JP2001085245A - Wound coil and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wound coil which has a less variation in distributed capacitance in a winding and is excellent in frequency characteristic, and its manufacturing method. SOLUTION: A winding 13 is wound around the winding part 12 of a bobbin 11, and a magnetic core 14 is inserted into the winding part 12, forming a closed magnetic circuit interlinked with the winding 13 by using the magnetic core 14. Each flange 11a is arranged so that an outer periphery 18 on the side of the magnetic core 14 may be projected over the surface of the winding 13. A gap g1 is formed between the flange 11a and magnetic core 14. The gap g1 is set dimensionally so that a liquid varnish 17 may be sucked into its inside through capillary phenomenon. Therefore, the gap g1 is dipped in the varnish 17 and it is solidified, and then the bobbin 11 and magnetic core 14 are fixed with the varnish 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a wound coil and a method of manufacturing the same, and more particularly, to a wound coil used as a common mode choke coil or a hybrid choke coil and a method of manufacturing the same.

[0002]

2. Description of the Related Art As this kind of wound type coil, the one shown in FIG. 8 is generally known. The coil 3
0 denotes windings 33, 33 on a cylindrical winding portion 32 of the bobbin 31.
Is wound. Leg portions 34a, 34a of magnetic material cores 34, 34 having a substantially U shape are inserted through the winding portion 32 of the bobbin 31. The magnetic cores 34, 34 are joined to form a closed magnetic path that links the windings 33, 33. Bobbin 3
1 has flange portions 31 at both ends and an intermediate portion of the winding portion 32.
a, 31a and 31b. Collar 3
Terminal blocks 35, 35 are formed on 1a, 31a, respectively, and these terminal blocks 35, 35 are provided with terminal pins 36,..., 36 to which the ends of the windings 33, 33 are soldered. .

The bobbin 31 and the magnetic cores 34, 34
Conventionally, they have been fixed to each other by a varnish. That is, the bobbin 31 with the magnetic cores 34, 34 mounted in a bath filled with the liquid varnish 37 with the terminal blocks 35, 35 facing upward, and the axis of the winding portion 32 with respect to the varnish surface. Immersion is performed substantially parallel to the bobbin 31 and the magnetic cores 34, 34.
And a varnish 37 is impregnated. After this, bobbin 31
The bobbin 31 and the magnetic core 34,
And are fixed to each other by bonding with a varnish 37.

The bobbin 31 and the magnetic cores 34, 34
Another method for fixing the adhesive is to apply an adhesive using a dispenser. In this method, the flanges 31a and 31a of the bobbin 31 are
4, 34, etc., an adhesive is applied to a predetermined location, and the bobbin 31 and the magnetic core 3
4 and 34 are fixed to each other.

[0005]

By the way, in the method in which the bobbin 31 and the magnetic cores 34, 34 are adhered and fixed to each other by varnish impregnation, the magnetic cores 34, 34 are placed in a tank filled with a varnish 37. The bobbin 31 on which the bobbin 31 is mounted is dipped and pulled up, and the adhering varnish 37 may be dried, so that the bobbin 31 and the magnetic cores 34, 34 can be easily bonded with a small number of steps. I have. However, in this method, when the bobbin 31 is immersed in the varnish 37, the varnish 37 adheres to the windings 33, 33. Varnish 3
7 has a much higher dielectric constant than air,
When the varnish 37 adheres to the portions 3, 33, there is a problem that the distribution capacity of that portion increases and the frequency characteristics of the coil 30 deteriorate.

In the method of applying an adhesive using a dispenser, the adhesive does not adhere to the windings 33, 33, so that a change in the distributed capacitance can be avoided. But,
The dispenser must apply an adhesive to a plurality of necessary locations, such as between the magnetic cores 34, 34 and between the magnetic core 34 and the bobbin flange 31a. It is necessary to use a plurality of adhesives suitable for the material of the bobbin 31 and the magnetic cores 34 and 3.
There has been a problem that the number of steps for bonding with the No. 4 increases and the manufacturing cost increases. Also, when the applied adhesive is solidified, the part becomes a hemispherical shape or the like, and swells,
There is also a problem that it is disadvantageous for automatic mounting on a printed circuit board or the like. It should be noted that the adhesive solidifies and the magnetic material core 34
, There is a problem that the magnetic permeability of the magnetic core 34 decreases and the inductance value of the coil 30 deteriorates.

An object of the present invention is to provide a winding type coil having a small variation in the distributed capacitance of the winding and excellent frequency characteristics, and a method of manufacturing the same.

[0008]

In order to achieve the above-mentioned object, a wire-wound coil according to the present invention includes a tubular winding portion and a flange provided at an end of the winding portion. A winding is wound around a cylindrical winding portion of a bobbin, and a magnetic core is inserted through the winding portion, and the bobbin and the magnetic core are fixed with an adhesive. The flange portion has an outer peripheral edge on the side where the magnetic core is disposed protruding from a position on the surface of the winding, and a gap dimension formed between a side surface of the flange portion and the magnetic core is: The dimension is such that the liquid adhesive is sucked up by capillary action.

With the above arrangement, when the outer peripheral edge of the flange protruding from the position of the surface of the winding is immersed in a liquid adhesive solution, the gap in the gap formed between the side surface of the flange and the magnetic core is reduced. Then, the adhesive is sucked up by capillary action. At this time, since the winding wound around the bobbin is located above the liquid surface of the adhesive solution, the adhesive does not adhere to the winding.

In the method of manufacturing a wound coil according to the present invention, the flange is immersed in a liquid adhesive solution with the axis of the bobbin inclined, and the gap between the side surface of the flange and the magnetic core is formed. The adhesive is sucked up in the gap formed by the capillary action.

According to the above-described method, while the winding wound on the bobbin is held on the liquid surface of the adhesive solution, the adhesive is inserted into the gap formed between the side surface of the flange portion and the magnetic core. Can be sucked up by capillary action.

Further, in the method of manufacturing a wound coil according to the present invention, the flange is immersed in a liquid adhesive solution while the magnetic core is brought close to the side surface of the flange by the jig. The adhesive is sucked up by a capillary phenomenon into a gap formed between the side surface of the magnetic core and the magnetic material core.

According to the above method, the gap formed between the side surface of the flange portion and the magnetic core is set to a size suitable for the capillary phenomenon, so that the adhesive can be reliably sucked into the gap.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a winding type coil and a method of manufacturing the same according to the present invention.

[First Embodiment, FIGS. 1 to 5] FIGS. 1 and 2 show the configuration of an embodiment of a wound coil according to the present invention and an electric equivalent circuit diagram thereof. The coil 1
Numeral 0 is used as a choke coil, and windings 13, 13 are attached to a cylindrical winding portion 12 (see FIG. 3) of the bobbin 11.
13 are wound. The winding portion 12 has legs 14c on one side of a pair of magnetic cores 14 having a substantially U shape.
14c is inserted. The magnetic cores 14 and 14 are joined to form a closed magnetic path linking the windings 13 and 13. In this case, in order to securely join the two magnetic cores 14, 14, the two magnetic cores 14, 14 are sandwiched by a spring member or the like as appropriate. The bobbin 11 has flange portions 11a, 11a at both ends and an intermediate portion of the winding portion 12.
And 11b are formed, and flange portions 11a, 1 at both ends are formed.
Terminal blocks 15 and 15 are formed in 1a, respectively.
The terminal blocks 15, 15 are provided with terminal pins 16,..., 16 to which the ends of the windings 13, 13 are soldered.

Each of the flanges 11a, 11a is set such that the outer peripheral edges 18, 18 on the side where the magnetic cores 14, 14 are disposed protrude from the positions of the surfaces of the windings 13, 13. In other words, as shown in FIG.
The distance d between the winding 13 and the axis of the winding portion 12 is the radius r of the winding 13.
It is set to be larger than. Preferably,
The dimension d-r may be set to a minimum dimension at which the winding 13 is not immersed in the liquid varnish 17 and the outer peripheral edge 18 is immersed.

In each of the side surfaces of the flanges 11a, 11a, a guide groove 1 extending from the hole of the winding portion 12 to the outer peripheral edge 18 is provided.
9 and 19 are provided to position the magnetic cores 14 and 14. Then, the connecting portion 14 between the bottom wall surface of the guide groove 19 and the two legs 14a and 14c of the magnetic core 14 is formed.
b, a gap g1 (see FIG. 3) is formed, and a gap g2 (see FIG. 4) is formed between the side wall surface of the guide groove 19 and the coupling portion 14b. These gaps g
Each of 1 and g2 is set to a size in which the liquid varnish 17 is sucked up by capillary action. Each of the gaps g1 and g2 is impregnated with a liquid varnish 17 and solidified as described below, and the bobbin 11 and the magnetic cores 14 and 14 are bonded to each other by the varnish 17.

The bonding between the bobbin 11 and the magnetic cores 14, 14 by the varnish 17 can be performed as follows. As shown in FIGS. 3 and 4, the bobbin 11 having the magnetic cores 14 attached thereto in a bath filled with the liquid varnish 17 with the terminal blocks 15, 15 of the wound coil 10 facing upward, The winding part 12 is immersed with its axis substantially parallel to the varnish surface. At this time, the winding type coil 10 is
The windings 13, 13 are not immersed in the varnish 17, but are immersed up to the portion of the outer periphery 18, dr of 1 a, 11 a.
When the outer peripheral edges 18, 18 of the flange portions 11a, 11a are immersed in the varnish 17, the liquid varnish 1 is placed in the gaps g1, g2.
7 is sucked up by capillary action. In this case, the varnish 17 sucked up by the capillarity acts on the bobbin 11.
To the inside of the hole of the winding part 12. Thereafter, the wound coil 10 is pulled up, and the varnish 17 sucked up in the gaps g1 and g2 is dried and solidified, so that the bobbin 11 and the magnetic cores 14 and 14 are in contact with each other.
Are adhered to each other.

In the wound coil 10 of the first embodiment, since no varnish adheres to the windings 13, 13, a solid line h in FIG.
As shown by 1, it is possible to prevent the insertion loss characteristic from deteriorating due to the adhesion of the varnish 17 to the windings 13, 13. For comparison, FIG. 5 also shows the insertion loss characteristics of a conventional wound coil having a varnish attached to the winding (see dotted line h2). Further, according to the present embodiment, the bobbin 11 and the magnetic cores 14 can be bonded by the immersion method. Ten manufacturing steps are also significantly reduced.

[Second Embodiment, FIG. 6] FIG. 6 shows a second embodiment of the wound coil according to the present invention. The winding type coil 20 is provided with windings 23, 2 on a cylindrical winding portion 22 of a bobbin 21.
3 is wound. Each of the winding portions 22 has legs 24a, 2a on one side of a pair of magnetic cores 24, 24 having a substantially U shape.
4a is inserted. The magnetic cores 24, 24 are joined to form a closed magnetic path linking the windings 23, 23. The bobbin 21 has flange portions 21a, 21a, and 21b formed at both ends and an intermediate portion of the winding portion 22, and terminal blocks 25, 25 are formed at the flange portions 21a, 21a at both ends. These terminal blocks 25, 25 have windings 23,
There are provided terminal pins 26, 26 to which the ends of 23 are soldered.

In each of the flange portions 21a, the outer peripheral edges 28, 28 on the side where the magnetic cores 24, 24 are disposed are substantially equal to the positions of the surfaces of the windings 23, 23. In addition, collar 21
Guide grooves 29, 29 extending from the hole of the winding part 22 to the outer peripheral edge 28 are provided on the side surfaces of the magnetic cores 24 a, 21 a to position the magnetic cores 24, 24. Then, the bottom wall surface of the guide groove 29 and the two legs 24 of the magnetic core 24 are formed.
A gap g1 is formed between the coupling portions 24a and 24a, and a gap g2 (not shown) is formed between the side wall surface of the guide groove 29 and the coupling portion 24b. Each of these gaps g1 and g2 is set to a size in which the liquid varnish 17 is sucked up by capillary action. Each of the gaps g1 and g2 is impregnated with a liquid varnish 17 and solidified as described below, and the bobbin 21 and the magnetic cores 24 and 24 are bonded to each other by the varnish 17.

The bonding between the bobbin 21 and the magnetic cores 24, 24 by the varnish 17 can be performed as follows. With the terminal blocks 25, 25 of the coil 20 wound up,
The magnetic core 2 is placed in a tank filled with a liquid varnish 17.
And one end of the bobbin 21 with the attached
The second axis is immersed in an inclined manner with respect to the varnish surface. At this time, the wound coil 20 is connected to the outer peripheral edge 28 of the one flange 21a.
, And the windings 23, 23 are not immersed in the varnish 17. When the outer peripheral edge 28 of the flange portion 21a is immersed in the varnish 17, the liquid varnish 17 is sucked into the gaps g1 and g2 by capillary action. Thereafter, as in the first embodiment, the wound coil 20 is pulled up and then immersed up to the outer peripheral edge 28 of the other flange 21a of the wound coil 20,
The varnish 17 is sucked into the gaps g1 and g2. When the varnish 17 sucked into the gaps g1 and g2 is dried and solidified, the bobbin 21 and the magnetic core 2
4 and 24 are adhered to each other by the varnish 17.

In the wound coil 20 thus obtained, no varnish is attached to the windings 23, 23, so that the insertion loss in the high frequency region is suppressed. The method of manufacturing the wound coil 20 according to the second embodiment includes the bobbin 2
The varnish 17 can be sucked up into the gaps g1, g2 by capillary action without necessarily projecting the outer peripheral edges 28, 28 of the first flange portions 21a, 21a from the positions of the surfaces of the windings 23, 23. The size of the linear coil 20 can be reduced.

In the case of a wound coil in which a magnetic core is assembled to a bobbin, the dimensions of the gaps g1 and g2 may be set relatively large in consideration of manufacturing errors and the like. In this case, it is difficult for the gaps g1 and g2 to suck up the varnish 17 by utilizing the capillary phenomenon, and the fixing between the bobbin 21 and the magnetic cores 24 becomes uncertain.

Therefore, as shown in FIG. 7, the bobbin 21 and the magnetic core 24 are tightly attached to each other with a clip-shaped jig 40 having a substantially C-shaped spring force. The connecting portion 24b of the body core 24 is brought closer. In this state, one end of the bobbin 21 is immersed in a tank filled with the liquid varnish 17. Since the dimensions of the gaps g1 and g2 formed between the flange 21a and the magnetic core 24 are set to dimensions suitable for the capillary phenomenon by the jig 40, a liquid varnish is provided in the gaps g1 and g2. 17 is surely sucked up. Thus, the bobbin 21 and the magnetic core 24 are securely fixed. This manufacturing method can also be applied to the wound coil 10 of the first embodiment.

[Other Embodiments] The present invention is not limited to the above embodiment, and various configurations can be adopted within the scope of the present invention. In the first and second embodiments, a varnish as an adhesive is impregnated in all gaps formed between two flange portions provided at both ends of the winding portion of the bobbin and the magnetic core. Alternatively, the bobbin and the magnetic core may be fixed by impregnating only the gap formed between one of the flanges and the magnetic core with the varnish.

For example, in the wound coil 10 of the first embodiment described with reference to FIG.
When the gaps g1 and g2 formed between the flange 14a and the flanges 11a and 11a of the bobbin 11 have such dimensions that the liquid varnish 17 cannot be sucked up, the gaps g1 and g2 are close to the gaps g1 and g2. Although not specifically shown, for example, by disposing a clip-shaped jig, the gap between the jig and the magnetic cores 14 and the gap between the jig and the flanges 11a, 11a are reduced. The dimensions may be such that the varnish 17 can be sucked up using capillary action. By doing so, even if the gaps g1 and g2 are of such a size that the liquid varnish 17 and the like cannot be sucked up, the gaps g1 and g2 formed between the magnetic core 14 and the flange portion 11a are not formed. The varnish 17 can be sucked up by utilizing the capillary phenomenon.

[0028]

As is clear from the above description, according to the present invention, an adhesive having a large dielectric constant such as a varnish for bonding a bobbin and a magnetic core does not adhere to the winding. Therefore, it is possible to prevent the insertion loss characteristic from deteriorating due to the adhesion of the adhesive to the winding, and to obtain a winding type coil having excellent characteristics and little variation in characteristics.

Further, since the bobbin and the magnetic core can be bonded by the immersion method, the number of steps for bonding the bobbin and the magnetic core is small, and the number of steps for manufacturing the coil is greatly reduced. A wound coil can be obtained. The varnish is softer than the adhesive applied by the dispenser and has less stress applied to the solidified magnetic core, so that the deterioration of the inductance value of the coil can be suppressed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the configuration of a first embodiment of a wound coil according to the present invention.

FIG. 2 is an electric equivalent circuit diagram of the wire-wound coil shown in FIG.

FIG. 3 is a partial cross-sectional view for explaining a method of manufacturing the wire-wound coil shown in FIG.

FIG. 4 is a side view for explaining the method for manufacturing the wire-wound coil shown in FIG.

FIG. 5 is a graph showing insertion loss characteristics of the wound coil shown in FIG. 1;

FIG. 6 is a partial cross-sectional view showing a wire-wound coil and a method for manufacturing the same according to the present invention.

FIG. 7 is a partial cross-sectional view showing another method of manufacturing the wire-wound coil shown in FIG. 6;

FIG. 8 is a front view showing a conventional wound coil.

[Explanation of symbols]

 10, 20 ... wound type coil 11, 21 ... bobbin 11a, 11b, 21a, 21b ... flange part 12, 22 ... winding part 13, 23 ... winding 14, 24 ... magnetic core 17 ... varnish (adhesive) 18 ... Outer edge 40 ... Jig g1, g2 ... Gap

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Takaaki Oi 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto F-term in Murata Manufacturing Co., Ltd. (Reference) 5E043 AA02 AB01 FA01

Claims (3)

[Claims] A winding is wound around a cylindrical winding portion of a bobbin including a cylindrical winding portion and a flange provided at an end of the winding portion, and the winding is In a wound type coil in which a magnetic core is inserted into a portion and the bobbin and the magnetic core are fixed with an adhesive, the flange has an outer peripheral edge closer to the magnetic core disposed side than a position on the surface of the winding. A wire-wound coil which is protruding and has a gap dimension formed between a side surface of the flange portion and the magnetic core so that the liquid adhesive is sucked up by capillary action. 2. A winding is wound around a cylindrical winding portion of a bobbin having a flange portion, a magnetic core is inserted through the winding portion, and the bobbin and the magnetic core are bonded with an adhesive. In the method of manufacturing a wound coil to be fixed, the flange is dipped in a liquid adhesive solution while the axis of the bobbin is inclined, and formed between a side surface of the flange and the magnetic core. A method of manufacturing a wound-type coil, wherein an adhesive is sucked into a gap formed by capillary action. 3. A winding is wound around a cylindrical winding portion of a bobbin having a flange portion, a magnetic core is inserted through the winding portion, and the bobbin and the magnetic core are bonded with an adhesive. In the method of manufacturing a wound coil to be fixed, in a state in which the magnetic core is brought close to a side surface of the flange portion with a jig, the flange portion is immersed in a liquid adhesive solution, and the side surface of the flange portion is formed. A method of manufacturing a wound type coil, wherein an adhesive is sucked up by a capillary phenomenon into a gap formed between the coil and the magnetic core.