JP6168378B2 - Wire ring parts - Google Patents

Description

  The present invention relates to a wire ring component in which at least a part of a coil is embedded in a soft magnetic material.

  Patent Document 1 discloses a reactor in which a core made of a magnetic powder mixed resin in which magnetic powder is dispersed in an insulating resin is embedded with a coil that generates a magnetic flux when energized.

  Further, Patent Document 1 discloses a plurality of plate-like heat radiation fins made of a material such as aluminum having a thermal conductivity higher than that of the core, the main surface of which is parallel to the axis of the coil, and the axis is the center. The structure of the reactor which can cool the heat | fever generate | occur | produced from the coil effectively and can prevent the fall of an inductance is provided by providing in a core so that it may become radial shape.

JP 2010-182941 A

  As described in Patent Document 1, in a reactor having a structure in which the periphery of a coil wound in a cylindrical shape is embedded in a core and stored in the case, heat generated in the coil reaches the case through the core. However, in such a heat flow path, the influence of the core portion having a high thermal resistance becomes large.

  That is, the thermal conductivity of the core is about 3 to 6 W / (m · K) although it is higher than that of general plastics, while the coil is generally made of copper having a low electrical resistance, and its thermal conductivity. Is as high as 400 W / (m · K), and the case is made of, for example, aluminum having a high thermal conductivity of 96 W / (m · K). Therefore, a core having a relatively high thermal resistance hinders heat dissipation.

  Therefore, as described in Patent Document 1, using a configuration in which a heat radiating fin made of a non-magnetic material such as aluminum is used in the core can improve heat dissipation from the coil to the case. Therefore, the volume ratio occupied by the soft magnetic material decreases, and there is a problem that the inductance and the direct current superimposition characteristics are degraded.

  Further, while the heat generated in the coil is transmitted through the plate-like heat radiating fins, the heat is dissipated from the surface of the heat radiating fins to the core, so that there is a problem that it is difficult to sufficiently radiate the heat to the case.

  Accordingly, an object of the present invention is to improve heat dissipation from a coil, that is, a winding without causing a decrease in inductance or DC superimposition characteristics.

A composite magnetic body mainly containing soft magnetic powder and a binder, a winding embedded in at least a part of the composite magnetic body, and at least one of the entire inner peripheral surface and the entire outer peripheral surface of the winding. a cylindrical heat transfer soft magnetic material be placed in the heat transfer soft magnetic body is connected to the heat radiation path to the composite magnetic body outside, the heat transfer soft magnetic material is heat than the composite magnetic body The present invention solves the above-described problems by a wire ring component having high conductivity.

  Replacing a part of the composite magnetic material surrounding the winding wound with the conductor wire with a heat transfer soft magnetic material having higher heat conductivity than the composite magnetic material, heat transfer to the heat dissipation path such as a case with high heat conductivity, water cooling tube, etc. By connecting the soft magnetic material, the thermal conductivity from the winding to the heat dissipation path can be enhanced without causing a decrease in inductance or DC superimposition characteristics.

  For example, an electromagnetic steel plate or a dust core can be used as the heat transfer soft magnetic material, and a soft magnetic material having higher saturation magnetization and permeability than the composite magnetic material can be selected. It is also possible to improve. Therefore, the volume ratio of the heat transfer soft magnetic material to the composite magnetic material is large, and the area in contact with the composite magnetic material can be reduced, so that the heat from the winding surface passes through the surface of the heat transfer soft magnetic material. It is less likely to dissipate to the body, and can be efficiently transmitted to the heat transfer soft magnetic material.

  That is, by replacing the composite magnetic material with low thermal conductivity with a heat transfer soft magnetic material with high thermal conductivity, the heat of the coil can be effectively transferred to the case, and a non-magnetic heat radiating member such as aluminum It is possible to form a heat flow path that can sufficiently dissipate heat without causing problems such as a decrease in magnetic properties and an increase in eddy current loss caused by providing the inside of the composite magnetic body.

  In addition, since the composite magnetic material is filled in the gap between the heat transfer soft magnetic material, it can have both magnetic properties and heat dissipation, so there is no need to devise any special measures on the magnetic circuit or heat dissipation circuit. The design and manufacturing process can be simplified, leading to cost reduction.

Also, when a dust core or laminated magnetic steel sheet is used as the heat transfer soft magnetic body, the heat transfer soft magnetic body is embedded in the composite magnetic body, thus preventing chipping of the dust core and peeling of the laminated magnetic steel sheet. Can do.

  Furthermore, even if heat is generated inside the soft magnetic core, if the winding and the heat transfer soft magnetic material are in close contact with each other over a wide area as much as possible, the winding has extremely high thermal conductivity. The heat inside the soft magnetic core can be quickly radiated by the heat transfer soft magnetic material having a high thermal conductivity.

  The frequency of the alternating current flowing through the winding is 1 kHz or more and 100 kHz or less, and the peak value excluding frequency components higher than 100 kHz is 20 A or more and 500 A or less among the current flowing through the winding. desirable.

  Under the conditions often used for such booster circuit reactors, the heat generation from the windings is larger than the heat generation from the composite magnetic material, so that the heat dissipation effect of the present invention is greatly exerted.

  Moreover, it is desirable that the minimum width of the cross section of the heat transfer soft magnetic body perpendicular to the heat flow path flowing from the winding to the heat dissipation path is 1 mm or more.

  By increasing the minimum width of the cross section perpendicular to the heat flow path in the heat transfer soft magnetic body, the contact area between the heat transfer soft magnetic body and the composite magnetic body can be reduced, and the heat transferred through the heat transfer soft magnetic body can be reduced. By suppressing the dissipation to the composite magnetic body, the heat of the winding surface is efficiently radiated through the heat transfer soft magnetic body.

  Further, the surface area of the heat transfer soft magnetic body adjacent to the surface of the winding and the cross-sectional area of the heat transfer soft magnetic body perpendicular to the heat flow path flowing from the winding to the heat dissipation path are It is desirable that it is at least 2% or more of the area of the peripheral surface or the entire outer peripheral surface.

  The surface area of the heat transfer soft magnetic body adjacent to the surface of the winding and the cross-sectional area perpendicular to the heat flow path in the heat transfer soft magnetic body are at least 2% of the area of the entire inner peripheral surface or outer peripheral surface of the winding By doing so, the heat of the winding surface is efficiently transferred to the heat transfer soft magnetic material, and the cross-sectional area perpendicular to the heat flow path in the heat transfer soft magnetic material is increased, that is, the heat transfer soft magnetic material and the composite magnetism are increased. By reducing the contact area of the body, the heat transmitted through the heat transfer soft magnetic body is prevented from being dissipated to the composite magnetic body, and the heat on the winding surface is efficiently radiated through the heat transfer soft magnetic body.

Further, example Bei a case for accommodating the heat transfer soft magnetic material and said composite magnetic body as the heat dissipation path, the heat transfer soft magnetic body is in contact with the casing, the winding is supported by the heat transfer soft magnetic body Preferably, the case is provided with means for fixing the heat transfer soft magnetic material.

  Since the heat transfer soft magnetic material of the present invention has a portion close to the winding, it is also possible to support the winding with the heat transfer soft magnetic material. The heat transfer soft magnetic material is provided in the case. If it is fixed with holes, protrusions, grooves, irregularities, adhesives, etc., the windings will not be displaced, so the workability when forming a composite magnetic material is improved.

  According to the present invention, it is possible to provide a wire ring component with improved heat dissipation from a winding without causing a decrease in inductance or DC superimposition characteristics.

Sectional drawing containing the winding axis | shaft of the winding center which shows an example of the wire ring components in this invention. Sectional drawing containing the winding axis | shaft of the coil | winding center which shows another example of the wire ring components in this invention. Sectional drawing containing the winding axis | shaft of the winding center which shows another example of the wire ring components in this invention. Sectional drawing perpendicular | vertical to the winding axis which shows another example of the wire ring components in this invention. The figure which shows the relationship between the heat conductivity of the heat-transfer soft magnetic body in this invention, and the temperature rise value of the coil inner peripheral surface center part. The figure which shows the relationship between the thickness of the heat-transfer soft magnetic body in this invention, and the temperature rise value of the coil inner peripheral surface center part.

  An embodiment of the present invention will be described.

  FIG. 1 is a cross-sectional view including a winding axis at the center of a winding showing an example of a wire ring component according to the present invention. A winding 1 formed by winding a conductor wire so as to go around a cylindrical surface is embedded in a composite magnetic body 2 mainly containing soft magnetic powder and a binder, and the bottom of the winding 1, that is, the entire end in the winding axis direction. The heat transfer soft magnetic body 3 is provided so as to be in contact with the winding 1, the composite magnetic body 2, and the case 4 for housing the heat transfer soft magnetic body 3 are provided. The inner surface of the case 4 and the bottom of the heat transfer soft magnetic body 3 are provided. It touches.

  The wire ring component shown in FIG. 1 has, for example, a heat transfer soft magnetic body 3 fixed to the bottom of the case 4 in advance, a winding 1 fixed on the heat transfer soft magnetic body 3, and an uncured composite magnetic body. 2 is poured into a case 4 and the composite magnetic body 2 is cured by embedding the winding 1 and the heat transfer soft magnetic body 3. As a means for fixing, adhesion, positioning by uneven shape, or the like can be used, but is not limited thereto.

  After the heat transfer soft magnetic body 3 is placed at the bottom of the case 4 and the uncured composite magnetic body 2 is poured into the case 4 and cured until a part of the heat transfer soft magnetic body 3 is buried. Alternatively, the winding 1 is placed on the heat transfer soft magnetic body 3, and the uncured composite magnetic body 2 is poured until the winding 1 and the heat transfer soft magnetic body 3 are embedded and cured.

  The composite magnetic body 2 mainly contains soft magnetic powder and a binder, and a non-magnetic powder or the like may be appropriately added in order to adjust the fluidity when injected into the case 4.

  Examples of the soft magnetic powder include soft magnetic metal powders such as Fe-Si, Fe-Si-B, Fe-Si-Al, and Fe-Si-Cr, and ferrite pulverized powder. However, heat dissipation is regarded as important. For high current applications, soft magnetic metal powder is preferably used.

  Moreover, since a binder can be filled with a soft magnetic powder without a gap when a liquid epoxy resin or the like is used, it has good heat dissipation and is preferably used.

  Examples of the heat transfer soft magnetic body 3 include a material having a thermal conductivity higher than that of the composite magnetic body 2, such as a laminated electromagnetic steel sheet and a dust core. The thermal conductivity in the in-plane direction of the laminated electrical steel sheet is 83 W / (m · K), and the thermal conductivity of the dust core varies depending on the composition. For example, in Fe-3 mass% Si, 27 W / (m · K), Fe— Although it is 15 W / (m · K) at 6.5 mass% Si, both can be sufficiently higher than the thermal conductivity of the composite magnetic material of 3 to 6 W / (m · K).

  FIG. 2 is a cross-sectional view including a winding axis at the center of winding, showing another example of the wire ring component according to the present invention. Winding 1 formed by winding a conductor wire so as to go around the cylindrical surface is embedded in a composite magnetic body 2 mainly containing soft magnetic powder and a binder, and heat transfer is made so as to be in contact with the entire inner peripheral surface of winding 1. A soft magnetic body 3 is provided, a winding 1, a composite magnetic body 2, and a case 4 that houses the heat transfer soft magnetic body 3 are provided, and the inner surface of the case 4 and the bottom of the heat transfer soft magnetic body 3 are in contact with each other.

  The wire ring component shown in FIG. 2 can be produced in the same procedure as in FIG. 1, but the winding 1 may be fixed to the heat transfer soft magnetic body 3 in advance.

  FIG. 3 is a cross-sectional view including a winding shaft at the center of winding showing another example of the wire ring component in the present invention, and FIG. 4 is a cross-sectional view perpendicular to the winding shaft showing another example of the wire ring component in the present invention. Show.

  This embodiment differs from the embodiment of FIGS. 1 and 2 in that a groove 41 is provided in the case 4 and a heat transfer soft magnetic body 3 is formed of a molded member such as a laminated electrical steel sheet.

  3 and 4, for example, the heat transfer soft magnetic body 3 is inserted along the groove 41 of the case 4, the winding 1 is inserted into the heat transfer soft magnetic body 3, and an uncured composite is obtained. It can be created by pouring the magnetic body 2 into the case 4 until the winding 1 is embedded and curing.

  Since the heat transfer soft magnetic body 3 is fixed by the groove 41 of the case 4 and the winding 1 is fixed by the heat transfer soft magnetic body, the heat transfer soft magnetic body 3 is poured when the uncured composite magnetic body 2 is poured into the case 4. It is possible to prevent the displacement of the body 3 and the winding 1 from occurring.

  Further, the height of the core portion 31 corresponding to the inner peripheral portion of the winding 1 in the heat transfer soft magnetic body 3 may be set in accordance with the inductance required for the wire ring component and the DC superposition characteristics.

  The heat-resistant temperature required for wire ring parts varies depending on the application, but considering long-term reliability, it is desirable that the temperature rise due to heat generation is low, so it is necessary to improve heat dissipation and suppress the temperature rise during use . Since the heat resistance of a general electronic component is designed at, for example, about 80 to 150 ° C., the temperature when the wire ring component is used is preferably within this range.

  An example of the present invention will be described with reference to the drawings.

Example 1
FIG. 1 is a cross-sectional view including a winding axis at the center of a winding showing an example of a wire ring component according to the present invention.

  Winding 1 comprises a 34-turn round wire with a cross section of 3 mm, an outer diameter of 85 mm, an inner diameter of 51 mm, and a height of 22 mm. The aluminum case 4 has an inner diameter of 105 mm and a height of 40 mm. The inside of the case 4 was filled with the composite magnetic body 2 and the winding was formed in a structure arranged in the center of the case 4. A heat transfer soft magnetic material 3 is installed between the bottom of the winding 1 and the bottom of the aluminum case.

  The thermal conductivity of the round wire constituting the winding is 400 W / (m · K), the thermal conductivity of the case is 96 W / (m · K), and the thermal conductivity of the composite magnetic material is 3 W / (m · K). Yes, the temperature rise value of the wire ring component when the DC current is superimposed on the AC current of 10 kHz, 60 Ap-p with 80 A, that is, the thermal conductivity of the heat transfer soft magnetic material and the inside of the winding in the present invention FIG. 5 shows the relationship with the temperature rise value at the center of the peripheral surface.

  The temperature of the element is measured by a thermocouple embedded in the inside, but there are variations in the accuracy and mounting position of the thermocouple itself, and the thermal conductivity without using a heat transfer soft magnetic material is 3 W / (m · If the difference between the temperature rise value in the case of K) and the temperature rise value in the case where the thermal conductivity using the heat transfer soft magnetic material is greater than 3 W / (m · K) is 5K or more, there is a significant difference. It can be seen that there is.

  From the result of FIG. 5, when the heat conductivity of the heat transfer soft magnetic material is 10 W / (m · K) or more, the temperature rise value is more than 5 K than when the heat transfer soft magnetic material is not used. Therefore, it can be seen that a sufficient heat dissipation effect is obtained.

  In addition, it is possible to further suppress the temperature rise value by installing a cooling means in the case 4.

(Example 2)
FIG. 2 is a cross-sectional view including a winding axis at the center of a winding showing an example of a wire ring component according to the present invention.

  Winding 1 comprises a 34-turn round wire with a cross section of 3 mm, an outer diameter of 85 mm, an inner diameter of 51 mm, and a height of 22 mm. The aluminum case 4 has an inner diameter of 105 mm and a height of 40 mm. The inside of the case 4 was filled with the composite magnetic body 2 and the winding was formed in a structure arranged in the center of the case 4. A cylindrical heat transfer soft magnetic body 3 is installed between the inner peripheral surface of the winding 1 and the bottom of the aluminum case. Here, since the cross section perpendicular to the heat flow path from the winding 1 of the heat transfer soft magnetic body to the case 4 is a horizontal plane in FIG. 2, the minimum width of the cross section is the thickness of the cylindrical heat transfer soft magnetic body 3. equal.

  The thermal conductivity of the round wire constituting the winding is 400 W / (m · K), the thermal conductivity of the case is 96 W / (m · K), the thermal conductivity of the composite magnetic material is 3 W / (m · K), The heat conductivity of the heat transfer soft magnetic material is 20 W / (m · K), and the temperature rise value of the wire ring component when the coil is energized with 80 A of DC current superimposed on AC current of 10 kHz, 60 Ap-p. That is, FIG. 6 shows the relationship between the thickness of the heat transfer soft magnetic material and the temperature rise value at the central portion of the inner surface of the winding in the present invention.

  As in Example 1, the temperature rise value when the heat transfer soft magnetic material when the thickness was 0 mm and the heat transfer soft magnetic material when the thickness was greater than 0 mm were used. If the difference in temperature rise value is 5K or more, it can be considered that there is a significant difference.

  From the result of FIG. 6, if the thickness of the heat transfer soft magnetic body 3 is 1 mm or more, more desirably 3 mm or more, the temperature rise value is 5 K or more lower than the case where the heat transfer soft magnetic body is not used. It can be seen that a good heat dissipation effect is obtained.

That is, the area of the inner peripheral surface of the winding 1 is π × 51 mm × 40 mm, that is, about 6409 mm ² , and since the heat flow path is directed from the winding 1 toward the bottom of the case 4, the direction of the heat flow path is perpendicular Since the cross-sectional area of the heat transfer soft magnetic body 3 is π × (51 mm ÷ 2) ² −π × (49 mm / 2) ² , that is, about 157 mm ^2, it is perpendicular to the heat flow path in the heat transfer soft magnetic body 3. It can be seen that when the cross-sectional area is at least 2% or more, more preferably 7% or more, of the area of the inner peripheral surface or the entire outer peripheral surface of the winding 1, a sufficient heat dissipation effect can be obtained.

  The surface area of the heat transfer soft magnetic body 3 adjacent to the surface of the winding 1 is equal to or larger than the cross-sectional area described above in order to efficiently transfer the heat of the surface of the winding 1 to the heat transfer soft magnetic body 3. It is required to be.

  Moreover, it is possible to further suppress the temperature rise value by installing a cooling means in the case 4.

1 Winding 2 Composite Magnetic Body 3 Heat Transfer Soft Magnetic Body 31 Core 4 Case 41 Groove

Claims (5)

And composite magnetic body containing mainly binder with soft magnetic powder, and windings set embedded in the composite magnetic body is embedded in the composite magnetic body, disposed in contact with the inner peripheral surface entire surface of the winding A cylindrical heat transfer soft magnetic body, the heat transfer soft magnetic body is filled with the composite magnetic body, and is connected to a heat dissipation path to the outside of the composite magnetic body. A wire ring component having a higher thermal conductivity than the composite magnetic material.   The frequency of the alternating current applied to the winding is 1 kHz or more and 100 kHz or less, and the peak value excluding the frequency component higher than 100 kHz among the current supplied to the winding is 20 A or more and 500 A or less. The wire ring part according to claim 1.   The wire ring component according to claim 1 or 2, wherein a minimum width of a cross section of the heat transfer soft magnetic material perpendicular to a heat flow path flowing from the winding to the heat dissipation path is 1 mm or more. Sectional area of the front heat flow path flowing from Kimaki line to the heat sink path perpendicular the heat transfer soft body, characterized in that at least 2% or more of the area of the entire inner peripheral surface or outer peripheral surface of the winding The wire ring component according to claim 1 or 2.   A case for accommodating the composite magnetic body and the heat transfer soft magnetic body as the heat dissipation path; the heat transfer soft magnetic body in contact with the case; and the winding supported by the heat transfer soft magnetic body; The wire ring component according to any one of claims 1 to 4, wherein means for fixing the heat transfer soft magnetic material is provided in the wire ring component.

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