JPS60223105A - Manufacture of transformer for shielding noise - Google Patents

Abstract

PURPOSE:To obtain a transformer for shielding noises, in which two toroidal coils are magnetically shielded completely, at low cost by impregnating the whole surfaces of the coils with a fluid resin composition displaying high high- frequency permeability and curing the composition and fitting the coils to a ring magnetic core having high low-frequency permeability. CONSTITUTION:A primary coil 1 and a secondary coil 2 are dipped in a mixture in which ferrite group powder is mixed into a heating curing type epoxy group synthetic resin, a fluid is fast stuck onto the whose surfaces of coils 6, and the fluid is cured through heat treatment. A U-shaped magnetic core 3 having high low-frequency permeability is manufactured by laminating a large number of metal sheets obtained by rolling-working silicon steel plates displaying high permeability at 50Hz-60Hz commercial frequency, manufacturing metal sheets and punching-working the metal sheets to a U-shape. The primary coil 1 or the secondary coil 2 are fitted to the leg sections 5 of a pair of the U-shaped magnetic cores 3 manufactured in this manner, and mutually facing leg sections 5 are connected, thus obtaining a transformer for interrupting noises.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a method for manufacturing a noise-blocking transformer that blocks noise that invades electronic equipment, causes the equipment to malfunction, and in the worst case can even destroy the equipment. .

[Prior Art] Conventionally, noise generated by various causes spans a wide frequency band and has various energies, so it is almost impossible to uniformly remove all noise.

Moreover, with the progress of semiconductor technology, the processing speed of electronic devices has become faster and the signals handled have become smaller, so measures against noise have become particularly important in recent years.

Broadly speaking, these noises can be divided into two types: radiated noise that is emitted from the noise source into space and directly hits the electronic equipment, and noise that propagates from the noise source to the primary power supply and enters from the conductive path of the electronic equipment. It becomes. Among these, the most common method for dealing with radiation noise is to electrostatically and magnetically shield the entire electronic device from the side, and countermeasures are taken depending on the usage conditions of the electronic device. However, electronic equipment must always supply power to noise propagating through conductive lines, and only the necessary components are selected from the electrical energy propagating through the conductive lines, eliminating unnecessary noise. Blocking the noise component is complicated because the noise has a wide range of energy distribution in a wide frequency band as described above. As a device for removing noise propagating through the conductive path, a device for interrupting interference waves using a magnetic path disclosed in Japanese Patent Publication No. 56-35290 is effective.

However, since the above device has a complicated structure in which the circumferential surfaces of the primary and secondary coils of the transformer are wrapped in different magnetic materials, there are problems such as a large number of manufacturing steps and high manufacturing costs. It was something.

[Object of the invention] The present invention was made to solve the above problems, and
To provide a method for manufacturing a noise-blocking transformer that can reduce production costs and achieve highly reliable commercialization by manufacturing a transformer having the above-mentioned structure with good noise-blocking performance using a method most suitable for productivity. It is an object.

[Configuration of the Invention] The configuration of the present invention for achieving the above object is to form a layer of a fluid composition that is curable and exhibits high high frequency magnetic permeability at least after curing on the entire surface of each of the two annular coils, Noise caused by curing the fluid composition, then inserting the two coils into an annular magnetic core with high low-frequency magnetic permeability that is cut at one or more places, and joining the cut portions of the annular magnetic core together. The gist of this paper is a method of manufacturing a cut-off transformer.

The coil used in the present invention is manufactured by winding a highly conductive metal wire, such as a copper wire or the like, insulated lead wire a desired number of times along the circumferential surface of a cylinder or rectangular tube.

Furthermore, the fluid composition that exhibits high high-frequency magnetic permeability at least after curing refers to the following.

High frequency refers to the frequency band of noise that has an important effect on equipment, and usually ranges from several hundred KH2 to several Mt-1z.
This refers to the band of Therefore, the magnetic permeability is high in this frequency band,
The curable fluid composition is one in which magnetic powder particles, metal oxide magnetic powder particles, etc. are mixed with a two-component heat-curable or heat-curable synthetic resin such as epoxy or urethane.

These mixed compositions may be appropriately selected depending on the frequency of the noise to be blocked, and the mixing ratio thereof is selected in relation to the energy density of the noise. A layer of such a fluid composition is formed on the entire surface of the annular coil to provide magnetic shielding only for high frequencies. To form the layer, techniques such as dipping the coil in the composition, spraying, and coating are used, but the dipping method is preferred from the viewpoint of simplifying the construction and perfecting the magnetic shield.

Another method of using a composition with even higher fluidity is to prepare a box in advance to load the coil, and after loading the coil, pour the composition with higher fluidity into the box and soak the coil. method etc. may be adopted.

The flowable composition adhered to the coil by the various methods described above may be subjected to heat treatment depending on its f and the curability of the flowable composition. If so, it is hardened by adding a suitable hardening agent in advance before adhering to the coil, and is then tightly adhered and fixed to the coil.

Here, curing refers to making the hardness appropriate depending on the characteristics of the curable substance; for example, a urethane-based composition may be used to cure the material while maintaining a certain degree of elasticity. .

The magnetic core is made of a material with high low frequency magnetic permeability.

Here, the low frequency refers to the frequency component of the necessary electrical energy that propagates from the primary side to the secondary side of the FR transformer manufactured by the method of the present invention, and is the normal commercial frequency of 50H7~ Several tens including 60H7)-IZ~several hundred Hz
This is the band of Therefore, the material of the magnetic core used in ordinary power transformers, such as a material made by laminating a large number of silicon steel thin plates, can be used.

The shape of the magnetic core made of the above-mentioned VJ quality may be any shape as long as it becomes annular in the end, for example, an annular shape cut at one point, or an annular shape formed by connecting two members together. etc. Any of these may be used. An effective embodiment of the method of the present invention is preferably one in which two mouth-shaped magnetic cores are connected facing each other. In addition, to connect these two members, an adhesive exhibiting the same magnetic properties as the magnetic core, such as a hardening synthetic resin made by mixing silicon steel powder, or a bolt or nut, etc. may be used. It is sufficient to connect mechanically using J-. That is, as long as the low frequency magnetic path is not interrupted at the connecting portion of the two magnetic cores, any type of connection may be used as described above.

EMBODIMENT OF THE INVENTION Hereinafter, in order to explain more clearly the manufacturing method of the noise isolation transformer of this invention, one Example is demonstrated with reference to drawings.

[Example] FIG. 1 is an explanatory diagram of the configuration of a noise-blocking transformer manufactured in this example. In the figure, 1 indicates the primary coil, 2
3 represents a secondary coil, and 3 represents a square-shaped magnetic core with high low-frequency magnetic permeability.

A fitting hole 4 is formed in each of the primary coil 1 and the secondary coil 2, so that the leg portion 5 of the mouth-shaped magnetic core 3 can be fitted into the fitting hole 4.

The manufacturing method of each of the above components will be explained below.

FIG. 2 is a perspective view of the coil 6 that constitutes the primary coil 1 and secondary coil 2. FIG. The coil 6 is manufactured by winding a lead wire 8 so as to form a hollow part 7. The primary coil 1 and the secondary coil 2 are made by forming a layer with high high frequency magnetic permeability on the entire surface of the coil 6 to provide complete magnetic shielding against high frequencies. The magnetic shield layer is formed at least in a curable fluid composition that does not exhibit high high-frequency magnetic permeability after curing, that is, a heat-curable epoxy synthetic resin fluid in which ferrite powder is mixed. The coil 6 is immersed to bring the fluid into close contact with the entire surface of the coil 6, and then heated to harden the fluid.

The mouth-shaped magnetic core 3 with high low-frequency magnetic permeability has a commercial frequency of 50
1-1 It is obtained using a well-known technology that does not exhibit high magnetic permeability at z~60H2 and is manufactured by rolling a silicon steel plate into a thin plate, punching it into a mouth shape, and stacking a large number of them. . FIG. 1 shows a magnetic core 3 manufactured by the above technique, and 9 is a thin silicon steel plate. In addition, the leg portion 5 of each U-shaped magnetic core 3 is connected to the leg portion 5 of the opposite magnetic core 3.
The above-mentioned primary coil 1 or secondary coil 2 is integrated with
In order to fit the primary coil 1 and secondary coil 2, it is configured to be longer than at least 1/2 of the height of the fitting hole 4, and its circumference is slightly smaller than the diameter of the fitting hole 4. ing.

FIG. 3 shows a completed perspective view of the one-lance for noise isolation manufactured by the above method.

As is clear from the figure, there is only a magnetic circuit between the primary coil 1 and the secondary coil 2, and the magnetic circuit has -C for high frequency components, respectively on the primary and secondary sides. A closed circuit is formed, and no signal is propagated between the primary and secondary, and only low frequency components are propagated via the pair of U-shaped magnetic cores 3.

Therefore, no noise is propagated between devices connected to the primary side lead wire 8, such as electronic devices operated by the power source, and only the necessary electrical energy is propagated through the magnetic core 3 as magnetic energy. Ru.

As described above, according to this embodiment, magnetic shielding can be easily applied to the annularly wound coil 6, and the primary and secondary coils 1.2 thus made can be combined into a pair of coils. Since the transformer is manufactured by inserting it into a letter-shaped magnetic core, the process is simple and the production rate is greatly improved. Furthermore, since the number of parts is small, consisting of only two coils and a pair of U-shaped magnetic cores, the effect of simplifying parts management etc. is great.

[Effects of the Invention] As described in detail with reference to Examples, the method for manufacturing a noise-blocking transformer of the present invention includes coating a toroidal coil with a layer of a fluid composition that is curable and has high high-frequency magnetic permeability at least after curing. is formed on the entire surface to create a primary coil and a secondary coil,
The coil is fitted into an annular magnetic core with high low frequency magnetic permeability that is cut at one or more places, and then the annular magnetic core is bonded together.

Therefore, it is now possible to completely magnetically shield the primary and secondary coils using an extremely simple method, and the conventional noise-blocking transformers, which require a lot of time and effort to manufacture and are expensive, can be replaced. It can be manufactured at a low cost, and since the process is simple, it has an excellent effect of improving the reliability of the parts.

In addition, the composition to which magnetic shielding is applied can have various properties depending on the substance and amount thereof mixed in, so that various products can be manufactured depending on the usage mode. Furthermore, since the hardness of the composition after curing can be controlled, it is possible to make many variations of the product, such as making it elastic, especially for those used in places subject to a lot of mechanical shock. .

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the embodiment, FIG. 2 is a perspective view of the coil, and FIG. 3 is a completed perspective view. 1...Primary coil 2...Secondary coil 3...U-shaped magnetic core 6...Coil agent, patent attorney, Tsutomu Sadatsu and 1 other person

Claims (1)

[Claims] 1. Form a layer of a curable fluid composition that exhibits high high-frequency magnetic permeability at least after curing on the entire surface of each of the two annular coils, cure the fluid composition, and then cut at one or more locations. A method for manufacturing a noise-blocking transformer, in which the two coils are fitted into an annular magnetic core with high low-frequency magnetic permeability, and the cut portions of the annular magnetic core are joined together. 2. The method for manufacturing a noise-blocking i-lance according to claim 1, wherein the layer of the fluid composition is formed by immersing the coil in the fluid composition. 3. A method of manufacturing a sound isolation transformer according to claim 1 or 2, wherein the annular magnetic core comprises a pair of U-shaped magnetic cores.