JPS5829608B2 - Tank for electrical equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a tank for electrical equipment using a corrugated heat sink with good cooling effect as a side plate of the tank.

BACKGROUND ART In electrical equipment such as oil-immersed transformers, attempts have been made to make tanks thinner in order to reduce the weight of the equipment and save resources.

However, as the plate thickness becomes thinner, the tank deforms due to the increase in internal pressure under load, causing problems in terms of strength.
The above-mentioned problems also limit the ability to reduce the thickness of the plate.

Recently, in order to reduce the size and weight of transformer tanks, etc., corrugated heat sinks are used as tank side plates, which are made by bending thin steel plates and have deep fin-like overhangs. Tank structures with welded frames have been put into practical use, but this type of tank structure poses a problem of deformation of the upper and lower frame members, which have lower rigidity than corrugated heat sinks.

Next, this problem will be explained using drawings.

Figure 1 is a side view of a transformer tank using a conventional corrugated heat sink, Figure 2 is a diagram showing the state of deformation when this tank receives internal pressure, and Figure 3 is a diagram showing the deformation that occurs near the welded part of this tank. It is an explanatory view of stress.

The corrugated heat dissipating plate 1, which becomes the side plate of the tank, is bent as described above to form a large number of fin-like protruding parts 2, and the upper and lower ends of each protruding part 2 are squeezed inward as shown in FIG. It is welded along the end face, and the flange 3 is attached to this corrugated heat sink 1.
The tank is constructed by welding the respective side parts 4/5' of the tank upper frame 4 and the tank lower frame 5 to which the bottom plate 6 is attached.

In Figure 3, 7 is the weld bead of the overhang 2, and 8 is the corrugated heat sink 1.
This is a weld bead that joins the tank upper frame 4 to the tank upper frame 4.

As shown in Figure 2, when internal pressure P is applied to this tank,
A highly rigid corrugated heat sink 1 having a large number of fin-like protrusions 2
moves outward as a whole, and as a result, a rotational force F acts on the side surfaces 4' and 5' of the upper and lower frames 4 and 5, and the side surfaces 4' and 5', which have relatively low rigidity, are rotated at two points by this rotational force F. It transforms as shown by the chain line.

atbse in FIG. 3 indicates the direction of stress acting on the weld bead 8 at this time. Particularly high stress occurs in the a direction, so a crack occurs in the weld bead 8 near the root of the overhang 2. , which can easily cause oil leaks.

Although FIG. 3 shows the welded portion between the corrugated heat sink 1 and the tank upper frame 4, the same applies to the welded portion between the corrugated heat sink 1 and the tank lower frame 5.

The present invention aims to provide a tank for electrical equipment of this kind that can alleviate the concentrated stress in the welded part due to the above-mentioned internal pressure and increase the allowable internal pressure without increasing the plate thickness. .

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 is a side view of a tank according to the present invention, FIG. 5 is a side vertical sectional view of this tank, FIG. 6 is an enlarged view of section A in FIG. 5, and FIG. 7 is taken along the line B-B in FIG. 5. FIG.

The example shown is a tank for a transformer, in which a corrugated heat sink 1 having a large number of fin-like protrusions 2 with closed upper and lower ends is used as the tank side plate, and a tank upper frame having a flange 3 on the corrugated heat sink 1. 4 and a tank lower frame 5 to which a bottom plate 6 is attached are welded together.

The above configuration is the same as the conventional one.

The gist of the present invention is that the valley side portions 4' and 5' of the tank upper frame 4 and the tank lower frame 5 are connected by a reinforcing bar 9 passed between the fin-like overhangs 2 of the corrugated heat sink 1. be.

In order to attach the reinforcing bar 9, each side part 4/, 5'
A backing plate 10 is welded to the backing plate 10, and a reinforcing bar 9 is welded to this backing plate 1°0.

The thickness of the contact plate 10 is made larger than the height h of the weld bead 8 that joins the corrugated heat sink 1 and the upper and lower tank frames 4 and 5, so that the reinforcing bar 9 straddles the weld bead 8.

By attaching an appropriate number of such reinforcing bars 9 to each side of the tank, when the tank is subjected to internal pressure, tensile stress is generated in the reinforcing bars 9 against the rotational force F shown in FIG. ', 5' deformation is suppressed.

As a result, the stress near the weld bead 8, fi = Fig. 3a
The stress in the direction is reduced, and cracking of the weld bead 8 can be effectively prevented.

Figure 4 shows an example in which two reinforcing bars 8 are attached to one side of the tank, and it has been confirmed that this reduces the stress near the weld bead 8 to less than 1/2 compared to when there are no reinforcing bars. It was done.

When the rotational force F is applied to the side surfaces 4' and 5', the reinforcing bar 9 receives a bending moment, so the contact plate 1
It is preferable to mount the reinforcing bar so that the long side of the cross section is perpendicular to the mounting surface of 0, so that the moment of inertia of the cross section is set to 0.

In addition, a hook hole 9' is provided at the top of the reinforcing bar 9 as a hook for lifting the tank, and when a hook (not shown) is hooked into this hole 9' when lifting the tank, the dead weight of the tank is applied to the reinforcing bar 9. Since the stress is applied to the lower frame 5 through the lifting member, the stress applied to the welded portions between the corrugated heat sink 1 and the upper and lower frames 4°5 due to lifting becomes extremely small, and as a result, damage to these welded portions can be prevented.

Further, the hook portion may be a hook-shaped projection.

As explained above, the present invention significantly increases the rigidity of the tank upper and lower frames, which was a weak point of conventional tanks of this type, by connecting the side parts of the tank upper and lower frames welded to the corrugated heat sink with reinforcing bars. This is effective in increasing the deformation resistance of the tank upper and lower frames against internal pressure and preventing damage to the welded parts due to deformation, and it is possible to maintain a sufficiently high tank allowable internal pressure even when the tank upper and lower frames are made thinner. Can be done.

Therefore, there is an effect that the tank can be further reduced in size and weight.

[Brief explanation of drawings]

Figure 1 is a side view of a tank using a conventional corrugated heat sink, Figure 2 is a vertical cross-sectional view showing the state of deformation that occurs when this tank is subjected to internal pressure, and Figure 3 is a side view of a tank using a conventional corrugated heat sink. 4 is a side view of the tank according to the present invention, FIG. 5 is a side vertical sectional view of this tank, and FIG. 6 is A of FIG. 5.
FIG. 7 is an enlarged view of the section, and is a cutaway plan view taken along line B--B in FIG. 5. 1... Corrugated heat sink, 2... Fin-shaped overhang, 4... Tank upper frame, 4'...
Same side part, 5... Tank lower frame, 5/...
...Same side part, 7, 8...Weld bead, 9...
...Reinforcement bar 9/ ...Hook part for lifting,
10...This board.

Claims (1)

[Claims] 1. A tank for electrical equipment that is fitted with a tank upper frame, a tank lower frame, and a corrugated heat sink having a large number of closed fin-like protrusions at the upper and lower ends provided as tank side plates. Upper tank frame, lower tank frame, and tongue? The space between the IUIJ plates is fixed by welding, and a latch is provided on each side of the tank upper frame and the tank lower frame.
Connect each side part of the tank upper frame and tank lower frame by welding with a multi-chord bar passed between the fin-shaped overhangs of the corrugated heat sink through a backing plate having a thickness equal to or greater than the bead of the welding part. A tank for electrical equipment that is characterized by: