JPS6328488B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a method of manufacturing a tank for oil-filled electrical equipment.

Technical Background of the Invention Generally, in oil-filled electrical equipment, heat generated inside the equipment is radiated from the surface of a tank using insulating oil as a medium. For this reason, the tanks of oil-filled electrical equipment are designed to enhance the heat dissipation effect.

Methods for increasing the heat dissipation effect from the tank surface include attaching heat dissipation fins to the tank side plates, attaching heat dissipation pipes that communicate with the inside of the tank at the top and bottom ends of the tank side plates, and seam welding the outer periphery of two panel plates. A method in which a plurality of panel elements manufactured by the manufacturer are combined and headers are provided above and below the panel elements is attached to the tank side plate, or a method in which the heat dissipation area is increased by forming hollow heat dissipation fins on the tank side plate that communicate with the inside of the tank. etc., but recently the latter two have been mainly adopted.

FIG. 1 shows a conventional tank side plate 1 having the hollow heat dissipating fins.
In this method, a thin strip-shaped steel plate is bent at regular intervals by a wave-forming press process to form a corrugated plate 2 in which a large number of fin portions 1a having a cross-sectional shape as shown in FIG. As shown in FIG. 3, they are pressed together and welded, and reinforcing connecting members 3 are welded to each fin portion 1a.
In addition, each fin portion 1a has a large number of depressions or recesses 4.
are formed by press working at symmetrical positions on the opposing wall surface forming each fin portion 1a, and this recess 4
By bringing the bottom surfaces of the fins into contact with each other, the fin portion 1
I try to keep the inside of a hollow.

Fig. 4 shows a tank for oil-filled electrical equipment using the tank side plate 1, and this tank has an upper and lower edge of the tank side plate 1 as a tank upper edge frame 5, and a tank bottom that also serves as the tank bottom plate. It is manufactured by welding to the edge frame 6.

On the other hand, in order to ensure insulation performance, oil-filled electrical equipment is generally dried in advance to remove moisture and then vacuum lubricated to completely impregnate the insulator with oil. For this vacuum lubrication method,
There are two methods: one is to place the tank in a vacuum container and lubricate in a vacuum atmosphere, and the other is to lubricate at atmospheric pressure with the tank inside a vacuum. If the capacity of the transformer is large, use the former method. Since this requires a large-volume vacuum container, the latter method is often adopted. However, in the case of the tank in which the fin portion is formed by bending the tank side plate, the thickness of the tank side plate is thin, so if the tank is filled with oil by the latter method, if the recessed part 4, there is a risk that when the inside of the tank is evacuated, the walls on both sides of the fin portion 1a will not be able to withstand the pressure difference between the inside and outside, and will be recessed and deformed, causing the hollow portion of the fin to collapse. Furthermore, in oil-filled electrical equipment, the internal pressure of the tank increases due to the expansion of the insulating oil, which rises in temperature as the equipment generates heat.
The side plates a cannot withstand the internal pressure of the tank and bulge and deform, resulting in an increase in the internal volume of the tank and a drop in the oil level.

Therefore, in a tank in which a hollow fin portion is formed by bending the tank side plate, it is necessary to reinforce the fin portion, and the recess 4 is formed for this purpose. The recess 4 shown in FIGS. 1 to 4 is a reinforcing recess formed on both side plates of the fin portion to reinforce the fin portion 1a, and the recess 4 is, for example, circular. There is. The recesses 4 are abutted against each other in the fin portion 1a as shown in FIGS. 2 and 3, and support both side plates of the fin portion from the inside to prevent the recessed deformation thereof. Further, the concave portions 4 on both sides are spot welded at their abutting portions to connect the side plates of the fin portion and prevent expansion deformation thereof.

Background Problems of the Prior Art By the way, in oil-filled electrical equipment tanks in which hollow heat dissipation fins are formed by bending the tank side plates, in order to increase the amount of heat dissipation, it is necessary to increase the overhang length of the fins. is necessary. However, in the method of continuously forming hollow heat dissipating fins, there is a limit to the overhanging length of the fin portion 1a due to manufacturing constraints.

Moreover, conventionally, after forming the fin part by bending the tank side plate, the reinforcing recess 4 is worked and the side plates of the fin part are spot welded, but the press working and spot welding of this recess are done by pressing the adjacent fin part 1a. Since it has to be carried out within the space between them, machining and spot welding of the recesses 4 takes time and effort, and for this reason, the conventional method has extremely poor workability in manufacturing tanks.

Purpose of the Invention The present invention has been made in view of the above circumstances, and its purpose is to improve the work efficiency of a tank for oil-filled electrical equipment having a structure in which a hollow heat dissipating fin portion communicating with the inside of the tank is formed on the side plate of the tank. To provide a method for manufacturing a tank for oil-filled electrical equipment, which can be manufactured well, and can also make it possible to increase the projecting length of a fin part, and can obtain a tank with high heat dissipation effect.

Summary of the Invention In other words, in order to achieve the above-mentioned object, the present invention first press-works a thin steel plate to form a pair of flanges that stand up on one side at a pair of opposing edges. After making a hollow fin part by folding the panel board in half so that the flange part is on the outside and both flanges face each other, a required number of metal parts are placed at arbitrary locations inside the hollow fin part. The spacer pieces are each fixed to the thin steel plate forming the hollow fin section by spot welding, etc., and the open side edges of the fin section are welded to form a panel element, and a plurality of these panel elements are used to form a flange section. The tank side plates are assembled by placing them side by side and connecting the flange parts by welding, and by folding the panel plate in half to form the fin part, it is possible to assemble the tank side plate. Compared to the method of continuously forming hollow fins by sequentially bending a single thin steel plate, it is possible to increase the overhang length of the fins, and therefore the heat dissipation area of the tank side plate is increased. It is possible to obtain a tank with a large amount of heat, and by spot welding the metal spacing piece and the side panels of the fin section to strengthen the fin section before assembling the tank side panels, these operations can be easily carried out. It is possible to manufacture tanks easily and with good workability.

Embodiments of the Invention An embodiment of the method of the present invention will be described in detail below with reference to the drawings.

(Process 1) First, a thin steel plate of a predetermined size is press-formed, and the fifth
A panel board 10 as shown in FIGS. 7 to 7 is manufactured. This panel board 10 has flange parts 13 on both side edges rising toward the front surface, and has edge parts 10a on both end edges of this flat plate part that are rolled down and stepped toward the back surface side over the entire length thereof. Shaped by press working. 6 is a cross-sectional view of FIG. 5, FIG. 7 is a cross-sectional view of FIG. 5, and OO is a center line.

(Step 2) With the front side of the panel board facing outward, align the center line O.
-A hollow fin portion 11a is formed by folding in half from O as shown in FIG. At this time, the surfaces of both end edges 10a of both side plates of the fin portion, which are provided symmetrically with respect to the center line OO, are in contact with each other.

(Step 3) Fin hollow part (inside) formed in the above step
A necessary number of metal linear band-shaped spacing pieces 12 are inserted at appropriate intervals so that their longitudinal direction is parallel to the center line O-O, and they are spot welded together with both side plates of the fin portion at predetermined intervals. and fix it. Figure 9 shows this spot welding process.
indicates a spot weld. 15 is a welding electrode.

(Step 4) Next, both end edges of both side plates of the fin portion are welded. Any welding method that seals the hollow part of the fin can be used for this welding, but MAG (metal arc,
Ideally, gas welding is used. Figure 10 shows the welding process, where 16 is the welded part, 1
7 is a welding torch, 18 is a manipulator that holds and moves this welding torch 17 to perform welding, 19
is a support stand for supporting the workpiece. In this embodiment, both end edges of the fin are pressed down to the back side of the panel (inside the fin) in the state of the panel board 10, so there is no need to press the end edges of the fin into contact during welding.

Through the above steps, a panel element 11 consisting of a hollow fin portion 11a with only the base open and flange portions 13 on both sides of the base is manufactured, and then a tank side plate is manufactured through the following steps.

(Step 5) Since the outer edge of the flange portion of the panel element 11 has been deformed to some extent due to the press working in the manufacturing process of the panel plate 10, in order to minimize the gap during welding of the panel elements in the next step, we Next, press cut the outer edge of the flange to straighten it. FIG. 11 shows this cutting process. In the figure, 20 is an upper mold, 21 is a lower mold, and 22 is a holder for holding this lower mold.

(Step 6) Next, a large number of panel elements 11 are sequentially joined together by butt welding the flange portions 13 to form a tank side plate. FIG. 12 shows this panel element connection welding process. In the figure, reference numeral 23 denotes a butt weld, 24 a presser metal fitting for pressing the flange portion 13 of the panel element 11, and 25 a welding torch that forms a pair with the presser metal fitting 24 to sandwich the flange portion 13.

(Step 7) A reinforcing connecting material 27 is attached to the tip of the fin portion 11a of each panel element connected and welded in this way.
to weld. FIG. 13 shows this reinforcing connection material welding process. In the figure, 28 is a holding jig, and 29 is a welding torch. While holding down the fin portion 11a of the panel element with the holding jig 29, the reinforcing connecting member 27 is welded to the tip of the fin portion 11a with the welding torch 29.

14 to 17 show an oil-filled electrical equipment tank using the tank side plate manufactured as described above, FIG. 14 is a plan view, and FIG. 15 is a first
Figure 4 is a sectional view, Figure 16 is a cross-sectional view of Figure 15.
17 shows a cross-sectional view of the fin portion 11. As shown in FIG. In the figure, 30 is a vertical reinforcing beam made of metal with an H-shaped cross section, 31 is a tank upper edge frame, 32 is a tank lower edge frame which also serves as a tank bottom plate, 33 is a cover, and 34 is a bushing provided on the cover. These 3
0, 31, and 32 are assembled into an airtight structure by welding.

As described above, in this manufacturing method, the hollow fin portion 11a is formed by folding the panel plate 10, which is a press-formed steel plate, into two, and even when the panel plate 10 is made larger, the bending of the panel plate 10 is still possible. Since it is easy to perform, it is possible to form a fin portion with a large overhang length, which was impossible with conventional manufacturing methods, and it is therefore possible to create a tank with a large amount of heat dissipation by further increasing the heat dissipation area of the tank side plate. Obtainable. Moreover, in this manufacturing method, spot welding between the side plates of the fin part and the metal spacing piece in the hollow part of the fin can be easily performed without the presence of adjacent fin parts, and furthermore, panel element interconnection welding can also be performed on the flange 13. Since the welding torch 26 can be simply moved linearly along the butt portion, the tank can be manufactured with good workability.

The arrangement of the metal spacing pieces inside the hollow fin section is such that when used as a tank for oil-filled electrical equipment,
It is sufficient that the flow of oil filled inside the fin hollow portion is not obstructed, and the present invention is not limited to those of the above-mentioned embodiments.

FIG. 18 shows an embodiment in which instead of the linear band-shaped spacing piece 12, an appropriate number of spacing pieces 35 formed by bending a band-shaped metal not in a straight line but in a U-shape, for example, are arranged. , FIG. 20 shows a disc-shaped spacing piece 36 and a rectangular flat plate spacing piece 37 arranged in a grid pattern.

Furthermore, even in this arrangement, the arrangement may be arranged in a staggered manner instead of in a grid pattern. Even if you do this, the same effect can be obtained.

The cross-sectional shapes of the metal spacing pieces are shown in Figures 21 a to d.
As shown at 38 to 41, it can be formed not only in a simple rectangular shape but also in a hollow rectangular shape 38, an elliptical shape 39, a hollow elliptical shape 40, or a U-shape 41.

Since the method for manufacturing an oil-filled electrical equipment tank of the present invention is as described above, it is possible to easily manufacture an oil-filled electrical equipment tank having a structure in which a hollow heat dissipating fin portion communicating with the inside of the tank is formed on the side plate of the tank. It is possible to manufacture a tank with a large amount of heat dissipation because it is possible to increase the overhang length of the fin portion.

Effects of the Invention As detailed above, the method for manufacturing an oil-filled electrical equipment tank of the present invention involves press-working a thin steel plate, and forming a pair of flange portions rising up on one surface side on a pair of opposing edges. After making a panel board and folding the panel board in half so that the flange part is on the outside and both flanges face each other to form a hollow fin part, a desired place is placed inside the hollow fin part. Several metal spacing pieces are each fixed to the thin steel plate forming the hollow fin part by spot welding, etc., and the open side edges of the fin part are welded to form a panel element. The tank side plate is assembled by connecting the flange parts by welding, and by folding the panel plate in half to form the fin part. Compared to the conventional method of sequentially bending a single thin steel plate and continuously forming hollow fins, it is possible to increase the overhang length of the fins, thus reducing the heat dissipation area of the tank side plate. In other words, it is possible to obtain a tank with a large amount of heat dissipation, and in order to strengthen the fin part, the metal spacing piece and the side plates of the fin part are fixed by spot welding etc. before assembling the tank side plates. ,
These operations can be carried out easily, and therefore tanks can be manufactured with good workability.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a tank side plate manufactured by a conventional method, Figs. 2 and 3 are enlarged perspective views taken along lines AA and B-B in Fig. 1, and Fig. 4 is a perspective view of a tank side plate manufactured by a conventional method. A perspective view of a tank using the tank side plate shown in Figure 1, No. 5
Figures to Figure 17 show one embodiment of the present invention.
Figure 5 is a perspective view of a panel plate manufactured by pressing a thin steel plate, a sectional view taken along the lines - and - in Figures 6 and 7, and Figure 8 is a view of the panel plate folded in half. FIG. 9 is a perspective view of the process of spot welding the metal spacing piece in the hollow fin and the side plates of the fin, FIG. 10 is a perspective view of the process of welding both edges of the side plates of the fin, and FIG. 12 is a perspective view of the panel element connection welding process; FIG. 13 is a perspective view of the reinforcing connection material welding process; FIG. 14 is a plan view of the manufactured tank; FIG. 16 is an enlarged view of a portion of FIG. 14; FIG. 17 is an enlarged sectional view taken along line - in FIG. 15;
18 to 20 are views showing other embodiments of the arrangement of the metal spacer pieces, and FIG. 21 is a view showing another example of the cross-sectional shape of the spacer pieces. 10... Panel board, 11... Panel element, 11a... Fin portion, 12, 35, 36, 3
7, 38, 39, 40, 41... spacing piece, 13...
...Flange part, 14...Spot weld part, 17...
...MAG weld, 23...butt weld.

Claims (1)

[Claims] 1 Press a thin steel plate to form flange parts on each of a pair of opposing edges to make a panel plate, and make the flange part of this panel plate on the outside,
After the panel board is folded in half so that the pair of flanges face each other to form a hollow fin, a metal spacing piece disposed inside the hollow fin is inserted into the fin from the outside of the hollow fin. Welding and welding the open side edge portions of the fin portions to form a panel element, and arranging a plurality of panel elements in parallel with their flange portions adjacent to each other,
A method of manufacturing a tank for oil-filled electrical equipment, characterized in that a tank side plate is formed by welding and connecting adjacent flange parts.