JPH10116741A - Magnetic shield for stationary induction unit and fixing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate conduction noise by laminating a plurality of sheets of silicon steel strip of specified content on the front side facing a coil and laminating a grain oriented silicon steel strip on the rear side. SOLUTION: The magnetic shield 3 comprises a magnetic shield part 6 formed by laminating a plurality of sheets of 6.5% silicon steel strip on the front side facing a transformer coil 2 in parallel with the tank wall 4, and a magnetic shield part 7 formed by laminating a plurality of sheets of grain oriented silicon steel strip on the rear side. Since the magnetic shield part 6 formed by laminating 6.5% silicon steel strips having high rigidity on a steel strip saturated magnetically or gradually approaching saturation has high receptivity and small saturation magnetic strain, Joule's loss is decreased and magnetostrictive oscillation can be reduced significantly. Leakage flux flowing into the magnetic shield part 7 formed by laminating grain oriented silicon steel strips on the rear side is shunted to the magnetic shield part 6 and the quantity of flux is reduced correspondingly. Consequently, loss is reduced and magnetic saturation is avoided along with the state gradually approaching saturation thus reducing magnetostrictive oscillation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic shield of a stationary induction device for forming a flow path of leakage magnetic flux of a transformer, for example, and a method of mounting the same.

[0002]

2. Description of the Related Art In a transformer, for example, the larger the capacity, the larger the amount of magnetic flux leakage from the coil. This leakage magnetic flux flows into a clamp for fixing an iron core made of silicon steel and the coil, or a tank wall. A so-called eddy current is generated. When this eddy current flows through the clamp or the tank wall, local heat generation increases due to Joule loss, and there are often problems such as deterioration of insulating material and insulating oil, and deterioration of heat radiation performance due to a rise in tank temperature. In the worst case, the transformer may malfunction or break down.

As means for reducing the Joule loss due to the eddy current, a magnetic shield for forming a flow path of a leakage magnetic flux in a transformer is generally provided.
As this magnetic shielding material, a silicon steel strip having a high specific resistivity and a high saturation magnetic flux density is often used because it is an inexpensive material that can tolerate a large amount of leakage magnetic flux flowing therein and has a low generation loss.

Generally, as shown in FIG. 35, in a transformer, a coil 2 is wound around each leg of an iron core 1, and the iron core 1 on which these coils 2 are wound is a pair of clamps provided on upper and lower portions thereof. 14 and is attached to the tank floor and the tank upper cover and housed in the tank.

In such a transformer, a magnetic shield 3 is provided on the tank wall 4 so as to surround the coil 2.
The magnetic shield 3 is provided between the clamp 14 and the coil 2 so as to cover the clamp 14. The magnetic shield 3 is formed by laminating silicon steel strips, bonding with resin, bolting, caulking or the like.

Further, as the magnetic shield 3, the steel strip surface is made to face the coil 2 by the forming method (the steel strip surface is horizontally laminated on the tank wall or the clamp surface).
There is a vertical type in which a horizontal type and a steel strip stacking surface are opposed to each other (the steel strip surface is vertically stacked on a tank wall or a clamp surface).

In the horizontal magnetic shield, since the surface of the steel strip faces the coil, the leakage magnetic flux flows in perpendicular to the surface, so that the eddy current path becomes longer and the generation loss increases. It has the feature of easy installation.

The vertical magnetic shield is not easy to manufacture, fix, and attach, but has the characteristic that the eddy current path is shortened and the generated loss is reduced because the steel strip laminated surface faces the coil. ing.

In particular, a vertical magnetic shield is a special shield material because, as with a horizontal magnetic shield, the loss generated by an iron core plate or the like placed in a state in which leakage magnetic flux flows vertically into the steel strip surface is reduced. As shown in Japanese Patent Laid-Open No. 57-52116, a proposal has been made to adopt a 6.5% silicon steel strip. The specific resistivity of this 6.5% silicon steel strip is the same as that of a normally used silicon steel strip (specific resistivity: 45 μΩ · c
It is known that the occurrence of Joule loss can be significantly reduced because it has a value about twice that of m). In addition, for the core plate and the core fastening jig, for example,
As disclosed in JP-A-85928 and JP-A-57-26821, a proposal has been made in which a slit is formed in the surface of the plate, but this can also shorten the eddy current path and reduce the Joule loss as in the above proposal. This has the effect.

[0010]

The purpose of providing a magnetic shield in a transformer is to introduce the leakage magnetic flux to the magnetic shield so that the leakage magnetic flux flows into the tank wall and the clamp and does not generate local heat due to eddy current. The heat generation is suppressed by the low loss characteristic of the material. Further, the proposals described in the above-mentioned publications focus on suppressing the generation loss of the magnetic shield to a lower level.

By the way, the noise when power is supplied during the operation of the transformer, that is, the so-called conduction noise, is becoming more and more noticeable as the transformer is downsized and the load form is diversified. During the course of various tests conducted by the present inventors, it was found that the influence of the magnetic shield could not be ignored.

The conduction noise was considered to be mainly due to the vibration of the coil, but this vibration is attenuated to some extent when it reaches the tank due to the damping effect of oil, an insulating structure or the like.

On the other hand, since the magnetic shield is installed directly on the tank wall, for example, the vibration reaches the tank without being attenuated, so that it has been found that the magnetic shield is also one of the causes of noise. . further,
Even with the same magnetic shield, it was confirmed that the vibration of the horizontal type was larger than that of the vertical type. Further, as a result of actually measuring the vibration / displacement and the magnetic flux density distribution of the magnetic shield, the following knowledge has been obtained.

(A) In the horizontal magnetic shield, when a leakage magnetic flux flows in, a reverse magnetic field due to a large eddy current generated on the surface of the steel strip suppresses the flow of the magnetic flux in the stacking direction. The magnetic flux distribution in the thickness direction is greatly different. That is,
This shows a magnetization configuration in which magnetic flux sequentially flows from a steel strip closer to the coil to a steel strip after the magnetic saturation has been reached (sequentially in the stacking direction).

In general, it is known that when the magnetic flux density of a directional silicon steel strip exceeds 1.8 T, the amount of magnetostriction (expansion and contraction of the steel strip due to magnetization) increases in each step.

Accordingly, the steel strip closer to the coil is in an excessively magnetically saturated state, and the vibration due to its magnetostriction becomes larger than expected. Further, the magnetic waveform of each steel strip includes distortion and large harmonics due to local magnetic saturation, and noise increases due to their synergistic effect.

(B) In the vertical type magnetic shield, since the laminated surface faces the coil, the amount of magnetic flux flowing into each steel strip is almost the same, and the magnetic flux distribution is smaller than that of the horizontal type magnetic shield. Is greatly improved. Therefore, the vibration is not as great as in a horizontal magnetic shield.

However, since the material used for the shield is a directional silicon steel strip, the magnetic permeability in other directions (90 ° direction, 45 ° direction, etc.) is very poor compared to the longitudinal direction of the shield.

In the vertical magnetic shield, the width direction (depth direction) of the vertical magnetic shield coincides with the 90 ° direction, and is not as extreme as the horizontal magnetic shield. However, there is a certain degree of non-uniformity of the magnetic flux distribution in the width direction. . That is, the closer to the coil, the higher the magnetic flux density. Therefore, the magnetostriction becomes larger on the coil side, and a relatively large magnetostriction vibration occurs as a shield.

(C) Recently, a plurality of devices that generate harmonics, such as rectifiers, are connected to the load of a transformer, and the load current contains harmonic currents in many cases. If a harmonic component is included in the load current, it is naturally included in the leakage magnetic flux, and therefore, the harmonic component is also included in the magnetostriction of the magnetic shield. It is well known that harmonic components of magnetostriction significantly increase noise.

(D) Both the vertical and horizontal magnetic shields
A thin (about 0.35 mm) and long (several hundred cm) steel strip is laminated to a thickness of several tens of mm, integrated by resin bonding, welding, or binding. Fixed to At this time, magnetic flux flows in the magnetic shield in the longitudinal direction, and magnetostriction occurs in that direction.However, since the elongation in the longitudinal direction is limited by the fixed part, the magnetic shield is distorted in the direction of the magnetic shield lamination with low bending rigidity. The vibrating force is applied. That is, the magnetic shield has a large bending vibration in the longitudinal direction, which is a main cause of an increase in noise.

(E) Leakage magnetic flux from the coil flows into the magnetic shield from all parts and flows while gathering in the longitudinal direction. Therefore, the distribution of the magnetic flux density in the longitudinal direction is greatly different, and a region having a locally high magnetic flux density exists. As an example of this, for example, in the case of a magnetic shield installed on a tank wall, the magnetic shield part facing the position of a half height of the coil corresponds, and there is a case where the magnetic flux density greatly exceeds 1.8 T depending on the use condition. is there.

(F) The magnetostrictive vibration of the magnetic shield is:
Vibration is transmitted to the tank wall as well as transmitted to the air, and acts as a vibrating force to vibrate the tank wall having low rigidity. That is, the vibration is transmitted to the outside of the tank through the tank wall, and not only generates noise, but also causes the tank wall itself to vibrate and generate noise. Further, when the tank wall has a flexible structure, unexpected vibration and noise are caused due to resonance of the tank wall and the like. For example, in the measurement example of a large-capacity reactor, the noise level is lower than that of the tank wall on which the magnetic shield is installed.
In some cases it was expensive.

In this case, it is considered that the magnetostrictive vibration of the magnetic shield is one of the causes of vibration and noise as well as the vibration of the coil and the excitation of the iron core.

The mounting of the vertical magnetic shield to the tank wall or the clamp may be performed by fixing the bolt after resin bonding or by fixing the pedestal to the bolt after welding to the pedestal.

However, in the former case, the width of the steel strip used for the vertical magnetic shield is generally only about several tens of mm, but the bolt holes for fixing are not small.
At that point, the magnetic flux density becomes significantly higher. As a result, loss and increase in magnetostrictive vibration are caused, so that the presence of a bolt hole in the magnetic shield is not preferable. Further, a method of welding to a pedestal after fixing by resin impregnation without providing a bolt hole cannot be used because the resin layer is destroyed by welding heat. That is, in the case of the vertical magnetic shield, the method of fixing to the tank wall or the clamp poses a problem, but in practice, the latter method of welding the pedestal to the pedestal by bolting is practical. In addition, since the welding to the pedestal is performed by MIG welding, the magnetic shield made of a thin plate is easily deformed by the heat input. Therefore, the pedestal cannot be welded at a short pitch, and the pedestal is welded at a wide interval. There is a need.

A magnetic shield evaluation test was performed under these conditions, and the following findings were obtained.

(A) Since the magnetic permeability of the vertical magnetic shield is not deteriorated due to impregnation of the resin under vacuum or the like, very good shield characteristics were obtained.

However, compared to the horizontal magnetic shield, the vibration due to the magnetostriction of the vertical magnetic shield did not decrease as expected.

(B) The vertical magnetic shield is thin (0.
A long (several hundred cm) steel strip with a thickness of several tens of mm is laminated, and is clamped at several places with bolts and fixed to the tank wall. As the fixing means, a pedestal is welded to one side of the shield to fix the pedestal, and does not press the shield itself like a horizontal magnetic shield.

That is, the other surface of the shield is in a free state, and the steel strips are separated without firm contact. For this reason, each of the steel strips vibrates on its own, and the transfer of magnetic flux between the steel strips has a synergistic effect, resulting in loud noise such as chatter.

The above problem can be solved by fixing the other surface of the shield. However, if welding, a fastener or the like is used, a short circuit is formed with the welded portion of the pedestal, and the magnetic shield is not used. Disappears. That is, a large loss (heat generation) occurs at the short-circuit portion, which is a problem.

In the case of using a vertical magnetic shield having good shield characteristics as described above, chatter between steel strip layers of the magnetic shield and lateral bending vibration due to magnetostriction are reduced. Without increasing the bending rigidity in the longitudinal direction.

The present invention has been made in view of these circumstances, and improves the magnetic flux distribution of the magnetic shield of the stationary induction device, and improves the rigidity of the magnetic shield in the stacking direction where the rigidity of the magnetic shield is weak, thereby contributing to one factor of the conduction noise. It is an object of the present invention to provide a magnetic shield of a stationary induction device and a method of mounting the same, which can eliminate the cause of current noise by reducing magnetostrictive vibration of the magnetic shield.

[0035]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a magnetic shield for a stationary induction device and a method for mounting the same, which take the following measures.

According to a first aspect of the present invention, there is provided a horizontal magnetic shield in which a silicon steel strip is laminated on a tank surface of a stationary induction device so that its surface is parallel to the tank surface. A plurality of 6.5% silicon steel strips are stacked and arranged, and a directional silicon steel strip is stacked on the rear surface.

Therefore, according to the magnetic shield of the stationary induction device having the above-described configuration, the leakage magnetic flux from the stationary induction device coil is disposed on the steel strip surface facing the coil 6.5.
Due to the high specific resistivity of the% silicon steel strip, the amount of eddy current generated in the plane is reduced by half. Furthermore, in the magnetization process of the magnetic shield, which takes a magnetic flux distribution with a higher magnetic flux density toward the surface,
5. The surface steel strips in magnetic saturation and magnetic asymptotic state
The extremely low saturation magnetostriction of the 5% silicon steel strip significantly reduces magnetostrictive vibration, and does not lead to magnetic saturation and magnetic saturation asymptotically even in the magnetic shield consisting of a directional silicon steel strip disposed on the rear surface. , The state of extremely small magnetostrictive vibration is maintained. In the case of a grain-oriented silicon steel sheet, the magnetostriction that does not reach magnetic saturation is sufficiently small, but the magnetostriction rapidly increases when saturation occurs.

According to a second aspect of the present invention, there is provided a vertical magnetic shield in which a silicon steel strip is laminated on a tank surface of a stationary induction electric device so that the surface thereof is vertical, and the magnetizing material is magnetized in a direction perpendicular to the rolling direction. A two-way silicon steel strip material with an easy axis is used.

Therefore, according to the magnetic shield of the stationary induction device having the above-described configuration, a bidirectional silicon steel strip is used as a material for the magnetic shield, and the inflow direction of the leakage magnetic flux from the stationary induction device coil, that is, the coil is opposed to the coil. Since the direction of easy magnetization of the bidirectional silicon steel strip, that is, the direction perpendicular to the rolling direction in which the permeability and loss are good, is matched with the width direction of the steel strip from the lamination surface to the lamination surface on the opposite side. Quickly spreads over the entire width direction and flows uniformly in the longitudinal direction of the magnetic shield along the rolling direction, which is also the direction of easy magnetization.

According to a third aspect of the present invention, there is provided a vertical magnetic shield in which a silicon steel strip is laminated on a tank surface of a stationary induction device so that the surface is vertical, and a plurality of sheets are provided on both sides of the laminated portion. 6.5% silicon steel strip is laminated and arranged.

Therefore, according to the magnetic shield of the static induction device having the above-described configuration, the magnetic flux is transmitted at a high frequency in the inflow direction of the leakage magnetic flux from the static induction device coil, that is, on both sides of the lamination surface facing the coil. 6.5% with high magnetic susceptibility
Since the magnetic shield part made of silicon steel strip is arranged, the harmonic leakage magnetic flux generated by the harmonic current flowing through the coil does not flow to the magnetic shield part made of directional silicon steel strip. 5. Low loss
A large amount flows to the magnetic shield portion made of a 5% silicon steel strip.

According to a fourth aspect of the present invention, in the magnetic shield installed on the tank surface of the stationary induction device, a pair of magnetic shield members formed by laminating silicon steel strips bent in an L-shape in the width direction are turned inward. , And a magnetic shield member is provided in a space surrounding the magnetic shield member.

Therefore, according to the magnetic shield of the stationary induction device having the above-described configuration, a pair of magnetic shields formed by laminating silicon steel strips bent in an L-shape in the width direction are used.
By providing high rigidity in the longitudinal direction of the magnetic shield and providing a horizontal magnetic shield part in the space surrounding it,
Since the shield width is reduced, the eddy current path generated in the plane can be shortened, and the loss can be reduced.

According to a fifth aspect of the present invention, there is provided a magnetic shield installed on a tank surface of a stationary induction appliance, wherein a pair of magnetic shield members formed by laminating silicon steel strips bent in an L-shape in the width direction are directed outward. With one on each side
The pair of magnetic shield members are arranged so as to be in contact with the lower side of the magnetic shield member.

Therefore, according to the magnetic shield of the stationary induction device having the above-described configuration, a pair of magnetic shield portions formed by laminating silicon steel strips bent in an L-shape in the width direction are used.
By providing a high rigidity in the longitudinal direction of the magnetic shield and facing the pair of vertical magnetic shields outward, a pair of horizontal magnetic shields disposed on both sides of the space on the lower side thereof is The dimension does not have to exactly match the lower dimension of the L-shaped magnetic shield. In addition, the flat horizontal magnetic shield part is divided into two shield widths.
The eddy current path generated in the plane can be halved, and the loss can be halved.

According to a sixth aspect of the present invention, there is provided a magnetic shield installed on a tank surface of a stationary induction device, wherein a magnetic shield member formed by laminating silicon steel strips bent in a U-shape in the width direction and a space surrounding the magnetic shield member. Combine with a magnetic shield member arranged to fill.

Therefore, according to the magnetic shield of the stationary induction device having the above-described configuration, the U-shaped magnetic shield member has extremely high rigidity in the longitudinal direction of the magnetic shield.
In addition, since the horizontal or vertical magnetic shield portion is arranged so as to fill the surrounding space, it is easy to mount the magnetic shield portion on the U-shaped magnetic shield portion.

According to a seventh aspect of the present invention, in a magnetic shield installed on a tank surface of a stationary induction device, a silicon steel strip is wound in a cylindrical shape and then elongated in an elliptical shape, and the silicon steel strip is stretched in an oblong shape. , And the outer peripheral surface thereof is opposed to the stationary induction coil.

Therefore, according to the magnetic shield of the stationary induction device having the above-described configuration, since the steel strip on the long side on the coil facing side and the long side on the tank wall side are continuous, the leakage flowing from the coil facing side can be prevented. The magnetic flux easily wraps around the tank wall.

According to an eighth aspect of the present invention, in the magnetic shield installed on the tank surface of the stationary induction device, the silicon steel strip is wound in a cylindrical shape and then elongated in an oblong shape, and the long side of the opposite side is opposed to the long side axis. Are pressed to contact each other, and the laminated surface faces the stationary induction coil.

Therefore, according to the magnetic shield of the stationary induction device having the above-described configuration, since the steel strip is continuous between the opposing long sides, the magnetic flux easily goes around to the opposing long sides. In addition, rigidity can be increased by fixing at the arc portion, and mounting becomes easy.

According to a ninth aspect of the present invention, in a magnetic shield installed on a tank surface of a stationary induction device, a silicon steel strip is wound into a cylindrical shape, then elongated into an oblong shape, and a flat plate is formed on an inner peripheral portion thereof. Are arranged, and the outer peripheral surface thereof is opposed to the stationary induction coil.

Therefore, according to the magnetic shield of the stationary induction device having the above-described configuration, since the steel strip on the long side facing the coil and the long side on the tank wall side are continuous, the leakage flowing from the side facing the coil can be prevented. The magnetic flux easily goes to the tank wall side and the cross-sectional area at the center of the shield increases, so that there is no portion where the magnetic flux density locally increases.

According to a tenth aspect of the present invention, in a magnetic shield installed on a tank surface of a stationary induction device, a silicon steel strip is wound into a cylindrical shape, then elongated into an oblong shape, and a flat plate is formed on the inner peripheral portion thereof. Are arranged, and the laminated surface thereof is opposed to the stationary induction coil.

Therefore, according to the magnetic shield of the stationary induction device having the above-described configuration, since the steel strip is continuous between the opposing long sides, the magnetic flux easily goes around to the opposing long sides, and Since the cross-sectional area at the center of the shield increases, the magnetic flux density locally increases.

According to an eleventh aspect of the present invention, in a magnetic shield installed on a stationary induction lamp clamp, a silicon steel strip is wound into a cylindrical shape, formed into a desired size, fixed, and fixed on the clamp. I do.

Therefore, according to the magnetic shield of the stationary induction device having the above-described configuration, the magnetic shield formed and fixed in the form of a wound iron core is fixed on a clamp around the entire circumference of the iron core, thereby reducing the magnetic flux distribution. , A vertical magnetic shield having high rigidity can be formed, and can be relatively easily mounted on the stationary induction device.

According to a twelfth aspect of the present invention, there is provided a vertical magnetic shield in which a silicon steel strip is laminated on a tank surface of a stationary induction device so that the surface thereof is vertical, and the width of the central portion is set at both ends. To be wider than

Therefore, according to the magnetic shield of the stationary induction device having the above-described configuration, since the width of the central portion of the vertical magnetic shield is made wider than the width of both ends, the leakage magnetic flux is concentrated, and the high magnetic flux is concentrated. The cross-sectional area of the central portion of the magnetic shield that increases the density can be increased, thereby lowering the magnetic flux density and reducing the magnetostriction.

According to a thirteenth aspect of the present invention, in a magnetic shield installed on a tank surface and a clamp of a stationary induction device, a thick steel strip is used as a silicon steel strip used for a shield member.

Therefore, according to the magnetic shield of the stationary induction device having the above-described configuration, by increasing the thickness of the steel strip, the magnetic flux due to the leakage magnetic flux flowing into the shield surface or flowing in the longitudinal direction of the shield. Therefore, the rigidity against bending vibration caused by magnetostriction is greatly improved, and vibration can be reduced.

According to a fourteenth aspect of the present invention, there is provided a horizontal magnetic shield in which a silicon steel strip is laminated on a tank surface of a stationary induction device so that its surface is parallel, and a narrow and thick wall is provided on the shield surface. This plate is installed along the shield longitudinal direction.

Therefore, according to the magnetic shield of the stationary induction device having the above-described configuration, the narrow and thick plate attached to the shield surface is fixed together with the shield with the fixing bolt, so that the shield of the shield is secured. Bending vibration can be forcibly suppressed.

According to a fifteenth aspect of the present invention, there is provided a horizontal magnetic shield in which a silicon steel strip is laminated on a tank surface of a stationary induction device so that the surface thereof is parallel to the tank, and the surface of the steel strip is extended along the longitudinal direction. One or more slits are formed.

Therefore, according to the magnetic shield of the stationary induction device having the above-described configuration, when the leakage magnetic flux flows into the surface of the horizontal magnetic shield facing the coil and penetrates in the laminating direction, it is generated in the plane. Since the current path through which the eddy current flows is cut off by the slit provided in the steel strip, the eddy current amount can be reduced. That is, not only the eddy current loss can be reduced, but also the leakage magnetic flux does not need to receive the reverse magnetic field due to the eddy current, and can easily penetrate in the stacking direction, so that the magnetic flux distribution in the stacking direction becomes uniform.

According to a sixteenth aspect of the present invention, in a horizontal magnetic shield in which a silicon steel strip is laminated on a tank surface of a stationary induction device so that its surface is parallel, the directional silicon steel strip is formed into a cylindrical shape. After winding, it is cut at one place into a block shape, and further, the thickness reduction portion is bent and deformed inward to form a flat surface in the longitudinal direction of the shield.

Therefore, according to the magnetic shield of the stationary induction device having the above configuration, both ends of the steel strip existing in the laminating direction of the horizontal magnetic shield are all arranged on the surface of the shield, that is, the surface facing the coil. Therefore, the leakage magnetic flux can easily flow into both ends without receiving a reverse magnetic field due to the eddy current. For this reason, the magnetic flux distribution in the stacking direction becomes uniform.

According to a seventeenth aspect of the present invention, there is provided a vertical magnetic shield in which a silicon steel strip is laminated on a tank surface of a stationary induction device so that its surface is perpendicular to the tank surface. Are fixed in the laminating direction at a narrow pitch.

Therefore, according to the magnetic shield of the stationary induction device having the above-described structure, the silicon steel strip layers are partially fixed and integrated at a narrow pitch in the longitudinal direction of the vertical magnetic shield. The rigidity of the magnetic shield in the stacking direction increases, so that the magnetic strain generated when the leakage magnetic flux from the stationary induction coil flows in from the steel strip stacking surface facing the coil and flows in the longitudinal direction is defined as the vibrating force. Vibration can be prevented.

The invention according to claim 18 is a vertical magnetic shield in which a silicon steel strip is laminated on a tank surface of a stationary induction device so that the surface is vertical, and a silicon steel strip having a predetermined size is provided. A plurality of projections are formed at a narrow pitch by pressing the plate surface, and when the silicon steel strips are laminated, the projections of the upper silicon steel strip are formed in the recesses on the back side of the projections of the lower silicon steel strip. The convex portions are sequentially inserted, and these are caulked and integrated.

Therefore, according to the magnetic shield of the stationary induction device having the above-described configuration, the protrusion of the projection of one steel strip is pressed into the recess of the projection of the other steel strip to be integrated. The rigidity of the magnetic shield in the stacking direction increases, so that the leakage magnetic flux from the stationary induction coil flows in from the steel strip stacking surface side facing the coil, and the vibration generated by the magnetic strain generated when flowing in the longitudinal direction is used as the vibrating force. Can be prevented.

The invention according to claim 19 is a vertical magnetic shield in which a silicon steel strip is laminated on a tank surface of a stationary induction appliance so that the surface thereof is vertical, and the heat shrink tape or the self-fusing tape is formed at a narrow pitch. It is bound and integrated with a binding tape such as an attaching tape.

Therefore, according to the magnetic shield of the stationary induction device having the above-described configuration, when laminating the steel strip cut to a predetermined size or mounting the steel strip on the tank wall, the magnetic shield is narrow in the longitudinal direction of the magnetic shield. Because the pitch is integrated by binding with a binding tape such as a heat shrink tape or a self-fusing tape at the pitch, the rigidity of the magnetic shield in the laminating direction increases, so that the leakage magnetic flux from the stationary induction coil faces the coil. Vibration using magnetic strain generated when flowing in from the steel strip laminating surface side and flowing in the longitudinal direction can be prevented.

According to a twentieth aspect of the present invention, in a vertical magnetic shield in which a silicon steel strip is laminated on a tank surface of a stationary induction device so that the surface is vertical, the silicon steel strip has a predetermined size. When cutting, a notch is formed at a narrow pitch on the plate surface on the mounting surface side of the magnetic shield, and a steel plate bent in a U shape is fitted into the notch by shrink fitting or press fitting or the L-shaped steel plate is cut out. After being installed in the part, one side is bent and fitted to be integrated.

Therefore, according to the magnetic shield of the stationary induction device having the above-described configuration, a steel plate bent in a U-shape is fitted into a notch formed at a narrow pitch in the longitudinal direction of the magnetic shield by shrink fitting or press fitting. After fitting or by inserting an L-shaped steel plate into the notch, one side of the steel plate is bent and fitted and integrated, so that the rigidity of the magnetic shield in the laminating direction increases, and therefore, from the static induction coil. Can be prevented from flowing as a vibrating force due to the magnetic strain generated when the leakage magnetic flux flows from the steel strip lamination surface side facing the coil and flows in the longitudinal direction.

The invention corresponding to claim 21 is claim 17.
In the magnetic shield for a static induction device according to any one of claims 20 to 20, thick plates are arranged on both sides of the magnetic shield to be integrated.

Therefore, according to the magnetic shield of the stationary induction device having the above-described configuration, the rigidity in the steel strip laminating direction is further increased, and therefore, the leakage magnetic flux from the stationary induction coil is reduced to the side of the steel strip lamination surface facing the coil. , And vibrations generated by magnetostriction generated when flowing in the longitudinal direction can be prevented.

According to a twenty-second aspect of the present invention, there is provided a vertical magnetic shield in which a silicon steel strip is laminated on a tank surface of a stationary induction device so that the surface thereof is vertical, wherein a corrugated thin plate and the magnetic shield are formed. They are juxtaposed and the interval between the peaks of the corrugated thin plate is formed at a narrow pitch.

Therefore, according to the magnetic shield of the stationary induction device having the above-described structure, the vertical magnetic shield is pressed by the peak of the corrugated thin plate, that is, the vertical magnetic shield is constrained at every pitch. The rigidity in the laminating direction of the coil increases, so the leakage magnetic flux from the stationary induction coil will flow in from the lamination surface side of the steel strip facing the coil, and vibration generated by the magnetic strain generated when flowing in the longitudinal direction will be prevented. it can.

The invention corresponding to claim 23 is based on claim 22
In the magnetic shield of the stationary induction device described in the above, a spiral ring made of a thin plate is arranged in a space formed by the corrugated thin plate.

Therefore, according to the magnetic shield of the stationary induction device having the above-described configuration, the ring formed of the spiral thin plate is arranged so as to fill the gap formed by the thin corrugated plate. The pressure applied to the magnetic shield by the magnetic shield increases, and the pitch at which the magnetic shield is pressed can be reduced arbitrarily, so the rigidity of the magnetic shield in the laminating direction increases, so that the leakage magnetic flux from the stationary induction coil becomes opposite to the steel facing the coil. Vibration using the magnetic strain generated when flowing in from the band laminating surface side and flowing in the longitudinal direction can be prevented. Further, when a magnetic material is used for the corrugated thin plate and the spiral ring, the function of a magnetic shield can be imparted to them.

According to a twenty-fourth aspect of the present invention, in a vertical magnetic shield in which a silicon steel strip is laminated on a tank surface of a stationary induction device so that its surface is vertical, the tank wall on which the magnetic shield is mounted is concave. The magnetic shield is attached by pressing a magnetic shield into the concave portion of the tank wall.

Therefore, according to the above-described method of mounting the magnetic shield, the tank wall on which the magnetic shield is to be mounted is drawn into a concave shape, and the vertical magnetic shield is pressed into this concave portion and fixed. Since the shield is constrained by a substantially uniform pressure, the rigidity of the magnetic shield in the stacking direction increases, and the tank itself also increases in rigidity due to the formation of the throttle portion in the tank, and therefore leakage from the stationary induction coil. Magnetic flux flows in from the steel strip lamination surface side facing the coil, and vibration of the magnetic shield and the tank wall, which is caused by magnetic strain generated when flowing in the longitudinal direction, can be prevented.

The invention corresponding to claim 25 is the invention according to claim 24.
In the method of mounting a magnetic shield described in the above paragraph, the magnetic shield is mounted by interposing a damping steel plate between the magnetic shield pressed into the concavely drawn tank wall and the tank wall.

Therefore, according to the magnetic shield mounting method described above, when the magnetic shield according to the twenty-fourth aspect of the present invention is mounted, a vibration damping performance is provided between the tank wall and the magnetic shield press-fitted into the tank wall. Since the press-fitting is performed with the high damping steel plate interposed therebetween, it is possible to attenuate the vibrating force generated when the vibration of the magnetic shield is transmitted to the tank wall in direct contact.

According to a twenty-sixth aspect of the present invention, in a method of mounting a magnetic shield provided in a tank of a stationary induction device, a holding block made of a permanent magnet is fixed to a mounting surface side of the magnetic shield, Attach a magnetic shield by arranging a vibration isolating material on the surface that comes into contact with the shield or the mounting surface side.

Therefore, according to the above-described method of mounting the magnetic shield, when the holding block made of the permanent magnet fixed to the mounting surface side of the magnetic shield is mounted on a structure such as a tank wall, the magnetic excitation source is used. Since the shield and the structure do not directly contact each other and are fixed by the attraction force of the permanent magnet through the vibration isolator attached to the holding block, it is possible to attenuate the vibrating force transmitted to the tank wall. it can. In addition, even if the anti-vibration performance is not attached, the structure does not need a fixed structure dedicated to the shield, so that the mounting is easy and the mounting position can be arbitrarily set.

[0088]

Embodiments of the present invention will be described below with reference to the drawings.

The first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a partial view showing a corresponding positional relationship between a horizontal magnetic shield and a transformer coil, and FIG. 2 is a perspective view of the magnetic shield. As shown in FIG. 1, a magnetic shield 3 is provided at a position facing a transformer coil 2 wound around an iron core 1 inside a tank wall 4, and attached and fixed with fixing bolts 5.

As shown in FIG. 2, the magnetic shield 3 is provided with a magnetic shield portion in which a plurality of 6.5% silicon steel strips are stacked in parallel with the tank wall 4 with the side facing the transformer coil 2 as the front face. And a magnetic shield portion 7 in which a plurality of directional silicon steel strips are stacked on the rear surface thereof.

FIG. 1 shows a case where the horizontal magnetic shield 3 having the above-described configuration is disposed on the tank wall 4 corresponding to one surface of the transformer coil 2. Each of them is disposed so as to face the surface.

Next, the operation of the first embodiment configured as described above will be described.

When a load current flows through the transformer coil 2 wound around the iron core 1, a leakage magnetic flux Φ is generated from the transformer coil 2 and reaches the magnetic shield 3 fixed to the tank wall 4 by the fixing bolt 5. I do. The leakage magnetic flux Φ flows into the magnetic shield from the surface of the magnetic shield 3, flows in the longitudinal direction thereof, flows out of the surface of the magnetic shield 3, and returns to the transformer coil 2 again. In this case, when the leakage magnetic flux flows into or out of the surface of the magnetic shield 3, an electromotive force is applied to the surface of the magnetic shield, and an eddy current I flows in the surface.

Here, the eddy current I and the Joule loss W due to the eddy current are given by: I = kΦΦ / ρ W = k ・ Φ ² / ρ where k is a proportional constant. Therefore, a directional silicon steel strip having a low specific resistance ρ generates a large eddy current and loss.

Also, due to the reverse magnetic field due to the eddy current and the gap between the steel strip layers, the leakage magnetic flux cannot move quickly in the direction of lamination of the shield, and until the steel strips close to the surface can be allowed one by one, that is, magnetic saturation occurs. The magnetic flux continues to flow until the magnetic flux is saturated, and the magnetic flux moves to the next steel strip only at the time of magnetic saturation. Therefore, the magnetic flux density distribution in the laminating direction shows a rightward downward distribution from the coil facing side to the rear surface of the magnetic shield, and a certain number of steel strips on the surface are magnetically saturated.

In the first embodiment of the present invention, a magnetic shield portion 6 is used in which a 6.5% silicon steel strip is laminated on the steel strip in the magnetic saturation and magnetic asymptotic state. In addition, the amount is equivalent to the number within the range of 2% to the maximum of 22% of the total stacking amount of the shield depending on the model as a result of the test investigation (However, it is necessary to increase the amount by the ratio of the saturation magnetic flux density (13%). Is).

As shown in FIG. 3, the magnetic shield portion 6 having the 6.5% silicon steel strip laminated thereon has a high specific resistivity and a small saturation magnetostriction, so that the loss is reduced by half and the magnetostriction vibration is reduced by the above equation. It can be greatly reduced.

The leakage magnetic flux Φ flowing into the magnetic shield part 7 having the directional silicon band laminated on the rear surface of the shield is divided by the amount of magnetic flux that has flowed into the magnetic shield part 6 having the 6.5% silicon steel band laminated. Decreases, reduces losses, escapes magnetic saturation and saturation asymptotic conditions, and reduces magnetostrictive oscillations.
Generally, the magnetostriction of a directional silicon steel strip is very small if it escapes magnetic saturation and saturation asymptotics. Further, since the material itself is strongly bonded and fixed to the 6.5% silicon steel strip having high rigidity by resin bonding or the like, bending (flexure) vibration generated in a general magnetic shield hardly occurs. The magnetic permeability of the directional silicon steel strip is high, and the directional silicon steel strip magnetic shield portion 7 arranged on the rear surface attracts the leakage magnetic flux and prevents the magnetic flux from flowing into the tank wall 4.

Therefore, the shield body has both small loss and magnetostrictive vibration and a sufficient shielding effect.

Next, a second embodiment of the present invention will be described with reference to FIGS.

FIG. 4 is a partial view showing a corresponding positional relationship between a vertical magnetic shield and a transformer coil, and FIG. 5 is a perspective view of the magnetic shield. As shown in FIG. 4, a magnetic shield portion 9 having a bidirectional silicon steel strip surface vertically laminated at a position facing a transformer coil 2 wound around an iron core 1 inside a tank wall 4 is housed in a fixing channel 8. At the same time, the vertical magnetic shield 3 bundled with fixing bolts 5 is arranged in a hole formed in the steel strip, and the fixing channel 8 is fixed to the tank wall by welding or the like.

As shown in FIG. 5, the magnetic shield section 9 controls the inflow direction of the leakage magnetic flux Φ flowing from the transformer coil 2,
That is, the steel strip is arranged so that the direction perpendicular to the rolling direction of the bidirectional silicon steel strip coincides with the steel strip width direction from the steel strip lamination surface facing the coil to the opposite lamination surface.

FIG. 4 shows a case where the vertical magnetic shield 3 having the above-described structure is disposed on the tank wall 4 corresponding to one surface of the transformer coil 2. They are provided corresponding to each surface.

The operation of the second embodiment having the above configuration will be described.

When the vertical magnetic shield 3 is made of directional silicon steel, the direction of inflow of the leakage magnetic flux Φ from the transformer coil 2 is perpendicular to the rolling direction.

As shown in FIG. 3, the magnetic permeability in the perpendicular direction of the directional silicon steel strip is one digit smaller than that in the rolling direction, and extends from the lamination surface facing the coil of the vertical magnetic shield to the lamination surface on the opposite side. Leakage magnetic flux Φ is less likely to move in the steel strip width direction than in the longitudinal direction. Therefore, the leakage magnetic flux flowing into the vertical magnetic shield attempts to change the flow in the longitudinal direction, so even in the vertical magnetic shield, it is not as extreme as the horizontal magnetic shield, but as far as the steel strip lamination surface side facing the coil. A magnetic flux distribution is generated such that the magnetic flux density is higher than that on the opposite laminated surface side.

Therefore, in the magnetic shield part on the lamination surface side (width side) of the steel strip facing the coil, there are places where the magnetic saturation and the saturation asymptotic state occur, and the magnetostrictive vibration increases, and the iron loss also increases.

As in the second embodiment, the magnetic shield portion 9 made of a bidirectional silicon steel strip is used for the vertical magnetic shield 3 and one of the easy magnetization directions, ie, the magnetic permeability, as shown in FIG. When the direction perpendicular to the rolling direction with good loss is matched with the width direction of the steel strip from the lamination surface facing the coil to the lamination surface on the opposite side, the magnetic flux quickly spreads over the entire width direction, and also in the easy magnetization direction. It flows evenly in the longitudinal direction of the magnetic shield along a certain rolling direction. That is, the magnetic flux distribution becomes uniform, and the loss also decreases.

Next, a third embodiment of the present invention will be described with reference to FIG.

FIG. 6 is a perspective view of a vertical magnetic shield. In the magnetic shield 3 according to the third embodiment,
Magnetic shield portion in which 6.5% silicon steel strips are stacked on both sides of the steel strip stacking surface opposite to the coil of magnetic shield portion 7 in which the direction of leakage magnetic flux Φ flowing from the transformer coil is opposite, ie, the magnetic shield portion 7 in which directional silicon steel strips are stacked. 6 is arranged within the range of 2% to 15% of the total amount of lamination.

Next, the operation of the third embodiment configured as described above will be described.

In recent years, many devices that generate harmonics, such as rectifiers and induction furnaces, have been connected to transformer loads, and there have been cases where load currents containing harmonic components flow.
When the transformer has a large capacity, harmonic currents flowing from these various devices are collected, added up, and flow through the coil as a load current including a large harmonic current. In this case, the leakage magnetic flux generated from the coil naturally contains many harmonics, and when flowing into the magnetic shield, the magnetostriction and the magnetostrictive vibration also contain harmonic components. Therefore, the noise becomes audibly louder the higher the harmonics,
A small amount of harmonic components often poses a problem.

The vertical magnetic shield 3 according to the third embodiment of the present invention is provided in the inflow direction of the leakage magnetic flux Φ from the transformer coil, that is, on both sides of the steel strip lamination surface of the magnetic shield portion 7 facing the coil. 5. High permeability at high frequencies
Since the magnetic shield portion 6 made of a 5% silicon steel strip is arranged, the harmonic leakage magnetic flux Φh generated by the harmonic current flowing through the coil can reduce the magnetic permeability of the directional silicon steel strip whose permeability decreases at high frequencies. 6.5% with low saturation magnetostriction and high-frequency magnetic loss without flowing to the shield part 7
It almost flows to the magnetic shield part 7 made of a silicon steel strip. That is, the loss due to the harmonic leakage magnetic flux and the magnetostrictive vibration are reduced. Also,
By arranging the magnetic shield portions 6 on which the 6.5% silicon steel strips are laminated on both sides of the magnetic shield 7, the magnetostrictive vibration of the directional silicon steel strip placed at the center is restrained, and the rigidity is improved. , The soundproofing is enhanced.

Next, a fourth embodiment of the present invention will be described with reference to FIGS.

FIGS. 7 and 8 are perspective views of the magnetic shield. The magnetic shield 3 according to the fourth embodiment has a pair of magnetic shield portions 10 formed by laminating silicon steel strips bent in an L shape in the width direction so as to face inward,
A horizontal or vertical magnetic shield portion 3a is provided in the surrounding space.

Next, the operation of the fourth embodiment configured as described above will be described.

Generally, the magnetic shield is sufficiently longer in the longitudinal direction than its thickness and width. In this case, since the thin steel strips may be laminated, the bending rigidity in the longitudinal direction becomes extremely small. In addition, the leakage flux flows into the magnetic shield after turning in the longitudinal direction, so that magnetostriction and its vibration also occur in the longitudinal direction.

For this reason, the vibration using the magnetostriction as a vibrating force has a resonance point at a low frequency and is accompanied by complicated resonance vibration. As a result, the displacement amount due to the vibration becomes large.

Further, in the magnetic shield according to the fourth embodiment of the present invention, a pair of magnetic shield portions 10 formed by laminating silicon steel strips bent in an L-shape in the width direction are used in the magnetic shield laminating direction. High bending stiffness occurs, the resonance point rises, and magnetostrictive vibration can be suppressed.

Further, by providing the horizontal or vertical magnetic shield portion 3a in the surrounding space, the sectional area of the shield is increased, and the allowable leakage magnetic flux is increased.

When the horizontal magnetic shield 3a is used for the magnetic shield provided in the space surrounding the pair of magnetic shields 10, the shield width is narrower than that of the horizontal magnetic shield shown in FIG. As a result, the eddy current path generated in the magnetic field can be shortened (loss can be reduced), and the bias of the magnetic flux distribution in the stacking direction can be reduced. By adopting such a configuration, the bending deformation in the longitudinal direction caused by the magnetic shield is restrained, and the displacement can be reduced by about 30% as compared with the conventional configuration.

In the case of the fixing method shown in FIG. 7, a hole is formed in a steel strip forming the horizontal magnetic shield 3a, and a half-split is formed at a position corresponding to the lower side of the L-shaped magnetic shield 10. And fix it with bolts.

In the case of the configuration shown in FIG. 8, the L-shaped magnetic shields 10 do not necessarily have to be paired. That is, 1
The magnetic shield 3 having a desired size may be formed by combining an arbitrary number of the L-shaped magnetic shield portions 10 and the vertical magnetic shield portion 3a provided on the lower piece.

Next, a fifth embodiment of the present invention will be described with reference to FIG.

FIG. 9 is a perspective view of the magnetic shield. In the magnetic shield 3 according to the fifth embodiment, a pair of magnetic shield portions 10 formed by laminating silicon steel strips bent in an L shape in the width direction are opposed to each other outward, and both sides of a space on a lower side thereof. Similarly, a pair of horizontal or vertical magnetic shield portions 3b are arranged so as to be in contact with the L-shaped magnetic shield portion 10.

In this case, in order to fix the magnetic shield 3 having the structure as shown in FIG. 9, a hole is formed in a steel strip forming the horizontal magnetic shield 3b, and the lower side of the L-shaped magnetic shield 10 is supported. Make a hole in the same position and fix it with bolts.

Next, the operation of the fifth embodiment configured as described above will be described.

Generally, the length of the magnetic shield 3 in the longitudinal direction is sufficiently longer than its thickness and width. In that case,
Since thin steel strips may be laminated, the bending rigidity in the longitudinal direction becomes extremely small. Further, after the leakage magnetic flux flows into the magnetic shield 3, the leakage magnetic flux changes its direction in the longitudinal direction and flows.
Therefore, magnetostriction and its vibration also occur in the longitudinal direction.

For this reason, the vibration using the magnetostriction as the vibrating force has a resonance point at a low frequency and involves complicated resonance vibration. As a result, the displacement of the magnetic shield 3 due to the vibration increases.

In the fifth embodiment of the present invention, a high bending vibration is suppressed in the lamination direction of the magnetic shield by the pair of magnetic shield portions 10 formed by laminating silicon steel strips bent in an L shape in the width direction. doing. Further, by providing the horizontal magnetic shield part 3b on the lower side, the cross-sectional area of the shield is increased, and the allowable leakage magnetic flux is increased. In addition, 1
By making the pair of L-shaped magnetic shield portions 10 face outward, that is, by directing the lower sides thereof outward, the horizontal magnetic shield portions 3b disposed on the lower sides strictly have the lower side dimensions of the L-shaped magnetic shield portions 10. Does not have to be matched. That is, the width of the horizontal magnetic shield part 3b can be arbitrarily longer or shorter than the length of the lower side of the L-shaped magnetic shield 10.

The horizontal magnetic shield portion 3b provided on the lower side of the pair of magnetic shield portions 10 is generated in the plane because the shield width can be reduced to two or more divisions as compared with the horizontal magnetic shield shown in FIG. The eddy current path can be shortened (loss is reduced), and the bias of the magnetic flux distribution in the laminating direction can be reduced. With this configuration, bending deformation in the longitudinal direction generated by the magnetic shield is restrained, and the displacement can be reduced by about 30% as compared with the conventional configuration.

Next, a sixth embodiment of the present invention will be described with reference to FIGS.

FIGS. 10 and 11 are perspective views of the magnetic shield. In the sixth embodiment, a magnetic shield portion 1 is formed by laminating silicon steel strips bent in a U-shape in the width direction.
1 and a horizontal or vertical magnetic shield part 3 in the space surrounding it
a is provided and these are combined.

To fix the horizontal or vertical magnetic shield portion 3a to the U-shaped magnetic shield portion 11, in the case of the configuration shown in FIG. 10, a hole is formed in a steel strip forming the horizontal magnetic shield portion 3a. A hole is similarly formed in a corresponding position on the lower side of the magnetic shield portion 11 of the shape, and the magnetic shield portion 11 is fixed with a bolt.
In the case of the configuration shown in FIG.
Both the a and U-shaped magnetic shield portions 11 are provided with holes in their side surfaces and fixed with bolts. However, the same applies to the horizontal magnetic shield part, but the vertical magnetic shield part provided in the concave part is firmly fixed even with resin bonding, so it is not necessary to fix it with bolts, May be integrated.

The operation of the sixth embodiment configured as described above will be described.

In general, the magnetic shield is sufficiently longer in the longitudinal direction than its thickness and width. In this case, since the thin steel strips may be laminated, the bending rigidity in the longitudinal direction becomes extremely small. In addition, the leakage flux flows into the magnetic shield after turning in the longitudinal direction, so that magnetostriction and its vibration also occur in the longitudinal direction.

[0138] Therefore, the vibration generated by the magnetostriction as a vibrating force has a resonance point at a low frequency, and is accompanied by complicated resonance vibration. As a result, the displacement amount caused by the vibration of the magnetic shield becomes large.

In the sixth embodiment of the present invention, extremely high bending rigidity is achieved in the laminating direction of the magnetic shield portion 3a by the magnetic shield portion 11 formed by laminating silicon steel strips bent in a U-shape in the width direction. The resonance point is raised to suppress magnetostrictive vibration. Further, the horizontal or vertical magnetic shield portion 3a arranged so as to be filled in the surrounding space concave portion increases the shield cross-sectional area to increase the allowable leakage magnetic flux amount. As compared with the horizontal magnetic shield shown in FIG. 1, the narrower shield width can shorten the eddy current path generated in the plane (reduce the loss), and can also reduce the bias of the magnetic flux distribution in the stacking direction. According to this configuration, the bending deformation in the longitudinal direction generated by the magnetic shield is restrained, and the displacement can be reduced by about 40% as compared with the conventional configuration.

Next, a seventh embodiment of the present invention will be described with reference to FIG.

FIG. 12 is a perspective view of a magnetic shield. In the magnetic shield 3 according to the seventh embodiment, as shown in FIG. 12, a silicon steel strip is wound into a cylindrical shape and then elongated in an elliptical shape. A wound iron core type magnetic shield portion 12 is formed, and the outer peripheral surface thereof is opposed to a transformer coil.

In order to manufacture a magnetic shield having such a configuration, a rolled core obtained by winding a silicon steel strip in a round shape in the same manner as in the method of manufacturing a rolled core is pressed at an arbitrary position in a radial direction by pressing. The space (window) in the inner peripheral portion is crushed by pressing to form. In the configuration shown in FIG. 12, after being completely pressed by a press, it is fixed with a resin and fixed to the tank wall using a bolt hole formed near both ends of the long side.

The magnetic shield according to the seventh embodiment of the present invention is obtained by winding a silicon steel strip into a cylindrical shape, stretching the silicon steel strip into an elliptical shape, and pressing the opposing long-side axis sides so as to be in contact with each other. An iron core type magnetic shield 12 is manufactured, and its outer peripheral surface is opposed to the transformer coil as in the case of the horizontal type magnetic shield shown in FIG. 1. However, since the core is a wound core, both long sides of the magnetic shield are formed of a steel strip. The leakage magnetic flux that is continuous and flows into the long side on the side facing the transformer coil easily goes around to the long side on the tank side. Therefore, the magnetic flux distribution in the shield becomes uniform, and the loss and the magnetostrictive vibration are reduced.

Next, an eighth embodiment of the present invention will be described with reference to FIG.

FIG. 13 is a perspective view of the magnetic shield. The magnetic shield 3 according to the eighth embodiment, as shown in FIG. 13, winds a directional silicon steel strip in a cylindrical shape, expands it into an oblong shape, and presses the opposing long-side axis side to come into contact. To produce a wound iron core type magnetic shield 12,
As in the case of the vertical magnetic shield shown in FIG. 4, the laminated surface faces the transformer coil.

In order to manufacture a magnetic shield having such a configuration, a rolled core obtained by winding a silicon steel strip in a round form in the same manner as in the method of manufacturing a rolled core is pressed radially at an arbitrary position by pressing. The space (window) in the inner peripheral portion is crushed by pressing to form. In the configuration of FIG. 13, the holding ring 13 is previously formed and formed at the edge of the portion not pressed, and is fixed with resin or the like. The holding ring 13 is used for attaching to a tank wall or the like with the fixing bolt 5.

The magnetic shield according to the eighth embodiment of the present invention is manufactured by winding a silicon steel strip into a cylindrical shape, stretching the silicon steel strip into an elliptical shape, and pressing the opposing long-side axis sides into contact with each other. As shown in FIG. 3, the laminated surface faces the transformer coil, and the long sides facing each other have a continuous steel strip. As a result, the magnetic flux distribution in the shield becomes uniform, and the loss and the magnetostrictive vibration are reduced. Further, since the core is a wound core, the steel strip is continuous and can be fixed at an arc portion as shown in FIG. 13, so that the rigidity can be made relatively high and the mounting becomes easy.

Next, a ninth embodiment of the present invention will be described with reference to FIG.

FIG. 14 is a perspective view of the magnetic shield. In the ninth embodiment, as shown in FIG. 14, after winding a directional silicon steel strip in a cylindrical shape, it is stretched in an elliptical shape, and its opposing long-side axis side is pressed. An arbitrary amount of the horizontal magnetic shield portion 3a is arranged and combined on the inner peripheral portion thereof, and the laminated surface of the wound iron core magnetic shield 12 faces the transformer coil.

In this case, by arranging the horizontal magnetic shield 3a having a length corresponding to the long side of the wound iron core type magnetic shield 12, the magnetic flux is caught and flowed when the leakage magnetic flux flows in, thereby increasing the loss and increasing the loss. The transfer of magnetic flux in the laminating direction of the steel strip, which causes an increase in vibration, is minimized. Also, it is fixed to the tank wall using bolt holes drilled near both ends of the long side.

Therefore, the magnetic shield 3 having such a configuration
In, the leakage magnetic flux flowing into the long side facing the transformer coil easily wraps around the long side on the tank side, so the magnetic flux distribution in the stacking direction in the shield becomes uniform, reducing loss and magnetostrictive vibration. Is done. Also, in the magnetic shield, the magnetic flux leakage from the coil flows in from any part on the long side,
It flows while gathering in the longitudinal direction. As a result, the magnetic flux density in the longitudinal direction is greatly different, and a region having a locally high magnetic flux density exists near the center thereof, but in the inner peripheral portion (window portion) of the wound iron core type magnetic shield portion 12 corresponding to the region. By arranging the horizontal magnetic shield part 3a, the magnetic flux is divided, and the magnetic flux density in the longitudinal direction is made uniform by effectively increasing the cross-sectional area.

Next, a tenth embodiment of the present invention will be described with reference to FIG.

FIG. 15 is a perspective view of the magnetic shield. The magnetic shield 3 according to the tenth embodiment includes:
As shown in FIG. 15, after winding a directional silicon steel strip into a cylindrical shape, the wound core-type magnetic shield 12 is elongated in an oblong shape.
And a plate-shaped vertical magnetic shield portion 3a is disposed on the inner periphery thereof, and the laminated surface thereof is opposed to the transformer coil.

In this case, the plate-shaped vertical magnetic shield 3a having a length substantially corresponding to the long side of the wound iron core magnetic shield 12 is used.
By arranging, when the leakage magnetic flux flows in, the magnetic flux is captured and made to flow, thereby minimizing the transition of the magnetic flux in the lamination direction of the steel sheet, which causes an increase in loss and an increase in vibration. Positioning is easy.

Therefore, in the magnetic shield having such a configuration, the cross-sectional area of the magnetic shield faces the transformer coil, and the length of the facing magnetic shield part 12 of the wound core type magnetic shield 12 similarly to the vertical shield shown in FIG. Since the steel strip is continuous between the sides, the magnetic flux easily wraps around to the opposite long side. As a result, the magnetic flux distribution in the shield becomes uniform, and loss and magnetostrictive vibration are reduced. In the magnetic shield, the magnetic flux leaking from the coil flows in from all parts and flows while gathering in the longitudinal direction. As a result, the magnetic flux density in the longitudinal direction is greatly different, and a region having a locally high magnetic flux density exists near the center thereof, but a horizontal type is formed on the inner peripheral portion (window portion) of the wound iron core type magnetic shield 12 corresponding to the region. Magnetic shield part 3
By arranging a, the magnetic flux is diverted, and the magnetic flux density in the longitudinal direction is made uniform by effectively increasing the cross-sectional area.

Next, an eleventh embodiment of the present invention will be described with reference to FIG.

FIG. 16 is a perspective view of the magnetic shield. In the eleventh embodiment, as shown in FIG. 16, after winding a directional silicon steel strip into a cylindrical shape, a wound iron core type magnetic shield 12 formed and fixed to a desired size is wound around the entire circumference of the iron core 1. The magnetic shield is fixed on the clamp 14, and the laminated surface of the magnetic shield faces the coil 2.

In this case, in order to manufacture a vertical magnetic shield, the silicon steel strip is wound on a round winding form in which the entire circumference of the clamp around the iron core is made equal to the outer circumference in the same manner as in the manufacturing method of the wound iron core. Then, the wound iron core is pressed at an arbitrary position in a radial direction by a press to form a rectangular shape, and is fixed by a resin. Also, when the iron core is large and the manufacturing method as described above cannot be applied,
A steel strip is guided directly from a grain-oriented silicon steel sheet (raw material) onto a clamp, wound around a core, and wound to form a magnetic shield. In this case, after forming the shield, it is fixed by wedge driving or welding and fixed by resin application.

In the magnetic shield having such a structure, a vertical magnetic shield having a uniform magnetic flux distribution, a small loss, a relatively high rigidity such as a corner portion, and a small amount of magnetostriction vibration can be relatively easily formed. Can be mounted on a transformer.

Next, a twelfth embodiment of the present invention will be described with reference to FIG.

FIG. 17 is a perspective view of the magnetic shield. In the twelfth embodiment, as shown in FIG. 17, in the magnetic shield 3 arranged such that the lamination surface of the silicon steel strip faces the transformer coil, the width of the central portion is wider than the width of both ends. This constitutes a magnetic shield.

In this case, at both ends of the magnetic shield, pedestals 15 whose thickness is specified to be slightly thicker than the width of the widened magnetic shield are installed, and are fixed to the magnetic shield by welding. At that time, a sufficient space is provided between the portion (convex portion) of the magnetic shield having an increased plate width and the pedestal so that magnetic flux does not flow into the pedestal. The pedestal has bolt holes so that it can be attached to the tank wall as it is. In the figure, reference numeral 16 denotes a weld beat.

The use of a bidirectional silicon steel strip as the shielding material is more effective in making the magnetic flux density uniform than using a bidirectional silicon steel strip.

In the magnetic shield having such a structure, the magnetic flux leaking from the coil flows in from all parts,
It flows while gathering in the longitudinal direction. Accordingly, the magnetic flux density in the longitudinal direction is greatly different, and a region having a locally high magnetic flux density exists near the center.

According to the twelfth embodiment of the present invention, in the vertical magnetic shield in which the laminated surface of the silicon steel strip faces the transformer coil, the width of the central part is 10% of the width of both ends.
To increase the magnetic flux density by increasing the cross-sectional area of the central part of the magnetic shield, which can cause high magnetic flux density, thereby reducing iron loss and magnetostriction. Can be.

Next, a thirteenth embodiment of the present invention will be described.

In the magnetic shield, the magnetic flux leaking from the coil flows in from all parts and flows while gathering in the longitudinal direction. Therefore, in the leakage magnetic flux inflow portion, magnetic attraction acts perpendicularly to the shield surface, and magnetic flux flowing in the longitudinal direction causes magnetostriction. Especially in the horizontal magnetic shield, the lamination direction matches the direction in which the magnetic attraction force works,
As a result, the vibration is quite large.

In the thirteenth embodiment of the present invention, a thick directional silicon steel strip is used as the material of the magnetic shield. In general, a thick directional silicon steel strip has much larger magnetostriction in the material than a thin directional silicon steel strip. For example, the magnetostriction of a 0.5 mm thick material is about twice that of a 0.23 mm thick material. Therefore, when vibration and noise pose a problem, a thin directional silicon steel strip is generally employed. The present inventors have found that the vibration of the actual magnetic shield is reduced by about 30% in the case of the thick material. Since the magnetic shield exhibits a vibration mode based on bending vibration in the laminating direction, it is clear that a thick material having high bending stiffness, that is, a material having high bending rigidity exhibited good vibration and noise characteristics. As described above, it is more effective to reduce vibration and noise by using a thick material instead of using a thin material such as an iron core as a material of the magnetic shield.

Next, a fourteenth embodiment of the present invention will be described with reference to FIG.

FIG. 18 is a perspective view showing the structure of the magnetic shield.

In the horizontal magnetic shield, the leakage magnetic flux from the coil flows in from the surface of the steel strip and flows in the longitudinal direction while being gradually dispersed in the laminating direction. Therefore, in the leakage magnetic flux inflow portion, magnetic attraction acts perpendicularly to the shield surface, and magnetic flux flowing in the longitudinal direction causes magnetostriction. This magnetostriction is particularly large near the shield surface. In addition, since the shield is firmly fixed to the structure by bolts etc. at both ends in the longitudinal direction, the vibration due to the magnetostrictive vibration and the electromagnetic attractive force occurs in the same rigid weak lamination direction,
The vibration is quite large.

In the fourteenth embodiment according to the present invention, as shown in FIG. 18, on the surface of the horizontal magnetic shield 3 facing the transformer coil, the plate width is sufficiently smaller than the shield width.
A thick contact plate 17 having sufficient bending rigidity is installed along the longitudinal direction, and is fixed together with the shield by fixing bolts 5.

Therefore, it is possible to forcibly suppress the bending vibration generated in the shield lamination direction in the shield longitudinal direction. Also, while the vibration is maximum at the center between the fixing bolts, while the fixing of the contact plate 17 is only at both ends,
If the pressing plate 17 has a slight curvature so that the convex portion hits the central portion of the shield in order to make the pressing at the central portion more firm, the vibration suppressing effect is significantly increased. If chatter occurs between the shield and the shield, a vibration isolator may be provided at the interface between the shield and the shield.

Next, a fifteenth embodiment of the present invention will be described with reference to FIG.

FIG. 19 is a perspective view showing the structure of the magnetic shield.

When the leakage magnetic flux flows into or out of the surface of the magnetic shield, an electromotive force is applied to the surface of the magnetic shield, and an eddy current I flows in the surface. Due to the reverse magnetic field due to the eddy current, the leakage magnetic flux cannot move quickly in the shield lamination direction, and continues to flow until each steel strip close to the surface can be allowed, that is, until magnetic saturation is reached. For the first time, it takes a magnetized form in which magnetic flux moves to the next steel strip. Therefore, the magnetic flux density distribution in the laminating direction shows a right-down distribution from the coil-facing side of the magnetic shield to the rear surface, and the magnetostriction increases as the surface is closer to the surface.

In the fifteenth embodiment of the present invention, FIG.
As shown in the figure, a steel strip having one or more slits 18 formed on the surface of the magnetic shield 3 along the longitudinal direction is laminated.

Therefore, by forming such a slit 18, when the leakage magnetic flux penetrates in the laminating direction, the current path through which the eddy current generated in the plane should flow is cut off, so that the eddy current path can be reduced. That is, not only can the eddy current loss be reduced, but also the leakage magnetic flux does not need to receive the reverse magnetic field due to the eddy current, and can easily penetrate in the laminating direction.
The magnetic flux distribution in the stacking direction becomes uniform. Since this slit is provided to cut off eddy current,
It is better to reduce the slit width as much as possible by electric discharge machining. An excessively large slit width is not preferable because the effective cross-sectional area of the shield decreases and the allowable leakage magnetic flux decreases.

Next, a sixteenth embodiment of the present invention will be described with reference to FIG.

FIG. 20 is a perspective view showing the structure of the magnetic shield.

The leakage magnetic flux flows into the magnetic shield from the surface of the magnetic shield, flows in the longitudinal direction of the magnetic shield,
Furthermore, it follows a path that flows out of the surface of the magnetic shield and returns to the coil. Leakage magnetic flux cannot move quickly in the shield lamination direction due to the reverse magnetic field due to the eddy current generated in the plane and the gap between the steel strip layers, and until the steel strips close to the surface can be allowed one by one, that is, up to magnetic saturation It continues to flow and takes a magnetized form in which the magnetic flux moves to the next steel strip only at the time of magnetic saturation. Therefore, the magnetic flux density distribution in the laminating direction shows a right-down distribution from the coil-facing side of the magnetic shield to the rear surface, and a certain number of steel strips on the surface are in a magnetically saturated state, increasing magnetic saturation. .

In the magnetic shield 3 according to the sixteenth embodiment of the present invention, as shown in FIG. 20 (a), after winding a directional silicon steel strip into a cylindrical shape, one place is fixed with a jig. ,
Through the process of cutting and spreading at the symmetrical position. Then, since the perimeter is longer from the inner diameter side to the outer diameter side, the length of each of the cut and divided steel strips gradually increases, and a trapezoidal block as shown in FIG. Is done. Further, as shown in FIG. 20 (c), the trapezoidal inclined portion (the reduced thickness portion generated at the time of cutting) is bent inward to be flush with the surface facing the transformer coil. At both ends, both ends of the steel strip existing in the stacking direction of the shield are all arranged on the surface of the shield, that is, the surface facing the coil. That is, at both ends, the leakage magnetic flux can easily flow into any steel strip from both ends without receiving a reverse magnetic field due to the eddy current. For this reason,
The magnetic flux distribution in the stacking direction becomes uniform, so that the magnetostriction and the vibration due to it can be reduced.

By the way, in this vertical magnetic shield having good shield characteristics, its mounting and fixing are as shown in FIG.
As shown in (1), a method of fixing the pedestal 15 to the tank wall 4 after welding the magnetic shield 3 to the pedestal 15 is practical. However, since the welding fixation to the pedestal is performed by MIG welding, the magnetic shield made of a thin plate is easily deformed by the heat input at that time, so the pedestal can not be welded at a short pitch, and the pedestal is welded at wide intervals I needed to.

The present inventors verified the vibration state of the magnetic shield installed by this method. However, since the bending rigidity of the magnetic shield in the longitudinal direction is small, the vibration waveform contains many harmonics. It has been confirmed that the amplitude also reaches several tens of μm from several μm. Also, with respect to noise caused by the vibration, even though it is not as good as the horizontal magnetic shield, a loud noise such as chattering noise is generated. For this reason, the vertical magnetic shield needs to have a configuration that enhances binding and bending rigidity in the stacking direction.

Further, the present inventors restrained the lamination direction of the magnetic shield at an arbitrary interval, and measured the amplitude while changing the interval (pitch). The graph of FIG. 34 shows the measurement result. In the figure, the vertical axis represents the amplitude, and the horizontal axis represents the restricted interval (pitch). According to the experimental results, as the constrained interval is narrowed from 600 mm, the amplitude sharply decreases, but the decrease decreases from the interval around 350 mm,
The distance gradually decreases to 100 mm. In addition, interval 0mm
The amplitude limit value of the vibration extrapolated (dotted line) is only about 30% lower than the value at the interval of 350 mm.
At intervals of 350 mm or less, the effect of the constraint is not so significant.

Also, it has been confirmed that the noise measurement results have the same tendency. At this time, the frequency of the leakage magnetic flux waveform flowing through the magnetic shield is 50 Hz, and the magnetostrictive vibration generated in the shield is mainly 2n times higher harmonics. This condition is a general operation mode for power transformers. is there.

That is, in the case of a vertical magnetic shield in which the pedestal can only be welded at a general wide interval (this is common), the magnetic shield is restrained in the laminating direction at an interval of at least 300 mm, so that the transformer is Under the general operating conditions, the rigidity capable of suppressing the magnetostrictive vibration at a considerable rate can be provided.

The present invention has been made based on the results of this investigation, and as a result of actual verification, good vibration and noise results have been obtained.

Based on the results, some embodiments will be described below.

First, a seventeenth embodiment of the present invention will be described with reference to FIG.
1, FIG. 22, FIG. 23 and FIG.

FIG. 21 is a partial view showing the positional correspondence between the vertical magnetic shield and the transformer coil. 22 and FIG.
3 and FIG. 24 are perspective views each showing the configuration of the magnetic shield.

As shown in FIG. 21, when a load current flows through the coil 2 mounted on the iron core 1, a leakage magnetic flux Φ is generated from the coil 2, and the pedestal 15 is fixed to both ends of the magnetic shield by welding. 4 reaches the vertical magnetic shield 3 to which the base 15 is fixed by bolts. The leakage magnetic flux Φ flows into the magnetic shield from the surface of the magnetic shield facing the iron core 1, flows in the longitudinal direction of the magnetic shield, flows out of the surface of the magnetic shield facing the iron core 1, and returns to the coil again. follow. In general, the magnetic shield is sufficiently longer in the longitudinal direction than its thickness and width. In that case,
Since thin steel strips may be laminated, the bending rigidity in the laminating direction becomes extremely small. Further, the leakage flux flows in the longitudinal direction after flowing into the magnetic shield, so that magnetostriction occurs in the longitudinal direction, but vibration occurs in the laminating direction. For this reason, the vibration using the magnetostriction as a vibrating force has a resonance point at a low frequency, and is accompanied by complicated resonance vibration. As a result, the displacement amount accompanying the vibration of the magnetic shield increases.

According to the seventeenth embodiment of the present invention, FIG.
As shown in FIG.
Rigidity is obtained by welding by a method that has little thermal influence on the silicon steel strip, such as G welding or laser welding, forming and binding and integrating the beat 16.

In this case, the welding interval is set to 30 as described above.
By setting the thickness to 0 mm or less, the amplitude of vibration is greatly reduced.

It is to be noted that the influence of heat due to welding is minimized,
At the time of cutting, a W-shaped groove is provided in advance in the welded portion of the silicon steel strip forming a shield so as not to cause cracks or the like by pressing or the like, and welding is performed at the convex portion of the W-shaped groove.

According to this welding method, the heat-affected zone at the time of welding falls within a range of 2 to 3 mm from the W-shaped groove convex portion, and thermal strain does not deteriorate the magnetic permeability of the magnetic shield. This is also effective in degassing, so that the occurrence of voids or cracks in the weld bead can be prevented. After the magnetic shield is integrated in this manner, the pedestals 15 are applied to both ends, and the pedestals 15 are attached by MIG welding.

Since welding needs to be performed on one side (the mounting surface side) of the magnetic shield, so-called one-sided tightening is performed, and the non-mounting surface side of the magnetic shield is in a free state, possibly causing vibration in the laminating direction. Sometimes.

In the embodiment shown in FIG. 22, in order to prevent the above-described vibration, the leakage magnetic flux does not interlink or flow.
That is, both ends of the magnetic shield or the end faces thereof, which do not form a short circuit, are also subjected to TIG welding so as to be restrained and integrated also on the side opposite to the mounting surface.

FIG. 23 shows another example in which a resin adhesive is used. As shown in FIG. 23, the pedestal is welded and fixed to both ends of the magnetic shield 3, and in this state, the pedestal is further fixed to the tank wall 4 by bolts and installed. Then, a resin or an adhesive (generally, epoxy resin is used) 19)
Is partially applied, penetrated in the laminating direction, cured, and integrated to provide rigidity. When a resin or an adhesive is applied to the entire magnetic shield, a contraction stress is applied to the entire magnetic shield at the time of curing, and this stress lowers the magnetic permeability and degrades the magnetic shield characteristics.

In this embodiment, the amplitude of the vibration is largely reduced as described above by setting the coating interval to 300 mm or less. Further, since the coating is not performed on the entire surface of the shield but is partial, the contraction stress hardly causes deterioration of the magnetic permeability, and does not accompany the deterioration of the shield characteristics.

FIG. 24 shows another example different from the above, in which spot welding is used. As shown in FIG. 24, when the silicon steel strip is cut into a predetermined size from the ring state (raw material), and when the steel strips are laminated, they are welded to the steel strip surface at intervals of 300 mm or less by spot welding (resistance welding) 20. To increase the rigidity of the magnetic shield 3 in the stacking direction. Spot welding requires enough energy to break the resin coating and the glass coating baked on the silicon steel strip surface, but the formed surface is smooth, the binding strength is large, and the rigidity is significantly improved.

However, on the other hand, the resistance between the silicon steel strip layers is low, and therefore the spot welding position must be as close as possible to the mounting surface side. In the example shown in FIG. 24, the protrusion is formed at a position close to the mounting surface side.

As described above, according to the magnetic shield to which the seventeenth embodiment of the present invention is applied, when the leakage magnetic flux from the transformer coil flows in from the steel strip lamination surface side facing the coil and flows in the longitudinal direction. Since the vibration using the magnetostriction generated in the vibrating force can be prevented, the effect of integration is exhibited, and as a result, the effect of reducing vibration and noise is remarkable.

Next, an eighteenth embodiment of the present invention will be described with reference to FIG.

FIG. 25 is a perspective view showing a configuration example of the magnetic shield.

In general, the magnetic shield is sufficiently longer in the longitudinal direction than its thickness and width. In this case, since the thin steel strips may be laminated, the bending rigidity in the longitudinal direction becomes extremely small. In addition, the leakage flux flows into the magnetic shield after turning in the longitudinal direction, so that magnetostriction and its vibration also occur in the longitudinal direction.

[0207] Therefore, the vibration using the magnetostriction as a vibrating force has a resonance point at a low frequency, and is accompanied by complicated resonance vibration. As a result, the displacement caused by the vibration of the magnetic shield becomes large.

In the eighteenth embodiment of the present invention, FIG.
When the silicon steel strip is cut into a predetermined size from the ring state (raw material) as shown in (1), projections 21 are formed at intervals of 300 mm or less on the surface of the steel strip by pressing or the like at the same time. The steel shields are stacked together and swaged, that is, the projections of one of the steel strips are pressed into the recesses formed on the back side of the projections of the other steel strip to be integrated to form the magnetic shield 3. The rigidity in the laminating direction is increased. Observing the cross section of the projection, when the projection is punched by a press, the resin coating and the glass coating baked on the surface of the silicon steel strip are caught in the side surface of the projection and serve as a lubricant to perform smooth crimping.

The resin coating and the glass coating have high electrical insulation properties, and the contact resistance between the metal of the protruding projection and the protruding protruding part on the other side is not small.
The contact resistance between the steel strip layers is sufficiently high. Therefore, the formation position of the protruding portion, that is, the caulking position may be at the center of the magnetic shield having the highest rigidity, or may be formed in a plurality of rows in the steel strip width direction.

However, considering long-term use, there is a concern that the insulation of the resin coating may be deteriorated, the contact resistance may be reduced due to peeling due to vibration, and the loss may be increased due to short-circuit of leakage magnetic flux. It is better to form a single row on the mounting surface side. In the embodiment of FIG. 25, the protrusions are formed in a single row on the mounting surface side.

As described above, according to the magnetic shield of the eighteenth embodiment of the present invention, the magnetic flux generated from the transformer coil is generated when the magnetic flux leaks in from the steel strip lamination surface side facing the coil and flows in the longitudinal direction. Since the vibration using the magnetostriction as a vibrating force can be prevented, the effect of integration is exhibited, and as a result, the effect of reducing vibration and noise is remarkable.

Next, a nineteenth embodiment of the present invention will be described with reference to FIG.

FIGS. 26A and 26B are perspective views showing a configuration example of the magnetic shield.

Generally, the magnetic shield is sufficiently longer in the longitudinal direction than its thickness and width. In this case, since the thin steel strips may be laminated, the bending rigidity in the longitudinal direction becomes extremely small. Furthermore, the leakage flux flows into the magnetic shield and then turns around in the longitudinal direction, so that magnetostriction occurs in the longitudinal direction, but vibration occurs in the stacking direction. For this reason, the vibration using the magnetostriction as a vibrating force has a resonance point at a low frequency, and is accompanied by complicated resonance vibration. As a result, the displacement amount accompanying the vibration of the magnetic shield increases.

In the nineteenth embodiment of the present invention, FIG.
When laminating the steel strip after cutting the silicon steel strip to a predetermined size from the ring state (raw material) as shown in the above, or when attaching it to the tank wall, heat shrink at intervals of 300 mm or less in the longitudinal direction of the magnetic shield 3. The magnetic shield is restrained and integrated with a bind tape 22 such as a tape (such as a balcon tape) to increase the rigidity of the magnetic shield in the longitudinal direction. In the drawing, reference numeral 15 denotes a pedestal.

Since the binding tape 22 is wound around the magnetic shield, the restraining force is uniformly applied to the entire shield, so that the so-called one-sided tightening prevents the magnetic shield from being restrained on the side opposite to the mounting surface, and vibration in the laminating direction. Can be suppressed.

In FIG. 26 (a), the bind tape is wrapped and bound at right angles to the plate surface at arbitrary intervals. In FIG. 26 (b), the bind tape is spirally wound in the longitudinal direction of the magnetic shield. Restrained.

The constraining method of FIG. 26B cannot make the convergence force at the constrained portion equal to that of the constraining method of FIG. It can be further reduced.

As described above, according to the magnetic shield of the nineteenth embodiment of the present invention, the leakage magnetic flux from the transformer coil flows in from the steel strip lamination surface side facing the coil and is generated when flowing in the longitudinal direction. Since the vibration using the magnetostriction as a vibrating force can be prevented, the effect of integration is exhibited, and as a result, the effect of reducing vibration and noise is remarkable.

Next, a twentieth embodiment of the present invention will be described with reference to FIG.

FIG. 27 is a perspective view showing a configuration example of the magnetic shield.

In general, the magnetic shield is sufficiently longer in the longitudinal direction than its thickness and width. In this case, since the thin steel strips may be laminated, the bending rigidity in the longitudinal direction becomes extremely small. Furthermore, the leakage flux flows into the magnetic shield and then turns around in the longitudinal direction, so that magnetostriction occurs in the longitudinal direction, but vibration occurs in the stacking direction. For this reason, the vibration using the magnetostriction as a vibrating force has a resonance point at a low frequency, and is accompanied by complicated resonance vibration. As a result, the displacement amount accompanying the vibration of the magnetic shield increases.

In the twentieth embodiment of the present invention, FIG.
When laminating steel strips after cutting silicon steel strips from a ring state (material) to predetermined dimensions as shown in (1), notches 23 are formed by pressing or the like at intervals of 300 mm or less in the longitudinal direction of the magnetic shield 3. A steel plate 24 bent into a U shape is fitted into the notch portion 23 by shrink fitting or press fitting, or an L-shaped steel plate 25 is fitted into the notch portion 23, and then one side of the steel plate is folded by pressing or the like. By bending, fitting and integrating, the rigidity of the magnetic shield in the stacking direction is increased.

In this case, a magnetic material is preferably used as a clamp material for the steel plate 24 in order to compensate for a reduction in the shield cross-sectional area at the notch of the steel strip. The length of the bent portion of the clamp is preferably set so as to reach a position longer than the center position of the shield width so that the magnetic shield can be pressed and restrained more uniformly. In the twentieth embodiment shown in FIG. 27, the magnetic shield is aligned with the surface opposite to the mounting surface. Although not shown in the drawings, a threaded tap may be formed on the steel plate 24 so that the steel plate 24 can be fixed to the mounting portion of the tank wall by bolting.

As described above, according to the magnetic shield of the twentieth embodiment of the present invention, when the magnetic flux leaking from the transformer coil flows in from the lamination surface side of the steel strip facing the coil and flows in the longitudinal direction, it is generated. Since the vibration using the magnetostriction as a vibrating force can be prevented, the effect of integration is exhibited, and as a result, the effect of reducing vibration and noise is remarkable.

Next, a twenty-first embodiment of the present invention will be described with reference to FIG.

FIG. 28 is a perspective view showing a configuration example of the magnetic shield.

In general, the magnetic shield is sufficiently longer in the longitudinal direction than its thickness and width. In this case, since the thin steel strips may be laminated, the bending rigidity in the longitudinal direction becomes extremely small. Furthermore, the leakage flux flows into the magnetic shield and then turns around in the longitudinal direction, so that magnetostriction occurs in the longitudinal direction, but vibration occurs in the stacking direction. For this reason, the vibration using the magnetostriction as a vibrating force has a resonance point at a low frequency, and is accompanied by complicated resonance vibration. As a result, the displacement amount accompanying the vibration of the magnetic shield increases.

In the twenty-first embodiment of the present invention, FIG.
As shown in FIG. 1, thick and highly rigid contact plates 17 are arranged at both ends thereof, and an integration process is performed to suppress vibration in the laminating direction. Other configurations are the same as those in FIG. 22, and the description thereof is omitted here.

The vertical magnetic shields described in the seventeenth to twentieth embodiments described above partially increase the rigidity by integrally integrating the laminated body. If you want to reduce noise, place this plate at both ends of the magnetic shield and integrate it with the laminated magnetic shield,
Effectively, rigidity is increased, and vibration can be reduced.

FIG. 28 shows an embodiment of the integration process by welding.
A groove is provided, and welding is performed at the convex portion of the W-shaped groove. Therefore, a large heat capacity is not required, and welding can be performed by TIG welding like a silicon steel strip.

As described above, according to the magnetic shield of the twenty-first embodiment of the present invention, when the magnetic flux leaking from the transformer coil flows in from the steel strip lamination surface side facing the coil and flows in the longitudinal direction, it is generated. This can prevent vibrations that use the generated magnetostriction as a vibrating force.

Next, a twenty-second embodiment of the present invention will be described with reference to FIG.

FIG. 29 is a perspective view showing a configuration example of the magnetic shield.

In general, the magnetic shield is sufficiently longer in the longitudinal direction than its thickness and width. In this case, since the thin steel strips may be laminated, the bending rigidity in the longitudinal direction becomes extremely small. Furthermore, the leakage flux flows into the magnetic shield and then turns around in the longitudinal direction, so that magnetostriction occurs in the longitudinal direction, but vibration occurs in the stacking direction. For this reason, the vibration using the magnetostriction as a vibrating force has a resonance point at a low frequency, and is accompanied by complicated resonance vibration. As a result, the displacement amount accompanying the vibration of the magnetic shield increases.

In the twenty-second embodiment of the present invention, FIG.
As shown in FIG. 7, the vertical magnetic shield 3 is juxtaposed with a thin plate (hereinafter referred to as a corrugated plate) 26 having a waveform and a high elastic force, and the interval (pitch) between the peaks of the corrugated plate is formed to be 300 mm or less. The rigidity of the magnetic shield in the stacking direction is improved by constraining the magnetic shield at every pitch by contact pressure of the corrugated sheet peaks. In this case, the material used for the corrugated sheet is preferably a magnetic material in order to also have the effect of a magnetic shield, but if the material itself causes a magnetostrictive vibration and becomes a problem, a non-magnetic material such as SUS304 is used. Materials need to be used.

As described above, according to the magnetic shield of the twenty-second embodiment of the present invention, the leakage magnetic flux from the transformer coil is generated when the magnetic flux flows in from the steel strip lamination surface side facing the coil and flows in the longitudinal direction. Since it is possible to prevent vibrations caused by magnetostriction as a vibrating force, the effect of integration is exhibited, and as a result, the effect of reducing vibration and noise is remarkably exhibited, and as a result, the effect of reducing vibration and noise is remarkably exhibited.

Next, a twenty-third embodiment of the present invention will be described with reference to FIG.

FIG. 30 is a perspective view showing a configuration example of the magnetic shield.

In general, the magnetic shield is sufficiently longer in the longitudinal direction than its thickness and width. In this case, since the thin steel strips may be laminated, the bending rigidity in the longitudinal direction becomes extremely small. Furthermore, the leakage flux flows into the magnetic shield and then turns around in the longitudinal direction, so that magnetostriction occurs in the longitudinal direction, but vibration occurs in the stacking direction. For this reason, the vibration using the magnetostriction as a vibrating force has a resonance point at a low frequency, and is accompanied by complicated resonance vibration. As a result, the displacement amount accompanying the vibration of the magnetic shield increases.

In the twenty-third embodiment of the present invention, FIG.
In the magnetic shield according to the twenty-second embodiment described above, in the gap formed by the corrugated sheet 26 (valley of the corrugated sheet),
A ring 27 made of a thin plate having a spiral elastic force is arranged to fill the gap.

With such a configuration, the pressing force on the vertical magnetic shield 3 due to the peaks of the corrugated sheet is increased, or the pitch for arbitrarily pressing the magnetic shield is reduced, and the rigidity of the magnetic shield in the stacking direction is improved. I do. When vibration (so-called chattering) of the magnetic shield in the lamination direction of the steel strip occurs, by disposing the ring at the peak of the corrugated sheet, the constraint interval of the magnetic shield is reduced (pitch is reduced), and the rigidity is further increased. It can increase the vibration reduction effect. In addition, when a magnetic material is used for the corrugated thin plate and the spiral ring, the magnetic shield function can be imparted to them. However, when the generated magnetostrictive vibration is a problem, it is necessary to use a non-magnetic material such as SUS304.

As described above, according to the magnetic shield of the twenty-third embodiment of the present invention, the magnetic flux generated from the transformer coil is generated when the magnetic flux leaks from the lamination surface side facing the coil and flows in the longitudinal direction. Since it is possible to prevent vibrations caused by magnetostriction as a vibrating force, the effect of integration is exhibited, and as a result, the effect of reducing vibration and noise is remarkably exhibited, and as a result, the effect of reducing vibration and noise is remarkably exhibited.

Next, a twenty-fourth embodiment of the present invention will be described with reference to FIG.

FIG. 31 is a perspective view showing a configuration example of the magnetic shield.

In general, the magnetic shield is sufficiently longer in the longitudinal direction than its thickness and width. In this case, since the thin steel strips may be laminated, the bending rigidity in the longitudinal direction becomes extremely small. Furthermore, the leakage flux flows into the magnetic shield and then turns around in the longitudinal direction, so that magnetostriction occurs in the longitudinal direction, but vibration occurs in the stacking direction. For this reason, the vibration using the magnetostriction as a vibrating force has a resonance point at a low frequency, and is accompanied by complicated resonance vibration. As a result, the displacement amount accompanying the vibration of the magnetic shield increases. Further, the magnetostrictive vibration of the magnetic shield is transmitted to the tank wall as it is, and also acts as a vibrating force for vibrating the tank wall. That is, the vibration is transmitted to the outside of the tank through the tank wall, and not only generates noise, but also vibrates the tank wall itself to generate noise. Further, when the tank wall has a soft structure, unexpected vibration and noise are caused due to resonance of the tank wall and the like.

In the twenty-fourth embodiment of the present invention, FIG.
As shown in (1), the tank wall 4 is previously drawn into a concave shape, and the vertical magnetic shield 3 is press-fitted into the concave portion and fixed.

Therefore, since the magnetic shield is restrained by the tank wall at a substantially uniform pressure, the rigidity of the magnetic shield in the stacking direction is increased, and the throttle portion is formed on the tank wall along the magnetic shield. The tank itself can also provide rigidity in the direction of vibration of the magnetic shield. In other words, the leakage and magnetic flux from the transformer coil flows in from the steel strip laminating surface side facing the coil, and the vibration and resonance of the magnetic shield and the tank wall, which are caused by the magnetic strain generated when flowing in the longitudinal direction, are prevented. it can.

Next, a twenty-fifth embodiment of the present invention will be described with reference to FIG.

FIG. 32 is a perspective view showing a configuration example of a magnetic shield.

Generally, the magnetic shield is sufficiently longer in the longitudinal direction than its thickness and width. In this case, since the thin steel strips may be laminated, the bending rigidity in the longitudinal direction becomes extremely small. Furthermore, the leakage flux flows into the magnetic shield and then turns around in the longitudinal direction, so that magnetostriction occurs in the longitudinal direction, but vibration occurs in the stacking direction. For this reason, the vibration using the magnetostriction as a vibrating force has a resonance point at a low frequency, and is accompanied by complicated resonance vibration. As a result, the displacement amount accompanying the vibration of the magnetic shield increases. Further, the magnetostrictive vibration of the magnetic shield is transmitted to the tank wall as it is, and also acts as a vibrating force for vibrating the tank wall. That is, the vibration is transmitted to the outside of the tank through the tank wall, and not only generates noise, but also vibrates the tank wall itself to generate noise. Further, when the tank wall has a soft structure, unexpected vibration and noise are caused due to resonance of the tank wall and the like.

In the twenty-fifth embodiment of the present invention, FIG.
In the method of attaching the magnetic shield according to the twenty-fourth embodiment, the vibration damping performance having a high vibration damping performance is provided between the tank wall 4 and the vertical magnetic shield 3 which is press-fitted into the tank wall (interface) as shown in FIG. Since the press-fitting is performed via the high damping steel plate 28, when the vibration of the magnetic shield is transmitted to the tank wall which is in direct contact, the vibrating force can be greatly reduced. That is, since most of the magnetostriction vibration amount of the magnetic shield is not transmitted to the tank wall, not only the vibration of the magnetic shield but also the vibration of the tank wall using the vibrating force can be greatly reduced. .

Next, a twenty-sixth embodiment of the present invention will be described with reference to FIG.

FIG. 33 is a perspective view showing a configuration example for explaining a method of attaching and fixing a magnetic shield.

In general, the magnetic shield is sufficiently longer in the longitudinal direction than its thickness and width. In this case, since the thin steel strips may be laminated, the bending rigidity in the longitudinal direction becomes extremely small. Furthermore, the leakage flux flows into the magnetic shield and then turns around in the longitudinal direction, so that magnetostriction occurs in the longitudinal direction, but vibration occurs in the stacking direction. For this reason, the vibration using the magnetostriction as a vibrating force has a resonance point at a low frequency, and is accompanied by complicated resonance vibration. As a result, the displacement amount accompanying the vibration of the magnetic shield increases. Further, the magnetostrictive vibration of the magnetic shield is transmitted to the tank wall as it is, and also acts as a vibrating force for vibrating the tank wall. That is, the vibration is transmitted to the outside of the tank through the tank wall, and not only generates noise, but also vibrates the tank wall itself to generate noise. Further, when the tank wall has a soft structure, unexpected vibration and noise are caused due to resonance of the tank wall and the like.

In the twenty-sixth embodiment of the present invention, FIG.
As shown in (1), a holding block 29 made of a permanent magnet is directly installed on the mounting surface side of the magnetic shield or fixed by resin bonding or the like, and is mounted on a structure such as the tank wall 4. In this case, the magnetic shield is fixed to the tank wall 4 by the attractive force of the permanent magnet, and does not require any fixing equipment.

Therefore, it is not necessary to provide an additional structure for fixing the magnetic shield to the tank or the like, and it is not necessary to provide a fixing portion such as a bolt hole in the magnetic shield itself. This facilitates the mounting to the tank, increases the arbitrariness of the mounting position, and simplifies the structure of the magnetic shield, as well as reducing the effective cross-sectional area by installing fixing bolt holes, for example. The effect is obtained that the reduction can be avoided, that is, the allowable amount of the leakage magnetic flux can be kept high.

The magnet has high energy (that is, a large attractive force) and has a magnetic permeability close to 1, for example, NeFeB
It is good to use a magnet. If the magnetic permeability is close to 1, the magnet is the same as the air layer, and there is no fear that the leakage magnetic flux flows into a structure such as a tank through the magnet.

The surface of the holding block 29 which is in contact with the tank wall 4 is made of a vibration isolating sheet
By affixing 0, direct contact between the magnetic shield 3 as a vibrating force and the structure is avoided, and the magnetic shield is fixed by the attractive force of the permanent magnet via the vibration isolator attached to the holding block. Therefore, the vibrating force transmitted to the tank wall can be reduced.

That is, since most of the magnetostrictive vibration of the magnetic shield is not transmitted to the tank wall, not only the vibration of the magnetic shield but also the vibration of the tank wall using the vibrating force is greatly reduced. You can do it.

In each of the embodiments described above, the magnetic shield of the transformer has been described. However, the magnetic shield of another stationary induction device such as a current transformer can be similarly applied and implemented.

[0262]

As described above, according to the present invention, the magnetic flux distribution of the magnetic shield of the stationary induction device is improved, and the rigidity of the magnetic shield in the laminating direction where the rigidity is weak is improved, which is one of the factors of the conduction noise. It is possible to provide a magnetic shield for a stationary induction device and a method for mounting the same, which can reduce a magnetostrictive vibration of a certain magnetic shield and remove the magnetic shield vibration from a factor of generating noise.

[Brief description of the drawings]

FIG. 1 is a partial view showing a corresponding positional relationship between a horizontal magnetic shield and a transformer coil for describing a first embodiment of the present invention.

FIG. 2 is a perspective view showing a configuration of a magnetic shield according to the first embodiment of the present invention.

FIG. 3 is a view for explaining material properties of various silicon steel strips.

FIG. 4 is a partial view showing a corresponding positional relationship between a vertical magnetic shield and a transformer coil for describing a second embodiment of the present invention.

FIG. 5 is a perspective view showing a configuration of a magnetic shield according to a second embodiment of the present invention.

FIG. 6 is a perspective view of a magnetic shield according to a third embodiment of the present invention.

FIG. 7 is a perspective view of a horizontal magnetic shield according to a fourth embodiment of the present invention.

FIG. 8 is a perspective view of a vertical magnetic shield according to a fourth embodiment of the present invention.

FIG. 9 is a perspective view of a magnetic shield according to a fifth embodiment of the present invention.

FIG. 10 is a perspective view of a horizontal magnetic shield according to a sixth embodiment of the present invention.

FIG. 11 is a perspective view of a vertical magnetic shield according to a sixth embodiment of the present invention.

FIG. 12 is a perspective view of a magnetic shield according to a seventh embodiment of the present invention.

FIG. 13 is a perspective view of a magnetic shield according to an eighth embodiment of the present invention.

FIG. 14 is a perspective view of a magnetic shield according to a ninth embodiment of the present invention.

FIG. 15 is a perspective view of a magnetic shield according to a tenth embodiment of the present invention.

FIG. 16 is a configuration diagram of a transformer to which a magnetic shield according to an eleventh embodiment of the present invention is applied.

FIG. 17 is a perspective view of a magnetic shield according to a twelfth embodiment of the present invention.

FIG. 18 is a perspective view of a magnetic shield according to a fourteenth embodiment of the present invention.

FIG. 19 is a perspective view of a magnetic shield according to a fifteenth embodiment of the present invention.

FIGS. 20A to 20C are perspective views of a magnetic shield showing a sixteenth embodiment of the present invention.

FIG. 21 is a partial view for explaining a positional correspondence between a vertical magnetic shield and a transformer coil according to a seventeenth embodiment of the present invention.

FIG. 22 is a perspective view showing a magnetic shield according to a seventeenth embodiment of the present invention.

FIG. 23 is a perspective view showing another magnetic shield according to the seventeenth embodiment of the present invention.

FIG. 24 is a perspective view showing still another magnetic shield according to the seventeenth embodiment of the present invention.

FIG. 25 is a perspective view of a magnetic shield according to an eighteenth embodiment of the present invention.

FIGS. 26A and 26B are perspective views of a magnetic shield showing a nineteenth embodiment of the present invention.

FIG. 27 is a perspective view of a magnetic shield according to a twentieth embodiment of the present invention.

FIG. 28 is a perspective view of a magnetic shield according to a twenty-first embodiment of the present invention.

FIG. 29 is a perspective view of a magnetic shield according to a twenty-second embodiment of the present invention.

FIG. 30 is a perspective view of a magnetic shield according to a twenty-third embodiment of the present invention.

FIG. 31 is a perspective view of a magnetic shield according to a twenty-fourth embodiment of the present invention.

FIG. 32 is a perspective view of a magnetic shield according to a twenty-fifth embodiment of the present invention.

FIG. 33 is a perspective view of a magnetic shield according to a twenty-sixth embodiment of the present invention.

FIG. 34 is a diagram showing the result of measuring the amplitude of vibration while changing the stacking direction of the vertical magnetic shield and changing the interval (pitch) thereof.

FIG. 35 is a perspective view illustrating a configuration example of a transformer to which a conventional magnetic shield is attached.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Iron core 2 ... Coil 3 ... Magnetic shield 4 ... Tank wall 5 ... Fixing bolt 6 ... 6.5% silicon steel strip magnetic shield part 7 ... Directional silicon steel band magnetic shield part 8 ... fixing channel 9 ... magnetic shield part made of bidirectional silicon steel strip 10 ... L-shaped magnetic shield part 11 ... U-shaped magnetic shield 12 ... wound iron core type magnetic shield 13 ... holding ring, 14 ... … Clamp 15… Pedestal 16… Welded part beat 17… Contact plate 18… Slit 19… Resin adhesive 20… Spot welding 21… Protrusion 22… Bind tape 23… Notch 24… U-shaped steel sheet 25 L-shaped steel sheet 26 Corrugated sheet 27 Vortex ring 28 Damping steel sheet 29 Permanent magnet holding block 30 Vibration-proof sheet

Claims (26)

[Claims] 1. A horizontal magnetic shield in which a silicon steel strip is laminated on a tank surface of a stationary induction device so that its surface is parallel to the tank surface, and a plurality of 6.5% silicon is provided on a front surface facing the stationary induction device coil. A magnetic shield for a stationary induction appliance, wherein steel strips are stacked and arranged, and a directional silicon steel strip is stacked and stacked on a rear surface. 2. A vertical magnetic shield comprising a silicon steel strip laminated on a tank surface of a stationary induction electric appliance so that its surface is vertical, and a two-way silicon having an easy axis of magnetization in a rolling direction and a direction perpendicular to the rolling direction. A magnetic shield for a stationary induction device, characterized by using a steel strip material. 3. A vertical magnetic shield in which a silicon steel strip is laminated on a tank surface of a stationary induction appliance so that the surface thereof is vertical, and a plurality of 6.5% silicon steel strips are provided on both sides of the laminated portion. A magnetic shield for a stationary induction device, wherein a magnetic induction shield is provided. 4. A magnetic shield installed on a tank surface of a stationary induction device, wherein a pair of magnetic shield members formed by laminating silicon steel strips bent in an L-shape in the width direction are inwardly opposed to each other, and a space surrounding the pair. A magnetic shield for a stationary induction machine, characterized in that a magnetic shield member is provided on the magnetic shield. 5. A magnetic shield installed on a tank surface of a stationary induction device, wherein a pair of magnetic shield members formed by laminating silicon steel strips bent in an L-shape in the width direction are outwardly opposed to each other, and on both sides thereof. A magnetic shield for a stationary induction device, wherein a pair of magnetic shield members are arranged so as to be in contact with a lower side of the magnetic shield member. 6. A magnetic shield installed on a tank surface of a stationary induction appliance, wherein a magnetic shield member formed by laminating silicon steel strips bent in a U-shape in the width direction and a magnetic shield member arranged to fill a space surrounding the magnetic shield member. A magnetic shield for a static induction device, characterized by combining with a shield member. 7. A magnetic shield installed on a tank surface of a stationary induction device, after winding a silicon steel strip into a cylindrical shape,
A magnetic shield for a stationary induction machine, characterized in that it is elongated in an elliptical shape, its opposite long-side axis side is pressed, and its outer peripheral surface is made to face a stationary induction machine coil. 8. In a magnetic shield installed on a tank surface of a stationary induction device, after winding a silicon steel strip into a cylindrical shape,
A magnetic shield for a stationary induction device, wherein the magnetic shield is extended in an elliptical shape, the opposing long-side axis side is pressed and brought into contact, and the laminated surface is opposed to the stationary induction device coil. 9. In a magnetic shield installed on a tank surface of a stationary induction device, after winding a silicon steel strip into a cylindrical shape,
A magnetic shield for a stationary induction machine, characterized in that it is elongated in an elliptical shape, a plate-shaped magnetic shield member is arranged on the inner periphery thereof, and the outer peripheral surface thereof is opposed to the stationary induction coil. 10. A magnetic shield installed on a tank surface of a stationary induction electric machine, wherein a silicon steel strip is wound into a cylindrical shape and then elongated into an elliptical shape, and a flat magnetic shield member is disposed on an inner peripheral portion thereof. A magnetic shield for a static induction device, wherein the laminated surface is opposed to a static induction coil. 11. A magnetic shield installed on a stationary induction device clamp, wherein a silicon steel strip is wound into a cylindrical shape, formed into a desired size, fixed, and fixed on the clamp. Magnetic shield for induction machine. 12. A vertical magnetic shield in which a silicon steel strip is laminated on a tank surface of a stationary induction appliance so that its surface is vertical, wherein the width of the central part is wider than the width of both ends. And the magnetic shield of stationary induction equipment. 13. A magnetic induction device installed on a tank surface and a clamp of a static induction device, wherein a thick steel band is used as a silicon steel band used for a shield member. Magnetic shield. 14. A horizontal magnetic shield in which a silicon steel strip is laminated on a tank surface of a stationary induction device so that its surface is parallel to the tank surface. A magnetic shield for stationary induction equipment characterized by being installed in a stationary position. 15. A horizontal magnetic shield in which a silicon steel strip is laminated on a tank surface of a stationary induction appliance so that its surface is parallel, and a slit is formed in the steel strip surface along the longitudinal direction.
A magnetic shield for a static induction device, wherein the magnetic shield is formed in more than one place. 16. In a horizontal magnetic shield in which a silicon steel strip is laminated on a tank surface of a stationary induction device so that its surface is parallel to the tank, after winding the directional silicon steel strip in a cylindrical shape, one place is formed. A magnetic shield for a stationary induction device, characterized in that the magnetic shield is cut into a block shape, and furthermore, the reduced thickness portion is bent and deformed inward to form a flat surface in the longitudinal direction of the shield. 17. A vertical magnetic shield formed by laminating a silicon steel strip on a tank surface of a stationary induction appliance so that its surface is perpendicular to the tank surface, wherein a narrow pitch is formed on the tank-side lamination surface of the magnetic shield in a laminating direction. A magnetic shield for a stationary induction device characterized by being fixed. 18. A vertical magnetic shield in which a silicon steel strip is laminated on a tank surface of a stationary induction appliance so that its surface is vertical, and a plurality of silicon steel strips having a predetermined size are pressed by pressing a plate surface thereof. Are formed at a narrow pitch,
A stationary state characterized in that, at the time of laminating the silicon steel strips, the projections of the projections of the upper silicon steel strip are sequentially inserted into the recesses on the rear side of the projections of the lower silicon steel strip, and these are caulked and integrated. Magnetic shield for induction machine. 19. A binding tape such as a heat-shrink tape or a self-fusing tape at a narrow pitch in a vertical magnetic shield in which a silicon steel strip is laminated on a tank surface of a stationary induction appliance so that its surface is vertical. A magnetic shield for stationary induction appliances, characterized by being constrained and integrated with 20. In a vertical magnetic shield in which a silicon steel strip is laminated on a tank surface of a stationary induction appliance so that its surface is vertical, when the silicon steel strip is cut to a predetermined size, the magnetic shield is attached. Notches are formed at a narrow pitch on the surface side, and a steel plate bent in a U-shape is fitted into the notch by shrink fitting or press fitting or an L-shaped steel plate is installed in the notch, and then one side is A magnetic shield for a static induction device characterized by being bent, fitted and integrated. 21. The magnetic shield for a static induction device according to any one of claims 17 to 20, wherein a thick contact plate is arranged on both sides of the magnetic shield and integrated. Magnetic shield for stationary induction equipment. 22. A vertical magnetic shield formed by laminating a silicon steel strip on a tank surface of a stationary induction appliance so that the surface thereof is vertical, wherein the corrugated thin plate and the magnetic shield are juxtaposed, and the corrugated thin plate is provided. A magnetic shield for a stationary induction device, characterized in that the intervals between the peaks are formed at a narrow pitch. 23. The magnetic shield according to claim 22, wherein a vortex ring made of a thin plate is disposed in a space formed by the corrugated thin plate. 24. In a vertical magnetic shield in which a silicon steel strip is laminated on a tank surface of a stationary induction appliance so that its surface is vertical, a tank wall for mounting the magnetic shield is drawn into a concave shape, and the tank wall is formed. A method for mounting a magnetic shield, wherein a magnetic shield is press-fitted into the concave portion. 25. The magnetic shield mounting method according to claim 24, wherein a damping steel plate is interposed between the magnetic shield pressed into the concavely drawn tank wall and the tank wall. How to attach the shield. 26. A method of mounting a magnetic shield provided in a tank of a stationary induction device, wherein a holding block made of a permanent magnet is fixed to a mounting surface side of the magnetic shield, and a surface or a pair of the holding block which contacts the magnetic shield. A method for mounting a magnetic shield, wherein a vibration isolating material is arranged on a mounting surface side.