JPS59169119A - Stationary induction electric apparatus - Google Patents

Abstract

PURPOSE:To reduce vibration of a sound shielding plate by providing a dynamic vibration absorber which has the structure that a weighting body for dynamic vibration absorber consisting of a plurality of stacked weight body segment is supported by a support through an elastic body to the sound shielding plate. CONSTITUTION:A number of sheets of stacked weight body segments 20 is adjusted so that multiplication coefficient of a weight body for dynamic vibration absorber for vibration of electromagnetic vibrator becomes maximum when the dynamic vibration absorber 11 is attached on the electromagnetic vibrator and is vibrated at the maximum number of vibrations. When the dynamic vibration absorber 11 thus adjusted is attached to the weight body 6, the vibration of attaching area is suppressed to a lower number of vibrations. However, a frequency where vibration at the attaching point is minimized, namely the vibration absorbing frequency is different little by little at the attaching points of dynamic vibration absorber 11. Accordingly, under the actual vibrating condition, an adjusting bolt 25 is rotated for each dynamic vibration absorber 11 at each attaching point, a lock nut 26 is rotated and a push plate 23 is moved. Thereby, deflection of counter spring 24 is changed and the vibration absorbing frequency can also be adjusted.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to stationary induction electric appliances such as transformers and reactors.
In particular, the present invention relates to a soundproofing device that reduces noise generated from the tank.

[Prior art]

Recently, as urban areas have expanded and residential areas have been built closer to substations and the like, there has been an increasing demand for low noise static induction appliances.

Most of the noise from stationary induction appliances comes from magnetostrictive vibrations generated in the iron core of the appliance, which radiate from the tank into the atmosphere through the bottom plate and insulating oil.

Soundproofing measures using concrete and steel plates have traditionally been used as noise countermeasures. This is a method of insulating or absorbing sound by placing the appliance itself inside a soundproof building made of concrete or steel plates2.

However, this method has various drawbacks such as an increase in the installation area of the equipment, a long construction period, and an increase in costs.

Therefore, as shown in Figs. 1 to 3, a thin plate 4 made of a thin steel plate and having a predetermined number of spring lengths is provided at the peripheral end of a reinforcing stay 3 fixed by welding on the side plate 2 of the tank 1. The present inventors have recently proposed a method of supporting the sound plate 5 and arranging a weight body 6 having an annular rectangular shape near the boundary between the thin plate 4 and the sound plate 5 (Japanese Patent Application Laid-Open No. -56-87306). In addition, inside tank 1,
An electric appliance body consisting of an iron core 7 and a winding 8 is housed, and mineral oil 9 is filled. Further, a bushing lO is attached to the upper part of the tank 1, and connects the winding and the external '&J: wire. According to this method, noise reduction can be achieved efficiently in a simple manner, and the above-mentioned drawbacks can be overcome.

However, even with such a vibration-proofing effect of the thin plate 4 and the weight body 6, it is difficult to reduce the vibration transmitted from the reinforcing stay 3 to the sound damping plate 5 to a sufficiently satisfactory level. Vibration is still transmitted and noise is radiated,
This has become an obstacle to further reducing noise levels.

[Object of the Invention] An object of the present invention is to provide a stationary induction electric appliance that eliminates the drawbacks of the prior art described above and can further reduce noise with a simple structure. [Summary of the Invention] In order to achieve the object, the present invention provides a dynamic vibration absorber configured by supporting a weight body for a dynamic vibration absorber consisting of a plurality of laminated heavy body pieces on a support body via an elastic body. is installed, and this dynamic vibration absorber reduces the vibration of the tone plate.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. The figure will be explained in detail. In addition, in these figures, figures 1 to 3
The same reference numerals as in the figures indicate the same or equivalent parts.

The difference between this embodiment and FIGS. 1 to 3 is that dynamic vibration absorbers 11 are attached to appropriate locations of the annular square weight body 6, for example, at each corner. This dynamic vibration absorber 11 includes a U-shaped national body 12 fixed to the weight body 6,
Leaf springs 13, 14, 1 are installed between the opposing surfaces of this national polity 12.
5. A weight body 19 for a dynamic vibration absorber consisting of a stacked body of a mold body mounting member 17 for a dynamic vibration absorber attached via a bolt 16 and a plurality of heavy body pieces 20 fixed to this mounting member 17 with bolts 18. and a push plate 23 attached between opposing surfaces of the national body 12 via leaf springs 21 and 22; and a disc spring 24 interposed between the push plate 23 and the mounting member 17; It is composed of an adjustment bolt 25 that passes through the soundproof plate 5, the weight body 6, the national body 12, the mounting member 17, the disc spring 24, and the push plate 23 from the outside, and a lock nut 26 screwed onto the tip of this bolt 25. There is.

The vibrations transmitted from the reinforcing stay 3 to the weight body 6 via the thin plate 4 and the sound plate 5 are
2 and plate springs 13 to 16 to form a dynamic vibration absorber weight body 1.
9, causing it to vibrate. By the way, magnetostrictive vibrations have harmonics that are even multiples of the power supply frequency.

Therefore, the number of the weight body pieces 20 to be stacked is adjusted so that the natural frequency of the single weight body 19 for a dynamic vibration absorber substantially matches the frequency with the maximum vibration among these harmonics.

Specifically, when the dynamic vibration absorber 11 is mounted on an electromagnetic vibrator and vibrated at a frequency that maximizes the vibration, the vibration magnification of the dynamic vibration absorber weight body 19 with respect to the vibration of the electromagnetic vibrator is maximum. The number of stacked heavy body pieces 20 is adjusted so that.

When each dynamic vibration absorber 11 adjusted in this way is attached to the weight body 6, the dynamic vibration absorber weight body 19 resonates due to the vibration of the weight body 6, and a large reaction force corresponding to the vibration is applied to the weight body 6'. Since the vibration is applied to the attachment point of the dynamic vibration absorber 11 in substantially the opposite phase to the vibration at the attachment point, the vibration at the attachment point is suppressed and becomes extremely small.

However, the frequency at which the vibration at the attachment point is the smallest, that is, the vibration absorption frequency, differs slightly depending on each attachment point of the dynamic vibration absorber 11. Therefore, in the state of actual vibration, the adjustment bolt 2 for each dynamic vibration absorber 11 at each attachment point is
By rotating the lock nut 26 and moving the push plate 23, the amount of deflection of the disc spring 24 is changed to absorb vibration 2. ′:! Adjust the wave number.

The disc spring 24 has a so-called non-linear spring characteristic in which the spring constant source changes depending on the amount of deflection. On the other hand, the vibration absorption frequency is determined by the weight of the dynamic vibration absorber weight body 19 and the number of springs of each of the plate springs 13 to 16 and the disc spring 24, similarly to the natural frequency. Therefore, by changing the amount of deflection of the disc spring 24 and changing its spring constant as described above, the vibration absorption frequency can be made to match the frequency of the weight body 6 for each dynamic vibration absorber 11 at each attachment point. The vibration of the weight body 6 can be extremely reduced. As a result, the vibration of the soundproof plate 5 is also extremely reduced, and the vibration and sound effects of the soundproof plate 5 are significantly improved.

According to this embodiment, the following effects can be obtained.

(1) Since the dynamic vibration absorber weight body 19 is composed of a plurality of laminated heavy body pieces 20, its natural frequency can be easily matched to the frequency of the weight body 6 by adjusting the number of laminated pieces. By doing so, the vibration of the weight body 6 can be reduced and the sound effect of the sound plate 5 can be increased.

(2) Furthermore, a two-step adjustment method is adopted in which the amount of deflection of the disc spring 24 is changed for each dynamic vibration absorber 11 at each attachment point, so that the vibration absorption frequency can be accurately matched to the frequency of the weight body 6. , the sound effect of the sound plate 5 can be further increased.

Note that instead of the disc spring 24 used in the above embodiment, a coil spring with nonlinear characteristics, such as a conical spring or an uneven pitch spring, may be used.

Further, as the sound damping plate, it is desirable to use a damping steel plate made by laminating a plurality of thin steel plates with plastic or joining them by spot welding, or a dividing plate made of a plastic material with good damping properties. In the case of using a damping steel plate made of a plurality of thin steel plates as described above, one of the thin steel plates is extended, and this extension is made into a thin plate with the above-mentioned spring characteristics, and it is directly welded to the reinforcing stay. You can also do it. Alternatively, the weight body 6 can be omitted and the dynamic vibration absorber can be attached directly to the tone plate, and the same effect can be obtained in this case as well.

Furthermore, a permanent magnet can also be used as the heavy body element,
In this case, the laminated heavy body pieces? There is no need to tighten screws, and the heavy body piece can be attached and detached with a simple touch.
Adjustment of the number of stacked heavy body pieces becomes extremely easy.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to reduce the vibration of the bellows due to the vibration-proofing effect of the dynamic vibration reducer, and improve the sound effect of the bellows.

Moreover, since the weight body of the dynamic vibration absorber has a laminated structure, its natural frequency can be easily made to match the frequency of the tone plate by adjusting the number of laminated layers.

[Brief explanation of the drawings] Figure 1 is a longitudinal side view showing the overall configuration of a conventional low-noise transformer, Figure 2 is an enlarged side view of the main parts of Figure 1 viewed from the direction of the arrow, and Figure 3. is a sectional view taken along line BB in FIG. 2, and FIG. 4 is a vertical sectional side view showing the overall configuration of a transformer according to an embodiment of the present invention.
Figure 5 is an enlarged side view of the main parts of Figure 4 viewed from the direction of arrow C;
6 is an enlarged cross-sectional view of the dynamic vibration reducer portion of the transformer shown in FIG. 4, and FIG. 7 is a cross-sectional view taken along the line ])-D in FIG. 6. 2...tank side plate, 3...reinforcement stay, 4...thin plate, 5...shiya tone plate, 6...heavy body, 11...dynamic vibration absorber, 12...national polity ( support), 13 to 16...
Leaf spring, 19... Heavy body for dynamic vibration absorber, 20... Weight body piece, 24... Dish confectionery 3rd 2nd 4th 5th mouth 6th country

Claims (1)

[Claims] 1. A plurality of structural members are provided on the side plate of the tank that houses the main body of the electric appliance, and a plurality of structural members protrude from the side plate, and a sound plate is installed between the structural members with a thin plate having spring characteristics interposed therebetween. In the supported stationary induction electric appliance, a dynamic vibration absorber configured by supporting a weight body for a dynamic vibration absorber consisting of a plurality of laminated heavy body pieces on a support body via an elastic body is attached to the sound isolation plate. A stationary induction electric appliance characterized by: 2. A stationary induction electric appliance according to claim 1, wherein the heavy body piece is made of a permanent magnet. 3. The stationary induction electric appliance according to claim 1, wherein the elastic body includes an elastic body having nonlinear spring characteristics at least in part.