JP2020021859A - Reactor - Google Patents

Abstract

To provide a reactor capable of easily positioning a bobbin and improving workability in a process of assembling the bobbin with respect to a core.SOLUTION: A side portion 54 has a positioning groove 64 extending from an opening part 58 to a bottom part 52 side on the inner peripheral surface 54s, and a bobbin 30 has a body part 32 around which a coil 20 is wound, and a flange portion 34 extending in the radiation direction from the end of the body part 32 around the axis A, and the flange portion 34 has a protruding portion 38 located radially outside the outer peripheral surface 20s of the coil 20 and inserted into the positioning groove 64.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a reactor including a coil, a bobbin around which the coil is wound, a core that houses the coil and the bobbin, and a potting material that is filled inside the core.

  A vehicle driven by an electric motor has a power control unit (PCU) for controlling electric power of a battery, and the PCU has a DC-DC converter. The DC-DC converter may be provided with a reactor.

  Patent Literature 1 discloses a reactor in which a coil (coil winding) wound around a bobbin (support) is housed inside a core (ferrite base), and further filled with a potting material (resin). In this reactor, a recess is provided on the bottom (base) of the core, and a protrusion is provided on the flange (lower flange) of the bobbin. Good positional relationship is maintained.

JP 2008-91197 A

  In the reactor disclosed in Patent Literature 1, when the bobbin is housed inside the core, the concave portion and the projection located inside the core become blind spots. For this reason, it is difficult to position the bobbin by inserting the protrusion into the recess, and the process of assembling the bobbin to the core becomes complicated.

  The present invention has been made in consideration of such problems, and has as its object to provide a reactor that facilitates positioning of a bobbin and improves workability in a process of assembling the bobbin with respect to a core. .

The present invention
Coils and
A bobbin around which the coil is wound;
A core accommodating the coil and the bobbin therein;
And a potting material to be filled into the core,
The core has a first core located on one side in the axial direction, and a second core located on the other side in the axial direction,
At least one of the first core and the second core has a bottom located at one end of the core, a side extending axially from a periphery of the bottom, and an opening located at an end of the side. And having
The side portion has a positioning groove extending from the opening to the bottom side on an inner peripheral surface,
The bobbin has a trunk on which the coil is wound, and a flange extending radially from an end of the trunk about an axis,
The flange has a protruding portion that is located outside the outer circumferential surface of the coil in the radial direction and that is inserted into the positioning groove.

  ADVANTAGE OF THE INVENTION According to this invention, positioning of a bobbin becomes easy and workability | operativity of the assembly | attachment process of a bobbin with respect to a core improves.

FIG. 1 is a perspective view of the reactor according to the present embodiment. FIG. 2 is a sectional view taken along line II-II of FIG. FIG. 3 is a sectional view taken along line III-III of FIG.

  BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a reactor according to the present invention will be described in detail with reference to the accompanying drawings, showing preferred embodiments.

[1. Configuration of reactor 10]
As shown in FIGS. 1 to 3, the reactor 10 according to the present embodiment includes a coil 20, a bobbin 30 around which the coil 20 is wound, a core 50 accommodating the coil 20 and the bobbin 30 therein, and a core 50. And a potting material 70 filled therein. The central axes of the coil 20, the bobbin 30, and the core 50 coincide with each other, and this becomes the reactor 10 and the central axis (hereinafter, referred to as the axis A).

  The coil 20 is formed into a cylindrical shape around the axis A by winding the electric wire around the bobbin 30 (the body portion 32) in the circumferential direction. The electric wire may be any of a round wire, a square wire, and a flat wire. From the coil 20, a coil terminal 22a formed at one end of the electric wire and a coil terminal 22b formed at the other end of the electric wire are drawn out. The coil terminal 22a is drawn out of the core 50 from a drawing hole 60a described later. The coil terminal 22b is drawn out of the core 50 from a drawing hole 60b described later.

  The bobbin 30 is formed of, for example, polyphenylene sulfide (PPS) resin. The thermal conductivity of the PPS resin is about 0.3 W / m · K. The bobbin 30 has a body 32 and two flanges 34. The body 32 has a cylindrical shape around the axis A, and the coil 20 is wound around the outer peripheral surface. A flange portion 34 is formed on one and the other of the body portion 32 in the axial direction. The flange 34 extends in a radial direction about the axis A. As shown in FIG. 3, the flange portion 34 of the present embodiment has a plurality of band members 36 extending in different directions, and in the present embodiment, four band members 36. Each band member 36 is, for example, rectangular. The plurality of belt-shaped members 36 are arranged at equal intervals along the circumferential direction with respect to the trunk 32, and at 90 ° intervals in the present embodiment. Each band-shaped member 36 has a protruding portion 38 at the distal end in the radial direction. The protrusion 38 will be described in [2] below.

  The core 50 is formed of a magnetic material, for example, ferrite. As shown in FIG. 2, the core 50 has a first core 50a located on one side in the axial direction and a second core 50b located on the other side in the axial direction. Since the first core 50a and the second core 50b of the present embodiment have the same shape, the first core 50a will be mainly described here. The first core 50a has a bottom 52, a side 54, a center 56, and an opening 58. The bottom part 52 is located at one end of the first core 50a in the axial direction. The bottom part 52 has an inner bottom surface 62 facing the inside of the first core 50a. The side portion 54 has a cylindrical shape extending along the axial direction from the periphery of the bottom portion 52, and surrounds the coil 20. The side portion 54 has a plurality of positioning grooves 64 extending from the opening 58 toward the bottom portion 52 on the inner peripheral surface 54s. The positioning groove 64 will be described in [2] below. The center portion 56 has a cylindrical shape extending along the axial direction from the center of the bottom portion 52, and is inserted through the body portion 32 of the bobbin 30. The opening 58 is a circular opening located at one end in the axial direction of the first core 50a. The first core 50a and the second core 50b have their bottoms 52 facing outward in the axial direction, and their ends on the opening 58 side are in contact with each other.

  As shown in FIG. 1, the side portion 54 of the first core 50a has a part of the lead holes 60a and 60b penetrating from the inner peripheral side to the outer peripheral side and opening to the second core 50b side. Similarly, the side portion 54 of the second core 50b has a part of the lead holes 60a and 60b penetrating from the inner peripheral side to the outer peripheral side and opening to the first core 50a side. In a state where the first core 50a and the second core 50b are combined, a part of the drawing hole 60a of the first core 50a and a part of the drawing hole 60a of the second core 50b are combined to form one drawing hole. 60a is formed. Similarly, in a state where the first core 50a and the second core 50b are combined, a part of the extraction hole 60b of the first core 50a and a part of the extraction hole 60b of the second core 50b are combined, and 1 One extraction hole 60b is formed. The lead holes 60a and 60b guide the coil terminals 22a and 22b from the inside of the core 50 to the outside. The extraction hole 60a is located closer to the bottom 52 of the first core 50a than the extraction hole 60b, and the extraction hole 60b is located closer to the bottom 52 of the second core 50b than the extraction hole 60a. Further, the extraction hole 60a and the extraction hole 60b are formed at different positions in the circumferential direction of the core 50 within a range of less than 180 ° around the axis A. Note that the lead hole 60a may be provided only in the first core 50a, and the lead hole 60b may be provided only in the second core 50b.

  The potting material 70 is formed of a member having a higher thermal conductivity than the material of the bobbin 30. For example, it is formed of a high thermal conductive epoxy resin in which a metal filler or the like is mixed into an epoxy resin. By mixing a metal filler such as alumina into the epoxy resin, the thermal conductivity of the epoxy resin can be increased to about 2.0 W / m · K. The potting material 70 fills the space inside the core 50, that is, the gap where the coil 20 and the bobbin 30 do not exist. For example, between the outer peripheral surface 20s of the coil 20 and the inner peripheral surface 54s of the side portion 54, between the inner peripheral surface of the body portion 32 and the outer peripheral surface of the central portion 56, a gap 68 described in the following [2], and the like. Is filled.

[2. Projecting portion 38 and positioning groove 64]
The protrusion 38 of the flange 34 will be described with reference to FIGS. Each projecting portion 38 is located radially outside the outer peripheral surface 20 s of the coil 20. If the length from the axis A to the tip of the protrusion 38 is rf, and the length from the axis A to the outer peripheral surface 20s of the coil 20 is rc, rf> rc. The protrusion 38 is inserted into the positioning groove 64 of the core 50. It is not necessary that all the band members 36 have the protruding portions 38, and it is sufficient that at least one band member 36 has the protruding portions 38.

  The positioning groove 64 of the side portion 54 will be described with reference to FIGS. The positioning groove 64 is formed so as to be parallel to the axis A from the opening 58 to the bottom 52 side. Further, the plurality of positioning grooves 64 are arranged at equal intervals along the inner circumferential direction of the side portion 54, and at 90 ° intervals in the present embodiment. Here, assuming a plane orthogonal to the axis A (for example, the paper surface of FIG. 3), the width of the positioning groove 64 in that plane is larger than the width of the protrusion 38. The positioning groove 64 of the present embodiment has a step 66 at the opening 58 side of the bottom 52, more specifically, at an end position on the bottom 52 side. The height of the step 66 can be set arbitrarily. The step portion 66 has a flat surface on the opening 58 side, and the flat surface contacts the protruding portion 38. That is, since the step portion 66 is interposed between the bottom portion 52 and the projecting portion 38 and functions as a spacer, a gap 68 is formed between the flange portion 34 (the band-shaped member 36) and the bottom portion 52. As described above, the space 68 is filled with the potting material 70.

[3. Manufacturing method of reactor 10]
An electric wire is wound around the body 32 of the bobbin 30 to form the coil 20. At this time, the coil terminals 22a and 22b are pulled out in a predetermined direction. Next, the bobbin 30 is placed inside the first core 50a. At this time, the positioning of the positioning groove 64 and the protrusion 38 is performed at the opening 58 of the first core 50a. After the alignment, the protrusion 38 is slid along the positioning groove 64 to bring the bobbin 30 and the bottom 52 of the first core 50a closer to each other. When the protruding portion 38 and the step portion 66 come into contact with each other, the bobbin 30 is placed at a predetermined position inside the first core 50a. Further, the coil terminal 22a is pulled out from the lead hole 60a of the first core 50a. Next, the second core 50b is put on the first core 50a containing the bobbin 30. At this time, the positioning of the positioning groove 64 and the projecting portion 38 is performed at the opening 58 of the second core 50b. After the alignment, the protrusion 38 is slid along the positioning groove 64 to bring the bobbin 30 and the bottom 52 of the second core 50b closer to each other. Further, the coil terminal 22b is pulled out from the lead hole 60b of the second core 50b.

  Next, the first core 50a and the second core 50b are fixed with a jig or the like, and the liquid potting material 70 is injected into the core 50 from one or both of the one or both of the drawing holes 60a and 60b. The potting material 70 penetrates into a gap inside the core 50 including the gap 68. Next, heat is applied to the core 50. Then, the potting material 70 is cured, and the first core 50a and the second core 50b are bonded by the potting material 70. Thus, the reactor 10 in which the coil 20, the bobbin 30, the core 50, and the potting material 70 are integrated is obtained.

[4. Modification]
The positions of the protrusion 38 and the positioning groove 64 can be freely set. That is, the belt-shaped members 36 having the protruding portions 38 do not have to be arranged at regular intervals along the circumferential direction of the body portion 32, and similarly, the positioning grooves 64 are formed along the inner peripheral surface 54 s of the side portions 54. They need not be arranged at equal intervals. However, the position of the band member 36 and the position of the positioning groove 64 need to correspond to each other.

  The number and size of the protrusions 38 and the positioning grooves 64 can be freely set. Further, the positioning groove 64 may not be parallel to the axis A.

  In the present embodiment, the step 66 as a spacer is provided at the end of the positioning groove 64, but the step 66 may not be provided in the positioning groove 64. In this case, a space 68 can be formed by providing a spacer at any position on the inner bottom surface 62.

  In the present embodiment, the first core 50a and the second core 50b have the same shape. However, if the core 50 has a cylindrical shape, the first core 50a and the second core 50b do not have to have the same shape. For example, the second core 50b may be a flat plate that closes the first core 50a. Further, instead of the core 50 being composed of two core members (the first core 50a and the second core 50b), the core 50 may be composed of three or more core members.

[5. Invention obtained from the embodiment]
The invention that can be grasped from the above embodiment and modifications will be described below.

The present invention
A coil 20;
A bobbin 30 around which the coil 20 is wound;
A core 50 that houses the coil 20 and the bobbin 30 therein;
A potting material 70 filled in the core 50, the reactor 10 comprising:
The core 50 has a first core 50a located on one side in the axial direction, and a second core 50b located on the other side in the axial direction,
At least one of the first core 50a and the second core 50b is located at one end of the core 50, a side portion 54 extending along the axial direction from the periphery of the bottom portion 52, and an end of the side portion 54. An opening 58;
The side portion 54 has a positioning groove 64 extending from the opening portion 58 to the bottom portion 52 side on the inner peripheral surface 54s,
The bobbin 30 includes a body portion 32 around which the coil 20 is wound, and a flange portion 34 extending radially from the end of the body portion 32 around the axis A,
The flange portion 34 has a protruding portion 38 that is located radially outside the outer peripheral surface 20 s of the coil 20 and that is inserted into the positioning groove 64.

  According to the above configuration, the bobbin 30 is positioned by positioning the positioning groove 64 and the projection 38 at the opening 58 of the core 50 (at least one of the first core 50a and the second core 50b). At this time, since the visibility of the positioning groove 64 and the protruding portion 38 is good, the positioning of the bobbin 30 is facilitated, and the workability in the process of assembling the bobbin 30 to the core 50 is improved.

In the present invention,
The positioning groove 64 has a step 66 on the opening 58 side of the bottom 52,
The gap 68 may be formed between the bottom 52 and the bobbin 30 by interposing the step 66 between the bottom 52 and the protruding section 38, and the potting material 70 may be filled in the gap 68.

  According to the above configuration, the gap 68 between the bottom 52 and the bobbin 30 is filled with the potting material 70, so that the heat of the coil 20 can be efficiently transferred to the core 50.

  In addition, the reactor according to the present invention is not limited to the above-described embodiment, but may adopt various configurations without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Reactor 20 ... Coil 20s ... Outer peripheral surface 30 ... Bobbin 32 ... Body part 34 ... Flange part 38 ... Projecting part 50 ... Core 50a ... First core 50b ... Second core 52 ... Bottom part 54 ... Side part 54s ... Inner peripheral surface 58 ... opening 64 ... positioning groove 66 ... step 68 ... void 70 ... potting material

Claims (2)

Coils and
A bobbin around which the coil is wound;
A core accommodating the coil and the bobbin therein;
And a potting material to be filled into the core,
The core has a first core located on one side in the axial direction, and a second core located on the other side in the axial direction,
At least one of the first core and the second core has a bottom located at one end of the core, a side extending axially from a periphery of the bottom, and an opening located at an end of the side. And having
The side portion has a positioning groove extending from the opening to the bottom side on an inner peripheral surface,
The bobbin has a trunk on which the coil is wound, and a flange extending radially from an end of the trunk about an axis,
The reactor, wherein the flange portion is located outside of the outer peripheral surface of the coil in the radial direction and has a protruding portion that is inserted into the positioning groove. The reactor according to claim 1,
The positioning groove has a step on the opening side than the bottom,
A reactor in which the step portion is interposed between the bottom portion and the protruding portion to form a space between the bottom portion and the bobbin, and the space is filled with the potting material.

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