JP2921680B2 - Transformer - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial application field) The present invention relates to a transformer taking measures against earthquakes.

(Prior Art) Conventionally, as is well known, there is a transformer in which an iron core formed by laminating a large number of iron core plates is installed such that each leg thereof is directed in a vertical direction. A coil is wound around the leg.

An example of this type of transformer is shown in FIG. The upper and lower portions of the laminated iron core 1 are fastened by fasteners 2 respectively. The iron core 1 is installed on an installation surface such that its leg 1a is oriented in the up-down direction. A coil 3 is wound around the leg 1a, and the upper and lower ends of the coil 3 are connected and fixed to the clamp 2 by bolts 4.

When the transformer receives the seismic wave, a phenomenon occurs in which the upper part swings in the direction of arrow A with the lower part as a fulcrum, as shown in FIG. At this time, since the coil 3 is bolted to the iron core 1, it swings with the iron core 1.

Now, when the vibration characteristics in the direction of arrow A in FIG. 9 that easily resonate with the seismic wave are analyzed, the results are as shown in FIG. FIG. 10 shows the relationship between the natural frequency of the transformer and the displacement mode. As can be seen from FIG. 10, a primary mode is observed around a frequency of 5 Hz, which is a falling mode. In addition, a secondary mode is observed around a frequency of 16 Hz, which is a torsional mode. Such characteristics are slightly different depending on the type and size of the transformer, but are substantially the same in all transformers.

(Problems to be solved by the invention) By the way, since the frequency of the earthquake is in the range of 0.5 to 10 Hz, in order to prevent the transformer from falling down due to the seismic wave, a method of increasing the natural frequency of the transformer, There is a method of forcibly suppressing vibration due to resonance.

However, in transformers with laminated cores,
Due to the structure, slippage occurs between the iron core plates, the bending rigidity in the direction of arrow A in FIG. 9 is small, and the natural frequency cannot be increased. In this case, it is conceivable to increase the bolt tightening force of the fastener 2 for tightening the iron core 1. However, this is naturally limited and the natural frequency cannot be increased. Further, as a device for forcibly damping, as shown in Japanese Patent Publication No. 58-43886, there is a configuration in which a stay for vibration suppression is provided in an oblique manner. There is a disadvantage that the installation space becomes large.

The present invention has been made in view of the above circumstances, and its purpose is to provide a laminated iron core, despite the fact that the natural frequency is low, without requiring a vibration damping stay, etc. An object of the present invention is to provide a transformer capable of obtaining a remarkable earthquake resistance effect with a simple configuration.

[Constitution of the Invention] (Means for Solving the Problems) The present invention relates to an iron core formed by laminating a large number of iron core plates, each leg being installed so as to be directed in the vertical direction, and the legs of the iron core. And a coil wound around the upper and lower portions of the coil, and a spring member made of a metal spring material which is vertically expandable and contractible and can be flexibly deformed in the horizontal direction on the upper and lower portions of the iron core. It is characterized in that it is supported in the up-down direction through the intermediary.

(Operation) According to the above means, the upper and lower portions of the coil are vertically connected to the upper and lower portions of the iron core via a spring member made of a metal spring material which is vertically expandable and contractible and deformable in the horizontal direction. Because of the support, the primary fall mode of the iron core and the primary fall mode of the coil act in opposite directions, that is, the vibration of the coil and the spring with respect to the core vibration system (vibration system during an earthquake). The system acts as a dynamic vibration absorber. Therefore, even if a seismic wave and resonance occur, the vibration of the entire transformer is reduced, and the earthquake resistance can be improved.

(Embodiment) A first embodiment of the present invention will be described below with reference to FIGS.

FIGS. 1 and 2 show a dry three-phase transformer. The iron core 11 is formed by laminating a large number of iron core plates, which are legs 12, 13 and 14 which are directed in the vertical direction.
Having. The upper end of the iron core 11 is sandwiched between a pair of upper fasteners 15, 16 having a substantially U-shaped cross section to be bolted. The lower end of the iron core 11 is also sandwiched between a pair of lower fasteners 17, 18 having a substantially U-shaped cross section to be bolted. The lower fastening members 17 and 18 are fixed to a base member 19 fixed to the floor via an insulating plate 20.

Each leg 12, 13 and 14 of the iron core 11 has a coil 21, 22
And 23 are wound. Each coil 21, 22 and 23
Are attached to the iron core 11 by a fixture 25 having a spring member 24, respectively. More specifically, as shown in FIG. 3, a mounting member 25 includes a spring member 24 formed of a compression coil spring formed of a metallic spring material between both end plates 27, 27 each having a screw 26 attached thereto. It is configured by attaching. The spring member 24 can expand and contract in the up-down direction and bend and deform in the horizontal direction. Then, the upper and lower end faces of the coils 21, 22 and 23 are fixed to the fastening fittings 15, 1 by the mounting fixture 25.
6,17 and 18 and thus each coil 21,22 and 23
Are supported on the iron core 11 through the spring member 24 in the up-down direction.

In the above configuration, since the coils 21, 22, and 23 are attached to the iron core 11 via the spring members 24, the transformer has a two-degree-of-freedom vibration system around one coil. As shown in FIG. 4, the two-degree-of-freedom vibration system has a mass m ₁₁ and a spring constant k ₁₁ system and a mass m ₁₁
It is modeled by the ₂₁ and the spring constant K ₂₄ systems. In this case, the mass m ₁₁ is the total mass of the iron core 11 (each fastening bracket 15 to 18
Corresponds to 1/3 of the mass of including) the spring constant k ₁₁ is equivalent to the bending rigidity of the core 11. The mass m ₂₁ corresponds to the mass of each coil for example coil 21, the spring constant k ₂₄ corresponds to the spring constant of the spring member 24.

Now, assuming that the natural frequency is ωn, Here, ω ₁₁ ² = k ₁₁ / m ₁₁ ω ₂₂ ² = k ₂₄ / m ₂₁ μ = m ₂₁ / m ₁₁ (mass ratio).

The above equation, by calculating the k _24, it is possible to obtain an action as dynamic vibration absorber of the vibration system of two degrees of freedom. Therefore, as shown in FIG. 5, when the coil 21 (22, 23) vibrates left and right in the primary falling mode, the coils 21 (22, 23) vibrate left and right in the opposite primary falling mode, and the vibrations cancel each other. As a result, in a laminated iron core type transformer whose natural frequency cannot be increased, even if resonance occurs due to a seismic wave having a frequency of 0.5 to 10 Hz, vibration can be reduced and seismic resistance is greatly improved.

In the above embodiment, the spring member 24 is formed of a compression coil spring. However, the spring member is not limited to this, and is formed of a metal spring material that can expand and contract in the vertical direction and bend and deform in the horizontal direction. 6 and 7, for example. In FIG. 6 showing the second embodiment, the spring member 28 is constituted by a zigzag-shaped leaf spring, and in FIG. 7 showing the third embodiment, the spring member 29 is constituted by a substantially U-shaped leaf spring. Make up. Also, in the above embodiment, a three-phase transformer has been illustrated,
It may be applied to a single-phase transformer.

[Effects of the Invention] As is clear from the above description, the present invention provides a laminated iron core, in which the upper and lower portions of the coil are vertically extended and contracted and deformed in the lateral direction by connecting the upper and lower portions of the core to the upper and lower portions. Since the supporting member is supported in the vertical direction via a spring member made of a possible metal spring material, the vibration system of the coil and the spring member acts as a dynamic vibration absorber against the vibration system of the iron core.
A remarkable earthquake resistance effect can be obtained with a very simple configuration without requiring a vibration damping stay or the like.

[Brief description of the drawings]

1 to 5 show a first embodiment of the present invention. FIG. 1 is an overall side view, FIG. 2 is a front view of the same, FIG. 3 is a vertical side view of a fixture, and FIG. FIG. 5 is a diagram showing a model of a vibration system, and FIG. 5 is a side view showing an example of a vibration state. Sixth
FIG. 7 is a perspective view of a spring member according to a second embodiment of the present invention, and FIG. 7 is a side view of the spring member according to the third embodiment.
8 and 9 show a conventional example, FIG. 8 is a diagram corresponding to FIG. 1, FIG. 9 is a diagram corresponding to FIG. 5, and FIG. 10 is a diagram showing vibration characteristics. In the figure, 11 is an iron core, 12, 13, and 14 are legs, 21, 22, and 23.
Is a coil, and 24, 28 and 29 are spring members.

Claims (1)

(57) [Claims] An iron core comprising a plurality of iron core plates laminated, each leg being installed so as to be directed in a vertical direction, and a coil wound around said leg of said iron core. The upper and lower portions of the coil are supported on the upper and lower portions of the iron core in the vertical direction via a spring member made of a metal spring material which is vertically expandable and contractible and can be flexibly deformed in the horizontal direction. And transformer.