JPH0636566Y2 - Disturbance prevention transformer - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disturbance wave prevention type transformer for preventing noise in a high frequency range superimposed on a commercial power source from entering electric equipment.

[0002]

2. Description of the Related Art In general, in information equipment, medical equipment, audio equipment, control equipment, etc., in order to prevent the circuit of the equipment from being broken or the equipment from malfunctioning due to noise transmitted through a commercial power line. In addition, a disturbance wave prevention type transformer is interposed between the device and the commercial power source to prevent noise from entering the device.

Conventionally, as a transformer of this type, an electrostatic shielded primary winding and secondary winding are wound around different locations of an iron core formed of a silicon steel plate having a low high-frequency effective magnetic permeability. There is known a structure in which a transformer main body in which a non-ferrous metal good conductive shield plate is arranged between the primary winding and the secondary winding is housed in a conductive outer box. According to this structure, the main body of the transformer is covered by the outer box, and the primary winding and the secondary winding in the outer box are partitioned by the shielding plate, so that the primary winding and the secondary winding are Since the capacitance between the secondary windings can be greatly reduced, it is possible to obtain a disturbance wave prevention type transformer capable of transforming only a commercial frequency component or a frequency component close to it.

However, in the case of the above-mentioned conventional transformer, the peripheral edge of the shield plate is not in close contact with the wall surface of the outer box. Also, regarding the shield of the winding wire, it was difficult to reliably shield the lead wire portion over the entire area, so that it was unavoidable that an incomplete portion of the electrostatic shield occurred. Therefore, when the transformer is used, the noise radiated from the lead wire of one winding repeatedly enters the other winding side through the gap between the peripheral edge of the shielding plate and the inner wall surface of the outer casing while being repeatedly reflected on the outer casing wall. Then, it sometimes invaded the lead wire of the winding. Moreover, due to the gap existing between the periphery of the shield plate and the inner wall surface of the outer box, stray capacitance existed between the primary winding and the secondary winding. Therefore, depending on the type of noise, it was not possible to sufficiently prevent the noise from entering.

In order to solve the above-mentioned drawbacks, therefore, the shield plate is formed to a size reaching the inner wall surface of the outer box, and the periphery of the shield plate is attached to the inner wall surface of the grounded outer box with an adhesive tape,
A transformer has been devised, which is fixed by an adhesive or the like, and the lead wire of each winding is separately led out from the wall surface of the outer box. By doing this, the primary winding and 2
Since it is possible to partition the space between the next windings by a shielding plate,
It is possible to prevent noise radiated from the lead wire of one winding from entering the other winding side and to
The stray capacitance between the secondary windings can be minimized.

[0006]

[Problems to be solved by the invention] However, in the case of such a transformer, in order to fix the peripheral edge of the shield plate to the inner wall surface of the outer box, after the transformer body is housed in the outer box, Since it must be done by inserting a finger into the narrow space between the iron core or the winding and the inner wall surface of the outer box from the opening of the, workability is poor, so fixing work takes a lot of time and transformer It had the drawback of being expensive.

In addition, since the electrical connection between the shield plate and the outer box is not sufficient because it is only fixed with an adhesive tape or the like, the electric resistance of the fixed portion becomes large, and the shield plate is grounded more than the ground potential of the outer box. However, it was unavoidable that the blocking effect of the shielding plate against noise was lowered due to the increase in the potential of the. Moreover, with such a fixing method, it is difficult to securely adhere the peripheral edge of the shield plate to the wall surface of the outer box, and it is easy for a minute gap to occur in a part of the area. During the operation, new minute gaps are likely to occur at the initial contact points, and the initial minute gaps are likely to gradually increase. Therefore, the stray capacitance existing between the primary and secondary windings is used to transfer noise. It could not be reduced to the extent that it did not occur. Therefore, it was still inadequate as a disturbance wave prevention type transformer.

Regarding this type of transformer, Japanese Patent Publication No.
9-41297 and Japanese Utility Model Application Laid-Open No. 54-84523.
Although the structure is also described in the publications of all the publications, in any of the publications, even though there is a description that the shield plate and the outer box are integrally connected by screws or the like, no specific structure is shown. It has not been.

The present invention has been made to solve the above-mentioned conventional drawbacks. The object of the present invention is to easily fix the peripheral edge of the shield plate to the wall surface of the outer box and to obtain a good electric power. An object of the present invention is to provide a transformer for preventing disturbance wave, which can be fixed in a statically connected state and in a state in which no gap is generated.

[0010]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention divides the outer box enclosing the transformer main body into two divided bodies substantially at the position of the shield plate, and between the divided edges. By arranging the peripheral edge of the shield plate and integrally connecting both divided bodies from the outside with a connecting member, the peripheral edge of the shield plate is fixed to the divided edges of both divided bodies.

[0011]

[Operation] Since it is configured as described above, the peripheral edges of the shield plate can be fixed to the divided edges of the two divided bodies by integrally connecting the two divided bodies with the connecting member. It can be easily fixed on the wall of the outer box.
Moreover, since the peripheral edge of the shielding plate is arranged between the divided edges of both divided bodies, it is fixed closely to the divided edges of the divided bodies, so that the shielding plate is in good electrical connection with the outer box, and It can be fixed in a state where there is no gap.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the drawings. A is a transformer body, and B is an outer box that encloses the transformer body A. That is, in the transformer main body A, the primary winding 21 is wound around one of the yoke portions 11a and 11b of the iron core 10 formed by layering a silicon steel plate having a low high-frequency effective magnetic permeability, Further, each winding portion 22 of the secondary winding 22 is formed of two winding portions 22a and 22b formed so as to have the same inductance on both leg portions 12a and 12b.
a and 22b are wound, and a conductive shield plate 30 made of a non-magnetic material such as aluminum is removed between the primary winding 21 and the winding portions 22a and 22b of the secondary winding except for the iron core 10. It is configured by arranging. Reference numerals 23 and 24 denote lead wires of the windings 21 and 22, and reference numerals 25 and 26 denote mounting legs to the outer box B fixed to the lower portion of the iron core 10.

In the above description, although not shown, the winding portions 22a and 22b of the primary winding 21 and the secondary winding 22 have their outer surfaces entirely covered with a good conductor to prevent noise from being transmitted by electromagnetic radiation. is doing. The winding parts 22a and 22b of the secondary winding 22 are connected in parallel or in series. In this case, for example, the winding part 22a is left-handed and the winding part 22b is right-handed so that the polarities thereof match when connected. In addition, the shielding plate 30 inserts the E-shaped plate piece 31a from one side to the other side of the iron core 10, and superimposes the I-shaped plate piece 31b on the tip of the plate piece 31a. Aluminum foil 32 is connected to the peripheral portions of 31a and the I-shaped plate piece 31b by soldering or welding so that the peripheral edge extends to the outside of the wall surface of the outer box A. In that case, E-shaped plate piece 31a and I-shaped plate piece 31
b is arranged so that no gap is formed between the outer peripheral surface of the iron core 10 and one end of the I-shaped plate piece 31b and the E-shaped plate piece 31b.
Aluminum foil 32 at the overlapping portion of a and at that portion
The overlapping portions are overlapped with each other through the insulating layer 33 so that the shield plate 30 does not form a closed circuit of current.

On the other hand, the outer case B is formed of a conductive material into a rectangular parallelepiped, and the wall surface of the outer case B is divided substantially at the position of the shield plate 30 of the transformer main body A, whereby the two divided bodies 4 are formed.
It is set to 0a and 40b. And each divided body 40a, 40
Collar pieces 42a, 43a, 42b, 43b are provided outwardly on the divided edges 41a, 41b on the two opposite sides of b, and bolt holes 44a, 44b are arranged in rows on the respective collar pieces. Reference numerals 45 and 46 denote strip-shaped plate pieces abutting the wall surfaces of the other two sides of the two divided bodies 40a and 40b facing each other when the two divided bodies 40a and 40b are joined, and screw holes 47 and 48 are formed on both side edges in the longitudinal direction. In addition, screw holes 49 and 50 are provided in rows at the positions where the wall surfaces of the two divided bodies 40a and 40b are attached, at positions that match the screw holes 47 and 48, respectively. Reference numerals 51 and 52 are lead-out wire lead-out holes formed on the opposing wall surfaces of the divided bodies 40a and 40b.

In order to cover the transformer main body A constructed as described above with the outer case B, first, one of the divided bodies 40a of the outer case B is to be covered.
The transformer main body A is housed and fixed therein, and the peripheral edge of the shield plate 30 of the transformer main body A is divided into the divided edges 41 of the divided body 40a.
Position on a. Next, the division edge 41 of the divided body 40a
Both of the divided bodies 40a and 40b are abutted so that the divided edge 41b of the other divided body 40b coincides with each other, and then both divided bodies 4 are joined together.
0a, 40b, a bolt 53 is inserted into the bolt holes 44a, 44b of the collar pieces 42a, 43a, 42b, 43b, and a nut 54 is screwed into the bolt 53, while the other divided members 40a, 40b are tightened. 4 pieces on 2 sides
5, 46 are spliced and penetrated through the screw holes 47, 48, and screws (not shown) are screwed into the screw holes 49, 50.

By doing so, the divided body 40
At the locations of the collar pieces 42a, 43a, 42b, 43b of a, 40b, the dividing edges 41a, 41b of the divided bodies 40a, 40b.
The peripheral edge of the shield plate 30 is tightly fixed to the flange pieces 42a, 43a, 42b, 43b by pinching the peripheral edge of the shield plate 30 with the flange pieces 42a, 43a, 42b, 43b. In the place where 45 and 46 are attached, the peripheral edge of the shield plate 30 protruding outwardly from the wall surfaces of the two divided bodies 40a and 40b is pinched by the wall surfaces of the divided bodies 40a and 40b and the plate pieces 45 and 46. The periphery of the shield plate 30 is the divided body 40.
The primary winding chamber 1 is closely fixed to the dividing edges 41a and 41b of the a and 40b, and the inside of the outer box B is covered by the shield plate 30.
And the secondary winding chamber 2. The lead wire 23 of the primary winding 21 is led out from the lead-out hole 51, and the lead wire 24 of the secondary winding 22 is led out from the lead-out hole 52.

In the above, two of the windings 21 and 22 are
The case where the transformer main body A is formed by dividing the next winding 22 into two winding portions 22a and 22b and winding the windings 21 and 22 around the iron core 10 as described above is shown. Besides, as shown in FIG. 3, for example, one leg 12a of the iron core 10 is provided with the primary winding 21 and the other leg 12b is provided.
The transformer main body A may be configured by winding the secondary winding 22 on the outer case B. In such a configuration, the outer box B is divided into left and right parts.

Further, in the above case, both split bodies 40 of the outer box B
a and 40b are provided with flange pieces 42a, 43a, and 4 on their two opposite sides.
2b and 43b, and the other two opposite sides are plate pieces 45 and 4
Although it is configured such that they are integrally coupled by coupling through the six, the four sides of both divided bodies may be coupled through a flange piece or a plate piece, and the coupling means of both divided bodies has the above-described configuration. It is not limited to.

In the above case, the shield plate 30 is made up of the plate piece 31.
Although the aluminum foil 32 is connected to the peripheral portions of a and 31b, the peripheral edge portion of the shielding plate is formed in a flexible state in such a configuration, so that it is fixed to the outer box. It is extremely easy to pinch between the brim pieces or between the wall surface of the divided body and the plate piece, and there is an advantage that the peripheral edge of the shielding plate can be more easily fixed to the wall surface of the outer box.

[0020]

[Effect of the Invention] As described above, according to the present invention,
The outer box that encloses the transformer body is divided into two divisions at the position of the shield plate, and the periphery of the shield plate is arranged between the divided edges.
Since the peripheral edges of the shielding plate were fixed to the dividing edges of both divided bodies by integrally connecting both divided bodies from the outside with a connecting member, it is necessary to fix the peripheral edge of the shielding plate to the wall surface of the outer box. Easy to do from the outside.

Moreover, since the peripheral edge of the shield plate is disposed between the divided edges of both divided bodies, the shield plate comes into close contact with the divided body due to the coupling of both divided bodies, and a good electrical connection state is achieved. Can be fixed. Therefore, the electric resistance of the fixed portion becomes small, so that the shield plate has almost the same potential as that of the outer box, and the noise shield effect of the shield plate can be enhanced.

Moreover, since the shield plate is fixed to both of the divided bodies in a state where the peripheral edge is arranged between the divided edges of the divided bodies, a gap is generated during the fixing and the transformer is used for a long period of time. There is no possibility that a gap will be generated at the fixed portion during the operation, so that the stray capacitance between the primary winding and the secondary winding can be maintained at a small value for a long period of time.

Since the shield plate and the divided body are in intimate contact with each other, the heat dissipation effect of the transformer main body through the shield plate and the outer case is promoted.

Therefore, according to the present invention, it is possible to provide at low cost a disturbance wave prevention type transformer having an excellent noise blocking effect.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of the assembly of FIG. 1 assembled.

FIG. 3 is a vertical cross-sectional view showing another embodiment of the present invention.

[Explanation of Codes] A Transformer Main Body B Outer Box 10 Iron Core 21 Primary Winding 22 Secondary Winding 30 Shielding Plate 40a 40b Dividing Body 41a 41b Dividing Edge 45 46 Coupling Member (Strip-shaped Plate Piece) 53 Coupling Member (Bolt) ) 54 coupling member (nut)

Claims (1)

[Scope of utility model registration request] 1. A primary winding 21 and a secondary winding 22 are wound at different locations on an iron core 10, and the primary winding 21 and the secondary winding 2 are wound.
In the transformer in which the transformer body A having the shield plate 30 disposed between the two is covered by the outer box B, the outer box B is divided into two divided bodies 40a and 40b at the position of the shield plate 30. ,
The peripheral edge of the shielding plate 30 is arranged between the divided edges 41a and 41b, and the divided bodies 40a and 40b are integrally coupled from the outside by a coupling member, whereby the shielding plate 30 is formed.
Are divided edges 41a, 41 of the two divided bodies 40a, 40b.
Obstacle prevention type transformer fixed to b.