JPH08316052A - Foil winding transformer - Google Patents

Abstract

PURPOSE: To enhance the cooling efficiency of foil winding by forming a cooling duct of a punching metal aluminum corrugated board having holes for passing a cooling medium and feeding the cooling medium in the circumferential direction of foil winding through the holes thereby suppressing generation of eddy current. CONSTITUTION: An aluminum corrugated board 2, made of a punching metal aluminum plate, is sandwiched between foil windings 1 each comprising a laminate of an insulating sheet and a metal sheet thus forming a passage of cooling medium 3, i.e., a cooling duct 4. The cooling medium 3 is fed in the circumferential direction of foil winding 1 through holes 5 made in the aluminum corrugated board 2 thus enhancing the cooling efficiency. The foil winding 1 is retained in the axial direction by means of a coil retainer 6 and wound around a core thus constituting a foil winding transformer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foil winding transformer, and more particularly to the structure of a cooling duct for windings of a foil winding transformer.

[0002]

2. Description of the Related Art Conventionally, a foil winding of a transformer is cooled by using a corrugated board made of an aluminum plate as a coolant passage by winding an insulating sheet and a metal sheet in a wound winding. The duct is formed to increase the apparent cooling area and improve the cooling efficiency.

FIG. 3 is a fragmentary perspective view showing a structure of a cooling duct of a foil winding of a foil winding transformer. In FIG. 3, a foil winding 1 in which an insulating sheet and a metal sheet are superposed and wound. Inside,
A corrugated board 8 made of an aluminum plate is wound to form a cooling duct 4 which serves as a passage for the refrigerant 3, and a coil presser 6 presses the foil winding 1 in its axial direction to wind it around an iron core (not shown). It constitutes a foil winding transformer.

[0004]

In the foil winding transformer described in the prior art, as shown in the development view of FIG. 4, which shows the flow of the refrigerant 3 in the corrugated board portion of the cooling duct 4 of the conventional foil winding. In addition, due to its structure, a part of the cooling duct 4 is blocked by the coil retainer 6, and the flow of the coolant 3 does not occur at the portion where the inlet / outlet is blocked by the coil retainer 6, so that the coolant 3 is replaced. However, there is a problem that a difficult portion is formed as compared with the other cooling ducts 4 and in some cases, it causes local heating.

As a solution to the above-mentioned problems, as shown in the cross-sectional view of the main part showing the notch groove of the coil presser of the foil winding of FIG.
A method of arranging the cutout groove 9 along the cooling duct 4 in the coil retainer 6 is conceivable, but the cutout groove 9 is formed in the curvature of the cooling duct 4.
It is difficult to match the curvatures of the
By forming the notch groove 9 in the inner wall of the cooling duct 4, there arises a problem that the support of the aluminum corrugated board 8 inside the cooling duct 4 is lost.

Like the foil-shaped conductor, the aluminum corrugated board 8 also causes an eddy current loss due to the passage of leakage flux, so that the heat generation of the aluminum corrugated board 8 itself becomes a problem.

The present invention has been made in view of the above problems of the prior art, and an aluminum corrugated board made of a punching metal aluminum plate forms a cooling duct which is a passage for a refrigerant. This reduces the amount of eddy current generated inside the aluminum corrugated board due to the leakage flux, and the refrigerant passage holes in the aluminum corrugated board enable the refrigerant to move in the circumferential direction of the foil winding. An object of the present invention is to provide a compact foil winding transformer by improving the cooling efficiency of the wire.

[0008]

In order to achieve the above-mentioned object, a foil winding transformer according to the present invention comprises a punching metal-like aluminum inside a foil winding in which an insulating sheet and a metal sheet are superposed and wound. An aluminum corrugated board made of aluminum plate is wound to form a cooling duct that serves as a refrigerant passage.

[0009]

As described above, by forming the cooling duct with the aluminum corrugated board made of the punched metal aluminum plate, the amount of eddy current generated inside the aluminum corrugated board due to the leakage flux can be reduced. By allowing the refrigerant to move in the circumferential direction, the cooling efficiency of the foil winding is improved, and a compact foil winding transformer can be obtained.

[0010]

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

FIG. 1 is a cutaway perspective view showing an embodiment of a cooling duct of a foil winding transformer of the present invention. In FIG. 1, a foil winding 1 in which an insulating sheet and a metal sheet are superposed and wound. An aluminum corrugated board 2 made of a punched metal aluminum plate is wound inside to form a cooling duct 4 which serves as a passage for the refrigerant 3, and a cooling medium passage hole 5 of the aluminum corrugated board 2 forms a foil winding 1 of the foil winding 1. The cooling efficiency is improved by allowing the refrigerant 3 to move in the circumferential direction, and the coil winding 6 holds the foil winding 1 in its axial direction and winds it around an iron core (not shown) to form a foil winding transformer. ing.

FIG. 2 is a development view of the corrugated board of the cooling duct shown in FIG. 1. As shown in FIG. 2, since the aluminum corrugated board 2 is made of a punching metal aluminum plate, the aluminum corrugated board is used. Since the cooling medium passage holes 5 through which the cooling medium 3 can pass in the circumferential direction are provided at various places in the cooling duct 4 divided by the partition portion 7 of 2, the inlet and outlet of the cooling medium 3 is blocked by the coil retainer 6. Refrigerant 3 also inside the cooling duct 4 of the part
Is generated, and the cooling efficiency is improved.

[0013]

Since the present invention is configured as described above, the following effects can be obtained.

Since the refrigerant can move in the circumferential direction,
The cooling efficiency can be improved because the refrigerant can be replaced in the portion where the inlet / outlet of the cooling duct is conventionally blocked by the coil retainer and the refrigerant flow is made uniform.

By adopting the aluminum corrugated body made of punching metal, the eddy current loss due to the leakage magnetic flux interlinking with the aluminum corrugated body is reduced, and the heat generation of the aluminum corrugated body itself is reduced.

By making the flow of the refrigerant uniform and reducing the eddy current loss of the aluminum corrugated to reduce the temperature rise of the winding, the transformer as a whole can be made compact.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part showing an embodiment of a cooling duct of a foil winding transformer of the present invention.

2 is a development view of a corrugated board of the cooling duct of FIG. 1. FIG.

FIG. 3 is a fragmentary perspective view showing a structure of a cooling duct for a foil winding of a foil winding transformer.

FIG. 4 is a development view showing a flow of a refrigerant in a corrugated board portion of a conventional foil winding cooling duct.

FIG. 5 is a sectional view of an essential part showing a cutout groove of a coil presser of a conventional foil winding.

[Explanation of symbols]

 1 ... Foil winding 2 ... Aluminum corrugated board 3 ... Refrigerant 4 ... Cooling duct 5 ... Refrigerant passage hole 6 ... Coil retainer 7 ... Partition

Claims (1)

[Claims] 1. A foil winding transformer comprising a foil winding formed by stacking an insulating sheet and a metal sheet and winding the corrugated board inside the foil winding to form a cooling duct as a refrigerant passage. A cooling duct is formed by the aluminum corrugated board made of the punched metal aluminum plate, and the refrigerant passage hole of this aluminum corrugated board enables the refrigerant to move in the circumferential direction of the foil winding. Foil winding transformer.