltage non-linear resistance element, which prevents the insulator from being damaged by the arc. Explosion accidents can be definitely prevented. In addition, the resistive element and fuse are connected in series in a hollow housing section consisting of a through hole formed in the insulator body, and the resistor element and fuse are stacked one above the other in two layers, making the overall structure more compact. Can be summarized.

Furthermore, if a flash fault occurs in a resistor element and AC is superimposed on the flash fault, causing a follow-on arc to flow, the fuse wire will immediately break as described above, extinguishing this arc. In this case, since the built-in fuse is a discharge type, the pressure built up inside the fuse cylinder immediately scatters the pressure release cover of the arc discharge port, so the pressure built up inside the insulator body is quickly released from this discharge port. Therefore, explosion of the insulator can be reliably prevented.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal half-sectional view of an insulator-type arrester showing an embodiment of the present invention, Fig. 2 is a sectional view of the main part of another embodiment, and Fig. 3 is a side view of the wire connection terminal section of Fig. 1. , FIG. 4 also shows a plan view. 1... Insulator, 2... Voltage nonlinear resistance element,
4... Upper sealing plate, 5... Lower sealing plate, 8... Base metal fitting, 9... Mounting bolt, 16... Discharge type fuse tube, 17... Wire connection terminal, 17a...
Arc discharge part, 17a'...Discharge port, 17b...Fixed part, 17c...Wire connection part, 19...Fuse wire, 21...Pressure release cover.

Claims (1)

[Claims for Utility Model Registration] The insulator body has a hollow housing part, a voltage non-linear resistance element is housed in the housing part, and one end of the resistance element is formed in the upper part of the insulator body. At the same time, a wire connection terminal is fixed for supporting the insulated wire and electrically connecting it, and the lower part is connected to the other end of the resistor element, and the insulator is attached to the armrest of a telephone pole, etc. Fix the base metal fittings for installation,
In addition, in an insulator type arrester that has a mounting bolt and a nut attached to the same base metal fitting, the housing part is formed as a through hole, and a voltage nonlinear resistance element is stored in the lower part of the housing part. A discharge-type fuse cylinder with both ends open is installed in the upper part of the housing, and inside the cylinder is a fuse wire whose one end is connected to the lower end surface of the resistor element and the other end is connected to the electric wire connection terminal. The electric wire connection terminal is provided with an arc discharge port located at the upper opening of the fuse tube and normally closed by a thin pressure relief cover. shaped arrester.