JPH0451456Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a pressure relief device used in oil-immersed electrical equipment such as oil-immersed transformers.

[Prior Art] Oil-filled electrical equipment in which the main body of the electrical equipment is housed together with insulating oil in a tank is provided with a pressure relief device to prevent the pressure in the tank from becoming excessive.

4 and 5 show conventional pressure relief devices for oil-filled electrical equipment. a pressure relief pipe 4, a second pressure relief pipe 5 whose one end is connected to the first pressure relief pipe 4, a pressure relief plate 6 disposed between the first and second pressure relief pipes, and a second pressure relief pipe 4; It includes a tip flange 7 provided on the other end side of the pressure pipe 5, and an oil guide tube 9 whose one end abuts against the tip flange 7 via a packing 8. Patsukin 8 is
It integrally includes an annular packing main part 8a that is sandwiched between the other end of the tip flange 7 and one end of the oil guide pipe 9, and an annular oil guide pipe fitting part 8b that is fitted to the outer periphery near one end of the oil guide pipe. are doing. Oil guide pipe 9 is connected to tank 2
The oil guide pipe 9 is arranged so as to extend vertically on the side thereof and is fixed to the side wall of the tank 2 by a mounting bracket 10, and the lower end of the oil guide pipe 9 is inserted into an oil reservoir pit 12 provided under the floor 11. has been done.

In the pressure relief device 1 described above, when an accident occurs in the tank 2 of an electrical device and the pressure inside the tank increases, the pressure relief plate 6 breaks and releases the pressure inside the tank. At this time, a large amount of insulating oil is released outside the tank, so an oil guide pipe 9 is provided to prevent the insulating oil from scattering around.

[Problems to be Solved by the Invention] In the above pressure relief device, the pressure relief plate is destroyed during the pressure relief operation, so it is necessary to replace the pressure relief plate after the pressure relief operation is performed. Furthermore, even if the pressure relief operation is not performed, it is necessary to periodically inspect the vicinity of the pressure relief plate for cracks, oil leaks, etc.

In order to facilitate replacement of the pressure relief plate and periodic inspection work around the pressure relief plate, a gasket 8 is attached to one end of the oil guide pipe 9 instead of connecting the oil guide pipe 9 and the tip flange 7 with bolts as described above. A structure is adopted in which the oil guide pipe 9 and the tip flange 7 are brought into contact with each other through the packing.

In this way, the conventional pressure relief device adopts a structure in which one end of the oil guide pipe 9 simply butts against the tip flange 7 via the packing 8.
Oil sometimes leaked from the butt portion between the end flange 7 and the end flange 7. To prevent this oil leak,
It is conceivable to increase the force that presses the gasket 8 against the tip flange 7, but in the conventional pressure relief device, the gasket was simply fitted and held at one end of the oil guiding pipe 9, so the gasket was pushed against the tip flange 7. There was a problem in that when the force applied to the sides was increased, the gaskets were more likely to fall off.

The purpose of this invention is to provide a pressure relief device for oil-filled electrical equipment that is capable of firmly sealing the butt connection between the oil guiding pipe and the tip flange by strongly pressing the packing against the tip flange without causing the packing to fall off. Our goal is to provide the following.

[Means for Solving the Problems] The present invention includes a first pressure relief pipe connected to a tank of oil-filled electrical equipment via an attachment pipe, and a second pressure relief pipe connected at one end to the first pressure relief pipe. A pressure relief pipe, a pressure relief plate disposed between the first and second pressure relief pipes, a tip flange provided on the other end side of the second pressure relief tube, and one end abutting the tip flange through a packing. In the pressure relief device for oil-filled electrical equipment, which is equipped with an oil guiding pipe, there is no fear that the packing will fall off even if the force for pressing the packing against the tip flange side is increased.

Therefore, in the present invention, a packing receiving plate for receiving the packing from the axial direction is provided at a position adjacent to the packing on the outer periphery near one end of the oil guiding pipe. Further, a packing tightening band was provided to abut on the outer peripheral surface of the packing and tighten the packing, and the packing was tightened and restrained by the packing tightening band.

[Operation of the invention] As described above, by providing a packing receiving plate and a packing tightening band to restrain the packing, the risk of the packing falling off can be eliminated, so the force that presses the packing against the tip flange side can be reduced. can be strengthened to reliably prevent oil leakage.

[Embodiments] Examples of the present invention will be described below with reference to the accompanying drawings.

Figures 1 to 3 show an embodiment of the present invention. Figure 1 shows the structure of the main part of the embodiment of the present invention, and Figure 2 is a top view of a half of Figure 1. . Further, FIG. 3 shows a tightening band used in the same embodiment.

In FIG. 1, the first pressure relief pipe 4 and the second pressure relief pipe 5 have flanges 4a and 5a at their respective ends.
, and a pressure relief plate 6 is sandwiched between these flanges. Annular gaskets 20 and 21 are inserted between the pressure relief plate 6 and the flange 4a and between the pressure relief plate 6 and the flange 5a, respectively.

A ring-shaped tip flange 7 is in contact with the other end of the second pressure relief pipe 5 . A shallow groove 7a is provided around the tip flange 7, and a shallow groove 7a is provided in the groove to provide a fluid-tight joint between the two. An annular packing 22 is inserted.

Flanges 4a and 5a each have 8 bolt insertion holes 4b, 4b, 4b, 4b,
... and 5b, 5b, ... are provided, and the tip flange 7 is provided with four bolt insertion holes 7b equally spaced (at angular intervals of 90 degrees). A cylindrical protrusion 7c is provided on the inner circumference of the tip flange 7 and protrudes on both sides in the axial direction, and the protrusion serves as a packing holder.

The four bolt insertion holes of the tip flange 7 are aligned with the four bolt insertion holes of the flanges 4a and 5a, respectively, and the long bolts 23, 23, . . . are inserted through these aligned holes. Nuts 24, 25 and 26 are screwed into each bolt 23, and these bolts and nuts tighten the flange 4.
a, 5a are mutually tightened and connected, and the tip flange 7 is fixed to the second pressure relief pipe 5 in a state where it is urged toward the second pressure relief pipe 5 side. Further, short bolts 27 are inserted into other bolt insertion holes provided in the flanges 4a and 5a, and nuts 28 are inserted into the bolts.
are screwed together, and the flanges 4a and 5b are connected by these bolts and nuts.

The first and second pressure relief pipes 4 and 5 and the pressure relief pipe 6
A pressure relief portion is constituted by a portion including the tip flange 7 and the tip flange 7. The first pressure relief pipe 4 of this pressure relief section is usually equipped with a needle that is driven by a pressure response mechanism such as a pressure relief valve, and the needle destroys the pressure relief plate when the pressure inside the tank of the electrical equipment rises abnormally. Although a mechanism is provided, illustration of this mechanism is omitted.

The oil guide pipe 9 is attached to the tank of the electrical equipment using a mounting fitting as in the example shown in FIG. 4, and its lower end is inserted into a pit for an oil sump under the floor. A gasket 8 made of rubber, sponge, etc. is fitted onto the upper end of the oil guide pipe 9. This packing 8 integrally includes an annular packing main portion 8a sandwiched between the tip flange 7 and one end of the oil guide pipe 9, and an annular oil guide pipe fitting portion 8b connected to the packing main portion. There is. The oil guide pipe fitting part 8b has a thinner wall thickness than the packing main part 8a, and is formed near the outer periphery of the packing main part 8a, so that the outer circumferential surface of the main part 8a of the packing 8 and the outer periphery of the oil guide pipe fitting part 8b The surface is flush with the surface. This packing is the fitting part 8
b is held in a state where it is fitted onto the outer periphery of the upper end portion of the oil guiding pipe 9. The oil guiding pipe 9 is positioned so as to hold the gasket 8 pressed against the lower surface of the tip flange 7 with a predetermined pressing force, and is fixed to the tank of the electrical equipment. In order to position the oil guide pipe 9, the vertical position of the oil guide pipe 9 can be adjusted as appropriate. For example, when using a mounting bracket 10 having a structure in which a mounting bracket 10a provided on the oil guide pipe 9 side is fixed to a mounting bracket 10b provided on the tank side with a bolt 10c as shown in FIG. 4, the bolt 10c is inserted. Mounting bracket 1
One of the holes provided in each of 0a and 10b is made into a long hole that is long in the vertical direction.

An annular packing receiving plate 29 is welded to the outer circumference near one end (in this example, the upper end) of the oil guide pipe 9, and this packing receiving plate 29 abuts against the end surface of the packing 8 to align the packing 8 with the axis. I've learned to accept things from different directions. Reference numeral 30 denotes a reinforcing rib welded to the outer periphery of the oil guide pipe 9 in order to reinforce the seal receiving plate 29.

After the oil guide pipe 9 is positioned and fixed to the tank as described above, the packing tightening band 31 is arranged so as to surround the packing 8. As shown in FIG.
Two semicircular arc-shaped half parts 31A and 31 having b
B, and one end of half part 31A and one end of half part 31B opposite to the other end of half part 31A, respectively.
Covering plate 3 spanning between both halves and covering the gap between both halves
1A ₁ and 31B ₁ are welded.

Opposing protrusions 31a, 31 of the tightening band
b are provided with bolt insertion holes that align with each other, and bolts 32 are inserted into the bolt insertion holes of both protrusions. A nut 33 and a lock nut 34 are screwed into the bolt 32, and these bolts and nuts bias the half portions 31A and 31B toward each other. As a result, the gasket 8 is restrained in a radially inwardly tightened state.

As described above, when the packing 8 is pressed against the tip flange 7 and the packing 8 is tightened by the tightening band 31, the packing 8
Since the seal 8 is restrained by the seal receiving plate 29, the seal will not fall off even if the seal 8 is strongly pressed against the tip flange 7.

Note that when the packing 8 is strongly pressed against the tip flange 7 and the tightening band 31 is used to tighten the packing, the inner circumferential portion of the packing main part 8a bulges inward as shown in the figure. When the protrusion 7c is provided on the inner circumference of the tip flange 7, the protrusion 7c acts as a seal presser and presses the seal 8 from inside, thereby preventing the seal 8 from escaping inward.

In the pressure relief device described above, when replacing the pressure relief plate 6, loosen the bolts tightening the oil guide pipe mounting bracket, lower the oil guide pipe 9 slightly downward, and then tighten the bolts 23.
and remove the tip flange 7. Next, the second pressure relief pipe 5 is removed and the pressure relief plate 6 is replaced. The same applies when inspecting the area around the pressure relief plate.

When connecting the oil guide pipe after replacing the pressure relief plate 6, first attach the tip flange 7, then push up the oil guide pipe 9, press the packing 8 to the tip flange, and tighten the bolts of the fitting for the oil guide pipe 9.

In the above embodiment, the first and second pressure relief pipes 4 and 5 and the oil guide pipe 9 are arranged vertically, but the first
and a second pressure relief pipe are arranged horizontally, and the oil guide pipe 9
The present invention can be similarly applied to the case where a part of the frame is arranged horizontally.

[Effects of the invention] As described above, according to the present invention, a packing receiving plate is provided on the oil guide pipe and a packing tightening band is provided to restrain the packing, thereby eliminating the risk of the packing falling off. This has the advantage of increasing the force that presses the gasket against the tip flange to reliably prevent oil leakage.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the main part showing an embodiment of the present invention, Fig. 2 is a top view of half of Fig. 1, Fig. 3 is a top view of the packing tightening band used in the same embodiment, and Fig. 4 is a conventional one. FIG. 5 is a front view showing the overall structure of the conventional pressure relief device, and FIG. 5 is a sectional view showing the structure of the main parts of the conventional pressure relief device. 1... Pressure relief device, 2... Tank for electrical equipment, 3
...Mounting pipe, 4...First pressure relief pipe, 5...Second
pressure relief pipe, 6... pressure relief plate, 7... tip flange,
8...Patsukin, 8a...Patsukin main part, 8b...
...Oil guide pipe fitting part, 9...Oil guide pipe, 10...Oil guide pipe mounting bracket, 29...Packskin receiving plate, 31...
Patchkin tightening band.

Claims (1)

[Claims for Utility Model Registration] A first pressure relief pipe connected to a tank of oil-filled electrical equipment via an attachment pipe, a second pressure relief pipe whose one end is connected to the first pressure relief pipe, and the 1st and 2nd
a pressure relief plate disposed between the pressure relief pipes, a tip flange provided on the other end side of the second pressure relief tube, and an oil guiding pipe whose one end abuts against the tip flange via a packing. , the packing integrally includes an annular packing main part sandwiched between the tip flange and one end of the oil guiding pipe, and an annular oil guiding pipe fitting part fitted to an outer periphery of one end of the oil guiding pipe. A pressure relief device for oil-filled electrical equipment includes: a packing receiving plate fixed at a position adjacent to the packing on the outer periphery near one end of the oil guiding pipe to receive the packing from the axial direction; and an outer periphery of the packing. 1. A pressure relief device for oil-filled electrical equipment, comprising a packing tightening band that tightens and restrains the packing by coming into contact with a surface.