JP3283997B2 - Mold coil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded coil formed by resin-molding a multi-tubular coil.

[0002]

2. Description of the Related Art A molded coil has excellent electrical and mechanical characteristics and is used as a winding of a molded transformer or a molded reactor. When the capacity is increased by the transformer or the like, the heat generated by the coil increases. Therefore, it is necessary to suppress the heat generation. Therefore, a cooling air duct is formed in the coil. In this case, the coil is formed in a multi-tubular configuration in which a plurality of coils are concentrically stacked in a cylindrical shape, and when the coil is resin-molded, an air duct is formed in a portion between the coil layers. However, since partial discharge is more likely to occur in the air duct portion than in the resin mold layer portion, it is necessary to weaken the electric field between the coil layers.

In this connection, in the U-connection winding shown in FIG. 6 in which the lower and lower portions of the coil layer 1a of the coil 1 and the upper and upper portions are connected alternately with the crossover wires 2 sequentially, the adjacent coil layer 1a
Is applied to the two layers of the coil layer 1a, unless the dimensions of the coil 1 are reduced,
The electric field between them cannot be weakened.

On the other hand, in an N-connection winding shown in FIG. 7 in which only the upper and lower portions (or lower and upper portions) of a coil layer 11a of a coil 11 are sequentially connected by a crossover wire 12, an interlayer between adjacent coil layers 11a is formed. Can be applied to one coil layer 11a, the electric field between the coil layers 11a can be reduced without reducing the size of the coil 11.

[0005]

However, in the case of the N-connection winding, since the connecting wire 12 passes outside the coil 11,
Since it is necessary to secure an insulating distance from a tank (not shown), and furthermore, from the ground that the tank is grounded, the tank must be largely separated from the coil 11, resulting in an increase in the size of the entire device.

The connecting wire 12 extending outside the coil 11 is cut off between the coil layers 11a when the coil 11 is wound, and then separately connected. At the same time, there is a problem that it is difficult to sufficiently obtain connection reliability.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and therefore has an object to not only reduce the electric field between the coil layers without reducing the dimensions of the coil, but also to reduce the size of the entire device. It is still another object of the present invention to provide a molded coil capable of shortening manufacturing time and improving reliability.

[0008]

In order to achieve the above object, in a molded coil according to the present invention, a plurality of coils are provided in a cylindrical shape so as to be concentrically stacked, and an air duct is formed between the layers. In a resin molded product, a crossover connecting the coil to the N between the coil layers is provided between the coil layers, and a plurality of air ducts are provided.
Formed with the spacers, and the spacers
It is characterized by being held at a predetermined distance from the layer .

In this case, the air duct may be formed by a corrugated spacer, and the crossover may be held at a predetermined distance from the coil layer by the spacer. Further, the coil holding surfaces of these spacers are preferably inclined.

[0010]

According to the above means, not only can the coil be N-connected, but also a connecting crossover can be positioned between the coil layers so as not to project outside, and the coil can be cut between the layers. It can be wound continuously without forming a crossover, and
Insulation of all parts using spacers for air duct formation
Therefore, it is possible to secure better.

The air duct is formed by a corrugated spacer.
The spacer is used to move the crossover wire a predetermined distance from the coil layer.
If it is held as if it were placed,
Better insulation properties can be ensured.

In this case, if the coil holding surfaces of the spacers are inclined, the crossover can be held so that the distance from the coil layer to the coil layer becomes gradually larger in accordance with the potential difference therebetween, and partial discharge occurs more. It is possible to reduce the size of the air duct at the crossover portion while reducing the size.

[0013]

[0014]

EXAMPLES Hereinafter, the first embodiment of the present invention, and FIG 1
This will be described with reference to FIG . First, FIG. 2 shows an iron core 21 and
A high-voltage coil 22 provided around the periphery thereof and a low-voltage coil 23 further provided therearound are shown.

As shown in detail in FIG. 1, the low-voltage coil 23 is formed by winding a coil layer 23a into a cylindrical shape, and a plurality of such coil layers 23a are concentrically overlapped via a spacer (not shown). It is wound continuously and provided,
The connecting wires 24 to be connected are provided between the coil layers 23a, and in this state, a resin mold layer 26 is formed by resin molding using, for example, epoxy resin so as to form an air duct 25 between the coil layers 23a. Make up. In this case, the crossovers 24 are each located in the air duct 25.

According to the above configuration, since the coil layers 23a of the coil 23 are N-connected, the voltage applied between adjacent coil layers 23a is applied to one layer of the coil layers 23a in the same manner as in the conventional N-connection. Minutes, so
Without reducing the size of the coil 23, the coil layer 23
The electric field between "a" and "a" can be weakened, and partial discharge can hardly occur.

In this case, the connecting wire 24 is connected to the coil layer 23.
a, the tank can be prevented from protruding to the outside, so that the insulation distance can be secured without separating the tank from the coil 24 as much as the conventional one, and the size of the entire device can be reduced accordingly. Can be achieved.

Furthermore, since the coil 23 can be wound continuously without cutting between the coil layers 23a to form the crossover wire 24, no time is required for connecting the coil as in the conventional case. In addition, the manufacturing time can be shortened, and at the same time, the reliability of the connection can be improved.

In FIG . 3, an air duct 25 is formed by a plurality of spacers 27, and one of the spacers 27a
In contrast, a spacer 27b is provided so that the crossover wire 24 is sandwiched therebetween, and is held at a predetermined distance from the coil layer 23a, particularly a distance that does not cause partial discharge even between the coil layer 23b and the crossover wire 24. In this manner, the insulation property of the crossover wire 24 can be more preferably secured by using the spacers 27 (spacers 27a and 27b) for forming the air duct 25.

FIG. 4 shows a second embodiment of the present invention.
The air duct 25 is formed by a corrugated spacer 28, and a short corrugated spacer 28b is provided for a part 28a of the spacer 28 in the winding direction of the coil layer 23a, and the connecting wire 24 is sandwiched therebetween. As described above, the coil layer 23a is held so as to maintain a distance that does not cause partial discharge even between the coil layer 23a and the crossover wire 24, and the same effect as described above can be obtained. is there.

FIG. 5 shows a third embodiment of the present invention.
The air duct 25 is formed by a plurality of spacers 29, and a spacer 29b is provided for one of the spacers 29a, and the crossover wire 24 is formed by the slopes 30 and 31 so that the distance from the coil layer 23a is reduced by the potential difference between them. In this case, the coil is sandwiched so as to gradually increase in size, thereby holding the coil layer 23a and the crossover wire 24 so that partial discharge does not occur. In this case, the crossover 24
The size of the air duct 25 in the portion can be made smaller than that of the second embodiment, and the size of the entire device can be further reduced. This structure can be applied to the spacer having the waveform shown in the second embodiment.

[0022]

[0023]

The molded coil of the present invention is as described above, and has the following effects. First, a coil is formed by concentrically stacking a plurality of layers in a cylindrical shape, and is formed by resin molding so as to form an air duct between the layers. The coil is provided between the coil layers and over the layers. Arrange crossovers for N connection and duplicate air ducts.
It is formed with several spacers, and the crossover is coiled with these spacers.
By holding it at a predetermined distance from the
The electric field between the coil layers can be weakened without reducing the dimensions of the coil, and the size of the entire device can be reduced.
In addition to shortening the manufacturing time and improving reliability , the insulation of the crossover is improved by forming an air duct.
Can be better secured by using spacers for
Wear.

[0024]

Second , by forming the air duct with a corrugated spacer and holding the crossover at a predetermined distance from the coil layer with the spacer, the insulation property of the crossover can be improved as described above. By using the spacer for formation, it is possible to secure better.

Third , by making the coil holding surface of the spacer a slope, the crossover can be held so that the distance from the coil layer to the coil layer becomes gradually larger in accordance with the potential difference between them, and more partial discharge occurs. It is possible to reduce the size of the air duct in the crossover portion, and to further reduce the size of the entire device.

[0027]

[Brief description of the drawings]

FIG. 1 is a cutaway perspective view of a main part showing a first embodiment of the present invention.

FIG. 2 is an overall vertical sectional view.

FIG. 3 is a cutaway perspective view of another main part.

FIG. 4 is a view corresponding to FIG. 1 showing a second embodiment of the present invention;

FIG. 5 is a diagram corresponding to FIG. 1 showing a third embodiment of the present invention.

FIG. 6 is a diagram corresponding to FIG. 2 showing a conventional example.

FIG. 7 is an equivalent view of FIG. 2 showing a different conventional example.

[Explanation of symbols]

23 is a low voltage coil (coil), 23a is a coil layer, 24
Is a crossover, 25 is an air duct, 26 is a resin mold layer,
27, 27a, 27b are spacers, 28, 28a, 28b are spacers, 29, 29a, 29b are spacers, 30, 31
Indicates a slope.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-54-23962 (JP, A) JP-A-55-99709 (JP, A) JP-A-52-151357 (JP, A) JP-A-57-19757 194515 (JP, A) Japanese Utility Model Showa 53-95106 (JP, U) Japanese Utility Model Showa 60-146327 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01F 27 / 28,27 / 32

Claims (3)

(57) [Claims] 1. A coil comprising a plurality of coils which are formed in a cylindrical shape and concentrically overlapped with each other, and which are resin-molded so as to form an air duct between the layers, wherein the coils are provided between the coil layers and between the coil layers. A mold coil, wherein a crossover wire for N connection is provided, and an air duct is formed by a plurality of spacers, and the crossover wire is held by the spacers at a predetermined distance from the coil layer. 2. A coil comprising a plurality of coils which are formed in a cylindrical shape and concentrically overlapped with each other, and which are resin-molded so as to form an air duct between the layers, wherein the coils are provided between the coil layers. A mold coil, wherein a crossover wire for N-connection is provided and an air duct is formed by a corrugated spacer, and the crossover wire is held at a predetermined distance from the coil layer by the spacer. 3. The molded coil according to claim 1, wherein the coil holding surface of the spacer is a slope.