JP2010245154A - Reactor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reactor and a method for manufacturing the same which can precisely secure the ease of manufacturing and desired inductance. <P>SOLUTION: The reactor 1 has: a coil unit 6 provided with a coil 2 which generates magnetic flux by energization, and also has a straight part 21 in which a shape viewed from a winding axis direction is linear, and a plurality of legs 5 arranged partially at a bottom which is one end in the winding axis direction in the coil 2; a core 3 formed of a magnetic powder mixing resin which is filled in the surrounding the coil unit 6; and a case 4 for containing the coil 2 and the core 3 inside. The coil unit 6 is integrally provided with at least one of the plurality of legs 5 at a bottom of the straight part 21 in the coil 2. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a reactor having a core made of a magnetic powder mixed resin and a manufacturing method thereof.

Conventionally, there is a reactor in which a magnetic powder mixed resin made of a resin mixed with magnetic powder is filled around a coil as a core. In manufacturing such a reactor, a pedestal is disposed at the bottom of the case, and a coil is placed on the pedestal, and then a liquid magnetic powder mixed resin is injected. Then, a reactor is obtained by hardening this magnetic powder mixed resin (refer patent document 1).
Thus, the reason for using the pedestal is to secure a space filled with the magnetic powder mixed resin for forming the magnetic path between the bottom surface of the coil and the bottom portion of the case.

JP 2008-218724 A

However, disposing the pedestal under the coil as described above increases the number of parts, increasing the number of manufacturing steps and increasing the cost.
Also, when another base is placed on the bottom of the case, the coil is placed thereon, and the magnetic powder mixed resin is filled around the coil in the case, the base becomes unstable, and the coil with respect to the case There is a risk of displacement. As a result, there is a possibility that sufficient inductance of the reactor cannot be obtained.
In addition, depending on the installation position of the pedestal, the pedestal interferes with the magnetic path formed by the coil, so that the inductance may be reduced, and it may be difficult to obtain a desired inductance.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a reactor that can be easily manufactured and can ensure a desired inductance with high accuracy, and a method for manufacturing the reactor.

In the first invention, a magnetic flux is generated by energization, and a coil having a linear portion whose shape when viewed from the winding axis direction is linear, and a bottom portion which is one end in the winding axis direction of the coil are partially arranged. A coil unit having a plurality of legs provided;
A core made of a magnetic powder mixed resin filled around the coil unit;
A case for accommodating the coil and the core inside;
The coil unit may be a reactor in which at least one of the plurality of leg portions is integrally provided on a bottom portion of the linear portion of the coil (claim 1).

According to a second aspect of the present invention, a magnetic flux is generated by energization and a linear portion having a linear shape when viewed from the winding axis direction is partially disposed on a bottom portion of the coil that is one end in the winding axis direction. A coil placement step of placing a coil unit including a plurality of legs provided inside the case;
A resin filling step of filling a liquid magnetic powder mixed resin on the inside and outer periphery of the coil in the case;
A resin curing step in which the magnetic powder mixed resin is cured to form a core,
The coil unit includes a reactor manufacturing method in which at least one of the plurality of leg portions is integrally provided on a bottom portion of the linear portion of the coil (Claim 8).

  In the first invention, the coil unit has the plurality of legs integrally provided at the bottom. Therefore, when manufacturing the reactor, it is not necessary to place a coil by placing a pedestal of another member on the bottom surface of the case, and the coil unit may be placed in the case as it is. Therefore, the number of parts can be reduced, and the number of manufacturing steps can be reduced. As a result, a low-cost reactor that is easy to manufacture can be obtained.

  Moreover, since the said leg part is integrated with the coil unit, at the time of manufacture of a reactor, a coil unit does not shift easily in a case. Therefore, the coil can be arranged at an accurate position in the case, and the inductance of the reactor can be accurately maintained at a desired value.

  Moreover, since the said leg part is arrange | positioned at the bottom part of the linear part in a coil, obstruction of the magnetic path by this leg part can be suppressed. That is, the magnetic flux formed by the coil concentrates on the other curved portion than the straight portion. Therefore, if leg portions are formed in the curved portion, many magnetic paths are inhibited accordingly. In other words, the magnetic path to be obstructed can be reduced in the case where the leg portion having the same size is arranged in the straight line portion than in the case where the leg portion having the same size is arranged in the curved portion. As a result, a decrease in the inductance of the reactor can be suppressed, and a desired inductance can be ensured with high accuracy.

  As described above, according to the present invention, it is possible to provide a reactor that can be easily manufactured and can ensure a desired inductance with high accuracy.

Also in the second invention, as in the first invention, the above-described effects can be obtained by using the coil unit having the above-described configuration and having the legs integrally provided.
Therefore, according to the present invention, it is possible to provide a method for manufacturing a reactor that is easy to manufacture and can ensure a desired inductance with high accuracy.

Sectional explanatory drawing of the reactor by the plane orthogonal to the winding axis direction in Example 1. FIG. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. FIG. 3 is a cross-sectional view taken along line B-B in FIG. 1. The perspective view of the coil in Example 1. FIG. The perspective view of the coil unit in Example 1. FIG. The perspective view of the reactor in Example 1. FIG. FIG. 3 is an explanatory diagram illustrating a magnetic flux formation state in the first embodiment. Sectional explanatory drawing of the reactor by a plane which passes along a leg part in Example 2 and is parallel to a winding-axis direction. Sectional explanatory drawing of the reactor by the plane parallel to the winding-axis direction which does not pass a leg part in Example 2. FIG.

In the present invention, as the magnetic powder mixed resin, for example, a resin obtained by mixing a magnetic powder such as iron powder in a thermosetting resin such as an epoxy resin or a resin such as a thermoplastic resin can be used.
In the present invention, the winding axis direction of the coil on the side opposite to the side on which the leg portion is provided is described as “upper”. In other words, the posture may change depending on the usage situation of the reactor, but unless otherwise specified, the side where the leg portion is disposed is the lower side and the opposite side is the upper side with respect to the coil. To do.

Further, it is preferable that all of the plurality of leg portions are provided at the bottom of the straight portion of the coil (claims 2 and 9).
In this case, obstruction of the magnetic path by the legs can be reduced as much as possible to suppress a decrease in the inductance of the reactor, and a highly accurate inductance can be maintained.

Preferably, the coil unit has an insulating coat for covering the coil, and the leg portion is integrally formed with the insulating coat (claims 3 and 10).
In this case, when the insulating coat is formed on the coil, the legs can be formed at the same time. Therefore, the legs can be formed without increasing the number of manufacturing steps. Therefore, a reactor excellent in production efficiency and a manufacturing method thereof can be obtained.

Preferably, the coil unit has a bobbin around which the coil is wound, and the leg portion is integrally formed with the bobbin (claims 4 and 11).
In this case, when manufacturing the bobbin, the legs can be formed at the same time. Therefore, the legs can be formed without increasing the number of manufacturing steps. Therefore, a reactor excellent in production efficiency and a manufacturing method thereof can be obtained.

Further, the height of the leg portion may be equal to the height of the core of the portion disposed immediately above the insulating coat covering the end of the coil opposite to the side where the leg portion is provided. Preferred (claims 5 and 12).
In this case, since the core heights above and below the coil can be made equal, the magnetic paths above and below the coil can be ensured equally. Therefore, the magnetic path can be efficiently formed in the core, and the inductance of the reactor can be improved.

Further, when D is the sum of the thicknesses of all the legs in the winding direction of the coil and E is the sum of the lengths of the straight portions of the coil, it is preferable that D ≧ E / 5 is satisfied ( Claims 6 and 13).
In this case, inhibition of the magnetic path by the legs can be sufficiently suppressed.
In the case of D <E / 5, the influence of obstruction of the magnetic path by the leg portion is increased, and it may be difficult to obtain a desired inductance.

Moreover, it is preferable that the width | variety of the said leg part in the direction orthogonal to the winding direction of the said coil is below the width | variety which combined the said coil and the said insulation coat in the direction orthogonal to the winding direction of the said coil (claim). Item 7, 14).
In this case, inhibition of the magnetic path by the legs can be sufficiently suppressed.

Example 1
A reactor according to an embodiment of the present invention and a manufacturing method thereof will be described with reference to FIGS.
The reactor 1 of this example includes a coil unit 6 including a coil 2 that generates a magnetic flux when energized, a core 3 made of a magnetic powder mixed resin filled around the coil unit 6, and the coil 2 and the core 3 inside. And a case 4 for housing.

As shown in FIG. 1, the coil 2 includes a linear portion 21 having a linear shape as viewed from the winding axis direction and a curved portion 22 having a curved shape. Further, as shown in FIGS. 2 and 5, a plurality of legs 5 are partially disposed on the bottom 24 which is one end of the coil 2 in the winding axis direction.
The coil unit 6 is formed by integrally providing at least one of the plurality of leg portions 5 on the bottom 24 of the linear portion 21 in the coil 2.

As shown in FIG. 1, the coil 2 includes four straight portions 21 and four curved portions 22. Adjacent straight portions 21 are arranged at right angles to each other, and a curved portion 22 is formed between the adjacent straight portions 21.
One leg portion 5 is fixed to each bottom portion 24 of each linear portion 21. The leg portion 5 is formed at the center position of each linear portion 21. That is, all of the plurality of leg portions 5 are provided on the bottom portion 24 of the linear portion 21 in the coil 2.

As the magnetic powder mixed resin constituting the core 3, for example, a resin obtained by mixing magnetic powder such as iron powder in a resin such as a thermosetting resin such as an epoxy resin or a thermoplastic resin can be used.
The case 4 can be made of, for example, aluminum or an alloy thereof. As shown in FIG. 2, the case 4 is provided with an axial core portion 41 made of the same material as that of the case 4 erected from the bottom surface portion 42, and the axial core portion 41 is disposed inside the coil 2.

As shown in FIG. 4, the coil 2 is formed by spirally winding a rectangular conductor wire having a substantially rectangular cross section.
As shown in FIGS. 2, 3, and 6, the coil unit 6 includes an insulating coat 61 that covers the coil 2, and the leg portion 5 is integrally formed with the insulating coat 61. The insulating coat 61 can be made of, for example, a resin such as epoxy, urethane, or silicone. And the leg part 5 can also be comprised with these resin same as the insulating coat 61. FIG.

As shown in FIG. 2, the height H <b> 1 of the leg portion 5 is the portion of the core 3 disposed immediately above the insulating coat 61 that covers the upper portion of the coil 2 (the end portion opposite to the side where the leg portion 5 is provided). Is equivalent to the height H2.
As shown in FIG. 1, when the sum of the thicknesses d of all the legs 5 in the winding direction of the coil 2 is D and the sum of the lengths e1 and e2 of the straight portions 21 of the coil 2 is E, D ≧ E / 5 is satisfied.

  Further, as shown in FIG. 2, the width W of the leg portion 5 in the direction orthogonal to the winding direction of the coil 2 is the combined width V of the coil 2 and the insulating coat 6 in the direction orthogonal to the winding direction of the coil 2. It is as follows. In this example, the width W is substantially equal to the width V.

In manufacturing the reactor 1 of this example, the following coil arrangement | positioning process, the resin filling process, and the resin hardening process are performed.
In the coil placement step, the coil unit 6 including the coil 2 and the plurality of legs 5 is placed inside the case 4. As shown in FIGS. 2 and 5, the coil unit 6 is formed by integrally providing a plurality of legs 5 on the bottom 24 of the linear portion 21 in the coil 2.
In the resin filling step, liquid magnetic powder mixed resin is filled into the inside and the outer periphery of the coil 2 in the case 4.
In the resin curing step, the magnetic powder mixed resin is cured to form the core 3.
By the above, the reactor 1 shown in FIGS. 1-3, FIG. 6 is obtained.

In addition, the coil unit 6 is provided with an insulating coat 61 on the surface of the coil 2 as shown in FIG. 4, and a part of the insulating coat 61 is a leg portion 5 (FIG. 5). In applying the insulating coating 61 to the coil 2, for example, a molding die can be used. In this case, a cavity for molding the leg 5 is provided in the mold. And the coil 2 is arrange | positioned in this shaping | molding die, a liquid insulation coating material is cast, and then the insulation coating material is hardened and demolded. As a result, as shown in FIG. 1 to FIG. 3 and FIG. 5, the insulating coat 61 is formed on the surface of the coil 2, and the legs 5 integrally formed with the insulating coat 61 are formed, whereby the coil unit 6 is obtained. It is done.
In addition, the insulating coat 61 is not applied to the pair of terminals 23 in the coil 2.
In addition, the reactor 1 of this example can be assembled and used for the power converter device used for an electric vehicle, a hybrid vehicle, etc., for example.

Next, the function and effect of this example will be described.
In the reactor 1 of this example, the coil unit 6 is formed by integrally providing a plurality of legs 5 on the bottom 24. Therefore, when manufacturing the reactor 1, it is not necessary to place the pedestal of another member on the bottom surface portion 42 of the case 4 to place the coil 2, and the coil unit 6 may be placed in the case 4 as it is. Therefore, the number of parts can be reduced, and the number of manufacturing steps can be reduced. As a result, a low-cost reactor 1 that can be easily manufactured can be obtained.

  Further, since the leg portion 5 is integrated with the coil unit 6, the coil unit 6 is not easily displaced in the case 4 when the reactor 1 is manufactured. Therefore, the coil 2 can be arranged at an accurate position in the case 4 and the inductance of the reactor 1 can be accurately maintained.

  Moreover, since the leg part 5 is arrange | positioned in the bottom part 24 of the linear part 21 in the coil 2, inhibition of the magnetic path by this leg part 5 can be suppressed. That is, as shown in FIG. 7, the magnetic flux φ formed by the coil 2 is concentrated on the other curved portion 22 (particularly the inside) than the straight portion 21. Therefore, if the leg part 5 is formed in the curved part 22, many magnetic paths will be inhibited. In other words, the magnetic path to be obstructed can be reduced in the case where the leg part 5 having the same size is arranged in the straight part 21 than in the case where the leg part 5 is arranged in the curved part 22. As a result, a decrease in the inductance of the reactor 1 can be suppressed, and a desired inductance can be ensured with high accuracy.

Further, since the plurality of legs 5 are all provided at the bottom 24 of the linear portion 21 in the coil 2, the magnetic path obstruction by the legs 5 can be reduced as much as possible, and the inductance of the reactor 1 can be maintained with high accuracy. it can.
The coil unit 6 has an insulating coat 61 that covers the coil 2, and the leg portion 5 is integrally formed with the insulating coat 5. Therefore, when the insulating coat 61 is formed on the coil 2, the legs 5 can be formed at the same time. Therefore, the legs 5 can be formed without increasing the number of manufacturing steps. Therefore, the reactor 1 excellent in production efficiency and its manufacturing method can be obtained.

  Further, the height H1 of the leg portion 5 is equal to the height H2 of the core 3 at the portion disposed immediately above the insulating coat 61 covering the end portion of the coil 2 opposite to the side where the leg portion 5 is provided. is there. Therefore, as shown in FIG. 3, the height H3 (= H1 = H2) of the core 3 above and below the coil 2 can be made equal, so that the magnetic paths above and below the coil 2 can be ensured equally. Therefore, the magnetic path can be efficiently formed in the core 3 and the inductance of the reactor 1 can be improved.

Further, when D is the sum of the thicknesses d of all the legs 5 in the winding direction of the coil 2 and E is the sum of the lengths e1 and e2 of the linear portions 21 of the coil 2, D ≧ E / 5 is satisfied. . Therefore, the inhibition of the magnetic path by the leg 5 can be sufficiently suppressed.
Further, since the width W of the leg portion 5 is equal to or smaller than the combined width V of the coil 2 and the insulating coat 61 (equivalent in the present example), the inhibition of the magnetic path by the leg portion 6 can be sufficiently suppressed. .

  As described above, according to this example, it is possible to provide a reactor that can be easily manufactured and can ensure a desired inductance with high accuracy, and a manufacturing method thereof.

(Example 2)
In this example, as shown in FIGS. 8 and 9, the coil unit 6 has a bobbin 62 around which the coil 2 is wound, and the leg portion 5 is an example of the reactor 1 formed integrally with the bobbin 62. .
The bobbin 62 includes a cylindrical portion 621 and flanges 622 and 623 that protrude outward at the upper end and the lower end of the cylindrical portion 621, respectively. The coil 2 is disposed in a holding space 624 formed between the pair of flange portions 622 and 623 on the outer periphery of the cylindrical portion 621. An insulating coat 61 is formed so as to cover the coil 2 disposed in the holding space 624 and to fill the gap between the coil 2 and the bobbin 62.

And the leg part 5 is integrally molded by the lower surface of the collar part 623 below.
The bobbin 62 including the leg 5 can be made of a resin such as PPS (polyphenylene sulfide).
Others are the same as in the first embodiment.

In the case of this example, when the bobbin 62 is manufactured, the legs 5 can be formed at the same time. Therefore, the legs 5 can be formed without increasing the number of manufacturing steps. Therefore, a reactor excellent in production efficiency and a manufacturing method thereof can be obtained.
In addition, the same effects as those of the first embodiment are obtained.

1 Reactor 2 Coil 21 Straight Line 3 Core 4 Case 5 Leg 6 Coil Unit

Claims (14)

A coil that generates a magnetic flux when energized and has a linear portion that is straight when viewed from the winding axis direction, and a plurality of legs that are partially disposed on the bottom of the coil that is one end in the winding axis direction A coil unit comprising a portion,
A core made of a magnetic powder mixed resin filled around the coil unit;
A case for accommodating the coil and the core inside;
The reactor is characterized in that at least one of the plurality of leg portions is integrally provided on a bottom portion of the linear portion of the coil.   2. The reactor according to claim 1, wherein all of the plurality of leg portions are provided at a bottom portion of the linear portion of the coil.   3. The reactor according to claim 1, wherein the coil unit includes an insulating coat that covers the coil, and the leg portion is integrally formed with the insulating coat.   The reactor according to any one of claims 1 to 3, wherein the coil unit includes a bobbin around which the coil is wound, and the leg portion is integrally formed with the bobbin.   5. The height of the leg according to claim 3 or 4, wherein the height of the core is a height of a portion of the coil disposed immediately above the insulating coat covering an end of the coil opposite to the side where the leg is provided. Reactor characterized by equality.   In any one of Claims 3-5, when the sum total of the thickness of all the said leg parts in the winding direction of the said coil is set to D, and the sum total of the length of the said linear part of the said coil is set to D, Reactor characterized by satisfying ≧ E / 5.   The width of the leg in the direction orthogonal to the winding direction of the coil according to any one of claims 3 to 6, wherein the coil and the insulating coat in the direction orthogonal to the winding direction of the coil are combined. Reactor characterized by being less than the width. A coil that generates a magnetic flux when energized and has a linear portion that is straight when viewed from the winding axis direction, and a plurality of legs that are partially disposed on the bottom of the coil that is one end in the winding axis direction A coil placement step of placing a coil unit comprising a portion inside the case;
A resin filling step of filling a liquid magnetic powder mixed resin on the inside and outer periphery of the coil in the case;
A resin curing step in which the magnetic powder mixed resin is cured to form a core,
The coil unit is formed by integrally providing at least one of the plurality of leg portions on a bottom portion of the linear portion of the coil.   9. The method of manufacturing a reactor according to claim 8, wherein all of the plurality of leg portions are provided at a bottom portion of the linear portion of the coil.   10. The method of manufacturing a reactor according to claim 8, wherein the coil unit includes an insulating coat that covers the coil, and the leg portion is integrally formed with the insulating coat.   11. The reactor according to claim 8, wherein the coil unit has a bobbin around which the coil is wound, and the leg portion is integrally formed with the bobbin. Method.   In Claim 10 or 11, the height of the said leg part is the height of the said core of the part arrange | positioned just above the said insulation coat which covers the edge part on the opposite side to the side which provided the said leg part in the said coil. A reactor manufacturing method characterized by being equivalent.   In any one of Claims 10-12, when the sum total of the thickness of all the said leg parts in the winding direction of the said coil is set to D, and the sum total of the length of the said linear part of the said coil is set to D, The manufacturing method of the reactor characterized by satisfy | filling> = E / 5.   The width of the leg portion in a direction orthogonal to the winding direction of the coil according to any one of claims 10 to 13, wherein the coil and the insulating coat in a direction orthogonal to the winding direction of the coil are combined. The reactor manufacturing method characterized by being below the width.

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