JPS6239522B2 - - Google Patents

Description

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

Recently, corrugated heat sinks with deep fin-like overhangs with closed upper and lower ends have been manufactured by bending thin steel plates, and tanks for electrical equipment such as transformers using these plates have been put into practical use. ing. FIG. 1 is a side view of a transformer having this type of tank, and FIG. 2 is a cross-sectional view taken along line X-X' of FIG. 1, showing a corner of a conventional tank. The side wall of the tank 1 shown in FIG. 1 is formed of a corrugated heat sink 2 having a large number of fin-like protrusions 3 whose upper and lower ends are closed, and a flange for attaching a tank cover 4 to the corrugated heat sink 2. The tank is constructed by welding the provided upper frame 5 and the lower frame 6 to which the tank bottom plate is attached.

Conventional tanks of this type include one in which the corrugated heat sink 2 is bent at the corner 7 as shown in Fig. 2a, and one in which the corrugated heat sink 2 is bent at the corner 7 as shown in Fig.
The corrugated heat sink 2 is welded at the corner 7 as shown in d, or the L-shaped reinforcing joint plate 8 is placed at the corner and the corrugated heat sink 2 is welded to this as shown in e. be.

This tank is filled with insulating oil to cool and insulate the electrical equipment, and depending on the application, it is sealed with a space for pressure adjustment, so when the equipment is in use, there is no insulating oil on the side wall of the tank. Static pressure from the head and dynamic pressure from the volumetric expansion of the internal air as the temperature rises act.

FIG. 3 shows how the fin-like projections of the corrugated heat sink in a conventional tank are deformed by these internal pressures. This deformation appears symmetrically as δ ₁ with respect to point A in the abdomens 3 _a on opposite sides of the adjacent fin-like overhangs 3, and the amount of deformation is relatively small. However, the abdomen 3 facing the corner side of the fin-like overhang 3 located near the corner of the tank
A larger deformation than δ ₁ occurs in _b , such as δ ₂ . For example, plate thickness t = 1.2 mm, depth of overhang (wave height) h = 315 mm, width of overhang (wave width) b = 10.4
mm, gap between overhangs (wave pitch) l ₁ = 37.5 mm, distance from tank corner to nearest overhang l ₂ = 50 mm, vertical length of overhang l ₃ = 1524 mm waveform When an internal pressure of 0.1 Kg/cm ² was applied to a tank using a heat sink, deformations of δ ₁ = 10 mm and δ ₂ = 20 mm were observed [this amount of deformation was the same for any of the structures shown in Figure 2 a to e]. There is no difference]. This deformation increases as the internal pressure increases, and eventually exceeds the elastic limit of the material and causes permanent deformation. Therefore, such δ
In a tank structure in which the amounts of deformation of _{δ 1} and δ ₂ are different, the allowable internal pressure, etc. must be determined based on the value of δ ₂ . If the amount of deformation of this overhang is δ ₂ ≒ δ
If the pressure can be reduced to ₁ , the tank will be able to withstand even greater internal pressure.

The reason why the amount of deformation of the overhang portion satisfies δ ₂ >δ ₁ can be explained as follows. As shown in FIG _. 4, when an internal pressure of p per unit area is applied to each part of the corrugated heat sink 2, M=p・_a (a: pressure receiving A force of area) is applied. Considering the moment around the center point A of the force M acting on the opposing abdomens 3 _a of adjacent fin-like overhangs 3, the moment of the force acting on these opposing abdomens 3 _a is abdomen 3 _a
exerts a force in the direction that reduces the force M. Therefore, the amount of deformation δ ₁ that occurs in the opposing abdomens 3 _a is symmetrical and relatively small, but the amount of deformation δ 1 that occurs in the abdomens 3 _a facing each other is symmetrical and relatively small. There is no force acting from the abdomen _3a facing M, and the force opposing M is from the abdomen 3 of the corrugated heat sink 2.
Since only the force N is applied to the pressure-receiving surface from _b to the tank corner 7, there is no balance as M>N, and as a result δ
It is considered that ₂ > δ ₁ . This tendency is more remarkable when the width b of the overhang is smaller than the depth h of the overhang. If the distance l ₂ from the tank corner to the nearest overhang is increased to the same extent as the depth h of the overhang, the amount of deformation δ ₂ will be reduced, but in order to do this, the number of overhangs 3 must be reduced. , the heat dissipation area must be sacrificed.

Furthermore, in the tank structure shown in FIGS. 2b to 2e,
When the depth h of the overhang 3 is increased, thermal distortion due to welding of the tank corner 7 will greatly appear on the abdomen 3 _b facing the corner side of the overhang 3 near the corner, and the commercial value will be impaired. Cheap. This is thought to be due to the fact that there is little room for welding heat to escape at the tank corners, and as a result of this thermal influence, the abdomens 3 _a and 3 _b on both sides of the overhang 3 near the tank corners become thermally unbalanced. .

The present invention has been made in view of the above points, and the first object is to provide a small and lightweight tank for electrical equipment that can withstand greater internal pressure without sacrificing the cooling effect. The purpose of this is to prevent thermal distortion of the corrugated heat sink due to welding heat at the tank corners.

In order to achieve the above object, the present invention forms a tank side wall by welding a corrugated heat dissipation plate having a large number of fin-like protrusions with closed upper and lower ends to a joint plate placed at the corner of the tank side wall. In what I did,
The joint plate is provided with a fin-like protrusion whose upper and lower ends are closed, and an extension that opens at right angles to each other from the base of the protrusion, and the side ends of the corrugated heat sink are welded to the extension. It is characterized by being configured as follows.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 5 is a partial sectional view of the tank of the present invention corresponding to the section taken along the line X-X' in FIG. 1, and FIG. 6 is a perspective view of this portion. Reference numeral 2 denotes a corrugated heat dissipation plate having a large number of fin-like protrusions 3. The upper and lower ends of the fin-like protrusions 3 are squeezed inward as shown in FIG. 6, and the end faces are closed with weld beads 9. Oil leakage has been stopped. Reference numeral 10 denotes a joint plate disposed at the corner of the tank side wall, and this joint plate 10 is made of a steel plate having the same width as the corrugated heat sink 2 and is formed into a deep U like the fin-like protruding portion 3 of the corrugated heat sink 2.
Bend it into a letter shape, squeeze the top and bottom ends inward,
Fin-shaped overhang 1 formed by closing with a weld bead 12
1, and extension portions 13 _a and 13 _b that open from the base of the fin-like overhang portion 11 in directions perpendicular to each other,
The extension parts 13 _a and 13 _b are joined to the side ends of the corrugated heat sink 2 by weld beads 14 _a and 14 _b , respectively, so that the fin-like projecting parts 11 protrude outward from the tank corners in an oil-tight manner. Make up the tank side walls of the structure. The fin-like projecting portion 11 is formed to have approximately the same dimensions as the fin-like projecting portion 3, and the distance from the tank corner to the nearest fin-like projecting portion 3 is determined by the distance between the projecting portions 3 (wave pitch). ).

When a tank configured in this manner is subjected to internal pressure, a force corresponding to M shown in FIG. Fin-shaped overhang 3
A force opposing M is generated on the abdomen 3 _b facing the corner side of . Similarly, the abdomen of the fin-like projecting part 11 is also covered with the abdomen 3 _b of the fin-like projecting part 3 facing this.
There is a force acting against it. As a result, almost symmetrical deformation occurs in the abdomens where the overhanging parts 3 and 11 face each other, and the amount of deformation δ ₂ is the amount of deformation δ caused in the abdomens 3 _a where the overhanging parts 3 face each other. ₁ or so (δ ₂ ≒
δ ₁ ), and the deformation of the abdomen 3 _b is significantly smaller than in the case where the overhanging portion 11 is not provided. This results in
The unbalanced amount of deformation that existed in the past is eliminated,
It becomes possible to obtain a tank that is harmonious in terms of strength.

In addition, the heat generated during welding of the joint plate 10 and the corrugated heat sink 2 is dispersed to the fin-like protrusions 3 and 11 on both sides.
Since extreme thermal imbalance does not occur between the flanks 3 _a and 3 _b on both sides of the fin-shaped projecting portion 3 near the tank corners, as in the conventional case, thermal distortion can also be prevented.

The joint plate 10 having the fin-like projections also increases the heat dissipation area of the tank by utilizing the dead space at the corners of the tank, helping to reduce the size and weight of the equipment.

As explained above, the present invention arranges a joint plate having a fin-like protruding portion with closed upper and lower ends at the corner of a tank side wall, and a corrugated heat sink is installed at a right angle extension of the joint plate. By welding the tank side wall, welding the corners of the tank side wall to the fin-like overhangs of the corrugated heat sink near the corners, as in tanks for electrical equipment using conventional corrugated heat sinks. A small and lightweight electrical device that can prevent large thermal distortions from occurring and damage the product value, has balanced strength, and can withstand greater internal pressure without being restricted by the depth or number of fin-like protrusions. tank can be provided.

[Brief explanation of the drawing]

Figure 1 is a side view of an electrical device using a corrugated heat sink on the side wall of the tank, Figure 2 is a partial cross-sectional view of a conventional tank taken along the line X-X' in Figure 1, and Figure 3 is a side view of a conventional tank. FIG. 4 is an explanatory diagram showing the deformation state of the fin-like protrusion due to internal pressure. FIG. 4 is an explanatory diagram of the action of the force that causes the deformation in FIG. 3. FIG. 5 is a diagram showing the tank of the present invention in FIG. 6 is a perspective view of this portion. DESCRIPTION OF SYMBOLS 1...tank, 2...corrugated heat sink, 3...fin-like protrusion of corrugated heat sink 2, 9...fin-like protrusion 3
weld bead, 10... joint plate, 11... joint plate 10
12... welding bead of the fin-like protrusion 11, 13 _a , 13 _b ... extension of the joint plate 10,
14 _a , 14 _b ... Weld beads that join the joint plate 10 and the corrugated heat sink 2 .

Claims (1)

[Claims] 1 In a tank side wall formed by welding a corrugated heat dissipation plate having a large number of fin-like protrusions with closed upper and lower ends to joint plates placed at the corners of the tank side wall, A fin-like overhang with a closed end and an extension that opens at right angles to each other from the base of the overhang are provided, and the side ends of the corrugated heat sink are welded to the extension. A tank for electrical equipment featuring: