JP2001267148A - Disturbance cut-off transformer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form the primary and secondary coils of a disturbance cut-off transformer by molding insulating resins by giving sufficiently high thermal and mechanical strengths to the coils and not deteriorating the disturbance cut-off ability of the coils. SOLUTION: The molded coils used in the noise-cutting transformer type distribance cut-off transformer having a coaxial different-center structure are formed in such a way that the multilayered multi-turn primary coil 1 which is entirely covered with a shielding body 4g composed of a short-circuit ring formed of an extremely fine net-like member, such as an aluminum expanded metal, etc., is integrally formed by molding an insulating resin 6a, and the multilayered multi-turn secondary coil 2 which is entirely covered with a shielding body 4h composed of a short-circuit ring formed an extremely fine net-like member, such as the aluminum expanded metal is formed by integrally molding another insulating resin 6b. In addition, the shielding bodies 4g and 4h are composed of short-circuit rings of thin conducting layers having thicknesses of 0.1-100 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transformer for interrupting a disturbance wave, such as a shield transformer or a noise cut transformer, which blocks a high-frequency disturbance wave (hereinafter also referred to as noise) transmitted through a power line or a signal line. The present invention relates to a disturbance wave blocking transformer in which a coil constituting the same is molded with an insulating resin. Here, the shield transformer is a transformer in which the primary coil and the secondary coil are separated by an insulator and an electrostatic shield is provided between the coils or an electrostatic shield is provided between the coils and on the outer periphery of the transformer. A noise cut transformer is a device that separates a primary coil and a secondary coil with an insulator and that an electromagnetic shielding plate is provided between the coils and on the outer periphery of the transformer, and that the primary coil and the secondary coil have a high frequency. A transformer having a structure in which the magnetic flux of the disturbance wave is arranged so as not to cross each other.

[0002]

2. Description of the Related Art In recent years, computer control facilities and systems have increased, and the information network has expanded from an in-house scale to an external scale, and even to a global scale. ing. For example, in an intelligent building or the like, many information devices are supplied with power from a common distribution line of commercial power.
For this reason, if external noise such as lightning surge, transmission line switching surge, or noise generated by other customers enters from the distribution line of commercial power, many information devices will be seriously damaged, Eventually it will lead to disaster. Therefore, it is necessary to prevent external noise from entering the building from the distribution line of commercial power.Specifically, shield transformers should be installed in transformers of power receiving and transforming facilities in buildings, and in power supply sections of important points in indoor distribution lines and important equipment. Moves to adopt noise cut transformers have become widespread.

[0003] In the event of a disaster such as the Great Hanshin-Awaji Earthquake, transformers in substation facilities in buildings have become a source of ignition or have spread fires. This was because the transformer used a large amount of mineral oil as an insulating agent to perform insulation and cooling.
Therefore, in order to avoid such a situation, it has been desired to replace the coil with a transformer insulated by using a solid flame-retardant insulator instead of mineral oil. However, since such transformers do not have the outer case of oil and iron for oil storage that conventional transformers using mineral oil as an insulating agent have, how to increase moisture proof and thermal and mechanical strength Is a problem. Therefore, as a solution, a coil made of a solid non-combustible insulator such as quartz powder mixed with a strong non-combustible insulating material such as quartz powder is mixed with a flame-retardant strong insulating resin such as epoxy. There is a strong demand from related industries to mold, or to add a tough cloth woven with glass fiber or glass fiber, etc. to these, and to integrally mold and use a mold transformer reinforced, insulated and molded. It has become.

Therefore, a shield transformer and a noise cut transformer are also formed by molding a coil with a solid flame-retardant insulating resin, for example, a synthetic insulating resin such as epoxy mixed with a solid non-flammable insulator such as quartz powder. It has been demanded to integrally mold the coil by adding a tough cloth such as glass fiber to these, or to integrally mold the shield transformer and the noise cut transformer as a whole. However, none of the resin-molded shield transformers and noise cut transformers have been developed for structural reasons.

For example, as shown in FIG. 15, a coil constituting a conventional noise cut transformer has an annular primary coil 1 formed by multiply winding an insulated copper wire 5 in multiple layers, and is wound all over the surface thereof. An insulating glass tape 9, an aluminum foil 8 as a shield wound around the entire surface of the insulating glass tape 9 without any gap,
And an insulating glass tape 10 wound around the entire surface of the aluminum foil 8. The aluminum foil 8 is a metal foil having no gaps or pores. After the winding of the insulating glass tape 9 is completed, an insulating operation including preliminary drying, varnish impregnation, varnish cutting, and drying and solidification is performed. If this varnish pickling operation is performed twice, it takes about 30 hours. After the winding of the insulating glass tape 10 is completed, the varnish-soaked-dry-solidification operation is performed once over about 14 hours. The secondary coil has the same structure as the primary coil and is manufactured by the same method.

[0006] The shield transformer is provided with a noise shielding shield between and around the coil in a larger area than the coil, and the noise cut transformer is ideally to completely cover the coil with the shield without any gap. In addition, the noise shielding shield is a metal foil or metal plate made of copper or aluminum having the best conductivity, and has no gaps or pores. For this reason, when a transformer having such a structure is molded with an insulating resin, the molded insulating resin is spontaneously peeled off on both surfaces of the metal plate of the noise shielding shield embedded therein, and the required mechanical strength is obtained. Not only can it not be maintained, but also defects such as partial discharge occur. In addition, if a transformer with a structure that is covered with a noise shielding shield without gaps is molded with insulating resin, the insulating resin cannot penetrate inside the noise shielding shield and the insulating resin does not reach the coil at all. I can't do that. Therefore, as for the shield transformer and the noise cut transformer, a mold transformer which has high moisture proof and high thermal and mechanical strength and can withstand a large earthquake has not been developed. The conventional shield transformer, abbreviated below, clearly illustrates this.

A conventional first shield transformer disclosed in Japanese Patent Application Laid-Open No. Hei 10-289828 discloses a method in which a low-voltage winding and a high-voltage winding wound on a bobbin are molded with an insulating resin, and a shield is formed on the surface of the molded exterior part. This is a coaxial eccentric structure transformer with a case attached.

A conventional surface mount type second shield transformer for a small electronic device disclosed in Japanese Patent Application Laid-Open No. 11-204352 discloses a primary coil and a secondary coil wound around a square-shaped core. This is a transformer having an off-axis / off-center structure, which is formed by molding with resin and then electromagnetically shielding the surface of the sealing insulating resin with metal plating.

In the third conventional shield transformer disclosed in Japanese Patent Application Laid-Open No. 6-45162, a coil is insulated with an insulating material, and then the inner and outer peripheral surfaces thereof are subjected to an electrostatic shield with a conductive material. The outside is molded with a synthetic insulating resin mixed with a powder of a magnetic material with good high-frequency characteristics, and these coils are separately and independently mounted on the core, and a high-frequency magnetic shield is interposed between each coil. It is a configured coaxial eccentric structure transformer.

A fourth conventional shield transformer disclosed in Japanese Patent Laid-Open No. 6-318523 has a low-voltage side winding disposed inside and a high-voltage side winding formed of a disk winding disposed outside, and at least a high-voltage side winding is formed. In a molded transformer in which the side winding is formed by molding with an insulating resin, the outer peripheral portion of the disk winding constituting the high-voltage side winding covers a substantially cylindrical upper half of the disk winding in the axial direction. A first shield of the conductor is buried in the insulating resin, and a second shield, which is conical and extends substantially in the entire axial direction of the disc winding, is buried in the insulating resin on the inner peripheral surface of the disc winding. The first and second shields are connected to both ends of a high-voltage side winding, respectively, to form a transformer having a coaxial concentric structure.

The above-mentioned first to third shield transformers are not transformers having a structure in which a shield is buried in an insulating resin and are integrally molded. Therefore, none of these transformers can be said to be complete mold transformers. In the above-mentioned conventional fourth shield transformer, a cylindrical first shield is disposed on the outer periphery of the high-voltage side winding, and a conical second shield is disposed on the inner periphery thereof. The cylindrical first shield and the conical second shield are embedded in an insulating resin. However, since the insulating resin is not connected between the inner peripheral surface and the outer peripheral surface of the shield, the insulating resin peels off from the surface of the shield, resulting in a coil that is extremely weak against external force. Therefore, none of the above four conventional shield transformers has sufficient strength to withstand a disaster such as a large earthquake, either thermally or mechanically.

[0012] As for a noise cut transformer, one obtained by molding the same with an insulating resin has not been developed. That is, Patent No. 2645256 previously obtained by the inventor of the present application
The noise cut transformer disclosed in Japanese Patent Application Publication No.
This is a short-circuit ring type disturbance wave blocking transformer characterized in that a shield made of a conductive thin-layer short-circuit ring having no hole and no gap having a thickness of 0 μm is provided. What has not been developed.

Further, the inventor of the present application has published a journal of the Institute of Electrical and Electronics Engineers (IEEE TRANSACTION ON ELECTROMAGN).
ETIC COMPATIBILITY Vol.41, No.3, August 1999) announced the noise cut transformer type
A short-circuit ring of a conductive thin film having a thickness of about 7 μm or less is provided near each of the primary coil and the secondary coil, specifically, between these two coils. There is a high-frequency band exceeding several MHz, and particularly a high-frequency band exceeding 10 MHz, which maintains a high noise attenuation rate, and each of the irregular sawtooth waves in which various peaks and valleys of the characteristic curve of the noise attenuation rate are continuous. It has the feature of sufficiently suppressing the amplitude. The short-circuit ring of the conductive thin film is a substantially ring-shaped aluminum foil having no holes or gaps as shown in FIG. As for this noise cut transformer type disturbance wave cut-off transformer, one with an insulating resin mold has not been developed.

[0014]

SUMMARY OF THE INVENTION An object of the present invention is to provide a shield transformer type disturbance wave blocking transformer or a noise cut transformer type disturbance wave blocking transformer.
An object of the present invention is to provide an insulating resin mold with sufficient thermal strength and mechanical strength and without reducing the required performance of the shield and the short-circuit ring to such an extent that they are not practically hindered.

[0015]

According to a first aspect of the present invention, there is provided a shield transformer type disturbance wave blocking transformer according to the first aspect, comprising: a primary coil; a secondary coil; and a gap between the primary coil and the secondary coil and an outer periphery thereof. And a core that forms a magnetic path between the primary coil and the secondary coil, and the shield is formed of an extra fine mesh member, and the primary coil The secondary coil and the shield were molded with an insulating resin.

According to a second aspect of the present invention, there is provided a noise cut transformer type disturbance wave blocking transformer according to the second aspect, wherein a core forming a primary coil, a secondary coil, and a magnetic path between the primary coil and the secondary coil. And a shielding member formed of a conductive member having an extremely fine mesh shape is disposed on at least a peripheral surface of the primary coil, and the primary coil and the secondary coil are molded with an insulating resin together with the shielding member. did.

According to a third aspect of the present invention, there is provided a noise cut transformer type disturbance wave blocking transformer according to the third aspect, wherein a core forming a primary coil, a secondary coil, and a magnetic path between the primary coil and the secondary coil. And a skin depth formed by a skin effect of an induced current in a high-frequency region of an obstacle wave in which a thickness of a conductive portion is formed at least on a peripheral surface of the primary coil and a thickness of a conductive portion of the member is to be suppressed. A shield comprising a short-circuit ring of a conductive thin film substantially equal to or less than the above was provided, and the primary coil and the secondary coil were molded with an insulating resin together with the shield.

A noise-cut transformer type disturbance wave blocking transformer according to claim 4 which solves the above-mentioned problem is provided in the vicinity of a primary coil, a secondary coil, and one or both of the primary coil and the secondary coil. A short-circuiting ring of a conductive thin film formed of an extra-fine mesh member provided, and a core forming a magnetic path between the primary coil and the secondary coil, and a short-circuit of the conductive thin film In the ring, the thickness of the conductive portion of the member is substantially equal to or less than the skin depth due to the skin effect of the induced current in the high frequency region of the disturbance wave for which resonance is to be suppressed, and further, the primary coil and the secondary coil Was molded with an insulating resin together with the short-circuit ring of the conductive thin film.

Further, in the disturbance wave blocking transformer according to any one of claims 1, 2, 3 and 4, the ultrafine net-like member has a mesh tape formed by knitting a thin metal wire into a tube.
Conductive fiber woven with good conductive materials such as nylon and silver,
Conductive fibers with woven fabric coated with a good conductive material such as copper or nickel, conductive fibers with non-woven fabric coated with a good conductive material such as copper or nickel, expanded metal such as copper, copper alloy, or aluminum, or thin metal wires A bag-knitted mesh tape was used.

[0020]

FIG. 1 is a sectional view of a molded coil according to a first embodiment used in a shield transformer type disturbance wave blocking transformer having a coaxial concentric structure. The molded coil shown in FIG. 1 includes a primary coil 1, a secondary coil 2, and a shielding member 7 formed of a micro net member disposed between the primary coil 1 and the secondary coil 2, and an insulating resin 6. And is integrally molded. The primary coil 1 is a ring-shaped coil configured by winding an insulated copper wire 5. Secondary coil 2 arranged in a coaxial concentric structure with primary coil 1
Is a ring-shaped coil having a diameter smaller than that of the primary coil 1 and similarly formed by winding an insulated copper wire 5. The insulated copper wire 5 is a general one in which an insulating coating such as enamel is applied to the surface of the copper wire.

FIG. 2 is a sectional view of a molded coil according to a second embodiment used for a shield transformer type disturbance wave blocking transformer having a coaxial concentric structure. The molded coil shown in FIG. 2 is configured by further applying a second shield to the molded coil of the first embodiment, and includes a primary coil 1, a secondary coil 2, a primary coil 1, and a secondary coil. 2 and a shield 7b formed of an extra fine mesh member disposed on the outer periphery of the primary coil, and a shield 7a formed of an extra fine net member disposed between the first and second coils. It is composed.

Shields 7, 7a and 7b employed in the shield transformer type disturbance wave blocking transformer shown in FIGS. 1 and 2.
Is a mesh tape made of thin metal wires in a tubular knit, conductive fibers woven with good conductive materials such as nylon and silver, conductive fibers coated with a good conductive material such as copper or nickel, and nonwoven fabric made of copper or Conductive fiber coated with a good conductive material such as nickel,
Mesh tape made of thin metal wire made into a bag, or FIG.
It is formed of an extra-fine net-like member such as an expanded metal such as copper, copper alloy, or aluminum having the shape shown in FIG.

FIG. 3 is a sectional view of a molded coil according to a first embodiment used in a noise cut transformer type disturbance wave blocking transformer having a coaxial eccentric structure. The molded coil shown in FIG. 3 is a short-circuit ring and shield formed by a primary coil 1 having a multi-layered number of turns, a secondary coil 2 having a multi-layered number of turns, and an extra fine mesh member interposed therebetween. 4 and insulating resin 6
And is integrally molded.

FIG. 4 is a cross-sectional view of a molded coil according to a second embodiment used in a noise cut transformer type disturbance wave blocking transformer having a coaxial eccentric structure. The molded coil shown in FIG. 4 has a short-circuit ring 4a formed on its upper side with a microfine net-like member.
Is disposed in close proximity to the primary coil 1 of the multi-layer, multi-turn winding,
On the lower side, a short-circuit ring 4b formed of an extra fine net-like member is formed by integrally molding a secondary coil 2 having a multi-layered number of turns and disposed in close proximity with an insulating resin 6.

FIG. 5 is a sectional view of a molded coil according to a third embodiment used in a noise cut transformer type disturbance wave blocking transformer having a coaxial eccentric structure. That is, in the molded coil shown in FIG. 5, a cylindrical short-circuit ring 4c formed of a fine mesh member is formed on the outer peripheral surface thereof, and a cylindrical short-circuit ring 4d formed of a fine mesh member is formed on the inner circumferential surface thereof. The arranged primary coil 1 having a number of turns of multiple windings, a cylindrical short-circuit ring 4e formed on the outer peripheral surface thereof with a fine mesh member, and a cylindrical short-circuit ring 4f formed on the inner peripheral surface thereof with a fine mesh member are provided. It is formed by molding integrally with the secondary coil 2 having a multi-layer, multi-turn number, which is arranged in close proximity to each other. Each of the cylindrical short-circuit rings 4c to 4f is a short-circuit ring of a conductive thin layer having a thickness of 0.1 to 100 μm.

FIG. 6 is a sectional view of a molded coil according to a fourth embodiment used in a noise cut transformer type disturbance wave blocking transformer having a coaxial eccentric structure. That is, the molded coil shown in FIG. 6 has a multi-layer primary winding 1 in which a shielding body 4g composed of a short-circuit ring formed of an extra fine mesh member is disposed on the entire peripheral surface, and a short-circuit formed by an extra fine mesh member. A secondary coil 2 having a multi-layered multi-turn structure in which a shield 4h formed of a ring is disposed on the entire peripheral surface.
And are integrally molded. Each of the shields 4g and 4h is a shield composed of a short-circuit ring of a conductive thin layer having a thickness of 0.1 to 100 μm.

FIG. 7 is a sectional view of a molded coil according to a fifth embodiment used in a noise cut transformer type disturbance wave blocking transformer having a coaxial eccentric structure. In other words, the molded coil shown in FIG. 7 is obtained by molding the primary coil 1 having a multi-layered multi-turn structure in which the short-circuiting / shielding member 4 formed of a very fine net-like member is disposed close to the lower surface thereof with the insulating resin 6. The secondary coil 2 having a multi-layered number of turns is also molded with an insulating resin 6.

FIG. 8 is a sectional view of a molded coil according to a sixth embodiment used in a noise cut transformer type disturbance wave blocking transformer having a coaxial eccentric structure. The molded coil shown in FIG. 8 has a short-circuit ring 4a formed on its upper side with a microfine mesh member.
Are molded integrally with the insulating resin 6 and the short-circuit ring 4b formed of a micro-mesh-like member is closely disposed below the primary coil 1 having a multi-layered multi-turn structure. The secondary coil 2 having the number of turns is integrally molded with the insulating resin 6.

FIG. 9 is a cross-sectional view of a molded coil according to a seventh embodiment used in a noise cut transformer type disturbance wave blocking transformer having a coaxial eccentric structure. That is, in the molded coil shown in FIG. 9, a cylindrical short-circuit ring 4c formed of an extra fine mesh member is formed on the outer peripheral surface thereof, and a cylindrical short circuit ring 4d formed of an extra fine mesh member is formed on the inner peripheral surface thereof. The arranged primary coil 1 having a multi-turn winding is integrally molded with an insulating resin 6, and a cylindrical short-circuit ring 4 e formed of an extra fine mesh member is formed on the outer peripheral surface thereof, and an extra fine mesh member is formed on the inner peripheral surface thereof. The cylindrical short-circuit ring 4f is formed by integrally molding the secondary coil 2 having a multi-layered number of turns arranged in close proximity to each other. Each of the cylindrical short-circuit rings 4c to 4f is a short-circuit ring of a conductive thin layer having a thickness of 0.1 to 100 μm.

FIG. 10 is a sectional view of a molded coil according to an eighth embodiment used in a noise cut transformer type disturbance wave blocking transformer having a coaxial eccentric structure. The molded coil shown in FIG. 10 has a multi-layer, multi-turn primary coil 1 in which a shielding body 4 g formed of a short-circuit ring formed of an extra fine mesh member is provided on the entire peripheral surface, and is integrally molded with an insulating resin 6, and The secondary coil 2 has a multi-layer, multi-turn structure in which a shield 4h formed of a short-circuit ring formed of a net-like member is disposed on the entire peripheral surface, and is integrally molded with an insulating resin 6. And 4g of shield
And 4h are shields formed of short-circuit rings of conductive thin layers each having a thickness of 0.1 to 100 μm.

The shields 4 (4a to 4a) employed in the noise cut transformer type disturbance wave blocking transformer shown in FIGS.
4h. same as below. ) Is a mesh tape made of thin metal wire formed into a tubular knit, a conductive fiber woven with a good conductive material such as nylon and silver, a conductive fiber coated with a woven fabric with a good conductive material such as copper or nickel, Conductive fibers obtained by coating a non-woven fabric with a good conductive material such as copper or nickel, mesh tape formed by sewing a thin metal wire, or extra-fine mesh such as an expanded metal such as copper, copper alloy, or aluminum having a shape as shown in FIG. A shield formed of a member, wherein a thickness of the conductive portion is substantially equal to or less than a skin depth due to a skin effect of an induced current in a high-frequency region of an obstacle wave whose resonance is to be suppressed.

In particular, the short-circuit ring employed in the noise cut transformer type disturbance wave cut-off transformer shown in FIGS. 3, 4, 7, and 8 is substantially ring-shaped as shown in FIG. The thickness of the conductive portion is substantially equal to or less than the skin depth due to the skin effect of the induced current in the high frequency region of the disturbance wave whose resonance is to be suppressed.

The basic configuration is the same as that of the noise cut transformer type disturbance wave blocking transformer coil shown in FIG. 5, FIG. 6, FIG. 9 or FIG. , A secondary coil, and a core that forms a magnetic path between the primary coil and the secondary coil, a shield formed of a conductive member having a fine net shape at least on the peripheral surface of the primary coil. The noise cut transformer type disturbance wave blocking transformer according to the present invention is further provided, wherein the primary coil and the secondary coil are molded with an insulating resin together with the shield. Wave breaking transformer. In this case, the shield does not function as a short-circuit ring, but simply functions as a shield.However, a mesh tape made of thin metal wires in a tubular braid, or a conductive fiber woven with a good conductive material such as nylon and silver , Conductive fibers coated with a good conductive material such as copper or nickel, conductive fibers coated with a non-woven fabric with a good conductive material such as copper or nickel, mesh tape formed by thin metal wire into a bag, or FIG. It is a shield formed of an extra-fine mesh member such as an expanded metal such as copper, copper alloy, or aluminum having the shape shown.

Here, the shielding effect of the shielding member formed of the above-mentioned ultrafine net-shaped conductive member will be described with specific numerical values with reference to FIGS. 16, 17 and 18. FIG.

FIG. 16 is a graph showing calculated values of the shielding effect of two copper plates having a thickness of 100 μm and a thickness of 10 μm, each of which is a copper plate having no gap at all, and the horizontal axis of the logarithmic scale indicates frequency. The vertical axis of the equally-spaced scale is 1 m from the electric field radiation source.
m represents the attenuation at a very close position.

That is, in FIG. 16, the absorption loss of an electric field by a copper plate having a thickness of 100 μm, which is a copper plate having no gap at all, is 41.6 dB at 10 MHz and 1 at 100 MHz.
The lower the frequency is 31.6 dB and 416.2 dB at 1 GHz, the lower the loss. However, the return loss is 171.7 dB at 100 MHz and 100 MHz regardless of the thickness of the copper plate.
The lower the frequency is 141.7 dB at z and 111.7 dB at 1 GHz, the greater the loss. The sum of the absorption loss and the reflection loss is the total loss, which is the attenuation of the electric field of the copper plate. When this is expressed as an attenuation rate, the sign becomes negative, and the attenuation rate of a copper plate having a thickness of 100 μm is −2 at 10 MHz.
13.3dB, -273.3dB at 100MHz, 1G
It becomes -527.9 dB in Hz. As can be seen from the characteristic curve of the total loss of a copper plate having a thickness of 100 μm, even at the point where the attenuation rate is the lowest, the value does not fall below −200 dB (1/100 billion in magnification).

In FIG. 16, the absorption loss of a copper plate having no gap and having a thickness of 10 μm is 10 μm.
4.16dB at MHz, 13.16d at 100MHz
B, 41.62 dB at 1 GHz, but the return loss is 1
171.7 dB at 0 MHz, 141.7 at 100 MHz
dB, 11.7 dB at 1 GHz, and thus a thickness of 1
The attenuation factor of the 0 μm copper plate is −175.9 at 10 MHz.
dB, 154.9 dB at 100 MHz, 1 GHz-1
53.3 dB. As can be seen from the characteristic curve of the total loss of a copper plate having a thickness of 10 μm, even a thickness of 10 μm is −150 d.
It does not fall below B (magnification: 1 / 1.65 million).

In short, even if the copper plate is a thin copper plate of 10 μm and has no gap at all, one copper plate from the radiation source of the electric field is required.
FIG. 16 shows that the electric field can be attenuated by -150 dB or more even at a position very close to mm.

On the other hand, there are many gaps,
In the case of a very fine mesh conductive member having non-uniform electrical conductivity, this cannot be included in the calculation. Therefore, as a result of actual measurement by the Advantest method, the shielding effect of five typical mesh and woven samples is shown in FIG. 18 and FIG.

That is, the attenuation rate of an aluminum expanded net having 97 holes per square centimeter and having a thickness of 50 μm is, as shown by the curve (a) in FIG.
-38 dB to -5 in the high frequency band from 0 MHz to 1 GHz
It was 4 dB.

The attenuation rate of the copper expanded net having 178 holes per square centimeter and having a thickness of 100 μm, as shown by the curve in FIG.
-48 dB to -7 in the high frequency band from 0 MHz to 1 GHz
It was 1 dB.

Further, the open mesh 22 has a thickness of 80 to
As shown by the curve (c) in FIG. 18, the attenuation rate of the 90-μm silver yarn woven fabric was −41 dB to −61 dB in the high frequency band from 100 MHz to 1 GHz.

Further, the attenuation rate of the copper / tin-plated wire mesh tape of the 540-μm-thick bag net having 35 holes per square centimeter, as shown by the curve in FIG. In the high frequency band of 1 GHz, it was -44 dB to -62 dB.

Furthermore, copper having a thickness of 100 to 200 μm
The attenuation rate of the nickel-plated woven fabric was -52 dB to -85 dB in a high frequency band from 100 MHz to 1 GHz as shown by the curve (E) in FIG.

In short, from a frequency of 100 MHz to 1 GH
In the high frequency band of z, even at a position as close as 1 mm from the radiation source of the electric field, the shield formed by the typical ultrafine reticulated conductive member is not as large as a copper plate with no gap at all. It has been found that although the attenuation rate of the digits is low, an attenuation rate of −38 dB or more, which is sufficient as a practical shielding effect, is achieved. It is needless to say that the attenuation rate can be improved by providing multiple layers with a porous or fibrous insulating layer interposed therebetween, if necessary.

Next, a description will be given of a method of manufacturing a molded coil constituting the disturbance wave blocking transformer according to the present invention. The molded coil according to the present invention is, for example, in a preparation step of setting the primary coil 1 and the secondary coil 2 together with the shield in the mold, and in the mold in which the primary coil 1, the secondary coil 2 and the shield are set. It is manufactured by a casting method including a synthetic insulating resin liquid injecting step of injecting a synthetic insulating resin liquid and removing the bubbles by vacuuming, and a curing step. The curing step includes a heat curing step performed as necessary. In the present invention, since the shield is formed of the above-described ultrafine net-like member, the synthetic insulating resin passes through the pores of the shield, reaches the inner peripheral surface from the outer peripheral surface, and further penetrates between the coil layers.
The whole is solidified integrally and does not peel off from the shield. Accordingly, a molded coil having excellent thermal strength and mechanical strength in one molding operation has been provided. In addition, in the synthetic insulating resin liquid injection step, not only the synthetic insulating resin liquid but also a synthetic non-flammable insulating material such as quartz powder mixed with the synthetic insulating resin liquid or a glass fiber or the like is added as necessary. Is also used. By doing so, the mechanical strength can be further increased. In addition, the manufacturing method of the molded coil for the disturbance wave blocking transformer according to the present invention is not limited to the casting method described above.

Further, as can be easily understood from the above-described method for manufacturing a molded coil, the disturbance wave blocking transformer according to the present invention having a molded coil is different from the conventional method for manufacturing a coil described with reference to FIG. For example, it is not necessary to perform two operations of winding the insulating glass tape and three operations of dipping in varnish and drying and solidifying, so that the manufacturing time of the coil can be significantly reduced.

Further, as can be easily understood from the above-described method for manufacturing a molded coil, a rectangular cross section is not used as the ring coil having the rectangular cross section illustrated in FIGS. Square coil, circular cross-section ring-shaped coil, circular cross-section rectangular coil, etc., for a disturbance wave blocking transformer according to the present invention, which is excellent in thermal strength and mechanical strength in a single molding operation Needless to say, a molded coil can be provided, and its manufacturing time can be greatly reduced. In short, the cross-sectional shape and planar shape of the coil
The shape of the short-circuit ring corresponding to the planar shape of the coil has no influence on the manufacture of the molded coil for the fault wave blocking transformer according to the present invention.

A core forming a magnetic path between the primary coil 1 and the secondary coil 2 has a thickness of 0.5 mm as shown in FIG.
E of specified dimensions manufactured by stamping non-oriented silicon steel sheet
This is a general one formed by laminating a mold core piece and an I-shaped core piece to a predetermined thickness. By applying this core to the molded coil shown in FIGS. 3 to 10, a sufficient thermal strength and a high mechanical strength are required, and a shielding effect is practically required as compared with the conventional untransformed shield transformer. There is provided a noise cut transformer type disturbance wave blocking transformer which is a molded transformer having a coaxial eccentric structure which does not decrease until the effect is lost. The same strength can be obtained by using a core obtained by cutting a silicon steel sheet into strips and combining and laminating them, or by using a wound iron core made of a directional silicon steel strip. It is. The same applies to any shape for three-phase, single-phase, and other applications.

Further, by applying this core to the molded coil shown in FIG. 1 or FIG. 2, the shielding effect is higher than that of the conventional untransformed shield transformer with high thermal strength and mechanical strength. Provided is a shield transformer type disturbance wave blocking transformer which is a molded transformer having a coaxial concentric structure which does not decrease until the effect required for practical use is lost.

As described above, as the embodiments of the present invention, a molded transformer having a coaxial concentric structure is used for the shield transformer type disturbance wave blocking transformer, and a molded transformer having a coaxial eccentric structure is used for the noise cut transformer type disturbance wave breaking transformer. Detailed explanation. However, the present invention is not limited to these embodiments. That is,
For the noise cut transformer type disturbance wave blocking transformer,
By appropriately selecting the core, a mold transformer having a coaxial concentric structure, an off-axis eccentric structure, or an off-axis eccentric twist structure can be configured according to the present invention. The core can of course be used in a wound core.

[0052]

Since the shield transformer type disturbance wave blocking transformer according to the present invention uses a shield formed of an extra fine mesh member, the shield is completely embedded in the resin mold applied to the coil. In addition, since the resin mold is rigidly connected through the myriad of fine holes or fine gaps of the shield, a shield transformer type disturbance wave interrupting transformer which is a mold transformer having sufficient thermal strength and mechanical strength is provided. Was. Moreover, the shield formed by the ultrafine net-like member, compared to a plate-shaped or foil-shaped shield plate having no holes or gaps,
Since the shielding effect does not decrease until the effect required for practical use of noise cutoff is lost, the performance does not matter at all in practical use.

Further, since the noise cut transformer type disturbance wave blocking transformer according to the present invention uses a shield formed of a fine net-like member or a shield formed of a short-circuit ring, the noise cut transformer-type transformer is provided in a resin mold applied to the coil. The shield is completely buried,
In addition, since the resin mold is rigidly connected through the myriad of fine holes or minute gaps of the shield, a noise cut transformer type disturbance wave interrupting transformer, which is a mold transformer having sufficient thermal strength and mechanical strength, is provided. Was. Moreover, the short-circuit ring formed by the ultrafine net-like member has a high-frequency cutoff effect lower than the practically necessary effect of noise cutoff, as compared with a plate-shaped or foil-shaped short-circuit ring having no holes or gaps. No performance is a problem in practice.

Further, in the disturbance wave blocking transformer according to the present invention, the time required for manufacturing the molded coil is greatly reduced as compared with the conventional coil manufacturing, so that the manufacturing cost is reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a molded coil according to a first embodiment used in a shield transformer type disturbance wave blocking transformer. However, the thickness of the shield is exaggerated, and the same applies to the following drawings.

FIG. 2 is a cross-sectional view of a molded coil according to a second embodiment used in a shield transformer type disturbance wave blocking transformer.

FIG. 3 is a cross-sectional view of the molded coil of the first embodiment used in the noise cut transformer type disturbance wave blocking transformer.

FIG. 4 is a cross-sectional view of a molded coil according to a second embodiment used in a noise cut transformer type disturbance wave blocking transformer.

FIG. 5 is a cross-sectional view of a molded coil according to a third embodiment used in a noise cut transformer type disturbance wave blocking transformer.

FIG. 6 is a cross-sectional view of a molded coil according to a fourth embodiment used in a noise cut transformer type disturbance wave blocking transformer.

FIG. 7 is a cross-sectional view of a molded coil according to a fifth embodiment used in a noise cut transformer type disturbance wave blocking transformer.

FIG. 8 is a cross-sectional view of a molded coil according to a sixth embodiment used in a noise cut transformer type disturbance wave blocking transformer.

FIG. 9 is a cross-sectional view of a molded coil according to a seventh embodiment used in a noise cut transformer type disturbance wave blocking transformer.

FIG. 10 is a sectional view of a molded coil according to an eighth embodiment used in a noise cut transformer type disturbance wave blocking transformer.

FIG. 11 is a perspective view of an example of a core.

FIG. 12 is a plan view of an example of a ring-shaped short-circuit ring of a conductive thin film formed of a micro net-like member.

FIG. 13 is a perspective view of an expanded metal used as an extra fine mesh member.

FIG. 14 is a plan view of an example of a conventional ring-shaped short-circuit ring of a conductive thin film having no gaps and no pores.

FIG. 15 is a cross-sectional view of a conventional coil used in a noise cut transformer type disturbance wave blocking transformer.

FIG. 16 is an attenuation characteristic diagram showing an electric field shielding effect by a metal plate.

FIG. 17 is an attenuation characteristic diagram showing a shielding effect of an expanded network.

FIG. 18 is an attenuation characteristic diagram showing a shielding effect of woven fabrics.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Primary coil 2 Secondary coil 3 Core 4, 4a-4h Shield 5 Insulated copper wire 6, 6a, 6b Insulating resin mold 7, 7a, 7b Shield 8 Shield 9, 10 Insulator

Claims (5)

[Claims] 1. A primary coil, a secondary coil, a shield disposed between and between the primary coil and the secondary coil, and a magnetic path between the primary coil and the secondary coil. Wherein the shield is formed of an extra fine mesh member and is molded with an insulating resin together with the primary coil, the secondary coil, and the shield. Transformer type disturbance wave cut-off transformer. 2. A disturbance wave blocking transformer comprising a primary coil, a secondary coil, and a core forming a magnetic path between the primary coil and the secondary coil, wherein at least a peripheral surface of the primary coil is provided. , A shielding member formed of a fine net-shaped conductive member is provided, and the primary coil and the secondary coil are molded with an insulating resin together with the shielding member. Type disturbance wave interruption transformer. 3. An obstacle wave cut-off transformer comprising a primary coil, a secondary coil, and a core forming a magnetic path between the primary coil and the secondary coil, wherein at least on a peripheral surface of the primary coil A short-circuit ring of a conductive thin film formed of a very fine net-like member and having a thickness of a conductive portion of the member substantially equal to or less than a skin depth due to a skin effect of an induced current in a high frequency region of an obstacle wave in which resonance is to be suppressed. Wherein the primary coil and the secondary coil are molded with an insulating resin together with the shield. 4. A short-circuit ring of a conductive thin film formed of a primary coil, a secondary coil, and an extra fine mesh member disposed close to one or both of the primary coil and the secondary coil. In a disturbance wave cut-off transformer comprising a core forming a magnetic path between the primary coil and the secondary coil, the short-circuit ring of the conductive thin film has a thickness where a thickness of a conductive portion of the member is desired to suppress resonance. In the high frequency region of the wave, the skin depth is substantially equal to or less than the skin depth due to the skin effect of the induced current, and the primary coil and the secondary coil are molded with an insulating resin together with the short-circuit ring of the conductive thin film. A noise-cut transformer-type obstacle wave cut-off transformer characterized by being performed. 5. The ultra-fine net-like member is formed by covering a metal tape with a tubular braided mesh tape, a conductive fiber obtained by weaving a good conductive material such as nylon and silver, and a woven fabric with a good conductive material such as copper and nickel. Conductive fiber, non-woven fabric coated with a good conductive material such as copper or nickel, conductive fiber, expanded metal such as copper, copper alloy, aluminum, etc. The fault wave blocking transformer according to claim 1, 2, 3, or 4, wherein: