JP2015138911A - Reactor core - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reactor core which makes possible to ease the reduction in inductance in a current region over a rating current in a reactor with a silicon steel plate laminated core.SOLUTION: A reactor core comprises: a laminated core 1 formed by laminating silicon steel plates each having a thickness of 0.35 mm or less and a Si concentration within a range of 3.0-7.0 mass%; a dust core layer 2a provided in a center portion in a direction of lamination of the laminated core; and a dust core layer 2b provided at one or more than one point in a plane perpendicular to a direction of magnetization of the laminated core. Thus, it becomes possible to ease the reduction in inductance in a current region over a rating current in a reactor with a silicon steel plate laminated core.

Description

  The present invention relates to a reactor reactor used in a power supply circuit for driving a high-output electric motor of a hybrid vehicle.

  A reactor, which is an important component of power electronics used in power supply devices in various fields such as the energy field, automobile field, and home appliance field, is composed of a core (magnetic core) and a coil formed of a magnetic material. In general, this reactor employs a structure having a gap between cores in a magnetic path in order to suppress magnetic saturation and ensure inductance when DC current is superimposed. In particular, when using a laminated core or a wound core formed of a silicon steel plate having a high magnetic permeability, a gap between the cores is essential. On the other hand, when using a core made of magnetic material particles and non-magnetic material interparticle substances such as a dust core, the non-magnetic material may act as a gap. The gap between is not required.

  One of the important characteristics of the reactor is the DC superposition characteristic. The DC superimposition characteristic is a characteristic that represents the relationship between the inductance and the current, and is a characteristic that is necessary for obtaining a predetermined inductance at a predetermined current. Inductance drops sharply when a certain current value is exceeded, but a current value slightly lower than the current value at which this sudden inductance drop occurs is determined as the rated current in the use conditions. This DC superimposition characteristic varies depending on the number of turns of the coil, the core material, the gap condition, and the like. The number of coil turns, the core material, the gap condition, and the like also affect the core loss and copper loss.

  Various techniques have been disclosed for the core material and gap conditions. For example, Patent Document 1 discloses a reactor including a composite core composed of a high permeability magnetic core (winding) and a powder magnetic core, and a plurality of gaps. Patent Document 2 discloses a reactor comprising a composite core of a ferrite core and a dust core. Patent Document 3 discloses a reactor using a dust core. Patent Document 4 discloses a reactor including a laminated core and a plurality of gaps.

Japanese Patent No. 4895171 JP 2007-128951 A JP 2008-192897 A JP 2008-235525 A

  However, in any of the techniques described in Patent Documents 1 to 4, the core and the gap made of the same or different materials are arranged in series on the magnetic circuit. Therefore, due to the direct current superimposition characteristics, there is a problem in that a core made of a material having a high permeability causes a magnetic saturation, and thus a sudden decrease in inductance occurs.

  Usually, a current value slightly smaller than a current value at which the inductance is rapidly decreased is determined as the rated current at the upper limit of the reactor usage conditions. Here, the higher the magnetic permeability of the core material, the lower the rated current and the larger the current region where the inductance is reduced. Therefore, in order to increase the rated current or to mitigate the decrease in inductance in the current region exceeding the rated current, use a core material with a low permeability and then increase the magnetic path cross-sectional area of the core. Either the number of gaps should be increased to increase the total gap length, or one of the measures must be taken. However, if the cross-sectional area of the magnetic path is increased, the physique of the reactor is increased, which makes it difficult to mount on the device. In addition, increasing the number of gaps in a series magnetic circuit makes it difficult to maintain the core and accurately adjust the gap.

  The present invention has been made in view of the above, and an object of the present invention is to provide a reactor that can alleviate a decrease in inductance in a current region exceeding a rated current in a reactor using a silicon steel sheet laminated core. And

  In the reactor using the silicon steel sheet laminated core, the present inventors have devised and studied the combined use of the dust core (dust core) and the silicon steel sheet laminated core. As a result, the above-described problems were solved and the object was achieved by producing and using a reactor core having the following configuration.

  The reactor core according to the present invention includes a laminated core formed by laminating silicon steel sheets having a thickness of 0.35 mm or less and a Si concentration in a range of 3.0 to 7.0% by mass, A first dust core layer provided at a central portion in the stacking direction of the stacked core, and a second dust core layer provided at one or a plurality of positions on a plane perpendicular to the magnetization direction of the stacked core. .

  Moreover, the reactor according to the present invention is characterized in that, in the above invention, the first dust core layer and the second dust core layer are integrated or connected.

  Further, in the reactor according to the present invention, the multiplication value of the permeability and thickness of the first dust core layer is 1/10 or more of the multiplication value of the permeability of the silicon steel sheet and the total thickness in the stacking direction. The total thickness in the magnetization direction of the second dust core layer is in the range of 1/100 or more and 1/3 or less of the length in the longitudinal direction.

  The reactor according to the present invention is characterized in that, in the above invention, when the magnetization direction is the longitudinal direction, both end surfaces in the longitudinal direction are the second dust core layers.

  In the reactor according to the present invention, in the above invention, when the magnetization direction is the longitudinal direction, the surface provided at one or a plurality of locations dividing the longitudinal direction is the second dust core layer. It is characterized by.

  In the reactor according to the present invention, when the magnetization direction is the longitudinal direction, the both ends of the longitudinal direction and the surface provided at one place or a plurality of places dividing the longitudinal direction are the second dust core. It is characterized by being layered.

  The reactor according to the present invention is characterized in that, in the above invention, when the magnetization direction passes through a plane parallel to the longitudinal direction, the second dust core layer is formed on the plane.

  In the reactor according to the present invention, in the above invention, the Si concentration of the surface layer of the laminated core is higher than the Si concentration of the center layer, and the magnetic permeability of the first dust core layer and the second dust core layer is determined by the silicon steel plate. It is characterized by being lower than the magnetic permeability.

  According to the present invention, in a reactor using a silicon steel sheet laminated core, it is possible to mitigate a decrease in inductance in a current region exceeding the rated current.

FIG. 1 is a schematic diagram showing a basic configuration of a reactor core according to an embodiment of the present invention. FIG. 2 is a schematic view illustrating the basic configuration of the reactor core according to the present embodiment. FIG. 3 is a schematic view illustrating the basic configuration of the reactor core of the present embodiment. FIG. 4 is a schematic view illustrating the basic configuration of the yoke portion of the reactor core according to this embodiment. FIG. 5 is a schematic view illustrating a schematic configuration of a reactor using the reactor core of the present embodiment. FIG. 6 is a diagram for explaining a magnetic path of a reactor using the reactor core of the present embodiment. FIG. 7 is a diagram for explaining the DC superimposition characteristics of the reactor using the reactor core of the present embodiment. FIG. 8 is a diagram for explaining a magnetic path of a reactor using the reactor core of the present embodiment. FIG. 9 is a diagram for explaining the DC superimposition characteristics of the reactor using the reactor core according to the present embodiment. FIG. 10 is a schematic view illustrating a schematic configuration of a reactor using the reactor core of the present embodiment. FIG. 11 is a schematic view illustrating a schematic configuration of a reactor using a reactor core of a comparative example. FIG. 12 is a diagram for explaining the DC superimposition characteristics of a reactor using the reactor core of the comparative example. FIG. 13 is a diagram illustrating a relationship between a reactor current and an inductance using the reactor core according to the embodiment. FIG. 14 is a diagram illustrating a relationship between a reactor current and inductance using the reactor core according to the embodiment.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. Moreover, in description of drawing, the same code | symbol is attached | subjected and shown to the same part.

  A reactor core according to an embodiment of the present invention includes two leg portions and two yoke portions arranged so as to connect the two leg portions at both ends, and is generally configured in a ring shape. And a coil is wound around each leg part, and the reactor for acquiring electrical characteristics, such as predetermined inductance, is constituted.

[Basic core of Reactor]
First, a basic configuration core that is a structural unit of a reactor core according to the present embodiment will be described. The basic constituent core of the reactor core according to the present embodiment is a rectangular parallelepiped composite integrated core composed of a laminated core 1 and a dust core layer 2 as illustrated in FIG. The laminated core 1 is formed by laminating silicon steel plates having a plate thickness of 0.35 mm or less and a Si concentration within a range of 3.0 to 7.0 mass%. When the reactor core is arranged so that the magnetization direction 3 of the laminated core 1 is in the direction shown in FIG. 1, the basic configuration core includes a central portion in the lamination direction of the laminated core 1 and a direction perpendicular to the magnetization direction 3. A dust core layer 2 having a lower magnetic permeability than the laminated core 1 is provided on one surface. Hereinafter, the dust core layer 2 provided at the center of the laminated core 1 in the stacking direction is the dust core layer 2a (first dust core layer), and the dust core layer 2 provided on the plane perpendicular to the magnetization direction 3 of the laminated core 1 is the dust core layer 2b (first core). 2 dust core layers). The reactor of this embodiment is configured by combining a plurality of such basic configuration cores.

  In the basic core of the reactor core, the dust core layer 2b provided on the surface perpendicular to the magnetization direction 3 may be provided on the end surface, or may be provided at a plurality of locations. For example, when the reactor core is arranged so that the magnetization direction 3 is in the longitudinal direction, dust core layers 2b may be provided on both end surfaces in the longitudinal direction as illustrated in FIG. Moreover, the dust core layer 2b may be provided in two or more places so that the longitudinal direction is divided into three or more. Moreover, as illustrated in FIG. 3, in addition to both end faces in the longitudinal direction, the dust core layer 2 b may be provided at one place or a plurality of places so that the longitudinal direction is divided into two or more.

[Composition of Reactor]
In the reactor core according to the present embodiment, the basic configuration core illustrated in FIG. 1 is applied to the legs. Further, the basic configuration core applied to the yoke portion is a modification of the basic configuration core shown in FIG. 1, and as illustrated in FIG. It has the layer 2a and the dust core layer 2b provided in the plane (end surface) parallel to a longitudinal direction. The yoke portion is arranged so that the magnetization direction 3 passes through the dust core layer 2b provided on a plane parallel to the longitudinal direction.

  The reactor is configured using the reactor core configured by combining the basic configuration cores in this way. FIG. 5 is a diagram illustrating a reactor 10 configured by winding a coil 4 around a leg portion of a reactor core. As shown in FIG. 5, in the reactor 10, the laminated cores 1 and the dust core layers 2b are alternately arranged in the magnetic circuit. Further, only the dust core layer 2a exists in the central portion in the stacking direction in the magnetic circuit. Thereby, in the current region below the rated current, the dust core layer 2b perpendicular to the magnetization direction 3 acts as a gap, and after the laminated core 1 is magnetically saturated beyond the rated current, the dust core layer 2b is located at the center in the laminating direction. A magnetic path is formed in the dust core layer 2a that is not magnetically saturated.

  That is, in this reactor 10, in the current region below the rated current, as shown in FIG. 6, in the magnetic path 5, the arrangement of the laminated core 1 and the dust core layer 2 b is only in series with respect to the magnetization direction 3. It is formed in the surface side region. FIG. 7 shows the relationship between current and inductance in this case. However, when the current value exceeds the rated current and the laminated core 1 is magnetically saturated, the magnetic path 5 is formed in the dust core layer 2a on the center side arranged in parallel with the laminated core 1, as shown in FIG. This is because the rated current of the dust core layer 2 is higher than the rated current of the laminated core 1 because the core material of the dust core layer 2 has a structure containing many fine gaps. As a result, in this reactor 10, as shown in FIG. 9, even if the current value exceeds the rated current and the laminated core 1 is magnetically saturated, the sudden decrease in inductance that occurs without the dust core layer 2a (the broken line in FIG. 9). (Referred to), the effect of improving the DC superimposition characteristics) is shown.

  The configuration of the reactor core is not limited to the configuration illustrated in FIG. For example, the basic configuration core illustrated in FIG. 1 may be applied to the yoke portion of the reactor core. In that case, as illustrated in FIG. 2 and FIG. 3, the basic component core in which the dust core layer 2 b is disposed on both end surfaces in the longitudinal direction when the magnetization direction 3 is disposed in the longitudinal direction is illustrated on the legs. Apply. In FIG. 10, the basic configuration core shown in FIG. 1 is applied to the yoke portion, and the basic configuration core in which the dust core layer 2b is disposed on the both ends in the longitudinal direction and the two surfaces dividing the longitudinal direction is applied to the leg portion. The reactor 10 made is shown. Also in the reactor 10 shown in FIG. 10, similarly to the reactor 10 shown in FIG. 5, the laminated cores 1 and the dust core layers 2b are alternately arranged in the magnetic circuit. Further, only the dust core layer 2a exists in the central portion in the stacking direction in the magnetic circuit. As a result, even in the reactor 10 shown in FIG. 10, even if the current value exceeds the rated current and the laminated core 1 is magnetically saturated, as shown in FIG. 9, a sudden drop in inductance occurs if there is no dust core layer 2a (FIG. 9). (See the broken line in FIG. 4)) (effect of improving DC superimposition characteristics) is shown.

  On the other hand, FIG. 11 is a diagram illustrating a reactor 10 of a comparative example. Although the reactor 10 is provided with the dust core layer 2 b on the surface perpendicular to the magnetization direction 3, the dust core layer is not provided at the center in the stacking direction of the stacked core 1. In this case, as shown in FIG. 11, the arrangement of the laminated core 1 and the dust core layer 2b is always in series with the magnetization direction 3, and the dust core layer 2b having a low magnetic permeability acts as a gap. Therefore, as shown in FIG. 12, when the current value exceeds the rated current and the laminated core 1 is magnetically saturated, the inductance rapidly decreases.

[Laminated core]
In the present embodiment, the laminated core 1 is made of a silicon steel plate having excellent high-frequency magnetic properties with a plate thickness of 0.35 mm or less and a Si concentration in the range of 3.0 to 7.0 mass%. When the plate thickness exceeds 0.35 mm, the high-frequency magnetic characteristics deteriorate due to an increase in the eddy current layer. When the Si concentration is less than 3.0% by mass, the core loss increases because the specific resistance is small. If the Si concentration exceeds 7.0% by mass, the silicon steel sheet becomes very brittle, making it difficult to manufacture and handle it after manufacturing. In order to further improve the high-frequency magnetic properties, a silicon steel plate having a plate thickness of 0.2 mm or less and a Si concentration in the range of 5.0 to 7.0% by mass is desirable.

  Further, the Si concentration of the center layer and the surface layer of the plate thickness may be inclined. Thereby, the core loss in the high frequency region of 10 kHz or more is reduced, which is advantageous for reducing the high frequency iron loss. In this case, it is necessary that the Si concentration of the surface layer is in the range of 3.0 to 7.0% by mass. It is preferable that the Si concentration in the center layer is in the range of 3.0 to 4.0% by mass, and the Si concentration in the surface layer is in the range of 5.0 to 7.0% by mass.

[Dust core]
For the dust core layer 2a located at the center in the lamination direction of the laminated core 1, the multiplication value of the magnetic permeability and the thickness is 1/10 or more of the multiplication value of the magnetic permeability of the silicon steel sheet and the total thickness in the lamination direction. It is preferable to be within the following range. The magnetic permeability of the dust core layer 2a can be adjusted by the filling rate of the particles in the core material. The permeability can be increased by increasing the filling rate, and the permeability can be decreased by decreasing the filling rate. When the multiplication value of the permeability and thickness of the dust core layer 2a is less than 1/10 of the multiplication value of the permeability of the silicon steel sheet and the total thickness in the stacking direction, the inductance in the region where the inductance in the dust core layer 2a is low and exceeds the rated current is Plummet to level. Moreover, when this exceeds 2/3, since a useless part will increase in the thickness of the whole reactor core, it is not preferable. About dust core layer 2a, it is more preferable that the multiplication value of the magnetic permeability and the thickness is in the range of 1/5 or more and 1/2 or less of the multiplication value of the magnetic permeability of the silicon steel sheet and the total thickness in the stacking direction.

  For the dust core layer 2b located at one place or a plurality of places on a plane perpendicular to the magnetization direction 3, the total thickness of the magnetization direction 3 is in the range of 1/100 or more and 1/3 or less of the length in the longitudinal direction. Is preferred.

  Here, as illustrated in FIG. 1 or FIG. 3, when the magnetization direction 3 is the longitudinal direction and the dust core layer 2 b is formed on a plane that intersects (divides) the longitudinal direction of the reactor core, the magnetic path Since each crosses each dust core layer 2b at least once, the total thickness in the longitudinal direction of the dust core layer 2b is defined as the total thickness in the magnetization direction 3. A value obtained by dividing this value by the length in the longitudinal direction of the reactor core is preferably in the range of 1/100 or more and 1/3 or less.

  On the other hand, as illustrated in FIG. 4, when the magnetization direction 3 passes through a plane parallel to the longitudinal direction and the dust core layer 2b is formed on a plane (vertical cross section) parallel to the longitudinal direction of the reactor core, The road crosses the dust core layer 2b twice. Therefore, in this case, a value obtained by doubling the thickness in the core width direction of the dust core layer 2b is defined as the total thickness in the magnetization direction 3. A value obtained by dividing this value by the length in the longitudinal direction of the reactor core is preferably in the range of 1/100 or more and 1/3 or less.

  If the total thickness in the magnetization direction 3 of the dust core layer 2b is less than 1/100 of the length in the longitudinal direction, the current at which the inductance starts to decrease may shift to the low current side. Moreover, when this exceeds 1/3, there exists a possibility that the inductance in the lamination | stacking core 1 and the dust core layer 2b may fall. As for the dust core layer 2b, the total thickness in the magnetization direction 3 is more preferably in the range of 1/50 or more and 1/4 or less in the longitudinal direction.

  In the reactor core of the present embodiment, it is desirable that the laminated core 1 and the dust core layer 2 (2a, 2b) are integrated by integral molding, adhesion, or the like. As a result, the laminated surface of the laminated core 1 and the laminated cross section are in contact with the dust core layer 2 at least two surfaces, and the layer of the laminated core 1 and the dust core layer 2 support each other, so that the reactor 10 can be easily assembled. And is held stably. For that purpose, for example, a method in which a thermosetting adhesive is impregnated between the laminated core 1 and the dust core layer 2 and heat treatment is effective.

  As described above, in the reactor of this embodiment, the dust core layer 2b perpendicular to the magnetization direction acts as a gap at the rated current and lower currents, and the laminated core 1 is magnetically saturated beyond the rated current. After that, a magnetic path is formed in the dust core layer 2a that is not magnetically saturated and is located at the center in the stacking direction. Thereby, the direct current superimposition characteristic improvement effect which relieve | moderates the fall of the inductance in the area | region exceeding a rated current is shown. Furthermore, since the layer of the laminated core 1 and the dust core layer 2 support each other, and this is an integral core, the assembly of the reactor is facilitated and stably held.

[Example 1]
The reactor core of the example of the present invention was configured as shown in FIG. 5 using a laminated core made of a silicon steel plate having a plate thickness of 0.10 mm and a Si concentration of 6.5% by mass. The leg portion is provided with a dust core layer at a central portion in the stacking direction of the stacked core, in which the product of permeability and thickness is 1/2 of the product of the permeability of the silicon steel plate and the total thickness in the stacking direction. A dust core layer having a thickness of 1/20 of the longitudinal direction was provided on a plane perpendicular to the magnetization direction at one location in the center. The yoke portion is provided with a similar dust core layer in the central portion in the stacking direction, and a dust core layer whose thickness is 1/20 of the longitudinal direction on one plane parallel to the longitudinal direction (the total thickness in the magnetization direction is 1 in the longitudinal direction). / 10) was formed. About this reactor, the relationship between an electric current and an inductance was evaluated.

  As a comparative example, the relationship between current and inductance was similarly evaluated for the reactor having the configuration illustrated in FIG. The reactor reactor of this comparative example is composed of the same laminated core and dust core layer as the reactor core of the above-described embodiment of the present invention, except that the dust core layer is not provided at the central portion in the stacking direction. Coils with common specifications were used.

  As a result, as illustrated in FIG. 12, the relationship between the current and the inductance in the reactor of the comparative example was abruptly reduced when the current value exceeded the rated current. On the other hand, the relationship between the current and the inductance in the reactor of this example showed the same behavior as the comparative example shown in FIG. 12, as shown in FIG. 7, in the current region below the rated current. Further, in the current region exceeding the rated current, as shown by a solid line in FIG. 9, the decrease was more gradual than the sudden decrease in inductance in the comparative example shown in FIG. 12. Thus, it was confirmed that the sudden drop in inductance that should occur without the dust core layer 2a was alleviated.

[Example 2]
In this example, the relationship between current and inductance was evaluated for the reactors using the reactor cores A to G shown in Table 1. For the reactor cores A to G of this example, a laminated core made of a silicon steel plate having a plate thickness of 0.10 mm and a Si concentration of 6.5% by mass was used.

  As shown in Table 1, the reactor cores A to C were configured by combining the following leg portions 1 to 3 and yoke portions 1 to 3. FIG. 13 is a diagram showing the results of evaluating the relationship between current and inductance for reactors using reactor cores A to C. FIG.

  As shown in FIG. 1, the leg portions 1 to 3 are configured such that a dust core layer is provided on a central portion in the stacking direction of the above-described stacked core and a plane perpendicular to one magnetization direction in the central portion in the longitudinal direction. It was. The thickness of the dust core layer provided at the center in the longitudinal direction was 1/20 of the length in the longitudinal direction. In addition, the product of the permeability and thickness of the dust core layer provided in the central portion of the laminated core in the stacking direction is set to the product of the permeability of the silicon steel plate and the total thickness in the stacking direction. It changed with 1/3, 1/10, 1/15 for every leg part 1-3).

  Further, as shown in FIG. 4, the yoke portions 1 to 3 have a configuration in which a dust core layer is provided on a central portion in the stacking direction of the stacked core and a flat surface (end surface) on one side parallel to the longitudinal direction. The thickness of the dust core layer formed on one plane parallel to the longitudinal direction was 1/20 of the length in the longitudinal direction (the total thickness in the magnetization direction was 1/10 of the length in the longitudinal direction). In addition, the multiplication value of the permeability and thickness of the dust core layer provided in the central portion of the lamination core in the lamination direction is set to the multiplication value of the permeability of the silicon steel plate and the total thickness in the lamination direction. The yoke portions 1 to 3) were changed to 1/3, 1/10, and 1/15.

  As shown in Table 1, the reactor anchors D to G were configured by combining the following leg portions 4 to 7 and the yoke portion 4. FIG. 14 is a diagram showing the results of evaluating the relationship between current and inductance for reactors using reactor cores D to G.

  As shown in FIG. 1, the leg portions 4 to 7 are configured such that a dust core layer is provided on a central portion in the stacking direction of the above-described stacked core and a surface perpendicular to the magnetization direction at one location in the central portion in the longitudinal direction. It was. The multiplication value of the magnetic permeability and thickness of the dust core layer provided in the central portion of the lamination core in the lamination direction was set to ½ of the multiplication value of the permeability of the silicon steel sheet and the total thickness in the lamination direction. Further, the thickness of the dust core layer provided in the central portion in the longitudinal direction is set to 1/2, 1/3, 1 / for each embodiment of the leg portions (leg portions 4 to 7) with respect to the length in the longitudinal direction. It was changed to 100, 1/150.

  Further, as shown in FIG. 4, the yoke portion 4 has a configuration in which a dust core layer is provided on a central portion in the stacking direction of the stacked core and a flat surface on one side parallel to the longitudinal direction. The multiplication value of the magnetic permeability and thickness of the dust core layer provided in the central portion of the lamination core in the lamination direction was set to ½ of the multiplication value of the magnetic permeability of the silicon steel sheet and the total thickness in the lamination direction. The thickness of the dust core layer formed on one side plane parallel to the longitudinal direction was 1/20 of the length in the longitudinal direction (the total thickness in the magnetization direction was 1/10 of the length in the longitudinal direction).

  As shown in FIG. 13 and FIG. 14, the reactor using the reactor cores A, B, E and F of the present invention has a gradual decrease in inductance in the region exceeding the rated current, and is necessary and sufficient. It was confirmed that the quantity superposition characteristics were exhibited. On the other hand, in the reactor using the reactor core C of the comparative example, it was confirmed that the inductance drop in the region exceeding the rated current was abrupt and the DC superposition characteristics were insufficient. In the reactor using the reactor core D of the comparative example, it was confirmed that the inductance below the rated current was low and the direct current superposition characteristics were insufficient. Moreover, in the reactor using the reactor core G of the comparative example, it was confirmed that the current value at which the inductance is reduced is low and the direct current superposition characteristics are insufficient.

1 laminated core 2 dust core layer
2a Dust core layer (first dust core layer)
2b Dust core layer (second dust core layer)
3 Magnetization direction
4 Coil 5 Magnetic path

Claims (8)

A laminated core formed by laminating silicon steel sheets having a plate thickness of 0.35 mm or less and a Si concentration within a range of 3.0 to 7.0% by mass;
A first dust core layer provided in a central portion in the stacking direction of the stacked core;
A second dust core layer provided at one or a plurality of locations on a plane perpendicular to the magnetization direction of the laminated core;
Reactor is characterized by comprising.   The reactor core according to claim 1, wherein the first dust core layer and the second dust core layer are integrated or connected. The multiplication value of the permeability and thickness of the first dust core layer is in the range of 1/10 or more and 2/3 or less of the multiplication value of the permeability of the silicon steel sheet and the total thickness in the stacking direction,
The reactor core according to claim 1 or 2, wherein the total thickness in the magnetization direction of the second dust core layer is in the range of 1/100 or more and 1/3 or less of the length in the longitudinal direction.   The reactor core according to any one of claims 1 to 3, wherein when the magnetization direction is the longitudinal direction, both end faces in the longitudinal direction are the second dust core layers.   The surface provided in one place or a plurality of places which divides the longitudinal direction when the magnetization direction is the longitudinal direction is the second dust core layer. Reach Turkey as described in.   When the magnetization direction is the longitudinal direction, both end surfaces in the longitudinal direction and surfaces provided at one place or a plurality of places dividing the longitudinal direction are the second dust core layer. 4. The reactor core according to any one of 3 above.   The reactor core according to any one of claims 1 to 3, wherein when the magnetization direction passes through a plane parallel to the longitudinal direction, the second dust core layer is formed on the plane.   The Si concentration of the surface layer of the laminated core is higher than the Si concentration of the center layer, and the magnetic permeability of the first dust core layer and the second dust core layer is lower than the magnetic permeability of the silicon steel plate. 8. The reactor according to any one of 7 above.

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