CN111834096A - Coil device - Google Patents

Abstract

The invention provides a coil device, which is easy to adjust leakage characteristics and can realize thinning. The coil device has: a spool (40) having a first winding section (45) that winds a first winding (22) around the outer periphery thereof; and a spool cover (50) that covers the periphery of the spool (40) around which the first winding (22) is wound. The spool cover (50) has a second winding portion (55) for winding a second winding (32) different from the first winding (22) around the outer periphery thereof, and a non-winding portion disposed at a lower position or an upper position along the axial direction of the second winding portion (55), wherein the number of sub-winding layers of the first winding (22) wound around a first sub-winding portion (45b) of a first winding portion (45) located inside the non-winding portion is larger than the number of main winding layers of the first winding (22) wound around a first main winding portion (45a) of the first winding portion (45) located inside the second winding portion (55).

Description

Coil device

Technical Field

The present invention relates to a coil device that can be suitably used as, for example, a transformer.

Background

As a coil device used for a transformer or the like, for example, a coil device shown in patent document 1 is known. In such a conventional coil device, the coil located on the inner side is wound around the outer peripheral surface of the bobbin arranged on the inner side, the periphery thereof is surrounded by the bobbin cover, and the coil located on the outer side is wound around the outer periphery thereof.

In such a coil device, adjustment of coupling between the outer coil and the inner coil (for example, adjustment of leakage characteristics) is generally performed by shifting the positions of the inner coil and the outer coil in the axial direction, or the like.

However, it is difficult to achieve a low height of the coil device by adjusting the inter-coil coupling only by shifting the axial positions of the inner coil and the outer coil as in the conventional art.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 6268509

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made in view of such circumstances, and an object thereof is to provide a coil device that can easily adjust coupling between coils and can be made thin.

Means for solving the problems

In order to achieve the above object, the present invention provides a coil device including:

a bobbin having a first winding portion for winding a first winding wire around an outer periphery thereof;

a spool cover that covers a periphery of a spool around which the first winding wire is wound,

the spool cover includes a second winding portion for winding a second winding different from the first winding around an outer periphery thereof, and a non-winding portion disposed at a lower position or an upper position along an axial direction of the second winding portion,

the number of sub-winding layers of the first winding wound around the first sub-winding portion of the first winding portion located inside the non-winding portion is larger than the number of main winding layers of the first winding wound around the first main winding portion of the first winding portion located inside the second winding portion.

In the coil device of the present invention, the adjustment of the inter-coil coupling (e.g., the adjustment of the leakage characteristic) can be achieved by the gap in the radial direction between the first wire wound around the first main winding portion and the second wire wound around the second winding portion. In the coil device of the present invention, the inter-coil coupling can be adjusted by the axial gap between the first winding wire wound around the first sub-winding portion and the second winding wire wound around the second winding portion. Further, if the number of winding layers of the first wire wound around the first sub-winding portion is increased, the overlapping area of the first wire and the second wire viewed from the axial direction is also increased, and the inter-coil coupling can be adjusted. In this way, in the coil device of the present invention, the adjustment of the coupling between the coils is easily performed by both the radial gap and the axial gap.

In the coil device of the present invention, the number of winding layers of the first winding wound around the first sub-winding portion of the first winding portion is increased, so that the total number of turns of the first winding can be increased, and the axial dimension of the bobbin can be shortened. Therefore, the height of the coil device can be reduced.

Preferably, the outermost layer of the first winding wound around the first sub-winding portion is located outside a cylindrical wall of the second winding portion. With this configuration, the first and second wound wires overlap each other when viewed in the axial direction. Therefore, the adjustment of the inter-coil coupling is easily achieved by the axial gap between the first winding wire wound around the first sub-winding portion and the second winding wire wound around the second winding portion.

Preferably, the first winding wire wound around the first sub-winding portion and the second winding wire wound around the second winding portion overlap each other when viewed in the axial direction. With this configuration, the inter-coil coupling can be easily adjusted by the axial gap between the first winding wire wound around the first sub-winding portion and the second winding wire wound around the second winding portion.

Preferably, the first winding portion has a winding partition wall flange formed at a predetermined interval in the axial direction. With this configuration, the first winding can be easily wound with α. Preferably, a winding partition wall flange that separates the first main winding portion from the first sub-winding portion has a projection projecting outward beyond an outer edge end of the winding partition wall flange formed in a range of the first main winding portion. The projection can function as a positioning for the spool lid.

Preferably, the projection is formed with a notch that forms a flow gap penetrating in the axial direction. Through the slit, highly thermally conductive resin such as potting resin can flow in the axial direction. As a result, the high thermal conductive resin spreads over the inner coil portion formed of the first winding located inside, and the heat dissipation performance is improved.

Preferably, the spool cover has:

a second hollow tube portion that constitutes the second wound portion;

a pair of cover flange portions formed at both ends of the second hollow tube portion in the axial direction,

a plurality of gap retaining pieces constituting the non-winding portion are intermittently formed along a circumferential direction on an outer periphery of at least any one of the cover flange portions,

the first sub-wound portion is located inside the gap retaining sheet.

With this configuration, the first winding wire can be easily wound around the outer periphery of the first sub-winding portion.

Preferably, the gap retaining piece has an opening portion formed therein to connect an outer side and an inner side of the gap retaining piece. With this configuration, the highly thermally conductive resin such as potting resin can flow radially inward through the opening. As a result, the high thermal conductive resin spreads over the inner coil portion formed of the first winding located inside, and the heat dissipation performance is improved. The position of the opening is preferably formed to correspond to the position of the notch for forming the projection. This is because the highly thermally conductive resin easily flows inside the bobbin case.

Preferably, the first winding is wound around the first main winding portion and the first sub-winding portion α. By setting the α winding, the first winding can be easily wound, and the axial length of the coil portion formed by the first winding can be shortened. In addition, the first winding wire having a plurality of turns can be easily wound around the outer periphery of the first sub-winding portion.

Preferably, the coil device further includes a case that houses the high thermal conductive resin such that the first winding portion of the bobbin and the second winding portion of the bobbin case are filled with the high thermal conductive resin. With this configuration, the height of the coil device can be reduced, and the heat dissipation performance can be further improved.

Drawings

Fig. 1A is a perspective view of a coil device according to a first embodiment of the present invention.

Fig. 1B is a perspective view of a coil device according to a second embodiment of the present invention.

Fig. 2A is an exploded perspective view of the coil device shown in fig. 1.

Fig. 2B is an exploded perspective view when the components attached to the bobbin are detached from the coil device shown in fig. 2A.

Fig. 2C is an exploded perspective view when the components attached to the bobbin are detached from the coil device shown in fig. 2B.

Fig. 2D is a perspective view showing the lead portion of the outer coil shown in fig. 2B and its peripheral structure.

Fig. 2E is an exploded perspective view of the coil device shown in fig. 2B with the lead wire drawing block attached to the bobbin removed.

Fig. 3 is a cross-sectional view of the coil arrangement taken along line III-III shown in fig. 1A.

Fig. 4A is a perspective view showing a lead portion of an outer coil and a peripheral structure thereof in the coil device shown in fig. 1A.

Fig. 4B is a perspective view showing a lead portion of an outer coil and a peripheral structure thereof in the coil device shown in fig. 1B.

Fig. 5A is an exploded perspective view of the insulation protection part shown in fig. 4A.

Fig. 5B is an exploded perspective view of the insulation protection part shown in fig. 4B.

Fig. 6 is a schematic perspective view illustrating winding of the first winding α around the bobbin.

Detailed Description

The present invention will be described below based on embodiments shown in the drawings.

First embodiment

As shown in fig. 1A, a coil device 10 according to an embodiment of the present invention includes a case 300, and a main portion of the coil device 10 is housed inside the case 300. In the present embodiment, the X axis, the Y axis, and the Z axis are perpendicular to each other, the direction perpendicular to the mounting surface of the coil device 10 is the Z axis, and the direction in which the pair of terminals 91 and 92 and the pair of terminals 91 and 92 are located on the opposite side to each other is the X axis.

As shown in fig. 2A, in the case 300, the bottom plate 340 is joined to a frame body 305 having an outer surface 310 and an inner surface 320, and an opening edge portion 315 on the Z-axis lower side of the frame body 305. The upper plate or the like is released in the upward direction without being engaged with the opening edge portion 330 on the Z-axis upper side of the housing 305, and the main portion of the coil device 10 can be inserted from above. In the four corners of the housing 305, concave corners 350 may be formed so as to be recessed inward of the housing 305 in accordance with the overall shape of the coil device 10.

The housing 305 of the case 300 is preferably made of metal or the like having good thermal conductivity. The metal constituting the housing 305 is not particularly limited, but aluminum, an aluminum alloy, copper, a copper alloy, stainless steel, and the like are exemplified. The housing 305 of the housing 300 can be manufactured by, for example, extrusion, press working, die casting, or the like.

Similarly, the bottom plate 340 is preferably made of the same metal as the housing 305, but may be made of a metal that is not exactly the same as the housing 305. The bottom plate 340 is joined to the housing 305 by an adhesive or the like, but may be joined to the housing 305 by bolts, nuts, or the like. Further, the bottom plate 340 and the frame body 305 may be integrally formed. The cooling device such as a cooling pipe or a cooling blade may be attached to the lower side of the casing 300 through a metal plate or the like, or the cooling device such as a cooling pipe or a cooling blade may be directly attached to the lower side of the casing 300.

A highly thermally conductive resin is housed in the case 300 in advance, and the main portion of the coil device 10 is impregnated with the highly thermally conductive resin in the case 300. The high thermal conductive resin is not particularly limited, but is preferably a resin having a thermal conductivity of 0.5 to 5W/mK, preferably 1 to 3W/mK, and excellent heat dissipation properties.

Examples of the resin having excellent high thermal conductivity include a silicone resin, a polyurethane resin, and an epoxy resin, and among them, a silicone resin and a polyurethane resin are preferable. In addition, in order to improve heat dissipation, a filler having high thermal conductivity may be filled in the resin. The high thermal conductive resin according to the present embodiment preferably has a shore a hardness of 100 or less, and preferably 60 or less. As such a resin, a potting resin is exemplified.

As shown in fig. 2A, the coil device 10 has four cores 12, a bobbin 40, a bobbin cover 50, and two core covers 60. The four cores 12 are assembled to form a magnetic path through which magnetic flux generated by a coil described later passes. These cores 12 have a symmetrical shape, and are connected to each other by sandwiching the spool cover 50 and the spool 40 from the vertical direction (the Z-axis direction in the drawing).

Each core 12 is a core having a substantially E-shaped longitudinal section (including cut surfaces of the Y-axis and the Z-axis). Each core 12 is made of a soft magnetic material such as ferrite or a metallic magnetic material, and includes a flat plate-like base 13 extending in the Y-axis direction, a pair of side legs 16, 16 protruding in the Z-axis direction from both ends of each base 13 in the Y-axis direction, and a middle leg 14 protruding in the Z-axis direction from a middle position of each base 13 in the Y-axis direction.

In the present embodiment, the stem 14 of each core 12 enters the first through hole 44a formed in the first hollow cylindrical portion 44 of the bobbin 40. The cores 12 and 12 adjacent to each other in the X-axis direction have a gap therebetween by the separation convex portion 44b formed on the inner peripheral wall of the first hollow cylindrical portion 44. The heat dissipation property of the heat generated inside the coil device 10 is improved by the high thermal conductive resin such as potting resin entering the gap.

The gap formed by the separation projection 44b corresponds to the thickness of the separation projection 44b in the X-axis direction. The separating projections 44b are formed along the Z axis in the center portion in the X axis direction and on both sides in the Y axis direction inside the through hole 44 a. The thickness of the separating projection 44b in the X-axis direction is not particularly limited, but is preferably 0.05 to 5mm, and more preferably 0.1 to 3 mm.

As shown in fig. 2B, the bobbin 40 has a bobbin base plate 42 of a substantially elliptical flat plate shape at a lower end portion in the Z-axis direction thereof. As shown in fig. 3, the first hollow cylindrical portion 44 is integrally formed in a substantially central portion of the bobbin base plate 42 so as to extend upward in the Z-axis direction.

As shown in fig. 3, the above-bobbin flange portion 48 is integrally formed on the upper portion of the first hollow cylindrical portion 44 in the Z-axis direction so as to project radially from the first hollow cylindrical portion 44 on the Y-X axis plane. As shown in fig. 2C, lead drawing tables 491 are integrally formed on both ends of the on-axis flange portion 48 in the X-axis direction, respectively. The lead drawing portions 49 formed separately from the bobbins 40 may be joined to the lead drawing tables 491 by fitting, bonding, or the like. The lead drawing portion 49 may be formed integrally with the bobbin 40.

In the present embodiment, each lead drawing portion 49 is constituted by a lead drawing block 490 as a terminal block, and as shown in fig. 2C, the pair of lead portions 22a, which are both end portions of the first winding 22 constituting the inner coil 20, of the single lead drawing block 490 has a base 49C, and a pair of vertical drawing grooves 490e, which are drawn upward in the Z-axis direction, are formed in the base 49C. The base 490a is formed with a horizontal drawing groove 490f, and the horizontal drawing groove 490f guides the upper part of the vertical drawing groove 490e in the Z-axis direction to the opposite side in the Y-axis direction. The lead portions 22a, 22a are guided to the horizontal lead grooves 490 f. Lead connection pieces 91a, 92a of the terminals 91, 92 are connected to the distal ends of the lead portions 22a, 22 a. The terminals 91 and 92 are fitted into the base 490a and integrated with each other, but may be integrated without being fitted into the base 490 a.

The other lead drawing block 490 shown in fig. 2C has the same structure except that the lead portion 22a of the one lead block 490 is replaced with the lead portion 32 a. That is, the other lead drawing block 490 shown in fig. 2C includes a base 490a, and a pair of vertical drawing grooves 490e are formed in the base 490a, and the pair of vertical drawing grooves 490e draw out a pair of lead portions 32a, which are both end portions of the second winding 32 constituting the outer coil 30, in the Z-axis upward direction, respectively. The base 490a is formed with a horizontal drawing groove 490f, and the horizontal drawing groove 490f guides the upper part of the vertical drawing groove 490e in the Z-axis direction to the opposite side in the Y-axis direction. The lead portions 32a, 32a are guided to the horizontal lead grooves 490 f. Lead connecting pieces 91a, 92a of terminals 91, 92 are connected to the tips of the lead portions 32a, 32 a. The terminal is fitted into and integrated with the base 490a, but may not be fitted into the base 490 a.

As shown in fig. 3, a first winding portion 45 is formed on the outer peripheral portion of the first hollow cylindrical portion 44 located between the bobbin upper flange portion 48 and the bobbin base plate 42. In the first winding portion 45, as shown in fig. 6, a plurality of winding partition wall flanges 46, which separate winding portions adjacent to each other along the winding axis (Z axis) of the first winding wire 22 from each other, are formed integrally with the first hollow tube portion 44 substantially in parallel with the bobbin base plate 42 (and the bobbin upper flange portion 48) at predetermined intervals along the winding axis. The details of the winding partition wall flange 46 and the winding method of the first winding wire 22 will be described later.

The bobbin base plate 42, the first hollow cylindrical portion 44, the bobbin upper flange portion 48, and the winding partition flange 46 of the bobbin 40 are preferably integrally formed by injection molding or the like.

As shown in fig. 3, a first through hole 44a penetrating in the Z-axis direction is formed in the first hollow tube portion 44 of the bobbin base plate 42. The center leg 14 on the core 12 enters the first through hole 44a from above and below in the Z-axis direction, and the tip of the center leg 14 approaches the first through hole 44a at a substantially central portion of the through hole 44a in the Z-axis direction. In the substantially central portion of the through hole 44a in the Z-axis direction, the tip of the middle leg 14 inserted from above and below the Z-axis may be spaced apart from each other at a predetermined interval without contact.

As shown in fig. 2C, the bobbin case 50 is composed of a pair of halves 50a, 50b dividable into two in the X-axis direction, and is combined by a division connecting portion 53 parallel to the winding axis (Z-axis), and in the combined state, a second winding portion 55 is formed on the outer peripheral portion of the case 50. As shown in fig. 3, after the inner coil 20 is formed by winding the first winding wire 22 around the first winding portion 45 of the bobbin 40, the bobbin cover 50 is attached to the outer periphery of the bobbin 40 and combined by the division and connection portion 53 shown in fig. 2C.

As shown in fig. 2C, the bobbin case 50 has a second hollow tube portion 54 covering the inner coil 20 from the outside, and a case lower flange portion 52 and a case upper flange portion 58 are formed along the circumferential direction at a predetermined interval in the Z-axis direction on the outer peripheral portion of the second hollow tube portion 54. The lower flange portion 52 and the upper flange portion 58 are provided parallel to the plane of the X-Y axis and extend parallel to the installation surface.

Between these lower flange portion 52 and upper flange portion 58 is a second winding portion 55, and a second winding 32 constituting, for example, the outer coil 30 which is a secondary coil is wound in line (or α -wound) on this second winding portion 55. The parallel winding is a general winding method in which a winding wire is wound from one end of a winding shaft to the other end. The α winding will be described later.

As shown in fig. 2B, a pair of core covers 60 are attached to the outer periphery of the bobbin cover 50 to which the outer coil 30 is attached from both sides in the Y-axis direction. The core cover 60 is made of an insulating member such as a synthetic resin, and has a cover main body 62 whose outer peripheral surface is a guide surface for guiding the side legs 16 on the core 12 and whose inner peripheral surface is the outer coil 30.

Mounting rims 64, 64 are integrally formed at both ends of the cover main body 62 in the Z-axis direction. The mounting flange 64 on the upper Z-axis side engages with the upper surface of the bobbin upper flange 48, the mounting flange 64 on the lower Z-axis side engages with the lower surface of the bobbin base plate 42, and the core cover 60 is mounted on the bobbin 40.

The cover main body 62 has an inner peripheral surface shape corresponding to the outer peripheral surface shape of the core cover 60, and insulating plate portions 66 are integrally formed at both ends in the X-axis direction thereof. Engaging protrusions 66a protruding inward in the Y-axis direction are formed on the upper and lower sides of the insulating plate portion 66 in the Z-axis direction. The engaging convex portion 66a on the upper side of the Z axis engages with the inner surface of the insulating wall 491e of the bobbin 40, and the engaging convex portion 66a on the lower side of the Z axis engages with the lower surface of the bobbin base plate 42 at both ends of the X axis of the bobbin base plate 42.

As a result, as shown in fig. 2E, the insulation plate portion 66 of the core cover 60 is combined with the insulation wall 491E and the bobbin substrate 42, thereby improving the insulation between the core 12 shown in fig. 2A and the outer coil 30 shown in fig. 2E. The inner surface of the insulating plate portion 66 (the center side of the coil device 10) may be in contact with the core 12, or may have a shape conforming to the outer shape of the core 12.

As shown in fig. 3, in the present embodiment, the winding partition wall flange 46 in an elliptical ring shape is formed on a plane substantially parallel to the X-Y axis such that winding sections 47 at predetermined intervals are formed on the outer peripheral portion of the first hollow cylindrical portion 44 in a substantially elliptical cylindrical shape along the Z-axis direction. In the present embodiment, the plurality of winding partition wall flanges 46 are formed substantially in parallel at predetermined intervals along the Z-axis direction, but the number thereof is not particularly limited. These regions where the partition wall flanges 46 are formed are the first wound portions 45.

The winding section width along the winding axis (Z axis) of each winding section 47 separated by the winding partition flange 46 is set to a width that allows only one winding wire 22 to enter. That is, the winding division width w1 is preferably in the relationship of d1 < w1 < (2 × d1), more preferably d1 < w1 < (1.2 × d1), with respect to the wire diameter d1 of the winding 22. If the winding section width w1 is too wide relative to the wire diameter d1, winding disorder is likely to occur, and the requirement for compactness of the coil device is violated.

Note that, in each winding section 47, the winding section widths are preferably all the same, but may be slightly different. The winding section width between the bobbin upper flange portion 48 and the winding partition flange 46 at the uppermost position may be larger than the winding section width between the winding partition flanges 46. Similarly, the winding section width between the bobbin base plate 42 and the winding partition wall flange 46 positioned at the lowermost position may be larger than the winding section width between the winding partition wall flanges 46. In the present embodiment, the predetermined total winding number of the winding sections 47 is not particularly limited.

As shown in fig. 2C, in the present embodiment, the partition projecting piece 46d for inserting the lower surface of the cover lower flange portion 52 of the bobbin cover 50 into the winding partition flange 46 closest to the bobbin base plate 42 and positioning the same is intermittently formed in a part in the circumferential direction. As shown in fig. 6, a flow gap 46e through which the high thermal conductive resin can flow in the axial direction is formed in a slit shape between the outer peripheral surface of the winding partition wall flange 46 and the inner peripheral surface of the bobbin case 50 at a portion other than the partition projecting piece 46 d.

The partition projecting piece 46d preferably projects from the outer peripheral surface of the winding partition flange 46 also at the position of the divided connecting portion 53 of the spool cover 50. The projecting height (radial height) of the partition tabs 46d specifies the radial width of the flow-through gap 46 e.

The bobbin cover 50 is constructed by inserting the outer connecting piece 53b of the other half 50b radially outward of the inner connecting piece 53a of the one half 50a at the divided connecting portion 53 of the bobbin cover 50, and connecting the halves 50a, 50 b.

The bobbin case 50 includes a second winding portion 54 that winds the second winding wire 32 different from the first winding wire 22 around the outer periphery, and a gap retaining piece 52a that is a non-winding portion disposed below the second winding portion 54 in the axial direction. The gap retaining piece 52a as the non-winding portion has an opening 52b or a notch that communicates the inside and the outside of the spool cover 50. The gap retaining pieces 52a are formed to extend in the Z-axis downward direction from the outer peripheral edge of the cover lower flange portion, and the lower ends thereof can abut against the upper surface of the bobbin base plate 42.

The openings 52b are formed in the half bodies 50a and 50b positioned on both sides in the X-axis direction, respectively, and at positions corresponding to the flow gaps 46e of the partition fins 46d provided in the partition flange 46 of the bobbin 40. As shown in fig. 2E, the gap retaining pieces 52a are not formed on the outer peripheral edge of the cover lower flange portion 52 at the end in the X-axis direction, and a high thermal conductive resin or the like can freely enter from the gap between the cover lower flange portion 52 and the bobbin substrate 42.

As shown in fig. 2C, a stepped upper flange portion 58a that is higher than the other portions along the Z axis is formed in the cover upper flange portion 58 of the connecting portion 53a of the one half body 50 a. The cover upper flange portion 58 positioned at the connecting portion 53b of the other half body 50b is formed with an upper flange portion 58b positioned below the upper flange portion 58a along the Z axis and capable of being inserted and connected to the upper flange portion 58 a.

Further, a stopper protrusion 58i that can be brought into contact with the connection tip of the upper flange portion 58a is formed on the cover upper flange portion 58 positioned at the connection portion 53b of the other half body 50 b. The stopper projection 58i projects upward in the Z axis direction with respect to most of the upper surface of the cover upper flange portion 58. The height of projection of the stopper projection 58i with respect to the most upper surface of the cover upper flange portion 58 is preferably substantially the same as the height of projection along the Z-axis connecting the upper flange portion 58 a. The upper surfaces of these stopper projections 58i and the upper surface of the upper connecting flange portion 58a are in contact with the lower surface of the upper bobbin flange portion 48 of the bobbin 40, and an air outlet gap is formed between the upper surface of the upper cover flange portion 58 and the lower surface of the upper bobbin flange portion 48 in most portions except for the divided connecting portion 53.

The cover upper flange portion 58 on the opposite side of the upper flange portion 58a along the X axis of the one half body 50a includes an engaging convex portion 58c protruding above the upper surface of the cover upper flange portion 58 along the Z axis. An engaging surface 58e is formed on the upper surface of the engaging convex portion 58c, and the protruding height of the engaging surface 58e along the Z axis with respect to the upper surface of the lid upper flange portion 58 is approximately the same as the step height of the connecting flange portion 58 a. The engaging surface 58e contacts the lower surface of the lead drawing table 491. The lower surface of the lead-out table 491 is substantially the same height as the lower surface of the flange portion 48 on the bobbin along the Z axis. A stepped convex portion 58g may be formed on the upper surface of the cover upper flange portion 58 positioned between the engaging portion 58c and the upper flange portion 58 a. The step height of the step convex portion 58g is the same as the step height of the connecting flange portion 58 a.

The cover upper flange portion 58 on the opposite side of the upper flange portion 58b from the connection portion 50b along the X axis of the other half body 50b includes an engagement convex portion 58d protruding above the upper surface of the cover upper flange portion 58 along the Z axis. An engaging surface 58f is formed on the upper surface of the engaging convex portion 58d, and the protruding height of the engaging surface 58f along the Z axis with respect to the upper surface of the lid upper flange portion 58 is approximately the same as the protruding height of the stopper convex portion 58 i. The engaging surface 58f contacts the lower surface of the lead drawing table 491. The lower surface of the lead drawing table 491 is substantially the same height as the lower surface of the flange portion 48 on the bobbin along the Z axis. A stepped convex portion 58h may be formed on the upper surface of the cover upper flange portion 58 between the engaging portion 58d and the stopper convex portion 58 i. The step height of the step protrusion 58h is the same as the step height of the stopper protrusion 58 i.

The first winding 22 shown in fig. 2C may be formed of a single wire or a stranded wire, and is preferably formed of an insulated coated wire. The outer diameter d1 of the first winding 22 is not particularly limited, but is preferably set when a large current flows, for example

The second winding 32 may be the same as or different from the first winding 22.

In this embodiment, the inner coil 20 formed of the first winding 22 forms a primary coil of the transformer, and the outer coil 30 formed of the second winding 32 wound around the bobbin case 50 forms a secondary coil. Therefore, in the present embodiment, as shown in fig. 3, the second winding 32 constituting the outer coil 30 has a larger wire diameter than the first winding 22, but the wire diameter is not particularly limited, and may be the same or different. The first winding 22 and the second winding 32 may be made of the same material or different materials.

As shown in fig. 6, in the spool 40 of the present embodiment, at least one coupling groove 46a for coupling adjacent winding sections 47 to each other is formed in each winding partition wall flange 46. In the present embodiment, the circumferential position of at least one of the pair of cut edges 46b, 46c formed in the winding partition wall flange 46 so as to define the circumferential width of each coupling groove 46a differs between the winding partition wall flanges 46 adjacent in the Z-axis direction (winding axis), but the circumferential position may be the same. The circumferential direction is a direction along the elliptical outer peripheral surface of the hollow cylindrical portion 44.

In the present embodiment, as shown in fig. 6, one notched edge portion 46c of the pair of notched edge portions 46b and 46c is uniformly inclined in the right-downward direction, and the other notched edge portion 46b is uniformly inclined in the right-downward direction at a portion other than the partition wall flange portion 46 where the partitioning fin 46d is formed. Only in the partition wall flange portion 46 where the partition projecting piece 46d is formed, the notch edge portion 46b is inclined in the opposite direction so that the circumferential width of the coupling groove 46a is wider than the other portions.

In the bobbin 40 of the present embodiment, the first winding 22 is wound from, for example, the center portion in the Z-axis direction of the first winding portion 45 by α winding. That is, the center portion 22b of the first winding 22 is disposed so that the lower winding portion 22c passes through the next-stage winding section 47 from the center toward one end of the first winding 22 through the connection groove 46a located at the center in the Z-axis direction of the first winding 45. The other upper wound portion 22d is passed through the winding section 47 located at the previous stage of the winding section 47 through which the lower wound portion 22c is passed, from the center portion of the first winding 22 toward one end.

Thereafter, the lower wound portion 22c is wound one or more times to the right in the same winding section 47 as viewed from the Z axis, and the upper wound portion 22d is wound one or more times to the left in the same winding section 47 at the upper stage as viewed from the Z axis. Thereafter, the lower wound portion 22c is moved from the wound winding section 47 to the winding section 47 of the next stage in the Z-axis direction through the connection groove 46a, and is wound in the same direction in this winding section 47. The upper wound portion 22d is moved from the wound section 47 to the winding section 47 one step above in the Z-axis direction through the connection groove 46a, and is wound in the same direction in the winding section 47.

By repeating this operation, the first winding α is wound around the first winding portion 45. In the present embodiment, the first winding portion 45 is divided into a first main winding portion 45a located between the partition tab 46d and the bobbin upper flange portion 48, and a first sub-winding portion 45b located between the partition tab 46d and the bobbin base plate 42. As shown in fig. 3, the first winding 22 is wound in the first main winding portion 45a in one or more layers in the radial direction α, and the first winding 22 α is wound in the first sub-winding portion 45b in a number of layers (first sub-winding layers) greater than the number of radial winding layers (first main winding layers) wound in the first main winding portion 45 a.

The outermost layer of the first winding 22 wound around the first sub-winding portion 45b is located outside the cylindrical wall of the second winding portion 55. With this configuration, the flange-like coil portion 20a of the first wire 22 wound around the first sub-winding portion 45b and the outer coil portion 30 of the second wire 32 wound around the second winding portion 55 overlap each other when viewed from the axial direction.

The lead portion 22a from the flange-shaped coil portion 20a located at the lowermost end of the lower wound portion of the first winding wire 22 after the α -winding shown in fig. 3 is drawn out from the gap between the bobbin substrate 42 and the cover lower flange portion 52 shown in fig. 2D to the outside of the bobbin cover 50 in the X-axis direction. The lead portion 22a drawn out to the outside of the bobbin case 50 is raised upward in the Z-axis direction along the lead passage 240 of the insulating plate 200.

The lead passage 240 is formed between a pair of outward-plate protruding pieces 230, and the pair of outward-plate protruding pieces 230 are formed in the plate main body 210. A plate top plate 220 is formed on the plate body 210 in the Z-axis direction. The top plate 220 is inserted between the lead-wire drawing table 491 of the bobbin 20 and the engaging portion 58d of the bobbin case 50 and fixed.

The lead wire 22a rising upward in the Z-axis direction along the lead passage 240 of the insulating plate 200 is led out above the lead wire lead-out portion 49 through a base lead-out groove 491a formed in the lead wire lead-out table 491. The lead portion 22a drawn out above the lead drawing table 491 passes through the vertical drawing groove 490e of the lead drawing block 490 shown in fig. 2C. The lead drawing portion 22a inserted into the vertical drawing groove 490e is drawn outward in the Y-axis direction along the horizontal drawing groove 490f of the block 490, and is connected to the lead connecting piece 92a of the terminal 92.

As shown in fig. 2D, the lead portion 22a from the upper wound portion of the first wire 22 wound by α shown in fig. 2C passes through the other base lead-out groove 491C of the lead wire connecting base 491. The lead portion 22a passed through the base lead-out groove 491C passes through the vertical lead-out groove 490e of the base block 490 shown in fig. 2C. The lead drawing portion 22a inserted into the vertical drawing groove 490e is drawn outward in the Y-axis direction along the horizontal drawing groove 490f of the block 490, and is connected to the lead connecting piece 91a of the terminal 91. In the present embodiment, "outer" refers to a side of the bobbin 40 away from the central axis, and "inner" refers to a side of the bobbin close to the central axis.

On the other hand, as shown in fig. 3, in the bobbin case 50, the second winding 32 constituting the outer coil 30 serving as the secondary coil is wound in a row in the second winding portion 55. The aligned winding is a winding method in which the winding wire 32 is sequentially wound around the outer circumferential surface of the winding portion 55 from one end to the other end in the Z-axis direction, and in the present embodiment, one or two or more layers are aligned and wound in the radial direction. In both the case of the aligned winding of the two layers and the case of the aligned winding, the first layer is wound first, and then the second layer is wound thereon.

Each lead portion 32a of the second winding 30 constituting the outer coil 30 shown in fig. 2C is led out to the upper side of the lead-out table 491 through a passing groove formed in the engaging portion 58C of the bobbin case 50 and a base-drawn groove 491C of the lead-out table 491 shown in fig. 2E. The lead portions 32a and 32a led out above the lead drawing table 491 pass through the vertical drawing groove 490E of the base block 490 shown in fig. 2E. The lead drawing portions 22a, 22a inserted into the vertical drawing grooves 490e are drawn outward along the horizontal drawing grooves 490f, 490f of the block 490 in the Y-axis direction on the opposite sides to each other, and are connected to the lead connecting pieces 91a, 92a of the terminals 91, 92, respectively.

As shown in fig. 2E, the lead drawing portion 49 is composed of a lead drawing block (terminal block) 490 and a lead drawing table 491, and the lead drawing block 490 is provided with terminals 91 and 92. In the present embodiment, the terminals 91 and 92 are fixed (integrated) by being fitted into the lead drawing block 490 by insert molding or the like, but may be separately attached.

As shown in fig. 4A and 5A, the terminals 91 and 92 have lead connecting pieces 91a and 92 a. The lead connection pieces 91a and 92a are connected to the lead portions 22a and 22a of the inner coil 20 (first winding 22) or the lead portions 32a and 32a of the outer coil 30 (second winding 32) shown in fig. 2C. As shown in fig. 4A and 5A, the lead connecting pieces 91a and 92a have a substantially C-shape, and sandwich the lead portions 22a and 22a or the lead portions 32a and 32a drawn outward in the Y-axis direction.

As shown in fig. 4A and 5A, side extending pieces 91b and 92b are integrally connected to ends of the lead connecting pieces 91a and 92a in the X axis direction. The side extending pieces 91b and 92b extend outward in the Y axis direction (in a direction away from the bobbin 40) as viewed from the lead connecting pieces 91a and 92a, and the extending direction thereof substantially coincides with the extending direction of the lead portions 22a and 22a or the lead portions 32a and 32 a.

As shown in fig. 4A and 5A, upper extending pieces 91c and 92c are integrally connected to inner ends of the side extending pieces 91b and 92b in the Y axis direction (opposite to the side on which the lead connecting pieces 91a and 92a are arranged). The upper extension pieces 91c and 92c extend upward in the Z-axis direction and extend above the upper opening edge 330 of the housing 300. That is, a part of the upper extending pieces 91c and 92c extends above the upper opening edge 330.

The upper end of the upper extending pieces 91c, 92c in the Z-axis direction is integrally connected to the case transverse pieces 91d, 92 d. The housing cross-sections 91d, 92d extend from the center of the spool 40 toward the outside in the X-axis direction. A step corresponding to the height of the upper extending pieces 91c and 92c is formed between the case lateral pieces 91d and 92d and the side extending pieces 91b and 92 b. As shown in fig. 3, the housing cross-sections 91d, 92d extend across the inside and outside of the housing 300 in the X-axis direction, and cross (intersect or cross) the upper opening edge 330 of the housing 300, while extending from the inside of the housing 300 toward the outside above the upper opening edge 330. The case cross-sections 91d and 92d have a flat plate shape parallel to the X-Y plane, but may have a curved structure such as a curved surface.

As shown in fig. 4A and 5A, lower extending pieces 91e and 92e are integrally connected to outer end portions of the case transverse pieces 91d and 92d in the X axis direction. The lower extension pieces 91e and 92e have flat plate shapes parallel to the Y-Z plane and extend downward in the Z-axis direction. The lower extending pieces 91e and 92e have a longer shape than the upper extending pieces 91c and 92c in the Z-axis direction, and extend downward from the case cross-sectional pieces 91d and 92d outside the case 300 as shown in fig. 3.

The lower extending pieces 91e and 92e extend along the outer surface 310 of the housing 300, and extend downward from above the upper opening edge 330 of the housing 300 in the Z-axis direction.

As shown in fig. 4A and 5A, the lower ends of the lower extending pieces 91e and 92e in the Z-axis direction, i.e., the inner sides in the Y-axis direction, are integrally connected to outer protruding pieces 91f and 92 f. The outward projecting pieces 91f and 92f have flat plate shapes parallel to the X-Z plane and extend in the X-axis direction. As shown in fig. 3, the outward projecting pieces 91f and 92f extend in a direction away from the outer surface 310 of the case 300.

The distance in the Z-axis direction from the upper opening edge 330 of the case 300 to the outward projecting pieces 91f, 92f is determined by the length in the Z-axis direction of the downward extending pieces 91e, 92e, but the distance is not limited to the illustrated example and may be set longer. In the present embodiment, the outward projecting pieces 91f and 92f have flat plate shapes parallel to the X-Z plane, but may have flat plate shapes parallel to the X-Y plane or flat plate shapes that extend to a plane between the X-Z plane and the X-Y plane.

As shown in fig. 2E, the lead drawing platform 491 is formed integrally with the spool 40, and is disposed at each end in the X-axis direction of the flange portion 48 on the spool 40. An insulating wall 491e is formed between the lead drawing platform 491 and the flange portion 48 on the bobbin. The insulating wall 491e has a flat plate shape parallel to the Y-Z plane and abuts against the insulating plate portion 66 of the core housing 60. The upper end of the insulating wall 491e is positioned substantially at the same position as the upper end of the insulating plate 66. The insulating wall 491e is provided to insulate the core 12 from the lead portion 32A (or 22A) of the outer coil 30 (or the inner coil 20) when the core 12 shown in fig. 2A is mounted on the bobbin 40.

The insulating wall 491e is formed with a fixing recess 491f recessed toward the center of the bobbin 40. The fixing recess 491f is disposed between the pair of insulating plate portions 66 of the core cover 60, and the fixing recess 491f and the insulating plate portions 66 are disposed so as to be substantially flush with each other on the inner sides of the insulating plate portions 66.

A base center portion 491a and two base side portions 491b, 491b are formed at each end in the X axis direction of the bobbin upper flange portion 48. The base center portion 491a and the base side portions 491b have a shape extending outward in the X-axis direction from the bobbin upper flange portion 48, and have a substantially flat plate shape parallel to the X-Y plane. The base center 491a is disposed between the two base side portions 491b, 491 b.

A base drawing groove 491c is formed between the base side portion 491b and the base center portion 491 a. Similarly, a base leading groove 491c is formed between the other base side portion 491b and the base center portion 491 a. Lead portion 32a (or 22a) of outer coil 30 (or inner coil 20) can be inserted through base lead-out groove 491 c. The base lead-out groove 491c extends in the X-axis direction.

Lateral thin plate portions 491d are formed at the outer side ends of the base lateral portions 491b in the Y-axis direction. The side thin plate portions 491d extend in the X-axis direction, and the thickness of the side thin plate portions 491d is thinner than that of the base side portions 491 b. The groove 490i of the lead drawing block 490 to be described later engages with the side thin plate 491 d.

The lead drawing block 490 functions as a terminal block for fixing the terminals 91 and 92, and is formed separately from the bobbin 40 (lead drawing block 491). As a material constituting the lead drawing block 490, for example, a resin different from the bobbin 40, for example, a resin having better formability than the bobbin 40 or a resin having good heat dissipation properties may be selected. Specifically, for example, resin materials such as PET, PBK, PPS, and the like can be used.

As shown in fig. 5A, the lead drawing block 490 has a base 490a, and an engaging protrusion 490g is formed at a substantially central portion of the base 490a in the Y-axis direction. The engaging protrusion 490g protrudes from the inner end of the base 490a in the X-axis direction toward the center of the bobbin.

Two front wall portions 490b, 490b are formed on the inner end surface of the base 490a in the X axis direction so as to sandwich the engagement convex portion 490g therebetween. One front wall portion 490b is disposed on one side of the base 490a in the Y-axis direction, and the other front wall portion 490b is disposed on the other side of the base 490a in the Y-axis direction. The front wall portion 490b has a wall surface parallel to the Y-Z plane, and as shown in fig. 2E, the front surface of the front wall portion 490b abuts on the insulating wall 491E.

A fixing projection 490h is formed on the inner end surface of the front wall portion 490 b. The fixing projection 490h is located on the side of the inner end surface of the front wall portion 490b where the engaging projection 490g is arranged. The end surfaces of the front wall portions 490b on the inner sides of the fixing protrusions 490h abut against the end portions of the fixing recesses 491f formed in the insulating wall 491e of the lead-out platform 491 in the Y-axis direction. Thus, when the lead drawing block 490 is attached to the lead drawing table 491, the lead drawing block 490 can be prevented from being displaced in the Y-axis direction with respect to the lead drawing table 491.

A vertical drawing groove 490e is formed between the engaging protrusion 490g and the front wall 490 b. Similarly, a vertical drawing groove 490e is formed between the engaging protrusion 490g and the other front wall 490 b. The vertical lead groove 490e extends in the Z-axis direction, and the lead portion 32a (or 22a) of the outer coil 30 (or the inner coil 20) can be inserted along the vertical lead groove 490 e. The lead portion 32a (or 22a) is drawn upward in the Z-axis direction inside the vertical drawing groove 490 e. That is, the vertical lead groove 490e functions as a guide groove for guiding the lead portion 32a upward in the Z-axis direction in alignment with the base lead groove 491c of the lead platform 491.

A rear wall portion 490c extending from one side to the other side in the Y-axis direction is formed at the rear end (outside the bobbin) of the base 490a in the X-axis direction. As shown in fig. 5A, two terminal holes 490j are formed in the rear wall portion 490c at predetermined intervals in the Y-axis direction. The housing transverse slices 91d, 92d of the terminals 91, 92 are led out through the terminal holes 490 j.

A horizontal drawing groove 490f is formed between the rear wall portion 490c and the front wall portion 490 b. The horizontal lead groove 490f extends outward in the Y-axis direction, and the lead portion 32a (or 22a) of the outer coil 30 (or the inner coil 20) can be inserted along the horizontal lead groove 490 f. More specifically, the lead portion 32a drawn upward in the Z-axis direction along the vertical drawing groove 490e is bent in the Y-axis direction and drawn outward in the Y-axis direction along the horizontal drawing groove 490 f. That is, the horizontal lead groove 490f functions as a guide groove for guiding the lead portion 32a (or 22a) outward in the Y-axis direction.

Side wall portions 490d are formed at respective ends of the base 490a in the Y-axis direction. The side wall portion 490d has a wall surface parallel to the X-Z plane, and extends downward in the Z-axis direction from the base 490 a. The terminal hole 490j communicates with the side wall portion 490d, and the side extension pieces 91b and 92b of the terminals 91 and 92 are led out through the terminal hole 490 j.

The side wall portion 490d is formed with a groove 490 i. The groove 490i is formed on the Y-axis direction inner side of the side wall portion 490d and extends in the X-axis direction. The side thin-plate portions 491d (see fig. 2E) of the lead drawing-out base 491 are inserted into the recessed groove 490i while sliding, and the recessed groove 490i and the side thin-plate portions 491d are engaged with each other. Thus, the lead drawing block 490 can be fixed to the lead drawing table 491 with the lead drawing table 491 engaged with the lead drawing block 491. The side wall portion 490d may be formed to extend below the resin upper surface LS of the high heat conductive resin filled in the case 300 shown in fig. 3. In this case, the block 490 may contact the high thermal conductive resin filled in the case 300 to dissipate heat.

As shown in fig. 4A and 5A, the insulation protection portion 100 includes an inner extension portion 110, a case transverse portion 120, and an outer extension portion 130. The insulating protector 100 is interposed between the terminals 91 and 92 and the housing 300, and insulates the terminals 91 and 92 from the housing 300 (see fig. 3). In the present embodiment, the insulating protection portion 100 is formed separately from the lead drawing block 490, and is detachably held or fixed to the housing 300.

The insulating protection portion 100 is made of an insulating material. As a material constituting the insulating protection portion 100, a polyimide-based resin, a silicone-based resin, an epoxy-based resin, an acrylic-based resin, a polyether ether ketone-based resin, a polyether sulfone-based resin, a polyacetal-based resin, an aromatic polyamide-based resin, or the like can be used, and in addition, a resin having heat resistance (or elasticity) in addition to insulation or other members can be used.

The insulating protection portion 100 has a thin plate (flat plate) shape and is formed in a substantially C-shape. As shown in fig. 3, insulating protection unit 100 is attached to case 300 so as to straddle outer surface 310, inner surface 320, and upper opening edge 330 of case 300. The thickness of the insulation protection part 100 is preferably 0.5 to 1.0 mm. However, the thickness of the insulating protection portion 100 is not limited to the above thickness, and may be appropriately determined within a range that can effectively ensure insulation between the terminals 91 and 92 disposed on the front surface thereof and the housing 300 disposed on the rear surface thereof. The width of the insulating protection portion 100 in the Y axis direction is larger than the distance between the terminals 91 and 92 in the Y axis direction.

As shown in fig. 3 and 5A, the inner extension 110 has a flat plate shape parallel to the Y-Z plane and extends along the inner side surface 320 of the housing 300. The inner extension 110 abuts against the inner surface 320 of the housing 300. The length of the inside extension portion 110 in the Z-axis direction is appropriately determined within a range in which the insulating protector 100 can be reliably held (hooked) on the upper opening edge 330 of the housing 300. As shown in fig. 3, the inner extension 110 is preferably formed to extend downward from a resin upper surface LS of the high thermal conductive resin housed inside the case 300.

A housing transverse portion 120 is integrally connected to an upper end of the inner extension portion 110 in the Z-axis direction. The housing transverse portion 120 extends in the X-axis direction toward a direction away from the bobbin 40 (outside the bobbin 40). The housing transverse portion 120 extends in the X-axis direction in a manner to cross the inside and outside of the housing 300, and crosses (transects or crosses) the upper opening edge 330 of the housing 300 while extending from the inside of the housing 300 toward the outside on the upper surface of the upper opening edge 330.

The housing transverse section 120 has a flat plate shape parallel to the X-Y plane and abuts against the upper opening edge 330 of the housing 300. The housing transverse section 120 faces the housing transverse sections 91d, 92d of the terminals 91, 92. The length of the housing transverse portion 120 in the X axis direction is substantially equal to the length of the upper opening edge 330 of the housing 300 in the X axis direction. In the example shown in fig. 3, a predetermined gap is formed between the housing transverse section 120 and the housing transverse sections 91d and 92d of the terminals 91 and 92, but they may be in contact with each other.

An outer extension 130 is integrally connected to an outer end of the housing transverse portion 120 in the X axis direction. The outer extension 130 has a flat plate shape parallel to the Y-Z plane and extends downward in the Z-axis direction. The outer extension 130 abuts against the outer surface 310 of the housing 300. The outer extension 130 has a shape longer than the inner extension 110 in the Z-axis direction, and extends downward from the housing transverse portion 120 along the outer surface 310 of the housing 300.

The outer extension 130 faces the lower extension pieces 91e and 92e of the terminals 91 and 92. In the example shown in fig. 3, a predetermined gap is formed between the outer extending portion 130 and the lower extending pieces 91e and 92e, but they may be connected to each other.

The lower end of the outer extension 130 in the Z-axis direction is disposed at a position lower than the lower ends of the lower extension pieces 91e and 92e of the terminals 91 and 92 in the Z-axis direction. This can reliably achieve insulation between the lower extending pieces 91e and 92e and the outer surface 310 of the housing 300 via the outer extending portion 130.

In the present embodiment, the terminals 91 and 92 can form an insulating region in the upper portion of the housing 300 exposed from the lead-out portion 49 (lead-out block 490) by covering the housing transverse portion 120 and the outer extension portion 130 of the insulating protection portion 100.

The coil device 10 of the present embodiment is manufactured by assembling the components shown in fig. 2A to 2E and winding the windings 22 and 32 around the bobbin 40 and the bobbin cover 50. The coil device 10 of the present embodiment is housed inside the case 300, but the case 300 is not an essential component.

Next, an example of a method for manufacturing the coil device 10 will be described. In manufacturing the coil device 10, first, the bobbin 40 shown in fig. 2C is prepared. The material of the bobbin 40 is not particularly limited, but the bobbin 40 is formed of an insulating material such as resin.

Next, the first winding 22 is wound around the outer periphery of the first hollow cylindrical portion 44 of the bobbin 40 to form the inner coil 20. The first winding 22 for forming the inner coil 20 is not particularly limited, but a litz wire or the like is preferably used. In the inner coil 20, a flange-shaped coil portion 20a having an outer diameter larger than that of the other inner coil 20 portion is formed at the Z-axis lower end of the inner coil portion 20 by α -winding.

Next, the bobbin case 50 is attached to the bobbin 40 on which the inner coil 20 is formed. The second winding 32 constituting the outer coil 30 is wound around the outer periphery of the second hollow cylindrical portion 54 on the bobbin case 50. The flange-shaped coil part 20a is positioned inside the gap retaining piece 52a of the cover lower flange part 52 on the bobbin cover 50. That is, the first sub-winding portion 45b shown in fig. 3 is located inside the gap retaining piece 52a of the cover lower flange portion 52.

The lead portions 22a, 32a are inserted into the base drawing grooves 491c of the lead connecting base 491, and then the lead drawing blocks 490, 490 are slidably moved from the outside in the X-axis direction and attached to the base 491.

Thereafter, the core cover 60 shown in fig. 2C is attached to both sides of the bobbin cover 50 in the Y-axis direction, and then the core 12 is attached from the up-down direction in the Z-axis direction. That is, the front ends of the center legs 14, 14 and the front ends of the side legs 16, 16 of the core 12 are brought close to each other. Further, a gap may be provided between the front ends of the middle legs 14, 14.

The material of each core 12 is not particularly limited, and examples thereof include soft magnetic materials such as metal and ferrite. The core 12 may be fixed to the bobbin case 50 and the bobbin 40 by being bonded with an adhesive or wound around a belt-like member at the outer periphery, or may be attached only to the bobbin case 50 and the bobbin 40. In the present embodiment, as shown in fig. 1, most of the coil device 10 assembled in this manner is housed inside a case 300.

As shown in fig. 3, a highly thermally conductive resin such as potting resin is filled in the case 300 to a position of the resin upper surface LS in a state where the coil device 10 is housed. The resin upper surface LS is preferably located below the opening edge portion 330 on the upper side of the housing 300 in the Z-axis direction and close to the lower surface of the bobbin upper flange portion 48 of the bobbin 40. The Z-axis gap between the resin upper surface LS and the opening edge 330 on the upper side of the housing 300 is preferably 3mm to 10 mm.

The core 12 may be arranged such that the heat dissipation plates 80 are in contact with the upper surface of the core 12 and the side surfaces in the Y axis direction, and the side legs extending downward from both ends in the Y axis direction of each heat dissipation plate 80 are impregnated in the highly conductive resin stored in the case 300. With this configuration, heat from the upper portion of the core 12 is transferred to the high heat conductive resin stored inside the case 300, and heat dissipation can be efficiently achieved. The heat sink 80 is preferably made of a high thermal conductive material such as a metal such as aluminum.

It is preferable to fill the inside of the case 300 with the high thermal conductive resin before the coil device 10 is housed inside the case, but the filling of the resin may be performed after the coil device 10 is housed inside the case.

The coil device 10 of the present embodiment can be used as a vertical coil device in which the winding axis of the coil is arranged perpendicular to the surface of the mounting substrate, and therefore, the core 12 inserted into the hollow portion of the bobbin 40 is easily cooled.

In addition, in the present embodiment, as shown in fig. 2C, the spool cover 50 can be divided by the dividing connection portion 53 parallel to the winding shaft, and therefore, the spool cover 50 can be easily disposed on the outer periphery of the spool 40.

As shown in fig. 3, in the coil device 10 of the present embodiment, since the winding wire 22 is wound such that each winding area 47 has only a single winding portion along the winding axis direction, it is easy to prevent variations in the number of windings of each layer of the winding wire 22 in the radial direction, and this contributes to stabilization of the leakage characteristics (inter-coil coupling). That is, it is easy to strictly control the coupling coefficient between the outer coil 30 constituting the secondary coil and the inner coil 20 constituting the primary coil, and the coil device 10 of the present embodiment can be suitably used as a leakage transformer.

In the present embodiment, as shown in fig. 2C, the spool cover 50 includes gap retaining pieces 52a intermittently at the outer edge of the cover lower flange portion 52. Therefore, as shown in fig. 3, the flange-shaped coil portion 20a having a large number of radially wound layers is easily formed at the lower end portion of the first coil 20 in the Z-axis direction.

In the present embodiment, as shown in fig. 2D, the insulating plate 200 is attached to one end of the bobbin case 50 in the X axis direction. Therefore, the lower lead portion 22a of the first winding 22 constituting the inner coil 20 is easily taken out from under the cover lower flange portion 52 of the cover 50, and is guided to the lead take-out table 491 while insulation from the outer coil 30 is secured.

In the present embodiment, as shown in fig. 3, a flow gap is uniformly formed between the outer peripheral edge of the winding partition wall flange 46 and the inner peripheral surface of the bobbin case 50. With this configuration, the distance between the coils 20 and 30 of the wire wound on the inner and outer sides of the bobbin case 50 is easily made constant, and the variation in the coil characteristic values is reduced.

In particular, in the coil device 10 of the present embodiment, as shown in fig. 2C, the bobbin case 50 has the gap retaining piece 52a, and the gap retaining piece 52a has the opening 52b or the notch. Therefore, through the opening 52b or the slit, a highly thermally conductive resin such as a potting resin enters the inside of the bobbin case 50 and enters between the bobbin case 50 and the bobbin 40. As a result, the first winding 22 wound around the first winding portion 45 of the bobbin 40 is in contact with the highly thermally conductive resin, and the heat from the first winding 22 is transferred to the highly thermally conductive resin, thereby dissipating the heat well. Therefore, in the coil device 10 of the present embodiment, heat dissipation is excellent even if the coil device 10 is downsized.

In the present embodiment, as shown in fig. 2C, the spool cover 50 includes a cover lower flange portion 52 and a cover upper flange portion 58. Further, a gap holding piece 52a is provided below the cover lower flange portion 52. A cover flange 58 is disposed axially below the bobbin upper flange 48, and an outlet gap capable of discharging air inside the bobbin cover 50 to the outside is formed between the bobbin upper flange 48 and the cover flange 58. The outlet gap is formed by the upper flange portion 58a, the stepped convex portions 58g and 58h, and the stopper convex portion 58i formed on the upper surface of the cover upper flange portion 58 coming into contact with the lower surface of the bobbin upper flange portion 48.

With this configuration, when the high thermal conductive resin enters the inside of the bobbin case 50 from below the case lower flange portion 52, the air located inside the bobbin case 50 is easily discharged from the outlet gap, and the resin flows more smoothly.

In the present embodiment, the first winding 22 disposed on the inner peripheral side is a primary coil of a transformer, but may be a secondary coil (inner coil 20) on which a high voltage is further applied. In this case, the secondary coil (inner coil 20) on which a high voltage acts is disposed inside the primary coil (outer coil 30) on which a lower voltage acts, thereby facilitating insulation.

In the coil device 10 of the present embodiment, the terminals 91 and 92 include the case cross-sectional pieces 91d and 92d and the lower extending pieces 91e and 92 e. Therefore, the terminals 91 and 92 extend to the side of the housing 300 (in the direction along the extending direction of the housing transverse slices 91d and 92 d) rather than to the upper side of the housing 300, and it is not necessary to provide a terminal block (lead-out block 490) for fixing the terminals 91 and 92 to the upper side of the housing 300. Therefore, most of the coils 20 and 30 and the core 12 can be housed inside the case 300, and the case 300 is filled with a heat dissipating resin (high thermal conductive resin), so that most of the coils 20 and 30 and the core 12 are immersed in the heat dissipating resin, whereby heat of the coils 20 and 30 and the core 12 can be sufficiently dissipated through the heat dissipating resin.

In the coil device 10 of the present embodiment, as described above, since the terminal block (lead drawing block 490) does not need to be provided above the case 300, the height of the coil device 10 can be suppressed, and the height of the coil device 10 can be reduced.

In the coil device 10 of the present embodiment, since the lower extending pieces 91e and 92e are provided on the terminals 91 and 92, it is not necessary to draw the terminals 91 and 92 to the outside lower side of the case 300 by providing, for example, a notch or the like to the lower side of the case 300. Therefore, when the case 300 is filled with the heat dissipating resin, a sufficient amount of the heat dissipating resin is filled into the case 300 without causing leakage of the heat dissipating resin from the notches or the like, and the heat of the coils 20 and 30 and the core 12 can be efficiently dissipated via the heat dissipating resin.

In the present embodiment, the terminals 91 and 92 have outward projecting pieces 91f and 92 f. Therefore, the outward projecting pieces 91f and 92f can be used as the user terminals.

The coil device 10 of the present embodiment includes an insulating protection portion 100. Therefore, the terminals 91 and 92 can be pulled out to the side of the housing 300 while preventing short-circuit failure between the terminals 91 and 92 and the housing 300 via the insulating protection portion 100.

In the present embodiment, the insulation protection portion 100 includes a housing transverse portion 120 and an outer extension portion 130. Therefore, the terminals 91 and 92 can be insulated from the upper opening edge 330 of the housing 300 by the housing transverse portion 120, and the terminals 91 and 92 can be insulated from the outer surface 310 of the housing 300 by the outer extension portion 130.

In the present embodiment, the lead drawing block 490 is provided, and the insulating protection portion 100 is formed separately from the lead drawing block 490. Therefore, the structure of the lead drawing block 490 or the insulating protection portion 100 can be simplified, and the lead drawing block 490 or the insulating protection portion 100 can be easily formed.

In the present embodiment, the lead drawing block 490 is formed separately from the bobbin 40. Therefore, when the specification of the lead drawing block 490 is changed, the lead drawing block 490 according to the specification may be prepared and attached to the spool 40. That is, the design of the entire bobbin does not need to be changed, and the bobbin can be flexibly adapted to the specification change.

As shown in fig. 3, in the coil device 10 of the present embodiment, the adjustment of the inter-coil coupling can be realized by the radial gap between the inner coil portion 20 of the first winding 22 wound around the first main winding portion 45a and the outer coil portion 30 of the second winding 32 wound around the second winding portion 55. In the coil device 10 of the present embodiment, the inter-coil coupling can be adjusted by the gap in the Z-axis direction between the flange-shaped coil portion 20a of the first winding 22 wound around the first sub-winding portion 45b and the outer coil portion of the second winding 32 wound around the second winding portion 55.

Further, if the number of winding layers of the first wire 22 wound around the first sub-winding portion 45b is increased, the overlapping area of the flange-shaped coil portion 20a and the outer coil portion 30 as viewed in the axial direction is also increased, and the leakage characteristic can be adjusted. As described above, in the coil device 10 of the present embodiment, the leakage characteristics can be adjusted by both the radial gap and the axial gap.

In the coil device 10 of the present embodiment, the number of winding layers of the first wire 22 wound around the first sub-winding portion 45b of the first winding portion 45 is increased, so that the total number of turns of the first wire 22 can be increased, and the axial dimension of the bobbin 40 can be shortened. Therefore, the height of the coil device 10 can be reduced.

In the present embodiment, the outermost layer of the flange-like coil portion 20a wound around the first sub-winding portion 45b is located outside the cylindrical wall of the second winding portion 55. With this configuration, the flange-shaped coil portion 20a and the outer coil portion 30 overlap each other when viewed from the axial direction. Therefore, the leakage characteristic can be easily adjusted by the axial gap between the flange-like coil portion 20a of the first wire 22 wound around the first sub-winding portion 45b and the outer coil portion 30 of the second wire 32 wound around the second winding portion 55.

In the present embodiment, the partition wall flanges 46 are formed at predetermined intervals in the Z-axis direction in the first winding portion 45. With this configuration, the α winding of the first winding 22 is facilitated. Further, a partition projecting piece 46d (see fig. 2C) as a projecting portion projecting outward beyond the outer edge end of the winding partition flange 46 formed in the range of the first main winding portion 45a is formed on the winding partition flange 46 that partitions the first main winding portion 45a and the first sub-winding portion 45 b. The separation tab 46d may function as a location for the spool cover 50.

In the present embodiment, the gap retaining pieces 52a are intermittently formed along the circumferential direction at the outer peripheral edge of the cover lower flange portion 52 of the bobbin cover 50, the first sub-winding portion 45b is positioned inside the gap retaining pieces 52a, and the flange-shaped coil portion 20a is formed inside the gap retaining pieces 52 a. With this configuration, the plurality of turns of the first winding 22 can be easily wound around the outer periphery of the first sub-winding portion 45 b.

In the present embodiment, the first winding 22 is wound continuously around the first main winding portion 45a and the first sub-winding portion 45b by α. By adopting the α winding, the first winding 22 can be easily wound, and the axial length of the inner coil 20 formed by the first winding 22 can be shortened. In addition, it is easy to wind the multi-turn first winding 22 around the outer periphery of the first sub-winding portion 45 b.

Second embodiment

The coil device 10A of the second embodiment shown in fig. 1B and 5B has the same configuration as the coil device 10 of the first embodiment except for the following points, and exhibits the same operational effects. In fig. 1B and 5B, components common to those of the coil device 10 of the first embodiment are denoted by common reference numerals, and a part of the description thereof is omitted.

The coil device 10A of the present embodiment includes an insulating protection portion 100A. If fig. 5A and 5B are compared, it is understood that the insulating protection portion 100A of the present embodiment is different from the insulating protection portion 100 of the first embodiment in that it is integrally formed with the lead drawing block 490. The insulating protection portion 100A and the lead drawing block 490 are integrally formed by injection molding or the like.

As shown in fig. 5B, insulating protection portion 100A has a substantially L-shape, and includes case transverse portion 120A and outer extension portion 130A. On the other hand, the insulating protection section 100A does not have a structure corresponding to the inner extension 110 of the first embodiment shown in fig. 5A. In the present embodiment, as shown in fig. 5B, the insulating protection portion 100A is integrated with the lead drawing block 490, and the rear wall portion 490c of the lead drawing block 490 functions similarly to the inner extension 110 shown in fig. 5A.

As shown in fig. 5B, the housing transverse section 120A is formed thicker than the housing transverse section 120 of the first embodiment shown in fig. 5A, and the housing transverse sections 91d, 92d of the terminals 91, 92 are housed therein. That is, in the present embodiment, the case transverse slices 91d and 92d are fitted into the case transverse cutting portion 120A and are not exposed to the outside. The inner end of the case transverse portion 120A in the X axis direction is integrally connected to the upper end of the rear wall portion 490c of the lead drawing block 490 in the Z axis direction. The lower surface of the housing transverse portion 120A abuts against the upper opening edge 330 of the housing 300.

The outer extension 130A is formed thicker than the outer extension 130 of the first embodiment shown in fig. 5A, and the lower extension pieces 91e and 92e of the terminals 91 and 92 are housed inside. That is, in the present embodiment, the lower extending pieces 91e and 92e are fitted into the inside of the outer extending portion 130A and are not cut out and exposed to the outside. On the outer end surface of the outer extension 130A in the X axis direction, two terminal holes 131, 131 are formed at a predetermined interval in the Y axis direction. The outward projecting pieces 91f, 92f of the terminals 91, 92 are led out through the terminal holes 131, 131. The inner end surface of the outer extension 130A in the X axis direction abuts against the outer surface 310 of the housing 300.

Insulating protection portion 100A is mounted on case 300 with outer extension 130A and rear wall portion 490c of lead extraction block 490 interposed between the upper end of case 300.

In the present embodiment, the same effects as those of the first embodiment can be obtained. In the present embodiment, the insulating protection portion 100A is formed integrally with the lead drawing block 490. Therefore, in the manufacturing process of the coil device 10A, the process of separately mounting the insulating protection portion 100A to the case 300 (as a single body) can be omitted, and the manufacturing of the coil device 10A becomes easy.

In the present embodiment, the insulating protection portion 100A is integrally formed with the terminals 91 and 92. For example, the terminals 91 and 92 are integrally formed with the insulating protection portion 100A by insert molding or the like, thereby facilitating the manufacture of the coil device 10A.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention.

For example, in the above-described embodiment, as shown in fig. 3, the first sub-winding portion 45b is formed below the first main winding portion 45a in the Z-axis direction, and the flange-shaped coil portion 20a is formed below the inner coil 20, but the opposite may be applied. That is, the first sub-winding portion 45b may be formed in the Z-axis direction of the first main winding portion 45a, and the flange-shaped coil portion 20a may be formed above the inner coil 20. In the present embodiment, since cooling is performed from the lower side of the case 300, the flange-shaped coil portion 20a having the large number of winding layers in the radial direction has good heat dissipation when positioned on the lower side.

The first winding 22 need not be wound with α, but may be wound in parallel. The effect of the present invention can be expected even if the winding is arranged. The specific shape of the bobbins 40 and 40a and the specific shape of the core 12 are not limited to the above-described embodiments, and various modifications may be made. In addition, the coil device of the present invention can also be used for a reactor or the like as applications other than, for example, a transformer for a charger.

In the above embodiments, the shape of the insulating protection portions 100 and 100A may be appropriately changed. For example, in fig. 5A, the insulating protection portion 100 including the case transverse portion 110 and the outer extension portion 130 may be configured by omitting the inner extension portion 100 from the insulating protection portion 100. In fig. 5B, the insulating protection portion 100A and the lead extraction block 490 may be separated from each other.

In each of the above embodiments, the coil devices 10 and 10A may be provided with two insulating protection units 100 and 100A, the terminal 91 and the case 300 may be insulated by the insulating protection units 100 and 100A, and the terminal 92 and the case 300 may be insulated by the other insulating protection unit 100 and 100A.

In this case, the shape of the insulating protection portions 100 and 100A may be substantially identical to the shape of the case transverse slices 91d and 92d and the lower extension slices 91e and 92e of the terminals 91 and 92.

Description of the symbols

10. 10A coil device

12 core

13 base

14 middle foot

16 side foot

20 inner coil

20a flange-shaped coil part

22 first winding

22a lead part

30 outer coil

32 second winding

32a lead part

40 bobbin (Transformer frame/bobbin)

42 bobbin base plate

42a foot part

44 first hollow cylinder part

44a first through-hole

44b separation projection

45 first winding part

45a first main winding part

45b first sub-winding part

46 wrap around bulkhead flange

46a connecting groove

46b, 46c cut edge

46d separation tab (convex part)

46e flow-through gap

47 winding division

48 flange part on spool

48a step part

48b positioning recess

48c engaging projection

49 lead wire leading part

490 lead-out block (terminal block)

490a base

490b front wall

490c rear wall

490d side wall portion

490e vertical lead-out groove

490f horizontal lead-out groove

490g engaging protrusion

490h fixing convex part

490i groove

491 lead drawing-out table

491a central part of the base

491b side parts of the base

491c base lead-out groove

491d side thin plate part

491e insulating wall

491f fixing concave part

50 spool cover

50a, 50b half body

52 cover lower flange part

52a gap maintaining piece (non-winding part)

52b opening part

53 divided joint

53a inner connecting sheet

53b outside connecting sheet

54 second hollow cylinder

55 second winding part

58 cover upper flange part

58a are connected to the upper flange part

58b connect the lower flange part

58c, 58d engaging part

58e, 58f engaging surfaces

58g, 58h step convex part

58i stop lug

60 core cover

62 cover body

62a divided piece

64 mounting flange

64a protruding piece

64b opening part

66 insulating plate part

66a engaging projection

70 lead-out block cover

71 roof plate part

72 side wall portion

73 rear wall

74 recess

80 radiator plate

91. 92 terminal

91a, 92a lead connecting sheet

91b, 92b side extension piece

91c, 92c upper extension piece

91d, 92d Shell Cross-section

91e, 92e lower extension piece

91f, 92f outward projecting piece

100. 100A insulation protection part

110 inner side extension part

120. 120A shell crosscut

130. 130A outer extension part

200 insulating plate

210 plate body

220 board top board

230 outward protruding sheet

240 wire path

300 casing

305 frame body

310 lateral surface

320 medial side

315. 330 opening edge

340 bottom plate

Above the LS resin.

Claims (9)

1. A coil device having:

a bobbin having a first winding portion for winding a first winding wire around an outer periphery thereof; and

a spool cover that covers a periphery of a spool around which the first winding wire is wound,

the spool cover includes a second winding portion for winding a second winding different from the first winding around an outer periphery thereof, and a non-winding portion disposed at a lower position or an upper position along an axial direction of the second winding portion,

the number of sub-winding layers of the first winding wound around the first sub-winding portion of the first winding portion located inside the non-winding portion is larger than the number of main winding layers of the first winding wound around the first main winding portion of the first winding portion located inside the second winding portion.

2. The coil device according to claim 1,

the position of the outermost layer of the first winding wound around the first sub-winding section is located outside the cylinder wall of the second winding section.

3. The coil device according to claim 1 or 2,

the first winding wire wound around the first sub-winding portion and the second winding wire wound around the second winding portion overlap each other when viewed in the axial direction.

4. The coil device according to claim 1,

a winding partition wall flange is formed at the first winding portion at a predetermined interval in the axial direction,

a winding partition flange that separates the first main winding portion from the first sub-winding portion is formed with a projection that projects outward beyond an outer edge end of the winding partition flange formed in the range of the first main winding portion.

5. The coil device according to claim 4,

the projection forms a notch that forms a flow gap that penetrates in the axial direction.

6. The coil device according to claim 1,

the spool cover has:

a second hollow tube portion that constitutes the second wound portion; and

a pair of cover flange portions formed at both ends of the second hollow tube portion in the axial direction,

a plurality of gap retaining pieces constituting the non-winding portion are intermittently formed along a circumferential direction on an outer periphery of at least any one of the cover flange portions,

the first sub-wound portion is located inside the gap retaining sheet.

7. The coil device according to claim 6,

the gap retaining piece is provided with an opening portion connecting the outer side and the inner side of the gap retaining piece.

8. The coil device according to claim 1,

the first winding wire is wound around the first main winding portion and the first sub-winding portion α.

9. The coil device according to claim 1,

the bobbin case further includes a case that contains the high thermal conductive resin so that the first winding portion of the bobbin and the second winding portion of the bobbin case are filled with the high thermal conductive resin.

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