JP4317206B2 - Wire wound inductor - Google Patents

Description

  The present invention relates to a wire-wound inductor in which a lead wire is wound around a core so as to have inductance.

  A wire-wound inductor generally called a core coil is formed by winding a conductive wire around a core made of, for example, ferrite or a dielectric (in addition, an air-core coil is filled with a mixture of resin and iron powder. There are cores etc.).

  Since the conventional general winding type inductor has a configuration in which the conducting wire is wound around the outer peripheral surface of the cylindrical core having a constant outer diameter, for example, the winding diameter of the wound conducting wire is Therefore, each integrated winding inductor has only a single resonance frequency.

  Therefore, a wound inductor of a type having a constant outer diameter of the core can increase its impedance in its resonance frequency band and exhibit its function as an inductor (having a high attenuation), but its resonance frequency. Immediately outside the band, the impedance decreases and the function as an inductor is remarkably reduced (attenuation amount is remarkably reduced). Therefore, the inductor characteristics can be exhibited well only in a very narrow frequency band (a high attenuation amount is obtained). Is not possible).

  Therefore, in order to obtain a high attenuation in a wide frequency band, there is no choice but to connect a plurality of wound inductors having different resonance frequencies, which is costly and requires a large installation space. There were problems such as hindering downsizing.

  Therefore, as disclosed in Japanese Patent Application Laid-Open No. 2004-6695, a winding inductor having a configuration in which a conducting wire is wound around a conical or pyramidal core has been proposed.

  This is different from the above-mentioned type in which the outer diameter of the core is constant, as shown in FIG. 3, the outer diameter of the core is gradually reduced, and the winding diameter of the conductive wire wound around the core is also gradually increased. In order to reduce the diameter, it is a single winding type inductor but has a plurality of different resonance frequencies instead of a single one.

  Therefore, the wound inductor of the type in which the outer diameter of the core is changed is different from the above-described type in which the outer diameter of the core is constant, and the single wound inductor has a plurality of different resonance frequencies. Even though it is a wound inductor, it can function well as an inductor in a very wide frequency band, and a high attenuation can be obtained in a wide frequency band.

JP 2004-6695 A

  The present invention has been completed as a result of further research and development on the above-described wire wound inductor of the type in which the outer diameter of the core is changed. The inductor functions better in a wider frequency band than the conventional example. In addition, a single winding inductor can provide high attenuation in a wide frequency band, so it is excellent in cost and requires less installation space. For example, electronic products can be easily downsized. The present invention provides an extremely innovative wire-wound inductor with excellent practicality.

  The gist of the present invention will be described with reference to the accompanying drawings.

  A wire-wound inductor formed by winding a conductor 2 around a core 1, and the core 1 is configured such that the diameter of the conductor 2 wound around the core 1 is not constant but gradually decreases. The tapered portion 3 has a tapered portion 3 whose outer diameter gradually decreases, and the tapered portion 3 has a constant diameter reduction ratio from a large diameter proximal end to a small diameter distal end of the tapered portion 3. Tapering in which the reduction ratio of the outer diameter of the core 1 gradually decreases from the large base end of the taper-shaped portion 3 toward the tip of the small diameter without forming the taper shape in which the outer diameter of the core 1 is reduced. The present invention relates to a wound inductor characterized by being formed into a shape.

  The core 1 is a wire-wound inductor formed by winding a conducting wire 2 on the core 1, and the core 1 has a winding diameter of the conducting wire 2 wound around the core 1 that is not constant but gradually decreases. The core 1 has a tapered portion 3 whose outer diameter gradually decreases in diameter, and this tapered portion 3 has a constant diameter reduction ratio from the large proximal end to the small distal end of the tapered portion 3. Thus, the outer diameter of the core 1 is abruptly reduced on the large proximal end side of the tapered portion 3 without the taper shape in which the outer diameter of the core 1 is reduced. The present invention relates to a wound-type inductor characterized in that it is formed in a tapered shape that is gradually reduced in diameter as compared with a large base end side.

  Further, when the diameter reduction ratio of the outer diameter of the core 1 in the tapered portion 3 is R, the axial length of the core 1 is x, and the outer diameter is r, the diameter reduction ratio is R = −dr (x ) / Dx, wherein the tapered portion 3 is formed in a tapered shape in which the reduction ratio of the outer diameter of the core 1 in the tapered portion 3 is at least R ≧ 0. The winding inductor according to any one of claims 1 and 2.

  The core 1 has a straight portion 4 having a constant outer diameter, and is formed in a shape in which the outer diameter of the core 1 is reduced by the tapered portion 3 from an end portion of the straight portion 4. The winding inductor according to any one of claims 1 to 3, wherein:

  Since the present invention is configured as described above, the core is formed in a shape having a tapered portion in which the outer diameter of the core is not constant but gradually decreases, and the winding diameter of the conductive wire wound around the core is also the above-mentioned Since the diameter gradually decreases at the tapered portion, it has a plurality of different resonance frequencies instead of a single one, like a conventional wound inductor of a type in which the outer diameter of the core changes. Although it is a linear inductor, the function as an inductor can be satisfactorily performed in a wide frequency band by a plurality of resonance frequencies, and a high attenuation can be obtained in a wide frequency band.

  In addition, it is not necessary to connect a plurality of wound inductors having a single resonance frequency different from each other, and a high attenuation can be obtained in a wide frequency band with one product of the present invention. Therefore, it is not necessary to provide a large number of inductors, and it is possible to easily reduce the size of electronic products, for example, without hindering downsizing which is a concern in electronic products.

  In addition, in the present invention, the tapered portion of the core is not formed into a tapered shape in which the outer diameter of the core is reduced at a constant reduction rate from a conventional large diameter base end to a small diameter distal end. Tapered shape in which the diameter reduction rate of the outer diameter of the core gradually decreases from the large diameter proximal end of the tapered portion toward the small diameter distal end (that is, for example, the diameter is reduced at the large proximal end side of the tapered portion). The ratio is set high, and on the distal end side with a small diameter, the diameter reduction ratio is set lower than that on the proximal end side, and the outer diameter of the core is rapidly reduced on the proximal end side with a large diameter of the tapered portion. The shape is such that the diameter is reduced and the diameter gradually decreases on the tip side), so that a higher attenuation can be obtained in a wide frequency band. A configuration that obtains a high attenuation can be easily designed and realized.

  Further, according to the present invention, since the tapered portion has a shape capable of winding a wire having a larger number of windings than, for example, a columnar shape or a conical shape, the core has a larger number of times of winding. Of course, it can be wound, and the size of the core in the longitudinal direction may be set short to make it compact. For example, electronic products can be made more compact.

  Therefore, according to the present invention, a single winding inductor has a plurality of resonance frequencies, and a high attenuation can be obtained in such a wide frequency band. Since it can be made a wider range, it is possible to obtain a high attenuation in a wider frequency band than ever before, and it is also extremely revolutionary with excellent practicality, such as low cost and excellent compactness. It becomes a linear inductor.

  Embodiments of the present invention that are considered suitable (how to carry out the invention) will be briefly described with reference to the drawings, illustrating the operation of the present invention.

  The conducting wire 2 is wound around the core 1. At this time, the core 1 is not simply a shape having a constant outer diameter (for example, a cylindrical shape), but is formed into a shape having a tapered portion 3 whose outer diameter gradually decreases. The winding diameter of the wire 2 is not constant and gradually decreases in diameter at the tapered portion 3.

  Therefore, it has a plurality of different resonance frequencies due to a change (reduction in diameter) of the outer diameter of the core 1 and the winding diameter of the conductor 2.

  Therefore, for example, when the core 1 is simply cylindrical and the outer diameter is constant, as in the conventional example in which the outer diameter of the core 1 is constant, the winding diameter of the conductor 2 is also constant and only one resonance frequency. However, in the resonance frequency band, the function as an inductor can be satisfactorily achieved and a high attenuation can be obtained. However, if the resonance frequency band is deviated from the resonance frequency band, the function as an inductor is immediately reduced (attenuation). However, in the present invention, a single wound inductor has a plurality of resonance frequencies, and thus a high attenuation can be obtained in a wide frequency band. Function as an inductor).

  Moreover, in the present invention, the shape of the tapered portion 3 of the core 1 is a tapered shape (for example, a conical shape) whose outer diameter is reduced at a constant diameter reduction rate from a large diameter proximal end to a small diameter distal end. In other words, the taper portion 3 is formed in a tapered shape in which the diameter reduction rate of the outer diameter of the core 1 gradually decreases from the large diameter proximal end to the small diameter distal end. That is, the tapered portion 3 has the outer diameter of the core 1 abruptly reduced on the base end side having a large diameter, and the core 1 has a gentler diameter on the tip end side having a smaller diameter than the base end side having a large diameter. It has a tapered shape whose outer diameter is reduced.

  The diameter reduction ratio of the outer diameter of the core 1 in the tapered portion 3 is, for example, when the diameter reduction ratio is R, the axial length of the core 1 is x, and the outer diameter is r. Is represented by R = −dr (x) / dx, and the tapered portion 3 is tapered such that, for example, the reduction ratio of the outer diameter of the core 1 in the tapered portion 3 is at least R ≧ 0. (For example, as shown in FIG. 1, the hyperboloid shape in which the diameter reduction rate gradually decreases from the proximal end to the distal end, or for example, the inclination angle is different from the proximal end to the distal end as illustrated in FIG. An inclined surface having a plurality of inclined surfaces may be used.

  As described above, the core 1 not only has a shape having the tapered portion 3 in which the outer diameter of the core 1 gradually decreases, but the tapered portion 3 is formed on the proximal end side having a large diameter. The outer diameter of the core 1 is abruptly reduced, and the outer diameter of the core 1 is gradually reduced on the distal end side, which is smaller than that on the proximal end side. Compared with, for example, a tapered (conical) core 1 as illustrated in FIG. 3, a higher attenuation can be obtained in a wider frequency band, which is merely reduced at a constant reduction ratio from end to end. A wire wound inductor with excellent practicality.

  In particular, as in the invention described in claim 4, the core 1 has a straight portion 4 having a constant outer diameter, and the tapered portion 3 extends from the end of the straight portion 4 to the core 1. In the case where the outer diameter is formed in a reduced shape, the tapered portion 3 is formed in a tapered shape in which the reduction ratio of the outer diameter of the core 1 gradually decreases from the large-diameter base end toward the small-diameter tip. As a result, the amount of attenuation in the resonance frequency band of the straight portion 4 of the core 1 increases, and a high amount of attenuation can be obtained in such a wide frequency band.

  In addition, since the conductive wire 2 can be wound around the tapered portion 3 of the core 1 more times than simply in a columnar shape or a conical shape, for example, while the length of the core 1 is the same as the conventional one, Compared to the conventional configuration, the conductor 2 can be wound many times more times, or the length of the core 1 is set to be shorter than the conventional one while the number of windings of the conductor 2 is the same. In this respect, it is excellent in practicality.

  Specific embodiments of the present invention will be described with reference to the drawings.

  The present embodiment is a wound inductor formed by winding a conductor 2 around a core 1. The core 1 may be composed of ferrite or dielectric, and is generally used as this type of wound inductor, such as a structure in which an air-core coil is filled with a mixture of resin and iron powder. The configuration of the core 1 may be employed, and in the present embodiment, the one made of ferrite is employed. Further, a copper wire is adopted as the conducting wire 2.

  The core 1 has a shape having a tapered portion 3 in which the outer diameter of the core 1 is gradually reduced so that the winding diameter of the conducting wire 2 wound around the core 1 is not constant but gradually becomes smaller. is there.

  The tapered portion 3 formed on the core 1 has a tapered shape in which the outer diameter of the core 1 is reduced at a constant reduction ratio from the large-diameter base end to the small-diameter distal end of the tapered portion 3 (FIG. 3). 1), the taper-shaped portion 3 has a tapered shape in which the reduction ratio of the outer diameter of the core 1 gradually decreases from the large-diameter base end to the small-diameter tip as shown in FIG. Is formed.

  The reduction ratio of the outer diameter of the core 1 in the tapered portion 3 is defined as R, where the reduction ratio is R, the axial length of the core 1 is x, and the outer diameter is r. Is represented by R = −dr (x) / dx.

  The tapered portion 3 may be formed in a tapered shape in which the diameter reduction ratio of the outer diameter of the core 1 in the tapered portion 3 is at least R ≧ 0. In particular, in this embodiment, the tapered portion 3 is formed in a tapered shape in which the diameter reduction ratio is R> 0 from the large diameter proximal end to the small diameter distal end.

  Therefore, there is no portion where the outer diameter of the core 1 is constant or the portion where the outer diameter of the core 1 is increased from the large proximal end to the small distal end of the tapered portion 3, and this tapered portion 3 is not tapered. The tapered shape is such that the outer diameter of the core 1 is constantly reduced from the large diameter base end to the small diameter distal end of the shape portion 3.

Specifically, as shown in FIG. 1, the tapered portion 3 of the core 1 is abruptly reduced in diameter at the proximal end side of the tapered portion 3, and the diameter is reduced at the distal end side of the smaller diameter. in tapered shape gradually reduced in diameter compared to a large group end side, a hyperboloid shape radial contraction rate of the core 1 is gradually reduced toward the smaller diameter distal from large-diameter proximal end of the tapered portion 3 Is formed. The tapered section 3 has a circular cross-sectional view.

  Note that the shape of the tapered portion 3 is not limited to that of the present embodiment, but the actual outer diameter line is more than the virtual outer shape line connecting the large diameter base end and the small diameter distal end of the tapered portion. For example, as shown in FIG. 2, the tapered portion 3 of the core 1 has a large inclination angle on the base end side of the tapered portion 3 having a large diameter (as shown in FIG. 2). It may be formed in the shape of an inclined surface having a plurality of tapered surfaces having different inclination angles with a smaller inclination angle (smaller diameter reduction ratio) on the distal end side with a smaller diameter than that on the proximal end side. That is, as shown in FIG. 1, the diameter reduction ratio is not limited to a shape that gradually decreases gradually from the base end side with a large diameter toward the tip end side with a small diameter, but as in another example illustrated in FIG. In addition, a shape in which the diameter reduction rate gradually decreases stepwise may be used.

  Further, the core 1 is formed in a shape in which the conductors 2 adjacent to each other in the length direction (winding axis direction) of the core 1 wound around the core 1 are not separated from each other but are close to or in contact with each other. Yes. That is, if the outer shape of the core 1 is suddenly extremely reduced in diameter, that is, has a stepped portion, the conductor 2 wound on the upper side of the stepped portion and the conductor wound on the lower side. 2, thereby reducing the function as an inductor. Therefore, the conductors 2 adjacent to each other in the length direction of the core 1 have stepped portions having a difference in outer shape. The core 1 is formed in a shape that does not. The core 1 is formed in a shape having a stepped portion having a difference in outer diameter such that the conductors 2 adjacent to each other in the length direction of the core 1 are separated from each other, thereby reducing the attenuation amount in a specific frequency band. However, it may be configured as a so-called band-pass filter in which is significantly reduced.

  In the present embodiment, as shown in FIG. 1, the core 1 has a straight portion 4 having a constant outer diameter, and the tapered portion 3 extends from the end of the straight portion 4. The core 1 is formed in a shape in which the outer diameter is reduced.

  Specifically, the taper-shaped portion 3 formed on the core 1 has a shape having the straight-shaped portion 4 from a large base end (right side in FIG. 1). The straight portion 4 has a circular shape in a side sectional view, like the tapered portion 3.

  As shown in FIG. 1, the core 1 of the present embodiment has a configuration in which a hyperboloid tapered portion 3 is formed from one end of the straight portion 4. For example, the core 1 has a shape having a plurality of tapered portions 3. (In other words, for example, a shape in which the second tapered portion is formed from the small diameter tip of the first tapered portion 3). Further, the side sectional view shape of the core 1 may be a polygonal shape instead of a circular shape.

  Since the present embodiment is configured as described above, the outer diameter of the core 1 is reduced by the tapered portion 3 and the winding diameter of the conductor 2 wound around the core 1 is also reduced. It has a plurality of different resonance frequencies instead of the resonance frequency, and a high attenuation can be obtained in such a wide frequency band.

In addition, as shown in FIG. 1, the core 1 of this embodiment has the outer diameter of the core 1 abruptly reduced on the large base end side of the tapered portion 3, and the distal end side having a small diameter. in order to have a moderately reduced in diameter to tapered, high attenuation amount is obtained frequency band the core 1 is Ru more wide kuna. That is, as shown in FIG. 1, the tapered portion 3 has a hyperboloid tapered shape in which the reduction ratio of the outer diameter of the core 1 gradually decreases, so that the straight portion 4 of the core 1 is formed. The amount of attenuation in the resonance frequency band of the core is larger than that of the conventional case where the outer diameter of the core 1 is simply reduced at a constant reduction ratio (see FIG. 3). With a single winding inductor, a high attenuation can be obtained in a wider frequency band than ever before.

  Moreover, as described above, a high attenuation can be obtained in an unprecedented wide frequency band with a single winding inductor, so that it is not necessary to provide a plurality of winding inductors, and the cost is low and the installation space is small.

  Further, as shown in FIG. 1, the hyperboloid core 1 is provided with the conductor 2 as compared with the case where the conductor is simply wound around the conical core 1 as in the conventional example shown in FIG. Since it can be wound many times, for example, the size of the core 1 in the length direction can be set to be small so as to have a compact shape.

  As described above, the present embodiment is an epoch-making wire-wound inductor excellent in practicality that is extremely effective as this type of inductor.

  FIG. 4 shows the measurement results obtained by the experiment for evaluating the attenuation characteristics of the present embodiment described so far. The sweep signal is oscillated from the sweeper (sweep signal oscillator) to the receiver (receiver). However, the present embodiment type as shown in FIG. 1 (type in which the coil diameter is rapidly reduced on the base end side) and the conventional example shown in FIG. The result of having evaluated the attenuation amount (attenuation characteristic) with the network analyzer (high frequency measuring device) about both types to reduce diameter is shown.

The experimental conditions are as shown in FIGS. 5 (a) and 5 (b). That is, the length, the base end diameter, and the tip end diameter of the core 1 are the same, the length range in which the conductor 2 is wound around the core 1 is also the same, and the number of turns of the conductor 2 wound around the winding range is the present embodiment. The attenuation characteristics are evaluated by setting the example type to 80 times and the comparative product type to 76 times (both of which are wound with the conductor 2 without any gap).

  As can be seen from FIG. 4, the product of this example can secure a high attenuation characteristic of −30 dB or less over a wide range from around 30 MHz to around 10,000 MHz, while the comparative product attenuates from around 30 MHz. Although the amount is −30 dB or less, the attenuation is about −28 dB higher than −30 dB in the vicinity of 300 MHz. Thus, the product of this embodiment can secure a high attenuation characteristic in a wide range as compared with the conventional example.

  Note that the present invention is not limited to this embodiment, and the specific configuration of each component can be designed as appropriate.

It is explanatory front sectional drawing which shows the winding type inductor which concerns on a present Example. It is explanatory front sectional drawing which shows another example of the winding type inductor which concerns on a present Example. It is explanatory front sectional drawing which shows a prior art example. It is explanatory drawing which shows the measurement result of the experimental example of the winding type inductor which concerns on a present Example. It is a shape comparison figure of each winding type inductor used for the experiment example of the winding type inductor which concerns on a present Example.

Explanation of symbols

1 Core 2 Conductor 3 Tapered Part 4 Straight Part

Claims (4)

  A winding type inductor formed by winding a conducting wire around a core, wherein the core has an outer diameter that is gradually reduced so that the winding diameter of the conducting wire wound around the core is not constant but gradually decreases. The taper has a tapered portion with a small diameter, and the tapered portion has a taper in which the outer diameter of the core is reduced at a constant reduction ratio from the large diameter proximal end to the small diameter distal end of the tapered portion. A wound inductor having a tapered shape in which the diameter reduction ratio of the outer diameter of the core gradually decreases from the large diameter base end of the taper-shaped portion toward the small diameter distal end without being shaped. .   A wire-wound inductor formed by winding a conductive wire around a core, wherein the core has a gradually reduced outer diameter so that the winding diameter of the conductive wire wound around the core is not constant but gradually decreases. The taper has a tapered portion with a small diameter, and the tapered portion has a taper in which the outer diameter of the core is reduced at a constant reduction ratio from the large diameter proximal end to the small diameter distal end of the tapered portion. Without the shape, the outer diameter of this core is abruptly reduced on the large base end side of the tapered portion, and the diameter of the core is gradually reduced on the small end side compared to the large base end side. A wound inductor characterized by being formed into a tapered shape.   When the diameter reduction ratio of the outer diameter of the core in the tapered portion is R, the axial length of the core is x, and the outer diameter is r, the diameter reduction ratio is represented by R = −dr (x) / dx. The tapered portion is formed in a tapered shape in which the reduction ratio of the outer diameter of the core in the tapered portion is at least R ≧ 0. The wire wound inductor according to any one of the above. 2. The core according to claim 1, wherein the core has a straight portion having a constant outer diameter, and the outer diameter of the core is reduced by the tapered portion from an end of the straight portion. The wound inductor according to any one of?

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