JPH0139642B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a tank for oil-filled electrical equipment such as a transformer or a reactor, and particularly relates to a tank for oil-filled electrical equipment with improved mechanical strength. be.

[Technical background of the invention and its problems]

Generally, when insulating oil is injected into a tank that houses the electrical equipment in oil-filled electrical equipment such as high-voltage transformers and reactors, external pressure is applied to the side wall of the tank to create a vacuum inside the tank.
The tank itself must have the mechanical strength to withstand this. In addition, large-capacity transformers have large accidental currents during operation, and the tank must have sufficient internal pressure strength to prevent oil decomposition due to heat, explosions, etc.

Figures 1a and 1b are diagrams showing a deformed state when the tank is evacuated during oil filling. In the case of a large-capacity transformer, abnormalities in the main body of the electrical equipment are checked after various routine tests at the factory, and the top cover 1 of the tank is replaced with a temporary one due to transportation size limitations, and the tank is shipped to the site. For this reason, the upper cover 1 could not be welded during test assembly at the factory, and the joining flange of the upper cover 1 and lower tank 2 that constitute the tank was a
As shown in the figure, the entire circumference of the flange was tightened at equal intervals with a plurality of tightening tools such as a shank 7, with the gasket 4 held in between.

When the tank formed by the upper cover 1 and the lower tank 2 is under vacuum, pressure P acts toward the inside of the tank due to external pressure as shown by the arrow, and the flange 3 of the lower tank 2 slips with the gasket 4 and slips into the tank. I'm about to try. Therefore, as shown in Figure b, a plurality of vacuum anti-slip fittings 5 supported by the edge of the upper cover 1 were provided at appropriate positions between the fasteners 7 on the edge of the lower tank 2. This anti-slip fitting 5 was a temporary part until the test was completed or the sealing welding was performed after the main cover was attached, but installing such a fitting would require a large amount of materials and man-hours. Also the second
As shown in the figure, after the cover is installed, the entire circumference of the flange joint is joined by welding 6, but when internal pressure is applied to the tank during an accident as described above, a bending moment M acts around the weld 6, causing the flange joint to There is a risk that the weld 6 may peel off.

For this reason, conventionally, as shown in FIGS. 3a and 3b, after the welding 6 of the flange joint is completed, the upper main reinforcing member 8 and the lower tank 2 are fixed on the upper cover 1 between the lower tank 2 and the upper cover 1. A removable connection reinforcing metal fitting 12 is attached between the lower main auxiliary member 10 fixed to the outer wall of the main body, and is tightened with bolts and nuts 13 to withstand internal pressure due to internal failures, etc.

However, such a structure is complicated and requires drilling holes for tightening bolts and nuts, resulting in poor workability.

[Purpose of the invention]

It is an object of the present invention to provide a tank for oil-filled electrical equipment that eliminates the above-mentioned drawbacks, has a simple structure, increases tank strength, reduces materials and man-hours, and has good workability.

[Summary of the invention]

In order to achieve the above-mentioned object, the present invention provides a U-shaped stopper that sandwiches the flanges of the upper cover and the lower tank mainly near the main reinforcing member on the side wall of the tank, and prevents the concentrated load near the main reinforcing member during vacuum lubrication. It is characterized by having both a durable anti-slip function and a metal fitting that can withstand the moment of the flange joint when internal pressure is applied to the tank.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 4a and 4b. The same parts as the conventional ones shown in FIGS. 1, 2, and 3 will be described with the same reference numerals.

The main reinforcing material 8 of the cover 1 and the main reinforcing material 10 of the lower tank 2 are provided with U-shaped fasteners 5a on the opposing centers of the flanges 3, and the flange 3 is inserted into the main reinforcing material 8 of the upper cover 1. A receiving metal fitting 5b is separately welded and fixed onto the reinforcing member 8 in opposition to this stopper metal fitting 5a. This structure allows the flange 3 to shift due to external pressure during tank vacuum lubrication, and serves as a stopper by receiving the force of the stopper 5a and resisting the force of the stopper 5b. In addition, the stopper fitting 5a and the receiving fitting 5b have a structure that serves to determine the guide position when the tanks are combined, and are also used to prevent slippage in the case of full-circumference welding 6 of the tank joint, which is performed after the transformer verification test. It has a structure that can be carried out with the metal fitting 5a and the receiving metal fitting 5b attached. Finally, the stopper 5a and the receiver 5b are welded to form an integrated structure, and the tank joint becomes a strong structure that has the function of the conventional tank connection reinforcement fitting 12.

〔Effect of the invention〕

As described above, according to the present invention, the fasteners are attached separately to the main reinforcing material at one or two locations around the tank, and are connected to the corresponding receiving metal fittings, thereby making it possible to tighten the shakuman, etc. Even when tightened with fittings, the tank joint, which is considered to be weak against vacuum pressure, can be provided with sufficient strength, making it possible to simplify or reduce the need for horizontal reinforcing materials and the like. Additionally, this stopper also serves as a guide for positioning when fitting the tanks together, eliminating the need for conventional guide fittings. Ultimately, the stopper is integrated with the receiver and serves as a reinforcing metal for the tank joint, so it can maintain sufficient strength to withstand internal pressure in the event of an internal accident during operation of the transformer.

As described above, the tank for oil-filled electrical equipment of the present invention has a simple structure of a stopper and a receiving metal.
This has the effect of improving the strength of the tank, reducing materials and man-hours, improving workability, and reducing the weight of the tank.

[Brief explanation of drawings]

Figures 1a and b are cross-sectional views showing the tank joint during conventional vacuum lubrication, Figure 2 is a cross-sectional view showing the state of the tank when the internal pressure is deformed, and Figure 3a is a tank with a connecting reinforcing metal fitting structure. FIG. 4A is a sectional view showing a tank having a stopper structure according to an embodiment of the present invention, and FIG. 4B is a side view thereof. 1... Upper cover, 2... Lower cover, 3...
flange, 4... gasket, 5a... stop metal fitting, 5b... receiving metal fitting, 6... welding (joint part).
8... Upper tank main reinforcing material, 10... Lower tank main reinforcing material, 14... Transformer contents, 15... Welding (slip prevention fitting joint location).

Claims (1)

[Claims] 1. In a tank for oil-filled electrical equipment that houses the main body of oil-filled electrical equipment and consists of an upper cover and a lower tank, a U-shaped fastener that sandwiches the flanges of the upper cover and lower tank is attached to the main reinforcing material of the lower tank. A tank for oil-filled electrical equipment, characterized in that a receiving metal fitting is fixed to the upper cover, which is installed nearby, receives the force of this stopper due to external pressure when vacuum oil is filled into the tank, and is welded to the stopper after oil filling.