JP2017139310A - Reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reactor which can suppress vibration during driving so as to reduce noise.SOLUTION: A reactor 1 comprises: a coil 2 having a winding part 2c; a magnetic core 3 having an inner core part arranged inside the winding part and an outer core part 32 arranged outside the winding part; and a placing member 4 on which an assembly 10 formed by the coil and the magnetic core is placed. The magnetic core 3 comprises: a plurality of core pieces; and a gap formed between the core pieces. The outer core part 32 comprises: a lower face placed on the placing member 4; and an upper face opposite to the lower face. The lower face and the upper face of the outer core part 32 are each fixed to the placing member 4 via a stay 80.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a reactor that is used in a vehicle-mounted DC-DC converter or a component of a power converter mounted on a vehicle such as a hybrid vehicle.

  A reactor is one of the parts of a circuit that performs a voltage step-up operation or a voltage step-down operation. For example, Patent Document 1 discloses a technique related to a reactor including a coil and a magnetic core on which the coil is disposed.

  Patent Document 1 includes a coil, an annular magnetic core having an inner core portion disposed inside the coil and an outer core portion exposed from the coil, and a case that houses a combination of the coil and the magnetic core. A reactor provided is disclosed. The inner core portion is a laminated body in which divided cores (core pieces) and gap plates made of ceramics or resin are alternately laminated. In this reactor, an adhesive layer is formed by adhering the bottom plate portion of the case and the lower surface of the outer core portion contacting the bottom plate portion with an adhesive, and the lower surface of the outer core portion is fixed to the case (bottom plate portion). ing.

JP2013-4931A

  It is desired to reduce noise caused by vibration during reactor driving.

  The reactor is driven by energizing a coil with a current of a predetermined frequency and exciting the magnetic core. When the magnetic core is composed of a plurality of core pieces and a gap is provided between the core pieces, when the reactor is driven, the magnetic core vibrates due to an electromagnetic attractive force acting between adjacent core pieces across the gap, Noise may be generated.

  The present invention has been made in view of the above circumstances, and one of its purposes is to provide a reactor that can suppress vibration during driving and reduce noise.

  A reactor according to an aspect of the present invention includes a coil having a winding portion, an inner core portion disposed inside the winding portion, and a magnetic core having an outer core portion disposed outside the winding portion. And a mounting member on which a combination of the coil and the magnetic core is mounted. The magnetic core has a plurality of core pieces and a gap provided between the core pieces. The said outer core part has the lower surface mounted in the mounting member, and the upper surface on the opposite side. And the lower surface and upper surface of the said outer core part are being respectively fixed with respect to the mounting member.

  The reactor can suppress vibration during driving and can reduce noise.

It is a schematic perspective view of the reactor of Embodiment 1. 1 is a schematic exploded perspective view of a reactor according to a first embodiment. FIG. 2 is a schematic exploded perspective view of a combined body in the reactor according to the first embodiment. FIG. 4 is a schematic side cross-sectional view of the reactor cut along line IV-IV shown in FIG. 1. It is a schematic side sectional view showing another example of the fixing structure of the outer core portion in the reactor of the first embodiment. FIG. 5 is a schematic top cross-sectional view of a reactor according to a second embodiment. It is a schematic top sectional view showing another example of the reactor of the second embodiment.

  The inventors focused on the relationship between the reactor driving frequency and the natural frequency, and examined the influence of the driving frequency on the vibration characteristics (vibration / noise) of the reactor. As a result, the following knowledge was obtained.

  In a reactor used in a power conversion device mounted on a hybrid vehicle or an electric vehicle, a driving frequency of a current supplied to a coil is about 5 kHz to 10 kHz. When the driving frequency band of the reactor and the natural frequency of the reactor overlap, a resonance phenomenon occurs, and vibration and noise increase due to resonance. As in the prior art, in a reactor including a magnetic core in which a gap plate is interposed between core pieces, the core piece hardly vibrates and the natural frequency tends to be high due to the gap plate interposed. For this reason, the natural frequency of the reactor is set higher than the drive frequency, so that the resonance phenomenon hardly occurs and the problem of vibration and noise during the reactor drive hardly occurs. However, when a gap is provided between the core pieces and no gap plate is interposed, the core pieces tend to vibrate and the natural frequency tends to be low. Therefore, there is a possibility that the natural frequency of the reactor overlaps with the driving frequency band, a resonance phenomenon occurs, and vibration and noise become remarkable.

  The inventors of the present invention have found that the vibration at the time of driving can be suppressed and the noise due to the vibration can be reduced by devising the fixing structure of the magnetic core and making the natural frequency of the reactor out of the driving frequency band. The present invention has been made based on the above findings. First, embodiments of the present invention will be listed and described.

[Description of Embodiment of the Present Invention]
(1) The reactor which concerns on 1 aspect of this invention has the coil which has a winding part, the inner core part arrange | positioned inside the said winding part, and the outer core part arrange | positioned on the outer side of the said winding part. A magnetic core; and a mounting member on which a combination of the coil and the magnetic core is mounted. The magnetic core has a plurality of core pieces and a gap provided between the core pieces. The said outer core part has the lower surface mounted in the mounting member, and the upper surface on the opposite side. And the lower surface and upper surface of the said outer core part are being respectively fixed with respect to the mounting member.

  According to the reactor, both the lower surface and the upper surface of the outer core portion are fixed to the mounting member, so that the vibration of the outer core portion (magnetic core) due to the electromagnetic attractive force can be effectively suppressed. By fixing both the lower surface and the upper surface of the outer core portion, the natural frequency of the reactor becomes higher than when only one surface is fixed, and the natural frequency can be shifted to the high frequency side. Therefore, the natural frequency of the reactor can be made higher than the driving frequency (5 kHz to 10 kHz), the natural frequency can be out of the driving frequency band, and resonance between the natural frequency and the driving frequency can be avoided. Therefore, the reactor can avoid the resonance phenomenon between the natural frequency and the drive frequency, can suppress vibration during driving, and can reduce noise due to vibration.

  Moreover, the said reactor does not interpose gap plates, such as ceramics, between the core pieces which comprise a magnetic core. Therefore, there is no need to prepare a gap plate, and the number of parts can be reduced compared to the conventional case, and the process of bonding the core piece and the gap plate with an adhesive can be omitted. Improvements can be made.

  (2) As one form of the reactor, the natural frequency of the reactor is higher than the drive frequency and higher than 10 kHz.

  Since the natural frequency of the reactor is more than 10 kHz, it can be sufficiently higher than the driving frequency (5 kHz to 10 kHz), so that vibration during driving can be effectively suppressed and noise due to vibration can be further reduced. A more preferable natural frequency of the reactor is 11 kHz or more.

  (3) As one form of the said reactor, it is mentioned that the said mounting member is a case which has the baseplate part in which the said assembly is mounted, and the side wall part surrounding the circumference | surroundings of the said assembly. In this case, it is possible to include a sealing resin that fills the case and seals the assembly, and the gap is filled with the sealing resin.

  The combined body can be integrated with the sealing resin by being housed in the case and sealed with the sealing resin. It also protects the union from the external environment. In this case, in the manufacturing process, when the case is filled with the sealing resin, the unsolidified resin flows into the gap between the core pieces, and the gap can be filled with the sealing resin.

  (4) As one form of the reactor, an adhesive layer that adheres the lower surface of the outer core portion and the mounting member, and an upper surface of the outer core portion, and the upper surface of the outer core portion is set as the mounting member. And a fixing device that fixes the device to the above.

  By providing an adhesive layer between the lower surface of the outer core portion and the mounting member, the lower surface of the outer core portion can be fixed to the mounting member. By providing the fixture on the upper surface of the outer core portion, the upper surface of the outer core portion can be fixed to the mounting member via the fixture. Examples of the fixture include a stay and a leaf spring that are disposed on the upper surface of the outer core portion and are fixed to the mounting member. If it is a leaf | plate spring, the upper surface of an outer core part can be pressed to the mounting member side, and the upper surface of an outer core part can be fixed more firmly with respect to a mounting member. In addition, a stay and a leaf spring are disposed on the upper surface of the outer core portion, and the upper surface of the outer core portion and the stay and the leaf spring are bonded to each other with an adhesive layer so that the upper surface of the outer core portion is more firmly attached to the mounting member. Can be firmly fixed. In addition, when the mounting member is a case and has a cover attached to the case, this cover can be used as a fixture. For example, the upper surface of the outer core portion and the case are bonded with an adhesive to form an adhesive layer, whereby the upper surface of the outer core portion can be fixed to the case (mounting member) via the cover.

  (5) As one form of the reactor, the mounting member is a case having a bottom plate portion on which the combination is placed and a side wall portion surrounding the combination, and the magnetic core includes a pair It is mentioned that it is a cyclic | annular magnetic core which has the said inner core part and a pair of said outer core part arrange | positioned at the both ends of these inner core parts. In this case, it is mentioned that the case has a protruding portion that protrudes from the inner surface of the side wall portion and contacts an inner end surface of the outer core portion that faces the inner core portion.

  A protrusion is provided on the side wall portion of the case so as to protrude from the inner surface, and the protrusion is in contact with the inner end surface of the outer core portion, whereby vibration of the outer core portion due to electromagnetic attraction can be further suppressed. Therefore, the vibration of the outer core portion during driving can be effectively suppressed, and noise due to vibration can be further reduced.

[Details of the embodiment of the present invention]
Specific examples of the reactor according to the embodiment of the present invention will be described below with reference to the drawings. The same reference numerals in the figure indicate the same names. In addition, this invention is not limited to these illustrations, is shown by the claim, and intends that all the changes within the meaning and range equivalent to a claim are included.

[Embodiment 1]
<Reactor configuration>
The reactor of Embodiment 1 is demonstrated with reference to FIGS. As shown in FIGS. 1 to 4, the reactor 1 of the first embodiment has a coil 2 having a winding part 2 c, an inner core part 31 disposed inside the winding part 2 c, and the outside of the winding part 2 c. The magnetic core 3 which has the outer core part 32 arrange | positioned, and the mounting member (in this example, case 4) in which the assembly of the coil 2 and the magnetic core 3 is mounted are provided. As shown in FIGS. 3 and 4, the inner core portion 31 includes a plurality of inner core pieces 31 m and a gap 31 g provided between the inner core pieces 31 m. One of the features of the reactor 1 is that the lower surface of the outer core portion 32 that is placed on the placement member (the bottom plate portion 40 of the case 4) and the upper surface on the opposite side of the placement member (case 4) And is fixed. In the following description, the mounting member (the bottom plate portion 40 of the case 4) side is described as “lower”, and the opposite side is described as “upper”. Hereinafter, the configuration of the reactor will be described in detail.

(coil)
As shown in FIGS. 1 to 3, the coil 2 includes a pair of winding portions 2 c and 2 c formed by winding a winding, and a connecting portion 2 r that connects both the winding portions 2 c. The winding part 2c is formed in a cylindrical shape by winding the winding spirally, and both winding parts 2c are arranged side by side (parallel) so that their axes are parallel to each other. The winding is a coated flat wire (so-called enameled wire) having a flat wire conductor (copper or the like) and an insulating coating (polyamideimide or the like) on the outer periphery of the conductor. The coil 2 is an edgewise coil that is formed by one continuous winding and the winding part 2c is formed in a square tube shape.

  The winding end portion 2e is drawn out from the winding portion 2c in an appropriate direction, the insulating coating at the tip thereof is peeled off, and a terminal fitting (not shown) is connected to the conductor. The coil 2 is electrically connected to an external device (not shown) such as a power source via a terminal fitting.

(Magnetic core)
2 and 3, the magnetic core 3 is disposed outside the coil 2 (winding portion 2c) and a pair of inner core portions 31 disposed inside the coil 2 (winding portion 2c). And a pair of outer core portions 32. Each inner core part 31 is a part in which the coil 2 is arrange | positioned, respectively located inside each winding part 2c arrange | positioned side by side. The inner core portion 31 may have a part of the end portion in the axial direction protruding from the winding portion 2c. Each outer core part 32 is a part which is located outside both winding parts 2c, and the coil 2 is not substantially disposed (that is, protrudes (exposes) from the winding part 2c). In the magnetic core 3, the outer core portions 32 are arranged so as to sandwich the inner core portions 31 arranged side by side from both ends, and both end surfaces of the inner core portions 31 face the inner end surface 32 e of the outer core portion 32, respectively. Are formed in an annular shape. In the magnetic core 3, when the coil 2 is energized and excited, a magnetic flux flows and a closed magnetic path is formed.

(Inner core part)
As shown in FIG. 3, the inner core portion 31 has a plurality of inner core pieces 31m, and a gap 31g (see FIG. 4) is provided between the inner core pieces 31m. In this example, the gap 31g is filled with a sealing resin 6 described later. The gap 31g may be a space (air gap) without being filled with the sealing resin 6.

  The shape of the inner core portion 31 is a shape corresponding to the shape of the winding portion 2c. In this example, the inner core portion 31 is a quadrangular columnar body, and the inner core piece 31m is a quadrangular columnar piece. Moreover, the inner core part 31 is arrange | positioned in the state in which the gap 31g was provided between the some inner core pieces 31m. In this example, the number of inner core pieces 31m is three. The number of the inner core pieces 31m and the length of the gap 31g (interval between the inner core pieces 31m) may be appropriately set so as to obtain desired magnetic characteristics.

  The inner core piece 31m is formed of a material containing a soft magnetic material. As the inner core piece 31m, for example, a compacted body obtained by compression molding a soft magnetic powder such as iron or an iron alloy (Fe-Si alloy, Fe-Ni alloy, etc.) or a coated soft magnetic powder further having an insulating coating, A composite material containing magnetic powder and resin can be used. In this example, the inner core piece 31m is a green compact.

(Outer core part)
As shown in FIG. 3, the outer core portion 32 is disposed at both ends of the inner core portion 31 and forms the annular magnetic core 3 together with the inner core portion 31. In this example, the outer core portion 32 is composed of one block-shaped core piece. That is, as shown in FIG. 3, the magnetic core 3 is composed of a plurality of core pieces including an inner core piece 31 m constituting the inner core portion 31 and a core piece constituting the outer core portion 32. The shape of the outer core portion 32 is not particularly limited. In this example, the outer core portion 32 has a dome shape in plan view (as viewed from the upper surface), and the inner end surface 32e is a flat surface. Moreover, the core piece which comprises the outer core part 32 is formed with the material containing a soft-magnetic material, and the above-mentioned compacting body, a composite material, etc. can be utilized. In this example, the outer core part 32 is a compacting body.

  As shown in FIG. 4, gaps 31 g are also provided between the inner core pieces 31 m located at both ends of the inner core portion 31 and the outer core portions 32, and filled with sealing resin 6 described later. Yes. The gap 31g between the inner core portion 31 and the outer core portion 32 may be a space (air gap) without being filled with the sealing resin 6.

(Insulation interposition member)
The reactor 1 (combination body 10) shown in this example includes an insulating interposed member 5 interposed between the coil 2 and the magnetic core 3, as shown in FIG. The insulating interposition member 5 is made of an electrically insulating material and has a function of ensuring electrical insulation between the coil 2 and the magnetic core 3.

  3 is interposed between the inner peripheral surface of the winding part 2c of the coil 2 and the outer peripheral surface of the inner core part 31, and positions the inner core part 31 in the winding part 2c. The insulation between the winding part 2c and the inner core part 31 is ensured. The insulating interposition member 5 is disposed on each inner core portion 31. In this example, the insulating interposition member 5 is composed of a pair of divided pieces 5A and 5B divided along the axial direction of the inner core portion 31. Hereinafter, the configuration of the insulating interposed member 5 (divided pieces 5A and 5B) will be described mainly with reference to FIG.

  The divided pieces 5A and 5B have a cross-sectional shape (a cross-sectional shape in a direction orthogonal to the axial direction of the inner core portion 31), and are sandwiched from the upper surface side and the lower surface side of the inner core portion 31 (inner core piece 31m). Are arranged as follows. Specifically, the divided pieces 5 </ b> A (5 </ b> B) are erected from the flat plate portion 51 disposed on the entire upper surface (lower surface) of the inner core portion 31 and both side edges of the flat plate portion 51. And a pair of side surface portions 52 disposed over a part of the side surface from the portion. The flat plate portion 51 and the side surface portion 52 are integrally formed. When the divided pieces 5A and 5B are arranged on the upper surface side and the lower surface side of the inner core portion 31, the edges of the side surface portions 52 do not contact each other, and a gap is formed therebetween. Therefore, the entire side surface of the inner core portion 31 is not covered with the side surface portion 52, and a part of the side surface (an intermediate portion in the vertical direction) is exposed.

  The split pieces 5A and 5B have a partition portion 53 that positions the inner core pieces 31m while maintaining a distance between the adjacent inner core pieces 31m. The partition part 53 protrudes from the inner surface of the side part 52 and is provided integrally. Further, the partition portions 53 positioned at both ends of the divided pieces 5A and 5B are arranged at both ends of the inner core portion 31 when the outer core portion 32 is disposed at both ends of the inner core portion 31 to constitute the magnetic core 3. The space | interval between each inner core piece 31m located and the both outer core parts 32 is hold | maintained. The thickness of the partition portion 53 (thickness along the axial direction of the inner core portion 31) corresponds to the thickness of the gap 31g (see FIG. 4). Therefore, since the divided pieces 5A and 5B have the partition portion 53, the inner core pieces 31m can be arranged at predetermined intervals, and between the inner core pieces 31m and the inner core portions 31 (inner core pieces 31). A gap corresponding to the thickness of the gap 31g can be formed between the outer core portion 32 and 31m).

  In addition, the divided pieces 5A and 5B are filled with unsolidified resin when filled with a sealing resin 6 described later, between the inner core pieces 31m, and between the inner core portion 31 and the outer core portion 32. A through hole 54 serving as a flow path for flowing into the formed gap is formed. In this example, a through hole 54 is formed in the flat plate portion 51, and the through hole 54 is provided at a position corresponding to a gap serving as a gap 31g (see FIG. 4).

  Examples of the material for forming the insulating interposition member 5 include polyphenylene sulfide (PPS) resin, polytetrafluoroethylene (PTFE) resin, liquid crystal polymer (LCP), polyamide (PA) resin such as nylon 6 and nylon 66, and polybutylene terephthalate. A thermoplastic resin such as (PBT) resin can be used. The insulating interposition member 5 can be produced by a known method such as injection molding.

(Case)
As shown in FIGS. 1, 2, and 4, the reactor 1 shown in this example includes a case 4 that houses the combined body 10 as a mounting member on which the combined body 10 is mounted. The case 4 has a bottom plate portion 40 on which the combined body 10 is placed and a side wall portion 41 erected from the bottom plate portion 40 so as to surround the combined body 10, and is opposite to the bottom plate portion 40 ( (Upper) is open. In this example, the shape of the side wall portion 41 is a rectangular frame shape. By storing the combined body 10 in the case 4, the combined body 10 can be protected from the external environment (dust, corrosion, etc.) or mechanically protected. In this example, the bottom surface of the bottom plate portion 40 of the case 4 is fixed so as to contact the upper surface of an installation target (not shown) such as a cooling base, and the reactor 1 is installed on the installation target. Although FIG. 1 shows an installation state in which the bottom plate portion 40 is downward, there may be an installation state in which the bottom plate portion 40 is upward or sideward. A cover (not shown) may be attached to the opening of the case 4.

  The case 4 shown in FIGS. 1 and 2 is a metal case in which a bottom plate portion 40 and a side wall portion 41 are integrally formed. In general, since metal has a relatively high thermal conductivity, if it is a metal case, the entire case can be used as a heat dissipation path, and the heat generated in the assembly 10 can be efficiently applied to an external installation target (for example, a cooling base). It can dissipate well. That is, the heat dissipation of the reactor 1 can be improved. Examples of the material for forming the case 4 include aluminum and its alloys, magnesium and its alloys, copper and its alloys, silver and its alloys, iron and steel, austenitic stainless steel, and the like. When formed of aluminum, magnesium, or an alloy thereof, the case 4 can be lightened.

(Sealing resin)
In the reactor 1 shown in this example, as shown in FIGS. 1 and 4, a sealing resin 6 that seals the combined body 10 is provided in the case 4. The sealing resin 6 is formed by storing the combination in the case 4 and then filling and solidifying the unsolidified sealing resin. In this example, the sealing resin 6 is filled in the case 4 so that substantially the entire assembly 10 excluding the winding end 2 e of the coil 2 is embedded in the sealing resin 6. By sealing the combination 10 with the sealing resin 6, it is possible to protect the combination 10 from electrical and mechanical protection and protection from the external environment.

  For the sealing resin 6, for example, an epoxy resin, a urethane resin, a silicone resin, an unsaturated polyester resin, a PPS resin, or the like can be suitably used. From the viewpoint of improving heat dissipation, a ceramic filler having high thermal conductivity such as alumina or silica may be mixed into the sealing resin 6.

  In this example, as shown in FIG. 4, when the sealing resin 6 is filled, the unsolidified resin is formed between the inner core pieces 31 m and between the inner core portion 31 and the outer core portion 32. The gap 31g is filled with sealing resin.

<Fixing structure of upper and lower surfaces of outer core>
In the reactor 1, the lower surface and the upper surface of the outer core portion 32 are fixed to the case 4 that is a mounting member. Hereinafter, the fixing structure of the outer core portion 32 will be described in detail mainly with reference to FIGS.

<Fixing structure of the lower surface of the outer core>
(Adhesive layer)
As shown in FIG. 4, the reactor 1 includes an adhesive layer 70 that bonds the lower surface of the outer core portion 32 and the bottom plate portion 40 between the lower surface of the outer core portion 32 and the bottom plate portion 40 of the case 4. The adhesive layer 70 fixes the lower surface of the outer core portion 32 to the bottom plate portion 40. In this example, the adhesive layer 70 is formed between the lower surface of the combined body 10 (the outer core portion 32 and the coil 2) and the bottom plate portion 40 of the case 4, and the lower surface of the coil 2 is also fixed to the bottom plate portion 40. ing. As a material for forming the adhesive layer 70, a resin (adhesive) having heat resistance to such an extent that it does not soften with respect to the maximum temperature achieved when the reactor is driven is preferable, and a resin having electrical insulation is more preferable. Specific examples include thermosetting resins such as epoxy resins, silicone resins and unsaturated polyesters, and thermoplastic fats such as PPS resins and LCPs. The adhesive layer 70 may be formed by applying an adhesive, for example, or may be an adhesive sheet in which an adhesive is applied on both sides of the base material. In this example, the adhesive layer 70 is formed of an epoxy adhesive.

<Fixing structure of the upper surface of the outer core>
(Fixture)
As shown in FIGS. 2 and 4, the reactor 1 includes a fixture that is disposed on the upper surface of the outer core portion 32 and fixes the upper surface of the outer core portion 32 to the case 4. In this example, a stay 80 is used as a fixture. The stay 80 is a band-like member, and is extended over the upper surface of the outer core portion 32 along the width direction (the direction in which the inner core portions 31 are arranged). It is attached to the attachment portion 45 with a screw 801. The upper surface of the outer core portion 32 is fixed to the case 4 via the stay 80 by the stay 80. The stay 80 may be formed of a metal such as aluminum or an alloy thereof, magnesium or an alloy thereof, copper or an alloy thereof, silver or an alloy thereof, iron, steel, or austenitic stainless steel.

  Furthermore, as shown in FIG. 5, an adhesive layer 71 that bonds the upper surface of the outer core portion 32 and the stay 80 may be provided between the upper surface of the outer core portion 32 and the stay 80. The upper surface of the outer core portion 32 is fixed to the stay 80 by the adhesive layer 71, and the upper surface of the outer core portion 32 can be firmly fixed to the case 4 via the stay 80.

  Instead of the stay 80, a plate spring that presses the upper surface of the outer core portion 32 downward (on the bottom plate portion 40 side of the case 4) may be used as the fixture. Similar to the stay 80, the leaf spring is disposed on the upper surface of the outer core portion 32, and both end portions may be attached to the case 4 with screws or the like. If it is a leaf | plate spring, the upper surface of an outer core part can be pressed below, and the upper surface of the outer core part 32 can be fixed to the case 4 more firmly.

<Estimation of natural frequency>
For the reactor having the same configuration as that of the first embodiment described above, the respective natural frequencies were calculated when only the lower surface of the outer core portion was fixed (fixed at one end) and when the upper and lower surfaces of the outer core portion were fixed (fixed at both ends). . Here, the natural frequency f _n (Hz) was calculated by the following equation (the subscript n represents the mode order). Moreover, the height (length in the vertical direction) of the outer core portion was changed, and the natural frequency in each case was estimated. The results are shown in Table 1.

ｋ_ｎ：係数
Ｅ：ヤング率（ＭＰａ）
Ｉ：断面二次モーメント（ｍｍ^４）
ρ：密度（ｋｇ／ｍｍ^３）
Ａ：断面積（ｍｍ^２）
Ｌ：外側コア部の高さ（ｍｍ） [Formula 1]

k _n : coefficient E: Young's modulus (MPa)
I: Sectional moment of inertia (mm ⁴ )
ρ: Density (kg / mm ³ )
A: Cross-sectional area (mm ² )
L: Height of outer core part (mm)

The value of k _n is different in the cases of one end fixed and fixed-fixed, where treats primary mode n = 1, the case of one end fixed 1.875, the case of the both ends fixed to the [pi. E, I, ρ, and A were set as follows.
E = 40000 (MPa)
I = 13500 (mm ⁴ )
ρ = 7.2 × 10 ⁻⁶ (kg / mm ³ )
A = 720 (mm ² )

  From the results of Table 1, it can be seen that the upper and lower surfaces of the outer core portion are fixed, so that the natural frequency is higher than when only the lower surface is fixed. Here, in the reactor utilized for the power converter device mounted in a hybrid vehicle, an electric vehicle, etc., the height of an outer core part is designed in 24 mm or more and 40 mm or less in many cases. As can be seen from Table 1, in this trial calculation example, when both ends are fixed, the natural frequency can be over 10 kHz when the height of the outer core portion is 40 mm or less, and further 11 kHz or more can be achieved at 38 mm or less. On the other hand, in the case of one-end fixation, when the height of the outer core portion is 24 mm or more and 40 mm or less, the natural frequency is less than 10 kHz, and cannot exceed 10 kHz.

<Effect>
The reactor 1 of Embodiment 1 has the following effects.

  (1) Since both the lower surface and the upper surface of the outer core portion 32 are fixed to the mounting member (case 4), the natural frequency of the reactor is increased, and the natural frequency can be shifted to the high frequency side. it can. As a result, it is possible to make the natural frequency of the reactor higher than the drive frequency (5 kHz to 10 kHz). For example, the natural frequency is more than 10 kHz, and more than 11 kHz. Therefore, the natural frequency of the reactor can be out of the drive frequency band, and resonance between the natural frequency and the drive frequency can be avoided. Therefore, the resonance phenomenon between the natural frequency and the drive frequency can be avoided, the vibration during the reactor driving can be suppressed, and the noise due to the vibration can be reduced.

[Modification 1]
In Embodiment 1 described above, the case where the placement member is the case 4 (see FIG. 2) has been described as an example, but the placement member may be a flat plate-like member. In this case, the lower surface of an outer core part and the flat plate of a mounting member are adhere | attached with an adhesive layer, and the lower surface of an outer core part is fixed to a flat plate. On the other hand, it is possible to fix the upper surface of the outer core portion to the flat plate by arranging the stay (plate spring) of the fixture on the upper surface of the outer core portion and attaching the stay to the flat plate. The flat member used for the mounting member may be formed of a metal such as aluminum or an alloy thereof in the same manner as the case 4. In this case, at least a part of the combination may be covered with a mold resin. As the mold resin, an epoxy resin, a PPS resin, a PA resin, or the like can be suitably used. When the assembly is integrated with the mold resin, the gap 31g (see FIG. 4) may be filled with the mold resin.

[Modification 2]
In the first embodiment described above, the case where the gap 31g is filled with the sealing resin 6 is described as an example as shown in FIG. 4, but the gap 31g may be an air gap. In the first embodiment, the insulating interposed member 5 (divided pieces 5A and 5B) shown in FIG. 3 is used, and the flow path of the resin is secured by the through hole 54 while the interval between the core pieces is held by the partition 53. . In the case of an air gap, for example, the insulating interposition member 5 may be formed in a cylindrical shape so that the gap 31g is not filled with resin. Specifically, in the divided pieces 5A and 5B, when the side surface portion 52 is extended and the divided pieces 5A and 5B are arranged on the upper surface side and the lower surface side of the inner core portion 31, the edges of the respective side surface portions 52 Are made in contact with each other, and the through-hole 54 serving as a resin flow path is not formed. Thereby, when the sealing resin 6 is filled, unsolidified resin is prevented from flowing into the gap 31g, and an air gap can be formed between the core pieces.

[Embodiment 2]
The reactor of Embodiment 2 is demonstrated with reference to FIG. 6, FIG. The reactor according to the second embodiment includes a protruding portion 46 that protrudes from the inner surface of the side wall portion 41 and contacts the inner end surface 32e of the outer core portion 32 that faces the inner core portion 31 in the case 4 that is a mounting member. The point is mainly different from the first embodiment. In the following description, differences from the above-described first embodiment will be mainly described, and a redundant description of the same configuration as that of the first embodiment will be omitted.

  6 and 7 are integrally formed on the inner surface of the side wall 41 of the case 4 along the height direction (vertical direction). In the reactor 1 </ b> A shown in FIG. 6, the protruding portion 46 protruding from the inner surface of the side wall portion 41 enters between the inner core portion 31 and the outer core portion 32 and is in contact with the inner end surface of the outer core portion 32. . On the other hand, in the reactor 1B shown in FIG. 7, the outer core portion 32 is expanded in the width direction (the direction in which the inner core portions 31 are arranged), and both side edges of the inner end surface 32e of the outer core portion 32 are in the width direction of the inner core portion 31. It is located outside the outer side surface. In the reactor 1 </ b> B, the protrusion 46 does not enter between the inner core portion 31 and the outer core portion 32, and is in contact with the inner end surface of the outer core portion 32.

  In any of the reactors 1A and 1B shown in FIGS. 6 and 7, the outer core portion 32 is supported by the protruding portion 46 because the protruding portion 46 contacts the inner end surface 32 e of the outer core portion 32. Therefore, it can suppress that the outer core part 32 inclines or moves to the inner core part 31 side by electromagnetic attraction. Therefore, compared with the reactor 1 of Embodiment 1, the vibration of the outer core part 32 by electromagnetic attraction force can be suppressed more. Therefore, the vibration of the outer core part 32 at the time of a reactor drive can be suppressed effectively, and the noise by vibration can be reduced more.

  In the case of the reactor 1 </ b> A shown in FIG. 6, a protrusion 46 provided integrally with the metal case 4 enters between the inner core portion 31 and the outer core portion 32. Since the protrusion 46 is in the middle of the magnetic path formed in the magnetic core 3 when the coil 2 is energized, the loss may increase. On the other hand, in the case of the reactor 1B shown in FIG. 7, the protrusion 46 does not enter between the inner core portion 31 and the outer core portion 32, and the protrusion 46 does not exist in the middle of the magnetic path. Loss does not increase.

  The reactor of the present invention includes various converters such as an in-vehicle converter (typically a DC-DC converter) and an air conditioner converter mounted on a vehicle such as a hybrid vehicle, a plug-in hybrid vehicle, an electric vehicle, and a fuel cell vehicle. It can be used as a component of a power conversion device.

1, 1A, 1B Reactor 10 Combination 2 Coil 2c Winding part 2r Connection part 2e Winding end part 3 Magnetic core 31 Inner core part 31m Inner core piece 31g Gap 32 Outer core part 32e Inner end face 4 Case (mounting member)
40 Bottom plate portion 41 Side wall portion 45 Stay mounting portion 46 Projection portion 5 Insulating interposition member 5A, 5B Split piece 51 Flat plate portion 52 Side surface portion 53 Partition portion 54 Through hole (flow path)
6 Sealing resin 70 Adhesive layer 71 Adhesive layer 80 Stay (fixing tool) 801 Screw

Claims (5)

A coil having a winding part;
A magnetic core having an inner core portion arranged inside the winding portion and an outer core portion arranged outside the winding portion;
A reactor comprising a mounting member on which a combination of the coil and the magnetic core is mounted,
The magnetic core has a plurality of core pieces and a gap provided between the core pieces,
The outer core portion has a lower surface placed on the mounting member and an upper surface on the opposite side,
A reactor in which a lower surface and an upper surface of the outer core part are respectively fixed to the mounting member.   The reactor according to claim 1, wherein a natural frequency of the reactor is higher than a driving frequency and exceeds 10 kHz. The mounting member is a case having a bottom plate portion on which the combined body is mounted and a side wall portion surrounding the periphery of the combined body;
A sealing resin that fills the case and seals the assembly;
The reactor according to claim 1, wherein the gap is filled with the sealing resin. An adhesive layer that adheres the lower surface of the outer core portion and the mounting member;
The reactor according to any one of claims 1 to 3, further comprising: a fixture that is disposed on an upper surface of the outer core portion and fixes the upper surface of the outer core portion to the mounting member. The mounting member is a case having a bottom plate portion on which the combined body is mounted and a side wall portion surrounding the periphery of the combined body;
The magnetic core is an annular magnetic core having a pair of inner core portions and a pair of outer core portions disposed at both ends of the inner core portions,
The said case has a projection part which protrudes from the inner surface of the said side wall part, and has a projection part which contacts the inner end surface facing the said inner core part of the said outer core part. Reactor.

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