Cooling structure for coil component

A coil device with a cooling structure includes: a coil unit that has a core structure having one or more leg parts and one or more coils wound around the one or more leg parts; and a flow-rectifying member having a flat plate portion covering a face of the one or more coils and flow-rectifying ribs inwardly protruding from an inner surface of the flat plate portion, the flow-rectifying ribs extending in a direction parallel to center axes of the one or more coils and being positioned to face side boundaries of the face of the one or more coils. The flat plate portion and the flow-rectifying ribs form a first air cooling channel at a substantially uniform gap outside of the one or more coils along the direction parallel to the center axes thereof, the first air cooling channel passing cooling air to air-cool the one or more coils.

BACKGROUND OF THE INVENTION

Technical Field

The present invention relates to a cooling structure for air cooling coil units such as transformers or reactors.

Background Art

FIGS. 5A to 5Cshow a core-type reactor described in Patent Document 1:FIG. 5Ais a plan view,FIG. 5Bis a front view, andFIG. 5Cis a right side view.

In these drawings, reference number101is the core structure, and coils102and103are wound around the pair of leg parts of the core structure. A flow-rectifying member104made of an insulating material is also disposed so as to surround a portion of the coils102and103in the axial direction.

FIG. 6is a plan view for describing the cooling effects of this conventional technology. Reference numbers101aand101bindicate magnetic gaps formed in the core structure101.

InFIG. 6, when a high-frequency current flows to the coils102and103, not only does the temperature of the coils102and103increase, but so does the temperature of the core structure101having the magnetic gaps101aand101b.

In the structure shown inFIG. 6, the flow-rectifying member104is disposed such that the axial-direction end104aof the flow-rectifying member104protrudes from an end101cof the core structure101. This forms an airflow A of cooling air along the inner surface of the end104a, and a portion of this airflow A becomes airflows B1and B2, which pass through gaps102aand103abetween the coils102&103and the leg parts of the core structure101.

In the conventional technology, these airflows A, B1, and B2cool the coils102&103and the core structure101.

RELATED ART DOCUMENT

Patent Document

SUMMARY OF THE INVENTION

As shown inFIG. 6, the airflow A primarily flows around the core structure101and inside the flow-rectifying member104in the direction of the coils102and103. Thus, in terms of the cooling air flowing between the coils102&103and the core structure101, the airflow B1is dominant and the internal airflow B2is insignificant, and there is also little airflow flowing through the gaps between the coils102and103.

Accordingly, in the conventional technology, it was difficult to uniformly and sufficiently cool the coils102&103and the core structure101.

As a countermeasure, a solution of the present invention is to provide a cooling structure for a coil unit that makes the resistances of the flow channels for the cooling air around the coils uniform in order to efficiently and uniformly cool the coils and cooling structure. Accordingly, the present invention is directed to a scheme that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, in one aspect, the present disclosure provides a coil device with a cooling structure, including:

a coil unit that has a core structure having one or more leg parts and one or more coils wound around the one or more leg parts; and

a flow-rectifying member having a flat plate portion covering a face of the one or more coils and flow-rectifying ribs inwardly protruding from an inner surface of the flat plate portion, the flow-rectifying ribs extending in a direction parallel to center axes of the one or more coils and being positioned to face side boundaries of the face of the one or more coils,

wherein the flat plate portion and the flow-rectifying ribs form a first air cooling channel at a substantially uniform gap on an outside of the one or more coils along the direction parallel to the center axes of the one or more coils, the first air cooling channel passing cooling air therethrough so as to air-cool the one or more coils.

In one aspect, it is preferable that the flow-rectifying ribs each have a substantially triangular shape in a cross section taken along a direction perpendicular to the center axes of the one or more coils.

Furthermore, in one aspect, a second air cooling channel may be formed between an inner surface of each of the one or more coils and a surface of each of the one or more leg parts around which the one or more coils is wound, the second air cooling channel having a substantially uniform gap.

In one aspect, the present invention is applicable to a reactor or transformer having the one or more coils respectively wound around a plurality of leg parts of the core structure, for example.

The present invention makes it possible to efficiently and uniformly cool an entire coiled component by attaching a flow-rectifying member having flow-rectifying ribs to the coiled component in order to form a first cooling air channel around the coils, the cooling air then being passed through this channel.

This allows the capacity of a cooling device, such as a cooling fan, to be small, which makes it possible to reduce the total size and cost of a device having coil units embedded therein.

DETAILED DESCRIPTION OF EMBODIMENTS

An embodiment of the present invention will be explained below with reference to the drawings. This embodiment is the present invention as applied to a shell-type reactor, which is a coil unit;FIG. 1is an exploded perspective view of the reactor, andFIG. 2is a plan view of the assembly state.

InFIGS. 1 and 2, reference number10is the shell-type reactor, which is the coil unit of a coil device, and this shell-type reactor has three phase coils11,12, and13and a core structure14in which these coils11,12, and13are wound. The core structure14of the coil device has three leg parts respectively disposed in the centers of the coils11,12, and13, and two leg parts disposed outside the coils11and13.

Reference number16is an output conductor for connecting the coils11,12, and13to an external conductor (not shown).

Furthermore, reference numbers50A and50B are flow-rectifying members attached from both sides of the coils11,12, and13so as to sandwich the coils11,12, and13. These flow-rectifying members50A and50B include a rectangular flat plate portion51covering the side faces of the coils11,12, and13, fixing ends52formed on both ends of the flat plate portion, and flow-rectifying ribs53a,53b,53c, and53dformed on the inner surface of the flat plate portion51(i.e., on the surface of the flat plate portion facing the coils11,12, and13).

As shown inFIG. 2, the flow-rectifying ribs53a,53b,53c, and53dare formed to have an approximately triangular cross section so as to face the corner portions15a,15b,15c, and15dof the outer peripheral surfaces of the coils11,12, and13while maintaining a uniform gap therebetween. These flow-rectifying ribs53a,53b,53c, and53dare protrusion-shaped members that are parallel to the center axes of the coils11,12, and13and longer than the axial direction length of the coils11,12, and13.

The flow-rectifying members50A and50B containing the flow-rectifying ribs53a,53b,53c, and53dare each entirely and integrally fabricated of a resin or metal material.

FIG. 3is a perspective view of a reactor formed by combining the reactor10and the flow-rectifying members50A and50B. The flow-rectifying members50A and50B are attached to the outer leg parts14aand14eof the core structure14on both sides of the reactor10by an adhesive, spot welding, or the like.

FIG. 4Ais front view in which a portion of the flat plate portion51of the flow-rectifying member50B has been cut out,FIG. 4Bis a cross-sectional view along line A-A ofFIG. 4A, andFIG. 4Cis a cross-sectional view along line B-B. Hatching to indicate a cross section has been omitted for convenience.

As shown inFIG. 4B, gaps that will serve as first cooling air channels17(or tunnels; the shaded portions) are maintained between the coils11,12, and13, between the outer leg part14aand the outer peripheral surface of the coil11, and between the outer leg part14eand the outer peripheral surface of the coil13. InFIG. 4B, the reference numbers14b,14c, and14dare each leg parts around which the coils11,12, and13are wound.

In this embodiment, as shown inFIG. 4A, when cooling air generated by a cooling fan etc. (not shown) is supplied from below the reactor, the resulting airflow passes through the cooling air channels17formed on the outer peripheral surfaces of the coils11,12, &13and flows towards the output conductors16.

In the present embodiment, the flow-rectifying members50A and50B, which include the flat plate portions51and flow-rectifying ribs53a,53b,53c, and53d, are attached between the leg parts14aand14eand sandwich the coils11,12, and13from both sides. As shown inFIG. 4B, this forms the first cooling air channels17on the outer peripheral surfaces of the coils11,12, and13at generally uniform widths along the direction perpendicular to the center axes of the coils. As a result, the resistances of the flow channels around the coils11,12, and13become generally uniform, and the cooling air passes evenly across the outer peripheral surfaces of the coils11,12, and13; thus, the coils11,12, and13can each be uniformly cooled from outside.

Furthermore, by forming second cooling air channels18(or tunnels) between the inner peripheral surfaces of the coils11,12, &13and the outer peripheral surfaces of the leg parts14b,14c, and14dat generally uniform widths along the direction perpendicular to the center axes of the coils11,12, and13, it is possible to cool the inner peripheral surfaces of the coils11,12, &13and the outer peripheral surfaces of the leg parts14b,14c, and14d.

In other words, the first cooling air channels17and the second cooling air channels18cool the coils11,12, &13from inside and outside and can uniformly cool the leg parts14a,14b,14c,14d, and14e.

INDUSTRIAL APPLICABILITY

The present invention is applicable as a cooling structure for various types of single-phase, multi-phase, core-type, or shell-type coil units having coils and a core structure, such as a transformer, reactor, or the like.