JP6631030B2 - Stationary induction appliance - Google Patents

Description

   The present invention relates to a stationary induction device in which a stationary induction device main body is housed in a tank, and a sound insulating plate is mounted on an outer surface of the tank.

As this type of static induction device, for example, static induction devices described in Patent Documents 1 and 2 are known.
The stationary induction device described in Patent Literature 1 has an upper support point and a lower support provided on an upper reinforcing beam fixed to the side of a tank accommodating a stationary induction device main body together with an insulating medium and on a foundation on which the stationary induction device is installed. A sound insulation plate attached between both support points of the points so as to cover the outer surface of the tank side surface, wherein the sound insulation plate is attached with a band-shaped reinforcing rib surrounding the periphery of the surface; It comprises a first elastic element disposed between the upper support point and a flexible sealing member for closing a gap created between the sound insulating plate and the tank side surface.

  In the stationary induction device described in Patent Document 2, a plurality of tank reinforcing members are provided at arbitrary intervals in a vertical direction or a horizontal direction on an outer surface of a tank of the static induction device, and a predetermined thickness is provided between adjacent tank reinforcing members. And a first sound insulation panel provided with a panel reinforcing member on the back surface of the sound insulation plate body, and the sound insulation plate body and the panel reinforcement member of the first sound insulation panel were directly welded to the tank reinforcement member. Having a configuration.

JP-A-10-149920 JP 2012-146776 A

However, in the conventional examples described in Patent Literatures 1 and 2, since a reinforcing member is attached to the sound insulating plate or the sound insulating support is used, the structure of the static induction device becomes complicated, and the number of parts increases. There is a problem that the production cost increases.
In addition, the rigidity of the sound insulation plate is increased to reduce the noise sufficiently. However, when the stationary induction device is a transformer, the power supply frequency is basically doubled due to the magnetostriction of the iron core and the electromagnetic force acting on the windings. Vibration mainly composed of frequency components from the first to sixth order having a frequency (100 Hz or 120 Hz) is generated and propagates to the sound insulating plate. However, since it is difficult to avoid resonance of the sound insulating plate, a sufficient noise reduction effect is obtained. There is a problem that can not be demonstrated to
SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the conventional example, and has as its object to provide a static induction device capable of exhibiting a sufficient noise reduction effect with a simple configuration.

In order to achieve the above object, a stationary induction device according to one embodiment of the present invention is mounted with a stationary induction device main body, a tank that houses the static induction device main body, and a peripheral portion fixed to an outer surface of the tank, A plurality of sound insulation plates arranged side by side in the vertical direction, wherein the sound insulation plate is calculated by dividing the average value of the vibration amplitude in the region other than the fixed region of the peripheral portion by the average value of the vibration amplitude in the fixed region. The vibration response magnification at each frequency becomes 1 or less at a frequency of 2 times or more of the power supply frequency of the stationary induction electric appliance main body , and the sound insulation plate is elastically provided only on the support member side on the support member formed on the outer wall of the tank. The bolt is fastened through a body, and the bolt is fastened with a tightening torque of 1/2 or less of a specified tightening torque determined by a bolt diameter and a material.

  According to one aspect of the present invention, the vibration response magnification when the sound insulating plate is mounted on the tank is set to 1 or less in a frequency region equal to or more than twice the power supply frequency of the stationary induction electric device main body. Therefore, the reinforcing member is provided on the sound insulating plate. A sufficient noise reduction effect can be exhibited without any noise.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows one Embodiment of the stationary induction device which concerns on one aspect of this invention. It is a side view of FIG. FIG. 2 is an enlarged cross-sectional view illustrating the sound insulating plate mounting structure of FIG. 1. It is a vibration characteristic diagram which shows the vibration response magnification with respect to the frequency of general structural steel and the damping steel plate. It is a resonance curve figure for demonstrating a Q value method. It is a figure showing the model for analysis of a damping steel plate. It is a characteristic line figure which shows the vibration response magnification with respect to the frequency at the time of changing the loss coefficient (damping ratio) of a damping steel plate. It is a graph which shows the area | region where a 3rd natural frequency becomes 100 Hz or less from the relationship of the horizontal length and vertical length of a sound insulation board.

  Next, an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between the thickness and the planar dimension, the ratio of the thickness of each layer, and the like are different from actual ones. Therefore, specific thicknesses and dimensions should be determined in consideration of the following description. In addition, it is needless to say that dimensional relationships and ratios are different between drawings.

Further, the embodiments described below exemplify an apparatus and a method for embodying the technical idea of the present invention, and the technical idea of the present invention is based on the material, shape, structure, The arrangement is not specified as follows. The technical concept of the present invention can be variously modified within the technical scope defined by the claims described in the claims.
First, an embodiment of a stationary induction device representing one aspect of the present invention will be described.

As shown in FIG. 1, the stationary induction device includes a stationary induction device main body 11 composed of, for example, a transformer and a reactor, a tank 12 for accommodating the stationary induction device main body 11, and an outer surface of the tank 12. And a sound insulation plate 13.
The stationary induction device main body 11 has a configuration in which a winding 11b is wound around a magnetic core 11a, and AC power with a frequency of 50 Hz or 60 Hz is supplied from a commercial AC power supply.
The tank 12 is formed in a box shape by a top plate 12a, a bottom plate 12b, left and right side plates 12c, and front and rear side plates 12d, and accommodates the stationary induction device main body 11 therein. Insulating medium such as insulating oil or gas is filled in order to increase the pressure.

  The sound insulating plate 13 is mounted on the outer surfaces of the left and right side plates 12c and the front and rear side plates 12d of the tank 12, and taking the left and right side plates 12c as an example, as shown in FIGS. Sound insulation plate support members 14a, 14b, and 14c also serving as tank reinforcing members arranged to extend in the front-rear direction at the upper, middle, and lower stages of the surface, and extend vertically between these sound insulation plate support members 14a to 14c. It is mounted on a lattice-shaped support portion composed of the arranged sound insulation plate support members 14d and 14e which also serve as a tank reinforcing member.

Each of the sound insulating plate supporting members 14a to 14e is fixed to the left and right side plates 12c of the tank 12 by fixing means such as welding, and the sound insulating plate 13 is mounted on the outer side surface opposite to the mounting surface.
When the sound insulating plate 13 is mounted on the outer side surface of the sound insulating plate supporting member 14a, as shown in FIG. 3, the same length as the sound insulating plate supporting member 14a is used. In the state where the long gaskets 15a having the above elasticity are arranged, the bolt insertion holes 13a formed in the peripheral portion of the sound insulation plate 13 on these gaskets 15a are aligned with the female screw portions 14f formed in the sound insulation plate support member 14a. The flat washer 16 is arranged outside the bolt insertion hole 13a of the sound insulating plate 13, and the bolt 17 is engaged with the female screw portion 14f from the outside of the flat washer 16 through the flat washer 16 and the bolt insertion hole 13a to be tightened. .

  At this time, the bolt 17 is relatively loosely tightened with a tightening torque of about の of a specified tightening torque determined by the bolt diameter and the material. By making the tightening torque smaller than the specified torque, a buffer function can be provided between the sound insulating plate and the support member, and vibration transmission between the support member and the sound insulating plate can be reduced. The extent to which the tightening torque is made smaller than the specified torque can be appropriately selected depending on the materials of the bolts and the support members, the weight of the sound insulating plate, and the like, but is preferably in the range of 1/2 to 1/5.

  If the tightening torque is larger than 1/2 of the specified tightening torque, the vibration transmission rate between the support member and the sound insulating plate increases, so that a sufficient damping effect cannot be obtained, and 1/5 of the specified tightening torque. When the tightening torque is further reduced, the risk that the sound insulating plate cannot be supported by the bearing surface pressure of the bolt or the bolt is loosened due to vibration and detaches suddenly increases. If there is a concern that the bolt may become loose, a screw lock agent made of, for example, an adhesive may be applied to the bolt 17 and fixed as a loosening prevention.

  The sound-insulating plate 13 is made of, for example, a damping steel plate having a thickness of 4.1 mm. When the sound-insulating plate 13 is mounted on the tank 12 as described above, the peripheral portions corresponding to the gaskets 15a to 15c of the damping steel plate in FIG. The vibration response magnification for each frequency calculated by dividing the average value of the vibration amplitude in the region excluding the fixed region Af indicated by hatching by the average value of the vibration amplitude in the fixed region Af is the commercial value of the static induction appliance main body 11. The frequency is 1 or less at a frequency of 2fa (100 Hz or 120 Hz) or more, which is twice the frequency fa (50 Hz or 60 Hz) of the AC power supply.

As shown by the solid line in FIG. 4, the vibration-damping steel sheet has a lower vibration response magnification at the first to fifth natural frequencies than SS400, which is a general structural steel shown by the dotted line in FIG.
The present inventors have conducted various experiments on the damping steel plate. As a result, the vibration response magnification in the frequency band that is the main noise due to the vibration noise of the stationary induction device is determined by the loss coefficient η (damping ratio ζ) of the sound insulating plate 13. Was found to change depending on the value of.

Here, the loss coefficient η is an evaluation index of the vibration-proof material, and is calculated by, for example, the Q value method. The damping ratio ζ is used for the vibration characteristics of the structure, and is similarly calculated by the Q value method. In the Q value method, a value obtained by dividing the peak frequency f ₀ obtained from the resonance curve shown in FIG. 5 by the frequency difference Δf at the displacement 3 dB lower than the peak value is calculated as the Q value (= f ₀ / Δf). The Q value, the loss coefficient η, and the damping ratio ζ have a relationship of η = 1 / Q and ζ = １ ／ Q.
Therefore, the loss coefficient η is represented by the following equation (1).
η = 1 / Q = Δf / f ₀ (1)
Similarly, the damping ratio ζ is represented by the following equation (2).
ζ = １ ／ Q = Δf / 2f ₀ (2)
Therefore, the damping ratio ζ is の of the loss coefficient η.

A damping steel plate having a width of 1230 mm, a length of 930 mm, and a thickness of 4.1 mm shown in FIG. 6 was used as an analysis model of the sound insulating plate, and a loss coefficient η was set as a comparative example. A vibration analysis simulation was performed by applying an exciting force of 1 [G] to the three types of = 0.10 and case 3 = 0.20, and the vibration response magnification for each frequency was determined.
FIG. 7 shows the results of the vibration analysis simulation. As is clear from FIG. 7, in case 1, which is a comparative example in which the loss coefficient is 0.05 and the damping ratio ０．０ is 0.025, as shown by the resonance curve L1 shown by the dotted line in FIG. The vicinity of the primary natural frequency (28 Hz) and the vicinity of the tertiary natural frequency (66 Hz) are lower than the power supply frequency × 2 times the frequency 2fa, the vibration response magnification exceeds 1, and the power supply frequency × In a frequency band (100 Hz to 500 Hz) where noise reduction is expected to be twice or more, the vibration response magnification exceeds 1 in the vicinity of 300 Hz and 400 Hz, and the vibration response magnification in the range of 300 Hz to 350 Hz and 400 Hz to 450 Hz. Since the magnification is approaching 1, a large sound reduction effect cannot be exhibited.

  However, in case 2 in which the loss coefficient is 0.10 and the damping ratio ０．０５ is 0.05 in the present embodiment, as shown by the resonance curve L2 shown by the solid line in FIG. Although the vibration response magnification exceeds 1, the vibration response magnification is lower than 1 in a frequency band where noise reduction is expected to be equal to or higher than the power supply frequency × 2, and a large noise reduction effect can be produced. .

Further, in case 3 of the present embodiment in which the loss coefficient is 0.20 and the damping ratio ０．１ is 0.10, as shown by the resonance curve L3 shown by the dashed line in FIG. The vibration response magnification exceeds 1, but the vibration response magnification falls below 1 near the third natural frequency, and furthermore, a frequency band in which noise reduction is expected to be equal to or higher than the power supply frequency × 2 times the frequency of 2fa. In this case, the vibration response magnification is sufficiently lower than 1, and a greater sound reduction effect can be produced.
From the above results, by setting the loss coefficient of the damping steel plate constituting the sound insulating plate 13 to 0.1 or more, that is, the attenuation ratio to 0.05 or more, it is possible to reduce the noise at twice or more the power supply frequency. The vibration response magnification can be set to 1 or less, and a sufficient sound reduction effect can be exhibited.

The natural frequency of the sound insulating plate can be changed by changing the size and the like of the sound insulating plate. For example, if the third natural frequency of a rectangular sound insulating plate having a thickness of 4.1 mm is to be set to 100 Hz or less, a practical size is calculated by FEM analysis, and the vertical length a and the horizontal length b of the sound insulating plate 13 are as shown in FIG. 8 is a hatched area.
Each sound insulating plate 13 is fastened to the sound insulating plate supporting members 14a to 14e via the gaskets 15a to 15e by the flat washer 16 and the bolt 17 with a tightening torque lower than a specified tightening torque.
By covering the left and right side plates 12c and the front and rear side plates 12d of the tank 12 with the sound insulating plate 13, it is possible to assemble a static induction device having a low noise structure.

  As described above, by selecting a sound insulating plate having a high loss coefficient, the frequency band in which the vibration response magnification exceeds 1 is limited to only the vicinity of the low-order natural frequency, and the band is supplied to the stationary induction electric appliance main body 11. If the frequency is set to be lower than the frequency 2fa which is twice the frequency of the power supply, an effective sound reduction effect can be exhibited.

According to the present embodiment, the sound insulating plate 13 itself can exhibit an effective sound reducing effect, and the sound insulating plate 13 does not require a reinforcing member for increasing rigidity. As a result, the weight can be reduced, and the number of components can be reduced, so that the manufacturing cost of the stationary induction device can be reduced.
Moreover, the mounting structure of the sound insulating plate 13 to the sound insulating plate supporting members 14a to 14e is such that gaskets 15a to 15e having elasticity are interposed between the sound insulating plate supporting members 14a to 14e and the sound insulating plate 13. Since only the flat washer 16 needs to be interposed in the, it can be simplified.
That is, when the sound insulating plate 13 is normally bolted to the sound insulating plate supporting members 14a to 14e, the sound insulating plate 13 is transmitted from the tank 12 via the bolts 17 with an elastic body such as a rubber sheet interposed on both sides of the sound insulating plate 13. It is common to suppress vibration.

  However, since this embodiment focuses on the relationship between the loss coefficient of the sound insulating plate and the vibration response magnification, it is necessary to interpose an elastic body for vibration insulation from the bolt 17 on the head side of the bolt 17. And the number of parts can be reduced accordingly. In addition, when an elastic body is interposed on the head side of the bolt 17, the elastic body is exposed to ultraviolet rays, which tends to cause deterioration, and requires maintenance such as inspection and replacement. In the embodiment, since no elastic body is required outside the sound insulating plate 13, maintenance such as inspection and replacement can be omitted.

Further, since the tightening torque for attaching the sound insulating plate 13 to the sound insulating plate supporting members 14a to 14e with the bolts 17 is set to a tightening torque smaller than a specified tightening torque determined by the bolt diameter and the material, the tightening of the bolts 17 is performed. The attachment can prevent the sound insulation plate 13 from being deformed at the bolted position, and the gaskets 15a to 15e can be reduced in deformation amount.
In the above embodiment, the case where a damping steel plate having a thickness of 4.1 mm and a loss coefficient η of 0.1 is applied as the sound insulating plate 13 has been described. However, the present invention is not limited to this. As long as the vibration response magnification is 1 or less in the frequency range of 2 times or more and 2fa or more, a sound insulating plate having an arbitrary thickness and an arbitrary loss coefficient can be applied.

It is preferable that the shape of the sound insulating plate 13 is the same as that of the sound insulating plate 13. Also, the shape is not limited to a rectangle, and a sound insulating plate of any shape can be combined.
Further, the present invention is not limited to the case where the gaskets 15a to 15e are interposed between the sound insulating plate supporting members 14a to 14e and the sound insulating plate 13, and any other elastic member such as a sealing member having another elasticity or rubber can be interposed. .

  In the above embodiment, the case where the sound insulating plate 13 is fixed to the sound insulating plate supporting members 14a to 14e with the bolts 17 has been described. However, the present invention is not limited to this, and the sound insulating plate supporting members 14a to 14e may be A protruding male screw portion may be formed, the sound insulating plate 13 may be disposed on the protruding male screw portion via gaskets 15a to 15e, and furthermore, the nut may be fastened with a flat washer 16 via a nut.

  Reference numeral 11 denotes a stationary induction electric device main body, 11a denotes a magnetic core, 11b denotes a winding, 12 denotes a tank, 13 denotes a sound insulating plate, 14a to 14e: a sound insulating plate support member, 14f: a female screw portion, 15a to 15e: a gasket, 16: a flat washer, 17: bolt, Af: fixing area

Claims (5)

A stationary induction machine body,
A tank for storing the stationary induction body,
A sound insulation plate fixedly attached to the outer surface of the tank at the peripheral edge thereof and arranged in a plurality in a vertical direction,
The sound insulation plate has a vibration response magnification for each frequency calculated by dividing an average value of vibration amplitudes in a region other than a fixed region of a peripheral portion by an average value of vibration amplitudes in the fixed region. it becomes 1 or less 2 times the frequency of the power frequency,
The sound insulation plate is fastened to a support member formed on an outer wall of the tank by a bolt only on the support member side via an elastic body, and the bolt is 1/1 / specified tightening torque determined by a bolt diameter and a material. Fastened with a tightening torque of 2 or less,
A static induction device characterized by the following. The bolt is stationary induction apparatus according to claim 1, wherein that you have been fastened by 1/5 or more of the tightening torque of the specified tightening torque determined by the bolt diameter and material. The stationary induction device according to claim 1, wherein a plurality of the sound insulation plates are arranged in a horizontal direction on an outer surface of the tank . 4. The stationary induction device according to claim 1, wherein the sound insulation plate has a loss coefficient representing a vibration suppression performance set to 0.1 or more . 5. The said sound insulation board is set so that the 3rd natural frequency at the time of the said tank installation may be 2 times or less of the power supply frequency of the said stationary induction-electric-apparatus main body, The Claim 1 characterized by the above-mentioned. The static induction device according to the paragraph.

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