JPS6025012B2 - Earthquake resistant transformer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention particularly relates to an earthquake-resistant transformer that increases the natural frequency of the transformer and improves its seismic strength.

[Background of the invention]

Generally, a transformer has wires wound around the iron D and is stored in a tank or cubicle, or in the case of a molded type, it is installed and fixed directly on the floor, but when considered as an earthquake-resistant transformer. , winding portions, etc. are not particularly relevant to the gist, so they will be omitted and explained with reference to FIGS. 1 to 3.

The core leg 1 of the core, which is formed by layering a plurality of steel plates, has a contact plate 3 arranged on both outer side surfaces in the stacking direction with an insulating plate 2 interposed therebetween, and the upper and lower yoke parts are provided with upper and lower fasteners 4, They are fixed together via 5. The winding wire is wound around the core leg 1 between the upper and lower fasteners 4 and 5. In the case of an earthquake, an iron core configured in this manner hardly responds to seismic waves in the direction of arrow A, but in response to seismic waves in the direction of arrow B, deformation due to slipping etc. occurs in the laminated parts of the core legs 1. The upper part of the iron core vibrates greatly, as shown by the two-dot chain line in FIG.

This amount of deformation is related to the rigidity of the core leg 1, but if the natural frequency of the core is the same as or near the seismic wave, the lower fastener 5 will be fixed to the floor via the base 6. 3, which is the intersection of the upper end of the lower metal fitting 5 and the iron O-leg 1, and swings greatly around the C part in FIG. If the core cannot withstand this deformation or if the foundation bolts (not shown) fixing the base 6 break, the transformer will fall over and move. Therefore, in order to prevent falling, sliding, etc., the rigidity of the iron core leg can be increased by increasing the continuous pressure of the laminated iron ○ or by reducing the number of laminated iron sheets without changing the cross section. However, it is difficult to adopt this method because it may increase the iron loss of the transformer and deteriorate the electrical characteristics. In addition, increasing the thickness of the backing plate also increases the weight of the transformer, so the effect is considered to be offset. Generally, when a transformer is simulated by a simple one-mass point vibration system as shown in FIG. 4, its natural frequency fo (day 2) is expressed by the formula m.

ra = Still cod...'1' However, k: Spring constant of iron core (k9/arc) W: Weight (k
9) Generally, the predominant frequency of seismic waves is between 05 and 10 Hz, and in order to improve the seismic strength of the transformer, the natural frequency f of the transformer must be adjusted.

It is necessary to make it as high as possible to avoid resonance with seismic waves. For this purpose, as is clear from equation (1), there are two possible methods: reducing the weight W or increasing the spring constant k of the iron part, but there are other ways to drastically change the weight W. There are restrictions in order to satisfy the electrical characteristics of Since the spring constant in the direction of arrow B (core lamination direction) is small, the natural frequency is low and the core legs fall down. [Object of the Invention] The purpose of the present invention is to improve seismic strength. Our goal is to provide earthquake-resistant transformers.

[Summary of the invention]

In the seismic transformer of the present invention, in order to increase the bending rigidity of the base of the core leg, the shape of the plate is adjusted at least at the lower fastener part within a range that does not form a closed circuit interlinking with the magnetic flux in the circumferential direction of the core leg. Since the core leg is formed with a curved part consisting of a semicircular part surrounding the core leg, the earthquake resistance of the core leg can be particularly improved in the B direction.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 5A, B, and C and FIG. 6.

The contact plate 3 and the insulating plate 2 are reinforced by forming a curved part 7 consisting of a semicircular ring shape so that the bottom metal fitting 5 part and slightly above it surround the iron core leg 1, and facing each other from both sides. The tips of the curved portions 7 are spaced apart.

Further, the curved portion 7 of the contact plate 3 forms an inner curved portion 7A where the core legs 1 correspond to each other, and a lower end contact plate portion 78,
The inner curved portion 7A is curved along the shape of the core leg 1, and a substantially triangular space is formed between the inner curved portion 7A and the lower end side contact plate portion 7B, and the flat plate portion 8 is inserted into the space. do. The flat plate part 8, the inner curved part 7A, and the lower end side slope part 7B are welded together, and an insulating paper 9 is arranged between the lower surface side of the flat plate part 8 and the yoke IA. If the gap between the flat plate part and the yoke is large, the total Qinsu paper may be omitted. The outer curved portion 7C, where the core legs 1 do not correspond to each other, is formed so as to surround a portion of the yoke IA and the core leg 1 that correspond to the lower fastener 5. In this core configuration, the joint between the core leg 1 near the lower fastener and the yoke IA is the inner curved part 7A.
Since the iron leg 1 is surrounded by the outer curved portion 7C and has increased mechanical strength, the iron leg 1 vibrates in the A and B directions.
This made it difficult for iron core leg 1 to fall over. In particular, iron core leg 1
When it vibrates in direction B, simply forming a curved portion will have weak mechanical strength, and there is a risk that the curved portion will open outward. Therefore, in the present invention, the outer curved portion 7C is formed to extend to the yoke IA side, and the inner curved portion 7C is formed to extend to the yoke IA side.
A and the lower end side abutment plate part 7B are integrally connected by a flat plate part 8, and the mechanical strength of each part is increased to withstand vibration in the B direction. In this way, the seismic transformer of the present invention has
By simply changing the shape of the backing plate, the rigidity of the core can be increased without increasing the weight of the core, and by increasing the natural frequency of the transformer, it is possible to increase the earthquake resistance.

Therefore, the risk of serious accidents such as the transformer falling over can be reduced. FIG. 7 shows another embodiment, and the difference from the above embodiment is that in the above embodiment, the reinforced part of the curved part 7 of the backing plate 3 is formed to the lower fastener 5 part and a part slightly above this. In contrast, in this embodiment, the curved portion 7 is provided over the entire length of the core leg 1, and has the same effect as the above embodiment.

[Effects of the Invention] As described above, the seismic transformer of the present invention has the effect of improving seismic strength and reducing the risk of accidents such as the transformer falling over.

[Brief explanation of the drawing]

Figure 1 is a plan view of a conventional transformer in which the iron 0 and the fastener are connected, Figure 2 is a front view of Figure 1, Figure 3 is a right side view of Figure 2, and Figure 4 is a transformer. Explanatory diagram of the vibration system model of the vessel, Figure 5A
1 is a front view of the coupled state of the iron core and the fastener of the embodiment of the seismic transformer of the present invention, FIG. B is a sectional side view of the main part of FIG. Perspective view, Figure 6 is W- in Figure 5.
FIG. 7 is an enlarged cross-sectional view taken in the direction of the arrows, and FIG. 7 is a front view showing a part of the state in which the iron core and the vertical fitting are connected in another embodiment of the seismic transformer of the present invention. 1... Core leg, 3... Backing plate, 4...
・Upper fastener, 5...Bottom fitting, 7...Curved part, 7A and 7C...Inner and outer curved parts, 8...Flat plate part. Tsutomu 1 figure Tsutomu 2 figure 3 figure Tsutomu 4 figure hair 7 figure conflicting figure Tsutomu 5 figure

Claims (1)

[Claims] 1 At least two core legs formed by laminating a plurality of steel plates and arranged at predetermined intervals, a yoke connecting the upper and lower ends of the core legs, and a yoke connecting the upper and lower ends of the core leg and the yoke. A core consisting of an upper clamp and a lower clamp that tighten and fix the lower ends, and a plate placed between the upper clamp, the lower clamp, and the core leg, which corresponds to the lower clamp. The contact plate has an inner curved part and a lower end side contact plate part formed on the inside where the core legs correspond to each other, and an outer curved part formed on the opposite side of the inner side, and the inner curved part is a part of the core leg. The outer curved part surrounds the core leg and a part of the yoke, and forms a semicircular curved part with the tips separated from each other, and the inner curved part and the lower end side abutment plate part An earthquake-resistant transformer characterized in that a flat plate portion corresponding to the yoke is installed between the yoke and the yoke.