JP5987847B2 - Reactor - Google Patents

Description

  The present invention relates to a reactor having an improved core structure.

  A reactor is a device for absorbing a rapid current fluctuation on an electric circuit, and is configured by arranging a coil outside a core (iron core). The core of the conventional reactor is constituted by joining a plurality of core members (components), and this joining part (butting part) functions as a gap. In order to avoid the magnetic flux saturation of the core, the gap is provided with a gap in a portion (magnetic path) through which the magnetic flux of the core passes. In order to design the reactor so as not to saturate the core in a wide current range, the insertion of the gap is important.

  From the viewpoint of suppressing the efficiency decrease due to leakage magnetic flux, the reactor gap is preferably provided in a plurality of locations rather than in one location, but the number of core members to be inevitably increased increases, There is also a problem that the joining process increases, which leads to product variations and cost increase. In addition, since a magnetic force is generated in the gap between the core members for the gap, an attractive force is generated between the core members, and the core vibrates (generation of a roaring sound).

  With respect to such a problem, in Patent Document 1, instead of providing a gap between core members (that is, the core members are directly joined and no gap is provided between the core members), the coil of the core member is not provided. A reactor has been proposed in which a through-hole is provided in a region to be mounted and this functions as a gap.

JP 2006-351920 A

  However, as a result of the study by the present inventors on the performance of the reactor shown in Patent Document 1, the reactor of Patent Document 1 has a low gap value because the gap effect cannot be sufficiently obtained, It turned out that it might become the level which cannot be used. It was also found that the initial inductance value tends to be abnormally high.

  Therefore, the object of the present invention is to solve the above-mentioned problems of the prior art, (i) the core can be configured with a small number of core members, and (ii) an appropriate gap effect can be obtained, so that it can be used in a wide current range. And (iii) providing a reactor that can obtain a normal initial inductance and (iv) can be manufactured at low cost.

The inventors of the present invention have studied the conditions for appropriately obtaining the gap effect for the reactor in which the core member is provided with the hole having the gap function, and as a result, have obtained the following knowledge.
(A) In the reactor of Patent Document 1, instead of providing a gap between the core members (that is, no gap is provided at the abutting portion between the core members), a hole having a gap function is provided in the core member. In order to obtain a normal initial inductance, it is necessary to provide a gap at the abutting portion between the core members. In addition, it is preferable to provide gaps at the abutting portions between the core members from the viewpoint of providing the gaps as dispersed as possible.

(B) When a hole having a gap function is formed in the core member, an appropriate gap effect is obtained, and in order to prevent the inductance value in the low current region from being lowered, the gap function is formed along the core member width direction. to form a hole (x _g) having, across the hole in the core member width direction (x _g) remained in not formed part (y) (i.e., holes in the core member longitudinal direction (x _g) core The total volume of the entire core of the connecting portion connecting the parts of the member) is the total volume of the gap (g) and the hole (x _g ) formed in the butt portion of the core members. It is necessary to make it below a predetermined ratio.

The present invention has been made on the basis of the above-described findings and has the following gist.
[1] A reactor including a core configured by abutting two or more core members and a coil attached to the core, wherein a gap (g) is configured at a butting portion between the core members, and at least one The core member of the portion has a hole (x _g ) having a gap function formed along the width direction of the portion (y) remaining without forming the hole (x _g ) in the core member width direction. Reactor characterized in that the total volume of the entire core is 0.5 to 10% of the total volume of the gap (g) and the hole (x _g ) formed in the butt portion of the core members. .

[2] The reactor according to [1], wherein the hole (x _g ) is a slit-like hole formed along the width direction of the core member.
[3] The reactor according to [1] or [2] includes a core configured by abutting a pair of core members, and each core member has one or more holes (x _g ). Characteristic reactor.
[3] In the reactor according to [1] or [2], a pair of cores having a substantially J-shaped planar shape by connecting the parallel short leg portions and the end portions of the long leg portions at the connection portions. A reactor comprising a core configured by abutting a short leg and a long leg with each other, and having one or more holes (x _g ) in the long leg of each core member .
In the present invention, the gap (g) refers to a void portion (including a void portion filled with a non-magnetic material) provided in the middle of the magnetic path of the core (portion through which the magnetic flux passes).

In the reactor of the present invention, since the hole (x _g ) formed in the core member has a gap function, the core can be configured with a small number of core members, and an appropriate gap effect can be obtained by the gaps provided in a dispersed manner. It can be used in a wide current range, and a normal initial inductance can be obtained. Moreover, since it is only necessary to form a hole (x _g ) having a gap function under a predetermined condition in the core member, it can be manufactured at a low cost.

The top view of the core in one embodiment of the present invention In Example 1, the top view of the core which comprises the reactor of an invention example and a comparative example In Example 1, the top view of the core which comprises the reactor of a prior art example In Example 1, the graph which shows the measurement result of the direct current superposition characteristic of a reactor In Example 2, the top view of the core which comprises the reactor of an invention example and a comparative example In Example 2, the top view of the core which comprises the reactor of a prior art example In Example 2, the graph which shows the measurement result of the direct current superposition characteristic of a reactor The top view which shows the other structural example of the core which comprises the reactor of this invention

The reactor of the present invention includes a core configured by abutting two or more core members, and a coil attached to the core, and forms a gap g at a butting portion between the core members, and at least a part of the cores The member has a hole _xg having a gap function formed along the width direction thereof. The core is configured by abutting two or more core members so that a magnetic path is formed.
FIG. 1 is a plan view showing a core 1 constituting a reactor in an embodiment of the present invention, and a coil 2 attached (exterior) to the core 1 is indicated by an imaginary line.

The shape and the number of cores and a plurality of core members (core parts) constituting the core are basically arbitrary, but the core 1 of the present embodiment is composed of a pair of core members 10a and 10b having the same shape. The Each of the core members 10a and 10b has a substantially J-shaped planar shape by connecting the end portions of the parallel short leg portion 101 and the long leg portion 102 with the connecting portion 100, and the short leg portions 101 of each other. The core 1 having a rectangular planar shape is configured by abutting the long leg portion 102 with each other. Then, the coil 2 is attached to both leg portions A composed of the short leg portion 101 and the long leg portion 102 which are abutted.
The core members 10a and 10b can be constituted by a laminated core (a steel plate obtained by punching and laminated and bonded in a block shape) or an iron powder core (a magnetic iron powder formed and hardened). In view of forming the hole _xg having a gap function, the laminated core is preferable.

A gap g is formed at each abutting portion between the core members 10a and 10b. As described above, in the reactors of Patent Documents 1 and 2, instead of providing a gap between the core members (that is, no gap is provided at the abutting portion between the core members), a hole having a gap function is provided in the core member. However, in order to obtain a normal initial inductance, it is necessary to provide a gap at the abutting portion between the core members. In addition, it is preferable to provide gaps at the abutting portions between the core members from the viewpoint of providing the gaps as dispersed as possible.
The initial inductance can be adjusted by the size of the gap g.
The gap g may be left as a gap, but is usually filled with a nonmagnetic material. This non-magnetic filler may be composed of, for example, a sheet-like member (ceramic, resin, paper, etc.) and an adhesive, or a resin filled with a core and copper wire insulating resin mold. May be.

In the present invention, at least a part of the core member 10 has the hole _xg having a gap function formed along the width direction. In the present embodiment, the long legs of the core members 10a and 10b are provided. There are holes _xg at two locations spaced apart in the longitudinal direction of the portion 102. The hole _xg having the gap function is provided along the core member width direction (the leg width direction of the core; hereinafter the same), and is provided in the form of a slit in the present embodiment. For example, it may be composed of two or more holes provided at intervals in the core member width direction. The hole _xg may be provided obliquely with respect to the core member width direction.
The gap g and the hole _xg are desirably provided so as to be located inside the coil 2.

In the present invention, the portion y remaining without the hole _xg being formed in the core member width direction, that is, the portion of the core member sandwiching the hole _xg in the core member longitudinal direction (core leg longitudinal direction; hereinafter the same) The volume of the “connecting portion that connects the two” is restricted to a specific condition. Each hole _xg has two or more portions y, but each hole _xg of this embodiment has portions y on both sides thereof. In order to help understanding, one portion y is shown by broken line hatching in the partially enlarged view of FIG.
In addition, when the hole _xg is provided obliquely with respect to the core member width direction, the core portion on the extension in the formation direction of the hole _xg is defined as a portion y.

In the present invention, the total volume Y of the entire core of the portion y, the total volume G of the entire core of the core member 10a, 10b if and butt portion constituted gap g and pore x _g 0.5 to 10 %. In the present embodiment, the core members 10a and 10b each have two holes _xg, and the entire core has two gaps g, and the total volume of these holes _xg and gaps g is a total volume G. is there. On the other hand, in each core member 10a, 10b, there are portions y on both sides in the core member width direction of each hole _xg , and there are eight portions y in the entire core. The total volume of these eight portions y is the total volume Y.

If the total volume Y of the portion y exceeds 10% of the total volume G of the gap g and pore x _g, no sufficient gaps effect is obtained due to pores x _g, it is impossible to avoid core saturation as a reactor. As a result, the inductance value in the low current region may decrease and become unusable. On the other hand, when the total volume Y of the portion y is less than 0.5% of the total volume G of the gap g and the hole _xg , a processing that leaves the portion y in forming the hole _xg (for example, punching of a steel plate) Even if it can be processed, it may be damaged in the manufacturing process due to insufficient strength of the portion y.

Usually, the hole _xg is a through-hole, but not a through-hole, but a part (any one of the upper end, the lower end, and the middle of the hole) may have a non-through portion. However, the presence of two or more non-penetrating portions is not preferable because a residual space is generated when resin molding or the like is performed on the core in a subsequent process.
Width w _y part y of the core member width direction, from the viewpoint of effective utilization of the gap characteristics, it is preferable as small as possible to the extent that part y is not damaged. Specifically, the width of the portion y w _y is preferably 20% or less of the core member width w (the leg width of the core). Moreover, when the core members 10a and 10b are laminated cores, the width w _{y of the} portion y is preferably equal to or greater than the thickness of the material steel plate from the viewpoint of workability.
The length l _x of the hole _{xg in} the longitudinal direction of the core member is preferably larger than the width w _{y of the} portion y from the viewpoint of effectively utilizing the gap characteristics.
Usually, when the resin for insulation of the core 1 and the coil 2 is press-fitted into the hole _xg , the resin is filled.

The core structure of the present invention can be applied to various types of cores other than the embodiment of FIG. 8A to 8C show examples of applicable core forms, but the present invention is not limited to these.
Further, the so-called 6.5% high silicon steel sheet is a material having high magnetic permeability, and since the gap effect cannot be sufficiently obtained, the problem of the present invention that the inductance value in the low current region is lowered is such a high silicon steel sheet. This is particularly problematic in a laminated core made of steel plates. Therefore, the present invention exhibits a particularly great effect when the core member is a laminated core of a high silicon steel sheet in which the silicon concentration of the steel sheet surface layer is 6.0 mass% or more.

[Example 1]
The reactors of Invention Examples 1 to 4 and Comparative Examples 1 and 2 in which a core having the planar shape and dimensions shown in FIG. 2 is formed by punching and stacking a high silicon steel plate (6.5% Si). Were manufactured, and their DC superposition characteristics were measured. Similarly, a conventional reactor in which a core having the planar shape and dimensions shown in FIG. 3 is formed by punching and stacking a high silicon steel plate (6.5% Si) and forming a core having the planar shape and dimensions shown in FIG. The superposition characteristics were measured. The reactor was configured with a core cross-sectional area of 400 mm ² , a coil φ of 2.9 mm, and a coil winding of 60 turns.
Tables 1 and 2 show the configuration of the core of each reactor and the presence or absence of breakage of the core in the manufacturing process, and FIG. 4 shows the measurement results of the DC superposition characteristics. In addition, AE of Table 2 is the dimension AE of each part of a core shown in FIG.2 and FIG.3.

In Comparative Example 1, the portion y was damaged during production due to insufficient strength of the portion y, and could not be produced. Further, in Comparative Example 2, since the total volume of the portion y is too large, the gap effect is reduced, the inductance value in the low current region is lowered, and the level cannot be used. On the other hand, the inventive examples 1 to 4 do not decrease the inductance value in a low current region, and have good characteristics, and the conventional example 1 in which the core is composed of four core members (no holes x _g) The same level of direct current superposition characteristics as

As another comparative example, a reactor in which a gap g was not provided in the planar shape shown in FIG. 2 was manufactured using two core members obtained by punching and stacking a high silicon steel plate (6.5% Si). That is, this comparative example has a hole _xg that satisfies the present invention conditions, but does not have a gap g. The reactor configuration was such that the dimensions of each core part in FIG. 2 were A: 2.1 mm, B: 0.1 mm, C: 0 mm, core cross-sectional area 400 mm ² , coil φ2.9 mm, and coil winding 60 turns. As a result of measuring the DC superposition characteristics of this reactor, the initial inductance value was five times or more compared with the inductance value of the stationary part, and the characteristics that were difficult to use as a reactor were shown.

[Example 2]
Production of reactors of Invention Examples 5 and 6 and Comparative Example 3 in which a core having a planar shape and dimensions shown in FIG. 5 is formed by punching and stacking a high silicon steel plate (6.5% Si). Then, their DC superposition characteristics were measured. Similarly, a conventional reactor in which a core having the planar shape and dimensions shown in FIG. 6 is formed by punching and stacking a high silicon steel plate (6.5% Si) and forming a core having the planar shape and dimensions shown in FIG. The superposition characteristics were measured. The configuration of the reactor was a core cross-sectional area of 450 mm ² , a coil φ of 2.9 mm, and a coil winding of 60 turns.
Tables 3 and 4 show the configuration of the core of each reactor and the presence or absence of damage to the core in the manufacturing process, and FIG. 7 shows the measurement results of the DC superposition characteristics. In addition, AE of Table 4 is the dimension AE of each part of a core shown in FIG.5 and FIG.6.

In Comparative Example 3, since the total volume of the portion y is too large, the gap effect is reduced, the inductance value in the low current region is lowered, and the level cannot be used. On the other hand, Invention Examples 5 and 6 do not decrease the inductance value in a low current region, provide good characteristics, and Conventional Example 2 in which the core is composed of four core members (no holes x _g) . The same level of direct current superposition characteristics as

DESCRIPTION OF SYMBOLS 1 Core 2 Coil 10,10a, 10b Core member 100 Connection part 101 Short leg part 102 Long leg part
g gap
x _g hole
y part A leg

Claims (4)

A reactor including a core configured by abutting two or more core members, and a coil attached to the core,
The gap (g) is formed at the abutting portion between the core members, and at least a part of the core member has a hole (x _g ) having a gap function formed along the width direction thereof,
The total volume of the entire core of the portion (y) remaining without forming the hole (x _g ) in the width direction of the core member is the gap (g) and hole (x _g ) formed in the butt portion of the core members A reactor characterized by being 0.5 to 10% of the total volume of the entire core. The reactor according to claim 1, wherein the hole (x _g ) is a slit-like hole formed along the width direction of the core member. The reactor according to claim 1 or 2, comprising a core configured by abutting a pair of core members, wherein each core member has one or more holes (x _g ). A pair of core members having a substantially J-shaped planar shape are brought into contact with each other with the short leg portion and the long leg portion of each other by connecting the ends of the parallel short leg portion and the long leg portion at the connecting portion. The reactor according to claim 1, wherein the core member includes one or more holes (x _g ) in a long leg portion of each core member.

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