JPH071666B2 - Cut out - Google Patents

Description

The present invention relates to a cutout that protects a transformer and prevents an accident on an electric line, and more particularly, to a cutout having a lightning protection unit built therein.

(Prior Art) Conventionally, a cavity is provided in a main body insulator of a cutout, an outer opening portion of the cavity is sealed, and a non-linear resistance portion or a discharge gap portion is housed in the cavity, and It is known to be compact or beautified.

(Problems to be solved by the invention) However, in a conventional cutout having a lightning protection mechanism, the non-linear resistance portion of the lightning protection unit is damaged due to, for example, an excessive lightning surge, and the continuous current cannot be interrupted, resulting in a continuous current. Occurs,
When a high temperature and high pressure gas generated by the follow-up arc is generated in the cavity of the main body insulator, the main body insulator is destroyed by unbalanced heat and pressure shock and scattered and falls on the ground, which poses a public safety problem.
It is an object of the present invention to provide a cutout having a lightning protection mechanism that solves the above problems.

Configuration of the Invention (Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention relates to a main body insulator made of porcelain having fixed electrodes in the electrode chambers on the power source side and the load side, respectively. In a cutout having a fuse cylinder for connecting or opening fixed electrodes, a cavity communicating with the load side electrode chamber from the outside is provided in the main body insulator, and a cap member capable of releasing the outer opening of the cavity is provided. A gap unit, which is hermetically sealed and has a discharge space hermetically sealed by a pair of discharge electrodes, and a non-linear resistor unit having a through cavity are housed and fixed to each other and connected in series. In addition, a means is adopted in which the discharge space and the penetrating cavity can be opened by the breakage of the discharge electrode.

(Operation) In the present invention, the gap unit, which seals the discharge space with the discharge electrode and the non-linear resistor unit having the through cavity, which seals the cavity with the cap member capable of releasing the pressure, accommodates the gap unit with each other. Since the gaps are fixed and connected in series, and both can be opened by the breakage of the discharge electrode, even if the non-linear resistor unit becomes unable to interrupt the follow current due to an excessive lightning surge, etc. Due to the high temperature and high pressure gas broke through the discharge electrode to open the discharge space and the through cavity, the air in the through cavity was instantaneously heated and expanded to accelerate the pressure and release the gas from the pressure relief cap. , The main body insulator is prevented from scattering and falling.

(Embodiment) An embodiment of the present invention will be described in detail below with reference to the drawings.

In the main body insulator 1 made of porcelain, a power source side electrode chamber 3 and a load side electrode chamber 4 which are partitioned by partition walls 2, 2 are formed. Fixed electrodes 5 and 6 and arc extinguishing chambers 7 and 8 are fixedly embedded in the both electrode chambers 3 and 4 by a filler 9 at their base end portions. Connection terminals 10 and 11 are attached to the fixed electrodes 5 and 6, respectively, and are connected to a power supply side lead wire and a load side lead wire (not shown), respectively.

An insulating lid 12 is openably and closably attached to the open side (lower side in FIG. 1) of the main body insulator 1, and inside the insulating lid 12, a pair of fixed electrodes 5 and 6 are connected or opened. Contact blade 13
A fuse cylinder 13 including a and 13b is detachably attached.

A storage cylinder 21 is integrally formed in the central portion on the back side (upper side in FIG. 1) of the main body insulator 1, and a cavity 21a is formed therein. The cavity 21a is opened at the upper part thereof, is opened at the lower part thereof, and is communicated with the load-side electrode chamber 4 through a guide hole 2a provided in the partition wall 2. Further, a step portion 21b having an opening whose inner diameter is smaller than that of the upper opening is formed on the inner peripheral surface of the cavity 21a.

A lower conductive unit 22, a gap unit 23, a non-linear resistor unit 24, and an upper conductive unit 25 are provided in the cavity 21a.
Are housed in sequence.

Here, the gap unit 23 and the non-linear resistor unit
24 will be described. As shown in FIG. 2, the gap unit 23 is an outer cylinder made of an inorganic material such as porcelain.
26a, and an inner cylinder 26b formed of an inorganic material such as quartz glass, alumina porcelain, or sound-absorbing porous ceramics having heat resistance and impact resistance is disposed inside thereof. Discharge electrodes 27 are arranged on the upper and lower end surfaces of the outer cylinder 26a or the inner cylinder 26b, respectively, and are fixed by glass sealing, brazing or the like to hermetically seal the discharge space 23a in the inner cylinder 26b. An insulating layer 28 is formed between the outer peripheral surface of the gap unit 23 and the inner peripheral surface of the cavity 21a, which is filled with an inorganic material such as low-melting glass and heat-welded together with the main body insulator 1 in a furnace. Has been. This insulating layer 28 is
The space between 23 and 21a is fixed by welding without a gap, and the gap unit 23 is encapsulated.

In the above, the discharge electrode is provided with a bulging discharge end 27a formed by press-molding a metal plate, so that it is easily ruptured by the high temperature or pressure shock of the arc discharge of the follow flow, a thin plate metal is used, Moreover, a notch or the like may be provided.

The non-linear resistance unit 24 includes a non-linear resistance element 29 formed in a cylindrical shape having a cavity 29a made of a sintered product mainly containing zinc oxide (ZnO), and the top surface of the non-linear resistance element 29,
A current collecting electrode 30 made of a soft metal such as a lead plate is joined to the lower surface and between them. The non-linear resistor unit 24 is connected to the gap unit 23 in series via the lower collector electrode 30. An insulating layer 31 having a high elasticity is filled between the outer peripheral surface of the non-linear resistor unit 24 and the inner peripheral surface of the cavity 21a to form an insulating layer 31, and the insulating layer 31 is formed. Thus, the non-linear resistor unit 24 is insulated and enclosed, and is fixed in the cavity 21a and fixed in position integrally with the gap unit 23.

The lower conductive unit 22 includes a gap unit 23 and a storage cylinder.
It is arranged between the step portion 21b of 21. The lower conductive unit 22 is made of a conductive material such as copper or brass, has a spring receiver 32 joined to the stepped portion 21b, and has a guide hole 32a formed at the center thereof. A support cylinder 33 made of a conductive material is joined to the spring receiver 32, and a conductive lid 34 covering the upper opening of the support cylinder 33 is arranged. Between the conductive lid 34 and the gap unit 23, a withstand voltage electrode 35 made of conductive ceramics such as zirconium boride, which can electrically connect the both, is joined.

The conductive rod 36 is provided through the opening of the stepped portion 21b, and a cylindrical contact 37 made of a conductive material is brazed to the upper end of the conductive rod 36 in the central opening. The contact 37
A compression spring 38 made of a conductive material is interposed between the conductive lid 34 and the conductive lid 34, and the conductive lid 34 is pressed against the pressure-resistant electrode 35 by the spring force of the compression spring 38 to electrically conduct the both. A gap S is formed between the conductive lid 34 and the support cylinder 33.

A string-like filler 39 made of glass wool is wound around the outer periphery of the lower conductive unit 22, and the conductive unit
Glass beads 40 are filled between the space 22 and the inner surface of the cavity 21a. The string-shaped filler 39 is the gap unit.
The inorganic insulating material filled to form the insulating layer 28 between the outer periphery of 23 and the cavity 21a is prevented from flowing during heating and melting and entering the inside and outside of the lower conductive unit 22. An O-ring 41 is interposed between the opening of the step portion 21b and the conductive rod 36. An insulator 42 is filled in the lower portion of the cavity 21a, and the opening of the step portion 21b is closed by a silicone sealant 43 filled between the insulator 42 and the O-ring 41. Then, a lead wire 44 for connecting the conductive unit 22 to the load side fixed electrode 6 is attached to the lower end of the conductive rod 36 of the lower conductive unit 22.

Next, the upper conductive unit 25 will be described. The unit 25 is arranged above the nonlinear resistor unit 24 in the cavity 21a, and includes a pair of conductive spacers 45 and 46, which are substantially cylindrical in shape. Leg plate 45a of outer conductive spacer 45
Is bonded to the collecting electrode 30 of the non-linear resistor unit 24, an opening 45b is formed in the center thereof, and the shelf plate 46a formed on the inner conductive spacer 46 and the outer conductive spacer 45 are formed. A desiccant 47 made of silica gel is stored in the space between the leg plate 45a.

A pot-shaped spring receiver 48 made of a conductive material and having an opening 48a at the bottom is joined to the shelf plate 46a of the inner conductive spacer 46, and the opening 48a is closed by a lid 49 made of lead, copper or the like. A compression spring 52, whose upper and lower ends are connected by flexible conductors 52a, is interposed between a cap fitting 51 crimped through an O-ring 50 and the spring receiver 48 at the upper end of the storage cylinder 21. The spring 52 is locked to a hook 51a protruding from the inner surface of the cap fitting 51.

The cap fitting 51 may be provided with a notch or the like so that the gas can be partially melted or ruptured by a high temperature, high pressure gas such as a continuous flow arc generated in the cavity 21a to release the gas.

The upper conductive unit 25 is enclosed by the insulating layer 31 together with the non-linear resistor unit 24, and a silicon sealant 43 is filled between the outer periphery of the upper end of the upper conductive unit 25 and the inner surface of the cavity 21a to form a main body. It is attached to insulator 1. Further, a terminal fitting 53 for connecting a ground wire is provided on the upper surface of the cap fitting 51.

In the cutout configured as described above, the lightning surge generated in the line by the lightning protection unit arranged between the load-side fixed electrode 6 and the ground wire terminal fitting 53 causes the non-linear resistance unit 24 A lightning surge is discharged to the ground through the linear resistance element 29 and the gap unit 23 to suppress the voltage rise, and the follow-up current is also cut off instantaneously.Therefore, a line accident due to a cutout or a flashover in the transformer may occur. To be prevented.

In the present invention, the lightning protection unit becomes unable to interrupt the follow current due to an excessive lightning surge, and when a follow arc occurs, the discharge electrode is melted or broken by the high temperature or pressure shock, and the non-linear resistor unit 24 becomes empty. Opening into the cavity 29a, the air in the discharge space 23a and the cavity 29a is heated and expanded to accelerate the pressure to generate a high temperature, high pressure jet flow. Further, as in the present embodiment, the lower side of the non-linear resistor unit 24, that is, the fuse cylinder side, because the high voltage melting point, the pressure-resistant electrode 35 of conductive ceramics which is less likely to arc damage is arranged,
The gas is shielded by the pressure-resistant electrode 35 and is not ejected downward. Therefore, the gas is effectively accelerated in the direction of the cap fitting 51, and the lid 49 such as the lead plate facing the cavity 29a is melted and the cap fitting 51 is removed. It is bulged and deformed and ejected from the gap of the O-ring 50, or the cap metal fitting 51 is partially melted and ruptured and ejected promptly to prevent the main body insulator 1 from being broken due to unbalanced heat or pressure. Is prevented from scattering and falling.

Further, in this embodiment, each unit 22, 23, 24, 25 is sealed in the cavity 21a through the insulating tanks 28, 31 and integrally fixed to each other, so that moisture absorption is prevented. , Gap unit
23 Change in discharge voltage characteristics and non-linear resistor unit
The deterioration due to the creeping leakage current of 24 can be prevented, and the reliability and durability of the lightning protection unit can be improved.

The upper conductive unit 25 discharges gas from the openings 45b and 48a, but at this time, heat and pressure impact on the opening of the main body insulator 1 are shielded to reduce damage to the main body insulator 1.

Further, in this embodiment, the pressure-resistant electrode 35 and the step portion 21b in the cavity 21a are
Since the contact 37 urged by the compression spring 38 is disposed between the pressure-resistant electrode 35 and the insulating layer 28, when a large gas pressure is applied to the pressure-resistant electrode 35, the pressure-resistant electrode 35 and the conductive layer The lid 34 moves toward the step portion 21b within the range where the gap S is formed, and the pressure shock is absorbed and relaxed by the compression spring 38. Therefore,
The impact resistance of the step portion 21b can be enhanced.

Further, since the desiccant 47 is stored in the upper conductive unit 25 provided on the upper side of the nonlinear resistor unit 24, even if the desiccant 47 absorbs moisture, it can be removed by the desiccant 47. Therefore, it is possible to contribute to suppression of deterioration factors of the non-linear resistance element 29.

In addition, in this embodiment, since the gap unit 23 is arranged closer to the pressure-resistant electrode 35 than the non-linear resistor unit 24, the high temperature and high pressure gas generated in the gap unit 23 are instantaneously regulated in one direction. It can be effectively released.

In this embodiment, when the lower conductive unit 22 and the gap unit 23 are mounted in the cavity 21a, the spring receiver 32, the support cylinder 33 and the compression spring 38 are sequentially housed in the cavity 21a, It is placed on the stepped portion 21b. Next, the previously integrated conductive rod 36 and contact 37 are inserted into the cavity 21a, the conductive rod 36 is inserted into the guide hole 32a of the spring receiver 32 and the opening of the step portion 21b, and the contact Engage 37 with the top of compression spring 38. In this state, the contactor 37 moves the compression spring 38
By the spring force of the above, it is held at a position projecting upward from the upper end of the support cylinder 33.

Next, the conductive lid 34 and the pressure-resistant electrode 35 are superposed on the contactor 37, and a string-shaped filler 39 and glass beads 40 are provided between the outer periphery of the pressure-resistant electrode 35 and the support tube 33 and the inner surface of the cavity 21a. Fill.
Then, after disposing the gap unit 23 on the pressure-resistant electrode 35, the conductive rod 36 is pulled downward against the spring force of the compression spring 38, and its contact 37 is separated from the conductive lid 34,
With the opposite ends of the conductive lid 34 and the support cylinder 33 in contact with each other,
An inorganic material for the insulating layer 28 is filled between the gap unit 23 and the cavity 21a. At this time, the material is the string-like filler 39
Since it is blocked by the above, it will not penetrate into the inside and outside of the lower conductive unit 22 even if it is melted as described later.

Then, if the inorganic material is heated and melted in the above state, the insulating layer 28 is formed between the gap unit 23 and the cavity 21a, the gap unit 23 is fixed, and the support cylinder 33 and the conductive lid are cooled according to cooling. A gap S is formed with 34.

Effects of the Invention As described in detail above, according to the present invention, a gap unit in which a gap electrode is easily broken by a continuous arc in a cavity and a non-linear resistor unit in which the cavity communicates with the gap unit. Since they were housed and fixed in series with each other and connected in series, when the continuous current interruption capability of the non-linear resistor unit deteriorates due to excessive lightning surge and high temperature and high pressure gas are generated by the continuous arc, this Since the gas heats and expands the air in the cavity to accelerate the pressure to the cap member side, and the gas is released through the cap member to release the pressure, it is possible to prevent the main body insulator from scattering and falling, which is excellent in safety. Be effective.

[Brief description of drawings]

FIG. 1 is a sectional view of a cutout embodying the present invention,
FIG. 2 is an enlarged sectional view of a main part of the cutout. In the figure, 1 ... Main body insulator, 3 ... Charge side electrode chamber, 4 ... Load side electrode chamber, 5, 6 ... Fixed electrode, 13 ... Fuse cylinder, 21a ... Void, 23
... Gap unit, 23a ... Discharge space, 24 ... Non-linear resistance unit, 27 ... Gap electrode, 29 ... Non-linear resistance element, 29a ... Through cavity, 35 ... Withstand voltage electrode, 51 ... Cap metal fitting.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Eiichi Yanagisawa 2-1, Ogimachi, Meito-ku, Nagoya, Aichi (72) Inventor Kazuaki Kato 606 (72) Inventor, 1 Tabuchi, Hachiman, Chita, Aichi Chihiro Ishibashi 3-17, Maruikedai, Ogawa, Higashiura-cho, Chita-gun, Aichi Prefecture (72) Inventor Junichi Matsumoto 2-38-2, Okamachi, Mizuho-ku, Aichi Prefecture Nagoya (72) Inventor Akashigawa Akiyoshi Gifu Prefecture 2 No. 1258, Oura, Masaki-machi, Hashima City (72) Inventor Mitsuyoshi Nagase No. 8 of 127 Nakahata, Minamishinmachi, Owariasahi-shi, Aichi

Claims (1)

[Claims] 1. A porcelain body insulator (1) having fixed electrodes (5, 6) in the electrode chambers (3, 4) on the power source side and the load side, respectively.
And a cutout having a fuse cylinder (13) for connecting or disconnecting the fixed electrodes (5, 6), a cavity communicating with the main body insulator (1) from the outside to the load side electrode chamber (4) (21a) is provided, the outer opening of the cavity (21a) is sealed by a pressure-releasable cap member (51), and a pair of discharge electrodes (27, 27) are provided in the cavity (21a) for discharging. A gap unit (23) that hermetically seals a space (23a) and a non-linear resistor unit (24) having a through cavity (29a) are housed and fixed to each other and connected in series, and A cutout characterized in that the discharge space (23a) and the through cavity (29a) can be opened by a break of the discharge electrode (27, 27).