JP7168902B2 - Bobbin and coil device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a coil device that can be suitably used as a transformer, for example, and a bobbin used therefor.

For example, the bobbin shown in Patent Document 1 is known as a bobbin used for transformers. In this conventional bobbin, a gap is formed between a pair of collars into which only one wire can be inserted, enabling multi-layer winding between the collars.

However, in the conventional bobbin, a large number of collars are formed in the winding axis direction, each collar is provided with a communication groove, and the wire is stretched between the collars so that the wire is wound around the outer periphery of the bobbin many times along the winding axis direction. It has been found that a problem arises when trying to wind the . That is, in the conventional bobbin, since the connecting grooves formed in each collar are generally formed in a straight line along the direction of the winding shaft, the crossing portion of the wire at the connecting groove portion is the winding shaft. There is a problem that it overlaps in the direction and deforms the collar.

This problem does not occur if the gap between adjacent flanges is made larger than the diameter of the wire to be wound, but in that case, the wire winding tends to be disturbed, and the inductance Variation in coil characteristic values such as In addition, if the gap between adjacent flanges is made small in order to prevent wire winding disorder, the wire crossing portion swells at the connecting groove, which may make it difficult to attach the wire cover in close contact with the outside thereof. There is also

That is, it becomes difficult to keep the distance between the wire (coil) wound outside the wire cover and the wire (coil) wound inside the wire cover constant, and the coupling coefficient between the coils decreases. , may vary. Moreover, it becomes difficult to reduce the size of the coil device.

JP 2008-66539 A

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and its object is to provide a coil device that can be miniaturized, has little wire winding disturbance, and has small variations in coil characteristic values, and a bobbin suitable for it. That is.

In order to achieve the above object, the bobbin according to the present invention is
A bobbin having an outer periphery around which a wire is wound,
A plurality of winding partition ribs are formed on the outer peripheral portion of the bobbin for separating adjacent wire winding portions along the winding axis of the wire for each winding section,
At least one connecting groove is formed in each of the winding partition ribs for connecting adjacent winding sections,
The circumferential position of at least one of a pair of notched edges formed in the winding partition rib so as to define the circumferential width of each of the communication grooves is adjacent along the winding axis direction. Different between the winding bulkhead collars.

In the bobbin according to the present invention, the circumferential position of at least one of the pair of cutout edges formed in the winding partition rib so as to define the circumferential width of the communication groove is aligned along the winding shaft direction. between adjacent winding partition collars. Therefore, even if the wire is wound in two or more layers in each winding section, the circumferential positions of the intersections of the wires passing through the connecting grooves that are adjacent along the winding axis direction cannot be shifted along the circumferential direction. becomes possible.

That is, in the bobbin of the present invention, even if the wire is wound in two or more layers in each winding section, there is no bulge or winding disturbance due to the wire intersection near the connecting groove, and the variation in the coil characteristic value is also reduced. Also, the size of the coil device can be easily reduced.

Circumferential widths of the communication grooves adjacent to each other along the winding axis direction may be different from each other. Moreover, the circumferential width of the communication groove may increase from the center toward the outside along the direction of the winding shaft.

Alternatively, one of the pair of cutout edges formed on each of the winding partition ribs may be located at a circumferential position extending upward from the center along the direction of the winding shaft. may be
Even if the circumferential position of the other side of the pair of notch edges formed in each of the winding partition ribs is at a position that spreads downward from the center along the winding axis direction. good.

By configuring in this way, particularly when the wire is α-wound from the central portion of the bobbin in the winding axis direction, it becomes easy to displace the wire crossing portion in the circumferential direction along the winding axis direction in the communication groove. .

A circumferential width of the communication groove may be substantially the same along the winding axis direction. However, it is necessary that the circumferential position of at least one of the pair of cutout edges be different between the winding partition rib collars adjacent along the winding axis direction. The communication groove may be obliquely formed in the outer peripheral portion of the bobbin.

A coil device according to the present invention includes:
a bobbin as described above;
a first wire wound around the outer periphery of the bobbin;
a wire cover that surrounds the bobbin around which the first wire is wound;
and a second wire wound around the outer periphery of the wire cover.

In the coil device of the present invention, even if the first wire is wound in two or more layers in each winding section, the circumferential positions of the intersections of the wires passing through the connecting grooves that are adjacent along the winding axis direction are It is possible to shift along the direction. That is, in the coil device of the present invention, even if the first wire is wound in two or more layers in each winding section, there is no bulge or winding disturbance due to the intersection of the wire near the communication groove, and the coil characteristic value does not vary. become smaller. Also, the size of the coil device can be easily reduced. The coil formed by the first wire may be the primary wire or the secondary wire.

A winding restricting collar for forming a non-winding section in which the first wire is not wound may be formed at the upper end or the lower end of the outer peripheral portion of the bobbin in the winding axis direction. Further, a positioning portion for positioning and attaching the wire cover to the bobbin may be formed on the outer peripheral portion of the bobbin located in the non-winding section. Forming the positioning portion facilitates the positioning of the bobbin and the wire cover.

Positioning that defines that the second wire is wound along the winding axis within a predetermined length range, including positions corresponding to the non-winding sections, on the outer peripheral portion of the wire cover. A collar portion may be formed. By configuring in this way, it is possible to position the wound portion of the second wire outside the non-wound section where the first wire is not wound, for example, to adjust the leakage characteristics of the coil device. become easier.

A passage concave portion may be formed in the inner peripheral portion of the wire cover for pulling out the lead portion of the first wire upward in the direction of the winding shaft. By doing so, the size of the coil device can be reduced.

Preferably, the outer peripheral edge of the winding partition brim can contact the inner peripheral portion of the wire cover at portions other than the positions of the passage concave portion and the communication groove. By configuring in this way, the distance between the coils of the wire wound on the inside and the outside of the wire cover can be easily made constant, and variations in the coil characteristic values can be reduced.

A deflecting protrusion is formed on the outer peripheral portion of the wire cover for hooking the lead portion of the second wire wound around the lower end portion in the winding axis direction and directing the lead portion upward in the winding axis direction. may By configuring in this way, it becomes easier to form the terminal block on the upper part of the bobbin in the direction of the winding shaft.

The coil device of the present invention is particularly effective when the first wire is wound in two or more layers on the winding section. Moreover, it is particularly effective when the width of the winding section in the winding axis direction is set to a width that allows the single first wire to enter, and winding disorder can be effectively prevented.

FIG. 1 is a perspective view of a coil device according to one embodiment of the present invention. 2A is an exploded perspective view of the coil device shown in FIG. 1. FIG. FIG. 2B is a perspective view of the bobbin with the wire cover shown in FIG. 2A exploded. 3A is a perspective view for winding a wire on the bobbin shown in FIG. 2B. FIG. FIG. 3B is a left side view of the bobbin shown in FIG. 3A. FIG. 3C is a front view of the bobbin shown in FIG. 3A. FIG. 3D is a cross-sectional view of the essential parts taken along line IIID--IIID shown in FIG. 3C. FIG. 3E is a left side view of a modification of the bobbin shown in FIG. 3B. FIG. 4A is a perspective view of the bobbin after wire winding shown in FIG. 2B as seen from the opposite direction of the X-axis. FIG. 4B is a left side view of the bobbin shown in FIG. 2B. 4C is a left side view showing a modification of the bobbin shown in FIG. 4B. FIG. FIG. 4D is a left side view showing a comparative example of the bobbin shown in FIG. 4B. FIG. 5 is a perspective view from a different angle of the coil cover shown in FIG. 2B. FIG. 6A is a cross-sectional view of the main part taken along line VIA-VIA shown in FIG. 1A. FIG. 6B is a cross-sectional view of the essential part along line VIB--VIB shown in FIG. 1A.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described based on embodiments shown in the drawings.
1st embodiment
As shown in FIG. 1, a coil device 10 according to one embodiment of the present invention has four cores 12, a bobbin 40, a wire cover 50 and two core covers 60. As shown in FIG. In this embodiment, the X-axis, Y-axis, and Z-axis are perpendicular to each other, and the Z-axis is perpendicular to the mounting surface of the coil device 10 . The direction in which the lead-out portions 49 of are positioned opposite to each other is the X-axis.

As shown in FIG. 2A, the four cores 12 are assembled to form a magnetic path through which the magnetic flux generated by the coils described below passes. These cores 12 have symmetrical shapes and are connected to each other so as to sandwich the wire cover 50 and the bobbin 40 from above and below (the Z-axis direction in the figure).

Each core 12 has a substantially E-shaped longitudinal section (a cross section including the Y-axis and the Z-axis). Each core 12 is made of a soft magnetic material such as ferrite or a metal magnetic material. It has side legs 16 , 16 and a middle leg 14 projecting in the Z-axis direction from an intermediate position in the Y-axis direction of each base 13 .

In this embodiment, the middle leg 14 of each core 12 is inserted into the first through hole 44a formed in the first hollow cylindrical portion 44 of the bobbin 40, and formed in the inner peripheral wall of the first hollow cylindrical portion 44. A gap is formed between the cores 12, 12 adjacent to each other in the X-axis direction by a certain separation convex portion 44b. A heat-dissipating resin, which will be described later, enters this gap, thereby improving the heat-dissipating property of the heat generated inside the coil device 10 .

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

As shown in FIG. 2B, the bobbin 40 has a substantially elliptical flat bobbin substrate 42 at its lower end in the Z-axis direction. As shown in FIGS. 3A to 3D, a first hollow cylindrical portion 44 is integrally formed on the substantially central portion of the bobbin substrate 42 so as to extend upward in the Z-axis direction.

As shown in FIG. 3A, a bobbin upper collar portion 48 is integrally formed on the upper portion of the first hollow cylindrical portion 44 in the Z-axis direction so as to protrude radially from the first hollow cylindrical portion 44 on the Y-axis-X-axis plane. There is. At both ends of the bobbin upper collar portion 48 in the X-axis direction, lead pull-out portions 49 are formed integrally.

As shown in FIG. 2B, one lead lead-out portion 49 is a common lead portion in which a pair of lead portions 22a, 22a, which are both ends of the first wire 22 constituting the inner coil 20, are commonly led out in the upward direction of the Z axis. It has a pedestal 49c in which a lead-out groove 49a is formed. The pedestal 49c is formed with individual lead-out grooves 49b leading to the opposite side in the Y-axis direction above the common lead-out groove 49a in the Z-axis direction. Each lead portion 22a, 22a is guided by each individual lead-out groove 49b. Terminals (not shown) are connected to the ends of the lead portions 22a, 22a. The terminal may be embedded and integrated with the pedestal 49c.

The other lead extraction portion 49 shown in FIG. 2B is a common extraction groove 49a from which a pair of lead portions 32a, 32a, which are both ends of the second wire 32 constituting the outer coil 30, are commonly extracted in the upward direction of the Z axis. is formed on the pedestal 49c. The pedestal 49c is formed with individual lead-out grooves 49b leading to the opposite side in the Y-axis direction above the common lead-out groove 49a in the Z-axis direction. The lead portions 32a, 32a are guided by the individual lead-out grooves 49b. Terminals (not shown) are connected to the ends of the lead portions 32a, 32a. The terminal may be embedded and integrated with the pedestal 49c.

Insulating walls 49d are formed on the respective lead-out portions 49 so as to rise from the boundaries between the bases 49c and the first hollow cylindrical portions 44 in the Z-axis upward direction. The insulating wall 49d can improve the insulating distance between the lead portion 22a or 32a and the cores 12, 12 shown in FIG.

As shown in FIGS. 3A to 3C, a first winding portion 45 is formed on the outer peripheral portion of the first hollow cylindrical portion 44 located between the bobbin upper collar portion 48 and the bobbin base plate 42 . In the first winding portion 45, as shown in FIG. 6B, a plurality of winding partition ribs 46 separate adjacent wire winding portions along the winding axis (Z-axis) of the first wire 22. It is formed integrally with the first hollow cylindrical portion 44 substantially parallel to the bobbin base plate 42 (and the bobbin upper collar portion 48) at predetermined intervals along the winding axis. The details of the winding partition brim 46 and the winding method of the first wire 22 will be described later.

The bobbin base plate 42, the first hollow cylinder portion 44, the bobbin upper flange portion 48, the lead lead-out portion 49, and the winding partition flange portion 46 of the bobbin 40 are preferably integrally formed by injection molding or the like.

A first through hole 44a is formed inside the first hollow cylindrical portion 44 of the bobbin substrate 42 so as to penetrate in the Z-axis direction. The middle leg 14 of the core 12 enters the first through-hole 44a from above and below in the Z-axis direction, and the tip of the middle leg 14 abuts against the substantially central portion of the through-hole 44a in the Z-axis direction. . In addition, as shown in FIG. 6B, a gap is formed at a predetermined interval so that the tips of the middle legs 14 inserted from above and below the Z-axis do not contact each other at the substantially central portion of the through-hole 44a in the Z-axis direction. good too.

As shown in FIG. 2B, the wire cover 50 is composed of a pair of half-split bodies 50a and 50b that can be split in the X-axis direction. , and in the combined state, the second winding portion 55 is formed on the outer peripheral portion of the cover 50 . After the inner coil 20 is formed by winding the first wire 22 around the first winding portion of the bobbin 40 , the wire cover 50 is attached to the outer periphery of the bobbin 40 and combined at the split connection portion 53 .

The wire cover 50 has a second hollow tubular portion 54 that covers the inner coil 20 from the outside. A wire cover lower flange portion 52 and a wire cover upper flange portion 58 are arranged on the outer peripheral portion of the second hollow tubular portion 54 so as to extend along the Z axis. It is formed along the circumferential direction at predetermined intervals in the direction. The lower collar portion 52 and the upper collar portion 58 are provided parallel to the plane of the XY axis and extend parallel to the installation surface.

A second winding portion 55 is provided between the lower collar portion 52 and the upper collar portion 58, and the second wire 32 that constitutes the outer coil 30, which is, for example, a secondary coil, is attached to the second winding portion 55. Alignment winding (or α winding) is performed. Alignment winding is a normal winding method in which the wire is wound from one end of the winding shaft toward the other end. The α winding will be described later.

As shown in FIG. 2A, a pair of core covers 60 are attached from both sides in the Y-axis direction to the outer periphery of the second winding portion 55 of the wire cover 50 to which the outer coil 30 is attached. The core cover 60 is made of an insulating material such as synthetic resin, and has a cover body 62. Its outer peripheral surface serves as a guide surface for guiding the side legs 16 of the core 12, and its inner peripheral surface has an outer coil. 30 is located.

Mounting edges 64 , 64 are integrally formed at both ends of the cover body 62 in the Z-axis direction. The Z-axis upper mounting edge 64 is engaged with the upper surface of the bobbin upper collar portion 48 , the Z-axis lower mounting edge 64 is engaged with the lower surface of the bobbin substrate 42 , and the core cover 60 is attached to 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 thereof in the X-axis direction. Engagement convex portions 66a projecting 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 engagement protrusion 66a on the upper side of the Z-axis engages with the inner surface of the insulating wall 49d of the lead drawing portion 49, and the engagement protrusion 66a on the lower side of the Z-axis extends from both ends of the bobbin substrate 42 on the X-axis to the lower side of the Z-axis. engages the inner surface of leg 42a integrally molded toward .

As a result, as shown in FIG. 1, the insulating plate portion 66 of the core cover 60 is combined with the insulating wall 49d and the leg portion 42 to improve insulation between the core 12 and the outer coil 30. As shown in FIG. The inner surface of the insulating plate portion 66 may be in contact with the core 12 or may have a shape matching the outer shape of the core 12 .

On the outer peripheral surface of the second hollow cylindrical portion 54 of one half 50a constituting the wire cover 50 shown in FIG. 54a is formed so as to protrude outward in the X-axis direction. The deflection convex portion 54a is formed integrally with the half-split body 50a by injection molding or the like. As shown in FIG. 1, one lead portion 32a of the second wire 32 that constitutes the outer coil 30 can be engaged with the deflecting convex portion 54a on the lower side in the Z-axis direction, and , and guided to the common lead-out groove 49 a of the lead lead-out portion 49 .

As shown in FIG. 5, the inner peripheral surface of the second hollow cylindrical portion 54 of the other half 50b constituting the wire cover 50 shown in FIG. are formed along the Z-axis direction. A positioning recess 51 is formed in the bottom wall of the passage recess 56 . As shown in FIGS. 6A and 6B, the lead portion 22a of the first wire 22 drawn out from the lower side of the Z-axis is guided in the upper Z-axis direction in the recessed portion 56 for passage. As shown in FIG. 6B , the positioning protrusions 47 c are fitted into the positioning recesses 51 to position the wire cover 50 and the bobbin 40 .

The inner peripheral surface of the second hollow cylindrical portion 54 of one of the half bodies 50a constituting the wire cover 50 shown in FIG. (not shown) are formed so that they can be fitted into the positioning projections 47b shown in FIG. 2B. Unlike the half-split body 50b shown in FIG. 5, the passage concave portion 56 is not formed on the inner peripheral surface of the second hollow cylindrical portion 54 of the half-split body 50a.

As shown in FIGS. 3A to 3C, in the present embodiment, winding sections 47 are formed at predetermined intervals along the Z-axis direction on the outer peripheral portion of the first hollow cylindrical portion 44 having a substantially elliptical cylindrical shape. , an elliptical ring-shaped wound partition brim 46 is formed on a plane substantially parallel to the XY axis. In this embodiment, seven winding partition ribs 46 are formed substantially parallel at predetermined intervals along the Z-axis direction, but the number is not particularly limited. The region where these winding partition ribs 46 are formed becomes the first winding portion 45 .

In this embodiment, a non-wound section 47a, shown in FIG. 4A, in which the first wire 22 shown in FIG. A winding restricting collar 43 is formed for this purpose. That is, in the present embodiment, the first winding portion is formed between the bobbin upper collar portion 48 and the winding restricting collar 43 on the outer peripheral portion of the first hollow cylindrical portion 44, and a plurality of winding partition walls are formed in that portion. Collars 46 are formed at predetermined intervals along the Z-axis direction.

The winding section width along the winding axis (Z-axis) in each winding section 47 separated by the winding partition collar 46 is set to a width that allows only one wire 22 to enter. That is, the winding section width w1 (see FIG. 3B) is preferably d1<w1<(2×d1), more preferably d1<w1<(1.2×d1) with respect to the wire diameter d1 of the wire 22. ) is preferred. If the winding section width w1 is too wide with respect to the wire diameter d1, winding disorder is likely to occur, and it goes against the demand for a compact coil device.

In addition, in each winding section 47, the winding section width is preferably the same, but may be slightly different. Also, the winding section width between the bobbin upper collar 48 and the uppermost winding partition collar 46 may be greater than the winding section width between the winding partition collars 46 . Similarly, even if the winding section width between the winding restricting collar 43 and the winding partition wall collar 46 positioned at the lowest position is larger than the winding section width between the winding partition wall collars 46 . good.

The height h1 of each winding partition brim 46 is preferably larger than m×d1, where m is the total number of windings to be wound on each winding section 47. . In that case, the top portion of the winding partition flange 46 is brought into contact with the inner peripheral surface of the wire cover 50 shown in FIG. can be positioned. In the present embodiment, the total number of turns m to be wound around each winding section 47 is 2, but may be 3 or more.

It is not necessary to bring the tops of all the winding partition ribs 46 into contact with the inner peripheral surface of the wire cover 50, and any one, preferably two or more winding partition collars spaced apart in the winding axial direction The length may be set longer than the other winding partition rib collars, and only the top portions of those winding partition rib collars may be positioned so as to abut on the inner peripheral surface of the wire cover 50 . Alternatively, the outer periphery of the winding restricting collar 43 may be brought into contact with the inner peripheral surface of the wire cover 50 .

Note that the height h1 of the winding partition brim 46 may be smaller than m×d1. However, the length Δh (=m×d1−h1) of the protruding portion is preferably smaller than d1/2 so that the wire 22 does not move to the adjacent winding section 47 . Also, the protruding height of the bobbin base plate 42 and the bobbin upper flange 48 is preferably higher than the protruding height of the winding partition wall flange 46 .

The first wire 22 may be composed of a single wire, or may be composed of a stranded wire, and is preferably composed of an insulated wire. The outer diameter d1 of the first wire 22 is not particularly limited, but is preferably φ1.0 to φ3.0 mm, for example, when a large current is applied. The second wire 32 may be the same as the first wire 22, but may be different.

In this embodiment, the inner coil 20 of the first wire 22 shown in FIG. 2B constitutes the primary coil of the transformer and the outer coil 30 of the second wire 32 wound around the wire cover 50 is the secondary coil. Configure the coil. Therefore, in this embodiment, as shown in FIG. 6B, the second wire 32 forming the outer coil 30 has a larger wire diameter than the first wire 22. However, the wire diameter is There is no particular limitation, and the wire diameters may be the same or may be different. Also, the materials of the first wire 22 and the second wire 32 may be the same or different.

As shown in FIGS. 3A and 3B, in the bobbin 40 of this embodiment, each winding partition collar 46 is formed with at least one communication groove 46a for connecting adjacent winding sections 47 to each other. In this embodiment, the circumferential position of at least one of the pair of cutout edges 46b and 46c formed in the winding partition brim 46 so as to define the circumferential width w2 of each communication groove 46a is Z It is different between adjacent winding partition rib collars 46 along the axial direction (winding axis). Note that the circumferential direction is the direction along the elliptical outer peripheral surface of the hollow cylindrical portion 44 .

In this embodiment, the circumferential widths w2 of the connecting grooves 46a adjacent to each other along the Z-axis direction are different from each other, and the circumferential widths w2 of the connecting grooves 46a extend from the center outward along the Z-axis direction. Width w2 is increased. Furthermore, the circumferential position of the cutout edge 46b on one side of the pair of cutout edges 46b and 46c formed in each of the winding partition ribs is oriented upward from the center along the Z-axis direction. It is in a position to spread out. The circumferential position of the notch edge 46c on the other side is at the same position upward from the center along the Z-axis direction.

In addition, the circumferential position of the cutout edge 46c on the other side of the pair of cutout edges 46b and 46c formed in each winding partition brim 46a is downward from the center along the Z-axis direction. It is in a position to spread out. The circumferential position of the notch edge portion 46b on one side is the same downward from the center along the Z-axis direction. The notch angle of the notch edges 46b and 46c with respect to the outer peripheral surface of the hollow cylindrical portion 44 is not particularly limited, but as shown in FIG. Only the edges 46b and 46c may be angled nearly parallel to the X-axis, and the other notched edges 46b and 46c may be angled nearly to the Y-axis.

As shown in FIGS. 3A and 3B, in the bobbin 40 of the present embodiment, the first wire 22 is α-wound, for example, from the central portion of the first winding portion 45 in the Z-axis direction. That is, the central portion 22c of the first wire 22 is arranged so as to pass through the communication groove 46a located in the central portion of the first winding portion 45 in the Z-axis direction, and the first wire 22 is directed from the central portion to the end. One of the lower winding portions 22d is passed through the winding section 47 one step below the center. In addition, the other upper winding portion 22d of the first wire 22 is passed from the central portion toward the end through the winding section 47 positioned one above the winding section 47 through which the lower winding portion 22d is passed.

After that, the lower winding portion 22d is wound twice in the same winding section 47 to the left as viewed from the Z-axis, and the upper winding portion 22e is wound in the same winding section 47 on the upper stage from the Z-axis. As you can see, make two turns with a right turn. After that, the lower winding portion 22d moves from the winding section 47, which has been wound twice, through the connecting groove 46a to the winding section 47 one step lower in the Z-axis direction, and in the winding section 47, it is also wound in the same direction. is wound on. In addition, the upper winding portion 22e moves from the winding section 47 in which two windings are made to the winding section 47 one step higher in the Z-axis direction through the communication groove 46a, and in the winding section 47, in the same direction. be wound.

By repeating the operation, the first wire is α-wound around the first winding portion 45 . 4A and 4B show the state of the bobbin 40 around which the first wire 22 is wound after α-winding. As shown in FIG. 4A , the lead portion 22 a from the lower winding portion 22 d of the first wire 22 after α-winding is engaged with the deflecting convex portion 46 d and lifted upward in the Z-axis direction, and the lead portion 49 is pulled out. are led to the common lead-out groove 49a. Further, the lead portion 22a from the upper winding portion 22e of the first wire 22 after α winding is directly guided to the common lead-out groove 49a of the lead lead-out portion 49, passes through the individual lead-out groove 49b, and is different from the other lead portions 22a. pulled out in the direction

On the other hand, as shown in FIGS. 2A and 2B, in the wire cover 50, the second wire 32 that constitutes the outer coil 30, which is the secondary coil, is wound in alignment on the second wound portion 55 thereof. Aligned winding is a winding method in which the wire 32 is sequentially wound from one end to the other end in the Z-axis direction around the outer peripheral surface of the winding portion 55. In this embodiment, only one layer is aligned. It's wrapped. If two layers are wound in an aligned manner, the first layer is entirely wound, and then the second layer is wound thereon.

The coil device 10 according to this embodiment is manufactured by assembling each member shown in FIG. 2A and winding a wire around the bobbin 40 and the wire cover 50 . This coil device 10 may be housed inside a case. Further, the inside of the case may be filled with heat-dissipating resin. Although the resin for heat dissipation is not particularly limited, for example, a resin having a heat conductivity of 0.5 to 5, preferably 1 to 3 W/m·K and having excellent heat dissipation properties is preferable.

Examples of resins having excellent heat dissipation properties include silicone-based resins, urethane-based resins, and epoxy-based resins. Among them, silicone resins and urethane resins are preferred. Moreover, in order to improve heat dissipation, the resin may be filled with a filler having high thermal conductivity.

The heat-dissipating resin of the present embodiment preferably has a Shore A hardness of 100 or less, preferably 60 or less. This is because, even if the core 12 is deformed by heat, the deformation is absorbed and the core 12 is prevented from being subjected to excessive stress. A potting resin is exemplified as such a resin.

A cooling device such as a cooling pipe, cooling fins, or the like may be mounted directly below the case via a metal plate or the like.

An example of a method for manufacturing the coil device 10 will be described below with reference to FIGS. 2A and 2B. In manufacturing the coil device 10, first, the bobbin 40 is prepared. Although the material of the bobbin 40 is not particularly limited, the bobbin 40 is made of an insulating material such as resin.

Next, the first wire 22 is wound around the outer periphery of the first hollow cylindrical portion 44 of the bobbin 40 to form the inner coil 20 . Although the first wire 22 used to form the inner coil 20 is not particularly limited, a litz wire or the like is preferably used.

Next, the wire cover 50 is attached to the bobbin 40 on which the inner coil 20 is formed. A second wire 32 forming the outer coil 30 is wound around the outer circumference of the second hollow cylindrical portion 54 of the wire cover 50 .

After that, the core covers 60 are attached to both sides of the wire cover 50 in the Y-axis direction, and then the core 12 is attached from above and below in the Z-axis direction. That is, the tips of the middle legs 14 and 14 of the core 12 and the tips of the side legs 16 and 16 are butted against each other. A gap may be provided between the tips of the middle legs 14 , 14 .

The material of each core 12 includes, but is not particularly limited to, soft magnetic materials such as metal and ferrite. The core 12 is fixed to the wire cover 50 and the bobbin 40 by bonding with an adhesive or by winding the outer circumference with a tape-like member.

In this embodiment, the coil device 10 may be impregnated with varnish after a series of assembly steps. The coil device 10 according to the present embodiment can be manufactured through the steps described above.

After that, the coil device 10 may be housed inside a case filled with heat-radiating resin. The resin may be filled before or after the coil device 10 is housed inside the case.

Further, since the coil device 10 of the present embodiment can be used as a vertical type coil device in which the winding axis of the coil is arranged perpendicular to the surface of the mounting board, the core inserted into the hollow portion of the bobbin 40 12 is easy to cool.

Furthermore, in this embodiment, as shown in FIG. 2, the wire cover 50 can be split at the split connection portion 53 parallel to the winding axis, so that the wire cover 50 can be easily arranged around the bobbin 40. can be done.

In the coil device 10 of the present embodiment, in order to wind the wire 22 so that only a single wire winding portion exists along the winding axis direction in each winding section 47, the wire 22 per layer is wound. It becomes easy to prevent variations in the number of turns, contributing to stabilization of leakage characteristics. That is, it becomes easy to strictly control the coupling coefficient between the outer coil 30 forming the secondary coil and the inner coil 20 forming the primary coil. be able to.

In the present embodiment, as shown in FIG. 6B, the first total width of the first winding portion 45 in the winding axial direction of the inner coil 20 and the second winding portion 55 of the outer coil 30 in the winding axial direction It is different from the second full width. Moreover, it is defined that the second wire 32 is wound in a predetermined length range along the winding axis on the outer peripheral portion of the wire cover 50, including the position corresponding to the non-winding section 47a. Locating collars 52, 58 are formed. By configuring in this way, it is possible to position the winding portion of the second wire 32 outside the non-winding section 47a where the first wire 22 is not wound. 10 leakage characteristics can be adjusted easily and accurately.

As shown in FIG. 3B, in the bobbin 40 according to the present embodiment, at least one of the pair of cutout edges 46b and 46c formed in the winding partition brim 46 so as to define the circumferential width of the communication groove 46a. One circumferential position is different between the adjacent winding partition rib collars 46 along the Z-axis direction. Therefore, even if the first wire 22 is wound in two or more layers around each winding section 47, as shown in FIG. 22b can be shifted along the circumferential direction.

That is, in the bobbin 40 of the present embodiment, even if the wire is wound in two or more layers on each winding section 47, swelling and winding disturbance due to the crossing portion 22b of the wire 22 near the communication groove 46a are eliminated, and the coil characteristic value variation is also small. Also, the coil device 10 can be easily miniaturized.

Further, in the present embodiment, the circumferential widths of the connecting grooves 46a adjacent to each other along the Z-axis direction are different from each other. Furthermore, the circumferential width of the communication groove 46a increases from the center toward the outside along the Z-axis direction. Furthermore, one of the pair of notch edges 46b and 46c formed in each winding partition rib 46 is positioned such that one circumferential position widens upward from the center along the Z-axis direction. It is in. moreover,
The circumferential position of the other side of the pair of notch edges 46b and 46c formed in each winding partition flange 46 is located at a position that widens downward from the center along the Z-axis direction.

With this configuration, particularly when the wire is α-wound from the central portion of the bobbin 40 in the winding axis direction, the crossing portion of the wire is shifted in the circumferential direction along the winding axis direction in the communication groove 46a. easier.

Further, in this embodiment, as shown in FIGS. 6A and 6B, the inner peripheral portion of the wire cover 50 is formed with a passage concave portion 56 for pulling out the lead portion 22a of the first wire 22 upward in the winding axis direction. Therefore, the size of the coil device 10 can be reduced.

In addition, in this embodiment, the outer peripheral edge of the winding partition brim 46 can contact the inner peripheral portion of the wire cover 50 at portions other than the positions of the passage recess 56 and the communication groove 46a. By configuring in this way, the distance between the coils 20 and 30 of the wire wound inside and outside the wire cover 50 can be easily made constant, and variations in coil characteristic values can be reduced.

Further, in the present embodiment, the outer periphery of the wire cover 50 is provided with a deflecting convex portion for hooking the lead portion 32a of the second wire 2 wound around the lower end portion in the Z-axis direction and directing it upward in the Z-axis direction. 54a is formed. Therefore, it becomes easier to form the lead drawing portion 49 or the terminal block on the upper portion of the bobbin 40 in the direction of the winding shaft.

The coil device 10 of the present embodiment is particularly effective when the first wire 22 is wound in two or more layers around the winding section 47 . Moreover, it is particularly effective when the width of the winding section 47 in the winding axis direction is set to a width that allows the single first wire 22 to enter, and it is possible to effectively prevent winding disorder.

In this embodiment, the first wire 22 arranged on the inner peripheral side is the primary coil of the transformer, but conversely, it may be the secondary coil (inner coil 20) to which a higher voltage acts. . In this case, the secondary coil (inner coil 20) to which a high voltage acts is arranged inside the primary coil (outer coil 30) to which a relatively low voltage acts, thereby facilitating insulation.

Second Embodiment As shown in FIGS. 3E and 4C, a bobbin 40a according to a second embodiment of the present invention differs from the bobbin 40 according to the first embodiment only in the following points. are the same, and different parts will be described below.

In the bobbin 40a of this embodiment, the circumferential width of the communication groove 46a is substantially the same along the Z-axis, which is the direction of the winding axis. However, the communication groove 46a is obliquely formed in the outer peripheral portion of the bobbin 40. As shown in FIG. That is, as shown in FIG. 3E, the circumferential position of the notch edge 46b on one side of the pair of notch edges 46b and 46c is displaced stepwise from top to bottom along the Z-axis direction. is in a position to Similarly, the circumferential position of the cutout edge 46c on the other side of the pair of cutout edges 46b and 46c is also at a position that is displaced stepwise from top to bottom along the Z-axis direction.

With this configuration, as shown in FIG. 4C, the circumferential positions of the crossing portions 22b of the wires 22 passing through the connecting grooves 46a adjacent in the Z-axis direction can be shifted in the circumferential direction. be possible.

That is, in the bobbin 40a of the present embodiment, even if the wire is wound in two or more layers on each winding section 47, the bulge and winding disturbance due to the crossing portion 22b of the wire 22 near the communication groove 46a are eliminated, and the coil characteristic value variation is also small. Also, the size of the coil device can be easily reduced.

In the conventional bobbin, as shown in FIG. 4D, the notch edges 46b and 46c of the winding partition flange 46 defining the communication groove 46a are formed linearly along the Z axis. . For this reason, as shown in FIG. 4D , there is a problem that the intersecting portion 22b of the wire 22 is overlapped in the winding axis direction at the portion of the communication groove 46a, and the collar portion 46 is deformed.

It should be noted that 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, the first wire 22 does not have to be α-wound, and may be line-wound. The effects of the present invention can be expected even with regular winding. Furthermore, the specific shape of the bobbins 40, 40a or the specific shape of the core 12 is not limited to the above-described embodiment, and can be variously modified.

DESCRIPTION OF SYMBOLS 10... Coil device 12... Core 13... Base 14... Middle leg 16... Side leg 20... Inner coil 22... First wire 22a... Lead part 22b... Intersection part 22c... Central part 22d... Lower winding part 22e... Upper winding part 30 Outer coil 32 Second wire 32a Leads 40, 40a, 40b Bobbin 42 Bobbin substrate 42a Leg 43 Winding restricting collar 44 First hollow cylinder 44a First through hole 44b For separation Convex part 45... First winding part 46... Winding partition flange 46a... Communication groove 46b, 46c... Notch edge part 46d... Deflection convex part 47... Winding section 47a... Non-winding section 47b, 47c... Positioning convex part 48 --- Bobbin upper collar 49 -- Lead drawer 49a -- Common drawer groove 49b -- Individual drawer groove 49c -- Base 49d -- Insulating wall 50 -- Wire cover 50a, 50b -- Half-split body 51 -- Positioning recess 52 -- Wire cover lower collar 53... Division connection part 54... Second hollow cylindrical part 54a... Deflection convex part 55... Second winding part 56... Passage recess 58... Wire cover upper flange 60... Core cover 62... Cover main body 64... Mounting edge 66 …Insulating plate

Claims (13)

a bobbin having an outer periphery around which the wire is wound;
a first wire wound around the outer periphery of the bobbin;
a wire cover that surrounds the bobbin around which the first wire is wound;
a second wire wound around the outer periphery of the wire cover;
The bobbin is
A plurality of winding partition ribs are formed on the outer peripheral portion for separating the wire winding portions adjacent to each other along the winding axis of the wire for each winding section,
At least one connecting groove is formed in each of the winding partition ribs for connecting adjacent winding sections,
Circumferential position of at least one of a pair of cut-out edges formed in the plurality of winding partition flanges so as to define the circumferential width of each of the communication grooves formed in the plurality of winding partition flanges is different between adjacent winding partition collars along the direction of the winding axis ,
A coil device according to claim 1, wherein an inner peripheral portion of the wire cover is formed with a passage concave portion for pulling out the lead portion of the first wire upward in the direction of the winding axis . 2. The coil device according to claim 1, wherein circumferential widths of said communication grooves adjacent to each other along the direction of said winding axis are different from each other. 3. The coil device according to claim 2, wherein the circumferential width of the communication groove increases from the center toward the outside along the direction of the winding axis . The circumferential position of one of the pair of cutout edges formed in each of the winding partition ribs extends upward from the center along the direction of the winding axis and extends from the communication groove. at a position where the circumferential width widens,
The circumferential position of the other side of the pair of cutout edges formed on each of the winding partition ribs is positioned downward from the center along the direction of the winding axis in the communication groove. 4. The coil device according to claim 3, wherein the circumferential width is widened. 2. The coil device according to claim 1, wherein the circumferential width of said communication groove is substantially the same along the direction of said winding axis . Each of the plurality of winding partition rib flanges The communication groove is the outer peripheral portion of the bobbinA position shifted stepwise from top to bottom along the direction of the winding axisof claim 5 formed inCoil device. 2. A winding restricting collar for forming a non-winding section in which the first wire is not wound is formed at the upper end or the lower end of the outer peripheral portion of the bobbin in the direction of the winding axis. 7. The coil device according to any one of -6. 8. The coil device according to claim 7 , wherein a positioning portion for positioning and attaching the wire cover to the bobbin is formed on the outer peripheral portion of the bobbin located in the non-winding section. Positioning for restricting the second wire from being wound within a predetermined length range along the winding axis, including positions corresponding to the non-winding sections, on the outer peripheral portion of the wire cover. 9. A coil device according to claim 7 or 8 , wherein a flange is formed. 2. The coil device according to claim 1 , wherein the outer peripheral edge of the winding partition brim can come into contact with the inner peripheral portion of the wire cover at portions other than the positions of the passage recess and the communication groove. On the outer periphery of the wire cover, there is a deflecting convex portion for hooking the lead portion of the second wire wound around the lower end portion in the direction of the winding axis and directing it upward in the direction of the winding axis. The coil device according to any one of claims 1 to 10 , wherein the coil device is formed. The coil device according to any one of claims 1 to 11 , wherein the first wire is wound in two or more layers on the winding section. The coil device according to any one of claims 1 to 12 , wherein the width of the winding section in the direction of the winding axis is set so that the single first wire can enter.

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