JP6518552B2 - Coil device - Google Patents

Description

  The present invention relates to a coil device that can be suitably used, for example, in applications such as automotive choke coils.

  For example, a coil device shown in Patent Document 1 below is known as a surface mount type choke coil. As shown in Patent Document 1, there is known a coil device in which a rectangular conductor is wound in an edgewise winding inside a pot core.

  However, in such a conventional coil device, it is difficult to simultaneously secure the DC bias characteristics and the high inductance. Further, in the conventional coil device, the flat conductor is wound in a single layer in an edgewise winding. For this reason, it is necessary to locate one of the lead portions of the rectangular conductor constituting the coil portion at the bottom of the pot core, and to draw the lead portion therefrom. Therefore, extra space is required for lead-out, and it is difficult to realize a small-sized, high-inductance coil device.

Japanese Patent Application Laid-Open No. 11-307357

  The present invention has been made in view of such an actual situation, and an object thereof is to provide a coil device which can simultaneously ensure DC bias characteristics and high inductance and which is easy to miniaturize.

In order to achieve the above object, a coil device according to the present invention is:
And the center part,
A pot core having side wall portions surrounding the periphery of the center core portion at a predetermined interval;
A coil portion disposed between the center core portion and the side wall portion;
A coil device comprising: a lid core covering an upper portion of the coil portion and an upper portion of the center portion;
The coil portion is configured by edgewise winding a wire having a flat cross section in two or more layers,
A pair of lead portions, which are both end portions of the wire, are drawn out from the upper end of the side wall portion.

  In the coil device according to the present invention, the coil portion is configured by edgewise winding of a wire having a flat cross section into two or more layers and even layers. Therefore, a pair of lead parts which are both ends of the wire are both located at the upper end of the coil part, and easily from the upper end of the side wall of the pot core to the outside without requiring an extra space inside the pot core. It can be pulled out. Therefore, the inductance of the coil system can be increased, and the size and height of the coil system can be reduced.

  Furthermore, since there is no need for an extra space for lead portion extraction inside the pot core, the distance between the outer periphery of the coil portion and the side wall portion of the pot core is kept constant, and the lid core and The gap with the side wall of the pot core can be easily adjusted to a constant gap. For this reason, the control of the gap between the parts constituting the core is easy, the magnetic saturation is improved, and the DC bias characteristics are improved.

  Preferably, the bottom of the core portion is fixed to the bottom plate portion of the pot core in a state where the coil portion is attached to the outer periphery of the core portion. That is, the coil portion is not attached to the inside of the pot core as an air core coil, but is disposed inside the pot core in a state of being wound around the core portion, so the distance between the core portion and the coil portion is Thus, the DC bias characteristics can be improved.

  The bottom of the center core may be fixed to the bottom plate of the pot core by an adhesive. Alternatively, the bottom of the center core may be fixed to the bottom plate of the pot core by a magnetic substance-containing resin. By configuring in this way, the gap between the core and the pot core is adjusted, the adjustment of the characteristics becomes easy, and the degree of freedom in design is improved. Moreover, it is also easy to improve an inductance by adhering the bottom part of a core part to the bottom plate part of a pot core using magnetic body containing resin.

  The magnetic properties of the core portion and the magnetic properties of the pot core may be made different. For example, by selecting a combination of magnetic materials such that the permeability μ of the pot core is higher than the permeability μ of the middle core and the saturation magnetic flux density Bs of the middle core is higher than the saturation magnetic flux density Bs of the pot core, DC superposition characteristics can be improved.

  For example, it is preferable that the pot core is formed of a magnetic body made of a sintered metal and the core portion is made of a magnetic body made of a powder compact of iron-based metal powder and a resin. The lid core is preferably made of the same magnetic material as the pot core.

  The bottom portion of the center core portion may be formed integrally with the bottom plate portion of the pot core. In that case, an air core coil is disposed around the center core.

  Preferably, a pair of the lead portions of the wire is drawn to the outside of the side wall portion near the upper end of the coil portion, and the upper end of the side wall portion has a lead groove for drawing the lead portion outward. Each is formed. By forming the lead grooves, it becomes easy to form a uniform gap along the circumferential direction between the outer periphery of the lid core and the side wall portion of the pot core, and the DC bias characteristics are improved.

  Preferably, a pair of the lead portions of the wire is drawn to the outside of the side wall portion at a predetermined angle of 20 degrees to 60 degrees, and is connected to a pair of terminals attached to the outer surface of the side wall portion Yes. With such a configuration, the wire of the flat cross section is easy to be edge-wound in two layers around the center core portion, and it is also easy to secure insulation between the pair of terminals.

Preferably, the terminal is
A terminal body attached to an outer peripheral surface of the side wall portion;
A lower locking piece formed at the lower end portion of the terminal body and locked to the lower end surface of the side wall portion;
An upper locking piece formed at an upper end portion of the terminal body and locked to an upper end surface of the side wall portion;
An installation piece disposed outside the lead groove;
It has the connection piece which connects the said installation piece and the said terminal main body integrally.

  Having such a terminal facilitates downsizing of the coil device, and facilitates electrical connection and mechanical connection between the lead portion and the terminal. These connections are made, for example, by laser welding or spot welding.

FIG. 1 is an overall perspective view of a coil device according to an embodiment of the present invention. FIG. 2A is an exploded perspective view of the coil device shown in FIG. FIG. 2B is a bottom view of the coil portion wound directly around the core shown in FIG. 2A. FIG. 2C is a perspective view of the pot core shown in FIG. 2A as viewed from the lower side in the Z-axis direction. FIG. 2D is a perspective view showing a modified example of the terminal shown in FIG. 2A. FIG. 3A is a schematic cross-sectional view taken along the line III-III shown in FIG. FIG. 3B is a schematic cross-sectional view of a coil device according to another embodiment of the present invention. FIG. 3C is a schematic cross-sectional view of a coil device according to still another embodiment of the present invention. FIG. 4 is an exploded perspective view of the coil device shown in FIG. 3C. FIG. 5A and FIG. 5B are cross-sectional views showing examples of the cross section of the wire.

  Hereinafter, the present invention will be described based on embodiments shown in the drawings.

First Embodiment As shown in FIG. 1, a coil device 2 according to the present embodiment is used as an on-vehicle choke coil for idling stop, fuel pump, etc., for example, and a pot core 10 and a lid core 30 It has terminals 40a and 40b.

  As shown to FIG. 2A and FIG. 3A, the pot core 10 has the circular-shaped bottom plate part 11, and the side wall part 14 which stands up in the Z-axis direction from the outer peripheral part of the bottom plate part 11. As shown in FIG. A cylindrical recess 18 is formed inside the pot core 10 by the bottom plate portion 11 and the side wall portion.

  A cylindrical core 12 is disposed inside the recess 18 of the pot core 10, and the bottom of the core 12 is substantially centered on the bottom plate 11 of the pot core 10 with a second adhesive 52 or the like. It is fixed. The core portion 12 has an axial center in the Z-axis direction, and the coil portion 20 is disposed on the outer periphery of the core portion 12.

  As shown in FIGS. 2A and 2B, the coil portion 20 is configured by edgewise winding a wire 22 having a flat cross section into two or more layers, and is wound directly around the outer periphery of the core portion 12. The wire 22 may be a conductor having a flat cross section in which the width w is larger than the thickness t, as shown in FIGS. 5A and 5B, and the cross sectional shape may be rectangular or elliptical. It may be a shape.

  The aspect ratio t / w is preferably 0.05 to 0.9, more preferably 0.5 to 0.8. A flat wire is exemplified as the wire 22 having a representative flat cross section. The area around the wire 22 is covered with an insulating film 24.

  The edgewise winding is a method of winding longitudinally with the short side (thickness t side) of the wire 22 having a flat cross section as the inner diameter surface. As shown in FIGS. 2A and 2B, the wire 22 is edgewise wound in two or more layers around the outer periphery of the core portion 12. When edgewise winding in two or more layers around the center core 12, the recesses 13a and 13b formed on both end surfaces of the center core 12 in the Z-axis direction serve as fixing parts and the like.

  In the present embodiment, the coil portion 20 is pre-coiled with two or more even layers on the outer peripheral portion of the core portion 12 so that the pair of lead portions 22a and 22b are drawn out in the upper part in the Z-axis direction. It is wound in a shape. The lead portions 22 a and 22 b constitute both ends of the wire 22. Moreover, as the wire 22, it may be comprised by a single wire, or may be comprised by a strand wire, and it is preferable to be comprised by an insulation coating conducting wire.

  The inner peripheral surface of the side wall portion 14 is a cylindrical outer peripheral surface, the outer peripheral surface is a prismatic outer peripheral surface, and in the present embodiment, the outer peripheral surface of the side wall portion 14 is at two adjacent corner portions of the quadrangular prism. A chamfered outer peripheral surface 14b is formed, and the outer peripheral surface of a hexagonal prism as a whole is formed. The upper end 14a of the side wall portion 14 in the Z-axis direction is positioned higher in the Z-axis direction than the upper end 12a of the center core portion 12 in the Z-axis direction, as shown in FIG. 3A. In the drawing, the Z-axis is a direction coinciding with the axial center of the center core portion 12 of the pot core 10, and also coincides with the winding axis of the coil portion 20. Further, axes perpendicular to each other with respect to the Z-axis are taken as an X-axis and a Y-axis, and the terminal 40a and the terminal 40b are disposed to face each other in the X-axis direction.

  As shown in FIG. 2A, the pair of terminals 40a and 40b respectively have flat plate-like terminal bodies 41a and 41b in close contact with the opposing outer peripheral surface 14c of the side wall portion 14 along the Z-axis direction. At lower ends in the Z-axis direction of the terminal main bodies 41a and 41b, lower locking pieces 42a and 42b are formed integrally with the main bodies 41a and 41b so as to be in close contact with the lower surface of the side wall portion 14. The lower locking pieces 42a and 42b are set to have a length such that they do not contact each other on the lower surface of the bottom plate portion 11 to cause a short circuit.

  On the inner surface of each lower locking piece 42a, 42b, among the three locking recesses 15a, 15b, 15c (see FIG. 2C) formed along the Y-axis direction respectively formed in the lower end face of the corresponding side wall portion 14 Two locking projections 16a and 16c are formed to fit in the two outer recesses 15a and 15c. As shown in FIG. 2C, the locking recesses 15a, 15b, 15c may be formed on the surface 10b which is further recessed than the outer bottom surface 10a of the pot core 10. The surface 10b has a shape matched to the shape of the lower locking pieces 42a and 42b shown in FIG. 2A.

  The upper locking pieces 43a and 43b are formed integrally with the main bodies 41a and 41b at the upper end in the Z-axis direction of the terminal main bodies 41a and 41b so that the upper locking pieces 43a and 43b are in close contact is there. The upper locking pieces 43a and 43b are set to have a length that prevents mutual contact and short circuit.

  Locking convex portions 19a and 19b are formed on the inner surface of each of the upper locking pieces 43a and 43b, and the locking convex portions 19a and 19b are stepped surfaces one step lower than the upper end 14a of the side wall portion 14 shown in FIG. 2A. It is adapted to be fitted into locking recesses 17a and 17b formed in 14a1. The upper surfaces of the upper locking pieces 43a and 43b attached to the step surface 14a1 are substantially flush with the upper end 14a of the side wall portion 14.

  In the middle of the terminal main bodies 41a and 41b in the Z-axis direction, connection pieces 44a and 44b respectively projecting toward the chamfered outer peripheral surface 14b are integrally formed with the main bodies 41a and 41b. Installation pieces 46a and 46b substantially perpendicular to the Z-axis are formed on the top end portions of the connection pieces 44a and 44b. The upper surfaces of the installation pieces 46a and 46b are designed to be substantially flush with the bottom surfaces of the notched grooves (lead grooves) 14d and 14e formed on the upper portions of the respective chamfered outer peripheral surfaces 14b. .

  Leads 22a and 22b protruding outward from the notched grooves 14d and 14e are installed on the upper surfaces of the installation pieces 46a and 46b, and the installation pieces 46a and 46b are electrically connected to the leads 22a and 22b. Ru. The tip portions of the lead portions 22a and 22b are joined to the installation pieces 46a and 46b by solder welding, laser welding, arc welding or the like. In the drawings, the end portions of the lead portions 22a and 22b are connected to the installation pieces 46a and 46b by laser welding, respectively, and are drawn as if weld balls are formed.

  As shown in FIG. 3A, although the inner bottom surface 18a of the recess 18 is also the upper surface of the bottom plate portion 11, the lower surface 12b of the core portion 12 and the lower surface of the coil portion 20 can be easily adhered via the second adhesive 52. Flat surface. The adhesive 52 also penetrates into the recess 13 b of the core 12 to strengthen the bond between the core 12 and the pot core 10. The height H3 from the inner bottom surface 18a of the pot core 10 to the notched grooves 14d and 14e is preferably high enough to accommodate the coil portion 20.

  In FIG. 3A, the height H1 is the height from the inner bottom surface 18a to the upper end 12a of the center core 12, preferably smaller than the height H0 of the side wall 14, and the height H1 is subtracted from the height H0. The thickness of the lid core 30 is preferably approximately equal to the thickness of the lid core 30 in the Z-axis direction, and the outer surface 34 of the lid core 30 and the upper end 14 a of the side wall portion 14 are preferably substantially flush.

  A first adhesive 50 is interposed between the inner surface 32 of the lid core 30 and the upper ends of the center core portion 12 and the coil portion 20 to secure the bonding therebetween. The first adhesive 50 constitutes a first gap G <b> 1 between the lid core 30 and the center core 12. The first adhesive 50 is also filled in the recess 13 a to strengthen the bonding between the lid core 30 and the center core 12. The first gap G1 is not particularly limited, but is preferably 1 mm or less, and more preferably 0.05 to 0.3 mm. By setting in such a range, the balance between the reduction in height and the characteristics is excellent.

  The outer peripheral surface 36 of the lid core 30 preferably has a circumferential surface shape in accordance with the shape of the inner peripheral surface of the side wall portion 14, and as shown in FIG. However, as shown in FIGS. 3A and 3C, a predetermined air gap G2 may be provided.

  Further, in FIG. 3A, the height H2 is the height from the inner bottom surface 18a to the upper end of the coil portion 20, and considering that the thickness of the second adhesive 52 is small, the coil portion 20 itself in the Z axis direction It is almost the same as the height. In this embodiment, since the lead portions 22a and 22b are formed near the upper end of the coil portion 20, the height H3 is approximately the same as or slightly smaller than the height H2, but the lead portions 22a and 22b are coil portions When forming in the middle of the Z-axis direction of 20, the height H3 can be smaller than the height H2.

  The second adhesive 52 is provided not only between the inner bottom surface 18 a of the pot core 10 and the lower surface of the core 12 and the coil 20 but also between the outer peripheral surface of the coil 20 and the inner peripheral surface of the side wall 14. Be filled.

  The first adhesive 50 and the second adhesive 52 may be composed of the same material or may be composed of different materials, but have the same basic composition and are generally free of magnetic powder. Adhesives, for example, epoxy adhesives, silicone adhesives, polyimide adhesives, cyanoacrylate adhesives, modified acrylic adhesives, and the like.

  Alternatively, the first adhesive 50 and the second adhesive 52 may be, for example, a magnetic substance-containing resin containing magnetic powder in a resin such as epoxy and silicon. The magnetic powder may be the same as or different from the magnetic material constituting the pot core 10 or the lid core 30. For example, a metal magnetic material containing Fe, Si, Cr, B, C or the like can be used.

  The content of the magnetic powder contained in the magnetic substance-containing resin is preferably the same for the first adhesive 50 and the second adhesive 52, but may be different within a predetermined range. For example, the content of the magnetic powder contained in each of the first adhesive 50 and the second adhesive 52 is preferably 80 to 90% by weight with respect to the whole of each.

  Moreover, although it is preferable that the pot core 10 and the lid core 30 are comprised with the same magnetic body, you may comprise with a different magnetic body. Each of the pot core 10 and the lid core 30 is preferably, for example, an FeSiCr-based metallic magnetic body, and is preferably a magnetic body obtained by heat-treating a powder compact of metal powder at a high temperature (for example, 700 ° C.).

  It is preferable that the core part 12 and the pot core 10 and the lid core 30 be different magnetic bodies in this embodiment. For example, it is preferable that it is a compacting body of an iron-based metal powder and a resin (for example, epoxy 3%), for example, a magnetic body obtained by curing the resin at 150 ° C.

  In such a combination of magnetic materials, the magnetic permeability μ of the pot core 10 is higher than the magnetic permeability μ of the central core 12 and the saturation magnetic flux density Bs of the central core 12 is higher than the saturation magnetic flux density Bs of the pot core 10 Is an example of a combination of magnetic materials.

  Before the core part 12 and the coil part 20 shown in FIG. 2A are inserted into the recess 18, the second adhesive 52 before curing shown in FIG. After that, the coil portion 20 may be inserted into the recess 18 together with the core portion 12. The adhesive 52 before curing moves so as to extend in the gap between the outer peripheral surface of the coil portion 20 and the inner wall surface of the side wall portion 14 so as to stop immediately before overflowing from the notched grooves 14d and 14e. It is preferable to adjust the resin to be filled in advance.

  The first adhesive 50 before curing may be applied in advance to the inner surface 32 of the lid core 30 or the upper end 12 a of the center core 12, and thereafter, these may be bonded. The curing process of the first adhesive 50 and the second adhesive 52 can be performed by applying heat if the resin constituting the adhesive is a thermosetting resin, and the assembly is performed as shown in FIG. 3A. It is preferable to carry out later simultaneously. However, curing may be performed separately.

  As shown in FIG. 3A, after the curing treatment of the first adhesive 50 and the second adhesive 52 is completed, the terminals 40a and 40b shown in FIG. 2 may be attached or may be attached in front of them. In addition, bonding of the tips of the lead portions 22a and 22b and the installation pieces 46a and 46b is performed after the attachment of the terminals 40a and 40b.

  In the coil device 2 according to the present embodiment, the resin contained in the first adhesive 50 functions as the first gap G1 to improve the magnetic saturation and to improve the DC bias characteristics. When the first adhesive 50 contains a magnetic substance, the magnetic substance in the adhesive functions as a part of the core 12 (or the lid core 30) to improve the inductance.

  Furthermore, in the present embodiment, by forming the air gap G2 between the inner peripheral surface of the side wall portion 14 and the outer peripheral surface 36 of the lid core 30, the magnetic saturation is further improved and the DC bias characteristics are improved.

  Furthermore, in the present embodiment, as shown in FIG. 3A, the second adhesive 52 is interposed between the lower surface 12 b and the inner bottom surface 18 a of the center core 12, and a gap is also formed there. is there. Therefore, the DC bias characteristics can be further improved. When the second adhesive 52 contains magnetic powder, the inductance is further improved.

  Furthermore, in the present embodiment, the lead portions 22a and 22b of the wire 22 constituting the coil portion 20 are drawn out of the side wall portion 14 near the upper end of the coil portion 20, and the upper end 14a of the side wall portion 14 Grooves 14d and 14e are formed for drawing 22a and 22b outward.

  With this configuration, the second adhesive 52 can be filled in the gap between the inner wall surface of the recess 18 and the outer surface of the coil portion 20 to the maximum height. Further, by filling the second adhesive 52 in the recess 18 in advance to such an extent that the second adhesive 52 is not discharged to the outside through the grooves 14 d and 14 e, the core portion 12 is accommodated together with the coil portion 20 inside the recess 18. The second adhesive 52 can be filled in the gap between the inner wall surface of the recess 18 and the coil portion 20 to the maximum height.

  Furthermore, in the present embodiment, the first adhesive 50 is disposed at a position higher in the Z-axis direction than the second adhesive 52, so that the distance between the upper end of the coil portion 20 and the inner surface 32 of the lid core 30 is It becomes easy to form a gap.

  Particularly, in the coil device 2 according to the present embodiment, as shown in FIGS. 2A and 2B, the coil unit 20 is configured by edgewise winding the wire 22 having a flat cross section in two or more layers and in even layers. There is. Therefore, the pair of lead portions 22a and 22b which are both ends of the wire 22 are both located at the upper end of the coil portion 20, and the side wall portion of the pot core 10 is required without requiring an extra space inside the pot core 10. It can be easily pulled out from the top of 14. Therefore, the inductance of the coil device 2 can be increased, and the size and height of the coil device 2 can be reduced.

  Furthermore, since there is no need for an extra space for lead portion extraction inside pot core 10, the distance between the outer periphery of coil portion 20 and sidewall portion 14 of pot core 10 can be kept constant. The gap between the lid core 30 and the side wall portion 14 of the pot core 10 can be easily adjusted to the constant gap G2. For this reason, the control of the gap between the parts constituting the core is easy, the magnetic saturation is improved, and the DC bias characteristics are improved.

  Further, in the present embodiment, the coil portion 20 is not attached to the inside of the pot core 10 as an air core coil, but is disposed inside the pot core 10 in a state of being wound around the center portion 12. The distance between the portion 12 and the coil portion 20 is shortened, and the DC bias characteristics can be improved.

  Furthermore, in the present embodiment, it is easy to make the magnetic characteristics of the core portion 12 different from the magnetic characteristics of the pot core 10 and the lid core 30. For example, the magnetic permeability μ of the pot core 10 and the lid core 30 is higher than the magnetic permeability μ of the central core 12, and the saturation magnetic flux density Bs of the central core 12 is higher than the saturation magnetic flux density Bs of the pot core 10 and the lid core 30 By selecting a combination of magnetic materials, it is possible to improve the DC bias characteristics.

  Further, in the present embodiment, the pair of lead portions 22a and 22b of the wire 22 are drawn to the outside of the side wall portion 14 at a predetermined angle of 20 to 60 degrees, preferably 40 to 50 degrees. With such a configuration, the wire 22 having a flat cross section can be easily edge-wound in two layers around the core portion 12, and insulation between the pair of terminals 40a and 40b can be easily ensured.

  Having such terminals 40a and 40b facilitates downsizing of the coil device 2, and facilitates electrical connection and mechanical connection between the lead portions 22a and 22b and the terminals 40a and 40b. These connections are made, for example, by solder welding or laser welding or arc welding.

Second Embodiment As shown in FIG. 2D, the coil device according to the second embodiment differs from the first embodiment only in the structure of the terminal 40c, and the other parts are the same as the embodiment described above. It is common and produces the same effect. In the following, only the differences will be described.

  As shown in FIG. 2D, the terminal 40c of this embodiment has a flat terminal body 41c in close contact with the opposing outer peripheral surface 14c of the side wall portion 14 shown in FIG. 2A along the Z-axis direction. A lower locking piece 42c is integrally formed at the lower end of the terminal main body 41c in the Z-axis direction. The lower locking piece 42c shown in FIG. 2D is a member corresponding to the lower locking pieces 42a and 42b shown in FIG. 2A, but the width in the Y-axis direction is the same as that of the lower locking pieces 42a and 42b shown in FIG. It is shorter than that.

  In addition, a single locking projection 16b is formed on the inner surface of the lower locking piece 42c shown in FIG. 2D, and this locking projection 16b is an inside of the locking recesses 15a to 15c shown in FIG. 2C. Is fitted in a locking recess 15b located at the center in the Y-axis direction. The upper locking piece 43c, the connection piece 44c and the installation piece 46c shown in FIG. 2D have the same configuration as the connection pieces 44a and 44b and the installation pieces 46a and 46b of the first embodiment, and thus the description thereof will be omitted.

  The terminal 40c of the present embodiment can be used in place of the terminals 40a and 40b of the first embodiment, and the core 10, the lid core 30, the core 12 and the coil 20 can be shared.

Third Embodiment The coil device according to the present embodiment shown in FIG. 3B is different from the lid core 30 of the first embodiment only in the structure of the lid core 30a, and the other parts are the same as those of the embodiment described above It produces the same effect. In the following, only the differences will be described.

  As shown in FIG. 3B, a plurality of gap adjusting convex portions 33 are formed on the inner surface 32 of the lid core 30a of this embodiment, and the convex portions 33 abut on the upper end 12a of the center core portion 12, The first gap G1 shown in 3A can be adjusted to a predetermined value. From such a viewpoint, it is preferable that the protrusion height H1 from the inner surface 32 of the convex portion 33 be substantially equal to the first gap G1 shown in FIG. 3A.

  The inner surface 32 of the lid core 30a and the upper end 12a of the center core 12 may be bonded with an adhesive containing no magnetic powder. The same applies to the other embodiments.

Fourth Embodiment As shown in FIG. 3C and FIG. 4, in the coil device 2a according to the present embodiment, the bottom of the core 12A is formed integrally with the bottom plate 11 of the pot core 10a. The only difference is that a coil unit 20a made up of an air core coil is disposed around the unit 12A, and the other parts are the same as those of the above-described embodiment, and the same effects can be obtained. In the following, only the differences will be described.

  As shown in FIG. 3C, the bottom of the center core 12A is integrally formed with the bottom plate 11 of the pot core 10a. Therefore, as shown in FIG. 4, it is difficult to wind the wire 22 with a flat cross section directly around the core portion 12A, and an air core coil formed in a coil shape in advance as the coil portion 20a. Use

  Also in the coil portion 20a formed of the air core coil, the wire 22 having a flat cross section is edgewise wound on two or more layers of even numbered turns. In order to insert the coil portion 20a formed of an air core coil, which is formed in advance, into the ring-shaped gap between the core portion 12A and the side wall portion 14, the outer diameter D1 of the core portion 12A is larger than that of the coil portion 20a. It is preferable that the inner diameter D2 be somewhat large and the outer diameter d2 of the coil portion 20a be slightly smaller than the inner diameter d1 of the inner peripheral surface of the side wall portion 14.

  The present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention.

2, 2 ... Coil device 10 ... Pot core 11 ... Bottom plate 12, 12A ... Core part 12a ... Upper end 14 ... Side wall part 14a ... Upper end 14d, 14e ... Extraction groove 18 ... Concave portion 18a ... Inner bottom surface 20, 20a ... Coil portion 22 ... Wires 22a, 22b ... Leads 30, 30a ... Lid core 32 ... Inner surface 34 ... Outer surface 36 ... Outer peripheral surface 40a, 40b, 40c ... Terminals 41a, 41b, 41c ... Terminal bodies 42a, 42b, 42c ... Lower locking piece 43a , 43b, 43c ... Upper locking pieces 44a, 44b, 44c ... Coupling pieces 46a, 46b, 46c ... Installation piece 50 ... First adhesive 52 ... Second adhesive

Claims (8)

And the center part,
A pot core having side wall portions surrounding the periphery of the center core portion at a predetermined interval;
A coil portion disposed between said side wall portion and the center-core portion,
A coil device comprising: a lid core covering an upper portion of the coil portion and an upper portion of the center portion;
The coil portion is configured by edgewise winding a wire having a flat cross section in two or more layers,
A pair of lead portions which are both end portions of the wire are drawn out from the upper end of the side wall portion ,
A pair of the lead portions of the wire are respectively drawn out of the side wall portion at a predetermined angle of 20 degrees to 60 degrees, and are connected to a pair of terminals attached to the outer surface of the side wall portion Coil device.   The coil device according to claim 1, wherein a bottom portion of the core portion is fixed to a bottom plate portion of the pot core in a state where the coil portion is attached to an outer periphery of the core portion.   The coil device according to claim 2, wherein the bottom of the core portion is fixed to the bottom plate of the pot core by an adhesive.   The coil device according to claim 2, wherein a bottom portion of the core portion is fixed to a bottom plate portion of the pot core by a magnetic substance-containing resin.   The coil device according to any one of claims 2 to 4, wherein the magnetic properties of the core portion and the magnetic properties of the pot core are different.   The coil device according to claim 1, wherein a bottom portion of the core portion is formed integrally with a bottom plate portion of the pot core.   A pair of the lead portions of the wire is drawn to the outside of the side wall portion near the upper end of the coil portion, and a lead groove for drawing the lead portion to the outside is formed on the upper end of the side wall portion The coil device according to any one of claims 1 to 6. The terminal is
A terminal body attached to an outer peripheral surface of the side wall portion;
A lower locking piece formed at the lower end portion of the terminal body and locked to the lower end surface of the side wall portion;
An upper locking piece formed at an upper end portion of the terminal body and locked to an upper end surface of the side wall portion;
An installation piece disposed outside the lead groove;
The coil device according to claim 7 , further comprising: a connection piece integrally connecting the installation piece and the terminal body.

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