JPH10178706A - Pressure-releasing device for pole-mounted switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to quickly and safely release the inner pressure to outside a case in the early stage of the rise of inner pressure at the occurrence of an internal short-circuit. SOLUTION: A pressure-releasing hole 50b is formed on an upper plate 50 of the main body case of a switch, and a pressure-releasing lid 51 is fitted to this hole 50b in an airtight and detachable manner. In order to separate the pressure-releasing lid 51 from the pressure releasing hole 50b in an early stage of the internal pressure rise during an internal short-circuit, a retaining member 54 for retaining and holding the pressure-releasing lid 51 is provided. At the outside of the pressure-releasing lid 51, a space (a) is provided, and a protective lid 12 covering the pressure-releasing lid 51 is used to cover the pressure-releasing lid 51. An external directed pressure-releasing hole 12a opened diagonally upward is made in the protective lid 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a pressure relief device for a pole switch used in a high-voltage or extra-high voltage distribution line.

[0002]

2. Description of the Related Art In a pole switch, a pressure relief device (pressure relief structure) for protecting a case is provided for safety reasons. This pressure relief device protects the case by releasing the internal pressure increased by the arc generated at the time of the internal short circuit to the outside of the case to prevent the case deformation and the case destruction.

[0003]

By the way, in recent years, this type of pole switch has been reduced in size and weight in order to improve workability or transportability. The inner volume of the (body case) is small. Therefore, if an internal short circuit occurs due to a lightning surge, etc., and the arc is excessive (when the short-circuit current is large), the pressure relief device cannot sufficiently cope with a sudden increase in the internal pressure of the case, and the pressure relief operation is delayed. This can lead to case deformation and case damage.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to solve the above problem. Pressure device.

[0005]

According to a first aspect of the present invention, a pressure relief port is provided on an upper plate (50) of a main body case (4) of a switch (1). (50b), a pressure-release lid (51) is airtightly and removably fitted to the pressure-release port (50b), and the pressure-release lid (51) is formed in an initial stage of internal pressure rise at the time of internal short circuit. ) Is the pressure relief port (5
0b), a fastening member (54) for fastening and holding the pressure release lid (51) is provided, and a space (a) is provided outside the pressure release lid (51) to provide a pressure release lid (51). ) Is provided, and an external pressure release port (12a) that opens diagonally upward is formed in the protective lid (12).

According to a second aspect of the present invention, in the first aspect, the fastening member (54) is formed of a metal plate, and its base is fixed to the upper plate (50). Pressure relief lid (5
It is locked on the peripheral edge of the upper surface of 1).

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described based on the embodiment shown in FIGS. As an embodiment, a case where the present invention is applied to a construction gas switch, which is a type of pole switch, will be described.

1 to 3, reference numeral 1 denotes a construction gas switch, 2 denotes an operation handle, and 3 denotes a screw portion of a mounting ring 5 fixed around a bushing of a main body case 4. 6, a bushing protection unit made of aluminum metal screwed to the bracket, 6 is a transport guard, 4 is a main body case, 7 is a lock display window, 8 is a handle lock string with a hook 9 tied to the tip, 10 is an installation leg, 11 Denotes a mounting bracket for mounting the switch on a utility pole, and 12 denotes a protective cover of a pressure release device (pressure release structure) 13 provided on the upper part of the main body case.

FIGS. 4 and 5 show the internal structure.
Is a main body case made of stainless steel in which a switch unit 15 is accommodated in an upper part and an operation mechanism part 16 is accommodated in a lower part. The switch unit 15 has a predetermined pressure (0.6 atm at room temperature of 20 ° C.). For example, an arc-extinguishing gas 17 such as SF6 gas is filled. Reference numerals 18 and 19 denote a power-supply-side bushing and a load-side bushing made of epoxy resin attached to both side surfaces 4a and 4b of the main body case respectively in a penetrating state, and 20 denotes a flange-shaped flange fitting for mounting the bushing to the main body case 4. Yes, bushing (insulator)
Some have been inserted. 22 is a mounting screw, 23
Denotes a mounting nut, and 28 denotes an airtight rubber packing interposed between the bushing and the case penetration portion.

Reference numeral 30 denotes a two-blade movable electrode,
One end 30a of the electrode is rotatably supported by a pin 32 on the case inner end 31a side of the center conductor 31 of the power supply side bushing 18 by a pin 32. The contact surface 3 on the other end of the movable electrode 30
0c contacts and separates from the contact surface 34a of the fixed electrode 34 fixed to the inner end side of the case of the center conductor 33 of the load-side bushing to open and close the electric circuit.

Reference numerals 35 and 36 denote EPTs inserted through the inner ends of the case of the central conductors of the power source side and the load side bushing,
A shield formed of an insulating member such as neoprene rubber or epoxy resin and having a surface formed with irregularities for increasing a creepage distance, and the shield is inserted into a center conductor and has a leading end surface 19a of a bushing. (18a) is tightly bonded with an adhesive.

A connecting mechanism 37 connects the operating mechanism 16 and the movable electrode 30 to each other. Reference numeral 38 denotes a driving shaft, and 39 denotes an insulating lever made of an insulating member. The lever 39 connects the movable electrode 30 and the driving shaft 38. Reference numeral 40 denotes a partition plate that hermetically insulates the switch unit 15 and the operation mechanism unit 16 from each other.
Are integrally fixed to the inner peripheral surface 4d of the case by welding to partition the inside of the main body case 4 into upper and lower portions.

Reference numeral 41 denotes a bellows for detecting gas leakage, which is installed on the partition plate 40 such that the detecting portion is located on the side of the switch portion 15, and an operating pin 42 on the operation mechanism portion side is operated by detecting the bellows. The operation mechanism 16 is operated and locked,
The opening / closing operation of the operation handle 2 is prevented, and the display body 43 rotates simultaneously with the blocking of the opening / closing operation, so that the locked state can be visually recognized from the outside of the case through the display window 7 located at the lower part of the case. I have. Reference numeral 44 denotes a contact pressure adjusting spring for the movable electrode 30.

Reference numeral 45 denotes an arcing horn plate made of a metal having good thermal conductivity, for example, a copper plate or a painted steel plate, which is screwed to the inner peripheral surface 4e of the case orthogonal to the bushing. The plate is constituted by a shielding part 45a and a horn part 45b that cover the inner peripheral surface 4e of the case, and the horn part is fixed. The tip 45c is provided to face the fixed electrode 34 of the load-side bushing 19 to induce and fix arcing. The two adsorbents 46 of activated alumina and zeolite contained in a wire mesh bag or the like are stored in the lower surface side of the shielding portion 45a using a space so as not to fall off.

Reference numeral 47 denotes an opening of the operation mechanism, that is,
In order to close the lower end opening 4f of the main body case 4,
The bottom cover is made of a stainless steel plate of the same material as that of the main body case 4 and hermetically attached to f.

Reference numeral 50 denotes a flange-shaped upper plate made of a stainless steel plate, which is formed in an annular shape having a hole at the center thereof, and a joint 50a formed therearound is put on the joint 4h on the main body case side. Between the peripheral ends 50a 'and 4h'
It is provided by being integrally fixed by G welding and constitutes a part of the main body case. Reference numeral 50b denotes a pressure hole having a round hole shape formed in the center of the upper plate 50, and a ring-shaped reinforcing metal member 53 is fixed to the inner peripheral surface of the pressure hole 50b.

Reference numeral 51 denotes a pressure-release lid, which is a closure plate 51a having a diameter larger than the diameter of the pressure-release port 50b, an annular joining member 51b fixed around the lower surface of the closure plate 51a, and a periphery of the lower surface of the closure plate 51a. And a sealing member 62 for maintaining airtightness. A groove 51c is formed on the outer peripheral surface of the joining member 51b, and an O-ring 52 is fitted in the groove 51c.

The outer diameter of the joining member 51b is formed so as to be pressed into the inner peripheral surface of the reinforcing member 53 via the O-ring 52. Further, a projecting portion 51f projecting outward is integrally formed on an upper portion of the joining member 51b, and the projecting portion 51f is adapted to be engaged with the upper surface of the reinforcing metal member 53.

Then, as shown in FIG.
b is press-fitted into a reinforcing bracket 53 via an O-ring 52 and a pressure-release lid 51 is attached, so that the pressure-release port 50 b is closed by the pressure-release lid 51.

Reference numeral 54 denotes a fastening piece forming a fastening member.
As shown in FIG. 1, it is formed of a thin elastic member, for example, a stainless steel plate, and is bent up and down a little near the center thereof. The upper end has a holding portion 54h, a mounting hole 54a is formed in the center, and a notched positioning portion 54g is formed at the rear end.

Each of the above-mentioned fastening pieces 54 is attached to each of the mounting bolts 55 standing at three places (equally spaced at 120 degrees) on the upper plate 50 by fitting the positioning portions 54g thereof to the fixing bolts 58.
Is fitted through the mounting hole 54a. Thereby, the pressing portion 54h of each fastening piece 54 is directed toward the center of the pressure release lid 51, and the peripheral edge 5e of the peripheral upper surface 51e of the upper plate 51a.
1e '.

Then, as shown in FIG.
A fitting 56 having a U-shaped cross section as shown in FIG. 4 is fitted to the mounting bolt 55 through the mounting hole 56a, and a nut 57 is screwed to the mounting bolt 55 from the upper part thereof.
4 is attached.

Thus, the holding portion 54h of the fastening piece 54
As a result, the peripheral edge 51e 'of the pressure release lid 51 is elastically pressed from above with a predetermined pressing force. The pressing portion 54h is set to have such a strength that it is bent upward by the initial stage internal pressure when the internal pressure is increased due to an internal short circuit.

In the above description, the pressure release lid 51 is locked at three places by the fastening pieces 54. However, the size of the pressure release port, the size (area) of the pressure release lid 51, and the release force (release The fixing means is appropriately changed depending on, for example, the force of releasing the pressure-release lid from the pressure port, and is not limited to three places.

A protective cover 12 is provided above the pressure release cover 51. As shown in FIGS. 7 and 8, the protective lid 12 has a top plate 12g in the center, a slope 12b inclined downward on the outer periphery, and a flat portion 1b on the outside.
It has a lower peripheral wall 12c that is suspended following 2h, and these are integrally formed in a cap shape with a single metal plate. The protective lid 12 is formed of a metal plate having a mechanical strength enough to withstand the internal pressure due to an internal short circuit, for example, a steel plate, a stainless steel plate, or the like.

A plurality of outside pressure discharge ports 12a are formed on the slope 12b at appropriate intervals in the circumferential direction, and the outside pressure discharge ports 12a open obliquely upward. The external pressure release port 12a can prevent insects, birds, and the like from entering, and at the time of pressure release, can prevent small pieces of the assembly components in the case as well as the pressure release lid from jumping out of the container. It is formed in a small diameter mouth. Specifically, it is desirable to provide a large number of small-diameter shapes as shown in the figure, but the invention is not limited to the shape shown in the figure. Further, mounting holes 1 are provided in the flat portions 12h.
2f is formed.

The diameter of each part of the protective cover 12 is set as shown in FIG. 8 in relation to the upper plate 50, and its mounting hole 12f matches the mounting bolt 58, and the lower peripheral wall 1
2c is set at the joint 50a of the upper plate 50, and the lower end 12d of the lower peripheral wall 12c is
Is set so that a slight gap C is formed between the upper plate 50 and the upper surface of the joint 50a in the attached state.

The protective cover 12 is attached to the upper plate 5.
0 and concentrically over the upper part of the pressure-releasing lid 51, and the mounting hole 12 f is inserted through a fixing bolt 58 erected on the upper plate 50, and then the nut 5 is inserted into the fixing bolt 58 through a washer.
9 is attached to the fixing bolt 58 by tightening.
At this time, the protective cover 1
2, the mounting position (height) of the protective lid 12 is regulated, and a predetermined gap C is formed between the lower end 12d of the protective lid 12 and the joint 50a of the upper plate 50. The rainwater that has entered through the external pressure release port 12a
From the vessel immediately.

Reference numeral 60 denotes a heat shield plate made of a stainless steel plate or a steel plate.
0, and is fixed to the upper plate 50 by screws 61 with a small space s so that the arc generated in the case does not directly reach the inner surface of the upper plate 50. I have.

Next, the pressure releasing operation of the pressure releasing device will be described. When an internal short circuit occurs in the main body case due to the intrusion of a lightning surge or the like, the arcing is guided and fixed to the arcing horn plate 45 provided with a horn, concentrated at such a location, and the other case surface (side surface orthogonal to the bushing). ) Is not affected by arcing. That is,
In other cases, holes due to arcing concentration are prevented.

When the pressure inside the case suddenly rises due to the arcing, the above-described pressure acts on the inner surface of the pressure-releasing lid 51 in which the upward movement has been stopped by the fastening pieces 54 until now. When the internal pressure in the initial stage of the increase of the internal pressure acts on the fastening piece 54 via the pressure release lid 51, the holding portion 54h of the fastening piece 54 is pressed and bent upward in a portion near the holding metal fitting 56, and FIG. Pressure release lid 5 as shown in
1 is released from the pressure release port 50b at once, collides with the inner surface of the top plate 12g of the protective cover 12, the pressure release port 50b is fully opened, and the protective cover 12 causes the pressure release lid 51 to jump out of the container. Will be blocked. Due to the entire opening of the pressure release port 50b,
The arc and the internal pressure are released from the external pressure release port 12a to the outside of the case (protective lid) through the internal space a of the protective lid 12.

At this time, the external pressure release port 12b is
2b, which opens diagonally upward,
The internal pressure or the like to be released is released obliquely upward as indicated by the arrow in FIG. Furthermore, even if a small piece of the assembly member in the case scatters from the pressure release port 50b, it is finally screened by the protective lid 12, so that the small piece and the like outside the case can be prevented from scattering as much as possible.

In the pressure releasing operation, when an internal short circuit occurs, the internal pressure (internal pressure) rises from 0.6 atm under normal (normal) pressure to 7 atm to 1 atm.
When the pressure reaches about 0 atm, in other words, at the initial stage of the pressure increasing process within three cycles from the occurrence of the short circuit, the pressure release lid 51 is separated from the pressure release port 50b at a stretch, and the pressure release operation is started. I have. However, the body case 4 of the embodiment of the present application
Has sufficient mechanical strength to withstand up to 20 atm.

When the fastening piece 54 is formed of a plate having a spring property, when the internal pressure of the case slightly rises due to an increase in the outside air temperature in a normal state, the fastening piece 54 deflects slightly upward. When the internal pressure is restored to the original pressure, the pressure release lid 51 can be returned to the original state by the spring pressure of the fastening piece 54.

In the normal state, when rainwater enters through the external pressure release port 12a, the rainwater is released from the pressure release cover 51a.
As a result, intrusion into the case is prevented and the air is discharged from the gap C to the outside of the case.

The external pressure release port 12 in the above embodiment is used.
When a screen member such as a punching metal is stretched over a, the invasion of insects, birds, and the like can be further prevented, and the small pieces of the above-mentioned assembly member can be further prevented from flying outside the container.

In the above embodiment, the fastening member 5
4 is formed of a fastening piece made of a plate piece,
Alternatively, the O-ring 52 may be used as a fastening member without providing the fastening piece, and the pressure-releasing lid 51 may be fastened by the pressing force of the O-ring 52. A leaf spring may be interposed between 53 and the pressure release lid 51 may be fixed by the spring pressure.

[0038]

As described above, according to the first aspect of the present invention, the pressure release lid is detached in the initial stage of the increase of the internal pressure, the pressure release port is promptly opened to the entire surface, and the body case is closed. Extreme expansion is prevented, and deformation and breakage of the main body case can be reliably prevented.

Further, since the outside of the pressure-release lid portion, which is also a mechanical weak point, is covered with the protective lid, direct external force is prevented from being applied to the pressure-release lid portion even during transportation or construction. Does not impair the airtightness of the part.

Further, the external pressure release port formed in the protective lid is
Since the opening is obliquely upward, the arc or the like is released obliquely upward when the pressure is released, so that the pressure can be prevented from being released to the side where a pedestrian or the like passes. According to the second aspect of the present invention, even when the internal pressure of the case rises within the normal operating pressure, the fastening piece is bent and the internal pressure can be favorably absorbed.

[Brief description of the drawings]

FIG. 1 is a front view of an embodiment in which the present invention is applied to a construction gas switch.

FIG. 2 is a side view of FIG.

FIG. 3 is a plan view of FIG. 1;

FIG. 4 is a vertical cross-sectional view partially omitted in the same manner.

FIG. 5 is a cross-sectional view of the pressure relief device as viewed from below in FIG. 4;

FIG. 6 is an inner (lower) view of the protective lid.

FIG. 7 is a sectional view taken along the line AA in FIG. 6;

FIG. 8 is a sectional view of a main part before a pressure releasing operation of the pressure releasing device.

FIG. 9 is a cross-sectional view of a main part of the pressure release device during a pressure release operation.

FIG. 10 is a plan view of the pressure relief device with the protective lid removed.

FIG. 11 shows a fastening plate, wherein (a) is a plan view,
(B) is a side view.

12A and 12B show a pressing plate, wherein FIG.
(B) is a side view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Switch 4 Main body case 12 Protective lid 12a External pressure release port 12b Slope part 13 Pressure relief device 50 Upper plate 50b Pressure relief port 51 Pressure relief lid 54 Fastening member 54h Holding part

Claims (2)

[Claims] 1. A pressure release port is formed in an upper plate of a main body case of a switch, and a pressure release lid is air-tightly and detachably fitted to the pressure release port, and an initial pressure rise at the time of internal short circuit occurs. At the stage, a fastening member for fastening and holding the pressure-release lid is provided so that the pressure-release lid is detached from the pressure-release port, and a protective cover that covers the pressure-release lid by providing a space outside the pressure-release lid is provided. A pressure relief device for a pole-mounted switch, wherein an external pressure relief port is formed in the protective lid to open obliquely upward. 2. The pole switch according to claim 1, wherein the fastening member is formed of a metal plate, the base of which is fixed to the upper plate, and the front end of which is engaged with a peripheral edge of the upper surface of the pressure release lid. Pressure relief device.