JPH0353461Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] This invention relates to an improvement of the core structure of an external iron type transformer.

[Conventional technology]

Figures 2 and 3 show the internal structure of a conventional outside iron transformer.
As shown in the figure. Note that FIG. 2 is a sectional view of the inside of the transformer, and FIG. 3 is a sectional view taken along the - line in FIG.

In Figures 2 and 3, 1 is a coil insulation group;
Reference numeral 2 designates a leg core that is installed separately with a gap in the window of the coil insulation group 1, and 3 is an inverted T-shaped beam that is provided below the leg core 2 and supports the leg core. , 3a indicate the vertical plate portion of this beam 3. 4 is an electromagnetic shield attached to the lower surface of the beam 3, 5 is an electromagnetic shield attached to the upper part of the leg core 2, 6 is a lower tank, 7 is an upper tank, 8 is between the leg cores 2 divided into two. This is the flow of insulating oil that flows through 9 and cools the leg iron core.

A conventional outside iron transformer is configured as described above.
In order to arrange the beam vertical plate 3a, which is a strength member of the beam 3, between the two divided leg iron cores 2, the dimension between them is larger than the thickness of the beam vertical plate 3a.

Also, from the perspective of cooling the leg cores 2, the distance between the cores is determined by the thickness of the beam vertical plate 3a and is larger than the dimension required for core cooling.
The flow velocity of the insulating oil flowing through the leg iron core is low, and the thermal conductivity from the leg iron core to the oil is low, reducing the cooling effect.

[Problem that the invention attempts to solve]

As mentioned above, in conventional external iron type transformers, the space between the two leg cores is the same from the bottom to the top of the core, so the area between them is large and the window area of the coil insulation group is The ratio of the core cross-sectional area to the In other words, there was a problem in that the coil insulation group had to be made larger.

In addition, the flow rate of insulating oil determined by the shape, size, number, etc. of the oil passage holes in the beam 3, which accounts for most of the oil flow resistance of the insulating oil flowing between the iron cores, increases when the distance between the leg iron cores is large. It is small, and the heat transfer coefficient is also small.
Therefore, there was a problem in that the cooling effect of the leg iron core was also reduced.

This invention was made to solve these problems, and the purpose is to obtain a transformer with a simple configuration, a smaller coil insulation group, and good core cooling efficiency.

[Means for solving problems]

In the transformer according to this invention, the width of the leg core, which is divided into two parts installed in the window of the coil insulation group via the center line, is changed depending on the core stacking height position, and the leg core width is changed in the core stacking height direction. It has been changed.

[Effect]

In this design, the distance between the leg cores is set to the minimum required value, so there is no wasted space, and the coil insulation group becomes smaller.Also, by reducing the distance between the legs, the oil flow rate increases and the heat transfer coefficient increases. Iron core cooling improves over time.

〔Example〕

FIG. 1 shows an embodiment of this invention. In the figure, 10 is a leg core provided with a stepped portion 10a so as to widen the core width above the vertical plate portion 3a of the beam 3, and 11 is a leg core provided with a step 10a between the vertical plate portions 3a of the beam 3. This is the flow of insulating oil flowing through 〓9. Note that the other configurations are the same as those of the above-mentioned conventional device, so explanations thereof will be omitted.

In the external iron type transformer configured as above,
The width of the core above the vertical plate portion 3a of the beam 3 is increased, and the dimension between the leg cores is set to the minimum value necessary for cooling and construction, so the core cross section relative to the window area of the coil insulation group is The ratio of the area occupied by the coil is increased, that is, the coil insulation group is made smaller.

Also, since the space between the cores has become smaller, the flow rate of the insulating oil flowing between the cores has increased, and the heat transfer coefficient from the core surface to the insulating oil has increased, improving cooling.

[Effect of idea]

As described above, this idea consists of forming a flow path by symmetrically abutting leg iron cores with stepped parts, increasing the core width above the vertical plate part of the beam, and reducing the distance between the leg iron cores in that part. This has the effect that the coil insulation group can be made smaller and the cooling of the leg core can be improved.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of this invention, FIG. 2 is an internal sectional view of a conventional external iron transformer, and FIG. 3 is a sectional view taken along the line - in FIG. In the figure, 1 is a coil insulation group, 3 is a beam, 3a is a vertical plate portion of the beam, 9 is a gap, 10 is a leg core, and 10a is a stepped portion. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] The leg core passing through the window of the coil group is installed in two parts in the core width direction, and has a structure in which insulating oil for cooling the core flows between the leg cores, and an inverted leg core that supports the leg core at the bottom of the leg core. In an external iron transformer with a T-shaped beam, the stepped portion 10a
The leg cores 10 provided with the above are arranged symmetrically against each other, and at the center of the upper extension of the vertical plate portion 3a of the beam 3, a narrower gap 9 is formed between the leg cores in the portion where the vertical plate is located. An external iron type transformer characterized by: