JPH071668B2 - cut out - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention (Field of Industrial Application) The present invention relates to a cutout having a lightning protection unit built therein.

(Prior Art) As a cutout with a built-in lightning protection unit,
There is a body insulator in which a cavity communicating with the load-side electrode chamber from the outside is provided, and a lightning protection unit housed in the cavity is connected to a fixed electrode on the load side by a connection conductor. However, with this conventional cutout, when the lightning arrester becomes unable to interrupt the follow current due to an excessive lightning surge, and high temperature and high pressure gas is generated by the follow arc, the gas is ejected to the fuse cylinder side and the fuse cylinder There was a problem that the main body insulator was crushed due to the unbalanced heat and pressure shock due to the jetted gas, and was scattered and dropped on the ground.

Therefore, in order to solve the above problems, the applicant has created the cutout shown in FIG. The cutout will be described with reference to the reference numerals in the examples described later. The cavity of the storage cylinder 21 formed in the center of the rear surface side of the main body insulator 1.
A gap unit 23 having a discharge electrode 27 is provided in 21a.
And a lightning protection unit including a non-linear resistor unit 24 having a tubular non-linear resistance element 29 are connected and arranged in series, and are respectively enclosed in insulating layers 28 and 31. The cavity 2
Between the stepped portion 21b formed on the inner peripheral surface of 1a and the gap unit 23, there is a withstand voltage electrode 35 made of conductive ceramics.
And a bottom plate 55 made of metal and the both 35, 55 are joined to each other, the pressure-resistant electrode 35 is connected to the non-linear resistor unit 24.
A bottom plate 55 is joined to the step portion 21b via a sheet 56 on the lower surface of the. The withstand voltage electrode 35 is enclosed in the insulating layer 28, and a string-like filler 39 is provided between the bottom plate 55 and the inner surface of the cavity 21a.
Is filled.

A connection terminal 57 is projectingly provided on the bottom plate 55 and inserted into the opening of the step portion 21b. The conductive plate 58 fixed to the upper end of the connection terminal 57 is bonded to the withstand voltage electrode 35 while being arranged in the gap between the withstand voltage electrode 35 and the bottom plate 55, and the connection terminal 57 is connected.
The lower end of is connected to the fixed electrode on the load side by a lead wire 44. Further, a compression spring 52, whose upper and lower ends are connected by a flexible conductor 52a, is interposed between a cap fitting 51 mounted on the peripheral edge of the upper opening of the storage cylinder 21 and the non-linear resistor unit 24 via a spring receiver 64. The non-linear resistor unit 24 is grounded via the compression spring 52 and the terminal fitting 53 on the cap fitting 51.

Further, the gap unit 23 includes an outer cylinder 26a, and two inner cylinders 26b are arranged inside the outer cylinder 26a. The discharge electrodes 27 are fixed to both upper and lower end surfaces of both inner cylinders 26b,
A compression spring 59 made of a conductive material is interposed between the pair of discharge electrodes 27 facing each other between the inner cylinders 26b. Further, the non-linear resistance unit 24 includes two non-linear resistance elements 29, and the upper electrodes 60,
It has an intermediate electrode 61 and a lower electrode 62. Both units 2
A conductive spacer 63 made of conductive ceramics having an opening in the center is interposed between 3 and 24.

Therefore, with this cut-out, the lightning protection unit cannot shut off the follow-up current due to excessive lightning surge, and when high temperature and high pressure gas is generated by the follow-up arc, the gas has a high melting point and is resistant to arc damage. One is shielded by the electrode 35 and jetted toward the other cap metal fitting 51 side, and the cavity 21a is released through the cap metal fitting 51, so that the blowout of the fuse cylinder and the scattering and dropping of the main body insulator are prevented.

However, in this cutout, the pressure shock of the high temperature and high pressure gas generated in the cavity 21a is caused by the pressure resistant electrode 35 and the bottom plate.
Since it is directly added to the step portion 21b through 55, the step portion 21b
There is a risk that the cracks may occur or cracks may occur in the entire main body insulator 1.

The present invention was made in consideration of the above circumstances,
The purpose is to provide a cutout that can absorb and mitigate the pressure shock from the lightning protection unit applied to the main body insulator 1 when it becomes impossible to interrupt the follow current due to excessive lightning surge, and improve its shock resistance. To do.

Configuration of the Invention (Means for Solving the Problems) In order to achieve the above object, in the present invention, a cavity that communicates with the load-side electrode chamber from the outside is provided in the main body insulator, and a lightning arrester is provided in the cavity. A shock absorbing member is disposed between the step portion formed inside the cavity and the lightning protection unit while accommodating the unit, and the shock absorbing member is a cylindrical support member supported by the step portion. A conductive plate disposed between the lightning protection unit and the cylindrical support, a conductive rod penetrating the stepped portion and penetrated by the cylindrical support, and the conductive rod through the conductive plate. The lightning protection unit comprises a contactor that is in close contact with the lightning protection unit and is urged by a compression spring that repels between the conductive plate and the cylindrical support, and the lightning protection unit is connected to the load side fixed electrode through the conductive rod. It has adopted the configuration of connecting to.

(Operation) Therefore, when the lightning surge unit becomes unable to interrupt the follow current due to an excessive lightning surge and high temperature and high pressure gas is generated in the cavity due to the follow arc, one of the gases is shielded by the shock absorbing member, and the shock The pressure shock applied to the conductive plate of the relaxation member is absorbed or mitigated by the biasing force of the spring within the range of maintaining the elastic force between the support and the cylindrical support, thus preventing the pressure shock from being directly applied to the stepped portion. The insulator body is protected.

(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.

Inside the cavity 21a, a lower conductive unit 22, a gap unit 23, and a non-linear resistor unit 24 that constitute an impact absorbing member.
And the upper conductive unit 25 are sequentially accommodated.

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 fixed to the upper and lower end surfaces of the outer cylinder 26a or the inner cylinder 26b, respectively. Further, between the outer peripheral surface of the gap unit 23 and the inner peripheral surface of the cavity 21a, an insulating layer 28 formed by being filled with an inorganic material such as low melting point glass and heated and melted in a furnace together with the main body insulator 1 is provided. Has been. The insulating layer 28 is welded and formed between the two 23, 21a without any gap, and the gap unit 23 is insulated and enclosed.

The non-linear resistance unit 24 includes a non-linear resistance element 29 formed in a cylindrical shape having a lumen 29a made of a sintered product mainly containing zinc oxide (ZnO), and the top surface of the non-linear resistance element 29,
A collector electrode 30 made of a lead plate is joined to the lower surface and between them. The non-linear resistor unit 24 is the lower collector electrode.
It is joined in series to the gap unit 23 via 30. The outer peripheral surface of the nonlinear resistor unit 24 and the cavity 21a
An insulating material having a high elasticity is filled between the inner peripheral surface and the inner peripheral surface to form an insulating layer 31, and the non-linear resistor unit 24 is insulated and enclosed by the insulating layer 31.

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 cylindrical support 33 made of a conductive material is joined on the spring receiver 32,
A conductive plate 34 covering the upper opening of the cylindrical support 33 is arranged. Between the conductive plate 34 and the gap unit 23, a withstand voltage electrode 35 made of a conductive ceramic such as zirconium boride that can electrically connect the both 34, 23 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 plate 34 and the conductive plate 34, and the conductive plate 34 is pressed against the pressure-resistant electrode 35 by its spring force to electrically connect the two together. A gap S is formed between the conductive plate 34 and the cylindrical support 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 filler 39 prevents the inorganic insulating material filled to form the insulating layer 28 between the outer periphery of the gap unit 23 and the cavity 21a from 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 a silicone sealant filled between the insulator 42 and the O-ring 41.
The opening of the step portion 21b is closed by 43. And
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 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. At the upper end of the storage cylinder 21, a cushion material 50
Cap metal fitting 51 and the spring bearing
A compression spring 52, whose upper and lower ends are connected by flexible conductors 52a, is interposed between the spring 48 and the spring 48, and the spring 52 is a cap fitting 51.
Is hooked on a hook 51a protruding from the inner surface of the.

The cap fitting 51 is preferably 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, when a lightning surge enters the lightning protection unit arranged between the load-side fixed electrode 6 and the ground wire terminal fitting 53, the non-linearity of the non-linear resistor unit 24 is increased. A lightning surge is discharged to the ground through the resistance element 29 and the gap unit 23 to suppress a voltage rise, and a line failure due to a cutout or a flashover in a transformer is prevented.

In this embodiment, since each unit 22, 23, 24, 25 is sealed in the cavity 21a via the insulating layers 28, 31, moisture absorption is prevented and the discharge voltage characteristic of the gap unit 23 is reduced. It is possible to prevent fluctuations and deterioration due to creeping leakage current of the nonlinear resistor unit 24, and improve the reliability and durability of the lightning protection unit.

Further, when the lightning protection unit becomes unable to interrupt the follow current due to an excessive lightning surge or the like, and a follow arc occurs, the air in the lumen 29a of the non-linear resistor unit 24 is heated and expanded to become high temperature and high pressure, In the present embodiment, since the pressure-resistant electrode 35 made of conductive ceramics, which has a high melting point and is resistant to arc damage, is arranged below the nonlinear resistor unit 24, that is, on the fuse cylinder 13 side, the gas is a pressure-resistant electrode. It is not ejected below 35, and therefore the insulating lid 12 and the fuse cylinder 13 are protected and the blowout is prevented. The high-temperature, high-pressure gas, which is prevented from being ejected downward by the pressure-resistant electrode 35, melts the lid 49 on the spring receiver 48 facing the inner cavity 29a and bulges and deforms the cap fitting 51 to eject from the gap of the cushion material 50. Alternatively, the cap fitting 51 is partially melted and ruptured to alleviate the unbalanced heat and pressure impact on the main body insulator 1 and prevent the cutout from scattering and dropping.

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 plate 34 moves to the step portion 21b side within the range where the gap S is formed, that is, within the range where the elastic force between the plate 34 and the cylindrical support 33 can be maintained by the urging force of the compression spring 38, and the pressure impact is generated. It is possible to prevent the main body insulator 1 from being directly applied, and thus it is possible to improve the impact resistance of the main body insulator 1.

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 instantly directed in one direction. As a result, the pressure can be accelerated and the gas 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 cylindrical support 33 and the compression spring 38 are sequentially accommodated in the cavity 21a, They are arranged on the step portion 21b. Next, the previously integrated conductive rod 36 and contactor 37 are inserted into the cavity 21a, and the conductive rod 36 is inserted into the guide hole 32a of the spring receiver 32 and the step portion 21b.
The contact 37 is engaged with the upper end of the compression spring 38 while being inserted through the opening of the. In this state, the contact element 37 is held by the spring force of the compression spring 38 at a position protruding above the upper end of the tubular support 33.

Next, the conductive plate 34 and the pressure-resistant electrode 35 are superposed on the contactor 37, and a string-like filler 39 and glass beads are provided between the outer periphery of the pressure-resistant electrode 35 and the cylindrical support 33 and the inner surface of the cavity 21a. Fill 40. 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 the contact 37 thereof is separated from the conductive plate 34, so that the conductive The insulating layer 2 is provided between the gap unit 23 and the cavity 21a while the plate 34 and the tubular support 33 are in contact with each other at their opposite ends.
Fill with 8 inorganic materials. At this time, even if the material is melted as will be described later, the material is blocked by the string-like filler 39, so that the material does not enter the inside and outside of the lower conductive unit 22.

Then, when 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 tubular support is provided by contraction of each part by cooling. A gap S is formed between the body 33 and the conductive plate 34. It should be noted that a high melting point glass cloth or the like is previously interposed between the opposing ends of the cylindrical support 33 and the conductive plate 34 to expand the gap S to expand the elastic force maintaining range and absorb the pressure shock. You can also increase the effect.

As described above in detail, according to the present invention, the body insulator is provided with the cavity communicating with the load side electrode chamber from the outside, and the lightning protection unit is accommodated in the cavity and is formed inside the cavity. Since a shock absorbing member is placed between the stepped part and the lightning protection unit, the lightning protection unit cannot shut off the follow-up current due to an excessive lightning surge, and when the high-temperature and high-pressure gas is generated by the follow-up arc, the shock absorption is mitigated. It is possible to prevent the high temperature and high pressure gas from being blown out toward the fuse cylinder side by the member and absorb and relieve the pressure shock applied to the step inside the cavity to improve the shock resistance of the insulator body. It is possible to prevent the blowout of the fuse cylinder and the scattering and dropping of the main body insulator by ejecting the fuse cylinder.

Further, since the shock absorbing member elastically supports the pressure shock transmitting member by the spring, the shock absorbing ability can be significantly improved as compared with a cushion sheet or the like.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a cutout embodying the present invention, FIG. 2 is an enlarged sectional view of an essential part, and FIG. 3 is a view corresponding to FIG. 2 of a conventional 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, 22 ... Lower conductive unit as shock absorbing member, 23 ... Gap Unit, 24 ... Non-linear resistance unit (the lightning protection unit is constituted by 23 and 24), 33 ... Cylindrical support, 34 ...
Conductive plate, 36 ... Conductive rod, 38 ... Compression spring, S ... Gap.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Eiichi Yanagisawa 2-chome, Ogimachi, Meito-ku, Nagoya, Aichi (72) Inventor Hiromi Nagasaka 35th, Izoji, Higashiura-cho, Chita-gun, Aichi (72) Inventor 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 lightning protection unit (23, 24) is housed in the cavity (21a), and the cavity (21a) is also provided.
Of the lightning protection unit (23, 2)
A shock absorbing member (22) is arranged between the shock absorbing member (22) and the cylindrical support (33) supported by the step portion (21b) and the lightning protection unit (23). , 24) and the cylindrical support (33), and a conductive rod (34) penetrating the cylindrical support (33) through the step (21b). 36) and the conductive rod (36) in close contact with the lightning protection unit (23, 24) via the conductive plate (34), and between the conductive plate (34) and the cylindrical support (33). The lightning protection unit (23, 2) is composed of a contactor (37) urged by a compression spring (38) to be repelled, and the conductive rod (36).
Cutout characterized in that 4) is connected to the fixed electrode (6) on the load side.