JP2008112818A - Reactor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reactor having an excellent heat dissipating property regarding the reactor having a coil, a core filled on the inside and outer periphery of the coil and a case housing the coil and the core inside. <P>SOLUTION: The reactor 1 has the coils 2 generating magnetic flux by electric conduction, the core 3 formed with magnetic-powder mixed resin filled on the inside and outer peripheries of the coils 2 and the case 4 housing the coils 2 and the core 3 inside. The case 4 is composed of a vessel section 40 with an opening section 43 and a cover section 5 closing the opening section 43 of the vessel section 40. The cover section 5 has internal fins 51 projected to the inside of the case 4. At least some of the internal fins 51 are embedded into the core 3. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a reactor having a coil, a core filled inside and on the outer periphery of the coil, and a case for housing the coil and the core inside.

The reactor includes, for example, a core made of a magnetic material and a coil wound around the core. And the magnetic flux along a core is formed by supplying with electricity to a coil.
When the coil is energized and the reactor is operated, Joule heat is generated from the coil. Further, heat is generated in the core as magnetic flux is formed in the inner and outer cores of the coil. If the temperature of the reactor rises too much due to these heat generations, the stability of the operation of the reactor may be impaired. Moreover, the temperature of the electronic components around the reactor may increase, and the operation stability of the surrounding electronic components may be impaired.
As a result, there is a risk of impairing the operational stability of a power converter or the like that incorporates such a reactor.

Then, in order to suppress the temperature rise of a reactor, the reactor with a cooler which accommodated the reactor in the case which served as the cooler is proposed (refer patent document 1).
However, in the reactor with a cooler, the cooler is disposed only on the lower surface of the reactor, and no cooling means is provided on the upper surface side of the reactor. Therefore, there is a problem that it is difficult to sufficiently improve the heat dissipation efficiency.

JP 2005-303212 A

  This invention is made | formed in view of this conventional problem, and aims at providing the reactor excellent in heat dissipation.

The present invention comprises a coil that generates magnetic flux when energized,
A core made of a magnetic powder mixed resin filled inside and outer periphery of the coil;
A case for accommodating the coil and the core inside;
The case includes a container portion having an opening and a lid portion that closes the opening of the container portion.
The lid portion has an inner fin protruding inside the case,
At least a part of the inner fin is in the reactor, which is embedded in the core (claim 1).

Next, the effects of the present invention will be described.
The lid portion of the reactor has the inner fin, and at least a part of the inner fin is embedded in the core. Therefore, the heat generated in the coil or core can be efficiently transmitted to the lid through the inner fin. The heat transmitted to the lid is radiated to the outside.
Thus, in the reactor, the heat dissipation efficiency can be improved by providing the lid with a heat dissipation function.
Moreover, since the said inner side fin is provided in the said cover part, the formation can be performed easily.

  As described above, according to the present invention, it is possible to provide a reactor excellent in heat dissipation.

In the present invention, the magnetic powder mixed resin is a material obtained by mixing magnetic powder into a resin. Examples of the magnetic powder include ferrite powder, iron powder, and silicon alloy iron powder. Moreover, as said resin, thermosetting resins, such as an epoxy resin, and a thermoplastic resin can be used, for example.
Moreover, a reactor can be used for power converters, such as a DC-DC converter and an inverter, etc., for example.

Moreover, it is preferable that the said cover part has an outer side fin which protrudes on the outer side of the said case (Claim 2).
In this case, the heat transmitted to the lid through the inner fin can be efficiently radiated to the outside through the outer fin. Therefore, a reactor having further excellent heat dissipation can be obtained.

Moreover, it is preferable that at least a part of the lid portion is provided with a corrugated portion, and a peak portion and a trough portion of the corrugated portion constitute the outer fin and the inner fin, respectively. (Claim 3).
In this case, the outer fin and the inner fin can be easily formed. That is, for example, the corrugated portion can be formed by forming a relatively thin metal plate into a corrugated shape by press working or the like.

Moreover, it is preferable that the lid portion is provided with a slit portion that is partially opened.
In this case, it can be easily confirmed whether or not the core is sufficiently filled in the case.

Moreover, it is preferable that the said core is partially arrange | positioned also outside the said cover part (Claim 5).
In this case, since the contact area between the lid and the core can be increased, more heat from the core can be transmitted to the lid. As a result, the heat dissipation efficiency can be further improved.

In addition, a plurality of the inner fins are formed, and one of the plurality of inner fins formed at a position farther from the winding than that formed at a position near the winding constituting the coil. Is preferably projecting greatly (Claim 6).
In this case, the amount of protrusion of the inner fin can be increased as much as possible while preventing the formation of magnetic flux by the coil. Thereby, cooling efficiency can be improved, maintaining the magnetic characteristic of a reactor.

(Example 1)
A reactor according to an embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, the reactor 1 of this example includes a coil 2 that generates magnetic flux when energized, a core 3 made of a magnetic powder mixed resin filled inside and outside the coil 2, and the coil 2 and the core 3 on the inside. And a case 4 accommodated in the housing.

The case 4 includes a container part 40 having an opening 43 and a lid part 5 that closes the opening 43 of the container part 40.
The lid 5 has an inner fin 51 that protrudes inside the case 4 and an outer fin 52 that protrudes outside the case 4.
At least a part of the inner fin 51 is embedded in the core 3.

As shown in FIGS. 1 and 2, the lid 5 is provided with a corrugated portion 53, and the crest and trough of the corrugated portion 53 constitute an outer fin 52 and an inner fin 51, respectively. ing.
As shown in FIG. 2, the lid portion 5 is provided with a slit portion 54 that is partially opened. A plurality of slit portions 54 are formed in a trough portion in the corrugated portion 53, that is, the inner fins 51 in a staggered manner.

  As shown in FIG. 1, the corrugated portion 53 has a core 3 partially disposed outside the lid portion 5. In the process of manufacturing the reactor 1, the core 3 arranged on the outside of the lid portion 5 overflows from the slit portion 54 formed on the lid portion 5 in the process of manufacturing the reactor 1. Be placed.

The container portion 40 of the case 4 includes a bottom surface portion 41 and a side surface portion 42 erected from the peripheral edge portion of the bottom surface portion 41. The lid portion 5 that closes the opening portion 43 of the container portion 40 is fixed by screws 57.
The case 4 is made of, for example, aluminum, for example, both the container 40 and the lid 5.
The lid portion 5 forms a corrugated portion 53 by pressing an aluminum plate having a thickness of about 1 mm.
And the formation pitch of the inner side fin 51 or the outer side fin 52 can be about 10 mm, for example.

Further, the protruding amount of the inner fin 51 is about 5 to 10 mm, and the protruding amount of the outer fin 52 is about 5 mm.
The inner fin 51 is formed in a substantially V shape, and the outer fin 52 is formed in a folded shape.
As shown in FIG. 2, the lid portion 5 has flat portions 55 on both sides of the corrugated portion 53, and screw holes 56 are formed in the flat portion 55.

Moreover, the reactor 1 can be used for power converters, such as a DC-DC converter and an inverter, etc., for example.
The magnetic powder mixed resin constituting the core 3 is a material obtained by mixing magnetic powder into the resin. Examples of the magnetic powder include ferrite powder, iron powder, and silicon alloy iron powder. As the resin, for example, a thermosetting resin such as an epoxy resin or a thermoplastic resin can be used.

Next, the manufacturing method of the reactor 1 of this example is demonstrated.
First, the coil 2 is set at a predetermined position in the container portion 40 of the case 4. Next, a magnetic powder mixed resin liquid that is a material of the core 3 is injected into the case 4.
Next, while the magnetic powder mixed resin liquid is not solidified, the lid 5 is placed over the opening 43 of the container 40 and fixed. At this time, a part of the inner fin 51 of the lid part 5 is buried in the magnetic powder mixed resin liquid in the container part 40. At this time, a part of the magnetic powder mixed resin liquid overflows upward from the slit portion 54 provided in the lid portion 5 and spreads to the upper side (outside) of the inner fin 51.

After a part of the magnetic powder mixed resin liquid has spread sufficiently to the upper side (outside) of the inner fin 51, the magnetic powder mixed resin liquid is solidified by holding at a predetermined heating temperature for a predetermined time to form the core 3.
Note that a lead lead portion (not shown) that is a winding end portion of the coil 2 protrudes to the outside of the core 3.

Next, the function and effect of this example will be described.
The lid portion 5 of the reactor 1 has an inner fin 51 and an outer fin 52, and a part of the inner fin 51 is embedded in the core 3. Therefore, the heat generated in the coil 2 and the core 3 can be efficiently transmitted to the lid portion 5 through the inner fins 51. The heat transmitted to the lid 5 can be efficiently radiated through the outer fins 52.
Thus, in the reactor 1, the heat dissipation efficiency can be improved by providing the lid 5 with a heat dissipation function.
In addition, since the inner fin 51 and the outer fin 52 are provided on the lid portion 5, the formation can be easily performed.

  Further, a corrugated portion 53 is provided in at least a part of the lid portion 5, and a peak portion and a trough portion of the corrugated portion 53 constitute an outer fin 52 and an inner fin 51, respectively. Thereby, the outer fin 52 and the inner fin 51 can be formed easily. That is, as described above, since the corrugated portion 53 can be formed by forming a metal plate having a relatively small thickness into a corrugated shape by press working, the processing is easy.

Moreover, since the slit part 54 opened partially is provided in the cover part 5, it can be confirmed easily whether the core 3 is fully filled in the case 4.
Further, the core 3 is partially disposed outside the lid 5 in the corrugated portion 53. Therefore, since the contact area between the lid 5 and the core 3 can be increased, more heat of the core 3 can be transmitted to the lid 5. As a result, the heat dissipation efficiency can be further improved.

  Further, by disposing a cooler (not shown) provided with a cooling water channel in contact with the container part 40, heat is radiated from the container part 40 by water cooling, and air cooling through the inner fin 51 and the outer fin 52 is performed from the lid part 5. It is also possible to dissipate heat. Thereby, the heat dissipation efficiency can be further improved.

  As described above, according to this example, it is possible to provide a reactor having excellent heat dissipation.

(Example 2)
This example is an example of the reactor 1 in which the corrugated portion 53 in the lid portion 5 is formed in a circular shape as shown in FIG.
That is, the inner fin 51 and the outer fin 52 are formed concentrically.
The corrugated portion 53 can be easily formed by pressing as in the first embodiment.
Others are the same as in the first embodiment.
Also in this example, it has the same effect as Example 1.

(Example 3)
In this example, as shown in FIGS. 4 and 5, among the plurality of inner fins 51, the inner fin 51 is formed at a position farther from the winding 21 than the one formed at a position near the winding 21 constituting the coil 2. It is an example of the reactor 1 in which the thing protrudes greatly.

That is, the inner fin 51 arranged in the central portion of the coil 2 is protruded greatly and is deeply embedded in the core 3 inside the coil 2. Further, the inner fins 51 around the inner fins 51 arranged in the central portion of the coil 2 also protrude longer than the other inner fins 51 and are embedded relatively deeply in the core 3 inside the coil 2. .
That is, an inner fin 51 having a large protruding amount is formed in the vicinity of the central axis of the coil 2, and the protruding amount of the inner fin 51 is gradually reduced from the central axis of the coil 2 toward the outside.
Further, the corrugated portion 53 of the lid portion 5 in this example is formed in a circular shape as in the second embodiment (see FIG. 3).
Others are the same as in the first embodiment.

In the case of this example, the amount of protrusion of the inner fin 51 can be increased as much as possible while preventing the formation of magnetic flux by the coil 2. Thereby, cooling efficiency can be improved, maintaining the magnetic characteristic of the reactor 1. FIG.
That is, as shown in FIG. 5, the magnetic flux M formed around the winding 21 of the coil 2, that is, the magnetic flux M formed in a loop shape continuously on the inner side and the outer side of the coil 2 is applied to the inner fin 51. It becomes difficult to be disturbed. Further, the heat radiation efficiency can be improved by forming the inner fins 51 in the vicinity of the central axis of the coil 2 that hardly affects the formation of the magnetic flux.
In addition, the same effects as those of the first embodiment are obtained.

Example 4
In this example, as shown in FIGS. 6 to 8, the lid 5 is provided with a radial slit portion 541 extending from the center toward the eight sides, and a line segment connecting the adjacent radial slit portions 541 and the end portions 543 thereof. This is an example in which an inner fin 51 and an outer fin 52 are formed by a triangular portion 58 formed by L1.
That is, at the line segment L1 connecting the ends of the adjacent radial slit portions 541, the metal plate constituting the lid portion 5 is bent toward the side opposite to the container portion 40 side, and the line segment L1 at the triangular portion 58 is folded. Further, it is bent toward the container portion 40 at a line segment L2 that is closer to the center than the line segment L1.

Thus, the inner fin 51 is configured by the central portion of the lid portion 5 in the triangular portion 58, and the outer fin 52 is configured by the portion near the line segment L <b> 2 in the triangular portion 58.
And as shown in FIG. 8, let the front-end | tip part of the inner side fin 51 be the state embedded in the core 3. As shown in FIG.

FIG. 6 is a plan view of a state after the radial slit portion 541 is provided on the metal plate constituting the lid portion 5 and before the bending process is performed. Moreover, the said radial slit part 541 can be formed by punching, for example.
Others are the same as in the first embodiment.
Also in this example, it has the same effect as Example 1.
Note that the number of the radial slit portions 541 in the formation direction from the center portion of the lid portion 5 is not particularly required to be eight, and may be the number in other directions.
Further, the line segment L1 may not be bent toward the side opposite to the container portion 40. In this case, the lid portion 5 in which the outer fins 52 are not formed is obtained.

(Example 5)
In this example, as shown in FIGS. 9 to 11, the lid 5 is provided with a radial slit 541 extending in the six directions from the center, and the outer periphery extends toward the end of the adjacent radial slit 541 at the end. This is an example in which a slit portion 542 is formed.
The inner fin 51 is formed by the triangular portion 58 formed by the radial slit portion 541, the outer peripheral slit portion 542, and the line segment L3 connecting the center portion of the lid portion 5 and the end portion of the outer peripheral slit portion 542. That is, at the line segment L3, the metal plate constituting the lid portion 5 is bent toward the container portion 40 side. Moreover, the radial slit part 541 and the outer periphery slit part 542 can be formed by punching, for example.
Others are the same as in the first embodiment.
Also in this example, it has the same effect as Example 1.
Note that the number of the radial slit portions 541 in the formation direction from the central portion of the lid portion 5 is not particularly required to be hexagonal, and may be the number in other directions.

(Example 6)
In this example, as shown in FIG. 12, the inner fin 51 is configured by a protruding portion that protrudes toward the container portion 40 toward the center side from the outer peripheral portion of the lid portion 5.
Moreover, the inner fin 51 by this protrusion part has a shape where the shape of a cross section parallel to the flat part 55 of the cover part 5 turns into a wave shape.
Others are the same as in the first embodiment.

In the case of this example, as in the third embodiment, the amount of protrusion of the inner fin 51 can be increased as much as possible while maintaining the magnetic characteristics of the reactor 1 while preventing the formation of magnetic flux by the coil 2. , Cooling efficiency can be improved.
In addition, the same effects as those of the first embodiment are obtained.

Sectional explanatory drawing of the reactor in Example 1. FIG. FIG. 3 is an explanatory plan view of a lid portion according to the first embodiment. Plane explanatory drawing of the cover part in Example 2. FIG. Sectional explanatory drawing of the reactor in Example 3. FIG. Sectional explanatory drawing of the reactor which shows the formation state of the magnetic flux in Example 3. FIG. Plane explanatory drawing of the cover part in Example 4 before a bending process. The perspective explanatory drawing of the cover part in Example 4. FIG. Sectional explanatory drawing of the reactor in Example 4. FIG. Plane explanatory drawing of the cover part in Example 5 before a bending process. FIG. 10 is a cross-sectional view taken along line AA in FIG. 9. FIG. 10 is a sectional view taken along line B-B in FIG. 9. The perspective explanatory drawing of the cover part in Example 6. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reactor 2 Coil 3 Core 4 Case 40 Container part 43 Opening part 5 Lid part 51 Inner fin 52 Outer fin

Claims (6)

A coil that generates magnetic flux when energized;
A core made of a magnetic powder mixed resin filled inside and outer periphery of the coil;
A case for accommodating the coil and the core inside;
The case includes a container portion having an opening and a lid portion that closes the opening of the container portion.
The lid portion has an inner fin protruding inside the case,
A reactor, wherein at least a part of the inner fin is embedded in the core.   The reactor according to claim 1, wherein the lid portion includes an outer fin that protrudes to the outside of the case.   The corrugated portion is provided in at least a part of the lid portion according to claim 2, and a peak portion and a trough portion of the corrugated portion constitute the outer fin and the inner fin, respectively. A reactor characterized by that.   The reactor according to claim 1, wherein the lid portion is provided with a slit portion that is partially opened.   The reactor according to any one of claims 1 to 4, wherein the core is partially disposed outside the lid portion.   6. The inner fin according to claim 1, wherein a plurality of the inner fins are formed, and the winding of the inner fins is more than the one formed at a position close to the winding constituting the coil. Reactor characterized in that the one formed farther away from the line projects larger.

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